The East Antarctic Ice Sheet (EAIS) has its origins ca. 34 million years ago. Since then, the impact of climate change and past fluctuations in the EAIS margin has been reflected in periods of extensive vs. restricted ice cover and the modification of much of the Antarctic landscape. Resolving processes of landscape evolution is therefore critical for establishing ice sheet history, but it is rare to find unmodified landscapes that record past ice conditions. Here, we discover an extensive relic pre-glacial landscape preserved beneath the central EAIS despite millions of years of ice cover. The landscape was formed by rivers prior to ice sheet build-up but later modified by local glaciation before being dissected by outlet glaciers at the margin of a restricted ice sheet. Preservation of the relic surfaces indicates an absence of significant warm-based ice throughout their history, suggesting any transitions between restricted and expanded ice were rapid. Using satellite and survey data, an ancient river landscape 300 km wide has been discovered buried and preserved beneath the ice in East Antarctica. It has likely survived largely intact for up to 34 million years since before ice sheet growth. However, a step-change in ice extent and volume occurred at the Eocene-Oligocene transition 20 and potentially the Pleistocene interglacials of MIS 11c (ca. 430–400 ka)21 and 5e (ca. 125 ka)24. Numerical ice sheet models indicate that retreat may have been focussed in low-lying marine-based sectors of the EAIS, such as the Wilkes and Aurora Subglacial Basins  surveying, can therefore be used to infer past processes of landscape evolution and former ice dynamics35. Processes that may be reflected in the subglacial landscape include but are not limited to, glacial erosion, solid earth adjustments to erosional unloading, and fluvial incision under scenarios of more restricted EAIS extent36. Accordingly, interpreting the morphology of the East Antarctic subglacial landscape and its long-term evolution offers a significant and hitherto relatively little exploited opportunity for understanding the past extent, fluctuations, flow, and thermal regime of the EAIS.Much of the evidence for past ice margin fluctuations and dynamic change of the EAIS is derived from global records of sea-level change and/or ice volume33. Young et al.37 identified palaeo fjord landscapes cutting the highlands that bound these basins  surfaces between the fjords, which may be more ancient features preserved beneath the EAIS. Our overarching aim is to evaluate the evolution and age of these land surfaces and to assess their implications for EAIS history.Here we use geophysical data to analyse an area in East Antarctica with a subglacial landscape that appears to be at odds with the modern ice sheet. It lies adjacent to the low-lying Aurora and Schmidt Subglacial Basins and inland of the Denman and Totten glaciers; a sector of the EAIS known to be sensitive to past and potentially future climate and ocean warming Fig. 13,33. Yoins Fig. , interpr39  evaluate our findings in the context of modern and past ice flow and basal thermal conditions.To test the hypothesis of an ancient land surface preserved beneath the modern EAIS, we quantify landscape characteristics from RES data collected as part of the International Collaborative Exploration of the Cryosphere through Airborne Profiling (ICECAP) airborne geophysical survey of the Aurora Subglacial Basin and Totten Glacier between 2008 and 201139 Fig. . To supp 40 Fig. ; (2) use 40 Fig.  to groun37. The blocks range between 121 and 173 km long and 73 and 85 km wide; each covers an area between ~7000 and 10,000 km2  with a long-axis of ~300 km. RES data confirm that across the three highland blocks, the buried topographic peaks have relatively uniform heights of 660–850 m above global mean sea level, with a subtle ‘domed’ pattern of tilting away from the southern and central blocks, which exhibit the highest elevations  over the blocks and slightly faster (~25 m yr−1) as it flows over the deeper basins surrounding our study area41. RADARSAT ice surface imagery42, calibrated with airborne RES data39, shows that the landscape blocks host a complex network of trunk and tributary valleys separated by sinuous mountain ridges, with valleys ranging between approx. 3 and 75 km in length  and approximately N–S (~330–20° / ~150–200°); Fig. 44.Figure 2). The approximate uniformity of these metrics across the three blocks is indicative of a coherent single land surface.The RADARSAT-derived valley networks also provide evidence for the potential coherency of the three blocks, as a number of N–S-trending valleys suggest a previous connection between the blocks Fig. . These cOur analysis indicates that valley structure therefore meets criterion #1 due to its similarity across the three blocks and because it is not consistent with modern continental-scale ice flow. The dendritic valley structure, potential connectivity of valleys across the blocks, valley-ridge relief/morphology, and valley cross-sectional profiles are all consistent with a fluvial landscape subsequently modified by local-scale glaciation.35. The spatial pattern of uplift is dependent on the chosen value of the effective elastic thickness of the lithosphere , the flexure exhibits short wavelength warping close to the margins of the large troughs that is not consistent with the observed elevations of the intervening highlands. By contrast, the flexure computed for higher Te values of 20–40 km predicts a pattern of uplift characterised by gentle domal tilting away from the deep trough between the southern and central blocks, within which the largest eroded thicknesses are predicted  drops off at high Te values46.The second criterion, that the elevation of the ancient surface should be coherent when corrected for more recent glacial trough incision and ice loading, was assessed using flexural modelling. Our calculations show that the displacement induced by erosional unloading within the large-scale troughs and smaller-scale valleys has caused land surface uplift of up to 500 m . The computed maximum amplitude of the erosion-driven flexure is ~500 m, whereas the elevations of the highland peaks are up to 1500–1700 m above sea level under ice-free conditions Figs.  and 5. T−1), flows in a northwards direction across the blocks and does not appear to be topographically steered by the local valleys in our mapped landscape  at the onset zones of the Denman and Totten Glaciers is ‘steered’ around the highland blocks, with basal melting potentially occurring in the floors of the dissecting fjords47  to the Wilkes Land coast and potentially across to Australia prior to continental separation49. We expect this fluvial landscape to have been characterised by relatively low local relief (<800 m) and peak elevations approximately 1 km above sea level.The original landscape Fig.  likely d50. We suggest that faults between the three highland blocks may have been activated at this time  rift structures in East Antarctica, as well as uplift of the Australo-Antarctic passive marginime Fig. , with asime Fig. . The sim51 to deepen the valleys to ~800 m of relief and generate U-shaped cross-sectional profiles. Peaks were likely preserved beneath cold-based ice and experienced isostatic uplift due to erosional unloading within the valleys , thus enabling widespread preservation of the landscape whilst the ice in the deeper troughs and adjacent basins was contemporaneously warm-based.The ice sheet rapidly expanded to a continental scale Fig. . During Subsequent ice margin fluctuations may have occurred but none of these was sufficient to significantly alter the basal thermal regime or ice flow pattern over the highland blocks. Glaciological conditions amenable to landscape preservation therefore persisted.We propose that the following relative sequence of events is required to modify an original large-scale fluvial landscape to become a set of three remnant upland blocks separated by deep troughs. This landscape evolution scenario Fig.  requiresOur proposed landscape evolution scenario indicates that the most recent erosive modification of the three highland blocks was by local-scale glaciation. Since this modification must have occurred at a time of much-reduced EAIS extent relative to the present day, a key question for EAIS history is: when did this local-scale glacial erosion last occur? Here, we evaluate the likelihood of the landscape of local glaciation being older than four key ‘thresholds’ of geological age pertinent to EAIS evolution. We consider that the land surface has a likely age of at least 14 Ma based on the following logic:41  period since ca. 14 Ma and is therefore the most likely candidate for significant retreat of the EAIS via the Denman and Totten Glaciers, which would be necessary for modification of the landscape by local ice flow. However, ice sheet model intercomparison indicates that most models do not simulate such retreat in the Aurora and Schmidt Subglacial Basins under peak mPWP climate conditions60 unless marine ice cliff instability is invoked25. We therefore suggest that these surfaces predate the EAIS switch to cold polar conditions at ca. 14 Ma17.Third, the landscape is likely older than ca. 14 Ma. The mPWP (ca. 3.26–3.02 Ma) is likely the warmest  reflect glacial conditions immediately prior to the establishment of the first continental-scale ice sheet at the EOT10. Therefore, on the basis of this evaluation of the existing understanding of Antarctic Cenozoic glacial history, we conclude that the Highland A land surface was last incised by local valley glaciers at least prior to ca. 14 Ma and possibly immediately prior to the initial growth of continental-scale ice at 34 Ma.Finally, there remains a possibility that the landscape is older than ca. 34 Ma. This is because after East Antarctica was initially glaciated following the EOT, the extent and chronology of fluctuations of the ice margin are uncertain61, ancient landscapes can survive beneath the EAIS for periods of at least several million years and likely much longer. In order for this to be possible, the transition between two glacial states—(1) local-scale glaciation with warm-based erosive glaciers cutting U-shaped valleys and (2) a continental-scale ice sheet which is locally cold-based and preserves the landscape of local glaciation—must occur rapidly. Previous modelling of ice sheet growth has demonstrated rapid ice expansion and a snap-change in basal thermal regime from warm- to cold-based occurred in the Gamburtsev Mountains region at the EOT10, meaning they were eroded very little62 and we propose a similar mechanism to have occurred across Highland A. Such rapid changes in ice extent and dynamics are supported by recent ice sheet-climate modelling63, where over a period of a few million years, either side of the EOT simulated ice volumes oscillate between local- and continental-scale in a quasi-binary and geologically near-instantaneous manner. During the growth of the EAIS, it is therefore possible that ice existed in a relatively small local form capable of eroding the Highland A land surface or at a continental scale that preserved the landscape of local glaciation, with little time in between.The presence of this preserved landscape has implications for understanding long-term EAIS behaviour. As previously shown in other regions of Antarctica64. The survival of the relic landscape implies that there is long-term thermal stability over these blocks of ancient terrain, with cold-based ice being the average glacial condition since landscape formation. If the ice margin were to have retreated substantially into the Aurora and Schmidt Subglacial Basins during significant past warm intervals such as the mPWP, independent ice masses remaining on the highland blocks would likely have been drained radially by outlet glaciers. We do not see evidence of radial drainage, but instead a more complex dendritic pattern and therefore deem it likely that the ice margin has never retreated far enough to enable