With the change in people’s lifestyle, diabetes has emerged as a chronic disease that poses a serious threat to human health, alongside tumor, cardiovascular, and cerebrovascular diseases. α-glucosidase inhibitors, which are oral drugs, have proven effective in preventing and managing this disease. Studies have suggested that bioactive peptides could serve as a potential source of α-glucosidase inhibitors. These peptides possess certain hypoglycemic activity and can effectively regulate postprandial blood glucose levels by inhibiting α-glucosidase activity, thus intervening and regulating diabetes. This paper provides a systematic summary of the sources, isolation, purification, bioavailability, and possible mechanisms of α-glucosidase inhibitory peptides. The sources of the α-glucosidase inhibitory peptides were introduced with emphasis on animals, plants, and microorganisms. This paper also points out the problems in the research process of α-glucosidase inhibitory peptide, with a view to providing certain theoretical support for the further study of this peptide. According to the International Diabetes Federation, as of 2021, about 537 million people worldwide have diabetes, with a prevalence of more than 10% , and carGlycosidases are enzymes that play an important role in glucose metabolism. They can hydrolyze glucoside bonds and release monosaccharides. Glucosidase are the most important enzymes in the glycosidase family and their main functions are to hydrolyze glucosidase bonds and release glucose. Glucosidase can be divided into α-glucosidase and β-glucosidase according to the break mode of the glycoside bond. α-Glucosidase (E.C.3.2.1.20) includes maltase, isomaltase, glucoamylase, and sucrose and can bind to the membrane of small intestinal epithelial cells . The funBioactive peptides can be classified into natural peptides and synthetic peptides according to their sources . NaturalThe main preparation methods of α-glucosidase inhibitory peptides include enzymatic hydrolysis, microbial fermentation, and chemical methods ,20. ChemAfter producing α-glucosidase inhibitory peptides, different separation and purification techniques should be adopted to obtain the purified products . PurificTraditional methods have many problems in the analytical process: (1) Some peptides have very low levels in the mixture or interact with other components, which make their isolations and purifications very difficult; (2) Some highly active peptides may not be detected using conventional methods, especially those that target novel structures or mechanisms; (3) More experimental steps may be required, which will consume time and resources and, thus, increase the cost of investigation, especially when peptides are isolated and characterized on a large scale; (4) When large numbers of peptides need to be isolated from complex protein mixtures, traditional methods may not be appropriate, and there may be efficiency and scalability issues when purifying peptides on a large scale. To overcome these problems, new technologies and methods have emerged in recent years ,32,33,34Computer research is also known as “computer methods” or “bioinformatics”. Bioactive peptides are studied using databases and bioinformatics tools. It accelerates the process of discovery and design of α-glucosidase inhibitory peptides by predicting peptide structure, function, and interactions. These predictions are derived and analyzed by computers from existing experimental data. Bioinformatics technology plays an important role in the study of α-glucosidase inhibitory peptides and has great potential to further improve the current state of research. An increasing number of databases are being created and used and bioinformatics tools allow for a range of studies : (1) A lThere are several steps involved in assessing or predicting the role of α-glucosidase inhibitory peptides using bioinformatics . The firIn past studies, the focus of α-glucosidase inhibition peptides has shifted to identification and characterization, which are mainly derived from the partial hydrolysis of proteins from plants, animals, and microorganisms . As show50 values of 1.04 mg/mL and 0.59 mg/mL, respectively; LPTGWLM, MFE, and GPAHCLL were the most effective α-glucosidase inhibitory peptides [50 values of them were 23.07 μmol/Lol/L and 40.02 μmol/Lol/L, respectively. The new peptides, KLPGF (IC50 = 59.50 ± 5.70 μmol/Lol/L) and NVLQPS (IC50 = 100.00 ± 5.70 μmol/Lol/L), were identified from albumin with α-glucosidase inhibitory activity. Although KLPGF had a higher inhibitory effect on α-amylase than previously reported RVPSLM, it had a lower inhibitory effect on α-glucosidase [50 = 365.40 μg/mL). Zambrowicz et al. [Cucurbita ficifolia) protease, to isolate peptides from egg yolk protein by-products and the obtaining peptide LAPSLPGKPKPD had α-glucosidase inhibitory activity with IC50 = 1065.60 mmol/L. LAPSLPGKPKPD and the above-mentioned peptides share common features: the presence of P, S, and L residues in their sequences. It can be assumed that the presence of R residues at the C or N terminus of the peptide chain may result in high levels of α-glucosidase inhibition. Cheese, as an extremely popular dairy product, is rich in nutrients. It also is a potential raw material for the production of bioactive peptides. During cheese ripening, casein is able to produce small bioactive peptides via the action of rennet, proteases of secondary microflora, and peptidases [The proteins in dairy products have high nutritional value. They also contain a significant amount of animal-derived peptides and are considered to be a high-quality source of bioactive peptides. Milk-derived proteins are a precursor of bioactive peptides with various physiological functions. The main protein in milk is casein, which is around 80% of the total amount. Casein is structurally diverse with many sites exposed so that many proteases break down these proteins to form functional bioactive peptides. Numerous studies have shown that milk hydrolysates such as camel milk, cow milk, and goat milk have significant inhibitory effects on α-glucosidase. Casein hydrolysates extracted from bovine and camel milk were found to have a strong inhibitory effect on α-glucosidase, with ICpeptides . Similarpeptides . Among tpeptides . As a sopeptides  hydrolyzcosidase  hydrolyzz et al.  used Asiptidases . Researcptidases  or fermeptidases . The abo50 of 2.70 and 1.50 mg/mL). Zhang et al. [50 of 65.80 mol/L), SQSPA (IC50 of 20.00 mol/L), QPPT (IC50 of 560.0 mol/L), and NSPR (IC50 of 205.00 mol/L). QPGR could form hydrogen bonds with Lys776 in the active site ofα-glucosidase and SQSPA had potential interactions with Arg520, Lys519, and Asp777 of α-glucosidase. Compared with QPGR, QPPT and NSPR only form a single bond with Lys776 of α-glucosidase. In the three-dimensional structure, Lys776 is located at the edge of the α-glucosidase activity pocket and may be a key target for these peptides to inhibit α-glucosidase activity [50 = 206.00 μg/mL), SAAP (IC50 = 66.90 μg/mL), PGGP (IC50 = 63.50 μg/mL), LGGGN (IC50 = 42.93 μg/mL), YSFR (IC50 = 162.00 μg/mL) from the protein of Giant Salamander, and GPPGPA from skin collagen hydrolysates of Giant Salamander contained higher contents of Gly and Pro [50 = 5.95 μg/mL). These results suggest that some peptides composed of specific amino acids can be used as α-glucosidase inhibitors.Notably, some peptides composed of amino acids such as Gly, Ser, Glu, Tyr, Arg, Phe, and Pro are considered to be α-glucosidase inhibitors. Lee et al.  identifig et al.  used theactivity . SEDSSEVactivity ,76. In a and Pro ,48. This and Pro . The onlBacillus licheniformis alkaline protease; two peptides were finally screened for their α-glucosidase inhibitory activities: VW (IC50 = 22.60 mM) and WYPL (IC50 = 3.70 mM). In shellfish, VKP and VKK from Corbicula fluminea were effective in inhibiting α-glucosidase activity [Marine biological resources are abundant and the variability of the marine environment makes the composition and arrangement of amino acids unsuitable for terrestrial organisms. It causes them to produce substances with special physiological effects, which are an important source of developing new bioactive substances. Matsui et al.  treated activity .Plants have always been an important source of drug development due to their wide distribution, rich resources, effectiveness, and high safety. Moreover, plant secondary metabolites also can be widely used in pharmaceuticals and other fields. Many researchers have screened α-glucosidase inhibitors from plants and they are a rich source of α-glucosidase inhibitory peptides ,78,79.Luffa cylindrical (L.) M. Roem seed, and Ginkgo biloba seed [50 values of 237.43 ± 0.52 μmol/Lol/L, 182.05 ± 0.74 μmol/Lol/L, and 165.29 ± 0.74 μmol/Lol/L [Luffa cylindrical (L.) M. Roem seed, the alkaline protease hydrolysate showed the strongest inhibition of α-glucoside, followed by tryptic hydrolysate, with concentration-dependent inhibition of α-glucosidase (IC50 of 0.48–0.80 mg/mL) [Ginkgo biloba seed was hydrolyzed using alkaline protease and three new peptides with α-glucosidase inhibitory activity were screened: LSMSFPPF, VPKIPPP, and MPGPPSD. LSMSFPPF showed the strongest inhibitory activity (IC50 of 454.33 ± 32.45 μmol/Lol/L), followed by MPGPPSD (IC50 of 943.82 ± 73.10 μmol/L) and VPKIPPP (IC50 of 1446.81 ± 66.98 μmol/Lol/L) [α-Glucosidase inhibitory peptides from various protein-rich plant hydrolysates, such as grains, legumes, and seeds, have been extensively studied. Enzymatic hydrolysis increased the α-glucosidase inhibitory activity of protein hydrolysates . Differeoba seed ,53,85. Fl/Lol/L) . The sub50 of 0.27 mg/mL) showed the highest inhibitory activity corresponding to MW < 5 kDa grade fractions and a yield of 76.08% [50 of 20.4 μmol/L) and EAK (IC50 of 520.2 μmol/L) were obtained, the inhibitory effect of peptides on α-glucosidase is