Antibody drugs exert therapeutic effects via a range of mechanisms, including competitive inhibition, allosteric modulation, and immune effector mechanisms. Facilitated dissociation is an additional mechanism where antibody-mediated “disruption” of stable high-affinity macromolecular complexes can potentially enhance therapeutic efficacy. However, this mechanism is not well understood or utilized therapeutically. Here, we investigate and engineer the weak disruptive activity of an existing therapeutic antibody, omalizumab, which targets IgE antibodies to block the allergic response. We develop a yeast display approach to select for and engineer antibody disruptive efficiency and generate potent omalizumab variants that dissociate receptor-bound IgE. We determine a low resolution cryo-EM structure of a transient disruption intermediate containing the IgE-Fc, its partially dissociated receptor and an antibody inhibitor. Our results provide a conceptual framework for engineering disruptive inhibitors for other targets, insights into the failure in clinical trials of the previous high affinity omalizumab HAE variant and anti-IgE antibodies that safely and rapidly disarm allergic effector cells. Facilitated dissociation is a mechanism where antibody-mediated disruption of high-affinity complexes can enhance the therapeutic effects of a drug. Here the authors present a yeast display approach to select and engineer omalizumab variants that dissociate receptor-bound IgE to accelerate its inhibition of the allergic response. Antibodies can exert their therapeutic impact through a variety of mechanisms. Some of these mechanisms rely solely on the binding, inhibition or blocking of their target, while other mechanisms rely on accessory functions mediated by antibody Fc-domains, such as the activation of complement, antibody-dependent cellular cytotoxicity or phagocytosis6. During facilitated dissociation “disruptive” inhibitors engage targets that are sequestered in stable macromolecular complexes, accelerate their dissociation, and then inactivate them, rather than simply blocking interactions between proteins , chronic sinusitis and food allergy11. Most antibody isotypes bind their Fc-receptors weakly and depend on the formation of avid immune complexes for stable interactions, however IgE binds its high-affinity receptor (FcεRI) with a KD of ~100 pM. Mast cells and basophils are therefore coated with IgE antibodies and primed for activation prior to antigen exposure and this priming persists for months12. Therapeutic anti-IgE antibodies  were specifically selected to compete with IgE:FcεRI interactions, and not target IgE receptor complexes. Thus their rate of action is limited by the extremely long half-life of IgE:FcεRI complexes8. Omalizumab and ligelizumab take weeks to achieve maximal response in allergic patients13. Although this limitation has not stopped the application of anti-IgE in the treatment of chronic allergic diseases or gradual allergen desensitization, the therapeutic effect of these agents could be significantly accelerated if they targeted and inactivated existing IgE:FcεRI complexes.We have previously studied the disruptive activities of antibodies and Designed Ankyrin Repeat Proteins (DARPins) directed against IgE antibodies4, despite the ~100-fold higher affinity of ligelizumab for IgE. In contrast a class of DARPin based anti-IgE agents, including the DARPin E2_79, are more effective disruptors of IgE:FcεRI complexes while having similar affinities to omalizumab4. To classify these disruptive agents, we developed the concept of disruptive “efficiency” (ID50/KD), which relates the half-maximal disruptive concentration (ID50) to the affinity for free IgE (KD)4. This disruptive efficiency is effectively a representation of the free energy barrier imposed on the anti-IgE inhibitor for binding to the receptor complex by the steric overlap with the receptor, and improvements in efficiency relate to a decrease in this free energy barrier  and FcεRIα-conjugated polystyrene beads to evaluate disruptive potency (ID50) , and a twofold improvement in ID50 for complex disruption as compared to the Fab  remained unchanged as compared to the more efficient disruptive anti-IgE DARPin E2_79 , potency (ID50), and efficiency, we plotted ID50 vs. KD with lines whose slopes (ID50/KD) correspond to the efficiencies of the original omalizumab Fab and DARPin E2_79 as benchmarks  and variable light (VL) domains. To test this possibility, we expressed two additional constructs, a constrained scFv with a disulfide bond at the VH:VL interface (scFvCC) and a Fab construct with two glycine insertions at the elbow of the Fab heavy and light chains (FabH2L2)17  remained similar  proteins  Fig. . In this50) Fig.  or with 50) Fig. . Incubat50) Fig. 14. The orks Fig. 3. Functi)17 Fig. . ConsistThe omalizumab scFv and H2L2 variants suggest that antibody affinity and disruptive potency could increase proportionally and track linearly along the same efficiency line Fig. . However50/KD) variants. Here we used a biotin-labeled IgE-Fc2–4 as the ligand, a soluble FcεRIα-Ova fusion for the receptor, and a non-FcεRIα binding IgE-Fc3–4 construct (G335C-IgE-Fc3–4) as the inactive ligand mutant , an efficient disruptor (E2_79), and a non-FcεRIα-competing DARPin (E3_53)  Fig. . Each co53) Fig. . Stainin_79 Fig. .Disruptive inhibitors must bind to intact ligand-receptor complexes briefly prior to disruption. Therefore it is possible that during selections with intact complexes, variants that stabilize complexes or bind complexes non-competitively could also be enriched. Therefore a final “co-binding” assay with the ovalbumin-tagged FcεRIα (FcεRIα-Ova) and a FITC labeled anti-Ovalbumin antibody was used to further discriminate non-competitive binders (E3_53) from competitive and disruptive inhibitors  Fig. .19. All selections were conducted on four libraries named for the mutation technique (EP of StEP) and generation (1 or 2)  omalizumab libraries, and then shuffled the mutations from EP library hits using the staggered extension process (StEP) to generate StEP libraries prior to further rounds of selectionion 1 or  The first error-prone library (EP1) progressed during four rounds of selection Fig. , and cloCloned hits and controls were retransformed into fresh yeast, induced, and stained with the disruptive efficiency stain followed by fixation to reduce sample to sample variation caused by dissociation of bound IgE during staining and data acquisition. In this assay Clone 813 and C02 outperform omalizumab scFv, and C02 appears similar to E2_79 Fig. . During 15.Despite selections with intact IgE:FcεRIα complexes, clone 813 bound intact complexes to a similar extent as omalizumab scFv in co-binding assays Fig. . In cont20. When displayed on yeast the HAE scFv exhibits a weaker disruptive efficiency signal than C02 and looks comparable to 813 in terms of efficiency  previously engineered by phage display and taken into clinical trialsncy Fig. . The HAExes Fig. .50, and a small increase in disruptive efficiency  which are not directly in contact with IgE  studies E3_53 displays similar binding affinity for both the locked-complex and free-IgE, while omalizumab scFv binds free-IgE well, but not the locked-complex  Fig.  and bind2–4:FcεRIα-ova complexes. While both clones A4 and 16 showed a modest increase in co-binding of FcεRIα-ova compared to C02 or HAE, clone 7 displayed significantly greater co-binding with a phenotype intermediate to C02 and the non-competitive binder E3_53 :FcεRIα(W156C) complexes could be detected by SEC :FcεRIα(W156C) complex was determined by single particle cryo-EM to a nominal resolution of ~7.3 Å , while the other scFv VL domain is adjacent to FcεRIα (site-2). Both of these novel VL interfaces involve the unique D74H mutation in the E-strand of clone 7 Fig. , providiIn their native binding poses on IgE, omalizumab and FcεRIα would physically overlap each other, suggesting that one or both molecules must be displaced in this intermediate state. Within the antibody, we observe a distortion of the scFv VH/VL conformation relative to the native-C02 structure. Although the low resolution of the EM structure precludes detailed models of these conformational rearrangements, the