A variety of urease inhibitors have been proposed to reduce NH3 volatilization by interfering with the urease activity. We report a quantum mechanics/molecular mechanics molecular dynamics (QM/MM MD) study on the mechanism employed for the inhibition of urease by three representative competitive inhibitors; namely, acetohydroxamic acid (AHA), hydroxyurea (HU), and N-(n-butyl)phosphorictriamide (NBPTO). The possible connections between the structural and thermodynamical properties and the experimentally observed inhibition efficiency were evaluated and characterized. We demonstrate that the binding affinity decreases in the order NBPTO >> AHA > HU in terms of the computed activation and reaction free energies. This trend also indicates that NBPTO shows the highest inhibitory activity and the lowest IC50 value of 2.1 nM, followed by AHA (42 μM) and HU (100 μM). It was also found that the X=O moiety (X = carbon or phosphorous) plays a crucial role in the inhibitor binding process. These findings not only elucidate why the potent urease inhibitors are effective but also have implications for the design of new inhibitors.Soil bacteria can produce urease, which catalyzes the hydrolysis of urea to ammonia (NH T. T2′TS1,drolysis . Figure 2′Int, we examined the elimination process caused by proton transfer from WB to the departing NHOH group of HU based on the reaction coordinate set for the H(WB)•••N(HU) separation in the range from 0.90 to 2.70 Å (denoted as CV d6). All three of the QM/MM metadynamics simulations demonstrated the same reaction mechanism involving Asp363-assisted proton transfer, as illustrated in 2′TS2 interconnects between 2′Int and the product state 2′P, where the product carbamate is tridentately bound to the nickel center and NH2OH is released  and Nε(His222) and N(HU) and Nδ(His323) are 2.88 ± 0.15 and 2.99 ± 0.35 Å, respectively. As shown by the analysis of the trajectories, the proton can move back and forth between the isolated hydroxylamine group and the carboxylate group of Asp363, existing as either NH2OH and the deprotonated Asp363 or NHOH– and the protonated Asp363 , as shown in 2′RSQMb). At the QM-only level, the hydrolysis of hydroxyurea was found to proceed similarly to that of urea, in that the elimination processes involving proton transfer followed by C–N bond cleavage require larger activation barriers than the nucleophilic attack process [Unlike the results for  process . The act process .2 and 2′ suggested that these reactions are competitive and, because of this, HU might function simultaneously as a substrate and irreversible inhibitor, which is in good agreement with the experimental results [2 is involved in the generation of the dead-end complex 2P, where an HU-derived compound is irreversibly bound to the active site by chelating Ni1. On the other hand, in the other binding mode 2′, HU was found to undergo hydrolysis catalyzed by urease. Since NH2OH produced by hydrolysis has no inhibitory activity towards urease, the generated carbamate in 2′P is supposed to be decomposed into NH3 and bicarbonate, as can be observed in urea hydrolysis. Although the amount of NH3 arising from HU hydrolysis is half of that arising from urea hydrolysis, the inhibition activity of HU is inferior to that of AHA, and this reflects the difference in the IC50 values (42 vs. 100 μM).Comparison of the results for  results ,10. The N-(n-butyl) thiophosphoric triamide (NBPT), which is the most well-known phosporamidate-type urease inhibitor in agriculture, is a pro-drug of NBPTO. Analogous to other phosporamidate derivatives, NBPTO works as a suicide substrate and shows a substantially low IC50 value of 2.1 nM. When NBPTO approaches the active site, urease mistakenly classifies it as a true substrate and hydrolyzes it to diamido phosphoric acid (DAP) and n-butylamine instead of releasing NH3. The resulting transition-state analog DAP is strongly bound to the active site of urease in a tridentate manner; thus, the binding of another urea molecule can be blocked. We investigated the relationship between the high inhibitory activity of NBPTO and DAP formation catalyzed by urease. Specifically, we assessed whether NBPTO hydrolysis is essentially the same as urea hydrolysis or whether it is subject to a different reaction pathway.Finally, the inhibition process for NBPTO was explored. 3RS) was obtained  are generated.We first attempted to track the formation of a tetrahedral intermediate that would be the precursor of DAP, with the reaction coordinate set to the O(WB)•••P(NBPTO) separation ranging from 1.40 to 3.20 Å (denoted as CV d7). However, all metadynamics simulations failed to determine an appropriate free energy profile for the nucleophilic addition reaction. In contrast to the case of urea hydrolysis, the P–OH bond is not likely to be formed. For this reason, we predicted that P–O bond formation would coincide with P–N bond scission via an Asp363-assisted proton migration reaction from WB to the amine N atom. The H(WB)•••N(NBPTO) distance in a range of 0.90 to 2.70 Å was chosen as the reaction coordinate. Looking at the 1D-PMFs shown in n-butylamine is produced, its NH2 group forms a hydrogen bond with Asp363 and the proton moves back and forth between n-butylamine and Asp363 •••Nε(His222) separations of 2.90 ± 0.20 Å. No hydrogen-bonding interactions were detected between His323 and the amino group of NBPTO that were not coordinated with Ni2. Our data support the notion that the presence of a C=O or P=O moiety is mandatory for potent inhibition of urease, as NBPTO with a P=O bond shows much better inhibition than NBPT with no P=O bond in the region of four orders of magnitude [After d Asp363 . The resagnitude .1, 2, and 2′, the UB3LYP-D3BJ geometry optimization demonstrated a proper bindentate NBPTO-bound complex (3RSQM), as shown in 3RSQM appears to be comparable to 3RS  [Ka values computed with the PROPKA3 program [The X-ray crystal structure of fluoride-inhibited ry 6QDY) . The flury 6QDY) . The QM  program ,36, and  program . Concern program ,40,41,42 program ,44 in co program , which i program  computed program . The Len program . The CHA program .+ ions using the Visual Molecular Dynamics (VMD) program [−6. The electrostatic and van der Waals interactions were cut off at 14 Å with a switching distance of 12 Å. The system was minimized over 2000 steps, which was followed by a 10 ns classical MD simulation using the NAMD program [Subsequently, each system was immersed in a 100 × 110 × 100 Å rectangular box of water molecules and neutralized with two Na program . Classic program  with a t program . During  program . The resThe QM/MM MD equilibrations were carried out with NAMD , ORCA 4 and the 1), the first CV (d1) represented proton transfer from the hydrogen atom of AHA to the WB, and the second one (d2) indicated the dissociation of the formed H2O molecule through the breaking of both the Ni1–O and Ni2–O bonds. The same was applied for the CVs for the reaction involving HU (2) (d3 and d4). For the CVs for the hydrolysis of HU (2’), the first CV (d5) represented the nucleophilic attack of the bridging oxo on the carbonyl carbon atom, and the second CV (d6) indicated the elimination of the generated NH3. The CV for the process of inhibition by NBPTO (3) (d7) represented the P(NBPTO)–O(WB) binding, proton transfer, and the dissociation of n-butylamine, all of which occur concurrently. On these bases, 1D-PMFs for the inhibition mechanisms were evaluated in the NVT ensemble at 300 K. The time step, hill weight, hill width, and hill frequency were set to 0.5 fs, 0.40 kcal/mol, 2.5 Å, and 50 fs, respectively. The simulation time ranged from 15 to 50 ps, depending on the type of reaction and the choice of reaction coordinates, as mentioned above. One barrier recrossing over the transition state was taken as the convergence criterion, as recommended in literature studies [2O, NH2OH, and n-butylamine—moved away from the reaction site and the systems did not return to the reactant states. Thus, for the latter cases, we optimized the simulation times for each case, so that three independent runs generated consistent PMFs and the simulations were deemed to have converged.After that, we performed three independent QM(GFN2-xTB)/MM(CHARMM36) metadynamics simulations  to deter studies ,62,63. A1–3 predicted by the GFN2-xTB/CHARMM36 MD simulations were also explored at the UB3LYP-D3BJ/def2-SVP level of theory, together with QM-only cluster models. For each system, the total charge and spin multiplicities were set to 1. The open-shell singlet solutions were generated using the FlipSpin and FinalMs keywords available in ORCA. To exclude artificial intramolecular interactions, we constructed each QM-only cluster model by removing the second sphere amino acids  and replacing Lys220* and histidines with methylcarbamic acid and imidazole  >> AHA (42 μM) > HU (100 μM) in terms of increasing ICOverall, it should be emphasized that hydrogen bonding with His222 and Ni2–N amine bond formation are crucial for anchoring an inhibitor to the active site and for stabilizing the intermediate and final product complex. These findings not only elucidate why the existing urease inhibitors are effective but also have implications for the design of new inhibitors.