mainly due to the formation of five strong hydrogen bonds between GSR and His674, Asp518, Arg600, Asp616, and Asp282 in α-glucosidase; four hydrogen bonds were formed between EAK and residues Asp282, Asp518, and Asp616. Asp residues are import targets to inhibit the activity of α-glucosidase [Salvia hispanica) hydrolysis, rice bran proteins, and black sesame cake also showed that low molecular weight peptides were more likely to react with α-glucosidase inhibitors [The candidate peptides were further screened based on molecular weight, amino acid composition, and binding energy to α-glucosidase. Low molecular weight peptides have better stability and higher bioavailability, resulting in better biological function in vivo ,88,89. Df 76.08% . Two tricosidase . In the cosidase . The subcosidase . Similarhibitors ,92,93. Mhibitors . This ph50 of 109.48 μmol/L) containing three hydrophobic residues showed strong inhibitory activity against α-glucosidase. In contrast, at 250 μmol/L, peptides DKDPYPK (22.16 ± 0.61%) and GEHGSDGNV (30.84 ± 0.69%) showed lower inhibition than IQEGGLT (55.85 ± 0.26%), probably due to their higher hydrophilicity [50 values of 10.90 mg/mL and 9.00 mg/m. In addition, three novel α-glucosidase inhibitory peptides were isolated from Paeonia ostii ‘Feng Dan’ seed protein: YFFM, FFFM, and YYFM [According to previous investigations, the peptides with strong α-glucosidase inhibitory activity are short peptides with relative molecular weights less than 1 kDa; this is because lower-molecular-weight peptides can enter the active site of α-glucosidase and bind to it. . Howeverhilicity . Quinoa hilicity . Ujiroghhilicity  identifiand YYFM . The amiand YYFM . Accordiand YYFM . Both raand YYFM . Among tand YYFM . These rGypsophila oldhamiana is also involved in leucine and proline [C-terminal arginine had a positive effect on the α-glucosidase inhibitory activity. C-terminal arginine could improve the stability of peptide–enzyme binding, which ensures the strong binding of peptide and enzyme key active amino acid residues. LDLQR (IC50 = 8.59 mM), AGGFR (IC50 = 8.66 mM), LDNFR (IC50 = 9.21 mM) in wheat germ peptides [50 = 134.2 μg/mL) in Spirulina platensis [Juglans mandshurica Maxim.)-derived peptide LPLLR [C-terminal. The analysis of the structure–activity relationship showed that C-terminal arginine had a positive effect on α-glucosidase peptide inhibitory activity and could improve the stability of peptide–enzyme binding, ensure the strong binding of peptide to the key active amino acid residues of enzyme, and promote the α-glucosidase inhibitory activity.For the different amino acid composition of peptides, leucine and valine can participate in muscle repair and blood glucose control; proline can improve the hypoglycemic activity of peptide . The pep proline . Thus, p proline . The anapeptides , LRSELAAlatensis  and, walde LPLLR  showed ePhaseolus vulgaris L.) proteins had a higher α-glucosidase inhibitory potential than acarbose. Black soybean peptides inhibit α-glucosidase through hydrogen bonding, polarity, and hydrophobicity. The main binding sites are Asp34, Thr83, and Asn32 [Cicerarietinum L.) protein hydrolyzates, FGKG showed optimal inhibition of α-glucosidase [Camellia seed cake through enzymatic hydrolysis. The MS/MS spectra and structures of LLVLYYEY and LLLLPSYSEF showed high α-glucosidase inhibitory activity. The binding energies predicted by LLVLYYEY(IC50 = 0.33 mM) and LLLLPSYSEF(IC50 = 1.11 mM) were −9.36 and −9.06 kcal/mol, which were lower than −6 kcal/mol [The binding energy of plant-derived peptides to α-glucosidase can be predicted by docking. The lower the binding energy required for peptides to bind to α-glucosidase, the easier it is to inhibit the activity of α-glucosidase. Four peptides FYNPAAGR, FFVPPSQQ, PGVLPVAS, and FSYNPQAG were screened from the hydrolysates of hot-pressed peanut meal. Molecular docking indicates that peptides can occupy the active pocket of α-glucosidase through hydrogen bonding, hydrophobic interaction, salt bridges, and π stacking, thus preventing α-glucosidase from forming a complex with substrates. Among these four peptides, PGVLPVAS had the lowest binding energy to α-glucoside, followed by FYNPAAGR, FFVPPSQQ, and FSYNPQAG . Therefond Asn32 . Among tcosidase . Since Fcosidase . Potentikcal/mol . Lineweakcal/mol . Ibrahimkcal/mol  reportedAs mankind’s knowledge of the world deepens, the vast resources contained in microorganisms are being understood. For peptides, microbiota is a high-quality source that is gradually being exploited by mankind. Due to the short life cycle, fast growth, reproduction, and low culture cost of microorganisms, more and more scholars are focusing on obtaining α-glucosidase inhibitory peptides from microorganism.Aspergillus oryzae N159-1. The intracellular concentration of this inhibitor reached its highest when the fungus was cultured in trypsin soybean broth medium at 27 °C for 5 days and the IC50 value of 3.1 mg/mL for α-glucosidase inhibition. Another study showed an endophytic fungus isolated from the Acacia nnilotica was identified as Aspergillus awamori, a protein with a molecular mass of about 22 kDa [50 value of 5.625 μg/mL. In addition, three cyclic dipeptides, namely L-Pro-L-Leu, L-Pro-L-Val, and L-Pro-L-Phe, were isolated from Pseudomonas fluorescein IB-MR-66e, which had important inhibitory activities against α-glucosidase [Kang et al.  found α-t 22 kDa . The purcosidase .C-terminus [C-terminal end improves the stability of the peptide–enzyme binding, ensures strong binding of peptides to key active amino acid residues of the enzyme, and promotes increased inhibitory activity [Many studies have shown that naturally active peptides could treat type 2 diabetes by lowering blood sugar, but screening for them is a time-consuming process ,107. To terminus ; (3) Theactivity ; (4) ThePelodiscus sinensis) egg to obtain potential anti-diabetic peptides. Furthermore, three oligopeptides, HNKPEVEVR, ARDASVLK, and SGTLLHK, were synthesized, which had strong inhibitory effects on α-glucosidase activity . Li et al. [50 value of 109.65 μmol/L was identified from moringa seed protein hydrolysate. The binding energy of MoHpP-2 to α-glucosidase was −6.3 kcal−1, indicating that MoHpP-2 has a good binding effect. Molecular docking indicated that MoHpP-2 interacted with α-glucosidase protein mainly through hydrogen bonding and hydrophobic force [Hydrogen bond and hydrophobic interaction play an important role in α-glucosidase inhibition. Qiu et al.  used papi et al.  investigi et al. . Moleculi et al. . The detic force . Anotheric force . This inic force . DipeptiGinkgo biloba seed cake. There were 12 effector sites of van der Waals force between LSMSFPPF and α-glucosidase [The presence of van der Waals forces also affects the activity of α-glucosidase. Three new peptides including LSMSFPPF, VPKIPPPHE, and MPGPPS which had α-glucosidase inhibitory activity were selected from the protein isolates of cosidase . For thecosidase .For the α-glucosidase inhibitory peptide, it can form hydrogen bonds with the active site of the α-glucosidase which makes the binding more stable. At the same time, the inhibitory peptide interacts with the hydrophobic part of the enzyme to enhance the affinity between the inhibitory peptide and enzyme; the stability of the binding site has also been enhanced. This ultimately prevents the enzyme from binding to oligosaccharides, thereby effectively inhibiting changes in blood glucose. Van der Waals force interactions between α-glucosidase inhibitory peptides and enzymes can affect the binding and dissociation kinetics of inhibitory peptides, thus regulating enzyme activity, and some inhibitory peptides can improve the affinity and selectivity of inhibitory peptides by enhancing van der Waals force interactions with enzymes. The binding sites of the α-glucosidase inhibitory peptides described above are mostly similar. Systemic delivery of functional peptides via the oral route has been a daunting task. Low bioavailability of peptide was due to denaturation in the digestive tract, susceptibility in enzymatic reaction, and poor permeability in the cell membrane . In the Foods not only provide nutrition, but also provide many functional ingredients that are beneficial to health. Food-derived α-glucosidase inhibitory peptides are non-toxic and can inhibit the increase in blood glucose concentration, which shows great potential in the management and treatment of diabetes. By systematically reviewing the research progress of α-glucosidase inhibitory peptides and analyzing the structural characteristics of α-glucosidase inhibitory peptides from different sources, it will be helpful to screen α-glucosidase inhibitory peptides more efficiently. Meanwhile, the discoveries of α-glucosidase inhibitory peptides can be accelerated by bioinformatics analysis. As dietary active peptides, it is also necessary to consider whether they will be degraded by digestive enzymes; thus, increasing the stability and bioavailability of α-glucosidase inhibitory peptides are important issues. Especially, will these bioactive peptides affect the gut microbiota and provide additional mechanisms for lowering blood glucose? These issues require further study. At present, there is still a long way to go for α-glucosidase inhibitory peptides use in the management and treatment of diabetes. Based on the existing research progresses, how can we develop α-glucosidase inhibitory peptides with therapeutic value? How can we cut the cost of preparing α-glucosidase inhibitory peptides? Can mixture peptides inhibiting α-glucosidase activity be used to lower blood glucose? These are the key issues to be solved in the future. In particular, the research on clinical trials needs to be strengthened and only obvious effect in population intervention experiments can be applied to food, health products, and drug development in the future.


