Modulating the Coordination Chemistry of Cobalt Catalytic Sites by Ruthenium Species to Accelerate the Polysulfide Conversion Kinetics in Lithium-Sulfur Batteries.

The performance of lithium-sulfur batteries is compromised by the loss of sulfur as dissolved polysulfides in the electrolyte and consequently the polysulfide redox shutting effect. Accelerating the conversion kinetics of polysulfide intermediates into sulfur or lithium sulfide through electrocatalysis has emerged as a root-cause solution. Co-N-C composite electrocatalyst is commonly used for this purpose. It is illustrated here that how the effectiveness can be improved by modulating the coordination chemistry of Co-N-C catalytic sites through introducing Ru species (RuCo-NC). The well-dispersed Ru in the Co-NC carbon matrix altered the total charge distribution over the Co-N-C catalytic sites and led to the formation of electron-rich Co-N, which is highly active for the polysulfide conversion reactions. Using Ru to modulate the electronic structure in the Co-N-C configuration and the additional catalytic sites over the Ru-Nx species can manifest optimal adsorption behavior of polysulfides. Consequently, the sulfur cathode with RuCo-NC can reduce the capacity fade rate from 0.11 % per cycle without catalyst (initial capacity of 701 mAh g-1) to 0.054 % per cycle (initial capacity of 1074 mAh g-1) over 400 cycles at 0.2 C rate. The results of this study provide the evidence for a feasible catalyst modification strategy for the polysulfide electrocatalysis.

Lipopolysaccharide inhibits osteoblast formation and receptor activator of nuclear factor-κB ligand degradation via autophagy inhibition.

Lipopolysaccharide (LPS) and Receptor Activator of Nuclear Factor-κB Ligand (RANKL) are the two important factors causing bone loss, which is an important pathogenesis for osteoporosis. However, the relationship between LPS and RANKL is not yet clear. LPS can be involved in the weakened osteoblast formation as an autophagy regulator, and osteoblasts and their precursors are the source cells for RANKL production. Our study aimed to explore the relationship between autophagy changes and RANKL production during LPS-regulated osteoblasts. Our results showed that LPS inhibited autophagy (LC3 conversion and autophagosome formation) and enhanced the protein and mRNA expression of RANKL in MC3T3-E1 osteoblast precursor line. Autophagy upregulation with Rapamycin over BECN1 overexpression rescued LPS-inhibited osteoblast formation and -promoted RANKL protein production in MC3T3-E1 cells. In vivo experiments supported that damaged bone mass, bone microstructure, osteoblastic activity (ALP and P1NP production by ELISA assays) and enhanced RANKL production by LPS administration were partially rescued by Rapamycin application. In conclusion, LPS can inhibit autophagy in osteoblast precursors, thereby inhibiting osteoblast formation and RANKL autophagic degradation.

Ternary Rotational Polyanion Coupling Enables Fast Li Ion Dynamics in Tetrafluoroborate Ion Doped Antiperovskite Li2OHCl Solid Electrolyte.

Li-rich antiperovskite (LiRAP) hydroxyhalides are emerging as attractive solid electrolyte (SEs) for all-solid-state Li metal batteries (ASSLMBs) due to their low melting point, low cost, and ease of scaling-up. The incorporation of rotational polyanions can reduce the activation energy and thus improve the Li ion conductivity of SEs. Herein, we propose a ternary rotational polyanion coupling strategy to fasten the Li ion conduction in tetrafluoroborate (BF4 -) ion doped LiRAP Li2OHCl. Assisted by first-principles calculation, powder X-ray diffraction, solid-state magnetic resonance and electrochemical impedance spectra, it is confirmed that Li ion transport in BF4 - ion doped Li2OHCl is strongly associated with the rotational coupling among OH-, BF4 - and Li2-O-H octahedrons, which enhances the Li ion conductivity for more than 1.8 times with the activation energy lowering 0.03 eV. This work provides a new perspective to design high-performance superionic conductors with multi-polyanions.