The present study described the most recent findings concerning the abundance and distribution of plastic in water, sediment, and fauna in the Nile River of Upper Egypt as an interesting research point. The findings revealed that plastics were abundant in the water, sediments, fish, and crayfish throughout the sites. The Nagaa Hammadi site has the highest abundance of meso- and macroplastics in its water and sediment. African catfish had the highest abundance of meso- and macroplastics compared to the other species, while Nile tilapia had no meso- or macroplastics in its alimentary canal or gills in all sites. The Edfu site has the highest abundance of mesoplastics in the alimentary canals of African catfish, while the Nagaa Hammadi site has the highest abundance of mesoplastics in the gills, and macroplastics appeared only in the alimentary canal of African catfish from the El-wasta site. Only mesoplastics were found in the crayfish’s alimentary canal, with the Nagaa Hammadi site having the highest abundance. No macroplastics were detected in the crayfish’s gills or alimentary canal. Additionally, this work lets us understand how plastics behave in freshwater environments, and it is a step toward decision-makers taking appropriate measures to reduce their risk. One of the main contributors to the so-called novel entities, which are being referred to as a “chemical intensification” as a result of the increasing global chemical production and the expanding global distribution of chemical products or consumer goods, are plastic polymers that degrade to microplastics  and African catfish Clarias gariepinus (N = 6), and an invertebrate species, crayfish Procamparus clarkii (N = 35). The collected species were carefully placed in an ice box and transported to the lab for further processing. The alimentary canal and gills were removed and individually studied for each sample after their length and weight were measured. The animal species were collected using fishing nets and long lines. A dissecting binuclear microscope was used to visually investigate the meso- or macroplastics (> 0.5 cm)  was collected using a labeled plastic bottle from each site. The samples were then sent to the lab for further analysis. Before being visually examined, each water sample (100 mL) was filtered through Whatman Nuclepore Hydrophilic Membrane filter paper (8 μm mesh size), and meso- (0.5–2.5 cm) and macroplastics (> 2.5 cm) were removed. Three sediment samples (1 kg each) were collected from each site using a Van Veen grab sampler  to test for significant differences between them. Data were analyzed using the SPSS program, version 16. Differences between means were compared using Duncan’s multiple range tests at a During the collection of water and sediment samples, different levels of abundance and composition of plastic waste were observed on the shores of the three sites. Nagaa Hammadi has the most abundant and composed site in plastic, followed by El-wasta, while Edfu was the least abundant and composed site in plastic. The average of the total numbers of meso- and macroplastic in water and sediment in the three sites  is displayed in Table The number of fish that was collected from each site  was seven fish, with an average length of 17.3, 20.08, and 23.3 cm and an average weight of 102.1, 178.5, and 122.1 g, respectively. The result shows that Nile tilapia collected from the three sites were not contaminated by meso- or macroplastics, neither in the alimentary canal nor in the gills  in the alimentary canal of C. gariepinus collected from El-wasta. The most dominant mesoplastic color was white, followed by black, yellow, and orange in the alimentary canal, and El-wasta had a greater variety of colors. While in the gills, only two colors appeared from the mesoplastics: white and transparent in El-wasta and Nagaa Hammadi, and no mesoplastics were determined from gills collected from Edfu  were six fish, with an average length of 36.3, 39.4, and 39.2 cm and average weight of 306.6, 485, and 500.8 g, respectively  were thirty-five, with average lengths of 8.9, 11.4, and 11.6 cm and average weights of 12.2, 28.7, and 28.7 g, respectively , and fishing gear are just a few examples of the various anthropogenic sources that contribute to the abundance of plastic waste along the Nile River shoreline. These plastics originated from human activities such as fishing, tourism, and urban garbage  and their appearance in the African catfish (Clarias gariepinus) are due to the fact that their feeding habits have a significant impact on the amount of plastic waste they consume  in their digestive tract, which could be attributed to the smaller size of plastic targeted in this study versus the size targeted in our study. Another study supported by Jabeen et al. , may be able to penetrate fish tissue and cross intestinal barriers, allowing them to enter the human food chain , plus their colors, could reduce the dangers that this pollution poses to river Nile fauna. The reduction of plastic consumption is one of the primary requirements for managing plastic debris in the river Nile and lowering its detrimental impacts on the freshwater ecosystem.


Giardia intestinalis is a protozoan parasite that causes diarrhea in humans. Using single-particle cryo-electron microscopy, we have determined high-resolution structures of six naturally populated translocation intermediates, from ribosomes isolated directly from actively growing Giardia cells. The highly compact and uniquely GC-rich Giardia ribosomes possess eukaryotic rRNAs and ribosomal proteins, but retain some bacterial features. The translocation intermediates, with naturally bound tRNAs and eukaryotic elongation factor 2 (eEF2), display characteristic ribosomal intersubunit rotation and small subunit’s head swiveling—universal for translocation. In addition, we observe the eukaryote-specific ‘subunit rolling’ dynamics, albeit with limited features. Finally, the eEF2·GDP state features a uniquely positioned ‘leaving phosphate (Pi)’ that proposes hitherto unknown molecular events of Pi and eEF2 release from the ribosome at the final stage of translocation. In summary, our study elucidates the mechanism of translocation in the protists and illustrates evolution of the translation machinery from bacteria to eukaryotes from both the structural and mechanistic perspectives. Translation elongation involves three sequential reactions: (i) decoding and accommodation of aminoacyl tRNA in the A (aminoacyl tRNA) site; (ii) peptide bond formation followed by generation of pre-translocation (PRE-T) complex with deacylated tRNA in the P (peptidyl tRNA) site and peptidyl tRNA in the A site; and (iii) translocation of A- and P-site tRNAs to the P and E (exit) sites through multiple substeps resulting in the post-translocation (POST-T) state ready for next cycle of elongation [reviewed in ]. TranslThe role of EF-G in tRNA translocation has been extensively investigated in bacteria through biochemical ,16–18, sDespite similarity in the main mechanism of tRNA translocation along all three kingdoms of life, differences exist between eukaryotes and bacteria. This is partially due to different architecture of the tRNA binding sites that lead to different interactions of the tRNAs with the ribosome ,42,43. FGiardia lamblia   extensions  ,51, whiltensions ,50. Alontensions . HoweverGiardia intestinalis  is a flagellated, amitochondrial, binucleated, protozoan parasite of the order Diplomonadida, which causes diarrhea in humans and other mammals  were maintained in TYI-S-33 medium. For the experiment, the cells were grown in 50 ml centrifugation tubes. At a cell density of around 1 × 106 cells/ml, the cells were harvested by cooling the tubes on ice for 15 min, agitating the tubes repeatedly to detach the cells from the tube walls and centrifuging the tubes at 2000 × g and 4°C for 5 min. The supernatant was decanted; the pellets were washed twice in PBS and pooled into microcentrifugation tubes with ∼0.7 ml of pellet each. These pellets were stored at −80°C until ribosome extraction.G. intestinalis were prepared according to 2, 20 mM Tris–HCl (pH 7.6) and 6 mM β-ME). Lysis was carried out by vortexing the resuspended trophozoites with 300 mg of silica beads (0.5 mm diameter) for 10 min with intermediate incubation on ice. Lysate was clarified by centrifugation at 20 000 × g for 30 min at 4°C. To separate the ribosomes from other cellular contents, the cleared lysate was layered on 30% sucrose cushion in a low-salt buffer with 1:1 ratio and centrifuged for 2 h at 250 000 × g in a Sorvall RC M150 GX ultracentrifuge. The ribosome pellets were washed and resuspended in a high-salt buffer . For further clarification, resuspended ribosomes were layered on a 30% sucrose cushion prepared in a high-salt buffer and centrifuged as above. The resulted ribosome pellets were washed and resuspended in HEPES–polymix buffer  (Ribosomes from rding to  with min buffer]  and furt2 per frame (4 frames/s) were captured with 7654 image stacks in total.Grids used for imaging were R2/2 300 mesh copper grids (Quantifoil) with a 2 nm amorphous carbon layer. The grids were glow discharged  immediately before use. Vitrification of the sample (3 μl) was done using a Vitrobot Mark IV . Grids were screened on a Talos Arctica (FEI Thermo Fisher) and imaged on a Titan Krios (FEI Thermo Fisher) at 300 keV using a K2 direct electron detector (Gatan) at a resolution of 0.82 Å/pixel and nominal defocus of 1.2 μm. Image stacks of 20 frames with electron dose of 1.5 e/Åde novoGiardia ribosome structure, though the poor density of the unmasked regions of the ribosome indicated significant residual structural heterogeneity. Structural heterogeneity was addressed first with 3D refinement using a large subunit mask , followed by two rounds of fixed orientation 3D classification. The first round of fixed orientation 3D classification using SSU mask dealt with the conformational heterogeneity attributable to the SSU . The second round of fixed orientation 3D classification was employed on each distinct SSU conformation using a mask encompassing the P stalk, APE sites and the L1 stalk  followed by assignment of mutations and insertions/deletions as peripheral regions of the ribosomal rRNA were added. Initial Giardia r-protein structures and eEF2 were predicted using Phyre2  between it and the remaining three states  . Two steG. intestinalis ribosome at an overall resolution of 2.95 Å  or yeast  rRNA, but comparable with the 4556 nt long Escherichia coli rRNA. Several rRNA ESs are shortened, which can probably be attributed to its parasitic lifestyle  despite almost no ESs  and the peptidyl transferase center (PTC) constitute the main functional centers on the ribosome and are therefore potential targets for small-molecule inhibitors. We analyzed the ribosome , E. coliribosome  and the Giardia, A1492, A1493 and G530 in E. coli, A1755, A1756 and G577 in S. cerevisiae, and A1447, A1448 and G483 in P. furiosus  and G1409 (similar to E. coli G1491)  Figure .E. coli, U2873 in S. cerevisiae and U2619 in P. furiosus. The conformation of this nucleotide is regulated by its interaction with two additional nucleotides, which are C2055 and A2572 in E. coli  of eL42 , which interacts with the CCA end of the E-site tRNA. This reiterates that the E site of the Giardia ribosome has a specific eukaryotic architecture.In contrast to the DC and PTC, the E site of the 2 Figure . FurtherGiardia ribosome  present an amalgam of bacterial and eukaryotic features and (ii) can be sensitive to some bacteria-specific translation inhibitors.Intersubunit bridges in the ribosome allow communication between the LSU and SSU during protein synthesis. Eukaryotic cytoplasmic ribosomes have five additional intersubunit bridges located mostly peripherally (except eB14), which are attributed to the preferential rotated state of the eukaryotic ribosomes ,66,75. Is Figure . LikewisE. coli and A2256 in S. cerevisiae) were seen interacting with the codon–anticodon pairs  with the 5′ end, as seen in the C and D states.State B represents an eEF2-bound transient translocation intermediate in