Microplastic pollution has emerged as a global environmental concern, exhibiting wide distribution within marine ecosystems, including the Arctic Ocean. Limited Arctic microplastic data exist from beached plastics, seabed sediments, floating plastics, and sea ice. However, no studies have examined microplastics in the sea ice of the Canadian Arctic Archipelago and Tallurutiup Imanga National Marine Conservation Area, and few have explored Arctic marginal seas’ water column. The majority of the microplastic data originates from the Eurasian Arctic, with limited data available from other regions of the Arctic Ocean. This study presents data from two distinct campaigns in the Canadian Arctic Archipelago and Western Arctic marginal seas in 2019 and 2020. These campaigns involved sampling from different regions and matrices, making direct comparisons inappropriate. The study’s primary objective is to provide insights into the spatial and vertical distribution of microplastics. The results reveal elevated microplastic concentrations within the upper 50 m of the water column and significant accumulation in the sea ice, providing evidence to support the designation of sea ice as a microplastic sink. Surface seawater exhibits a gradient of microplastic counts, decreasing from the Chukchi Sea towards the Beaufort Sea. Polyvinyl chloride polymer (~60%) dominated microplastic composition in both sea ice and seawater. This study highlights the need for further investigations in this region to enhance our understanding of microplastic sources, distribution, and transport. Secondat review . Severalt review ,9,10). DMicroplastics have been found in the sediment, sea surface, and sea ice of the Arctic Ocean ,12,13,14As a result, the transport processes that govern the fate and ecological impact of microplastics remain largely unknown. Consequently, it is essential to investigate the distribution and deposition of microplastics in environmental compartments to gain a deeper understanding of these transport mechanisms and develop predictive models for identifying hotspots, assessing ecological risks, and implementing mitigation strategies.Here, we present the MP data obtained from two Arctic campaigns: the Northwest Passage Project, which took place in July and August 2019 across the Canadian Arctic Archipelago (CAA) aboard the Swedish RVIB Oden, and the SKQ0202014S Cruise, conducted in October and November 2020 on the United States RV Sikuliaq. These two campaigns involved the collection of samples from distinct regions and matrices, and therefore, they are not intended for direct comparison. Our study aims to provide valuable microplastics data from understudied regions where existing data are limited. While born from opportunistic samplings, our research was developed with the precise goal of addressing critical knowledge gaps in understanding microplastic distribution and accumulation in these specific locations. By analyzing carefully selected samples from both sea ice and seawater environments, we seek to explore potential differences in microplastic dynamics and uncover unique insights into pollution sources and environmental characteristics. Through our study, we aim to contribute scientifically relevant and meaningful data to address the broader issue of microplastic pollution in regions where information is scarce. As highlighted in recent literature, e.g., ,23,24,25The study area encompassed the Chukchi and Beaufort Shelves as well as the Canadian Arctic Archipelago (CAA), as illustrated in The significant declines observed in multi-year ice (MYI) in the Canadian Arctic Archipelago (CAA) and the Beaufort Sea are relevant to the aforementioned water mass transports. As mentioned earlier, Pacific water is transported through the Bering Strait into the Chukchi Sea and further into the western Beaufort Sea. The loss of MYI in the Beaufort Sea, which has exceeded that of the north-facing coast of the CAA, indicates a reduction in the presence of thick sea ice along the pathway of Pacific water transport . It is nAll the information and data pertaining to the samples are presented in www.canada.ca/en/environment-climate-change/services/ice-forecasts-observations/publications/interpreting-charts, accessed on 1 September 2021) were utilized. The cores were drilled and collected into black plastic bags for transportation. The samples were rinsed with deionized water (DIW) once onboard and cut using a stainless steel saw into two sections at 20 cm to preserve vertical resolution. In conjunction with sea ice cores, we collected under-ice water samples (1 L) using hand bottles to observe the microplastic concentration beneath the sea ice. After cutting, the sea ice was rinsed again with DIW and stored in multilayer foil bags  until it was melted for further analysis.During the Northwest Passage Project conducted in July and August 2019, a total of five sea ice cores were collected  using a In October–November 2020, aboard the research vessel Sikuliaq, we collected a total of 17 water samples see . These sBy filtering a substantial volume of water through the 15-micron mesh sieve at the point of collection, we aimed to maximize the chances of capturing microplastics and obtaining representative data for our study. This approach allowed us to assess the microplastic content accurately and gain valuable insights into their distribution and abundance in the sampled environment.The collection of samples occurred during various transects conducted throughout the cruise. The average water depth for sampling was approximately 85 m, with the maximum depth reaching 500 m. The majority of the samples were acquired from Distributed Biological Observatory (DBO) stations, which were strategically selected for this study, as it marked the inaugural instance of microplastic collection/sampling during a DBO cruise. Specifically, we prioritized sampling water layers situated above a depth of 50 m, which accounted for 11 out of the 17 total samples collected.The derived particle numbers per liter (MP.L) of melted ice and per liter of seawater were calculated from the number of particles (n.MP) and the volume fraction (Volume.L) of the sample. Particle numbers obtained from blank samples (control) were subtracted from the particle count . Figure The sea ice samples were melted inside the foil bags, and upon complete melting, were pre-filtered through a 5-micron sieve and then filtered under vacuum onto glass microfiber (GF/F) filters  on a clean bench on board the vessel. The filtered samples were then stored in the dark at −20 °C for subsequent analysis after the cruise. Due to capacity constraints, we only performed subsetting of the core into horizons starting from core 3. Subsequently, we decided to establish a vertical resolution to assess the vertical distribution of microplastics (MP), which is a well-established approach utilized in previous studies.Once on land, the filters were examined using a Zeiss stereoscope to count and characterize the plastic particles at the University of Rhode Island (URI) Graduate School of Oceanography (GSO). Furthermore, the filters were subjected to polymer composition analysis using a Raman WITec alpha 300 R microscope at the URI Rhode Island Consortium of Nanoscience and Nanotechnology (RIN2). A comprehensive description of the detailed procedure can be found in the The under-ice seawater collected during the NPP cruise was filtered using a 5-micron sieve and subsequently examined onboard using stereoscopy see  to avoidTo ensure accurate and reliable analysis of microplastics throughout the process, stringent quality control measures were implemented to prevent contamination. To exclude sources of synthetic polymers at each sampling stage, we ensured that personnel wore non-fibrous clothing. The lab had separate spaces for sample preparation, processing, and analysis. These areas were regularly cleaned and maintained to minimize the presence of microplastics and prevent cross-contamination. All glassware and other materials were thoroughly washed and rinsed with deionized water and 70% ethanol, to prevent particles from adhering to the surfaces.The coring system was constructed using fiberglass with an aluminum head, whereas seawater samples were collected using plastic bottles (during NPP) and Niskin bottles (during SKQ0202014S).To assess external contamination in plastic bottles, a blank sample was conducted during NPP. For this, one bottle was filled with deionized water, and the blank sample was processed alongside the real samples obtained from the environment. This procedure was performed once, considering resource and logistical constraints. The results of the blank sample showed no contamination. Although it would have been ideal to conduct the field blank concurrently with each sampling collection, the confidence in the reliability of the data was upheld due to the results obtained.During SKQ0202014S our capacity was limited, and we could not perform field blanks. Following SKQ0202014S seawater collection, the samples were filtered using a 15-μm metal sieve, which had been pre-rinsed with deionized water and 70% ethanol. To minimize contamination risk, the sieve was covered with aluminum foil, and plastic particles were rinsed directly into clean bottles containing 5% formalin. The entire process was carried out on a clean bench to ensure further prevention of contamination.Regular quality control checks such as running blank samples were conducted throughout the analysis process . All datMicroplastics were analyzed using a WITec alpha300 R confocal Raman microscope equipped with a CCD camera, motorized XYZ stage, and 785 nm laser source. Spectra were acquired with the laser power set to 10 mW and an integration time of 1 s × 300 accumulations . The speOnce the Raman spectra were acquired, they were translated into identifiable plastic types see  using thhttps://doi.pangaea.de/10.1594/PANGAEA.937543, accessed on 1 May 2023). These values suggest that the sea ice was most likely multi-year ice (MYI) that originated from the Central Arctic, based on previous studies [The sea ice samples obtained during the Northwest Passage Project exhibited an average salinity of 1.98 ± 1.17  are not statistically significant. Future studies may want to consider analyzing a greater number of cores’ subsections to further explore the distribution.Based on this result, it is suggested that the plastic particles exhibited a tendency to uniformly aggregate throughout the ice core. This is consistent with previous studies conducted on Arctic Sea ice, where plastic concentrations agreed with heterogeneous distribution ,12,13. HAs delineated in Overall, the MP particles occurring in the seawater samples, excluding fibers, showed an average of 1.9 MP/L, with a maximum of 11.7 MP/L in surface waters. The MP per liter of seawater were greater at the Distributed Biological Observatory (DBO) stations where water was collected in the Chukchi Sea , and acrConsidering the different bathymetry of the two sites, we categorized the samples based on their depth into three distinct groups: surface samples (0–20 m), subsurface samples (20–50 m), and deeper samples (50 m to the bottom). Surface samples demonstrated an average microplastic concentration of 3.3 ± 4 MP/L, subsurface samples displayed an average concentration of 1.7 ± 1.5 MP/L, and deeper samples exhibited an average concentration of 0.75 ± 1 MP/L . These oFibers and fragments were the predominant plastic shape types observed at all stations. Nevertheless, due to the absence of a blank control during sampling, these results may have been subject to bias. Additionally, beads particles were identified in 35% of the analyzed samples. Notably, the samples collected at station DBO3, located near the Bering Strait along the Alaskan Coastal Current, exhibited the highest concentrations of plastic particles for each shape type . ConversOverall, polyvinyl chloride (PVC) emerged as the most prevalent polymer across the distinct compartments .The polymer