Accuracy and digital screw path design of TiRobot-assisted pedicle screw placement for lumbar spondylolisthesis.

PURPOSE: To investigate lumbar spondylolisthesis screw placement assisted by TiRobot in terms of digital screw path design, accurate implementation, and accuracy evaluation method. METHODS: In this study, we enrolled 40 patients with lumbar spondylolisthesis between December 2020 and August 2021 who underwent spine surgery at the Affiliated Hospital of PuTian University. Pre-operative computed tomography position and screw path designation, intra-operative pedicle screw placement according to pre-operative planning, and post-operative evaluation of the accuracy of screw placement were performed. 3D coordinates of the entry and exit points before and after the operation were collected. The qualified points at different levels of accuracy were counted. The screw placement accuracy was based on the absolute difference using the Chi-squared test. RESULTS: In total, 194 screws were successfully implanted with no screws penetrating the cortex. The absolute difference of entry points X, Y, and Z coordinates before and after the operation was 0.425 ± 0.294 mm, 0.417 ± 0.310 mm, and 0.466 ± 0.327 mm, respectively. The corresponding values in terms of exit points were 0.702 ± 0.470 mm, 0.963 ± 0.595mm, and 0.983 ± 0.566 mm, respectively. No obvious differences in coordinates before and after the operation were observed with an entry point degree of accuracy of ≥ 1.2 mm and exit point degree of accuracy of ≥ 2.1 mm. Therefore, the real surgery was consistent with the design. CONCLUSIONS: TiRobot-assisted lumbar spondylolisthesis surgery achieved optimal path designation and precise surgery.

Full-endoscopic foraminoplasty for highly down-migrated lumbar disc herniation.

BACKGROUND AND STUDY AIMS: Multiple surgical approaches have been studied and accepted for the removal of highly downward migrated lumbar disc herniation (LDH). Here, we investigated the efficacy and safety of full-endoscopic foraminoplasty for highly downward migrated LDH. PATIENTS AND METHODS: Thirty-seven patients with highly down-migrated LDH treated by the full-endoscopic foraminoplasty between January 2018 and January 2020 were retrospectively investigated. Clinical parameters were evaluated preoperatively and 1, 6, and 12 months postoperatively, using pre- and post-operative Oswestry Disability Index (ODI) scores for functional improvement, visual analog scale (VAS) for leg and back pain, and modified MacNab criteria for patients satisfactory. RESULTS: Thirty-seven patients with highly downward migrated LDH were successfully removed via the transforaminal full-endoscopic discectomy. The average VAS back and leg pain scores were significantly reduced from 7.41 ± 1.17 and 8.68 ± 1.06 before operation to 3.14 ± 0.89 and 2.70 ± 0.46 at postoperative 1 month, and 1.76 ± 0.59 and 0.92 ± 0.28 at postoperative 12 months, respectively (P < 0.05). The average ODI scores were reduced from 92.86 ± 6.41 to 15.30 ± 4.43 at postoperative 1 month, and 9.81 ± 3.24 at postoperative 12 months (P < 0.05). Based on the modifed MacNab criteria, 36 out of 37 patients (97.30%) were rated as excellent or good outcomes. CONCLUSION: The full-endoscopic foraminoplasty can be used successfully for surgical removal of high grade down-migrated LDH, and it could serve as an efficient alternative technique for patients with highly downward migrated LDH.

Accurate placement of cervical pedicle screws using 3D-printed navigational templates : An improved technique with continuous image registration.