which eEF2 is bound to GDP and the leaving Pi Figures  and B. TS. cerevisiae ribosome  shows a completely closed L1-stalk and E-site tRNA, while the other substates (II through VI) show snapshots of a continuum of movement of the L1 stalk with the final state (A-VI) having no bound tRNAs and an L1-stalk angle of 39°  to the axis of subunit rotation (state C → state D), but inclined at an angle of 32° with respect to each other  are close to the E site, the absence of these two bridges in the POST-T state is likely to be the main reason for the negligible size change in the E site during subunit rolling. Thus, Giardia ribosome demonstrates an intermediate ‘subunit rolling’ in its elongation cycle with a distinct difference of insignificant widening of the E site compared to higher eukaryotes.Next, we looked for changes in the size of the A site  and the E site (distance between G2217 of 25S and U667 of 18S). We observed ‘subunit rolling’-specific narrowing of the A site by ∼6 Å in the PRE-T state, similar to the earlier report in human ribosomes (∼5 Å)  wherein domain I is the GTPase domain or G domain  in SRL . A . A Giards Figure  held by s Figure . Superimh Figure . One intribosome . This inS. cerevisiae, eEF2 domain III-N499 interacts with K82 of uS12. In this structure, the SSU body is in the rotated state. However, in three late translocation-intermediate states of mammalian 80S    where th-POST-2)  and C.G. intestinalis add insightful details regarding ribosomal translocation. We discuss below the main observations in the light of translocation mechanism, drug sensitivity and evolution of translational machinery.In recent years, our knowledge about the steps of translation has progressed significantly due to the technical advances in cryo-EM. Our observations of translocation intermediates of the native ribosomes of G. intestinalis are highly compact with significantly reduced ES and with uniquely high GC content. While it contains all characteristic eukaryotic rRNAs and most of the eukaryotic r-proteins, a closer look at the functional centers lifts up the bacterial ribosome-specific features, which enable us to reflect on the prospects of drug binding.The ribosomes of E. coli is regulated by the nucleotides A1408 and G1491, which are replaced with G1645 and A1754 in S. cerevisiae. G1645 occludes aminoglycosides with 6′-substitution in ring I (e.g. neomycin with amino group substitution) except those with hydroxyl group substitution (e.g. geneticin and paromomycin). Similarly, A1754 prohibits aminoglycosides with 5″-hydroxyl group in ring III, e.g. neomycin and paromomycin from binding  (S. cerevisiae ribosomes with A1754G mutation are ∼60-fold more sensitive to paromomycin and 10-fold more sensitive to G418 (geneticin)   (Supplemd A1754) . A previneticin) . Since GS. cerevisiae, A2397 interacts with U2873 to accommodate the eukaryote-specific PTC inhibitors  similar to C2055 in E. coli. Hence, we suspect that the bacteria-specific A-site inhibitors, e.g. clindamycin and chloramphenicol, might inhibit Giardia ribosomes  in place of A2572 in E. coli, which suggests that Giardia and T. vaginalis ribosomes might be resistant to tiamulin.In s Figure . Howeverenteriae . GiardiaE. coli  or with antibiotics trapping eEF2 on the ribosome  even in the absence of EF-G/eEF2, oscillating between classical and hybrid states  (S. cerevisiae (GDPCP) (State B resembles a translocation intermediate with eEF2 bound to GDP and the leaving Pi in a unique position. Comparison of our structure with the EF-G/eEF2-bound early translocation intermediates from DP + Pi)  and S. c (GDPCP) , and lat (GDPCP)  reveals  (GDPCP) .Escherichia coli EF-G in the GDP + Pi state has been seen as bound to the ribosome in a fully rotated state (PDB: 7PJV) (S. cerevisiae ribosome (B: 7PJV) . Sw-I ofribosome , which cribosome .We conclude that post-GTP hydrolysis, SSU body back-rotation pulls down domain III of EF-2 via uS12, which in turn pulls back Sw-II with the catalytic His, thereby guiding the Pi release. It is plausible that we managed to trap this naturally populated state due to the interactions of EF-2 domain IV with SSU head, which acts as a ‘door-stop’ and prevents further SSU back-ratcheting and loss of interactions with uS12.Giardia is a protozoan parasite that diverged early from the eukaryotic branch  protein–RNA interaction, e.g. S. cerevisiae, and (iii) RNA–RNA interaction, e.g. H. sapiens.Comparison of the ractions . Howevereviously . Interesaginalis . In contbranches . Thus, ibranches . Combinihttps://github.com/andy-emmo/ribosome-building-analysis and https://doi.org/10.5281/zenodo.7670234.The cryo-EM maps and atomic coordinates generated in this study have been deposited in the Electron Microscopy Data Bank and Protein Data Bank (see gkad176_Supplemental_FilesClick here for additional data file.


Biomechanical and finite element analyses were performed to investigate the efficacy of second-generation bone cement-injectable cannulated pedicle screws (CICPS) in osteoporosis.This study used the biomechanical test module of polyurethane to simulate osteoporotic cancellous bone. Polymethylmethacrylate (PMMA) bone cement was used to anchor the pedicle screws in the module. The specimens were divided into two groups for the mechanical tests: the experimental group (second-generation CICPS) and control group (first-generation CICPS). Safety was evaluated using maximum shear force, static bending, and dynamic bending tests. Biomechanical stability evaluations included the maximum axial pullout force and rotary torque tests. X-ray imaging and computed tomography were used to evaluate the distribution of bone cement 24 h after PMMA injection, and stress distribution at the screw fracture and screw–cement–bone interface was assessed using finite element analysis.P < 0.05). The bending moments of the experimental group (128.5 ± 9.08 N) were comparable to those of the control group . The screw-in and spin-out torques of the experimental group were higher than those of the control group . Bone cement was mainly distributed at the front three-fifths of the screw in both groups, but the distribution was more uniform in the experimental group than in the control group. After pullout, the bone cement was closely connected to the screw, without loosening or fragmentation. In the finite element analysis, stress on the second-generation CICPS was concentrated at the proximal screw outlet, whereas stress on the first-generation CICPS was concentrated at the screw neck, and the screw–bone cement–bone interface stress of the experimental group was smaller than that of the control group.Mechanical testing revealed that the experimental group (349.8 ± 28.6 N) had a higher maximum axial pullout force than the control group (277.3 ± 8.6 N; These findings suggest that second-generation CICPS have higher safety and stability than first-generation CICPS and may be a superior choice for the treatment of osteoporosis. An aging population is increasingly becoming a global problem, and spinal degenerative diseases are now frequently diagnosed in older patients. Pain caused by intervertebral disc herniation, spinal stenosis, and spondylolysis impose a heavy burden on the economy, and seriously affect the health and quality of life of patients . SurgeryPedicle screw fixation has been widely used in the surgical treatment of spinal degenerative diseases –5; howevPolymethylmethacrylate (PMMA)-reinforced screws have been proven to be the most effective system for strengthening pedicle screws and achieving stable fixation , 8–11. PSince the initial application of first-generation cement-injectable cannulated pedicle screws (CICPS) enhanced with PMMA in clinical practice in 2011, the incidence of screw loosening, bone cement leakage, and even pulmonary embolism has reduced –18.In 1975, Liu et al. , 21 and To further optimize screw design and reduce complications, we have improved the design of first-generation CICPS to create second-generation CICPS. This study aimed to evaluate screw safety through biomechanical experiments and analyze stress distribution at the screw fracture and screw–cement–bone interface using finite element analysis.Second-generation CICPS design features a dual thread with an inner diameter of 1.6 mm, a thread lead of 6 mm, and a pitch of 1.5 mm in the proximal two-fifths and 3 mm in the distal three-fifths. The three side holes in the front two-fifths of the screw are separated from each other by 120° and two threads. From the near to far sides, the holes are round (2 × 2 mm), oval (3 × 2 mm), and U-shaped (4 × 2 mm) and can be designed with different specifications. All pedicle screws used in this study were manufactured by Chongqing FWS Medical Device Co., Ltd.  and had a diameter of 6.5 mm and a length of 45 mm  was used to simulate the mechanical properties of osteoporotic cancellous bone. An open cone was used to drill holes in the side of the specimen, and a nail hole with a depth of 40 mm was prepared perpendicular to the side of the specimen. After installation of the screw placement instrument, the pedicle screw was slowly screwed vertically into the cancellous bone substitute, until the screw head was in contact with the surface of the specimen. During screw placement, the specimen structure was protected from damage by left–right shaking. All specimens were used self-tapping screws to avoid weakening the screw-holding force . The long axis of the adjusting screw was perpendicular to the bending direction, and the load was applied at a constant rate of 25 mm/min perpendicular to the long axis of the pedicle screw. A computer automatically recorded the continuity value and drew the load–displacement curve until the load dropped significantly Fig. A.Fig. 3E6 cycles.This was performed using a fatigue tester (model no. Fd3000-P), with the screw installed in the same manner as in the above test, and the maximum loads set at 65%, 75%, and 80% of the yield load. The loading wave was sinusoidal, R-value was 0.1, and frequency was 10 Hz. Dynamic tests were conducted for each screw in turn, and the load–cycle curves were drawn using a computer analysis of the results until the screw broke or the cycle stopped at 2.5 × 10This was performed using a surgical implant electromagnetic dynamic mechanics test system (model no. M-100T). The adjusting screw was perpendicular to the specimen surface and a force of 11.17 N was applied vertically at a constant torsional speed of 3 r/min. The computer automatically recorded the continuity value and drew the torque–angular displacement curve; the recording stopped when all threads had entered the module. Unscrewing was performed in the same manner until the threads had completely exited the module . The long axis of the adjusting screw was parallel to the stretching direction. The screw was pulled out along the long axis of the pedicle screw at a constant rate of 5 mm/min. The computer automatically recorded the continuity value and drew the load–displacement curve until the load dropped significantly Fig. A.Fig. 4E6 cycles  with maximum loads of 1000, 1500, and 2000 N. The loading wave was a sine wave with an R-value of 0.1 and a frequency of 5 Hz. Dynamic tests were carried out for each screw in turn, and the load–cycle curves were drawn by computer analysis of the results until the screw broke or the cycles stopped at 2.5 × 10les Fig. B.The CT scan results at 0.625 mm intervals were imported into SolidWorks geometric model processing software version 1.0 , and ANSYS Workbench software version 19.0  was used for the finite element calculation. Screw and screw–cement–bone models were established by meshing. A grid convergence analysis was conducted, and the network type was a 10-node tetrahedral element, as shown in Fig. Screw Fig. B and scrTable P value < 0.05 was considered significant. Comparisons of all indices between the two groups were performed using a two-tailed Student’s t-test or analysis of variance.All statistical analyses were performed using SPSS software version 21 ; a P > 0.05).As shown in Fig. As presented in Fig. P < 0.01). The spin-out torque of second-generation CICPS (0.764 ± 0.027 N) was also higher than that of first-generation CICPS .As presented in Fig. P < 0.05).As shown in Fig. As presented in Fig. The results of the simulated dynamic bending test Fig.  show thaThe results of the simulated maximum axial pullout force test Fig.  showed tTranspedicular screw instrumentation is regarded as a proven surgical procedure in the treatment of spinal diseases, achieving rigid stability in the anterior, middle, and posterior layers of the spine. However, surgical failure due to loosening, breaking, or pulling of the screw can occur, with screw pullout being one of the most common clinical complications , 31.3 to simulate normal bone, reduced bone mass, and osteoporotic bone, respectively, to compare screw fixation stability. They concluded that screw fixation strength significantly correlated with bone density and thread design. An osteoporosis-simulating PU bone block was used in our study. The second-generation screw adopts a double-thread design because of its smaller pitch and greater number of threads, thus, resulting in a larger contact area with the bone block, greater influence of friction at the screw–bone interface, and higher screw-in torque than that of the first-generation screw. A higher torque also means a stronger fixation effect, reducing the probability of screw pullout and further improving screw stability.Many studies have reported methods to improve pedicle screw stability, including changing the shape of the screw, redesigning the screw threads, increasing the screw diameter, and reducing the screw pitch , 32–37. In the static bending experiment, the limit bending moment of the second-generation screw was lower than that of the first-generation screw, indicating that the first-generation screw should have better ductility. However, in the dynamic bending experiment, the force of the limit bending moment of the first-generation screw was less than that of the second-generation screw; in the maximum shear force experiment, the second-generation screw could withstand more cycles under the same force. Unlike conventional screw breakage that occurs in the neck, breakage of the second-generation screw occurs in the proximal lateral hole of the screw. We have reason to believe that the cause of this phenomenon is that the double-thread design changed the original stress distribution, making the stress distribution of the second-generation screw more uniform. Screw fracture occurred in the proximal side hole because it is closer to the thread change; structural changes are more susceptible to the influence of mechanics and are also more likely to exhibit morphological changes.Many studies have reported the use of PMMA to improve the stability of osteoporotic spinal pedicle screws –45. Liu In the finite element analysis, the simulated maximum shear force test showed that the neck maximum stress value of 1029.7 N for the first-generation screw was much higher than the maximum stress value of the proximal side hole at 424, 27 N, whereas the neck maximum stress value of 1046.2 N for the second-generation screw was not significantly different from the maximum stress value of the proximal side hole at 1002.9 N. This result is compatible with the mechanical experiments, which further shows that the double-thread design can change the stress distribution and failure form of the screws. The simulated maximum pullout force test of the screw–cement–bone interface as a whole showed that the force of second-generation CICPS (157.26 N) is less than the force of first-generation CICPS(282.95 N). The results show that more evenly distributed cement allows the screw–cement–bone interface to bear more uniform forces and results in greater stability between the internal structures.First, simulated osteoporotic cancellous bone was selected for use in this study; however, the actual vertebral body is composed of cancellous bone and skin mass, which may result in some deviations from the experimental data. Second, the stress process was the result of a series of complex and comprehensive effects, and mechanical tests were completed under specific conditions and parameter sets; thus, the experimental results are not fully applicable to clinical practice. Finally, it is difficult to accurately simulate the real properties of materials using their geometric properties, which means that further experiments are required.Future studies should collect more data in animal models of osteoporosis to further verify the safety and stability of second-generation CICPS prior to clinical application.The double-thread design results in a stronger pullout force, and the evenly arranged side holes make the cement package more uniform, resulting in less screw–cement–bone interface stress. The experimental results suggest that second-generation CICPS are safer and more stable than first-generation CICPS and represent a better choice for the surgical treatment of osteoporosis and spinal degenerative diseases.


Here, we show that the inhibition potencies of brigatinib and crizotinib on pOCTs are isoform- and substrate-dependent. Human OCT3 (hOCT3) and multidrug and toxin extrusion protein 1 (hMATE1) were highly sensitive to inhibition by brigatinib and crizotinib for all three tested substrates. Apart from hMATE1, substrate-dependent inhibition was observed for all other transporters with varying degrees of dependency; hOCT1 inhibition showed the greatest substrate dependency, with differences in IC50 values of up to 22-fold across the tested substrates, followed by hOCT2 and hMATE2-K, with differences in IC50 values of up to 16- and 12-fold, respectively. Conversely, hOCT3 inhibition only showed a moderate substrate dependency (IC50 variance < 4.8). Among the substrates used, metformin was consistently shown to be the most sensitive substrate, followed by mIBG and MPP+. Pre-incubation of ALK inhibitors had little impact on their potencies toward hOCT2 and hMATE1. Our results underscore the complexity of the interactions between substrates and the inhibitors of pOCTs and have important implications for the clinical use of ALK inhibitors and their DDI predictions.Small molecules targeting aberrant anaplastic lymphoma kinase (ALK) are active against ALK-positive non-small-cell lung cancers and neuroblastoma. Several targeted tyrosine kinase inhibitors (TKIs) have been shown to interact with polyspecific organic cation transporters (pOCTs), raising concerns about potential drug–drug interactions (DDIs). The purpose of this study was to assess the interaction of ALK inhibitors with pOCTs and the impact of substrate-dependent inhibition on the prediction of DDIs. Inhibition assays were conducted in transporter-overexpressing cells using meta-iodobenzylguanidine (mIBG), metformin, or 1-methyl-4-phenylpyridinium (MPP+) as the substrate. The half-maximal inhibitory concentrations (IC Anaplastic lymphoma kinase (ALK) is a neural receptor tyrosine kinase (RTK) in the insulin receptor superfamily that is predominantly expressed in the central and peripheral nervous system . MutatioPolyspecific organic cation transporters (pOCTs) belong to the family of human solute carrier (SLC) transporters, which facilitate the cellular influx and efflux of different drug molecules and toxins, as well as many endogenous organic cations ,14. Thismax) to its half-maximal inhibitory concentration (IC50) is greater than 0.1, further in vivo DDI assessment is recommended metformin (112 mCi/mmol) and [3H]1-methyl-4-phenylpyridinium  were purchased from American Radiolabeled Chemicals, Inc. . Acetonitrile (ACN) and formic acid (liquid chromatography with tandem mass spectrometry (LC-MS/MS)-grade) were obtained from Thermo Fisher Scientific . Reagents for cell culture were purchased from Invitrogen .MIBG, crizotinib, lorlatinib, and glyburide were purchased from Sigma-Aldrich . Erlotinib was kindly provided by Dr. Rheem Totah. Brigatinib was purchased from MedChemExpress . metformin and [3H]MPP+, assays were performed in the same manner as for mIBG, but the cells were instead lysed with 100 μL of 1 M NaOH for 1 h at 37 °C and subsequently neutralized with 100 μL of 1 M HCl, of which 150 μL of the total cell lysate was used for total radioactivity analysis using a Tri-Carb Liquid Scintillation Counter . For preincubation assays, cells were preincubated with the TKIs in HBSS for 30 min before the initiation of substrate uptake.Uptake assays were performed as previously described . In brie1/2 ~ 13 h for 123I and 8 days for 131I), nonradioactive mIBG was used and quantified by LC-MS/MS as previously described [m/z) transitions used were 276.1 → 217.0 for mIBG and 494.1 → 369.0 for glyburide.Due to concerns about rapid iodine isotope decay . The lower limit of quantification (LLOQ) of mIBG was 0.1 nM, and the calibration curve was linear up to 8 μM. Non-linear regression was used to fit the data on GraphPad Prism 7.0  to generate graphs and calculate parameters. For the dose-dependent inhibition assay, the ICErlotinib, lorlatinib, and brigatinib were used at a relatively low concentration of 20 μM for the initial screening to determine their inhibitory effects on the transport of mIBG by hOCT1-3 and hMATE1/2-K. Data for crizotinib are not shown here, as it was screened previously . At the 50 values for brigatinib and crizotinib were determined, with substrates being used at concentrations much lower than their corresponding Km values. Brigatinib inhibition of hOCT3 was 14-fold and at least 100-fold more potent than that of hOCT1 and hOCT2, respectively, and its inhibition of hMATE1 was at least 50-fold more potent than of hMATE2-K  is given. While time-dependent inhibition has been previously observed in some transporters, such as the organic anion-transporting polypeptides (OATP) 1B1 and 3 ,41, it rSmall molecules targeting aberrant ALK have been proven effective against ALK-positive NSCLC and NBL. These ALK inhibitors are often used alongside standard chemotherapy or other drugs to combat resistance, which subsequently raises concerns about potential DDIs. Here, we investigated the interactions between selected ALK inhibitors and pOCTs and determined whether their inhibition of hOCT1-3 and hMATE1/2-K was substrate- and isoform-dependent. Our results reveal that brigatinib and crizotinib potently and selectively inhibit hOCTs and hMATEs in an isoform- and substrate-dependent manner. Both hOCT3 and hMATE1 exhibit high sensitivity towards inhibition by brigatinib and crizotinib, regardless of the substrate used. Aside from hMATE1, substrate-dependent inhibition was observed for all other transporters, with varying degrees of dependency. These findings have multiple implications for the clinical use of ALK inhibitors in cancer patients and for in vitro to in vivo DDI predictions for pOCTs.max/IC50 ratio (Radiolabeled mIBG serves as a therapeutic and diagnostic agent for neuroendocrine tumors, including NBL. Beyond tumor cells, mIBG is strongly accumulated in the heart, liver, and salivary glands, which can lead to unwanted toxicity in these normal tissues ,43. Our 50 ratio . NonetheMetformin, an oral hypoglycemic drug, is a primary treatment for type 2 diabetes, a condition that might share certain risk factors with cancer . It has Although both metformin and MPP+ are recommended by the ITC and the FDA as probe substrates for evaluating transporter-mediated DDIs toward OCTs and MATEs, substrate-dependent inhibition has been reported in the literature . A previUnlike other pOCTs, the inhibition of hMATE1 by crizotinib and brigatinib is not influenced by the substrate . This isTime-dependent inhibition has been observed previously with OATP1B1 and 3 ,41. ClinIn summary, our results show significant substrate-dependent inhibition of hOCT1-3 and hMATE2-K, but not of hMATE1, and demonstrate the importance of probe substrate choice in the prediction of in vivo DDIs with ALK inhibitors. These results underscore the complex mechanisms of the interactions between substrates and inhibitors of pOCTs and provide evidence that warrants further investigation of potential transporter-mediated DDIs between TKIs and clinically relevant victim drugs.