density and alignment to existing structures supports the following conclusions: 1. The VH domain binding pose remains relatively unperturbed 2. The VL-CDR1 loop, and the site of the most convergent scFv mutations is displaced from the free-IgE binding pose at both sites . Although the low resolution limits a detailed analysis of this alternate conformation, it is clear that FcεRIα undergoes substantial rearrangements to fit large portions of the main chain into the experimental density  and isolated primary human basophils . We therefore produced full IgG1 antibodies of the most efficient disruptive variant (C02), a high-affinity variant (HAE), and a variant that was potently disruptive but bound tightly to the locked complex (clone 16). We then tested each antibodies’ ability to spontaneously activate mouse bone marrow-derived mast cells transgenic for human FcεRIα   , to assess their ability to rapidly desensitize BMMCsly) Fig. . Furtherly) Fig. .tg. Furthermore, both HAE and C02_H2L2 significantly desensitized cells at a concentration of 500 nM in 6 h . SF9 insect cells were infected and supernatants were harvested after 3 days, and purified using Ni-NTA affinity chromatography (Qiagen), followed by size exclusion chromatography (SEC) on a S75 10/300 GL column . The DARPin E2_79 in the pQE-30 vector was transformed into XL-1 blue e. coli. XL-1 E. coli were grown to an OD600 of 0.6 in dYT media, induced in with IPTG at 1 mM for 4–6 h at 37 °C, pelleted, and resuspended in lysis buffer . Resuspended cells were subjected to three freeze thaw cycles, and then sonicated with immersion sonicator. Lysates were treated with EDTA free protease inhibitor tablets (Pierce), clarified by centrifugation at 30,000 × g for 20 min, and filtered through 0.45uM PES filter (Millipore/Sigma). Filtered lysates were then applied Ni-NTA resin column (Qiagen) and further purified by SEC on a S200 10/300 GL column . All remaining recombinant proteins in this manuscript were cloned into pTT5 vector system and transiently expressed in HEK-6E cells32. In brief HEK-6E cells were grown to a density of 2.0 million cells/mL in freestyle media supplemented with G418 at 25 μg/mL and Kolliphor P188 0.1% w/v prior to transfection with precomplexed plasmid DNA (1 mg/L of cells) and 25 kDa PEI (3 mg/L-cells). After 5–6 days secreted protein was harvested following centrifugation of cells at 9000 × g and media clarification with a 0.45 μm PES filter (Millipore/Sigma). Proteins were purified from supernatants with affinity Ni-NTA (Qiagen) or protein-A (GenScript) chromatography before further purification by SEC on HiLoad 16/600 Superdex 200  or Superdex 200 10/300 GL  columns.G335C-IgE-FcProteins were labeled with Alexa Flour 488 NHS-Ester (Thermo Scientific) or Sulfo-NHS-LC-Biotin (Thermo Scientific) in PBS pH 7.4 in a 20:1 label:protein molar excess overnight at 4 degrees. Reactions were quenched with 1 M Tris pH 7.4, and subsequently purified by SEC on HiLoad 16/600 Superdex 200  or Superdex 200 10/300 GL  columns to remove residual biotin or fluorophore labels.A 50% v/v slurry of 4.5–4.9 μm carboxyl-polystyrene particles (Spherotech) in PBS were mixed with FcεRIα-Ova fusion protein at ~2 mg/mL in a 1:1 v/v ration with EDC a 5 mg/mL (Thermo Scientific). The mixture was incubated at room with agitation for two hours, and the resultant conjugated beads were washed with 4 bead volumes of PBE buffer  and stored in PBE with sodium azide at a final concentration 0.02% w/v.2–4, and washed four times with PBS to remove residual bIgE-Fc2–4. Beads were resuspended to a final volume sufficient for 1 μl of slurry per assay-well. 20 μl of each anti-IgE agents was then serially diluted in a V-bottomed 96 well polystyrene plate at 105% the desired concentration, and 1μl of IgE+ beads were added to each well. Plates were incubated at room temperature with agitation (900 rpm) for 30 min prior to fixation with fresh 1.6% PFA in PBS. Fixed beads were then washed and stained for 15 min with 20 μl of a 1:400 dilution of PE/Cy5-Streptavidin  in PBE prior to fixation with fresh 1.6% PFA in PBS. Plates were stored at 4 degrees prior to acquisition.FcεRIα-Ova coupled beads (0.25μl/assay-well of a 50% v/v bead suspension) were incubated for 2 h or overnight with 500 nM biotin-IgE-Fc33. Standard kinetic binding experiments with IgE fragments were also conducted on a Octet-Red 96 (Fortebio). For SCK binding studies with the locked-complex, the locked complex was capture coupled to Ni-NTA tips, coupled with EDC/NHS, quenched with 1 M ethanolamine, and residual nickel atoms were chelated from the resin with 500 mM EDTA pH8.0 prior to binding studies. The tips were then exposed to a serial dilution of anti-IgE agents, starting at the lowest concentration, with association and dissociation times as indicated by experiment. Data was subtracted to blank reference tips exposed to the same serial analyte dilutions, aligned, and exported for analysis in Clamp-XP using a custom 2∶1 SCK binding model as described in detail in Karlsson et al.34.All BLI assays were conducted on an Octet-Red 96 (Fortebio). For anti-IgE SCK affinity measurements, biotin-labeled human IgE was immobilized on streptavidin (SA) tips to a density of ~0.5 nm. The tips were then exposed to a serial dilution of anti-IgE agents, starting at the lowest concentration, with association and dissociation times as indicated by experiment. Data was subtracted to blank reference tips exposed to the same serial analyte dilutions, aligned, and exported for analysis in BiaEval 3.0  using a custom 1∶1 SCK binding model without and RI-term as described in detail in Frenzel et al.To test the ability of soluble omalizumab-IgG variants to disrupt IgE:FcεRIα complexes, FcεRIα-Ova was capture coupled to Ni-NTA tips, coupled with EDC/NHS, quenched with 1 M ethanolamine, and residual nickel atoms were chelated from the resin with 500 mM EDTA pH8.0. Tips were then saturated with recombinant human-IgE prior to incubation with 5μM anti-IgE agents for 15 min to measure dissociation.Prior to transformation EBY100 yeast (ATCC) were grown in YPD media . Transformed yeast controls and libraries were propagated in SD-CAA media  and induced in SG-CAA .3–4 for 30 min, washed, and stained with streptavidin AF-647 conjugate at a 1:400 dilution  prior to acquisition or sorting. For comparative efficiency experiments in Fig. Prior to selection yeast were induced for 24 h at 30 °C in SG-CAA. A tenfold representation of the estimated library diversity, or minimum of 100μl of overnight cultures, was stained prior to each round of selection assuming an approximate cell density of 1E7 cells per mL at OD600 of 1.0. During MACS selections yeast were subject to negative selection with magnetic anti-647 or streptavidin beads and LS columns (Miltenyi Biotec) and subsequently stained for selections as described in figures. After staining, yeast were washed in 50 mL PBE and resuspended in 5 mL PBE with magnetic binder beads (Miltenyi Biotec) for 15 min prior to positive selection over LS columns followed by one 5 mL PBE wash. Column bound yeast were eluted and enumerated on an Accuri Cytometer to estimate library recovery and resuspended at an OD600 < 1 in SD-CAA media for expansion. MACS selections were repeated until the estimated diversity was sufficiently low for FACS selections (1E5–1E6 estimated diversity). FACS selections were performed as indicated in figures on FACS Jazz Sorter (BD Biosciences) in the Stanford Shared Sorting Facility. For yeast efficiency stains yeast were exposed to precomplexed IgE:FcεRIα and AF-488 labeled G335C-IgE-Fc2). Insert DNA was amplified using pCTCon2_F and R primers (F: CGACGATTGAAGGTAGATA CCCATACGACGTTCCAGACTACGCTCTGCAG R: CAGATCTCGAGCTATTACA AGTCCTCTTCAGAAATAAGCTTTTGTTC) with the GeneMorph II random mutagenesis kit (Agilent), band purified, and further amplified with Platinum II Hot Start Mastermix (ThermoFischer). 