OBJECTIVE: Accurate placement of cervical pedicle screws remains a surgical challenge. This study aimed to test the feasibility of using a novel three-dimensional (3D-)printed navigational template to overcome this challenge. METHODS: Cervical spines were scanned using computed tomography (CT). A 3D model of the cervical spines was created. The screw trajectory was designed to pass through the central axis of the pedicle. Thereafter, a navigational template was designed by removing the soft tissue from the bony surface in the 3D model. A 3D printer was used to print the navigational template. The screws were then placed in the cadavers following CT scanning. The 3D model of the designed trajectory and the placed screws were registered. The coordinates of the entry and exit points of the designed trajectory and the actual trajectory were recorded. The numbers of qualified points that met the different degrees of accuracy were compared using a χ2 test. RESULTS: A total of 158 screws were placed. Five screws breached the pedicle cortex with a distance <2 mm. There was no significant difference between the pre- and postoperative entry points with a degree of accuracy ≥1.7 mm (P = 0.131). Meanwhile, there was no significant difference between the pre- and postoperative exit points with degrees of accuracy ≥6.4 mm (P = 0.071). CONCLUSION: A navigational template can be designed by removing the soft tissue from the bony surface in a CT-generated 3D model. This guiding tool may effectively prevent intraoperative drifting and accurately places cervical pedicle screws.

Grass carp (Ctenopharyngodon idellus) invariant chain of the MHC class II chaperone protein associates with the class I molecule.

The invariant chain (Ii) is an important immune molecule, as it assists major histocompatibility complex (MHC) class II molecules to present antigenic peptides. The relationship between the Ii and MHC molecules in teleosts remains poorly understood. This study focused on the molecular structure of grass carp Ii (gIi), its organ distribution, correlations with gene transcription, and the association with MHC. gIi cDNA was cloned using designed degenerate primers and the rapid amplification of cDNA ends method (RACE). The gIi sequence was 92%-96% similar to that of other teleosts, but only 52%-67% similar to that of mammals, respectively. The gIi gene was distributed in all 12 organs examined by PCR. The gIi gene transcription levels were markedly higher in organs enriched with immune cells than in other organs (P < 0.01). Moreover, positive correlations were detected between transcription levels of the gIi and gMhcI or II genes in different organs (r = 8.415-8.523, P = 0.001). The gIi co-localized on endomembrane systems with either class I or II molecules in co-transfected cells observed by a laser confocal. Further testing confirmed that the gIi bound gMHCI and II molecules. Taken together, these results indicate that the gIi is associated with MHC class I and II molecules, suggesting homology of both MHC molecules.

Application of a novel 3D drill template for cervical pedicle screw tunnel design: a cadaveric study.

PURPOSE: To develop and validate the efficacy and accuracy of a three-dimensional (3D) computed tomography (CT) reconstructive rapid prototyping drill template for cervical pedicle screw placement. METHODS: CT thin-layer scans were obtained from 12 adult cadaveric cervical specimens and reconstructed. The ideal screw channels were chosen by analyzing the cross sections of the reconstructed 3D images. The navigation templates were designed and printed based on the optimal screw channels. The pedicle screws were placed on the cadaver specimens under template guidance, and the cadaver specimens were scanned and reconstructed. The pre- and post-operative models were compared. Entry point and exit point data of these two models were collected and compared using the Chi-square test. RESULTS: A total of 164 cervical pedicle screws were placed; among them, six punctured the cortical bone of the vertebral pedicle reaching an accuracy of 96.3%. Among the outside screws, all of the deviation distances were <2 mm. The Chi-square test results showed that when a deviation of 1.2 mm was used as a standard for the entry point, there was no difference between the two groups (χ 2 = 1.346, p = 0.248); when a deviation of 2.2 mm was used as a standard for the exit point, there was no difference between the two groups (χ 2 = 3.250, p = 0.061). CONCLUSION: The 3D CT reconstructive rapid prototyping drill template combined with the screw tunnel design based on 3D cutting technique can help facilitate accurate cervical pedicle screw insertion.

MicroRNA-320a protects against osteoarthritis cartilage degeneration by regulating the expressions of BMI-1 and RUNX2 in chondrocytes.