composition exhibited low variability across the different compartments analyzed. In the sea ice samples, a total of seven distinct polymer species were identified, while six polymers were detected within the seawater samples. However, the number of samples analyzed in seawater versus sea ice could have biased the results. Interestingly, the low-density polymers PAA and PVP were not found in sea ice samples, whereas high-density polymers, such as PPS, PET, and PBT were not detected in the seawater samples . This reThe concentration of microplastics observed in the sea ice of the Canadian Arctic Archipelago (CAA) in the summer 2019 was found to be consistent with a more recent study conducted in the Central Arctic region .The studies conducted by Kanhai et al. (2020) , Peeken The introduction of microplastics into our sea ice samples is hypothesized to originate from Pacific waters entering the Arctic Ocean through the Bering Strait, as suggested by Peeken et al. (2018) . The ChuTo comprehensively understand the dynamics of microplastics within sea ice, it would be beneficial to gather microplastic data from multiple seasons when sea ice is formed. This would allow for a more comprehensive assessment of the quantity of microplastics that become frozen within first-year ice, as well as the amount released during the melting process.Our study was able to provide more observations in the Beaufort Sea for microplastic particle counts focusing on the seasonal sampling period when historically, microplastics in seawater have been observed, as exemplified in . It is oGiven these variations in the sampling methods, it is crucial to express microplastic concentrations in appropriate units that account for the characteristics of the respective sampling tools. As a result, the studies cited in the present work have employed different units for microplastic concentration, reflecting the diversity in sampling approaches and their associated volumes. Consequently, a direct comparison of the magnitude of microplastic concentrations across these studies is not feasible. Furthermore, we were unable to perform blank control runs during the sampling procedure. Consequently, we acknowledge the potential for bias in the recorded fiber content within our samples. Nevertheless, when comparing data that includes fibers to data that excludes them, our analysis shows that the overall microplastic concentration remained spatially consistent. Notably, the presence of fibers in the samples, particularly in sample DBO3 refer to , resulteIt is crucial to acknowledge that, in this study, we have categorized all fibers as external contaminants. However, we are aware that fibers constitute the most prevalent type of microplastics found in the environment , while six types were found in the waters of the Chukchi and Beaufort Seas. Among these, fibers and fragments of polyvinyl chloride were the most abundant microplastic types, comprising approximately 60% of the microplastics found in both sea ice cores and seawater samples.Overall, this study contributes to our understanding of microplastic distribution and composition in the western Arctic Ocean, highlighting the importance of considering both sea ice and seawater compartments. Subsequent research endeavors should focus on amalgamating the dataset by concurrently collecting samples from distinct sea ice, the seawater column, and sediment within identical locations and time frames.


Cephalomedullary nailing of unstable intertrochanteric fractures has been established as a fruitful surgical approach with relatively limited complications. Anatomic fracture reduction and proper implant positioning are vital to attaining a favorable long-term surgical outcome. Appropriate intraoperative fracture compression augments stability and invigorates healing. The amount of compression permitted by cephalomedullary nails cannot always adequately reduce large fragment gaps. This paper presents a novel technical trick of double compression of the fracture site, in order to achieve the essential extra compression and reduction when required, thus decreasing the risk of postoperative implant cut-out. The technique was used in 14 out of 277 peritrochanteric fractures treated with cephalomedullary nailing in our trauma center for 12 months, with satisfactory outcomes regarding both fracture site union and postoperative functional capacity. Peritrochanteric fracture treatment aims to attain a stable fracture fixation for the patients to return to their pre-fracture activities as rapidly as possible. Over the past decades, outcomes have confoundedly improved with operative treatment . HoweverIt is paramount to practice diligent operative techniques to achieve anatomic fracture reduction because proper implant placement cannot be accomplished prior to an anatomic reduction . TAD andIn many cases, a large fracture gap (greater than 10 mm) cannot be satisfactorily reduced with the amount of compression permitted by dual lag-screw cephalomedullary nailing systems. When the fracture gap cannot be eliminated, and complete compression of the fracture cannot be achieved, the risk of lag screw cut-out and osteosynthesis failure is high  and 2.To avoid these complications, we recommend a technical trick of double compression (two-stage compression) of the fracture site to attain gradually more than 13 mm of compression and always in control by the surgeon. When utilizing a dual lag-screw cephalomedullary nail for fixation of intertrochanteric fractures with large fracture gaps, complete compression of the fracture site and absolute medial cortex reduction can be safely achieved with our trick. This offers an utterly stable osteosynthesis and facilitates the postoperative management of challenging unstable peritrochanteric fractures, allowing immediate full weight-bearing, while this is not feasible with the conventional techniques as sufficient medial wall compression cannot be accomplished.To our knowledge, there is no other surgical technique described in the existing literature that resolves the problem of remaining fracture gap after implementing the full compression offered by the cephalomedullary nailing systems.In our trauma center, 277 patients sustaining an intertrochanteric fracture were admitted and operated on using a dual lag-screw cephalomedullary nailing system  during a 12-month length of time. During the operation, a fracture gap greater than 13 mm was present in 14 cases, in which the undermentioned double compression technique was applied. The technique is not included in the company’s manual for Trigen InterTAN, Smith & Nephew, UK (10 + 3 mm maximum compression is depicted).The technique is described as follows:After executing the anatomical reduction of the fracture and a large fracture gap is observed, we proceed with the standardized steps of nail insertion. We confirm the guide pin position in the anteroposterior (AP) and lateral planes. The guide pin should be at the femoral head’s center in both views, with a tip-apex distance (TAD) of less than 25 mm . At thisProceed with the standardized step of drilling for interlocking compression-screw insertion and then insert the antirotation blade . Carry on with the established procedure for lag screw drilling and insertion. Under fluoroscopy imaging, advance the lag screw manually to the 0 mm mark on the lag screwdriver and then to the 10 mm mark. The mark on the lag screwdriver represents the system’s available amount (10 mm maximum) of compression, which is the gap reduction length offered by the system controlling the procedure.Remove the anti-rotation bar and attach the interlocking compression screw packaged with the lag screw. Advance the compression screw, and after releasing traction, compression is achieved by advancing the compression screw assembly until the 0 mm mark on the lag screwdriver is visible (first compression).It is recommended to halt the compression when the 0 mm mark appears. However, extra compression (2–3 mm) may be accomplished by advancing the compression screw until the red mark on the lag screwdriver is discernible . Until this point, the common surgical procedure is performed, and at the c-arm’s monitor, we descry a remaining fracture gap (5 mm). If calculated correctly, there is space between the subchondral area of the femoral head and the lag screw to advance (5 mm) . The lagAt this point, we proceed with the steps for the second compression. Remove the compression screw and reinsert the anti-rotation bar in its position. Under constant fluoroscopy-imaging assistance, advance the lag screw with the proper screwdriver at the desired depth . Do not advance the lag screw without the anti-rotation blade in place.At the lag-screw’s screwdriver, notice the mark of the extra depth advanced by the lag screw (5 mm). Remove the anti-rotation bar and reinstall the compression screw. Then, commence the second compression of the interlocking lag screw, the extent of which is determined by the amount of resistance received from the fracture gap compression and the fluoroscopic imaging.Keep on with fracture site compression until the optimal outcome is evident in both views .Second fracture compression is acquired. Proceed with the standardized steps for locking the pre-loaded set screw and the nail distally. Medial wall compression and lag screw locking provide stability to the fracture site and the osteosynthesis, promoting fracture healing and immediate full weight-bearing.The double compression technique was applied to all 14 cases of peritrochanteric fracture with a large gap (greater than 13 mm) with a 100% success rate. No intraoperative and postoperative complications were observed. The technique was completely controlled by the surgeon during the operation. It was effortlessly repeated in all cases, without the learning curve arduousness. There was a positive reduction and compression of the fracture site in all cases. We did not detect any lag-screw cut-out during the first year of follow-up. Full weight-bearing was achieved immediately postoperatively in all cases. At the 1-year follow-up, a fracture union was observed in the hip X-rays of all 14 patients, which were pain-free VAS 0.6 out of 10 and presented with a near-perfect postoperative Harris Hip Score .Particular attention should be paid to fracture site reduction and lag screw positioning to diminish mechanical complications such as lag screw cut-out, which aggravate morbidity and mortality associated with proximal femur fractures . StudiesDuring fracture reduction, cortical support should be ensured for both AP and lateral views. It is essential to be vigilant regarding the positive cortical support in the lateral view . SuperioPoor reduction and larger calcar fracture gapping in the AP and lateral views are risk factors leading to alterations in anteromedial cortical support . MechaniMeta-analysis data suggest that integrated twin compression screw cephalomedullary nails are clinically more efficacious compared to single screw derotation cephalomedullary nails, resulting in fewer postoperative complications, revisions, and reduced pain scores . On the At this point, we add an extra benefit in the use of integrated twin compression screw cephalomedullary nails, which is the capability of a second (double) compression of the fracture site intraoperatively. This offers unstable fractures with a large gap, and a proper and stable healing environment. It is an undemanding and repeatable procedure.Absolute reduction of the fracture gap and intraoperative compression of the fracture site is requisite to attain stable and safe osteosynthesis. Immediate weight-bearing of the fracture can be achieved, avoiding complications such as lag screw cut-out. The technical note of double compression presented by the authors is a safe and repeatable procedure. It can provide the crucial extra reduction and compression of the fracture gap when necessary, constantly controlled by the surgeon, exceeding the features of integrated dual lag-screw cephalomedullary nails.