A southerly oceanward pathway beneath the ice sheet is the most likely drainage route of these GLOF events based on the available surface- and bed-elevation datasets. Furthermore, the 2017 event occurred during the austral winter, thereby implying the possibility of year-round active subglacial networks in Antarctica. Our results highlight that studies on Antarctic ice-marginal lakes provide an opportunity to better understand Antarctic hydrological processes and emphasize the need for both detailed monitoring of ice-marginal lakes and detailed surveying of the subglacial environments of the Antarctic Ice Sheet.The liquid water around the Antarctic Ice Sheet plays a key role in modulating both the vulnerability of ice shelves to hydrofracturing and ice discharge from outlet glaciers. Therefore, it needs to be adequately constrained for precise future projections of ice-mass loss and global sea-level rise. Although glacial lake outburst floods (GLOFs) pose one of the greatest risks in glacierized mountainous regions, any long-term monitoring of Antarctic ice-marginal lakes and their associated potential for GLOFs has been neglected until recently owing to the limited number of such events reported in Antarctica. Here we present direct evidence of repeated GLOFs from Lake Kaminotani-Ike, an ice-sheet-dammed lake in East Antarctica, via an analysis of historical aerial photographs and recent satellite data. Two GLOFs occurred in 1969–1971 and 2017, with discharge volumes of (8.6 ± 1.5) × 10 Recent studies have revealed that the hydrology of Antarctica plays a key role in sea-level rise by modulating the ice dynamics of AIS outlet glaciers and ice shelves7. The ongoing increase in supraglacial lakes has the potential to destabilize ice shelves via hydrofracturing8, although supraglacial streams can weaken this process by reducing lake storage via water transport9. Subsequent acceleration of the inland ice may occur if the ice shelf collapses12 and/or meltwater drainage reaches the subglacial environment5. Outburst floods from subglacial lakes have accelerated the downglacier flow of outlet glaciers by altering the subglacial hydrological environment13. However, the hydrological processes behind such events are not well constrained because of the remoteness of the subglacial environment. Despite the importance of cryo-hydrology in the evolution of AIS, studies of ice-marginal and/or ice-dammed lakes are extremely limited, thereby limiting our understanding of AIS hydrology.The Antarctic Ice Sheet (AIS) is the largest potential contributor to sea-level rise17. Furthermore, these freshwater pulses can impact ocean circulation, biochemical circulation, and marine ecosystems20. For example, GLOFs from the largest-scale glacial lakes that were located along the periphery of past ice sheets weakened ocean circulation, thereby modulating climate22. However, GLOFs from ice-marginal and ice-dammed lakes in Antarctica have largely been neglected due to extremely limited reports of GLOFs until recently26. Although outbursts from subglacial, supraglacial, and sub-surface lakes are generally associated with either a collapse of the surrounding ice or ice doline formation29, the subglacial and englacial hydrological processes behind such events are not well constrained due to the rarity of these events and the inherent difficulty in obtaining direct observations. The lack of ice-marginal lake monitoring in Antarctica limits our understanding of the impacts that GLOFs have on ice-sheet/glacier dynamics and the surrounding environment. Furthermore, constraints on GLOFs in Antarctica may advance our understanding of lake–ice interactions in harsh environments, even though they pose a lower risk compared to other regions.Glacial lake outburst floods (GLOFs), which abruptly discharge their stored water and lake materials downstream, are a common phenomenon that has been observed at ice-marginal lakes in glacierized regions worldwide, with the exception of Antarctica, and are recognized as one of the greatest risks in mountain societies30. Therefore, the lake water likely originates from subglacial discharge that is directly fed by EAIS and meltwater of solid precipitation over the catchment. Members of the 59th Japanese Antarctic Research Expedition (JARE59) observed several unusual features at LKI on 22 November 2017, including the exposed lake floor, a vertical ice cliff at the boundary between the lake and EAIS, and snow and ice blocks scattered along the lake shore31  is an ice-dammed  lake in East Antarctica. LKI is situated ~ 60 km south of Syowa Station and is located between the Skarvsnes outcrop and the East AIS . A comparison of Landsat 8 satellite images acquired on 22 February and 11 October 2017 clearly highlighted changes in the surface features of LKI  and DEMs that were constructed by applying the structure-from-motion (SfM) technique to the JARE aerial photographs (SfM-DEMs). DEMs clearly capture a drop in surface elevation across LKI in 1969–1971 and 2017  × 107 m3 from LKI during P1 and P2, respectively  and 2.5 × 106 m3 a−1 after P2 (the 2017–2021 period). The time series clearly highlights two GLOFs that are followed by periods of gradual lake filling  to construct a dense time series of the lake-surface elevation and relative lake volume Fig. . The lak39, (2) conduit formation beneath/within the ice dam40, and (3) mechanical collapse41. Evidence of these different outburst mechanisms have been observed in the field at Antarctic glacial lakes, even though Antarctic GLOF studies are limited. For example, the 2019 Untersee GLOF was initiated by water outflow at the lake margin, which was confirmed by field inspections25. The Yatsude Valley GLOF was probably caused via the subglacial hydrological system, with the formation of a near-circular hole at/near the base of the ice dam inferred23. There were no observations of a discernible hole, trace of failure in the ice dam, or surface-water overflow during the 2017 field inspection and in the images that were acquired after the 2017 LKI GLOF event. However, the lake-surface elevations immediately prior to the 1969–1971 and 2017 LKI GLOFs were quite similar. Therefore, we assumed that the triggering mechanism of the LKI GLOFs was related to the flotation criterion of the ice dam, as observed for GLOFs from other ice-dammed lakes42. Even if the ice dam achieved flotation, the glacier uplift may not be detectable in the satellite-based DEMs due to the expected small-scale vertical motion of the ice dam 39.Outbursts from ice-dammed lakes are generally caused by either a break in the seal (between the glacier bottom and bedrock) or overflow of the ice dam/lake margin. Seal-break mechanisms are classified as (1) flotation43 because it is currently the only available bed-elevation dataset that covers our study region. The regions where This flotation hypothesis could be investigated by analyzing the ice-surface, ice-sheet bed, and lake-surface elevations. The elevation difference between the lake level and flotation level, 43 and floating condition of ice-dam that calculated from the surface elevations of the ice sheet and lake, which implies that the available bed-elevation data do not satisfy the flotation threshold. A > 10-m increase in the lake level is required to reach flotation based on the available bed-elevation constraints. Nevertheless, the actual threshold is less than ~ 20 m due to the effect of the gradual opening of the subglacial seal44. This assumption is based on the idea of ice deformation on the lakeward side as a “cantilever” effect, whereby the accumulated lake water induces buoyancy-driven uplift of the glacier-ice. Furthermore, the errors in the bed-elevation dataset introduce uncertainties in the exact location of the drainage route owing to the coarse resolution (500 m) and large uncertainties (100–1000 m) of the employed bed-elevation dataset. We note that these large uncertainties are due to a lack of measurements across the study region and the fact that the BedMachine dataset43 is designed for large-scale studies that incorporate either the entirety of Antarctica or regional catchments. We observed > 100 m of ice-cliff retreat  of the ice damming the lake, which are currently unconstrained for LKI and the surrounding area. Recent increases in rainfall and intensive melting along the periphery of EAIS, which have been attributed to changes in atmospheric conditions52, may both accelerate the occurrence of the next LKI GLOF event and increase the frequency of future GLOF events at LKI and other ice-marginal lakes. Nevertheless, there are limited examples of GLOFs associated with ice-dammed lakes in Antarctica, and the time series of these events are too short to distinguish their periodicity26. Thus, continued monitoring of the ice-dammed lakes in Antarctica is needed to further discuss the potential periodicity of GLOFs and how a changing global climate may impact this periodicity.Our long-term observations provide the first evidence of repeated GLOFs from an ice-marginal lake in Antarctica Figs.  and 3. A53 also highlight the need to monitor ice-marginal lakes in Antarctica, as continued warming will alter AIS dynamics and atmospheric conditions in the coming decades and centuries55. Detailed mapping of the ice-dammed and ice-marginal lakes around AIS is recommended to assess the contribution of such lakes as potential GLOF sources, as has been done for the Greenland Ice Sheet56. Furthermore, our results imply a possible subglacial water input into the lake, even during the austral winter. Subglacial water has been observed beneath the Greenland Ice Sheet and is recognized as a key factor in modulating ice movement58. In fact, substantial accelerations in glacier flow have been observed after lake drainage in Greenland60 and Alaska61. Although the subglacial hydrology of these glacierized regions remains unknown, these examples imply that Antarctic GLOFs could potentially trigger accelerations in ice flow. Therefore, more detailed measurements of the subglacial