50μg of insert DNA was mixed with 10μg of triple-cut pCTCon2 vector  and electroporated into electrocompetent yeast at 2500 V in 2 mm gap cuvettes (BioRad MicroPulser). Transformed cells were rescued in YPD for 1 h and then transferred to SD-CAA. Library diversity was estimated by number of transformants on serial diluted SD-CAA plates after 48 h.Electrocompetent cells were produced using a modified lithium acetate (LiAc)/DTT protocol. A 300 mL culture of EBY100 yeast was grown to an OD of 1.6, treated for 15 min with 3 mL of 1 M DTT/1 M Tris and 15 mL of 2 M LiAc/TE solution, and then washed four times with ice cold electroporation buffer  Polyacrylic acid 5100 sodium salt. 813:IgE-Fc3–4: 0.1 M CAPS pH 10.5 40% (v/v) MPD. C02:IgE-Fc3–4: 0.2 M Lithium sulfate, 0.1 M Phosphate citrate pH 4.2 20% (w/v) PEG 1000. HAE:IgE-Fc3–4: 0.1 M Sodium acetate pH 4.6, 8% (w/v) PEG 4000. C02/HAE:IgE-Fc3–4: 0.2 M Lithium sulfate, 0.1 M Sodium acetate pH 4.5, 50% (w/v) PEG 400.All protein complexes were isolated by SEC, concentrated to 10 mg/ml and then screened using a Gryphon crystallization robot (Art Robbins Instruments). All hits from sitting drop screens were reproduced and optimized in hanging drops at 25 °C prior to harvesting and freezing. The final crystallization conditions for each complex are as follows: Omalizumab scFV: IgE-Fc35, solved by molecular replacement (Phenix), and subjected to rounds of model building and refinement (Phenix and Coot)39.Data was collected at SLAC on beamlines 9-2 and 14-1, as well as at the Advanced Photon Source (APS) beamline 21-ID-F. Data was processed using X-Ray Detector Software (XDS)2. A total of 592 image stacks were acquired via the SerialEM 3–6 software suite40 with a defocus range of −1.2 to −2.2 μm. Motion correction was performed with MotionCor241. Initial particle sets were selected using crYOLO with a refined general model (gmodel_phosnet_201912_N63.h5) and a total of 201,285 K particles were selected42. The remainder of data processing was conducted in cryoSPARC v3.0 using patch CTF and particle extraction43. Rounds of 2D classification, ab initio reconstruction, and heterogenous refinement were then used to sort and refine particle sets. The resultant models were used to generate templates for further template-based particle picking using cryoSPARC, and the resultant particles were subjected to rounds of 2D classification, ab initio reconstruction and heterogenous refinement to sort and refine classes. The best resultant class was homogenously refined, and subjected to non-uniform refinement.3.5 µL of purified complexes of clone_7 and locked-complex at a concentration of 4.5 mg/mL was applied to a glow-discharged holey carbon gold grid  with the addition of 0.01% octyl glucoside (OG). Excess protein was blotted away for 2 s with a force of 1 at room temperature in ~100% humidity before being plunge frozen into liquid ethane using a Vitrobot Mark IV (Thermo Fischer Scientific). Cryo-EM images were collected on a Titan Krios operated at 300 kV at a nominal magnification of 29,000× using a Gatan K3 direct electron camera in counting mode, corresponding to a pixel size of 0.8521 Å. Each image was composed of 40 frames with a dose rate of 16 electrons per pixel per second and an exposure time of 2 s, resulting in an accumulated dose of 44 electrons per Å44. The following existing models were used for docking: 1f6a , 4j4p (Cε2), and C02:IgE-this study (scFv). The docked positions were then adjusted using dock-in-map (Phenix), and subjected to real-space refinement with reference and secondary structure restraints with default settings (Phenix)36. Carbohydrates were then automatically built into density maps when possible with Coot39 and were not subject to further refinement.Components of the disruption-intermediate complex were docked into the final map using Chimeratg) from huFcεRIα-transgenic mice ((B6.Cg-Fcer1atm1Knt Tg(FCER1A)1Bhk/J) were derived by 3 to 4 weeks cultivation of bone marrow cells of the femur in BMMC culture medium . BMMCs were characterized by flow cytometry as CD117 + , human FcεRIα + cells .Culture, characterization and differentiation of transgenic genes hFcεRIα + BMMCs . A human basophil culture medium (RPMI+/+) RPMI 1640 medium (Biochrome) was used, supplemented with 10% Hyclone FCS (Fisher Scientific), penicillin 100 U per mL, 100 µg per mL streptomycin and 10 mM HEPES buffer  and recombinant human IL-3 from Peprotec (United States).tg were sensitized with 3 nM human NIP-specific IgE-JW8 (murine lambda chain) overnight at 37 °C in a 5% CO2 atmosphere. Following sensitization, the cells were washed three times with phosphate buffer saline (PBS) pH 7.4. Subsequently, disruptive anti-IgE inhibitors (156 nM–2500 nM), the positive activating anti-IgE Le27 , or an off-target humira control were diluted in supplemented BMMC culture medium MC/9 and added to the sensitized cells for 6 h at 37 °C in 5% CO2 atmosphere. The cells were then washed three times with PBS and divided into two fractions. The first fraction was used to measure the remaining surface IgE with a monoclonal anti-mouse anti-murine lambda chain - PE and the anaphylactogenicity by an activation marker staining. The second fraction of treated BMMCstg were stimulated with 100 ng/mL NIP(7)-BSA  in the presence of an activation marker stain.First, the BMMCs6 cells/ml per well in a round bottom plate with 96 wells in RPMI+/+ supplemented with 10 ng/ml recombinant human IL-3 (rhuIL-3) overnight at 37 °C. To assess the influence of IgE disruption on allergen induced basophil activation, we first defined the 6-grass allergen mix concentration  at which suboptimal activation (ECSubopt.) can be achieved for each individual donor. For this purpose, we cultivated 25'000 basophils in RPMI+/+ medium, which was composed with the 6-grass allergen mix, IL-3, and the Bühlmann Flow CAST® Kit antibody stain (CD63-FITC and CCR3-PE), for 30 min at 37°. Subsequently, we measured activated cells (CD63+ cells) by flow cytometry. In the next step, 50,000 basophils were pre-incubated for 6 h with the disruptive anti-IgE inhibitors or Le27 and humira controls at 37 °C in RPMI+/+ medium with rhuIL-3. Upon incubation, the cells were washed three times with PBS and divided into two fractions. The first fraction was used to measure the remaining surface IgE with an anti-human IgE-PE antibody  and test for anaphylactogenicity with an anti-human CD63-FITC . We used the second fraction to stimulate the cells with the predetermined ECSubopt of the 6-grass allergen mixture in the presence of a Flow CAST® kit antibody stain mix (activation staining of CD63). Finally, we determined activated basophil frequencies and surface measurements by flow cytometry.To evaluate the anaphylactogenicity and the disruptive potency of the disruptive anti-IgE-DARPins we cultured isolated primary human basophils at a density of 1 × 10Tables were generated using Microsoft Excel 14-6, and graphs and analysis were conducted using GraphPad Prism 8–9 unless otherwise noted.Further information on research design is available in the Supplementary InformationPeer Review FileReporting Summary


Regarding the ice periods of the Yellow River, it is difficult to obtain ice data information. To effectively grasp the ice evolution process in the ice periods of the typical reach of the Yellow River, a fixed-point air-coupled radar remote monitoring device is proposed in this paper. The device is mainly composed of an air-coupled radar ice thickness measurement sensor, radar water level measurement sensor, temperature measurement sensor, high-definition infrared night vision instrument, remote switch control, telemetry communication machine, solar and wind power supply, lightning protection, and slewing arm steel tower. The integrated monitoring device can monitor ice thickness, water level, air temperature, ice surface temperature, and other related parameters in real time. At present, devices have obtained the ice change process of fixed points in ice periods from 2020 to 2021. Through a comparison with manual data, the mean error of the monitoring results of the water level and ice thickness was approximately 1 cm. The device realizes the real-time monitoring of ice thickness and water level change in the whole cycle at the fixed position. Through video monitoring, it can take pictures and videos regularly and realize the connection between the visual river and monitoring data. The research results provide a new model and new technology for hydrological monitoring in the ice periods of the Yellow River, which has broad application prospects. The ice disaster