Osteoarthritis (OA) is one of the most common chronic degenerative diseases characterized by deterioration of articular cartilage. Many studies have demonstrated the role of microRNAs (miRNAs) in OA, but the role of miR-320a in OA remains elusive. The aim of this study was to identify the protective role of miR-320a in OA cartilage degeneration by regulating the expression of BMI-1 and RUNX-2 proteins in chondrocytes. Normal and OA chondrocytes obtained from patients were cultured in vitro. The chondrocytes (both normal and OA) were transfected with miR-320a inhibitor to investigate the effects of miR-320a on chondrocyte proliferation, and to identify the miR-320a target proteins. The results indicated that miR-320a expression was significantly higher (P<0.05) in OA chondrocytes than in normal chondrocytes. Inhibition of miR-320a effectively enhanced chondrocyte cell viability in vitro in a time-dependent manner. Inhibition of miR-320a showed a significant decrease (P<0.05) in the secretion of matrix metalloproteinase-13 (MMP-13). Furthermore, miR-320a could regulate the expression levels of BMI-1 and RUNX-2 proteins in OA chondrocytes (P<0.05). The data suggested that miR-320a protected against OA cartilage degeneration and regulated the expression levels of BMI-1 and RUNX2 proteins in chondrocytes. Our study might provide a new insight in the clinical treatment of OA.

[Digital design of internal fixation for distal femoral fractures via 3D printing and standard parts database].

OBJECTIVE: To study the method of internal fixation by the navigation embedded plate from standard parts database for the distal femoral fractures based on digital design by Mimics software with 3D printing technology, and to explore its feasibility and accuracy. METHODS: A total of 21 cases with distal femoral fractures admitted into the Department of Orthopedics, Affiliated Hospital of Putian University were included in this study. Dicom format data of lamellar CT scanning was imported into Mimics software for 3D anatomical modeling and virtual fracture reduction. The steel plates was chose from standard parts database for virtual internal fixation, and to design the navigation module with screw. 3D printing skeleton, steel plates, navigation module, internal fixation implants were simulated based on the printed bones model. Locations of steel plates and screws were determined by the navigation module. Then the sticking effects of navigation module, screws position and postoperative appearance were observed. After second CT scan and 3D reconstruction, 3D registration was performed to obtain the data of the three-dimensional coordinate values of screws entrance points and piercing points to analyze the results. RESULTS: A total of 21 plates and 180 screws were placed with the assistance of navigation module. CT scanning and 3D reconstruction was performed in twenty-one cases of postoperative bone model. The position of plates was in high accordance with the digital design by Mimics software. There were no significant differences between spatial location of screw entrance points and piercing points. The real operation was quite consistent with preoperative design. Navigation module and the corresponding distal femur bony structure jointed closely. The sticking effects and stability of navigation module were good, which was able to guide placement of steel plates and screws. CONCLUSION: These methods can enhance the accuracy of internal fixation of the standard parts database steel plate in distal femur fractures, with the assistance of navigation module.

Heat-fluid-solid coupling heat transfer analysis and parameter optimization in walnut drying device based on finite element method.

The moisture content of freshly picked walnuts is very high. In order to facilitate storage and transportation, it needs to be dried to prevent mildew. In this study, the pre-drying simulation and experimental study were carried out on the walnut drying equipment made by the research group to determine the optimal drying parameters. The effects of different inlet temperatures (353K, 373K, 393K), drying wind speeds (1.1 m/s, 1.4 m/s, 1.7 m/s) and drying time (30min, 45min, 60min) on the temperature and velocity fields of fluid and walnuts in the drying device were investigated by using the orthogonal test method of three factors and three levels. FLUENT software was used to simulate the drying process of open walnuts under hot air heating, and the distribution of fluid temperature field and velocity field in the drying device and the temperature change law of walnuts were obtained. The results show that when the inlet temperature is 393K, the inlet velocity is 1.7 m/s, and the drying time is 45min, the temperature field distribution of fluid and walnut in the drying device is the best and the change is the most uniform. In addition, the temperature change of the simulation results is consistent with the test results through experiments, which verifies the reliability of the simulation results. In order to more accurately simulate the change law of temperature and humidity transfer in hot air drying of walnuts, the walnut was modeled as a sphere consisting of three layers: walnut shell, air gap and walnut kernel. The reliability of the parameters was verified by surface response analysis. Taking inlet temperature, velocity and drying time as influencing factors and temperature change rate as evaluation index, the determination coefficient of regression model was R2 = 0.9966, and the correction determination coefficient Adj. R2 = 0.9922, indicating three influences. This study provides a theoretical basis for determining the optimum operating parameters of open walnut pre-drying, and has application value for walnut food processing.