this region to become an independent ice centre. If our interpretation is correct, this landscape may have survived because any retreat of this sector of the EAIS during past warm periods did not extend as far inland as these highland blocks, which are ~300 km inland of the modern-day grounding line. We note, however, that this landscape is likely not sensitive to, and therefore does not preclude, fluctuations within 300 km of the modern ice margin33.The preserved landscape we identify is somewhat unique given that it lies on the periphery of one of the ‘great basins’ of East Antarctica, which are of substantial interest as potential locations of past/future margin retreat via marine ice sheet instability17. Sampling of subglacial bedrock and potentially subglacial sediment would help better constrain the landscape age and we propose that given this region may not have been subject to significant erosion or basal transport for millions of years, it may be a promising area to recover a deep ice and subglacial sediment core in order to understand glacial conditions during those times. In addition, a more detailed local RES survey would help resolve the elevation and geometry of potential cirque floors31, which could then be used to constrain the climate that supported local-scale glaciers on the landscape. Such a survey could be directed by our ice surface feature mapping  planform and was once a continuous land surface that has since been dissected by deep glacial troughs that may inherit earlier tectonic weaknesses. Cross profiles of the terrain from RES data indicate that this fluvial landscape has been modified by local-scale glaciers and has not been modified by ice flowing at a continental scale. The age of the land surface is uncertain, but it is likely to predate the mid-Miocene (ca. 14 Ma) and perhaps dates from the transition from warm to glacial conditions in Antarctica following the EOT at ca. 34 Ma. The survival of the landscape implies a long-term stable basal thermal regime and that the ice margin is unlikely to have retreated as far inland as this locality during warm periods of the last 14 Ma. The landscape is more consistent with the idea that this region of East Antarctica requires greater warming than seen in  the mPWP for retreat to reach this far into the Aurora-Schmidt subglacial basins.2 and temperature conditions have reached levels unprecedented since the Pliocene66, we are now on course to develop atmospheric conditions similar to those that prevailed between 34 and 14 Ma (ca. 3–7 °C warmer than present), with CO2 conditions reaching above 500 ppm between now and 2100 under continued fossil fuel burning67. Under such anthropogenic forcing and the associated global heating, our work suggests the EAIS may eventually retreat enough that local ice caps would once again exist on ancient preserved landscapes at the margin of the Aurora and Schmidt basins.Given that modern atmospheric CO32 and Jamieson et al.40, we use satellite remote sensing to map the likely ridge and valley structure of the Highland A region. We use contrasts in the RADARSAT42 and REMA68 ice surface datasets to infer minor changes in ice surface slope, which are a consequence of buried topography. RADARSAT imagery records the brightness or intensity of the reflection of the satellite-emitted radar signal, which depends on the angle of the surface slope. Typically, subglacial valleys are positioned below darker areas (lower reflection intensity) and subglacial ridges below lighter areas (higher reflection intensity) in the RADARSAT image.Following the approach of Ross et al.REMA is an ice surface DEM; we calculate the plan and profile curvature of the DEM to identify breaks in slope that are indicative of subglacial valleys and ridges. In some locations, the change in ice surface brightness/curvature is abrupt, for example, where potentially sharp ridges or peaks are present beneath the ice. In other areas, the contrast is significantly muted, making mapping more challenging and less certain, particularly when attempting to determine valley/ridge orientations.Using the processed REMA and RADARSAT images, we digitise the locations of valleys and ridges where clear breaks in slope or changes in radar reflection intensity occur. Connections between valleys are inferred such that if a valley is continuous across an entire block, it is then connected to the next block if this block hosts an apparently contiguous valley on the other side of the intervening trough. Within each topographic block, the spatial statistics for the mapped valleys are calculated, including their length, the ridge-valley spacing, and the drainage density .39. Data were focused following the approaches described in Peters et al.69. Using the focussed RES lines, we automatically extract ridge and valley locations along each RES line as the points of maximum and minimum elevation within a 10 km-wide moving window, respectively. The ridge and valley locations are used to ground-truth the locations of the features mapped from the REMA and RADARSAT data. We also determine the mean relief  within the three landscape blocks. In addition to identifying the locations of ridges and valleys, we qualitatively examine the RES lines to identify whether the valleys are U-shaped or V-shaped and thus assess whether the landscape records the erosive imprint of either local valley glaciers or rivers.The location and form of the valleys are then confirmed using the available HiCARS RES survey data70, we construct an accordant surface between the highland peaks. Peaks are identified as high points in the landscape within a circular moving window of diameter 10 km, and a smooth surface representing the land surface in the absence of valley incision is interpolated between these peaks  of the East Antarctic lithosphere. For simplicity, we assume a spatially uniform Te, allowing Eq. (46. We assume a Young’s modulus (E) of 100 GPa, a Poisson ratio (ν) of 0.25, a gravitational acceleration (g) of 9.81 m s−2 and densities of 2670 and 3330 kg m−3 for the eroded material (ρload) and mantle (ρmantle), respectively. Note that for erosional unloading, the material infilling and displaced by the flexure is air, so ρinfill and ρdisplace are set to 0 kg m−3. We perform the calculation for a range of constant Te values to test the sensitivity of the flexural response to lithospheric rigidity and compare the observed land surface elevations to the predictions of our elastic plate model for different Te values.The parameter wing Eq.  to be soPeer Review FileSource Data


PPC80, PPC82, and PPC84 inhibited pancreatic lipase (IC50 of 167–1023 µM) via competitive or mixed mechanisms. The activity of pancreatic α-amylase was suppressed by PPC80, PPC82, PPC84, PPC89, and PPC101 (IC50 of 162–519 µM), which acted as competitive or mixed inhibitors. Finally, PPC84, PPC89, and PPC101 also showed potent inhibitory effects on α-glucosidase (IC50 of 51–353 µM) as competitive inhibitors. The results suggest that these synthetic amino acid derivatives have inhibitory potential against digestive enzymes and may be used as therapeutic agents to control metabolic disorders.Over the last decades, the increased incidence of metabolic disorders, such as type two diabetes and obesity, has motivated researchers to investigate new enzyme inhibitors. In this study, the inhibitory effects of synthetic amino acid derivatives  on the activity of digestive enzymes were assessed using in vitro assays. The inhibitory effect was determined by the inhibition percentage and the 50% inhibitory concentration (IC The digestion of foods in the gastrointestinal tract of humans and animals is determined by the activity of enzymes that break down macronutrients into smaller molecules to be absorbed in the gut and used by the body . Some ofRegulation of nutrient absorption  through the inhibition of digestive enzymes is an effective manner to control metabolism. For example, acarbose can inhibit the activity of α-amylase and α-glucosidase enzymes by reducing glucose absorption and decreasing insulin secretion in postprandial glycemia, establishing a glycemic control mechanism associated with reduced glycosylated hemoglobin. This class of enzymatic inhibitors is indicated in patients with adequate fasting blood glucose and elevated postprandial blood glucose levels. In patients with impaired glucose tolerance, enzymatic inhibitors have been associated with a marked reduction in cardiovascular events and no risk of adverse side effects, such as weight gain or hypoglycemia . TherefoObesity is a complex disease that involves an abnormal or excessive accumulation of fat in the body and constitutes a public health problem worldwide . The conIn this context, the preparation of novel amino acid derivatives obtained from organic synthesis processes is a promising area that has been subjected to numerous biological studies. In addition to the functionalization of carboxylic and amine groups attached to the stereogenic center, the coupling of carbon side chains may also result in functional amino acid derivative drugs synthesized by conventional chemical reactions  . These dIn the present study, the inhibitory effects of synthetic amino acid derivatives on digestive enzymes were assessed using in vitro assays. This exploratory study may have predictive value for developing new therapeutic agents against metabolic disorders such as type two diabetes mellitus and obesity.The evaluated as amino acid derivatives, compounds PPC80 (342.52 g/mol), PPC82 (314.47 g/mol), PPC84 (287.40 g/mol), PPC89 (370.58 g/mol), and PPC101 (469.76 g/mol), were synthesized according to our previous report in the literature .p-nitrophenol palmitate, Triton-X 100, orlistat, porcine pancreatic α-amylase, 50 mmol/L Tris-HCl (pH 7.0), α-glucosidase, 100 mmol/L citrate-phosphate buffer (pH 7.0), acarbose, and p-nitrophenyl-α-D-glycopyranoside , while dimethylsulfoxide and starch . Unless noted, all chemicals utilized in the synthetic protocol were acquired from Sigma-Aldrich® Co., St. Louis, MO, USA, and used as received.The drugs and reagents used in this study were as follows: porcine pancreatic lipase, 50 mmol/L Tris-HCl buffer (pH 8.0), 2 and 25 mM NaCl. The p-nitrophenol palmitate substrate (8 mM) was dissolved in 0.5% w/v Triton-X 100. PPC80, while PPC82, PPC84, PPC89, and PPC101 amino acid derivatives and orlistat were solubilized in dimethylsulfoxide (DMSO) prepared at increasing concentrations ranging from 0.5 to 1.392 mM. A total of 100 µL of enzyme solution, 50 µL of p-nitrophenol palmitate substrate, and 50 µL of the amino acid derivative sample or orlistat were added to the microplate wells. Next, microplates were incubated at four different time intervals  in a water bath at 37 °C, and the reaction was stopped in an ice bath. All reactions were carried out in triplicate. The absorbance of the products was measured at 405 nm using a microplate reader .The pancreatic lipase inhibition assay was performed according to Santos et al.  with som2 and 1% starch. PPC80, PPC82, PPC84, PPC89, and PPC101 amino acid derivatives and acarbose were solubilized in DMSO prepared at increasing concentrations ranging from 0.15 to 1.590 mM. A total of 50 µL of enzyme solution, 50 µL of substrate, and 50 µL of amino acid derivative sample or acarbose were added to the microplate wells. Afterward, microplates were pre-incubated for 10 min in a water bath at 37 °C. A total of 100 µL of substrate was added to each well, and microplates were incubated at four different time intervals  in a water bath at 37 °C. The reaction was stopped using an ice bath. All reactions were carried out in triplicate. The absorbance of the products was measured at 405 nm using a microplate reader .The pancreatic α-amylase inhibition assay was carried out according to Freitas et al.  with som®, TP-Reader, Wuxi, China).The inhibitory effect against α-glucosidase was carried out according to Chelladurai and Chinnachamy  with somI%) was determined using “absorbance versus time” graphs. By means of linear regression, using the