topography around the periphery of AIS are required to both elucidate potential GLOF triggers and map where ice-marginal lakes may form owing to the future retreat and/or thinning of AIS, as has been conducted in other glacierized regions62.The large-scale GLOFs that have been observed from ice-marginal lakes in Greenland64 due to subglacial freshwater discharge. Although the amount of freshwater that is discharged via LKI GLOF events is much less than the discharge in these modeling studies64, a sporadic freshwater pulse could promote a similar enhanced melt effect if the water discharges toward ice shelves. Nutrients and sediment transport are also expected owing to the freshwater transport, which may have an influence on nearby ocean ecosystems considering changes in the chemical properties of Antarctic ice-marginal lakes after GLOF events13. Although constraints on the subglacial discharge from AIS to the ocean are currently quite limited, such that the impact of this freshwater flux remains unknown, it is important to monitor such lake and freshwater transport to advance our understanding of this phenomenon along the periphery of AIS.Our results also imply the sporadic influx of freshwater to the ocean. However, our understanding of the freshwater supply from AIS to the surrounding ocean is currently limited. Recent modeling studies have shown that there is a limited contribution to the total basal melt of the ice shelves, with enhanced melt in sub-ice-shelf channels7 and (7.1 ± 0.4) × 107 m3 of water discharge during the 1969–1971 and 2017 GLOFs, respectively, which are two of the largest known GLOFs in Antarctica. Surface- and bed-elevation constraints have indicated that the GLOFs likely occurred via flotation of the ice dam, with water discharge occurring through a southerly drainage pathway from LKI. Furthermore, the 2017 GLOF occurred during the austral winter (April–May), thereby suggesting a year-round active subglacial hydrological network because there were no water inputs into LKI from surface processes.In this study, we revealed the occurrence of repeated GLOFs from LKI, an ice-dammed lake in East Antarctica, during the 1962–2021 period. Several types of data  were utilized to quantify the changes in lake-surface elevation and lake volume. We estimated (8.6 ± 1.5) × 10Our results, coupled with the lack of subglacial constraints in the region, emphasize the importance of elucidating the subglacial drainage system of AIS and highlight that continuous monitoring of ice-marginal lakes may provide important insights into AIS subglacial hydrology. Radar and/or seismic surveys are required to provide more accurate and detailed constraints on the subglacial topography and internal structure of ice dams. Therefore, our results will encourage future monitoring of Antarctic ice-marginal lakes and additional observations of AIS hydrological processes.https://www.gsi.go.jp/antarctic/06.html) for our time-series analysis. The spatial resolutions of the aerial photographs are 0.83–2.16 m. We also used optical satellite images acquired by the Landsat 1 Multispectral Scanner (MSS), Landsat 4 MSS/Thematic Mapper (TM), Landsat 5 MSS/TM, Landsat 8 Operational Land Imager (OLI), Sentinel-2 Multi Spectral Instrument (MSI), and Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) . The spatial resolutions of these satellite images are 60 m for MSS, 30 m for TM, 15 m for OLI and ASTER, and 10 m for MSI. False-color composite images were constructed using the red, green, and near-infrared band images that were included in each product. Note that we used pansharpened false-color Landsat 8 images, which were constructed using the Landsat 8 panchromatic images in the QGIS software.We analyzed aerial photographs and optical satellite images to delineate the surface features across LKI. JARE has acquired aerial photographs across Lützow-Holm Bay since 1957, with aerial photographs taken across the Skarvsnes region during the austral summers of 1957, 1962, 1969, 1971, 1983, 1992, 1993, and 2000. We obtained these freely available photographs, which were scanned at 400 dpi, from the Geospatial Information Authority of Japan  mounted on the Advanced Land Observing Satellite 2 (ALOS-2) satellite for this purpose. Radiometric calibrations, multi-looking , speckle reduction via the Refined Lee filter, and ellipsoidal corrections were applied to the Level 1.1 data (single-look complex) using the freely available Sentinel Applications Platform (SNAP) software developed by the European Space Agency. A terrain correction was then applied using the REMA-composite DEM in SNAP.The Landsat MSS and PALSAR-2 images possessed enormous horizontal geo-location errors (~ 2.4 km for MSS and ~ 300 m for PALSAR-2). We corrected these errors using the Georeferencer Plugin in the QGIS software and manually located ground control points (GCPs). Four GCPs were located within each image to determine their near-edge positions.We used five types of DEMs for the Skarvsnes region to retrieve the surface-elevation changes across LKI: SfM-DEMs, a GSI-DEM, an ALOS-DEM, REMA-DEMs, and a TDX-DEM.33 as follows. We first performed initial image matching, alignment, and three-dimensional (3-D) model reconstruction without any GCPs. We then extracted 53 GCPs from the 1993 DEM and orthoimage of the Skarvsnes region33 and manually located these GCPs on the aerial photographs  to the JARE aerial photographs to construct the SfM-DEMs. We first applied manual masking to eliminate the camera frames that were included in the periphery of the aerial photographs. We then followed the approach outlined in a previous study33. We also applied the photogrammetric tools in the Ames Stereo Pipeline software65 version 2.7.0 to the nadir and backward stereo-pair ALOS/PRISM images that were acquired on 19 November 2007 to construct a DEM.The GSI-DEM was constructed from a pair of 2.5-m resolution stereo images that were acquired on 18 January 2009 by the ALOS/Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM). GSI performed the DEM construction, which possessed a 10-m spatial resolution. The vertical accuracy of the GSI-DEM was evaluated to be 3.82 m based on a comparison of static geodetic survey constraints and the GSI-DEM elevations at a series of outcrops across the Skarvsnes region35 and other DEMs to investigate the recent surface-elevation changes across LKI. The REMA-DEMs were constructed by applying the photogrammetric tools in the SETSM software66 to panchromatic stereo images acquired by the WorldView-1/-2/-3 and GeoEye-1 satellites. We used 22 strip REMA-DEMs (version 4.1) to retrieve the surface-elevation changes across LKI. Each strip REMA-DEM was constructed from a pair of satellite stereo images and, therefore, possessed a precise acquisition date. The spatial resolutions of the original distributed strip REMA-DEMs are 2 m. We used the composite REMA-DEM as the reference DEM in this study because the composite REMA-DEM was constructed by mosaicking the strip REMA-DEMs and possessed a reliable vertical coordinate34. The spatial resolution of the composite REMA-DEM was 10 m, and the vertical accuracy was reported to be < 1 m34.We used the REMA-DEMshttps://www.eorc.jaxa.jp/ALOS/en/dataset/aw3d30/aw3d30_e.htm) to determine the precise orbits during the Bp estimation. The generated TDX-DEM was processed using the GAMMA software version 20220630.A TDX-DEM was generated from X-band SAR data that were acquired simultaneously by the TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X) and TerraSAR-X on 8 June 2017 during the bistatic operation mode. We applied interferometric SAR processing to the SAR data pair and then converted the obtained interferometric phase of each pixel to a surface height with a precisely determined perpendicular baseline length (Bp) between the two satellites. We used GCPs from AW3D30 version 3  from the original DEMs. We only applied horizontal shift and elevation-dependent bias corrections to the SfM-DEMs because the along-/across-satellite tracks were not determined for the SfM-DEMs. We then subtracted the second-order surfaces from the SfM-DEMs to remove any doming/bowl errors that are typically included in SfM-DEMs69. The surfaces were fitted via the least-squares method to the difference between each SfM-DEM and the reference DEM. Note that the TDX-DEM includes long-wavelength noise because the TDX-DEM was constructed via SAR interferometry of the TanDEM-X and TerraSAR-X satellites. We subtracted the noise by applying the least-square method to estimate the second-order surfaces after the elevation-dependent bias-removal correction. We corrected the ALOS-DEM by removing the horizontal shifts and elevation-dependent biases, and the GSI-DEM, SfM93-DEM, and strip REMA-DEMs by removing the vertical offsets. Finally, all of the DEMs were aligned to the grid of the reference DEM to yield DEMs with a consistent 10-m spatial resolution  contour in Fig. empty). REMAempty was acquired shortly after the lake drainage, when the lake level was low; therefore, it should represent the lake-bed geometry (Supplementary Fig. empty contour lines in the lake area represented the lake extent at an arbitrary elevation, such that the lake-surface elevation was determined by comparing the REMAempty contour lines and surface elevations in the optical satellite images. The elevation of the best-fit contour line was defined as the lake-surface elevation for the date when the satellite image was acquired. We iterated this procedure to determine the upper and lower elevation bounds, which were often different based on the features along the lake margin (Supplementary Fig. We also estimated the lake-surface elevation using the optical satellite imagery and the 1 October 2017 REMA-DEM (REMAempty. empty. The uncertainty in the lake-volume change We calculated the relative lake water volume 43 version 3.We investigated the possibility of the LKI ice dam reaching flotation. We used Eq.  to test Supplementary Information 1.Supplementary Information 2.Supplementary Information 3.