OF1-ATP synthase/F1-ATPase imprint a unique record of molecular events during the catalytic cycle of ATP synthesis/hydrolysis. This work presents a new theory of oxygen exchange and tests it on oxygen exchange data recorded on ATP hydrolysis by mitochondrial F1-ATPase (MF1). The apparent rate constant of oxygen exchange governing the intermediate Pi–HOH exchange accompanying ATP hydrolysis is determined by kinetic analysis over a ~50,000-fold range of substrate ATP concentration (0.1–5000 μM) and a corresponding ~200-fold range of reaction velocity (3.5–650 [moles of Pi/{moles of F1-ATPase}−1 s−1]). Isotopomer distributions of [18O]Pi species containing 0, 1, 2, and 3 labeled oxygen atoms predicted by the theory have been quantified and shown to be in perfect agreement with the experimental distributions over the entire range of medium ATP concentrations without employing adjustable parameters. A novel molecular mechanism of steady-state multisite ATP hydrolysis by the F1-ATPase has been proposed. Our results show that steady-state ATP hydrolysis by F1-ATPase occurs with all three sites occupied by Mg-nucleotide. The various implications arising from models of energy coupling in ATP synthesis/hydrolysis by the ATP synthase/F1-ATPase have been discussed. Current models of ATP hydrolysis by F1-ATPase, including those postulated from single-molecule data, are shown to be effectively bisite models that contradict the data. The trisite catalysis formulated by Nath’s torsional mechanism of energy transduction and ATP synthesis/hydrolysis since its first appearance 25 years ago is shown to be in better accord with the experimental record. The total biochemical information on ATP hydrolysis is integrated into a consistent model by the torsional mechanism of ATP synthesis/hydrolysis and shown to elucidate the elementary chemical and mechanical events within the black box of enzyme catalysis in energy metabolism by F1-ATPase. Oxygen exchange reactions occurring at β-catalytic sites of the F OF1-ATP synthase/F1-ATPase has been studied extensively. Structural studies using X-ray crystallography provided the first snapshots of this vital enzyme in animal mitochondria at high resolution and glimpses of its interacting parts ATP in the Tris-acetate buffer  at 30 °C were made. F1-ATPase of 5–6 mg mL−1 concentration was diluted 10-fold, and 5 µL was added to 50 µL buffer at 30 °C. The reaction was initiated by adding 0.45 mL of reaction mixture to the ATPase. The reaction was quenched by the addition of 0.5 mL of cold chloroform after approximately 100 nmol Pi had been produced.Oxygen exchange experiments were performed at pH 7.4 and 30 °C in 30 mM Tris-acetate and 30 mM potassium acetate buffer. The ATPase reactions were started by the addition of varying volumes of F1-ATPase was isolated by taking aliquots of quenched reaction mixtures adjusted to 1 mL with H2O. Then, 0.5 mL phenol was added and centrifuged to remove the protein with the phenol. The phenol layer was washed with 1 mL of H2O which was added to the original aqueous layer. The phenol present in the combined aqueous layers was extracted into 2 mL of 1:1 isobutenol:benzene by volume. Molybdate was added, the phosphomolybdate extracted with isobutenol:benzene , and the Pi was extracted into an alkaline H2O solution. The Pi was separated from the molybdate and converted to H3PO4 using column chromatography techniques Pi species by GC-MS .The Pi formed by the Fchniques . The H3P3PO4 were derivatized with diazoethane in ethane , [18O2], [18O1], and [18O0] species in Pi for a specified initial distribution, A0 of 18O in the γ-PO3 group of substrate ATP, with 18O with 3, 2, 1, and 0 labels that progressively change with time due to oxygen exchange. The oxygen exchange reactions taking place within a single enzyme catalytic site during ATP hydrolysis are represented by the overall kinetic scheme of Following several authors ,79,80, aPoisson process if Computer simulation of the system with different values of AndThe chemical kinetics of the series reaction system for a population of enzyme molecules (Equation (11)) can be directly written as a set of ordinary differential equations using mass action principles (Equation (12)):Integrating and solving the set of ordinary differential equations (Equation (12)) recursively ,78,79,80Andaverage time between oxygen exchange events is set by a particular experimental variable  despite the exchange events themselves being stochastic, with the exact timing of the events possessing a random nature. The oxygen exchange events are also independent of each other, and the occurrence of one exchange event does not influence the probability of the occurrence of a second exchange event. Moreover, two or more exchange events do not occur simultaneously at a single catalytic site of the enzyme, and the average rate of oxygen exchange events per unit time in the population of enzyme molecules is constant. The similarity in the form of the above chemical kinetics equations with the mathematical equations of a Poisson-type model of the process is useful because the exchange reactions satisfy the requirement that the 1-ATPase. This study attempts to analyze and quantify the overall extent of the intermediate Pi–HOH exchange and predict the resulting Pi isotopomer distributions as a function of time during ATP hydrolysis by mitochondrial F18O/P ratio with changing ATP concentration on a semi-log scale and estimates the average number of 18O water oxygens incorporated into Pi by intermediate Pi–HOH exchange occurring during ATP hydrolysis by the F1-ATPase. At saturating ATP concentrations, 18O in water or the 18O in the γ-phosphoryl group of ATP, depending on where the label is situated.The time scale of the oxygen exchange measurements is determined by the reciprocal of the steady-state velocity during ATP hydrolysis that enables the analysis of the modulation of the fractional extent of oxygen exchange, n itself ,60, or  transferred to each released Pi molecule from the γ-phosphoryl group of ATP upon intermediate Pi–HOH exchange occurring by ligand permutation about the phosphorus center [18O]Pi species containing 0, 1, 2, or 3 18O atoms as a percentage of the total have been compared using Equations (13)–(16) as a function of medium ATP concentration, given the initial distribution of 18O in the γ–PO3 group of ATP shown in trometry . In othes center  is avail18O]Pi distributions at each medium ATP concentration or time point generated a vast amount of data, and we sought a cleaner and short-form way to represent the results. A C++ computer program was written that collated data at each temporal point for [18O]P3, [18O]P2, [18O]P1, and [18O]P0, i.e., with [18O3], [18O2], [18O1], and [18O0] species in the released Pi after oxygen exchange by F1-ATPase  or rise (for [18O]P2 and [18O]P1) is underestimated by the model. Hence we attempted prediction of the oxygen exchange based on the stochastic kinetic theory developed in three sites of oxygen exchange at short times (0–33 ms) corresponding to high substrate ATP concentrations (4.2–5000 μM) and two sites of oxygen exchange at long times (33–266 ms), i.e., at low substrate ATP concentrations (0.11–4.2 μM), at the experimentally-determined essentially constant value of −1 (1-ATPase at every ATP concentration (µM to mM) arises entirely from the activity of the (111) species in a trisite mode of catalysis in which rotation occurs with all three catalytic sites occupied by bound Mg-nucleotide –(16) implement a Poisson-type model for the distribution of various [18O]Pi isotopomer species during ATP hydrolysis, and since these equations are also in terms of The principal equations from our theoretical analysis in 18O of Pi could arise either from an alteration in the rate constant of exchange or from an increase in the time available for exchange. The latter situation would arise due to the differing length of time spent by the Pi/ATP in the β-catalytic site due to a faster/slower turnover of the hydrolytic reaction. For instance, a longer time spent while bound ATP is waiting for rotation of the γ-subunit/conformational change in F1 to take place before activation or before the cleavage chemical step occurs at a catalytic site to form Pi, or a longer time spent while the Pi formed after hydrolysis is waiting for its release from the site etc., will show up as an increased extent of oxygen exchange at a lower ATP concentration.The stochastic kinetic model of the oxygen exchange process (Equations (6) and (13)–(16)) makes no specific assumptions about the mechanism and is therefore independent of the mechanism. These equations characterize the exchange in terms of the product of the apparent rate constant of exchange, 1-ATPase and modification in the value of the rate constant of the exchange by such signal and energy transmission Pi distributions with a single site/route of entry of 18O water , as oppsynthase . Furthereviously ,64,83,84A− + Δμ̃H+) Pi distributions at long times. If site 2 had contributed at long times, we would obtain a non-integer value for the exchange; moreover, if site 2 contains ADP as expected, then it should not mediate any exchange in the first place. By another element of logic, the site that could contribute to exchange at short times (and subsequently not make a contribution) has to be the site (site 2) that engages in the L → O change.Every model of trisite hydrolysis, when looked at in a gross way, postulates for the enzyme as a whole that site 3 (O) changes to site 1 (T), site 1 (T) changes to site 2 (L), and site 2 (L) changes conformation to site 3 (O). Following the conformational change to site 3 (O), the bound nucleotide would be released and, therefore, can no longer participate in the exchange. If two catalytic sites have to contribute equally to exchange at long times by effectively doubling the time of exchange , then thligand displacement as proposed by us ATP is used in a cold chase experiment, 92–94% of the promoter [γ-32P]ATP is hydrolyzed in site 2 (L) within 10 s of incubation time, as detected by counting of 32Pi. This also leads to the key insight that ATP hydrolysis and Pi release  in s1 on the [18O]Pi distributions that further explore the range of intermediate 18O]Pi distributions shown in om three D–F to twom three A–C, resp1-ATPase do not measure the extensive oxygen exchange that occurs at multiple catalytic sites at the same time before, during, and after ATP cleavage. However, the above results are not in conflict with results from the single-molecule