method of least-squares, the equations of the straight lines and the angular coefficients were obtained to determine the inhibition (I%) of the enzymatic activities by the equation:A is the angular coefficient of the straight-line equation (enzyme + substrate), a is the angular coefficient of the equation of the line (substrate), B is the angular coefficient of the straight-line equation (enzyme + substrate + sample), and b is the value of the angular coefficient of the straight-line equation (enzyme + sample).The percentage of inhibition (50) were determined through “response versus concentration” plots using the linear least-squares regression model.The 50% inhibitory concentrations  as a function of time (60 s). The absorbance values were converted into product concentration (µmol/L) using standard curves of glucose (α-amylase) and p-nitrophenol (pancreatic lipase and α-glucosidase). The value of the initial velocity (v0) of enzymatic reactions was estimated to create the “v0 versus substrate concentration” graph. Kinetic constants (mK and maxV) and slope were calculated, and the inhibition model was verified using Lineweaver–Burk plots ..Vmax equPhaseolus vulgaris) that inhibited pancreatic lipase in the range of 23–87%. Polylysine is a synthetic peptide that also acts as a lipase inhibitor, showing a remarkable inhibition (80%) on the activity of porcine pancreatic lipase at a concentration of 100 mg/mL [50 values below 50 µM.These findings are consistent with those of previous studies assessing the effects of amino acid and peptide derivatives on pancreatic lipase activity. Ngoh and Gan  identifi00 mg/mL . Further00 mg/mL  and hydr00 mg/mL  inhibiteThe results of the present study showed that PPC80 and PPC82 have inhibitory potential on the activity of pancreatic lipase, which may promote a reduction in intestinal fat absorption and potentially affect body weight . Therefo50 values  with IC50 values of 2.58 ± 0.08 and 2.62 ± 0.05 mM for GGSK and ELS, respectively [Ocimum basilicum) seeds that showed 36% inhibition on α-amylase [Glycine max) protein capable of inhibiting pancreatic α-amylase activity at IC50 values ranging from 0.16 to 8.30 mg/mL.An increasing number of studies have shown that synthetic compounds derived from amino acids and peptides exhibit an inhibitory action on α-amylase ,32,33. Tectively . Another50 = 51.00 ± 1.73 µM) was about 12-fold more potent than acarbose (IC50 = 639.00 ± 4.62 µM) against this enzyme . Furthermore, three peptides isolated from quinoa (Chenopodium quinoa) showed similar inhibitory activities against α-glucosidase [Acacia nilotica that exhibited potent inhibitory effects against α-glucosidase at low IC50 values (3.75 µg/mL).Several studies have reported the promising potential of amino acid and peptide derivatives as α-glucosidase inhibitors ,38,39. Fcosidase . Singh aThe human α-glucosidase is an enzyme found in the epithelium of the small intestine that catalyzes starch breakdown and the consequent release of glucose. Therefore, inhibition of this enzyme constitutes a promising strategy for reducing serum glucose levels in metabolic diseases, including type two diabetes . Our res50 values as low as 167 µM via competitive or mixed mechanisms. The activity of pancreatic α-amylase was suppressed by PPC80, PPC82, PPC84, PPC89, and PPC101, with IC50 values in a range of 162–519 µM, which acted as competitive or mixed inhibitors. In addition, PPC84, PPC89, and PPC101 also presented an inhibitory effect on α-glucosidase, with IC50 values as low as 51 µM acting as competitive inhibitors. The present study supports that amino acid derivatives are promising therapeutic agents for metabolic disorders, including type II diabetes and obesity. However, further pharmacological and toxicological investigations are needed to ensure their safe use as medicines.In summary, the results showed that PPC80, PPC82, PPC84, PPC89, and PPC101 amino acid derivatives are potential inhibitors of lipase, α-amylase, and α-glucosidase enzymes. For instance, PPC80, PPC82, and PPC84 inhibited pancreatic lipase with IC


For maritime navigation in the Arctic, sea ice charts are an essential tool, which still to this day is drawn manually by professional ice analysts. The total Sea Ice Concentration (SIC) is the primary descriptor of the charts and indicates the fraction of ice in an ocean surface area. Naturally, automating the SIC chart creation is desired. However, the optimal representation of the corresponding machine-learning task is ambivalent and discussed in the community. In this study, we explore the representation with either regressional or classification objectives, each with two different (weighted) loss functions: Mean Square Error and Binary Cross-Entropy, and Categorical Cross-Entropy and the Earth Mover’s Distance, respectively. While all models achieve good results they differ as the regression-based models obtain the highest numerical similarity to the reference charts, whereas the classification-optimised models generate results more visually pleasing and consistent. Rescaling the loss functions with inverse class weights improves the performance for intermediate classes at the expense of open water and fully-covered sea ice areas. The opening of the Northern Sea Routes linking the far East to Europe and the coasts of North America across the Arctic could disrupt global supply chains by decreasing the shipping time and costs substantially3. Despite decreasing sea ice cover, hazardous conditions will remain in the Arctic, and are believed to result in more dynamic ice conditions with increased mobility for particular high sea ice concentrations4. Thus, high-resolution sea ice charts detailing the ever-changing sea ice conditions are indispensable.The Arctic oceans are experiencing diminishing sea ice covers due to global warming5. This is a resource- and time-consuming endeavour, inspiring the need for automation. Further expanding the operation to a pan-Arctic scale, required for continuous trading routes across the Arctic, is challenging and necessitates an automatic solution. Sea ice is also mapped at other national ice services such as the Canadian Ice Service, the Baltic Sea Ice Services, the Greenland Ice Service and the Norwegian Ice Service, which would likewise benefit from automatic sea ice mapping.Synthetic Aperture Radar (SAR) images offer high-resolution, versatile acquisitions independent of sun illumination and clouds. However, they are difficult to interpret for untrained eyes; the radar backscatter is dependent on surface, material and volume properties, and ambiguities between open water and sea ice are common. Professional sea ice analysts at the Greenland ice service operated from the Danish Meteorological Institute (DMI) interpret these signatures to manually draw charts of the sea ice conditions around Greenland6 and continued in8. Newer advancements apply SAR and Passive Microwave Radiometer CNN data fusion models in the Automatic Sea Ice Products (ASIP) project10. de Gelis et al.11 is the first paper to adopt the U-Net CNN architecture12 in mapping sea ice using SAR data and ice charts as labels. This was closely followed by13 using SAR data to map SIC with labels retrieved from passive microwave radiometer data while also applying the U-Net architecture and curriculum learning. An alternative branch of sea ice charting, classifying the stage of development of sea ice, has been carried out in14. Finally, Stokholm et al.15 demonstrated that increasing the receptive field of the U-Net improves the resulting sea ice maps. In this study, we expand on the previous literature entries of mapping sea ice automatically using SAR data by analysing different representations of the CNN model’s optimisation objective to better capture the intuition of human-labelled sea ice charts.Using Convolutional Neural Networks (CNN) and SAR for automatic sea ice charting was originally published byexact percentage ratio of sea ice to open water for an area, discretised into 11 10%-bin classes ranging from 0% (open-water) to 100% (fully-covered sea ice). Training the model with classification loss functions, such as categorical Cross-Entropy (CE), may not reflect the inter-class relationship, penalizing the model disproportionately, e.g. if 60% is predicted instead of 50%, the penalty is equal to a prediction of 0%. Indeed, Stokholm et al.15 showed that (weighted) CE excels at predicting open-water and 100% sea ice but it often remained inadequate for the intermediate SIC classes (10–90%). Therefore, here we compare CE to Mean Squared Error (MSE), Binary Cross-Entropy (BCE) and squared Earth Mover’s Distance , as described in the DMI sea ice charts, is the 16.This work builds upon preliminary results previously presented at the International Conference for Learning Representations (ICLR2022) at the AI4EarthScience workshop5, compiled by DMI, the Technical University of Denmark (DTU), and Nansen Environmental and Remote Sensing Center (NERSC) and released October 2, 2020. It includes 461 co-located and georeferenced scenes distributed across the Greenland coast, but with the majority from the mid-Eastern, Southern and mid-Western coast and few in the North. The scenes were acquired between March 14, 2018, and May 25, 2019. We utilise the two layers; the Sentinel-1 dual polarised HH and HV SAR images and the corresponding professionally drawn SIC chart.The experiments are conducted with the European Space Agency’s (ESA) AI Ready Earth Observation (AIREO) sea ice dataset, AI4Arctic/ASIP v2 (ASID-v2)An example is showcased in Fig. 17. We use the medium resolution level 1 ground range detected data product, measured in the Extra-Wide operational mode with a pixel spacing of 40 m 20. Another study also suggests that low SICs (10–30%) are overestimated and high variability with a wide spread can occur in middle SIC classes (50–60%)21. A senior ice analyst at DMI has commented, that he was able to reliably identify, which of his staff had produced a given chart. Intermediate classes are particularly difficult to assess, and regions with potential for high maritime activity, such as the edge of the sea ice cover, receive more attention. Nevertheless, we treat the human-made SIC labels as ground truth and pixels are treated as equally valid in this work.Sea ice charts are snapshots of the ice conditions at acquisition time, drawn as polygons of fairly homogeneous sea ice areas, and based on the professional interpretation of the subsequent SAR images with identical image size. Charts follow the SIGRID3 (Sea Ice GeoReferenced Information and Data) created by the World Meteorological Organization. The process of shaping polygons and assigning the primary descriptive factor, SIC, albeit steered by common guidelines, is a creative and individual interpretation—studies suggest that ice analysts assign concentrations that can vary on average 20% and up to 60%306 training and 23 test scenes, each with up to In this paper, we study how the choice of loss function representation affects the performance of the model with respect to the given objective. Predicting the percentage concentration of ice in seawater, some argue, is a seemingly regressional problem, demanding the distance between the predicted and expected scalars minimised in a geometric sense using, for instance, the MSE.10. From this perspective, it is more natural to tackle the problem as a logistic regression one, treating the SIC values as confidence levels of sampling ice rather than water. This can be executed with BCE loss, for example.Alternatively, assuming that the sea surface may only consist of water or ice, we may view SIC as the (percentage) probability of sampling an ice fragment from a given sea surface region, as argued in15.Others will claim, that the main issue with the two approaches above is that SIC does not represent a continuous value. Furthermore, the discrete classes are not derived by quantifying well-defined physical properties. Instead, they reflect the intuition and experience of professional ice analysts. Therefore, sea