Acremonium egyptiacum, has been reported as a potential lead candidate for drug development against parasites and cancer. In this study, we demonstrated that AF and its derivatives are potent anthelminthic agents, particularly against Echinococcus multilocularis, which is the causative agent of alveolar echinococcosis. We measured the inhibitory activities of AF and its derivatives on the mitochondrial aerobic and anaerobic respiratory systems of E. multilocularis larvae. Several derivatives inhibited complex II  and also complex I to III , but not complex I (NADH:quinone reductase), indicating that mitochondrial complexes II and III are the targets. In particular, complex II inhibition in the anaerobic pathway was notable because E. multilocularis employs NADH:fumarate reductase (fumarate respiration), in addition to NADH oxidase (oxygen respiration), resulting in complete shutdown of ATP synthesis by oxidative phosphorylation. A structure-activity relationship study of E. multilocularis complex II revealed that the functional groups of AF are essential for inhibition. Binding mode prediction of AF derivatives to complex II indicated potential hydrophobic and hydrogen bond interactions between AF derivatives and amino acid residues within the quinone binding site. Ex vivo culture assays revealed that AF derivatives progressively reduced the viability of protoscoleces under both aerobic and anaerobic conditions. These findings confirm that AF and its derivatives are the first dual inhibitors of fumarate and oxygen respiration in E. multilocularis and are potential lead compounds in the development of anti-echinococcal drugs.Ascofuranone (AF), a meroterpenoid isolated from various filamentous fungi, including  Echinococcus multilocularis. This parasite is a public health concern throughout the Northern Hemisphere. Currently, albendazole is the only available chemotherapy for alveolar echinococcosis and shows insufficient efficacy , shows a synergic effect ex vivo and also in vivo when administered in combination with albendazole . Complexes I (NADH:quinone oxidoreductase) and II  transfer electrons from NADH and succinate, respectively, to complex III via the ubiquinone pool . The red in vivo . Fumaratthe host . Fumaratthe host .E. multilocularis protoscoleces, and both complex I and II have been suggested as drug targets , an enzyme that is essential for parasite survival   is a meroterpenoid compound produced by filamentous fungi, including yptiacum , 9. AF hsurvival –13. Recem burden . Furtherivation) , 16. It ivation) , 18. Recyptiacum , 20; theE. multilocularis. We examined the inhibitory activities of AF and its derivatives on the mitochondrial respiratory chain of E. multilocularis and evaluated their structure-activity relationship with complex II and their binding mode. In addition, we demonstrated the efficacy of AF derivatives against E. multilocularis protoscoleces in ex vivo assays under aerobic and anaerobic conditions.Here, we report novel pharmacological findings of AF and its derivatives, which could contribute to the development of anti-echinococcal drugs as well as elucidate mitochondrial function in 50 = 0.088 to 0.135 μM. The NADH:cytochrome c reductase activity by complexes I and III, was potently inhibited by AF derivatives, with IC50 values of 0.008 to 0.274 μM. As complex I is not inhibited by AF or its derivatives, the target of inhibition is complex III. Notably, several AF derivatives inhibited both complexes II and III, although the inhibitory activity for each complex differed according to the structure of the compounds.50 2-fold compared to the acetyl group (D6), indicating that the 1-acetyl group is more favorable than the 1-aldehyde group for inhibiting SQR activity. When the acetyl group (D6) or 1-aldehyde group (D7) was changed to a methyl ester group (D9), the inhibitory activity was lost (IC50 > 10 μM), suggesting that substituents bulkier than an acetyl group are deleterious for the inhibition of SQR activity. Next, the contribution of the 5-Cl group was evaluated. A comparison between D7 and D8 revealed that the 5-Cl group is essential for the inhibitory activity. However, when the 6-methyl group was removed from the benzene ring, the inhibitory activity was increased by 2- to 3-fold . In addition, when the 4-OH group in AF was changed to a methoxy group (as D11), the inhibitory activity was lost. The contribution of the 2-OH group for the inhibition of complex II could not be evaluated in this study because of difficulties in the synthesis of AF derivatives with substitutions only at this position.As the inhibition of complex II activity by AF and its derivatives can be examined directly, the structure-activity relationship of the compounds was examined. Structurally, AF is comprised of benzene, linker, and terminal groups . 50 = 0.95, 1.2, and 1.2 μM, respectively). In contrast, compounds with either a short linker  or the longest one (C12) exhibited a remarkable decrease in potency. Modifications of the linker group were also evaluated , D13 (two branched methyl groups), D14 (one branched methyl group), and D15  were 0.57, 0.28, 0.54, and 0.89 μM, respectively. The IC50 of D13 with two branched methyl groups was three times lower than that of D15, which had a linear alkyl chain.The effect of the linker length of AF derivatives on SQR inhibition was also evaluated. As shown in valuated . Four ty50 values decreasing to 0.30, 0.25, and 0.48 μM, respectively, compared with an IC50 of 1.1 μM for AF. However, IC50 was increased in several groups, such as D18 and 19.AF derivatives possessing changes in the terminal group were also evaluated . ChanginE. multilocularis complex II was performed using AlphaFold2    22)..E. multiE. multilocularis complex II, the entrance of the quinone binding site was narrowed by the presence of Phe73 at the SDHC subunit (Phe73C), which is replaced by glycine (Gly) in the corresponding subunit from A. suum complex II. Also, the calculated entrance sizes of the quinone binding sites of A. suum and E. multilocularis complex II are 11 × 11 and 6 × 11 Å, respectively. Because of the bulky side chain of the Phe73C residue, our prediction suggests that the quinone binding site of E. multilocularis cannot accommodate NN23 . These observations are further supported by the lack of inhibition of NN23 against E. multilocularis complex II (NN23 IC50>20 μM), although it strongly inhibited the A. suum enzyme at an extremely low concentration, NN23 IC50 = 0.005 μM . Conversely, D5 strongly inhibited complex II activity of E. multilocularis with an IC50 of 0.047 μM, while it showed 234-fold less potent inhibition (IC50 = 11 μM) against A. suum complex II activity . Fi. FiE. mumplex II .in vitro treatment with AF under both aerobic and anaerobic conditions. D2 completely eliminated the parasites by day 4 under aerobic culture conditions, while 6 days were required for complete elimination under anaerobic conditions. D4 showed an antiparasitic effect of only 34% elimination on day 7 under aerobic conditions, whereas 65% of the parasites were eliminated by day 7 under anaerobic culture conditions. D5 eliminated the parasites completely by day 6 and day 5 under aerobic and anaerobic conditions, respectively. Thus, D5 killed the parasites more effectively under hypoxia than normoxia.A culture assay with protoscoleces was performed under aerobic and anaerobic conditions with AF, D2, D4, and D5. As shown in E. multilocularis. Notably, we demonstrated that AF and its derivatives inhibited both complexes II and III of the mitochondrial electron transport chain at submicromolar to nanomolar levels, showing for the first time that simultaneous inhibition of the fumarate and oxygen respiration with a single compound can be achieved. In addition, several AF derivatives are particularly important because they potently inhibited E. multilocularis complex II, which is directly involved in the anaerobic respiration maintained by parasites inside the host.In this study, we investigated the effects of AF and its derivatives on the mitochondrial respiratory chain of E. multilocularis complex II, and can be summarized as follows: (i) the 1-acetyl group in the benzene ring improved the inhibition potency compared with a 1-aldehyde group; (ii) the length of the linker required for optimum inhibition was observed to range from C7 to C10, and linkers with two branched methyl groups were preferable; (iii) 5-chlorine is essential for inhibitory activity; and (iv) the 6-methyl group as well as the furanone ring are both dispensable for inhibition; however, depending on the substitution at the terminal group, the inhibitory activity can be increased.The structure-activity relationship of AF derivatives provided important information about the functional groups crucial for inhibition of E. multilocularis complex II. A critical role for the 4-OH group in inhibition seems to be a common trait between TAO, HsDHODH, and E. multilocularis complex II. Because the removal of the 5-chlorine from the benzene group causes the complete loss of inhibition activity, this group might have an essential interactive role through halogen bonding with εN1 from Trp197B, similar to what is observed in the cocrystal structures of HsDHODH with AF and its derivatives  than complex III (IC50 = 0.109 and 0.221 μM), respectively, showed high killing rates for protoscoleces under anaerobic conditions compared to aerobic conditions. Also, D2 inhibited E. multilocularis complex III with an IC50 value of 0.008 μM, whereas the IC50 value for complex II was 0.309 μM, which indicates that D2 shows a 38-fold higher selectivity for protoscoleces cultured under aerobic than anaerobic conditions. Interestingly, despite the relatively low inhibitory activity of AF against complex II (IC50 = 1.10 μM), it exhibited a strong killing effect under anaerobic conditions. This suggests that the furanone ring as the terminal group of AF might contribute to increased cell membrane permeability; however, further studies are required to confirm this hypothesis.In the culture assay, the time required to kill protoscoleces in aerobic and anaerobic conditions differed according to the ICE. multilocularis. The complete blockage of mitochondrial respiration can lead to a pleiotropic effect in the metabolism of all life cycle stages of E. multilocularis, including the collapse of the mitochondrial electrochemical gradient, ATP synthesis by oxidative phosphorylation (complex V), the NADH oxidation system (complex I), glycerol metabolism , and sulfide metabolism (sulfide:quinone oxidoreductase).Our findings demonstrate, for the first time, antiparasitic agents that can potently inhibit both fumarate and oxygen respiration in E. multilocularis under anaerobic conditions  and complex I by quinazoline can enhance the effect of ELQ-400 against the metacestodes of nditions . This efE. multilocularis (Nemuro strain) protoscoleces isolated from infected hispid cotton rats, Sigmodon hispidus, were used. The tissues were shredded through a metal mesh (0.5 mm diameter). Then, the tissues were repeatedly suspended and washed with physiological saline in a tall beaker to obtain protoscoleces by exploiting the buoyancy difference between protoscoleces and other tissue (g for 10 min (4°C) to remove cell debris and nuclei. The supernatant was then centrifuged at 8,000 × g for 10 min (4°C) to obtain the mitochondrial pellet. Next, the pellet was resuspended in mitochondrial preparation buffer  and centrifuged at 8,000 × g for 10 min (4°C). The enriched mitochondrial fraction was finally suspended in approximately 0.5 to 1.0 mL of mitochondrial preparation buffer without malonate and frozen at −50°C. The mitochondrial fraction from A. suum was prepared essentially as described previously . All surgeries were performed under anesthesia with sodium pentobarbital and isoflurane, and every effort was made to minimize suffering.c reductase activity (complexes II to III) were measured using a UV-3000 spectrophotometer  as described previously (−1 cm−1). The reagents used in the SQR activity assay were mixed with the reaction buffer containing 50 mM potassium phosphate (pH 7.4) and 0.1% (wt/vol) sucrose monolaurate . SQR activity was determined by monitoring the change in absorbance of quinone at 278 nm (ε = 15 mM−1 cm−1) in the presence of 60 μM decylubiquinone, 2 mM KCN, and the inhibitor. The reaction was initiated by the addition of 10 mM disodium succinate to the mixture. NADH:cytochrome c activity (complex I to III) was measured in the reaction buffer  containing 2 mM KCN, 50 μM cytochrome c , and the inhibitor. The assay was performed after the addition of 100 mM malonate to block complex II activity. The reaction was started by adding 50 μM NADH to the mixture, and the enzyme activity was determined by monitoring the change in absorbance of cytochrome c at 550 nm (ε = 19 mM−1 cm−1). IC50 values of AF and its derivatives against the specific activities of mitochondrial respiratory enzymes in protoscoleces were determined. The IC50 of each compound was determined by calculating approximation lines from three or more points on either side of the IC50 concentration.NADH:quinone reductase activity (complex I), succinate:quinone reductase activity (complex II), and succinate:cytochrome eviously , 6. BrieE. multilocularis mitochondrial complex II using AlphaFold2  in E. multilocularis complex II was predicted based on previous reports of the crystal structure of A. suum in complex with flutolanil (E. multilocularis complex II subunits were retrieved from the NCBI database using the following accession numbers: Fp (BAX90095.1), Ip (BAX90096.1), CybL (BAX90098.1), and CybS (BAX90099.1).We performed protein structure prediction for phaFold2 , 30. The reports –23. The utolanil , 31, 32.wt/vol) yeast extract , 2 mM l-glutamine (Gibco), 23 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, 0.5% (wt/vol) D (+)-glucose, 0.4 mM sodium taurocholate , 57 mM sodium hydrogen carbonate, and 100 U/mL penicillin-streptomycin (Gibco). The protoscoleces were observed daily for seven consecutive days, and half of the medium was replaced on day 3. For anaerobic cultures, six-well plates were sealed in plastic containers with oxygen-detecting agents and oxygen scavengers  to keep the oxygen concentration below 0.3% at 37°C. The protoscoleces were treated with AF and its derivatives at a final concentration of 50 μM in the culture medium, and the duration of parasite elimination was investigated. The control group was supplemented with 0.5% (vol/vol) dimethyl sulfoxide (DMSO), and all conditions were assayed in triplicate. We used ATV in a culture assay as positive control and to ensure anaerobic conditions in the culture  containing 0.5% . All statistical analyses were performed using EZR   .


