Objective:Periprosthetic joint infection (PJI) is one of the most severe complications following hip and knee arthroplasty and is a leading cause of revision surgery. Pathogens and their antibiotic susceptibility are key factors in the successful treatment of PJI. This study retrospectively analyzes the pathogen characteristics and antimicrobial susceptibility of PJI patients treated at our center, aiming to establish an empirical antibiotic regimen for PJI in the region, providing a reference for empirical antibiotic therapy in the clinical management of PJI.Methods:This study retrospectively reviewed PJI patients treated at our center from January 2018 to October 2024. In each case, preoperative arthrocentesis fluid, and synovium tissue from at least three sites during surgery were collected for aerobic and anaerobic blood culture. The positive culture rate, distribution of pathogens based on Gram staining, methicillin resistance, mixed infections, and multidrug resistance were analyzed. Effective coverage parameters were constructed based on antimicrobial sensitivity and coverage rates, and appropriate empirical antimicrobial regimens were proposed.Results:A total of 233 PJI patients were included in the analysis. There were 99 males and 134 females with an average age of 67.0±10.1 years (ranging from 32 to 93 years). The study included 130 hip and 103 knee arthroplasty patients. Among the patients, 202 (86.7%) had positive cultures, with a total of 301 pathogen strains isolated: 268 Gram-positive bacteria (89.4%), 25 Gram-negative bacteria (8.3%), and 7 fungal strains (2.3%). The most common Gram-positive bacteria were coagulase-negative staphylococci (196 strains, 65.1%), epidermal staphylococci (77 strains, 25.6%), Staphylococcus aureus (39 strains, 13.0%), and Streptococcus spp. (19 strains, 6.3%). The most common Gram-negative bacteria were Enterobacteriaceae (14 strains, 4.7%). In hip joint infections, the most prevalent pathogens were epidermal Staphylococci (48 strains, 28.1%) and Staphylococcus aureus (27 strains, 15.8%), while in knee joint infections, epidermal Staphylococci (29 strains, 22.3%) were most common. Regarding antibiotic resistance, 48.5% of staphylococcal strains were methicillin-resistant Staphylococcus, and 51.5% were multidrug-resistant strains. Staphylococci were 100% susceptible to vancomycin, teicoplanin, daptomycin, linezolid, and tigecycline, but exhibited high resistance to β-lactams and quinolone antibiotics. Analysis of empirical antibiotic regimens revealed that vancomycin combined with meropenem, linezolid combined with meropenem, vancomycin combined with imipenem, vancomycin combined with piperacillin/tazobactam, and vancomycin combined with ceftriaxone had effective coverage rates of 97.0%, 97.0%, 96.0%, 94.9%, and 90.9%, respectively.Conclusion:The main pathogens in PJI in this region are Gram-positive bacteria, with high rates of methicillin resistance and multidrug resistance. Based on antimicrobial susceptibility data, we recommend vancomycin combined with meropenem as the empirical treatment regimen for culture-negative PJI in this region, with linezolid combined with meropenem as an alternative.

Objective:To evaluate the effectiveness of anti-G straining maneuver (AGSM) in pilots by surface electromyography (sEMG), and to explore the relationships between characteristics of sEMG and anti-G endurance in pilots.Methods:Thirty-eight male high-performance fighter pilots who completed the human centrifuge test at the Air Force Medical Center were selected. Among them, 25 completed the 8.0 G for 10 s anti-G endurance test and 13 completed the 9.0 G for 10 s anti-G endurance test. The sEMG tester was used to keep track of the changes of sEMG in rectus abdominis, rectus femoris, anterior tibial and gastrocnemius muscles while pilots were engaged in AGSM. The anti-G endurance was evaluated according to the changes of visual fields and consciousness. The pilots were divided into 3 groups: the good vision and consciousness group, peripheral visual field narrowing group and endurance endpoint group. The differences in the integral electromyogram (iEMG), mean power frequency (MPF) and muscle input rates between the 3 groups were investigated.Results:A total of 25 pilots completed the 8.0 G for 10 s anti-G endurance test. Among them, 8 (32.0%) were in the good vision and consciousness group, 13 (52.0%) in the peripheral visual field narrowing group and 4 (16.0%) reached the endurance endpoint. Among the 13 pilots who completed the 9.0 G for 10 s anti-G endurance test, 3 (23.1%) were in the good vision and consciousness group, 6 (46.1%) in the peripheral visual field narrowing group, and 4 (30.8%) in the endurance endpoint group. The results of sEMG showed that the iEMG values of the anterior tibialis muscle in pilots under the 9.0 G for 10 s load were significantly different across endurance groups ( H=7.54, P=0.023), and that the iEMG values of the tibialis anterior muscle in the good vision and consciousness group were higher than those in the endurance endpoint group ( P=0.036). The negative slopes of MPF for the rectus abdominis, rectus femoris, anterior tibialis, and gastrocnemius muscles were higher in the good vision and consciousness group than in the other 2 groups, but the differences were not statistically significant ( P>0.05). During the 8.0 G for 10 s anti-G endurance test, there were significant differences in lower limb muscle contribution rates between the 3 groups ( F=4.19, P=0.029). The endurance endpoint group exhibited a lower contribution rate than the good vision and consciousness group ( P=0.025). During the 9.0 G for 10 s anti-G endurance test, there were significant differences in tibialis anterior muscle contribution rates between the 3 groups ( F=4.16, P=0.049). The endurance endpoint group demonstrated a lower contribution rate than the good vision and consciousness group ( P=0.049). Conclusions:The full and balanced activation of abdominal muscles and lower limb muscles, especially the effective mobilization of calf muscles, plays a pivotal role in improving pilots′ AGSM efficiency in high G environments.