regions with a fixed ice concentration can still be assigned to varying SIC classes, and also the size or shape of the region itself can vary. To illustrate the former, let us consider the continuous value of human age and the idea of someone being either young or old. A person of age 30 can be classified as both young or old, depending on their characteristics and on who is judging. Analogously, it may be more appropriate to represent SIC segmentation as a classification problem, using CE loss, for example, as attempted in Stokholm et al.However, the main counterargument against CE classification is the perceptible flaw that it assumes the lack of correlation between class predictions, which is not the case here. Let us recall the human age example: if we classify people as babies, kids, adolescents, adults, or elderly, then clearly the elderly group must be more correlated with the adults rather than the babies category. Therefore, a loss function that leverages the inter-class relationship is recommended in this instance. Therefore, we suggest an alternative; the w. We choose a weighting factor as the inverse class frequency and normalise it  in the training samples, which are otherwise discarded during the total loss computation. If we assess each sample as a batch of pixels, this is comparable to having a variable batch size at each iteration. To harmonise them, we discount each sample’s loss by the inverse of the number of its valid pixels. Analogous with associating a weight 1 with each valid and 0 with each masked pixel, and then calculating the per sample loss as a weighted average of per-pixel losses. Additional information on the (weighted) loss calculation and the variable number of valid pixels is detailed in “Models are initially evaluated quantitatively using accuracy, defined as the ratio of the number of correct predictions to the total number of predictions, and the For the quantitative assessment, masked pixels are excluded for evaluation. During training, we store model parameters after each testing cycle. Afterwards, we select the model version with the highest The distributions of entclass1pt{minimaThe overall best performing model for each loss category is selected, with the final mentclass2pt{minimExamining Table 20, the model may be in doubt regarding two classes, which are not equally represented (but close to), the model may choose to characterise both classes as the most frequently represented one. This may potentially lead to this strategy of betting on fewer classes. Inspection of the additional trained models indicates no systematic preference for the intermediate classes. Weighting the loss functions seem to somewhat mitigate the tendency for class preference. Additionally, Fig. Inspecting Table entclass1pt{minimaFor the qualitative assessment, 4 scenes are selected from the test scene subset and are illustrated in Fig. Figure The scene in Fig. The scene in Fig. The final scene in Fig. This study presents how different loss function representations affect model performances with respect to predicting the discrete percentage concentration of ice in seawater. We suggest four analogues: Mean Square Error and Binary Cross-Entropy for regressional representation and Categorical Cross-Entropy and the squared Earth Mover’s Distance for classification, are considered. In connection, an optional class weighting scheme for each loss function is presented.Overall, we see models trained with both regression and classification loss functions are capable of encapsulating the essence of assigning discrete 10% incremental SICs to areas of sea ice in SAR images. The models score well on the metrics and generate ice charts with a strong resemblance to the ground truth. We also observe unique advantages and disadvantages of the different optimization objectives.Quantitatively, we can rank the unweighted optimization objectives based on the chosen metrics as follows. For the mentclass2pt{minimQualitatively, we also note that despite the regressional models achieving higher This is surprising, as the inherent strong inter-class relationships represented in the regression-based optimized models do not necessarily lead to superior automatically produced sea ice charts, regardless of the intuitive expectation. This finding may reveal that despite the seeming continuity of the SIC, purely regression-based approaches explored in this study are inferior to classification with respect to mimicking the creative human endeavour associated with charting sea ice.However, in the classification setting, With respect to the optional weighting scheme, it leads to optimized models, which take precedence for intermediate SICs, with higher overall average and intermediate class accuracies. However, they create less detailed, more blurry charts, particularly along the ice edge and at chart polygons transitions. The unweighted-loss models’ performance both quantitatively and qualitatively is superior, but they tend to over-predict 100%. Given the modest improvement in the intermediate classes, weighting the loss functions may not justify sacrificing the performance in the 0% and 100% classes, which are the most abundant and important classes.Identifying an approach to improve intermediate SICs performance while retaining high accuracies in 0% and 100% could be relevant for future work. Other topics could involve balancing the dataset, sampling more intermediate SICs or decoupling them from the 0% and 100% classes during the training, such as dividing the SIC assignment into subtasks or reducing the number of classes by combining them, which could provide improvements, regardless of the choice of the loss function. The more numerically similar maps produced by the 12 with 8 encoder-decoder blocks (16 and 32 filters in the first two and 64 filters in the remaining) for 100 epochs, each with 500 batches (training steps), where a batch consists of 32 patches, each randomly cropped from a random training scene. Each patch consists of We train a U-Net22 and is predicted in 6 s, constituting a testing duration of about 2 min. All the experiments were carried out on two Nvidia TeslaV100 SXM2 32 GB GPUs using PyTorch 1.8 library. A full model training cycle takes 19–22 h.We train using the Adam optimiser with a fixed learning rate and default PyTorch hyperparameters. The testing is performed on entire unaugmented scenes, as recommended inIn the ASID-v2 dataset, ice charts are compiled as polygons with an ice code for a look-up table containing multiple sea ice parameters for each specific polygon, such as SIC, partial concentrations, stage of development etc. The 14 different available concentration classes in the original ice chart are compressed into 11 different classes from 0 to 100% in discrete increments of 10% (class 0–class 10).15, the ASID-v2 scenes are further preprocessed. SAR images are downsampled from 40 m to 80 m pixel spacing by applying a Using the same setup as in Stokholm et al.15. Batches are augmented using the open-source Python imgaug module23. Every batch is given a random set of augmentations independently for every patch and identical for both SAR and ice chart. Augmentations utilized are the dihedral group: 0, 90, 180, or 270-degree rotations, and horizontal, vertical, and two diagonal flips, i.e. 8 in total. In addition, there is a 50% chance of applying between 1 and 4 affine transformations with a random bounded magnitude;  degrees of rotation, ± 30% scaling, ± 30% translation, and ± 10 degrees of shearing. The applied data augmentation limit the number of identical patches that the model sees and thus provides provide additional variation to the data. This can help minimize potential model overfitting.Each batch is compiled of 32 Wasserstein’s or Earth Mover’s distance (EMD) between two distributions P and Q may be defined asP and Q, and P and Q are defined25. The reason behind the EMD name is that we can view it as the cost of optimally transporting “earth mass” between x and y26. An obstacle in using the EMD as the objective function is the infimum in  to the Mallows distance:31. The authors recommend using the squared EMD , i. Without the loss of generality, we assume that the unweighted loss is obtained when w is uniformly equal to 1 for valid classes (i.e. class 0–10).To address the two issues of class imbalance and the variable number of valid (i.e. not masked) pixels in each training sample, we define the per example (patch) loss function asWeighting the BCE and


Upon phosphorylation of the platelet immunoreceptor–based activation motif of the glycoprotein VI (GPVI)/Fc receptor gamma chain collagen receptor, both the tyrosine phosphorylation and activity of Syk are increased leading to downstream signaling events. Although it has been established that the activity of Syk is regulated by tyrosine phosphorylation, the specific roles of individual phosphorylation sites remain to be elucidated. We observed that Syk Y346 in mouse platelets was still phosphorylated when GPVI-induced Syk activity was inhibited. We then generated Syk Y346F mice and analyzed the effect this mutation exerts on platelet responses. Syk Y346F mice bred normally, and their blood cell count was unaltered. We did observe potentiation of GPVI-induced platelet aggregation and ATP secretion as well as increased phosphorylation of other tyrosines on Syk in the Syk Y346F mouse platelets when compared to WT littermates. This phenotype was specific for GPVI-dependent activation, since it was not seen when AYPGKF, a PAR4 agonist, or 2-MeSADP, a purinergic receptor agonist, was used to activate platelets. Despite a clear effect of Syk Y346F on GPVI-mediated signaling and cellular responses, there was no effect of this mutation on hemostasis as measured by tail-bleeding times, although the time to thrombus formation determined using the ferric chloride injury model was reduced. Thus, our results indicate a significant effect of Syk Y346F on platelet activation and responses  Signaling is initiated in many immune cells through clustering of immune receptors. Once clustered, their cytoplasmic tails are phosphorylated on tyrosines in a stretch of amino acids known as an immunoreceptor tyrosine activation motif (ITAM) containing two YXX(L/I) sequences , 2. ReceThe 72-kDa Syk protein is made up of the N terminally located tandem SH2 domains separated by the interdomain A and a kinase domain located in the C-terminal half. The tandem SH2 domains and the kinase domains are separated by the interdomain B. Syk recruitment to the activated receptor involves the binding of its tandem SH2 domains to the phosphorylated ITAM (pITAM) or hemITAM. Syk contains numerous phosphorylation sites which regulate both its activity and provide a docking site for other proteins. Syk binding to pITAM triggers a downstream signaling cascade Platelets are anucleate cells that are produced by megakaryocytes . Their mvia its two SH2 domains as it binds to other ITAM-containing receptors . The phosphorylation of Y342 (D) and Y519/520 (C) was nearly abolished in the presence of Syk inhibitors in mouse platelets as was LAT (E) and PLCγ2 (F) phosphorylation. These data argue that Syk Y346 is directly phosphorylated by SFKs associated with the ITAM receptors. To ascertain the SFK responsible for the phosphorylation of Syk Y346, we activated Lyn KO platelets and Fyn KO platelets with CRP and measured Syk Y346 phosphorylation in the presence of PRT062607 (A and B). Phosphorylation of LAT Y191 (C) and PLCγ2 Y1217 (D) was abolished demonstrating the efficiency of PRT062607 in inhibiting Syk activity. It is interesting to note that Syk Y346 phosphorylation is not abolished in the CRP-induced Lyn KO platelets without PRT062607. Syk tyrosine residues, including 346, are also autophosphorylated upon activation of Syk. In the absence of Lyn, the effect on the phosphorylation of Syk Y346 is masked by the autophosphorylation events triggered by the activation of Syk by other SFKs. In order to appreciate the difference between direct phosphorylation and autophosphorylation of Y346, the autophosphorylation