The ability of motor-inhibitory control is critical in daily life. The physiological mechanisms underlying motor inhibitory control deficits remain to be elucidated. Beta band oscillations have been suggested to be related to motor performance, but whether they relate to motor-inhibitory control remains unclear. This study is aimed at systematically investigating the relationship between beta band oscillations and motor-inhibitory control to determine whether beta band oscillations were related to the ability of motor-inhibitory control.We studied 30 healthy young adults (age: 21.6 ± 1.5 years). Stop-signal reaction time (SSRT) was derived from stop signal task, indicating the ability of motor-inhibitory control. Resting-state electroencephalography (EEG) was recorded for 12 min. Beta band power and functional connectivity  were calculated. Correlations between beta band oscillations and SSRT were performed.P’s = 0.031, 0.021, 0.045, and 0.015, respectively). Beta band coherence between bilateral MC, SC, and IFC was also positively correlated with SSRT (P’s < 0.05). Beta band global efficiency was positively correlated with SSRT (P = 0.01).Beta band EEG power in left and right motor cortex (MC), right somatosensory cortex (SC), and right inferior frontal cortex (IFC) was positively correlated with SSRT (This is the first study to investigate the relationship between resting-state cortical beta oscillations and response inhibition. Our findings revealed that individuals with better ability of motor inhibitory control tend to have less cortical beta band power and functional connectivity. This study has clinical significance on the underlying mechanisms of motor inhibitory control deficits. Motor-inhibitory control refers to the ability that inhibits inappropriate motor responses and expresses more appropriate responses, which is considered as an important ability in daily life . The abiAs a common neuroimaging approach, electroencephalography (EEG) has been widely applied in the field of neurophysiological research. Ongoing spontaneous EEG oscillations are usually categorized into five frequency bands, including delta, theta, alpha, beta, and gamma bands. In particular, rhythmic activity in the beta band  is classically considered as being related to sensorimotor functions , but theFunctional connectivity stands for the synchrony of cortical activity in anatomically distinct but functionally collaborating brain regions . Unlike In present study, we investigated the relationship between beta-band oscillations and motor inhibitory control . We anticipated that beta band power, functional connectivity, and global efficiency would be positively correlated with SSRT. Our findings will have implications on understanding physiological mechanisms of motor inhibitory control deficits and possibly inform the development of new treatment for inhibitory control deficits.A total of 30 healthy adults  participated in this study. Written informed consent was obtained prior to enrollment. All procedures were approved by the Guangzhou First People’s Hospital Human Research Ethics Committee.Stop signal task was used to assess the ability of motor-inhibitory control . A 13.5-P ] close to 50%. The experiment included 24 practice trials and 400 experimental trials, consisting of 70% “Go” trials, 10% “Nogo” trials, and 20% “Stop” trials, administered in a completely random sequence. The details of SST were described in a previous paper  was increased by 50 ms on the next “Stop” trial. In the trials where inhibition failed, SSD was decreased by 50 ms on the next “Stop” trial. This ensured an overall successful rate of inhibition [i.e., us paper .P . Go omissions refers to Go trials on which the participants did not respond before the response deadline. In the cases of Go omissions, the SSRT was assigned with the maximum reaction time (RT)  to compensate for the lack of responses  in a geodesic pattern over the surface of the head with a vertex reference. It included 19 contacts at the equivalent 10–20 system locations. The EEG data were digitized and amplified at a 2,000 Hz sampling rate with a Geodesic EEG system 400 . An online bandpass filter (0.1–100 Hz) was applied and the impedance for the whole net was kept below 10 kΩ throughout data collection . The 12 Acquired EEG signal were analyzed off-line using MATLAB2019b . EEGLAB toolbox (version 14.1.2b) was used for EEG data preprocessing . After tPower and functional connectivity analyses were conducted using customed MATLAB scripts. Absolute power was calculated by fast Fourier transform and averaged in 13–30 Hz for beta band. As we were interested in assessing cortical activities in brain areas including inferior frontal cortex (IFC), motor cortex (MC), and somatosensory cortex (SC), six clusters of electrodes (three clusters for each hemisphere) were selected according to 10–20 system nomenclature . The aveCoherence was calculated using customed MATLAB scripts to reflect functional connectivity between different cortical regions. The Welch’s averaged, modified periodogram method , was perGRaph thEoretical Network Analysis (GRETNA) toolbox was used for graph theory analysis . A graphD is the shortest path length between node i and node j, and N is the number of nodes in the network.where P-values presented in current study are those after the false discovery rate correction. For all analyses, the statistical significance was set at P < 0.05.Statistical analysis was performed in Graphpad Prism (version 8.3.0). Data were found to meet the normality assumption using the Kolmogorov–Smirnov test. Pearson correlations were performed to investigate the relationship between physiological data and behavioral data . False discovery rate corrections were applied for multiple correlations. All Behavioral data of SST measures are summarized in r’s = 0.49, 0.52, 0.45, and 0.55, P’s = 0.031, 0.021, 0.045, and 0.015, respectively) (P’s > 0.05).ctively) , indicatP’s < 0.05) (P’s > 0.05). < 0.05) , 3. Therr = 0.59, P = 0.01) (P’s > 0.05).Our data revealed significant positive correlation between beta band global efficiency and SSRT ( = 0.01) . There wThis study investigated the relationship between resting state cortical beta activity and response inhibition. Our primary findings are (1) beta band EEG power in bilateral sensorimotor cortices and right inferior prefrontal cortex was positively correlated with SSRT; (2) beta band coherence between bilateral sensorimotor and inferior prefrontal cortices was positively correlated with SSRT; (3) beta band global efficiency was positively correlated with SSRT.Beta band power in bilateral sensorimotor cortices and right IFC was positively correlated with SSRT, suggesting that individuals with better ability of response inhibition tend to have less resting beta power. To our knowledge, no previous study has investigated the relationship between resting beta power and response inhibition. Prolonged SSRT has been observed in many psychiatric conditions with impaired urge control , such as attention deficit/hyperactivity disorder  and schiThe neural mechanisms underlying the relationship between beta band oscillatory activity and response inhibition remains unclear. Beta power has been suggested as a signature of an active process promoting the existing motor set whereas compromising neuronal processing of new movements . It has Unlike previous studies investigating the relationship between resting beta activity and velocity of voluntary movement  , our curInterestingly, we observed a significant correlation between SSRT and beta band power in bilateral sensorimotor cortex and right IFC, but not in the left IFC. Our results are in line with previous studies reporting that right IFC is an important structure for motor inhibitory control . As mostBoth beta band global efficiency and coherence between bilateral sensorimotor cortices and IFC were positively correlated with SSRT. Our findings suggest that in addition to beta band oscillatory activity, beta band functional connectivity also associates with response inhibition.Unlike EEG power reflecting oscillatory synchronization within local cortical neuronal populations, functional connectivity represents neuronal synchronization between distributed cortical regions . OscillaWe also observed the relationship between beta band global efficiency and the ability of response inhibition. Global efficiency exhibits the efficiency in transporting information at a global scale between genetic brain areas, and greater global efficiency reflects higher information transferring efficiency over the entire brain . Our resOur current study is the first study to investigate the relationship between resting-state cortical beta band activity and response inhibition. We observed positive correlations between beta band power, coherence and global efficiency and SSRT, indicating individuals with stronger cortical beta band activity tend to have worse ability of inhibitory motor control.Cortical beta band activity has been reported to be elevated in PD, and PD patients with greater beta band activity tend to have worse motor performance . As PD iDespite the extensive existing literature, there is still lack of solid evidence indicating the involvement of dopaminergic neurons in motor inhibitory control . SuppresN = 30). In addition, our sample includes only young adults, which is another limitation of current study. Cautions are needed when generalizing our findings to other populations, such as aging population and PD patients. Future studies are needed to test our results in other populations with larger sample sizes.As a pilot study, the sample size of current study is small (This is the first study to investigate the relationship between resting state cortical beta activity and response inhibition. This study revealed positive correlations between cortical beta band activity, coherence and global efficiency and SSRT, indicating individuals with less cortical beta band activity and functional connectivity tend to have better ability of motor inhibitory control. Our findings have implications on development of new treatment for the diseases with impaired motor inhibitory control.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Guangzhou First People’s Hospital Human Research Ethics Committee. The patients/participants provided their written informed consent to participate in this study.YL, HZ, and QD designed the experiment and wrote the manuscript. QD and TL recruited the participants. QD, GC, ZO, and SY conducted the experiments. QD and GC reduced, analyzed, and interpreted the data. All authors contributed to the article and approved the submitted version.