observations. An exchange rate of 10.5 per s  in F1 (bisite activation) We additionally need to hydrolyze the bound ATP in site 2 (L)  to ADP.Pi and subsequently the Pi need to move away and be released from L, as formulated by a general theory of biological energy transfer Pi species . The efo 0.6 nm , it rele hexamer .DP-like in Pi isotopomer distributions of The order of release of products during ATP hydrolysis by Freleased   in panel 1 of DP or βDP-like) in E changes to βDP-like (now assigned as L or site 2), βDP-like changes to βTP (now ascribed to be T or site 1), and βTP changes to βE. That is, in the reversed assignment, O → L, L → T, and T → O. However, this is neither in accordance with our cold chase experiments nor with trisite hydrolysis in which O should change to T, T to L, and L to O. It implies that the reversed identity assumed at the beginning of this paragraph is incorrect. Moreover, the reversed identity of the sites is unable to reproduce the configuration of the enzyme in TP in the Leslie–Walker structure   of sites 1, 2, and 3. The bold gray curve uses the Kd values tabulated by Senior and coworkers  range as suggested previously Pi isotopomer species found in our work and its stochastic kinetic analysis.Three catalytic sites contribute to oxygen exchange at short times (high [ATP]) that, however, reduce to two sites mediating intermediate Pi–HOH exchange at long times (low [ATP]), as revealed by the detailed experimental distribution of [1-ATPase.The finding 8 imposes strong constraints on possible molecular mechanisms of ATP hydrolysis by FNone of the existing mechanisms, in their current form, fully explain the experimental observations in 8 and present a solution to the mechanistic conundrum.ligand displacement was proposed in 2008 for bisite activation of the F1-ATPase by ATP binding at a second catalytic site by the torsional mechanism and the unified theory [substitution chemistry) to ADP.Pi, and subsequently unbinding and releasing the Pi from the site, presently offers the only way to resolve the mechanistic conundrum [The concept of d theory , with thonundrum ,113. TPβ in the Leslie–Walker structures [site 2 on the basis of our oxygen exchange data.ructures ,2 (PDBIDprecedes ADP release in the catalytic cycle of steady-state ATP hydrolysis by F1-ATPase.Pi release 1-ATPase that are consistent with the results of the oxygen exchange experiments in this work are ATP binding—0°, ATP bond cleavage—200°, Pi release—200°, and ADP release [240°.The elementary chemical processes and the angular position at which they occur during ATP hydrolysis by the complete F release —240°.1-ATPase performs its function of steady-state Vmax hydrolysis using a trisite mechanism, i.e., by a mode of operation in which rotation and catalysis occur with 3-site filling of β-catalytic sites by the Mg-nucleotides MgATP or MgADP. This finding contradicts bisite models of steady-state catalysis by ATP synthase/F1-ATPase proposed within Boyer’s binding change mechanism [Fechanism  but is fechanism ,33 and hechanism ,92. A quantitative analysis of the intermediate Pi–HOH exchange accompanying ATP hydrolysis by FOF1/F1-ATPase [These results and conclusions need to be taken into account in future work on ATP synthesis/hydrolysis by the F1-ATPase .


The study was to investigate serum total IgE levels and the distribution of specific IgE types in children aged 6–9 years with tic disorder, in order to provide knowledge for diagnosis and treatment of children with tic disorder.Total serum IgE levels were detected by enzyme-linked immunosorbent assay (ELISA). Specific IgE levels in 72 children with tic disorder and normal 31 children were detected by EUROblot, respectively.P < 0.05).The total serum IgE level of children with tic disorder aged 6–9 years was significantly higher than those of children in control group. Specific IgE distribution in tic disorder group was observed increased mainly including inhaled mugwort, dust mite combination 1 (house dust mite/dust mite), mold combination (penicillium point/mycobacteria/Aspergillus fumigatus/streptomyces), cockroaches in Germany respectively, and also food freshwater fish combination 1 , marine fish combination 1 , egg white, and crab, while elevated specific IgE of normal children group was mainly food-based . The significant different specific IgE between two groups was dust mite combination 1 (house dust mite/dust mite) , which should be avoided in clinical diagnosis and daily life. Tic disorder (TD) is a complex, chronic neuropsychiatric disorder predominating in children and adolescents, which is characterized by rapid, involuntary, sudden, repetitive, non-rhythmic, single or multiple muscle motor tics and/or vocal tics. It may be accompanied by one or more comorbidities, such as attention deficit hyperactivity disorder (ADHD), anxiety disorder (AD), depressive disorder (DD), learning difficulties (LD), obsessive compulsive disorder (OCD), sleep disorder (SD), etc. . Its incThe etiology of TD has not yet been fully clarified. Current research results show that its etiology is related to biological factors , mental and psychological factors , etc. . The etiThe study was approved by the review board and Ethics Committee of Chinese People’s Liberation Army General Hospital (S2023-119-01). Three mL venous blood of 72 TD patients aged 6–9 years was collected, 58 males and 14 females, with an average age of 7.4 years (7.4 ± 1.2), all from the Children’s Medical Center of the First Medical Center of Chinese PLA General Hospital from January 1, 2018 to December 31, 2019 outpatients. The diagnostic criteria for TD in the American Diagnostic and Statistical Manual of Mental Disorders 4th Edition (DSM-IV) was used [The enzyme-linked immunosorbent assay  was used to determine serum total IgE levels by EU Medical Diagnostics Total IgE Detection Kit, according to the instructions of suppliers. The EU imprinting method  was used to determine serum specific IgE levels by EU Medical Diagnostics Inhalation and Food Allergen-Specific IgE Antibody Detection Kit (EU Blot). Values ≥ 0.35–0.7 kU/l correspond to RAST class 1, values ≥ 0.7–3.5 kU/l to RAST class 2, values ≥ 3.5–17.5 kU/l to RAST class 3, values ≥ 17.5–50 kU/l to RAST class 4; values ≥ 50–100 kU/l to RAST class 5 and values ≥ 100 kU/l to RAST class 6, respectively [χ2 test. P < 0.05 was considered statistically significant.SPSS22 software was used to analyze the data. The quantitative data of two groups were represented by the median interquartile range M (IQR). The comparison between data of two groups was performed by the Mann-Whitney U test, and the rate comparison was performed by P < 0.001, the difference was statistically significant. It was suggested that the increase of total IgE level may be related with TD disease.The serum total IgE level of 72 TD children aged 6–9 years was higher than that of 31 control children  (22.22%), mugwort (16.67%), mold combination (Penicillium punctate/Branches sp./Aspergillus fumigatus/Alternaria) (12.5%), German cockroach (11.11%), hops (8.33%), cat hair (8.33%), common ragweed (6.94%), house dust (4.17%) ), tree combination 2 (willow/poplar/elm) (4.17%), dog epithelium (0%). Food IgE elevation was observed as freshwater fish combination 1  (8.33%), egg white (6.94%), soybean (6.94%), marine fish combination 1  (6.94%), milk (5.56%), beef (5.56%), crab (5.56%), peanut (2.78%), shrimp (2.78%). The specific IgE elevation in TD group was mainly inhaled IgE elevation. The results are shown in Fig. The inhalation specific IgE elevation of 31 children in normal control group was showed as Artemisia annua (9.68%), mold combination  (9.68%), dust mite combination 1 (house Dust Mite/Dust Mite) (3.22%), German cockroach (3.22%), hops (3.22%), cat hair (3.22%), common ragweed (3.22%), tree Combination 2 (Willow/Poplar/Elm) (3.22%), house dust (0%), dog epithelium (0%). Food-induced increases in IgE were showed as milk (12.9%), soybean (9.68%), egg white (9.68%), peanut (3.22%), crab (3.22%), beef (0%), marine fish combination 1  (0%), Freshwater Fish Combo 1  (0%), Shrimp (0%). The increase of specific IgE in children of control group was mainly food-induced. The results are shown in Fig. χ2 test. Only dust mite allergen was found statistically significant . There were no statistical significance in comparison of mugwort, common ragweed, tree combination 2 (willow/poplar/elm), cat hair, German cockroach, mold combination , hops, chicken egg whites, milk, peanuts, soybeans and crabs between two groups. The results are shown in Fig. The positive rate of specific IgE levels of 72 children aged 6–9 years in TD group and 31 children in control group were tested and compared by In this study, we found that total IgE level of children with tic disorders aged 6–9 was significantly higher than that of normal children (P < 0.05). The specific IgE elevation in TD group was mainly inhaled dust mite combination 1 (house dust mite/dust mite), mugwort, and mold combination . The increase of specific IgE in children of normal group was mainly in milk, egg white and soybean. The comparison of the positive rates of specific IgE between two groups showed that only dust mites had statistical differences, suggesting that dust mites may have a certain significance in the pathogenesis of tic disorders. Whether tic symptoms can be considered as a manifestation of allergic reactions remains to be clarified in further research.At present, there are few studies on children with tic disorder and serum IgE. In recent years, relevant reports found that the etiology of tics and of allergic diseases have certain similarities . Yuce etAt the beginning of 2020, in order to prevent the spread of COVID-19 in China, people began to use masks. The use of masks has changed the impact of inhaled allergens in the environment on children. Using allergen data from January 1, 2018 to December 31, 2019 in this study can more accurately reflect the real situation.Children with tic disorder frequently occur in the age range of 5 to 10 years. The data collected from children aged 6 to 9 years in this study can also better reflect the real situation of the disease.This study only analyzed the IgE levels of children aged 6 to 9 years, and more research needs to be supplemented in the future due to limited data. In conclusion, this study analyzed the serum total IgE levels and specific IgE levels in children aged 6 to 9 years with tic disorder and normal children, and provided some knowledge to clinical research of tic disorders.