Optimization design and analysis of mobile pump truck frame using response surface methodology.

In order to realize the lightweight design of mobile pump truck, this paper takes the frame of a certain type of mobile pump truck as the research object. The response surface method is used to carry out lightweight design of the longitudinal beam structure of the frame, and the finite element method is used to establish the finite element model to compare and analyze the optimized and original designs. The results show that the height, width and thickness of the optimized longitudinal beam section are reduced by 10mm, 11mm, and 0.8mm respectively, and the weight of the whole frame is reduced by 35.8kg. Before and after optimization, the displacement and stress changes of the frame are small in four motion situations, which meet the lightweight requirements of optimization design.

Ubiquitin-specific peptidases: Players in bone metabolism.

Osteoporosis is an ageing-related disease, that has become a major public health problem and its pathogenesis has not yet been fully elucidated. Substantial evidence suggests a strong link between overall age-related disease progression and epigenetic modifications throughout the life cycle. As an important epigenetic modification, ubiquitination is extensively involved in various physiological processes, and its role in bone metabolism has attracted increasing attention. Ubiquitination can be reversed by deubiquitinases, which counteract protein ubiquitination degradation. As the largest and most structurally diverse cysteinase family of deubiquitinating enzymes, ubiquitin-specific proteases (USPs), comprising the largest and most structurally diverse cysteine kinase family of deubiquitinating enzymes, have been found to be important players in maintaining the balance between bone formation and resorption. The aim of this review is to explore recent findings highlighting the regulatory functions of USPs in bone metabolism and provide insight into the molecular mechanisms governing their actions during bone loss. An in-deep understanding of USPs-mediated regulation of bone formation and bone resorption will provide a scientific rationale for the discovery and development of novel USP-targeted therapeutic strategies for osteoporosis.

Supplementation of hyaluronic acid injections with vitamin D improve knee function by attenuating synovial fluid oxidative stress in osteoarthritis patients with vitamin D insufficiency.

Objectives: There is still controversy about the effect of vitamin D supplementation on osteoarthritis (OA). The purpose of this study was to investigate the effects of vitamin D supplementation with Hyaluronic acid (HA) injection on OA. Methods: We investigated serum vitamin D levels and oxidative stress (OS) in synovial fluid from patients with OA who underwent total knee arthroplasty (grade IV, n = 24) and HA injection (grade II and III, n = 40). The effects of HA injection with or without oral vitamin D supplementation on synovial fluid OS and knee pain and function were then further investigated. Finally, patients underwent HA injection were divided into two groups according to vitamin D levels (vitamin D < or > 30 ng/ml), and the efficacy of the two groups were compared. Results: The results showed that the levels of glutathione peroxidase (GSH-PX) (P < 0.05) in the synovial fluid were lower in patients with stage IV OA than that in patients with stage II-III OA, while the levels of malondialdehyde (MDA) (P < 0.05) and lactate dehydrogenase (LDH) (P < 0.01) were significantly higher. Moreover, we found that age, BMI and vitamin D levels were significantly associated with the levels of oxidants and/or antioxidants in synovial fluid, and that vitamin D was significantly negatively correlated with BMI (R = -0.3527, p = 0.0043). Supplementation of HA injections with vitamin D significantly reduced the OS status in synovial fluid, attenuated knee pain and improved knee function in OA patients with vitamin D insufficiency. Conclusion: We conclude that maintenance of vitamin D sufficiency may be beneficial for the treatment of OA by improving OS in synovial fluid.