of the Yellow River is one of the important natural disasters in the winter and spring seasons from China. According to historical statistics, the ice disaster of Yellow River nearly occurred 30 years ago from 1855 to 1955. Since 1986, there have been 13 ice flood break levees in the Inner Mongolia section of the Yellow River, which have caused huge economic losses and social impact. The Inner Mongolia reach of the Yellow River undergoes different degrees of ice disasters in winter and spring every year, which are affected by the special geographical location and climate conditions ,3. Due tAround the 1980s, scholars worldwide carried out field observations of river ice regimes. Parkinson  and MarsIn view of the ice observations of the Yellow River, the manual ice observation technology is mainly traditional ice observation technology. For example, artificial perforation and ice rulers have been used for the measurement of ice thickness. This method not only has low efficiency, but also has a limited measurement area, which makes it impossible to realize real-time observations. With the development of new technology, different physical methods, such as acoustic waves, electromagnetic waves, and resistivity are emerging to measure ice, which can obtain a large amount of data in a short time without damaging the ice layer ,21,22,23(1)There are few field observation sections in the field and few characteristic sections in particular. At present, the ice factor observation data of the Inner Mongolia section of the Yellow River mainly come from the BayanGaole hydrological station, Sanhuhekou hydrological station, Baotou hydrological station, and Toudaoguai hydrological station. This arrangement is still insufficient to fully understand the formation and development of ice jams, ice dams, and ice disasters of the Yellow River, especially at the bend of the river and the river section prone to ice disasters year round.(2)There are few field observations, and the real-time performance is poor. The existing field observation data are sporadically distributed, some involve only the freeze ice and ice breakup period of a year, and some are in the no-ice period. This makes it difficult to study the ice change law and the ice growth and dissipation change of the Yellow River. In the meantime, the accuracy of the relevant mathematical prediction models is also not high. Therefore, it is necessary to establish a long-term continuous field observation system to obtain the field data of all ice periods of the Yellow River, such as the no-ice period, flow ice period, freeze ice period, and breakup ice period.(3)The field observation data are not comprehensive. At present, the field data of the ice period of the Yellow River mainly include conventional hydrometeorological data, such as temperature, water temperature, water level, ice thickness, etc. The formation and scale of ice dams and ice jams in ice periods are not only determined by conventional hydrometeorological data, but also related to ice thickness, ice transport velocity, and river section conditions. Other factors should also be considered, such as the amount of sediment transport under ice sheets, the amount of river terrain change, and the amount of channel erosion and deposition. Additional factors, such as air pressure, radiation, sediment concentration, and ice density, should be considered in the mathematical models for predicting the freeze-up time and breakup time. Therefore, it is necessary to observe more influencing factors related to ice in the field and establish a thematic database of ice elements and river terrain databases in the future to provide big data support for the accurate analysis of ice in the Yellow River in the future.(4)The field observation equipment and technology are not modern, the degree of automation is low, the field test cycle is long, and the labor intensity is high. Field observation equipment and technology are mostly based on artificial methods, which are inefficient and dangerous, especially in periods of ice jams and ice dams. The technology for monitoring frazil ice formation and migration is still lacking. The ice mechanics parameters need to be obtained by indoor experiments.At present, the main problems of ice monitoring in the Yellow River include four aspects. First, there are few field observation sections, especially characteristic sections. Second, there are few field observation times, and it is difficult to obtain ice information. Third, the field observation equipment and technology are not modern, the degree of automation is low, the real-time performance is poor, and the temporal information of ice is discontinuous. Fourth, the field test time is long, and the labor intensity is high. In view of the special monitoring environment of the Yellow River, the trend of field observations of Yellow River ice is expected to lead toward the realization of all-weather and real-time monitoring of the ice thickness, water level, flow ice density, flow ice speed, and other key ice factors. The main problems are discussed in more detail as follows:Therefore, it is necessary to develop new observation equipment for the ice monitoring of the Yellow River, which should be safe, efficient, convenient, and automatic. Therefore, a fixed-point air-coupled radar remote monitoring device is proposed, which provides new ideas and methods for solving the ice monitoring problem in the Yellow River. Many parameters, such as temperature change, flow ice velocity, flow ice density, ice thickness, and water level, have been obtained and analyzed. Furthermore, the effectiveness of the observation results and the advantages and disadvantages of the device are discussed. Finally, a solution to further improve ice observations is proposed. The research results will further improve the ice prevention monitoring capacity of the Yellow River, promote the field observation technology level, increase the accuracy of ice forecast, reduce ice disaster, minimize the loss of people’s lives and property, and improve the public security defense capacity.The system hardware of the monitoring device mainly includes air-coupled ground penetrating radar, remote switch control and telemetry module, wind and PV hybrid system, GPS module, 4G data transmission module, high-definition infrared night vision instrument (monitoring camera), and other fittings. The components are shown in Air-coupled ground penetrating radar (GPR) is the core component and is used to detect the ice thickness and the distance between the water surface and the radar. The remote computer sends parameters  to the radar through a 4G network and displays, processes, and saves the radar data. After receiving the command, the radar collects the signal and returns the data. The technical parameters are shown in A mobile communication platform (GSM/GPRS network) is used for two-way communication to realize the remote switch control and voltage/temperature control of the system in remote switch control and telemetry modules.There are two main types of wind and photovoltaic (PV) complementary controllers: Pulse width modulation (PWM) controllers and maximum power point tracking (MPPT) solar controllers. The PWM method is used to control the voltage of the battery in a PWM controller. The method is simple, and the charge efficiency is generally approximately 80%. MPPT controllers can detect the generator voltage of the panel in real time and track the highest current value. They can effectively coordinate the work of solar panels, batteries, and loads.The GPS module provides a second pulse signal (PPS) and time information for the radar system. According to the PPS signal, the radar timing controls the interval time of radar data acquisition, and the interval time can be set remotely according to the actual needs. The UTC time information provided by GPS is also recorded in the radar return data, and the radar echo data are time tagged in order that the radar data can be traced back according to the time.A 4G data transmission module is used to realize the long-distance wireless communication between the radar and remote computers.Through field investigation and analysis, it was determined to install a fixed-point air-coupled radar remote monitoring