events should be blocked and, hence, Syk was inhibited with PRT062607. While other SFKs might be able to phosphorylate Y346 in the absence of Lyn, Figure 2B shows that Lyn is the predominant kinase that directly phosphorylates Y346. Hence, in the Syk contains several tyrosine residues that can be phosphorylated, and of these, Y342, Y346, and Y519/520 have been suggested to play a role in the regulation of Syk activity , 48. To  of Y342 D and Y51Y519/520 C was nea was LAT E and PLCnd PLCγ2 F phosphoRT062607 . Syk Y34RT062607 , A and BLAT Y191 C and PLCγ2 Y1217 D was aboA) through a commercial source (Cyagen). The Syk Y346F mutation was confirmed by performing PCR with a pair of specific primers followed by sequencing of the PCR products . WT mice demonstrated the TAT sequence corresponding to a tyrosine codon , the homozygous mutant mice exhibited the TTC sequence corresponding to a phenylalanine codon , and the heterozygous mice expectedly showed the T(T/A)(T/C) sequence . To confirm the Y346F mutation at the protein level, we isolated platelets from Syk Y346F and WT littermate control mice and stimulated them with CRP. We performed Western blot analysis to visualize phosphorylation of Y346 and observed a robust band in WT mouse platelets treated with CRP at any concentration but no band at the expected molecular weight in samples obtained from Syk Y346F mouse platelets . Taken together, these data demonstrate that we successfully produced Syk Y346F knock-in mice.Studies in several cell types indicated that Syk Y342 and Y346, located in the interdomain B (linker) region, are involved in the regulation of Syk activity and functions , 41, 42.Fig. 3Both heterozygous Syk Y346F knock-in mice and homozygous Syk Y346F knock-in mice bred normally and produced pups at expected Mendelian ratios. Blood cell counts were not altered in Syk Y346F knock-in mice .Table 1BA–C) or the purinergic agonist 2-MeSADP (D–F); this result is consistent with the lack of critical involvement of Syk in signaling through these platelet receptors. Because Syk activity is vital to platelet activation by GPVI agonists, we evaluated the effect of Syk Y346F on GPVI-mediated aggregation and secretion by activating platelets isolated from Syk Y346F and WT littermate control mice with varying concentrations of CRP. Our results indicated that there was no aggregation (A and B) or ATP secretion (A and C) in WT platelets at very low concentrations of CRP, whereas Syk Y346F platelets aggregated and secreted under these conditions. Furthermore, Syk Y346F platelets showed a significant increase in ATP secretion at the moderate concentrations of CRP compared to platelets from WT littermates. This enhanced response was not observed when a high concentration of CRP was used (A–C). We also evaluated alpha granule release by flow cytometry using P-selectin as a marker and demonstrated that alpha granule release was increased in Syk Y346F platelets compared to WT control platelets (D).Platelets from Syk Y346F mice respond normally to the PAR-4 agonist AYPGKF , A–C or 2-MeSADP , D–F; thregation , A and Becretion , A and Cwas used , A–C. Welatelets D.Figure A–E). Contrary to the aggregation and secretion data, the phosphorylation of Syk Y519/520, Syk Y342, LAT Y191, or PLCγ2 Y1217 was enhanced at all concentrations of CRP tested. Extracellular signal-regulated kinase (ERK) phosphorylation was also enhanced in Syk Y346F platelets at all CRP concentrations tested (G), while Akt (Protein kinase B) pSer473 and pleckstrin phosphorylation mimicked the aggregation pattern (F and H). These data collectively indicate that signaling downstream of GPVI is enhanced in Syk Y346F platelets.Syk is an essential component of the signaling pathway downstream from ITAM-bearing receptors , 32, 33.s tested G, while  pattern , F and HWe have evaluated the effect of pan-Src kinase inhibitor PP2, and the data are shown in A–C).Syk is also crucial for hemITAM-dependent signaling initiated through the CLEC-2 receptor , 52, 53.A–E). We also evaluated the effect of Y346 phosphorylation on the Akt and ERK pathways. As seen in A, E, and F, Akt and ERK phosphorylation was increased in the Syk Y346F platelets compared to the WT control platelets at lower concentrations of the CLEC-2 agonist. Pleckstrin phosphorylation, indicative of calcium mobilization, was also increased in the CLEC-2–activated Syk Y346F platelets.Since Syk is also a crucial component of the signaling pathway downstream from hemITAM-bearing receptors, we analyzed similar proteins as we did with GPVI stimulation. After activation of the CLEC-2 receptor, there was phosphorylation of Syk Y519,520, Syk Y342, LAT Y191, and PLCγ2 Y1217 in WT platelets, but the phosphorylation of these sites was statistically increased in the Syk Y346F platelets at lower concentrations of agonist , A–E. WeA). These data suggest that Syk Y346 phosphorylation exerts no effect on hemostasis. To determine whether thrombus formation is impacted by the impaired phosphorylation of Y346 on Syk, we injured the carotid artery in Syk Y346F and WT littermate control mice with 5% FeCl3 for 90 s and monitored its occlusion. Syk Y346F mice formed stable occlusion in statistically shorter time than the WT mice (B). These data suggest that the positive effect of the Syk Y346F mutation we observed for GPVI and CLEC-2 mediated signaling and platelet responses in vitro moderately but significantly potentiates thrombus formation in vivo.To determine the impact of Syk Y346F on hemostasis, we performed tail-bleeding assay on litter-matched WT, heterozygous, and homozygous Syk Y346F mice. We found no significant differences in the bleeding times A. These  WT mice B. These It has been known that Syk is phosphorylated on multiple tyrosine residues and many of these residues exert regulatory effects on Syk activity and Syk-mediated signaling , 19, 33.Phosphorylation of Syk Y346 by SFKs, of which Lyn appeared to be the most important, has been shown in mouse bone marrow–derived mast cells and the RBL-2H3 rat basophil/mast cell line . We havein vitro demonstrate somewhat differential dependence on a concentration of CRP, a GPVI receptor agonist, all responses are clearly upregulated at a suboptimal stimulation level  protein tyrosine phosphatase on Syk activation and Syk-mediated signaling in platelets appears to exceed that in other cells where TULA-2 downregulates Syk signaling, such as basophils/mast cells  and even Y525/526 (a human homolog of mouse Syk Y519/520)  , whose k519/520) , 48. Desse assay .in vivo  and anti-pPLCγ2 Y1217 were purchased from Cell Signaling Technology. Anti-pSyk Y352 (Y346 in mice) and anti-pSyk Y348 (Y342 in mice) were purchased from Abcam. Anti-Syk and anti-PLCγ2 were purchased from Santa Cruz Biotechnology. Ibrutinib was purchased from Selleckchem. Odyssey blocking buffer and secondary antibodies IRDye 800CW goat anti-rabbit and IRDye 680LT goat anti-mouse were purchased from Li-Cor. CRP-XL was purchased from Dr Richard Farndale at the University of Cambridge. AYPGKF was purchased from GenScript.Mice were housed in a pathogen-free facility, and all animal procedures were approved by the Temple University Institutional Animal Care and Use Committee (protocol #4864). Syk Y346F mice were produced by Cyagen on a fee for service basis.8 cells/ml in N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid-buffered (pH 7.4) Tyrode’s solution containing 0.2 U/ml apyrase.Mouse blood was collected and platelets were isolated as previously described . The resAll platelet aggregation and secretion experiments were carried out using a lumi-aggregometer (Chrono-log) at 37 °C under stirring conditions. Platelet aggregation was measured using light transmission, and ATP secretion was measured using Chrono-lume (a luciferin/luciferase assay).4 and washed with water prior to the addition of sample loading buffer. Platelet protein samples were then boiled for 5 min prior to resolution by SDS-PAGE and transfer to nitrocellulose membranes. The membranes were then blocked using Odyssey blocking buffer and incubated overnight with primary antibodies against the indicated protein. The membranes were then washed with Tris-buffered saline containing 0.1% Tween-20 prior to incubation with appropriate secondary antibodies for 1 h at room temperature (RT). The membranes were washed again and imaged using a Li-Cor Odyssey infrared imaging system.Western blotting procedures were performed as described previously . Briefly6 platelets was gently mixed with 10 μl FITC-anti-P-selectin (Emfret) and incubated for 15 min at RT. Platelets were fixed with 1% paraformaldehyde in PBS.Surface exposure of P-selectin in murine platelets was determined as previously described . BrieflyFor surface expression of GPVI  and αIIβ (CD41), aliquots of murine washed platelets were incubated with 10 μl of the corresponding antibody for 15 min at RT and treated as above. All determinations were performed on a FACSymphony flow cytometer (BD Scientific).Mouse tail bleeding was conducted as previously described . Mice ag3 was used to injure the carotid artery as previously described (3 for 90 s. The filter paper was removed, and blood flow was recorded.FeClescribed . Mice agt test where p < 0.05 was considered statistically significant. All the data are presented as means ± SD of at least three independent experiments.All statistical analysis was performed using Microsoft Excel, and data were analyzed using a Student’s All data concerning this report are available in the manuscript.This article contains The authors declare that they have no conflicts of interest with the contents of this article.


Objective: In this study, the advantages of the internal fixation configuration composed of uniplanar pedicle screws in the treatment of thoracolumbar fractures were verified by biomechanical experimental methods, which provided the basis for subsequent clinical experiments and clinical applications.Methods: A total of 24 fresh cadaveric spine specimens (T12-L2) were utilized to conduct biomechanical experiments. Two different internal fixation configurations, namely, the 6-screw configuration and the 4-screw/2-NIS (new intermediate screws) configuration, were tested using fixed-axis pedicle screws (FAPS), uniplanar pedicle screws (UPPS), and polyaxial pedicle screws (PAPS) respectively. The spine specimens were uniformly loaded with 8NM pure force couples in the directions of anteflexion, extension, left bending, right bending, left rotation, and right rotation, and the range of motion (ROM) of the T12-L1 and L1-L2 segments of the spine was measured and recorded to access biomechanical stability.Results: No structural damage such as ligament rupture or fracture occurred during all experimental tests. In the 6-screw configuration, the ROM of the specimens in the UPPS group was significantly better than that of the PAPS group but weaker than those of the FAPS group (p < 0.01). In the 4-screw/2-NIS configuration, the results were identical to the biomechanical test results for the 6-screw configuration (p < 0.01).Conclusion: Biomechanical test results show that the internal fixation configuration with UPPS can maintain the stability of the spine well, and the results are better than that of PAPS. UPPS has both the biomechanical advantages of FAPS and the superiority of easy operation of PAPS. We believe it is an optional internal fixation device for minimally invasive treatment of thoracolumbar fractures. With the increasing global aging population, the incidence of such fractures is on the rise. Pedicle screw and rod configuration is the most used surgical intervention. The surgery includes key steps such as fracture reduction and spinal stabilization. Fixed-axis pedicle screws (FAPS) have been the standard equipment for open internal fixation of the spine. However, during the operation of traditional open surgery, the soft tissue retraction may cause muscle crushing injury, destroy the muscle attachment point, In recent years, the use of posterior spine minimally invasive screw placement has become increasingly popular due