As such, it could be used as a new selective inhibitor of α-glucosidase. The selective inhibition mechanism of Quercimeritrin on the two starch-digesting enzymes was further explored, and it was confirmed that Quercimeritrin had a strong binding affinity for α-glucosidase and occupied the binding pocket of α-glucosidase through non-covalent binding. Subsequently, animal experiments demonstrated that Quercimeritrin can effectively control postprandial blood glucose in vivo, with the same inhibitory effect as acarbose but without side effects. Our results, therefore, provide insights into how flavone aglycones can be used to effectively control the rate of digestion to improve postprandial blood glucose levels.In this study, 12 flavonoid glycosides were selected based on virtual screening and the literature, and Quercimeritrin was selected as the best selective inhibitor of α-glucosidase through in vitro enzyme activity inhibition experiments. Its IC In the treatment of obesity and diabetes, the control of postprandial blood glucose has attracted widespread attention, given the close link between postprandial blood glucose and diabetic complications . The conDuring starch digestion, α-amylase cleaves starch molecules into small maltose oligosaccharides, whereas α-glucosidase digests α-amylase products into glucose as the final digestive product . To solvAt present, some compounds with selective inhibitory activity toward α-glucosidase have been reported (such as apigenin and quercetin), but the obtained compounds generally have a weak inhibitory effect on α-glucosidase selection ,11. FlavTherefore, we adopted virtual docking technology and combined it with previous studies to screen out flavonoid glycosides with inhibitory potential. Through experimental screening, we expected to find the best selective inhibitor of α-glucosidase. Exploring the structural characteristics of α-glucosidase selective inhibitors and the inhibitory mechanism of selective inhibition can guide the search for more extensive α-glucosidase selective inhibitors. Our findings provide insights into how flavonoid glycosides can be applied to eliminate existing inhibitor side effects and effectively control postprandial blood sugar.Saccharomyces cerevisiae and α-amylase  isolated from porcine pancreas were purchased from Sigma-Aldrich Co. . The other reagents used in this experiment are analytically pure reagents purchased from Sigma-Aldrich Co.  unless specified otherwise.Isovitexin, Trifolin, Avicularin, Apigetrin, Quercetagitrin, Epicatechin gallate, Catechin gallate, Quercimeritrin, Quercituron, Quercitrin, Hyperoside, and Oroxin A were obtained from Purify Inc. , and the α-glucosidase  isolated from Autodock Vina was used to conduct virtual screening of the self-built flavonoid glycosides’ library.Additionally, 2QMJ and 1CXW were selected from the protein database as the crystal structures for α-glucosidase and α-amylase docking. The scoring results were obtained by docking the compounds with α-glucosidase and α-amylase, respectively, and the compounds were sorted and selected.p-nitrophenyl-d-glucopyranoside (pNGP) were produced. All test chemicals, including the standard drug acarbose, were dissolved in DMSO to form a 10 mM mother liquor. Gradient dilution with a phosphate-buffered solution was used to create sample solutions of various concentrations. First, different concentrations of compound (10 μL), an enzyme solution (40 μL), and potassium phosphate buffer (100 μL) were pre-incubated in 96-well plates at 37 °C for 10 min. Then, 50 µL of the substrate  was added to each microwell, and incubated at 37 °C for 20 min, and the change in enzyme activity was detected by measuring the absorbance at 405 nm. Acarbose and DMSO were utilized as standard and control inhibitors, respectively.The in vitro α-glucosidase activity assay was determined using spectrophotometry, as previously reported, with only minor modifications . In phosThe enzymatic inhibitory activity of the tested compounds was calculated using the following formula:50 values of the tested compounds were calculated using nonlinear fitting (logit method).The ICd-maltotrioside (G3-CNP) were produced. All test chemicals, including the standard drug acarbose, were dissolved in DMSO to form 10 mM mother liquor. Gradient dilution with a phosphate-buffered solution was used to create sample solutions of various concentrations. First, different concentrations of compound (10 μL), an enzyme solution (40 μL), and potassium phosphate buffer (100 μL) were pre-incubated in 96-well plates at 37 °C for 10 min. Then, 50 µL of the substrate  was added to each microwell and incubated at 37 °C for 20 min, and the change in enzyme activity was detected by measuring the absorbance at 405 nm. Acarbose and DMSO were utilized as standard and control inhibitors, respectively.The in vitro α-glucosidase activity assay was determined using spectrophotometry, as previously reported, with only minor modifications . A totalThe enzymatic inhibitory activity of the tested compounds was calculated using the following formula:50 values of the tested compounds were calculated using nonlinear fitting (logit method).The ICVmax) and Michaelis–Menten constant (Km) values  is the concentrations of the substrate and inhibitor.To further investigate the inhibitory kinetics of Quercimeritrin, α-glucosidase and α-amylase activities were determined at different substrate concentrations . The rea) values .(1)1v=KBased on the previously described techniques, the fluorescence quenching experiment was somewhat modified . QuercimAt the same time, the changes of microenvironment of fluorophore of tyrosine (Tyr) and tryptophan (Trp) residues were detected. The synchronous fluorescence spectra of 260–320 nm were determined by setting the excitation and emission wavelength intervals to 15 nm and 60 nm, respectively.In this experiment, AutoDock Vina was used for molecular docking. The first step was to prepare the protein crystal structure. Additionally, 2QMJ and 1CXW were selected from the protein database as the crystal structures for α-glucosidase and α-amylase docking, and the protein crystal structure was treated by removing water molecules and adding hydrogen atoms. The second step is small molecule preparation. ChemBiodraw Ultra 14.0  was used to map the three-dimensional structure of quercetin and minimize the energy of the small molecule. In the third step, a docking box is generated for the center, and AutoDock Vina is used for docking. Ten posturing positions were generated during the docking process, and the posturing with the highest Glide score was selected to study the interaction between quercetin, α-glucosidase, and α-amylase.https://cloud.yinfotek.com/ (accessed on 1 September 2023). The force fields of AMBER ff19SB and GAFF  is the concentration of Quercimeritrin as a quenching agent, and Ksv is the Stern–Volmer quenching constant. The quenching mechanism of Quercimeritrin was further investigated to better comprehend how it interacts with the two enzymes . By deteKsv at the three temperatures  shown in Ksv displays the inhibition of the quenching agent on the biofluorescence of the receptor  is the concentration of the Quercimeritrin.In order to further determine the binding constant (aK) and the number of binding sites (n) were calculated  was greater than that with α-amylase , showing that the binding forces of Quercimeritrin and α-amylase were stronger than that of α-amylase [n is approximately equal to 1, indicating that Quercimeritrin has only one binding site for both α-amylase and α-glucosidase. In addition, the fluorescence spectrum of Quercimeritrin and the two enzymes did not exhibit a redshift at the 340 nm emission peak (According to the double logarithmic equation (Equation (3)), the binding constant . The thermodynamic parameters ΔH, ΔS, and ΔG represent enthalpy change, entropy change, and free energy change, respectively. The thermodynamic parameters of Quercimeritrin and the two enzymes at different temperatures were calculated  is calculated using the following formula:As shown in the In general, the affinity of Quercimeritrin for α-glucosidase was much greater than that for α-amylase, which was consistent with the results of the inhibition experiments of the two enzymes in the previous paper, which strongly supported the selective inhibition of the Quercimeritrin for the two digestive enzymes. The high binding affinity of Quercimeritrin to α-glucosidase may be due to the differences in the chemical properties of the activity pockets of the two enzymes .Quercimeritrin was characterized by inhibition kinetics and fluorescence quenching experiments to have a stronger affinity with α-glucosidase than with α-amylase, thus producing a stronger inhibitory effect. Therefore, molecular docking and MD methods were applied to explore further the interaction mechanism of Quercimeritrin with α-glucosidase and compare it with α-amylase to find the difference in the mechanism. First, using molecular modeling, the inhibitory mechanism of Quercimeritrin on the α-glucosidase and α-amylase was investigated. This mechanism is mainly based on steric hindrance, in which inhibitors dock in the active pocket of α-glucosidases and interact with the amino acid residues of the active pocket, resulting in steric hindrance to the binding of other substrates . The calRg), root-mean-square fluctuation (RMSF), and root-mean-square deviation (RMSD) of the protein backbone. All three of those compound systems’ RMSD values fluctuated around 1.2, indicating a comparatively stable system (Rg) refers to how compact a protein structure is. A more stable protein is indicated by a lower value. It was discovered that Quercimeritrin and α-glucosidase complex had a smaller Rg than free α-glucosidase. Because Quercimeritrin formed a more stable system and had a lower Rg value, it was more likely to bind with α-glucosidase and demonstrate substantial inhibitory action  that exhibited the strongest inhibitory activity with the α-glucosidase complex and the free α-glucosidase. The dynamic stability and structural alterations of the complex systems were assessed by looking at the radius of gyration . As shown in In this study, we investigated the inhibitory activities of 12 flavonoid glycosides on α-amylase and α-glucosidase and found that some flavonoid glycosides with specific structures could meet the need for selective inhibition of the two starch-digesting enzymes. The glycoside group at A7 and the OH groups at B5′ and B4′ are conducive to the inhibition of α-glucosidase. TheOH groups at A6, C3, B4′, and B5′ are favorable for the inhibition of α-amylase. In addition, in vitro and in vivo experiments jointly verified that Quercimeritrin can be used as a highly effective selective inhibitor of α-glucosidase. Its selective inhibition mechanism is as follows: Quercimeritrin has a higher affinity for α-glucosidase and interacts with amino acid residues in the active pocket of α-glucosidase through noncovalent bonds (mainly hydrogen bonds), resulting in conformational changes of the enzyme to form an enzyme–Quercimeritrin complex, which plays an inhibitory role. In the future, in addition to developing more effective selective inhibitors, we need to determine how to apply selective inhibitors of α-glucosidase to achieve slow but complete digestion of starch, eliminating the side effects of existing inhibitors while smoothly controlling postprandial blood glucose.