device for ice thickness and water level in the Shisifenzi reach of the Yellow River in Inner Mongolia. The Shisifenzi observation station is located near the Yellow River embankment at the junction of Tuoketuo County and Tumed Right Banner. This section is one of the typical sections of the Yellow River prone to ice flood disasters. The specific location of this reach is shown in (1)HomogeneityWhen the data are returned by the radar, they are processed and analyzed by the remote computer, enabling the ice thickness and the distance between the radar and the ice surface to be obtained. It is necessary to carry out layer tracking algorithm research on the ice surface and ice water interface and automatically analyze the ice thickness and the distance between the radar and the ice surface through the algorithm. This algorithm mainly uses the reflection wave form and intensity characteristics to capture the changes of the ice water interface and ice/water air interface by tracking the event to calculate the ice cover thickness, water surface, and ice distance from the radar. The basis of the algorithm is to extract the transmitting layer and identify the homogeneity and similarity of reflected waves in the same formation. The two properties are used to track the reflecting layer.(2)SimilarityBy comparing of the reflection waves on adjacent frequency channels of the radar spectrum, the lines connected by the same phase of the same reflected wave group on different frequency channels are called the phase axis. The phase characteristics of the same wave group, namely, the position of the wave peak and trough, change slowly along the line.The main characteristics of the same layered reflection wave in the adjacent channel are similar, such as wave form, amplitude, period, and envelope. It is the basis of reflection layer recognition to determine the reflected wave with certain morphological characteristics, and the homogeneity and similarity of reflection waves in the same formation provide the basis for tracking the reflection layer.The change information of the layer position is automatically tracked based on the detection and tracking method of the Markov model. The continuity of the layer reflection echo is that each measuring point is related only to its adjacent measuring points and not to the other measuring points. Based on the viewpoint of probability and statistics, the Markov model is suitable for this situation. Therefore, it can be used to construct the detection and tracing algorithm of the reflecting layer.After the equipment was installed, it operated normally and experienced strong winds, blizzards, low temperatures, heavy fog, and continuously cloudy days. The ice generation and dissipation evolution process of the Shisifenzi reach was observed, including the change in temperature, the change in the flow ice process, the change in ice thickness, and the change in water level.Temperature is the main factor affecting the ice situation of the Yellow River. With the decreasing temperature, flow ice appeared in the river, ice gradually increased, and the river was frozen. Thereafter, with the increasing temperature, the ice gradually melted, the river broke up, and the ice disappeared. The temperature change process of the 2020–2021 ice period is shown in According to the observation and analysis of the test equipment and combined with image recognition technology, the flow ice velocity and density of 2020–2021 were obtained. The evolution process of the flow ice velocity is shown in Flow ice scenes on different dates of the 2020–2021 ice period in the Shisifenzi reach are shown in Based on the suspended air-coupled geological radar technology, ice thickness and water level data were obtained. The change process of ice thickness and water level in the early stage of river ice freezing of the Shisifenzi reach is shown in To effectively verify the effectiveness and accuracy of the test results of the fixed-point air-coupled radar remote monitoring device, a total of 13 manual holes were drilled at the equipment site to measure the ice thickness in the 2020–2021 ice period. The verification results are shown in The device provides fixed-point suspension noncontact integrated continuous monitoring of ice thickness and water level. In addition, it is economical and reliable. Moreover, the device can not only monitor the change process of ice surface elevation, water level under ice, and ice thickness in the ice period, but also monitor the change process of free water surface or ice surface all year round. Furthermore, the device solves four technical difficulties: Air-coupled radar, 25 m long suspension cross bar, integrated solar low-temperature power supply communication, artificial intelligence recognition and identification. The equipment breaks through the technical bottleneck of noncontact and continuous measurement of water level and ice thickness, realizes the real-time monitoring of ice thickness and water level at fixed points, and provides new modes and technologies for hydrological monitoring in ice periods.Since the equipment is fixed, it can observe only the local ice situation and water changes of the Shisifenzi River section and cannot characterize the river ice changes over a wider range. Next, on the one hand, fixed observation points can be added at other typical sections of the Yellow River. In addition, additional monitoring equipment for ice-related parameters can be added to the system, such as spectrum equipment, ice velocity equipment, and solar radiation monitoring equipment. On the other hand, UAV aerial surveys can be combined with fixed-point monitoring, and the river ice change law can be better characterized. The typical change processes of ice generation and disappearance in the Shisifenzi River section are shown in (1)Monitoring technology is a fixed-point, noncontact, and multiparameter ice monitoring technology that can not only synchronously observe the changes in water level and ice thickness, but also observe the ice, water surface temperature, and air temperature, as well as automatically take photos and videos at fixed angles at fixed times and over the whole ice period. The equipment has endured adverse weather conditions, such as blizzards, heavy fog, continuously cloudy days, strong winds above level 10, and a minimum temperature of −31 °C.(2)The temperature change process in the 2020–2021 ice period was continuously monitored. The minimum environmental temperature was −24.93 °C at 23:00 on 6 January, and the minimum ice temperature was −19.97 °C at 1:00 on 7 January in the 2020–2021 ice period.(3)The first flow ice of the 2020–2021 ice period in the Shisifenzi reach of the Yellow River appeared on 24 November 2020. The maximum flow ice velocity was 1.33 m/s, which is in the mainstream velocity region. The average flow ice velocity was 0.5–1 m/s. The flow ice velocity was relatively stable during the whole flow ice period of 2020–2021.(4)The maximum flow ice density occurred on 6 December, which was 85.82%, and then the flow ice density gradually decreased. On 6 December, the river section was frozen and blocked as a whole.(5)The first ice thickness data were accurately captured on 11 December 2021. The maximum ice thickness reached 52 cm. On 26 February 2021, the ice cover broke up, floating ice drifted downstream, the ice thickness data disappeared, and the water level decreased significantly, indicating that the river section opened up. From 3 to 8 March 2021, ice thickness was still measured at the Shisifenzi section, which was mainly caused by floating ice accumulation from upstream.(6)Two methods can be adopted to improve the ice monitoring of the Yellow River: One is to add more representative monitoring points, and the other is the combination of local observations and macropatrol surveys.It is difficult to effectively monitor the ice change process of the Yellow River in the ice period. A fixed-point air-coupled radar remote monitoring device was proposed in this paper. The research results are expected to contribute to improving the ice monitoring ability of the Yellow River, increasing the field observation technology level, and enhancing the ice prediction accuracy and public security defense ability.