Integrative analysis of microRNA-320a-related genes in osteoarthritis cartilage.

Objectives: To investigate microRNA-320a-related differentially expressed genes (DEGs) and pathways in osteoarthritis (OA) by bioinformatic analysis. Methods: The target genes of microRNA-320a were searched and collected from MiRTarBase microRNA Targets dataset, the TargetScan Predicted Nonconserved microRNA Targets dataset and the TargetScan Predicted Conserved microRNA Targets dataset. OA-related microRNAs and OA-related target genes were collected from GeneCards databases. The pathway enrichment analysis of miRNAs ware performed by Funrich analysis tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was obtained from Database for Annotation, Visualization and Integrated Discovery (DAVID). GeneMANIA and STRING are used for protein-protein interaction (PPI) network analysis. Module analysis was performed by Cytoscape. Results: A total of 176 OA related miRNAs were searched and collected for enrichment analysis, and microRNA-320a was one of OA related miRNAs. Enrichment pathway and analysis of 1721 miRNA-320a-related target genes from MiRTarBase and TargetScan were performed using the online tools Metascape. And results shown that the biological processes were remarkably enriched in chromatin organization, cellular response to DNA damage stimuli, mRNA metabolic process, protein ubiquitination, and regulation of cell adhesion. And then we analysed miRNA-320a-targeted OA genes via KEGG, GO enrichment and PPI Network. Our results showed that miRNA-320a played a role in OA through FoxO signaling pathway, PI3K-Akt signaling pathway, focal adhesion, MAPK signaling pathway, HIF-1 signaling pathway and cellular senescence. And we speculate that MAPK signaling pathway plays a key role in the effect of miRNA-320a on OA. Conclusion: This study implied microRNA-320a-related DEGs and dysregulated pathways in OA. The aim is to screen miRNA-320a-related genes and pathways in OA and, eventually, to improve the understanding of underlying mechanisms of miRNA-320a in OA.

Feasibility Analysis of 3D Printing-Assisted Pedicle Screw Correction Surgery for Degenerative Scoliosis.

Objective: To explore the feasibility of 3D printing-assisted pedicle screw correction surgery for degenerative scoliosis. Methods: From January 1, 2015 to January 31, 2020, patients with degenerative scoliosis who received corrective surgery in our hospital were retrospectively analyzed. Patients were grouped based on the fixation methods. Patients in the control group received traditional pedicle screw internal fixation, while those in the study group received 3D printing-assisted pedicle screw fixation. The therapeutic effects were compared. Results: There were 78 cases in the control group and 82 cases in the study group. There were no significant differences in scoliotic Cobb's angle, pelvic incidence-lumbar lordosis (PI-LL), VAS score, JOA score, social function, physical function, role function, or cognitive function between the study group and the control group before the surgery, but there were differences in the above parameters between the two groups after surgery. The incidence of postoperative complications in the study group was also significantly lower in the study group. Conclusion: 3D printing-assisted pedicle screw correction surgery provides a strong 3D correction force with reliable effect and fewer complications, and is a good treatment choice for degenerative scoliosis.

Reduction with Pre-Drilling Combined with a Finger Reduction Tool in Difficult-to-Reduce Intertrochanteric Fracture.