to its effectiveness in addressing the limitations of traditional open surgery. By limiting the surgical approach’s breadth, minimally invasive surgery reduces soft tissue injury and the probability of postoperative low back pain and muscle weakening. FAPS must, however, be placed in the same plane and at the same depth during operation to allow for the connecting rod’s smooth insertion. The limited exposure of the minimally invasive surgical field and variations in surgeon expertise make inserting the connecting rod for FAPS challenging, resulting in increased operation time and variability in the operation’s outcome.Surgeons are continuously seeking new pedicle screw fixation systems that are more convenient for minimally invasive surgery while maintaining biomechanical advantages. Among the available solutions, the polyaxial pedicle screw (PAPS) has been commonly employed. However, its overall biomechanics are weaker than those of fixed-axis pedicle screws (FAPS), resulting in the loss of vertebral body anterior height during the healing process . We mustTo ensure the overall biomechanical advantage of internal fixation and facilitate minimally invasive surgical operations, we designed a new uniplanar pedicle screw (UPPS) . The scrIn addition, our previous conducted research using the finite element method and found that a four pedicle screws and two modified new intermediate screws (NIS) had similar biomechanical advantages compared to the six-pedicle screw configuration . This coIn this paper, the range of motion of the vertebral body in the T12-L1 and L1-L2 segments was measured using different internal fixation devices through biomechanical research methods. The biomechanical advantages of the UPPS internal fixation system were verified by comparing the differences in the vertebral body movements in the six spatial directions, including flexion, extension, left bending, right bending, left rotation, and right rotation. The following report presents the results of our research.The 3D model of UPPS was created using Solidworks software . This screw has an inner diameter of 4.1 mm and an outer diameter of 6 mm, and its hollow design enables minimally invasive insertion, with a 2 mm diameter hollow lumen. Unlike FAPS, the UPPS has a head-shank connection that allows for a ±30° range of motion on the body axis. Spot welding is used in the manufacturing process to minimize the movement of the head-shank in other directions.® cannulated schanz screw. The NIS design features threads situated at the one-third shank, with a smooth section in the middle.The new intermediate screw was developed based on the USSA total of 24 normal fresh cadaveric spine specimens (T12-L2) were carefully selected for this study. Each specimen was examined visually and with X-ray observation to ensure that no damage to the functional unit of the spine or abnormal bony structures were present. After removing the superficial muscle, fat and soft tissue, the inter-articular ligament and intervertebral disc structure were preserved. The specimens were then wrapped in double-layer plastic bags and stored at −20°C for later use. Prior to testing, the specimens were thawed at room temperature for 5 h. To create a model of fracture, cuneiform osteotomy was performed on the L1 vertebral body. The sample, test purpose, process, and post-test treatment process were approved by the Guangdong Provincial Medical Biomechanics Laboratory and related units, and all the procedures were carried out in accordance with the ethics guidelines established by the Chinese PLA General Hospital, Beijing, China.The biomechanical test comprised two parts. In the first part, we aimed to investigate the biomechanical differences among UPSS, FAPS, and PAPS for the short-segment 6-screw configuration, respectively. The three groups were labeled as follows:1) 6-UPPS 2) 6-FAPS 3) 6-PAPS. The second part of the experiment was designed to compare the biomechanical differences of the three types of pedicle screws in the 4-screw configuration with two-NIS. This was labeled as follows: 1) 4-UPPS/2-NIS; 2) 4-FAPS/2-NIS; 3) 4-PAPS/2-NIS . To ensuIn the first part of the experiment, 6 pedicle screws were inserted into each specimen, with two screws placed in each of the T12, L1, and L2 segments. The screws were all 6.0 mm in diameter and 45 mm in length and connected longitudinally by connecting rods without cross-links. A standard surgical procedure was followed by the same experienced surgeon, adhering strictly to the manufacturer’s specifications for screw placement.In the second part of the experiment, 4 pedicle screws were inserted into each specimen, with 2 screws placed in each of the T12 and L2 levels. The newly developed NIS screw was inserted laterally at the L1 level, which is hollow and has inner and outer diameters of 5.2 and 6 mm, respectively. The NIS screw was connected to the longitudinal rod connecting the T12 and L1 pedicle screws through a connecting device. The rest of the surgical procedure was the same as in the first part, and was performed by a deputy chief physician with extensive surgical experience.After the placement of internal fixation for each specimen was completed, the effectiveness of the placement was confirmed by taking an X-ray .To maintain the mechanical properties of fresh specimens and ensure accurate test results, the entire test procedure for each specimen must be completed within 8 h. In the event of ligament rupture, fracture, or intervertebral disc herniation, testing of the affected specimen must be discontinued, and a replacement specimen must be used for subsequent testing.The testing process is to place the specimen on the pure force couple loading table, fix the L2 vertebral body, and allow the T12 vertebral body to move freely. The T12 vertebral body is connected with the force couple loading link, and the 8NM pure force couple is uniformly loaded on the six degrees of freedom of flexion, extension, left bending, right bending, left rotation, and right rotation. The motion and force characteristics of the specimen are evaluated under the same loading conditions.The motion capture system and EVaRT software  were used to measure the absolute value of range of motion (ROM) of each segment of the specimen . The sysp < 0.05.Statistical analysis was performed using SPSS 19.0 software, and the results were presented in the form of mean ± standard deviation. Statistical differences between groups were compared using one-way ANOVA. Significance was defined as During the biomechanical testing of the 6-screw configuration, no instances of ligament rupture or bony structure compromise were observed in any of the specimens.p < 0.01)  . Besides < 0.01) .p < 0.01)  . The spe < 0.01) .During the biomechanical testing of the 4-screw/2-NIS configuration, no significant damage or destruction of load-bearing structures such as ligaments or bony structures were observed.p < 0.01)  . In addi < 0.01) .p < 0.01)  . The ROM < 0.01) .This study provides evidence that UPPS confers unquestionable biomechanical advantages in spinal surgery. Biomechanical testing of both 6-screw and 4-screw configurations revealed no damage or destruction to load-bearing structures such as ligaments and bones. Additionally, we measured the ROM of each spine segment in six degrees of spatial freedom. ROM partially reflects the mechanical stability of the fused vertebral body in biomechanical experiments. Our findings indicate that the use of UPPS screws results in superior biomechanical stability compared to PAPS models. These results have significant implications for the treatment of spinal pathologies with minimally invasive surgery, expanding the range of available surgical options.Minimally invasive spine surgery minimizes the incidence of postoperative low back pain and weakness in patients with open posterior spine surgery. Clinical application also verified the protection effect of the back muscles by the minimally invasive spine surgery. Kim et al. compared the trunk muscle strength of patients who underwent open posterior spinal fixation and those who underwent percutaneous internal fixation and found that the lumbar spine extension improved by more than 50% in patients who underwent percutaneous fixation, but not in patients who underwent open surgery . KawagucGiven the advantages of minimally invasive surgery, a matching pedicle screw design is required. The conventional FAPS is secured between the threaded section and the head, which provides high mechanical stability after vertebral body fusion. Our research further supported this claim. At levels of T12-L1 and L1-L2, FAPS screws had the least ROM values across all setups, indicating greater biomechanical stability. However, the use of FAPS requires precise alignment of the pedicle screw caps of each spinal segment on the same horizontal line to ensure insertion of the connecting rod. Unfortunately, the limited exposure of the minimally invasive surgical field and the challenging passage of the rod make it difficult to perform this task. Moreover, the already constrained operating environment is made even more constrained by the employment of the screw sleeve throughout the surgical procedure. This leads to prolongation of operation time and poor treatment outcomes in some patients. Thus, the benefits of minimally invasive surgery may be outweighed by the challenges posed by the FAPS system.In 2001, This study demonstrated that the ROM of the spine was the largest in the configuration composed of PAPS, indicating that the stability of the spine was worse. This is consistent with other research findings. Palmisani reported in a retrospective study that the use of polyaxial pedicle screws which are less rigid and might therefore increase the risk of loss of correction with time . A studyUPPS was designed to address the fixation challenges encountered during minimally invasive spine surgery, particularly in situations where the use of PAPS is not desirable from a biomechanical standpoint. Our findings support the notion that UPPS offers superior biomechanical benefits compared to PAPS. Although our experimental data show that FAPS has higher biomechanical stability than UPPS, there might not be a significant difference between the two in clinical practice. Yebin confirmed that the therapeutic effects of UPPS and FAPS were comparable in the follow-up period of 12–18 months through a retrospective research of 204 patients. Patients treated with UPPS experienced less intraoperative bleeding and spent less time in the hospital. Additionally, when it comes to restoring the anterior vertebral body’s height following surgery, UPPS and FAPS have comparable results . This deThe biomechanics benefits of UPPS have also been supported by earlier investigations. Ye and Luo compared the ultimate load of FAPS, UPPS, and PAPS for internal fixation failure in static and dynamic biomechanical tests. They confirmed that UPPS has better axial mechanical stiffness than PAPS, which can reduce the risk of loss of reduction . The useIntermediate screw have been developed to facilitate vertebroplasty and reduction maneuver . AccordiThere are several limitations to this study that need to be addressed. Firstly, the biomechanical specimens used in this study were derived from normal spines, and the biomechanical characteristics of pathological spines, such as those with osteoporosis, may differ. Secondly, this study did not test the ultimate load of internal fixation, which could provide additional information on the stability of the constructs. Additionally, there are various similar screws available in clinical practice, but this study only compared one type of FAPS and PAPS. These are issues that warrant more study.The biomechanical test findings revealed that the configuration employing the innovative UPPS had strong biomechanical benefits and assured spine stability. UPPS combines the biomechanical advantages of FAPS with the ease of use of PAPS. It is an optional minimally invasive internal fixation device for the treatment of thoracolumbar fractures.