Precise pedicle screw placement of the subaxial cervical spine is difficult. Not every hospital is equipped with a guidance system that can provide effective help. Computed tomography (CT) scanning is almost a routine preoperative examination for cervical spine surgery in all hospitals. Appropriate measurement and analysis of the CT images could assist optimal cervical pedicle screw placement. The purpose of this study is to propose a new and universal method using computed tomography (CT) morphological parameters analysis to assist optimal cervical pedicle screw placement from C3 to C7.A localization system with six parameters was designed based on preoperative CT reconstruction to guide subaxial cervical spine pedicle screw placement. The six parameters were distance from the starting point to the midline [D1], distance from the starting point to the lower edge of the inferior articular process [D2], transverse section angle [TSA], sagittal section angle [SSA], pedicle width [PW], and pedicle height [PH]. The six parameters were analyzed in 53 participants.Combining D1 and D2 could localize the entrance of the pedicle screw, and we concluded that D1 and TSA and D2 and SSA could be a new standard for determination of the transverse and sagittal orientation of the pedicle screw. The six parameters were closely related to the patient’s gender, height, and weight. PH and PW were linearly correlated and could guide selection of the appropriate pedicle screw. SSA was an independent parameter of the relevant vertebral body, and changes in SSA had nothing to do with the curvature or posture of the cervical spine.Understanding and applying the six-parameter localization system are essential for achieving accurate and optimal pedicle screw placement in subaxial cervical spine, regardless of cervical sagittal alignment. The subaxial cervical pedicle screw placement technique has been widely used in clinical practice since it was first described by Abumi  in 1994.Freehand pedicle screw placement mainly depends on the surgeon’s judgment of relevant anatomical landmarks during the operation , 6. ThisAlternatively, a guidance system such as O-arm-based three-dimensional (3D) navigation, 3D model, navigation templates, Doppler donography, robotic guidance system –12, or aThe current study investigated the establishment of a new subaxial cervical pedicle radiographic system utilizing preoperative CT scanning and reconstruction, which could determine the pedicle’s detailed morphology and has the advantages of individualized application, high accuracy, and easy identification.Fifty-three patients  with different cervical spine diseases were enrolled in the study. Baseline characteristics of the participants are shown in Table The axis of the pedicle was defined as the intersection line of the equally divided transverse plane (plane B) and vertical plane (plane A) of the pedicle. The intersection point of the axis on the cortex of the posterior end of the pedicle is the starting point (SP). LP is the lowest point on the lower edge of the inferior articular process on the line where plane A intersects the posterior bone surface. SP was used as the best entry point of the pedicle screw, and the axis of the pedicle was used as the best insertion route.Six parameters were measured based on CT reconstruction derived from each patient Fig. . PedicleAll parameters were measured twice by the same observer on two different occasions and once by another observer to determine intraobserver and interobserver reliability, which was evaluated via intraclass correlation coefficients (ICCs). The reliability of intraobserver and interobserver measurements was consistent if the ICC was between 0.82 and 0.98. Measurements obtained by one observer were used in the analysis.t-test were used to evaluate differences between two groups. Pearson’s correlational coefficient (r) was used to assess correlations between variables. Statistical significance was set at p < 0.05. Correlation coefficients were considered clinically statistically significant if r ≥ 0.3. All data were analyzed via SPSS version 22.0 .Measurement data were expressed as mean ± SD. The chi-square test and matched or unmatched There were no significant differences in any of the six parameters between both sides of the pedicles from the same cervical segment. PW gradually increased from C3 to C7. D1 gradually increased first, reached a maximum at C5, and then gradually decreased. TSA was largest at C4 then decreased gradually from C4 to C7, and TSA at C3 was similar to that at C5. The PHs of C3, C5, and C6 were low, whereas those of C4 and C7 were relatively high. D2 remained similar from C3 to C7. SSA gradually decreased from C3 to C6 and slightly increased at C7  for the SP for placement of the pedicle –22. UnliGiven that most preoperative preparations for pedicle screw placement only focus on the narrowest PW to choose the appropriate width of the pedicle screw, PW is often measured clinically. In the current study there was a linear correlation between PW and the pedicle’s narrowest PH, which can be depicted by an equation. We can incorporate PW—the most common clinical pedicle data—into the equation, obtain PH, and further guide the choice of pedicle screw size. At the same time the sagittal plane of the pedicle has a larger fault tolerance space, which means that the offset of the pedicle screw in the sagittal plane is comparatively safer than that in the transverse plane.After confirming the SP of the pedicle screw by D1 and D2, and choosing the appropriate pedicle screw based on PW and PH, the angle of pedicle screw placement can be guided by TSA and SSA. TSA can be accurately measured via CT scanning, which is also a common and necessary parameter in surgical planning , 23. MorThe correlations between PW and PH, and D1 and SSA can be explained by examining the development of the pedicle. As the spine gradually ossifies after chondrification at the 6th week of embryonic development, three main ossification centers play an important role; one in the centrum, and one each on either side of the vertebral arch. Longitudinal and latitudinal growth of the vertebral body accompany the growth, development, and movement of the whole body. At the same time, the second primary ossification center and the mechanical load should also be considered –26. HoweThe aim of the present study was to facilitate more individualized and accurate pedicle screw placement. With respect to individualization, the first considerations in adults are differences in gender, height, and weight. Pedicles in males and individuals of greater heights and weights were larger than those of females and individuals of smaller heights and weights. This is due to the innate proportional development of individuals , 27, 28.We considered SSA to be another essential parameter that is often overlooked relative to TSA. Routine CT examination is in the supine position, and a change to the prone position during the operation would inevitably lead to data changes with respect to the sagittal alignment of the cervical spine. Therefore, if the sagittal angulation is positioned in the horizontal plane accuracy will be affected , 29, andNotably we do not advocate memorizing the dates of the pedicle’s size and angle. Instead, each pedicle of each patient must be carefully measured before surgery so as to obtain 6 parameters that can be individually and accurately applied to surgery.The current study had some limitations. The size of the sample was relatively small, and it was restricted to Chinese adults. Data measurements are likely to differ in other races and in children, but notably the same measurement methodology could be used. Secondly, the primary aim of the study was to provide an effective aid to assist freehand pedicle screw placement, and it is not appropriate to rely solely on the measurement data to place screws mechanically. The experience of the surgeon and intraoperative feel are still very important. Lastly, although we could precisely fix the SP position and the entrance angle, the system needs convenient devices with which to apply the parameters during surgery. Therefore, we are currently conducting further studies aimed at developing a new locating device based on the system, and broader clinical application of the system.Our localization system based on six parameters derived from CT reconstruction, namely D1, D2, TSA, SSA, PW, and PH, contributes to improved understanding of pedicle anatomy and helps improve the accuracy of cervical spine pedicle screw placement regardless of cervical sagittal alignment. Considering the accuracy, ease of use, and low cost of the system, it is expected to be widely used in clinical practice.