OBJECTIVE: To investigate the feasibility of pre-drilling combined with a finger reduction tool for the reduction of difficult-to-reduce intertrochanteric fractures. METHODS: Patients diagnosed with complicated intertrochanteric fractures during the period from July 2016 to May 2021 at the Affiliated Hospital of our College were enrolled in this study. All patients underwent reduction by pre-drilling combined with a finger reduction tool followed by fixing with proximal femoral nail antirotation. The outcome of reduction was evaluated by intraoperative fluoroscopy. The operation time, intraoperative fluoroscopy frequency, and incidence of postoperative complications (including infection in the incision area, coxa vara, nail withdrawal, nail breakage, blade cut-out, lower limb vein thrombosis, and pulmonary embolism) were recorded to evaluate the speed of the operation, the difficulty of the operation, and the prognosis of the patient, respectively. The Harris hip score at 9 months after surgery was used to evaluate the hip recovery. RESULTS: A total of 52 patients (17 men and 35 women), 61-88 (77.54 ± 7.40) years of age were included in the study. There were 14 patients with cardiovascular or cerebrovascular disease, ten patients with diabetes, three patients with Parkinson's disease, and three patients with respiratory diseases. The fractures included in the study were classified according to the Orthopedic Trauma Association 31 classification system as type A2.2 (n = 36) or type A2.3 (n = 16). The time from injury to surgery was 1-11 (3.35 ± 1.78) days, and the operation time ranged 31-101 (65.67 ± 14.17) min. The intraoperative blood loss ranged from 40 to 100 (67.69 ± 18.24) mL, and the number of intraoperative fluoroscopy images obtained was 12 to 32 (20.42 ± 5.27). The Harris hip score at 9 months after surgery ranged from 84 to 94 (90.06 ± 2.15). Patients were followed for 9-16 (10.63 ± 1.61) months. One patient died of acute myocardial infarction at 9 months after surgery. One patient suffered from nail withdrawal 5 months post-operation and thus underwent hemiarthroplasty. CONCLUSIONS: Satisfactory reduction can be achieved using a pre-drilling femoral trochanter combined with a finger reduction tool for the management of difficult-to-reduce complex intertrochanteric fractures. This technique does not increase surgical trauma and also reduces the dose of radiation administered to the patient.

The causal relationship between obesity and skin and soft tissue infections: A two-sample Mendelian randomization study.

Objective: Many observational studies have shown that obesity strongly affects skin and soft tissue infections (SSTIs). However, whether a causal genetic relationship exists between obesity and SSTIs is unclear. Methods: A two-sample Mendelian randomization (MR) study was used to explore whether obesity is causally associated with SSTIs using a publicly released genome-wide association study (GWAS). An inverse-variance weighted (IVW) analysis was used as the primary analysis, and the results are reported as the odds ratios (ORs). Heterogeneity was tested using Cochran's Q test and the I2 statistic, and horizontal pleiotropy was tested using the MR-Egger intercept and MR pleiotropy residual sum and outlier (MR-PRESSO). Results: The results of the MR analysis showed a positive effect of BMI on SSTIs (OR 1.544, 95% CI 1.399-1.704, P= 5.86 × 10-18). After adjusting for the effect of type 2 diabetes (T2D) and peripheral vascular disease (PVD), the positive effect still existed. Then, we further assessed the effect of BMI on different types of SSTIs. The results showed that BMI caused an increased risk of impetigo, cutaneous abscess, furuncle and carbuncle, cellulitis, pilonidal cyst, and other local infections of skin and subcutaneous tissues, except for acute lymphadenitis. However, the associations disappeared after adjusting for the effect of T2D and PVD, and the associations between BMI and impetigo or cellulitis disappeared. Finally, we assessed the effects of several obesity-related characteristics on SSTIs. Waist circumference, hip circumference, body fat percentage, and whole-body fat mass, excluding waist-to-hip ratio, had a causal effect on an increased risk of SSTIs. However, the associations disappeared after adjusting for the effect of BMI. Conclusion: This study found that obesity had a positive causal effect on SSTIs. Reasonable weight control is a possible way to reduce the occurrence of SSTIs, especially in patients undergoing surgery.