The predictive performance of PLR and other derived indexes towards early-response was further improved by their combination with serum IgE concentrations, with a maximum AUC value for the combined systemic immune inflammation index (SII)-IgE of 0.797 . Derived inflammatory indexes, particularly SII-IgE, might be useful to identify early-responders to dupilumab and develop alternative treatment protocols for late/non-responders.Derived inflammatory indexes from routine hematological parameters might be useful for predicting early-response vs. late/non-response to dupilumab, the first biological agent approved for moderate-to-severe atopic dermatitis (AD). We tested this hypothesis by retrospectively investigating the association between pre-specified baseline inflammatory indexes and dupilumab response  at 4 and 16 weeks in a consecutive series of 66 AD patients . Forty-six patients (69.7%) were early-responders at 4 weeks, whereas the remaining twenty (30.3%) were late/non-responders at 16 weeks. In logistic regression, the platelet-to-lymphocyte ratio (PLR) was independently associated with early-response (OR = 1.0159, 95% CI 1.0005 to 1.0315,  Atopic dermatitis (AD), a chronic inflammatory skin disease affecting approximately 7–10% of adults and 20% of children in western countries ,4. Mild Routinely-derived blood cell inflammation indexes are gaining interest as they reflect the systemic inflammatory burden and may predict treatment response in specific disease states. In particular, several studies have highlighted the role of specific inflammation indexes derived from neutrophils, platelets, lymphocytes, and monocytes, e.g., the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) as biomarkers of disease, prognosis, and treatment response ,20,21,22We retrospectively studied a consecutive series of 66 AD patients commenced on dupilumab at the Dermatology Units of the University Hospital of Sassari, the Department of Medical Sciences and Public Health, AOU Cagliari, and the Department of Medical Care of San Francesco Hospital, Nuoro, between January 2020 and December 2021.Disease severity was assessed using EASI , the peaPatients were assessed at baseline and after 4- and 16-week treatment with 300 mg dupilumab every second week following a loading dose of 600 mg, as per product information. Treatment response was defined as a ≥50% reduction in the EASI score (EASI 50) . Early-rThe following demographic and clinical parameters were collected at baseline: age, sex, family history of AD, age of AD onset, and comorbidities including allergic symptoms affecting the eye and nose  and the airways (asthma and rhinitis). We also assessed the following simple blood cell count inflammation parameters: white blood cell count (WBC), monocytes, lymphocytes, neutrophils, platelets, red cell distribution width (RDW), and mean platelet volume (MPV). We then extrapolated the following derived indexes: NLR (neutrophil/lymphocyte ratio), dNLR [neutrophils/(white blood cells—neutrophils)], PLR (platelet/lymphocyte ratio), LMR (lymphocyte/monocyte ratio), SIRI  and AISI [(neutrophils × monocytes × platelets)/lymphocytes]. Finally, we collected information regarding baseline plasma IgE concentrations.t-test or the Mann–Whitney rank sum test were used to evaluate between-group differences of continuous variables. The Fisher test or the chi-squared test were used to assess differences between categorical variables. Relationships between variables were assessed by using the Pearson’s correlation or the Spearman’s correlation as appropriate. A p-value < 0.05 was considered statistically significant. The parameters that were significantly associated with early-response  were then combined by multiplying each of their values with IgE concentrations  in order to investigate their potentially superior predictive ability when compared to PLR, SIRI, AISI, SII, and IgE taken singly. SIRI-IgE and AISI-IgE values were further multiplied by a factor of 10−3 to facilitate data analysis and presentation. The predictive performance of the studied parameters and the optimal cut-off points for sensitivity and specificity were estimated by receiver operating characteristics (ROC) curve analysis and the Youden Index. A multivariate logistic regression analysis, using the “enter method” command, was performed to evaluate independent associations between the studied parameters and early-response vs. late/non-response status. In order to avoid collinearity bias, the independent predictive ability of each index was individually evaluated by adjusting for confounders with a p-value < 0.2 in univariate analysis . Statistical analyses were performed using MedCalc for Windows, version 20.014—64 bit .Data are expressed as mean values (mean ± SD) or median values (median and IQR). Variable distribution was evaluated using the Kolmogorov–Smirnov test. The Student’s A total of 66 AD patients  were included in the study . Forty-sp = 0.048), SII , SIRI  and EASI  were significantly higher in early-responders than late/non-responders. No significant between-group differences were observed in NLR, dNLR and LMR values . A non-significant correlation trend was also observed between baseline EASI and monocyte count .No correlation was observed between baseline EASI and simple or derived inflammation indexes, except for LMR . In multivariate logistic regression (p = 0.0204), combined PLR-IgE , SII-IgE , SIRI-IgE  and AISI-IgE  were significantly associated with early-response after correction for age at diagnosis, sex, and late onset.ROC curve analysis was performed to evaluate the sensitivity, specificity, and accuracy of derived inflammation indexes in identifying early-responders vs. late/non-responders . AUC valgression , IgE .To our knowledge, this is the first study that reports significant associations between baseline routinely blood-cell-derived inflammation indexes and early dupilumab response in real-world AD patients. Few studies have investigated predictors of dupilumab response in this group. Olesen et al.  reportedImportant limitations of our study include the small size of the cohort and the retrospective design. On the other hand, the involvement of different centers with real-world experience of new treatments ensures the generalizability of our results. Pending confirmatory studies, the use of combined inflammatory indexes that also incorporate IgE concentrations might be particularly useful in the identification of late/non-responders to dupilumab who might benefit from alternative biologics or adapted dupilumab protocols for the management of AD. In this context, newly derived haematological indexes that include other cell types, e.g., eosinophils, critically involved in the pathophysiology of AD, and/or specific eosinophil-related biomarkers offer additional opportunities for further research to enhance the capacity to predict treatment response in this patient group.


Preoperatively evaluating the feasibility of safe C2 pedicle screw placement is the key to avoiding iatrogenic vertebral artery injury. However, it has not been verified whether the conventional CT measurements of C2 pediculoisthmic component (PIC) are reliable and accurate, and the results may lack validity. The purpose of this study is to analyze the evaluative performance of conventional CT measurements and to create an accurate predictor of morphometrics of C2 PIC.A total of 304 C2 PICs were measured in 152 consecutive patients who underwent CT examination of the cervical spine between April 2020 and December 2020. We obtained the morphometric parameters of C2 PIC by measuring minimum PIC diameter (MPD) in CT multiplanar reconstruction versus conventional measurements of transverse PIC width (TPW), oblique PIC width (OPW) and definition of high-riding vertebral artery (HRVA). The outer diameter measured less than 4 mm in MPD was regarded as the standard of precluding safe C2 pedicle screw insertion. The evaluative performance of the conventional CT measurements was assessed, and the correlation between conventional CT measurements and measurements in CT multiplanar reconstruction was calculated.The parameters in OPW and MPD were measured significantly larger than those in TPW, and the preclusion of C2 pedicle screw placement evaluated from TPW and HRVA was significantly higher than that evaluated from OPW and MPD. The sensitivity of TPW was 93.09%, and the specificity was 79.31%. The sensitivity and specificity of OPW were 97.82% and 82.76%. The sensitivity of HRVA was 88.36%, and the specificity was 96.55%. Strong agreement with the highest correlation coefficient (0.879) and determination coefficient (0.7720) suggested that the outer diameter of OPW could be useful for the precise prediction of MPD.CT MPR allows accurate measurement of the narrowest section of the C2 PIC. The outer diameter of OPW could be simply measured and be useful for precise prediction of MPD, which makes C2 pedicle screw placement more safely than the conventional measurement of TPW and HRVA. Atlantoaxial instability may lead to severe neural and psychological injuries due to cervical spinal cord compression. Posterior atlantoaxial internal fixation can be used to fix and stabilize the occipitocervical junction to prevent neurologic damage , 2.Multiple techniques of posterior surgical fixation at the second cervical vertebra (C2) include transarticular screws, pedicle screws, pars screws, and more recently, translaminar screw fixation reported by Wright et al. . TransarThe key to a successful transpedicular procedure is that the small pedicle is safely penetrated. Otherwise, severe complications, such as iatrogenic vertebral artery injury, may occur, which can lead to potentially catastrophic results such as vertebrobasilar insufficiency, brain stem and posterior fossa infarction, and even death. Several studies have investigated the morphometry of the C2 pedicle isthmus. Many CT or CTA methods have been used to measure the morphometric parameters of the C2 pedicle isthmus to evaluate the feasibility of safe C2 pedicle screw or transarticular screw placement, including transverse C2 pedicle width, the definition of HRVA, variable angle interpolation of axial CT scans (oblique CT scans) according to Yin et al.  and so fYuan et al.  studied The purpose of this study was to analyze the feasibility of safe C2 pedicle screw placement by measuring the morphometric diameters with different CT method, and to create an accurate predictor of PIC morphology based on conventional CT measurements.We enrolled consecutive patients who underwent CT examination of the cervical spine at our hospital between April 2020 and December 2020. Patients with rheumatoid arthritis, ankylosing spondylitis, spinal metastasis or congenital cervical spine fusion, such as Klippel–Feil syndrome, and patients who had previously undergone head or cervical spine operation were excluded.The DICOM data collected from a 256-slice multidetector computed tomography scanner  were imported into DICOM viewer software . The settings used for the CT scans were as follows: helical mode; slice thickness, 0.4–2 mm; tube voltage, 100 kV; tube current, 340 mA; window center, 800; and window width, 2,000. We used the volume rendering (VR) and multiplanar reconstruction (MPR) functions of RadiAnt software. The linear precision of the measurements using the software was 0.01 mm. Safe C2 pedicle screw placement was not considered feasible in pedicles with < 4 mm outer diameter measured by conventional CT methods and CT multiplanar reconstruction.1) and outer diameter (TPW2) were measured perpendicular to the pedicle axis on the orthogonal axial plane  and outer diameter (OPW2) were measured in cross-sectional slices parallel to the sagittal pedicle axis  and outer diameter (MPD2) were measured at the narrowest sections of the PIC  and GraphPad Prism version 8.0.2 for Windows . A one-way ANOWA test was performed to compare the morphometric parameters of C2 PIC between TPW, OPW and MPD. A paired-samples A total of 304 consecutive C2 PICs were measured in 152 patients between April 2020 and December 2020. Eighty-seven were male (57.2%), and 65 were female (42.8%), with an age of 59.36 ± standard deviation (SD) of 13.73 years (range 16–87 years) at the time of CT scanning.P < 0.01). However, no significant difference was calculated between OPW and MPD . The HRVA was present in only the right PIC in 22 patients (36.7%), in only the left PIC in 38 patients (63.3%) and in both PICs in 11 patients (18.3%). A significant difference in the frequency of HRVA was noted between the left and right sides (P = 0.021).All measured data are shown in Table MPD Fig. a. A diffMPD Fig. b. The leP < 0.05).The comparison of the evaluative feasibility of safe C2 pedicle screw placement is shown in Tables κ = 0.60 , P < 0.001; McNemar P = 0.015). The sensitivity of TPW was 93.09%, and the specificity was 79.31%. Agreement on the feasibility of C2 pedicle screw insertion between OPW and MPD was strong . The sensitivity of OPW was 97.82%, and the specificity was 82.76%. Agreement on the feasibility of C2 pedicle screw insertion between the HRVA and MPD was weak . The sensitivity of HRVA was 88.36%, and the specificity was 96.55%.Agreement on the feasibility of C2 pedicle screw insertion between TPW and MPD was moderate  and MPD2 = 0.9179 × TPW2 + 1.522 at outer diameter .Simple linear regression analysis gave the following relationship between MPD and TPW: MPD1 = 0.9809 × OPW1 + 0.9425 at endosteal diameter , MPD2 = 1.058 × OPW2 + 0.4673 at outer diameter .Simple linear regression analysis gave the following relationship between MPD and OPW: MPDThe presence of an HRVA or narrowed C2 pedicle isthmus poses a great risk when placing a C2 pedicle screw. Preoperative evaluation of the pedicle isthmus size and clarification of the position of the vertebral artery are closely related to anatomic investigation of the C2 pedicle isthmus. Many surgeons recommend using CT images to evaluate the feasibility of C2 pedicle screw placement.With the development of CT techniques, several studies that focus on the morphology of C2 PICs by means of multiplanar reconstruction CT images have emerged. Marques et al.  proposedIn the present study, the mean MPD for endosteal diameter was 3.82 ± 1.58 mm and 6.54 ± 1.91 mm for outer diameter, which were similar to those of Yuan et al. , but theGiven that 80% of the outer diameter in C2 PIC would be exceeded by the inner diameter of screw rod ranging from 2.4 to 2.9 mm and that screw thread is allowed to cut into part of the PIC cortex , we regaFollowing the recommendation of Dull et al.  for preoForty-nine (32.24%) patients had preexisting HRVAs, accounting for 19.74% of all PICs. The sensitivity and specificity of HRVA were 88.36% and 96.55%, respectively. In other words, 3.45% of C2 PICs without HRVA that is actually not feasible for screw placement were misjudged, whereas 11.64% of C2 PICs with HRVA that can actually be placed a screw were omitted.The risk of vertebral artery injury due to misjudgment of C2 pedicle screw placement may be increased when the feasibility of screw placement is evaluated only from TPW. Conversely, when evaluating only the definition of HRVA, screw placement with relatively insufficient biomechanics, such as C2 pars screws, may be chosen because of preclusion of C2 pedicle screws. This was because the difference in measuring planes resulted from the irregular morphology of C2 PIC. First, the C2 PIC is a unique structure and presents a three‑dimensional inclination with a complicated space position. Xu et al.  measuredFrom the perspective of avoidance of vertebral artery injury, it is significant for surgeons to preoperatively estimate an optimal PIC diameter from reconstructed CT images. Our previous research had reported that MPD measurement with CTA multiplanar reconstruction showed the best performance for judging acceptable or unacceptable C2 pedicle screws . HoweverThe present study is retrospective, has a relatively small sample size and is nonmulticenter. Multicenter study in a larger cohort is needed to validate the results. Despite these limitations, to our knowledge, this is the first report to propose accurate predictors of PIC morphology based on measurements of conventional TPW and OPW for the evaluation of the optimal PIC diameter.CT MPR allows accurate measurement of the narrowest section of the C2 PIC. The outer diameter of OPW could be simply measured and be useful for precise prediction of MPD, which makes C2 pedicle screw placement more safely than the conventional measurement of TPW and HRVA.