An aggressive impact of the formed ice on the surface of man-made objects can ultimately lead to serious consequences in their work. When icing occurs, the quality and characteristics of equipment, instruments, and building structures deteriorate, which affects the durability of their use. Delays in the adoption of measures against icing endanger the safety of air travel and road traffic. Various methods have been developed to combat de-icing, such as mechanical de-icing, the use of salts, the application of a hydrophobic coating to the surfaces, ultrasonic treatment and electric heating. In this review, we summarize the recent advances in the field of anti-icing and analyze the role of various additives and their operating mechanisms. Winter is the most difficult period for the operation of roads in many countries of the world. Along with relevant phenomena during this period such as snowstorms, blizzards and snowfalls, icing is a serious problem for the field of transport and communications. This creates difficulties in the movement of vehicles and in ensuring the safety of road users, and service organizations are not always able to solve this problem.Like other abrasive de-icing products, the utilization of salts is a passive approach to de-icing roads. In terms of composition, anti-icing salts can be divided into three categories: chloride-containing, non-chloride and a mixed one. The first group includes sodium, magnesium, potassium, and calcium chlorides. Sodium chloride (NaCl) is the most popular material because of its abundance. It is traditionally used both in granular form, often mixed with sand, other salts or gravel, and in the form of a saline solution. The theoretical principle of using salts is based on lowering the freezing point, the temperature at which a substance reaches the state of coexistence of solid and liquid phases: when salt is added, the water vapor pressure will be lower than the vapor pressure of ice, and only as a result of lowering the temperature, the phases reach equilibrium ,2,3,4. IThe use of salts as an anti-icing agent is a widespread tactic that has significant disadvantages. Above all, it is accompanied by so-called salt erosion, violating the integrity of the road surface and structural parts, due to which their service life is noticeably reduced . MoreoveZhou et al., revealed a decrease in the ductility of asphalt samples from 9.2% to 27.6% with an increase in the concentration of NaCl solution to 24% at a temperature of 10 °C. This is due to the formation of large crystals by Cl- ions, which block the bond between the molecules of the asphalt, as well as an increase in the proportion of asphaltenes and resins in its composition, with a subsequent decrease in proportion of light components . As a reFor a greater de-icing effect with less environmental impact, the addition of various organic substances is also proposed. Sajid et al.  have addHowever, chloride-based de-icing salt remains one of the main causes of increased salt content in aquatic systems. This process is called secondary salinization and leads not only to a decrease in the amount of fresh water in the sources, but also to an excess of the threshold of chronic toxicity for freshwater organisms, negatively affecting their physiology, reproductive ability, immune functions, interactions between species, etc. ,23,24,252(CH3COO)6) is being considered to be a non-toxic alternative to non-degradable chloride salts to eliminate road icing problems. With a eutectic temperature of −27 °C, it is safe for the environment and is mainly used in aerodromes. The main disadvantages of using this material are its high cost  and secondary pollution during its commercial production based on the chemical reaction of dolomite lime with acetic acid of petroleum origin [2(CH3COO)6 in the desired amount [Calcium magnesium acetate  in emulsified asphalt reduces adhesion between the surface and the formed ice, not only depending on the amount of polytetrafluoroethylene in the material, but also on the method of its addition to the mixture. The adhesion force after 8-h freezing at a temperature of −10 °C with external addition of the agent decreased by about 40%, while for the method of internal addition it increased by 30%, resulting in weaker hydrophobicity . In gene2). After artificial simulation of frosty conditions (1 h of freezing at a temperature of −10 °C and a humidity of 85%), the superhydrophobic asphalt sample remained practically dry . A deep-sea cod, whose skin was the source of protein powder used in the mentioned study, and many other organisms have investigated to produce such substance in the course of evolution. It is noteworthy that with an increase in the AFP content, the contact area between ice and asphalt, and hence adhesion, decreases , and durThus, the use of hydrophobic and superhydrophobic coatings is very promising in course of the prolongation of the service life of the materials and the reduction of the cost for their repair. However, it has also been reported that hydrophobic and superhydrophobic additives can reduce the mechanical strength of the material . MeanwhiVarious composites with thermoelectric properties have found effective application in everyday life. Among them, special attention is paid to their anti-icing properties, which is important for work in cold climates ,60. SuchTo implement this de-icing technology, a simple process diagram has been proposed, according to which a heating material is applied to the substrate surface in the form of a thin film a. When tCarbon materials due to their unique properties have found application in the anti-icing technology ,76,77,782) in the open air. After removing the ice, the sample further prevented the formation of ice on its surface.By measuring the electrical and thermal properties using infrared thermography, it was determined that among all the samples, the most effective were the samples with CNT suspensions of 2 wt.% and 3 wt.%. Their electrical resistance values are 806 ohms and 23.2 kΩ, respectively. Z-axis  required to achieve a given temperature value at a given time and the applied external potential (V), this technology can replace traditional electric heaters and radiators  in a polymer matrix on a 3D printer using the fused deposition modeling . As a reTo demonstrate the effectiveness of the developed panels, the field tests were carried out onboard the patrol vessel in the Norwegian Sea c. Anti-iThe formation of ice on the roads often leads to accidents of vehicles, in some cases it ends with the closure of roads until complete clearing of icing. Among the known consequences are cases when people fall when walking on such roads and get serious injuries. To avoid such cases, salt is poured onto the roads, which is harmful to the environment . Less exIn , scientiThe results of investigations based on comparing the time to reach 0 °C for concrete blocks with different types of carbon fibers embedded are shown in Microwave ice removal is a method characterized by rapid and selective heating and higher thermal efficiency ,99,100. In addition, the results of tests for de-icing with microwaves demonstrate that CFMC-3 has the fastest heating rate of 1680 °C/s, which is 4.46 times higher than that of PC b. Even tMultiwalled carbon nanotubes (MWCNT) can also be applied for de-icing purposes ,105,106.When tested at different voltages  at room temperature, it was found that the temperature of the CNFP increased rapidly in a short period of time due to the unique electrothermal properties of the single CNF and the CNFP microrelief .Despite the good results, there are a number of other problems that hinder the use of anti-icing techniques on a large scale. One of these is the economic disadvantage of using microwave absorbers and conductive fillers in large areas of road surface ,110,111.For anti-icing systems, their installation is required at the stage of roadway construction, since this affects the volume of operation and the cost of the system. In order to save energy, systems with heating should not work unnecessarily, they must be manually controlled, but it is much more practical to use the automatic mode of turning on and off heating, which will independently work with the help of special sensors only when there is a danger of ice formation. It is also important that after the ice has melted, its additional removal is required, since the accumulated liquid after turning off the system will turn back into ice. To avoid this, it is necessary to take into account the ways to remove the melted snow and ice from their initial place of heating at the design. During liquid, electrothermal heating and heating using radiation, the authors do not take into account the need to establish heat-insulating layers, which will help prevent heat loss due to soil heating.This review summarizes the research activity related to the protection of surfaces from icing. The de-icing methods related to the use of hydrophobic coatings, thermoelectric heating, and microwave exposure are briefly described. Despite the effectiveness of removing ice from the surface, for the widespread use of a certain method the following characteristics such as energy saving, reliability in a long period of their operation and environmental safety are important. For example, for hydrophobic coatings, the parameters of their wear resistance and slip resistance are important. In the case of using nanomaterials, despite their unique properties, their addition to the concrete structure may not be economically profitable. Most of the published papers demonstrate the effectiveness of such developments, however they are not widely used in everyday life, leaving the potential for the further developments in this direction.In the case of using various salts and polymer coatings for anti-icing purposes, the research should be focused on the addition of various agents due to which, the anti-icing, environmental friendliness, adhesion and anti-corrosion properties would be improved. At the same time, such substances should either reduce the adhesion of ice (as much as possible to reduce the force of adhesion of ice to the surface and maintain this ability for a long period of operation), or lower the freezing point of water on the protected surface. In the case of using electricity, besides its cost, the additional supervisory personnel are required to monitor the operation of technical equipment and their safety. In this regard, it is necessary to develop automatic systems for their independent operation.


The recent emergence of anti-immunoglobulin E (IgE) drugs and their candidates for humans has endorsed the significance of IgE-dependent pathways in allergic disorders. IgE is distributed locally in the tissues or systemically to confer a sensory mechanism in a domain of adaptive immunity to the otherwise innate type of effector cells, namely, mast cells and basophils. Bound on the high-affinity IgE receptor FcεRI, IgE enables fast memory responses against revisiting threats of venoms, parasites, and bacteria. However, the dysregulation of IgE-dependent reactions leads to potentially life-threatening allergic diseases, such as asthma and anaphylaxis. Therefore, reactivity of the IgE sensor is fine-tuned by various IgE-associating molecules. In this review, we discuss the mechanistic basis for how IgE-dependent mast cell activation is regulated by the IgE-associating molecules, including the newly developed therapeutic candidates. Immunoglobulin E (IgE) is a unique Ig isotype with the lowest serum concentration, which confers a sensory mechanism of adaptive immunity to the otherwise innate type of effector cells, including mast cells and basophils. Its relatively long half-life ~3 weeks) on the high-affinity IgE receptor FcεRI, together with the minute-order response time, enables protection from the invasive venoms  and fast weeks onIgE functions through its receptors. The high-affinity receptor FcεRI is a heterotetramer, comprising an IgE-binding α chain, a signal-amplifying β chain, and two signal-initiating γ chains ,5,6 Fig. The β aHuman FcεRI has another assembly of αγ2 chains, which is expressed in several cell types, including dendritic cells (DCs). It plays a role in facilitating antigen presentation ,15. Alth5 receptors per cell at the steady state [An early study has determined the number of FcεRI expressed on the rat peritoneal mast cells as approximately 3 × 10dy state . Considedy state ,21, theody state . Howeverdy state . For insdy state   and comSeveral studies have investigated FcεRI distribution and the proximal signaling events ,34,35,36In an early study, Torigoe et al. used two related antigens, 2,4-dinitro-phenyl (DNP) and 2-nitrophenyl (NP) to investigate whether IgE-sensitization can distinguish between antigens with different affinities. The affinity of anti-DNP IgE toward NP moiety is approximately 1/1000 of the original affinity toward DNP. Using these antigens, the authors adjusted the NP antigen concentration such that FcεRI β and γ phosphorylation is more than that in DNP-stimulated cells. However, NP-induced degranulation was only one-tenth of DNP-induced degranulation . Later, The clustering of FcεRI is cardinal to its activation. It seems that the cluster size is more dependent on soluble antigen concentration than its affinity ,33. LargAnti-IgE monoclonal antibodies effectively crosslink IgE and activate mast cells, suggesting that the valency of two is sufficient for the cognate antigen to form clusters. However, the antigen concentration required for activation decreases with the increase in valency . In addiFinally, Hjort et al. reported the effects of the clonality of IgEs with various combinations of affinities to a natural antigen . In concHRF is a ubiquitously expressed protein cloned as a factor with an IgE-dependent histamine-releasing activity on human basophils ,44. It iInterestingly, the prerequisite for basophils to respond to HRF is sensitization with IgE from certain atopic individuals ,49. ThosNevertheless, Kashiwakura et al. reasoned that IgE may have heterogeneity in terms of HRF reactivity and tested various IgE clones. Indeed, approximately 30% of the IgE clones were found to bind HRF . The HRFIn the crystal structure of HRF dimer, which is disulfide-bonded at the C-terminal end C172, the distance between the N19 and H3 regions was approximately 4 nm, while the distance between the two H3 regions was 6 nm . AlthougThe N19 or H3 fragment of HRF, or the HRF-2CA  competitively inhibits the binding of HRF to the HRF-reactive IgE. Using these HRF inhibitors, HRF was shown to play a role in IgE-dependent allergic inflammation in the skin, the airway, and the intestine ,54,55. IBesides patients with food allergy, patients with atopic dermatitis (AD) , chronicN-terminally truncated HRF dimers have been reported to have another cytokine-like function exerted through its flexible loop and helix H2 ,62. This−5 s−1) [10 M−1, which is in the order of Ka for antibody-antigen binding [Ig structure is often depicted as a Y-character-like scheme with two heavy chains and two light chains . This sc−5 s−1) ,72. The  binding . Tight b6–107 M−1, the avidity of the trimer to IgE is considered to be close to that of FcεRI. Interestingly, the binding of CD23 and FcεRI to the IgE is mutually exclusive; the binding of CD23 to the hinge region of Cε3 and Cε4 allosterically close the binding site of FcεRI (closed form). Conversely, the binding of FcεRI (open form) to Cε3 makes the CD23 binding site inaccessible. This mutual exclusion mechanism ensures that the IgEs on cell surface FcεRI cannot be mistakenly crosslinked by cell–cell contact with CD23-expressing cells. It is also noteworthy that both soluble FcεRIα fragment [In addition to bending, another important conformational concept of IgE is “closed” and “open” forms C. IgE hafragment ,74,75 anfragment ,77,78 mafragment .®) is the first and most characterized. The efficacy of omalizumab is shown for many allergic diseases, including allergic asthma [Antibodies and other substances targeting IgE have been developed to treat allergic diseases . Omalizuc asthma ,81,82,83c asthma ,85, nasac asthma ,87, and c asthma , and appc asthma . These rOmalizumab is a recombinant humanized IgG1κ monoclonal antibody that specifically binds the Cε3 domain of human IgE. Omalizumab specifically binds free IgE (not bound to FcεRI) and blocks its binding to both FcεRI or CD23 receptors. Since it does not affect the FcεRI-bound IgEs, the reduction of IgE on mast cells takes longer (~70 days) than that on basophils (~7 days), depending on their half-lives ,91. The It seems that the crystallization of the complex of IgE-Fc and omalizumab Fab requires some tweaking, such as constraining the Cε3-4 conformation to be “closed” by the introduction of an extra disulfide bond (G335C) , or inhiInterestingly, the allosteric effect exerted by omalizumab made the bent knees of Cε3 more open than that of FcεRI-bound conformation. In line with this, omalizumab can facilitate the dissociation of IgE from FcεRI, although at a very high concentration that cannot be achieved in the therapeutic use (50 μM = 7.5 mg/mL) .An antibody Fab fragment aεFab described above binds mainly at the Cε3 portion of the human IgE. The bent form of free IgE exposes one binding site for aεFab, and this binding is enough for inhibiting the binding of FcεRI. In the bent form, it has steric hindrance with FcεRI, and in the extended form, it has an allosteric hindrance . At highMEDI4212 is another antibody against IgE, which underwent a clinical trial. MEDI4212 was developed from the parent IgG ENG085, which was selected as a human single-chain variable fragment by a large phage library. The X-ray co-crystallography with the Cε3-4 fragment showed that MEDI4212 binds the Cε3 portion and keeps it in an “open” conformation, suggesting that its mode of action is steric hindrance for FcεRI and allosteric hindrance for CD23 . MEDI421Ligelizumab (QGE031) is also a humanized IgG1 monoclonal antibody that binds with higher affinity to the Cε3 domain of IgE than omalizumab does. Despite its failure in the treatment of severe asthma , it showIntriguingly, although the FcεRI binding inhibition potency of ligelizumab is higher than that of omalizumab, that on CD23 is lower compared to that of omalizumab ,99. FromDARPins (designed ankyrin repeat proteins) are a relatively new class of synthetic proteins derived from natural ankyrin repeat proteins, which can be designed to have diverse binding specificities . The DARIn addition to the Cε3 domain, the Cε3-4 region has been targeted. Single-domain antibody (sdab) 026 is a llama-derived, humanized sdab-targeting Cε3-4 region of human IgE . The binIn addition to Cε3 and Cε4, Hirano et al. recently reported that a Fab fragment (clone 6HD5)-binding murine Cε2 reduces mast cell activation in vivo and in vitro . InteresAnother strategy to suppress IgE is to reduce production. Quilizumab is a humanized, afucosylated, monoclonal IgG1 antibody targeting the M1-prime segment present only in membrane-type IgE. It was intended to remove memory IgE B cells. Despite the successful reduction in antigen-specific and total IgEs by up to 40%, it failed to improve CSU  and inadAIMab7195 (former XmAb7195) is a humanized, modified IgG1 monoclonal antibody, with enhanced binding activity on FcγRIIb . FcγRIIbBispecific IgE/CD3 antibody (bsc-IgE/CD3) has also been developed to eliminate IgE-producing B cells . It was Other drug candidates targeting IgE include DNA aptamer . HoweverIgE is a heavily glycosylated molecule, with seven N-glycosylation sites in human IgE and nine N-glycosylation sites in mouse IgE. To date, there are no known O-glycosylation sites in IgEs. Most of these sites have complex glycans, except for N394 in humans and N384 in mice, which are conjugated with oligomannose glycans ,123. IntEscherichia coli (aglycosylated) and mammalian cells (glycosylated). These studies primarily focused on their effects on FcεRI binding. Despite the inconsistent results reported in earlier studies, recent mutational studies on each N-glycan site of whole IgE expressed in mammalian cells have concluded the absolute requirement of N394 glycosylation for binding to FcεRI [The functions of these glycosylations have been extensively studied using glycan digestive enzymes and recombinant proteins produced in to FcεRI ,123,124.to FcεRI ,123, andThe structural basis for the role of the N394 glycan remains obscure. A crystallography of a human IgE fragment detected the first GlcNAc on N394 glycan at the interface of Cε2 and Cε3 and a potential hydrogen bond with D271 on Cε2 . In thisAlthough these enzymatic and mutational strategies can introduce all-or-none modifications of desired N-glycans, the glycan composition is heterogenous and subject to change in health and disease conditions. In addition, it is well established that the composition of the N297 glycan on human IgG1 determines its functional consequences . A recenGalectins are a family of β-galactoside-binding lectins with 15 members in mammals . They arGalectin-3  was first cloned as an IgE-binding molecule  and was Gal-9 is another galectin that binds to glycans on the IgE molecule . Gal-9-bDuring the past 55 years, since the discovery of IgE, the development of new technologies has enabled detailed analysis of a structural, physicochemical, and molecular biological basis for the IgE-dependent activation of mast cells. The efforts to elucidate the true nature of IgE have revealed that this single molecule, in fact, has a diversity; the conformation is flexible, the glycosylation may change in health and diseases, and the reactivity to antigens and IgE-interacting molecules such as histamine-releasing factor may vary. The heterogeneity of IgE and their ligand antigens are sensed via FcεRI and translated into a variety of modes of activation in mast cells. A recent report demonstrated that IgE-antigen immune complexes are less bound by FcεRI and sequestered through CD23 binding, whereas the free IgE is preferred by FcεRI . This is


The combination of screw fixation and cage can provide stability in lumbar interbody fusion (LIF), which is an important technique to treat lumbar degeneration diseases. As the narrow surface cage is developed in oblique lateral lumbar interbody fusion (OL-LIF), screw fixation should be improved at the same time. We used the finite element (FE) method to investigate the biomechanics response by three different ways of screw fixation in OL-LIF.  Using a validated FE model, OL-LIF with 3 different screw fixations was simulated, including percutaneous transverterbral screw (PTVS) fixation, percutaneous cortical bone trajectory screw (PCBTS) fixation, and percutaneous transpedical screw (PPS) fixation. Range of motion (ROM), vertebral body displacement, cage displacement, cage stress, cortical bone stress, and screw stress were compared.  ROM in FE models significantly decreased by 84-89% in flexion, 91-93% in extension, 78-89% in right and left lateral bending, and 73-82% in right and left axial rotation compared to the original model. The maximum displacement of the vertebral body and the cage in six motions except for the extension of model PTVS was the smallest among models. Meanwhile, the model PTVS had the higher stress of screw-rods system and also the lowest stress of cage. In all moments, the maximum stresses of the cages were lower than their yield stress.  Three screw fixations can highly restrict the surgical functional spinal unit (FSU). PTVS provided the better stability than the other two screw fixations. It may be a good choice for OL-LIF. Screw fixation with cage in lumbar interbody fusion (LIF) is a key technique to treat lumbar disease degeneration. Wide surface cages were used in some minimally invasive LIF, such as oblique lumbar interbody fusion (O-LIF), direct/extreme lateral interbody fusion (DLIF/XLIF), and anterior lumbar interbody fusion (ALIF). However, injuries to the paraspinal nerves and vessels sometimes occur , 2. CurrSince 1973, Belytschko et al.  first deThe study was approved by the authors' affiliated institutions ethics committee. A FE software ABAQUS 6.14-4  was used to create a FE model of the L4-L5 functional spinal unit (FSU). The mesh sensitivity test and model validation have been done in previous study; the result of which is in a good agreement with other published experiments [The inferior endplate of L5 was fully constrained. 500 N upper body weight in the lumbar spine was simulated by a compressive follower load with path through the centroids of two vertebral bodies . The momCompared with the original model, ROMs of the three surgical models were significantly decreased by 84-89% in flexion, 91-93% in extension, 78-89% in right and left lateral bending, and 73-82% in right and left axial rotation . Model PAmong the models, the maximum displacement of the vertebral body and of the cage in model PTVS was the lowest in five moments, except that the extension was similar Figures  and 6. MThe maximum stress of the L4 cortical bone in model PTVS was larger than the other two models in all moments . The larStability of the lumbar spine refers to the ability of the lumbar to cope with the physiological load of daily life, which is mainly maintained by the lumbar intervertebral disc, facet joint, intervertebral ligaments, and muscles. LIF with screw-rods system combined with cage can provide a strong stability for the lumbar segment and create an environment for the transplanted bone tissue for solid fusion. The way of screw fixation and the size of the cage both affect the stability of postoperative FSU. As the minimally invasive spinal surgery developed, the size of the cage got smaller than before to match the endoscopic working tunnel. When the cage changed, the screws should be enhanced. PTVS, PCBTS, and PPS have actually been put on the professional treatment of spinal disease. This study utilized a finite element method to assess the biomechanics of three screw fixations in endoscopic LIF. The result provided engineering evidence to the surgeon for reference in the clinical setting.The ROM and the maximum displacement of the FE model can directly reflect the stability of the postoperative model. The smaller the ROM and displacement of FE model were, the greater the limit of the model activity, and the better the stability of the postoperative model. A solid stability of the postoperative FSU is good for intervertebral bone fusion because the micromotion of the cage in the intervertebral space can hinder bone fusion , 22. In In LIF, after discectomy, the stability of FSU was mainly maintained by the cage and screw-rods system in addition to the facet joint and posterior osseous ligament complex. The stress of the cage was inversely proportional to that of the screw-rods system. The smaller the stress of cage, the greater the stress experienced by the screw-rods system, especially in minimally invasive LIF. In flexion, PTVS prevented L4 from moving downward and shared the pressure caused by L4, so the strain and stress of the cage were reduced Figures  and 9. OThe contact area between the PTVS and the cortical bone of the vertebral body was small, so it was easy to cause local contact stress concentration. However, the stress concentration was not obvious from the result of calculation. The stress distribution of PTVS is more even than that of the other two fixations. The maximum stress of the PTVS was distributed more evenly in the screw body, while those of the PCBTS and PPS were distributed at the junction between the screw body and the screw head. PTVS has a longer body than PCBTS and PPS. Longer screw in the vertebral body could provide a better fatigue test, which could a bear better circulating load . Using tFrom the discussion above, it can be found that PTVS had the better stability than the other two screw fixations. Crossing the multiple layers of the cortical bone, PTVS effectively constrained the FSU sharing load stress with cage. With PTVS, the narrow surface cage in LIF was hardly destroyed. In the future, when the material of the screw improves and the fatigue test was passed, maybe there is no need for using the cage in LIF.The model of this study selected a FSU and did not simulate the whole lumbar vertebral model. The effect on the postoperative adjacent lumbar intervertebral disc was not considered. Cyclic load on the lumbar was not taken into account. Some components were simplified, e.g., the ligaments were modeled as an axial connector. The bone graft and postoperative residual annular fibrous were not constructed in the models because until bone fusion neither of these structures could provide immediate mechanical support after surgery. The cage was also simplified to remove the serrated surface. In our future study, the fatigue failure test of screws and cage will be investigated.This study used a finite element method to develop three surgical models to simulate OL-LIF. The result showed PTVS restricted the model most displacement among models. Postoperative PTVS could provide strong stability for FSU immediately. PTVS combined with a narrow surface cage may be a good choice for OL-LIF.