Minimal change disease (MCD) is one of the most common primary glomerular disorders with high serum IgE levels. This study was aimed to investigate the clinical features of different serum IgE levels in pediatric MCD and evaluate the prognostic significance of serum IgE levels with regard to remission and relapse in pediatric cohort.This study enrolled 142 new-onset children diagnosed with biopsy-proven MCD from January 2010 to December 2021 at the Jinling Hospital in Nanjing, China. These cases were divided into three groups according to serum IgE levels. MCD patients’ demographics, clinical parameters, and follow-up data were collected and analyzed. The primary and secondary outcomes were defined as the time to the first complete remission (CR) and the first relapse.P = 0.032) and a higher rate of the first relapse  than the normal-IgE and low-IgE groups. Multivariate Cox analysis showed that IgE ≥597.5 IU/ml was independently associated with the delayed first CR  and the early first relapse .The results manifested that 85.2% (121/142) of MCD children had high serum IgE levels (IgE > 90.0 IU/ml). A total of 142 patients were divided into the normal-, low-, and high-IgE groups based on the normal reference value level (90.0 IU/ml) and median serum IgE level (597.5 IU/ml). The high-IgE group had a significantly lower cumulative rate of the first CR (log-rank, Serum IgE levels were an independent correlation factor for pediatric MCD-delayed remissions and early relapses. Minimal change disease (MCD), which approximately accounts for 70%–90% in children >1 year of age and 10%–15% adults, respectively, in idiopathic nephrotic syndrome (INS), is one of the most common primary glomerular disorders. The morphologic feature of MCD is foot process effacement .Numerous studies have reported a strong connection between INS and atopic disorders. Immunoglobulin E (IgE) is correlated with allergic reactions and elevated serum IgE levels are detected in patients with INS . Atopic Children (≤18 years) with MCD diagnosed by kidney biopsy were recruited from January 2010 to December 2021 in this retrospective study implemented by the Jinling Hospital. The indications for kidney biopsy in this cohort were as follows: (1) children first diagnosed with nephrotic syndrome (NS) at the age of ≥12 years; (2) children with steroid-resistant NS (SRNS); (3) children with atypical characteristics, involving macroscopic hematuria, not related to hypovolemia, hypertension, acute kidney injury (AKI), and rash that suggests glomerulonephritis; (4) steroid-sensitive NS (SSNS) patients evolving into secondary SRNS, steroid-dependent NS (SDNS), or frequent relapsing NS (FRNS) in the course of follow-up time. The study enrolled cases who met the following criteria: (1) 24-h urine protein to creatinine ratio (UP/CR) ≥2.0 g/g or ≥ 3+ on urine dipstick; (2) MCD patients with biopsy proven at any age between 1 and 18 years; (3) new-onset of disease or discontinuation of immunosuppressive therapy for more than 1 year. Individuals were excluded if they had any of the following conditions: (1) infectious diseases ; (2) individuals of connective tissue diseases, diabetes mellitus, malignant tumors; (3) drug-induced NS; (4) missing data on serum IgE levels at onset.All clinical data were obtained retrospectively from medical records. The baseline investigations were taken during the beginning of diagnosis. Follow-up data, including treatment, steroid response, time to the first complete remission (CR), and relapse, were collected and analyzed at 1, 2, 3, 6, and 12 months and longer follow-up. The last follow-up time was estimated as the last encounter in our follow-up system. The diagnosis of hypertension was based on the 2017 AAP Blood Pressure Clinical Practice Guidelines . eGFR wa2/day or 2 mg/kg/day). (2) Steroid-resistant NS was defined as a lack of CR for at least 4 weeks of standard dose of steroids. (3) SDNS was defined as follows: (a) two consecutive relapses during corticosteroid therapy or within 15 days of discontinuing corticosteroid therapy; (b) infectious factors should be excluded at the same time; (c) when relapse occurs, patients would reach CR again once the dose of corticosteroid is increased (either at full dose or beyond the relapse dose). (4) Partial remission (PR) was defined as a decrease in 24-h UP/Cr to <2 but >0.2 g/g (or >20 and <200 mg/mmol) with a 50% reduction from its peak value, or the test result of the dipstick decreases by at least 1+, but it did not reach negative. (5) CR was defined as a decrease in 24-h UP/Cr ≤0.2 g/g (or 20 mg/mmol or negative or trace dipstick) on three or more consecutive occasions. (6) Total remission (TR) was the achievement of PR or CR. (7) Relapse was defined as an increase in UP/Cr to ≥2.0 g/g in cases with a 50% increase from its valley value or in urine dipstick to ≥3+ after the remission. (8) Frequent relapse was defined as ≥2 relapses per 6 months or ≥4 relapses per 12 months.(1) SSNS was defined as CR within the 4 weeks standard dose of prednisone or prednisolone (PDN)  and 95% confidence intervals (95% CIs). All data were tested two-sided, with P < 0.05 regarded as statistically significant.SPSS (version 26.0) and Graph Pad Prism 8.0 were used for statistical analysis in this cohort study. The Shapiro–Wilk test was performed whether the continuous variables conform to the normal distribution. Continuous variables were represented as mean ± SD deviation or median . Categorical data were presented as frequency (percentage) and analyzed using the As shown in P > 0.05). In the high-IgE group, the proportion of AKI patients was significantly higher than in low-IgE group .The median serum IgE level of MCD patients was 597.5  IU/ml and 85.2% (121/142) patients had high serum IgE levels (IgE > 90.0 IU/ml) at onset. Based on normal value and median of serum total IgE, we divided patients into three groups including 35.2% (50/142) in the low-IgE group (90–597.5 IU/ml) and 50% (71/142) in the high-IgE group , compared to 14.7% (21/142) in the normal-IgE group (≤90 IU/ml). There were no statistically significant differences in onset age, gender, body mass index (BMI), hypertension, allergic history, proteinuria levels, and hematuria cases : 16.7% (12.8%–23.6%) vs. 10.3% (6.4%–19.47%) and 11.0% (9.6%–18.9%), P = 0.038]. The high-IgE group had higher neutrophils (NE)  and NE/Lymphocyte (LY)  .In the normal-IgE group, proportions of SSNS, SDNS, and SRNS were 66.7% (14/21), 23.8% (5/21), and 9.5% (2/21), respectively, while proportions in the low-IgE group were 50% (25/50), 38% (19/50), and 12% (6/50) and in the high-IgE group were 53.5% (38/71), 31% (22/71), and 15.5% (11/71), as shown in A total of 142 cases were followed up for more than 2 months and included to detect the predictors of the first CR.P = 0.032). Furthermore, we found a significant difference in the cumulative rate of the first CR between the high-IgE group and the normal-IgE group, which is presented in P = 0.014), SD , SR , AKI , and eosinophils count  were associated with the first CR. The result of the multivariate Cox regression analysis is listed in P = 0.039) and SR  were independently associated with the first CR within 2 months.As shown in A total of 127 patients with a follow-up of more than 1 year were included to detect the predictors of the first relapse.P = 0.045).In the normal-IgE group, proportions of no relapse (NR), infrequent relapse (IFR), and frequent relapse (FR) were 55.5% (10/18), 38.8% (7/18), and 5.5% (1/18), respectively, whereas that in the low-IgE group were 30.23% (13/43), 58.13% (25/43), and 11.6% (5/43) and in the high-IgE group were 25.7% (17/66), 48.4% (32/66), and 25.7% (17/66), respectively. As shown in P = 0.033). The mean time to first relapse in normal-, low-, and high-IgE groups were 18.45 ± 17.2 months, 13.13 ± 28.17 months, and 7.50 ± 22.23 months, respectively. The 3-month, 6-month, 1-year, and 2-year relapse rates were 18.18% vs. 5.5% and 13.95%, 40.90% vs. 22.2% and 30.23%, 59.09% vs. 27.77% and 48.83%, and 68.89% vs. 35.80% and 52.77% for the high-IgE group vs. normal-IgE group and low-IgE group, respectively. The univariate Cox regression analysis showed that high-IgE group  and serum albumin  were associated with the first relapse within 1 year. Other significant parameters in the univariate analysis included age at onset, SD, SR, and triglyceride (TG). As shown in P = 0.023), serum albumin  and TG  were independent risk factors with the first relapse within 1 year.This retrospective study assessed the serum IgE levels and correlated risk indicators in 142 Chinese children with MCD. So far, this study is the large-scale one in children with MCD and found that serum high levels of IgE were an independent risk factor delayed remission and an early relapse.Researchers had noted that patients with INS had a higher incidence of allergic diseases. Several patients had relapses of INS during asthma attacks or had undergone spontaneous remission of respiratory symptoms with hyposensitization therapy . A high There was a significantly higher occurrence rate of AKI in the high-IgE group of MCD, which was similar to a previous study . PreviouPrevious studies indicated that serum IgG level combined with serum IgE level could be served as prognostic clinical indicators of SSNS . It had The immune disordered Th cells in MCD could be subdivided into Th0, Th1, Th2, and other different cell subsets according to the different cytokines which they secrete. It was observed that the imbalance of Th1/Th2 cells was common in INS and pathogenesis of INS was closely related to the activation of Th2 . ActivatIn summary, this study found that serum IgE levels are an independent risk factor for delayed remission and relapse in pediatric MCD patients. These findings agree with the potential theory that the immune system is involved in the progression of MCD. Nonetheless, a frontier research study is needed to verify the function of IgE on MCD pathogenesis and theranostics.