Objective:To find out whether the performance of a China-made high performance human centrifuge can satisfy the need of high G training by conducting physiological experiments.Methods:The dynamic physical performance of the anti-G equipment with the human centrifuge was tested before 5 subjects underwent the gradual-onset rate (GOR) run and rapid onset rate (ROR) run experiments. The G onset rate of GOR was 0.1 G/s. The relaxed G-tolerance under GOR (GOR tolerance 1) and the anti-G straining maneuver aided G-tolerance under GOR (GOR tolerance 2) were tested respectively. The G onset rate of ROR was 3 G/s, and the closed-loop mode and pre-programed mode were employed respectively. The closed-loop mode involved 5 G 10 s and 8 G 10 s, where the subjects were required to manipulate the joystick to ensure that the real-time curve of the load matched the target curve. In the pre-programmed mode, the subjects were exposed to 8 G 10 s passively, without any operation requirements. A subjective evaluation form was filled out by subjects after the experiments, in which the 14 indexes for evaluation were about the gondola facilities and environment, running processes, medical monitoring and overall assessment.Results:Both the oxygen mask and anti-G suit achieved full pressurization within 2.0 s. The GOR tolerance 1 was [4.0(3.8, 4.6)] G while the GOR tolerance 2 was (6.2±0.5) G, suggesting a statistically significant difference ( Z=-2.63, P=0.008). The HP anti-G straining maneuver effect was (2.0±0.6) G. All the 5 subjects finished the 5 G 10 s experiment in a closed-loop mode. Three of them attempted 8 G 10 s in the closed-loop mode (1 subject achieved only 7.6 G peak acceleration, and the other 2 achieved full 8 G 10 s exposure), while the remaining 2 completed the 8 G 10 s in the pre-programmed mode. In the closed-loop mode, it was found that the stick force was too strong, the guiding G and real time G curve were not easy to distinguish for some of the subjects because the curve colors were similar, and that the subjects could not see the G curves clearly in case of a grayout. Both seat comfort and the voice quality of communication got the highest subjective assessment score [5.0(4.0, 5.0)] while the sensation of tumble got the lowest score (2.8±0.8). The median or mean scores of other subjective evaluation indexes ranged from 3.0 to 4.6 points. The overall score of subjective assessment was [4.0(3.5, 4.0)] points. Conclusions:The China-made high performance human centrifuge can meet the requirements of 8.0 G high G training, which can be made more effective and comfortable if the strong stick force and feeling of tumble during stop running are overcome.

In recent years, the bacteriophage Φ29 (Phi29) DNA polymerase has garnered increasing attention due to its high-fidelity amplification capacity at constant temperatures. To advance the industrial application of this type of isothermal polymerases, this study mined and characterized new enzymes from the microbial metagenome based on the known Phi29 DNA polymerase sequence. The results revealed that a new enzyme, Php29 DNA polymerase, was identified in the microbial metagenome with plants as the hosts. This enzyme exhibited higher strand displacement activity, with a 59.5% similarity to bacteriophage Φ29. Experimental validation demonstrated that the enzyme had 3'→5' exonuclease activity, and its amplification products can serve as substrates for further catalytic reactions. The discovery and validation of Php29 DNA polymerase gives insights into the future industrial application of isothermal polymerases.
DNA-Directed DNA Polymerase/metabolism* ; Bacillus Phages/genetics* ; Metagenome

Background and Aims:Autoimmune thyroid disease(AITD)are closely associated with metabolic dysregulation,but the causal role of specific metabolites remains unclear.This study aimed to systematically evaluate the causal relationships between approximately 1 400 blood metabolites and two major AITD subtypes-Graves'disease(GD)and Hashimoto's thyroiditis(HT)-using a two-sample Mendelian randomization(MR)approach,to identify potential risk or protective metabolites and provide genetic evidence for mechanistic studies and targeted metabolic interventions.Methods:Summary-level genome-wide association study(GWAS)data for blood metabolites and AITDs were analyzed using inverse-variance weighted MR as the primary method,supplemented by MR-Egger,weighted median,and mode-based methods.Heterogeneity,pleiotropy,and robustness were assessed through Cochran's Q test,horizontal pleiotropy test,and leave-one-out analyses.Results:Forty-nine metabolites showed significant causal associations with GD and 89 with HT.Hexanoylglutamine and ceramide(d18∶1/16∶0)were identified as GD risk factors,while N2,N2-dimethylguanosine and β-hydroxyisovalerylcarnitine were protective.Pregnanediol sulfate and theobromine were associated with increased HT risk,whereas dihomo-linolenate(20:3n3 or n6)and caprylate appeared protective.The α-ketoglutarate/succinate ratio was positively associated with both diseases,suggesting a shared metabolic risk pathway.Conclusion:This MR study provides genetic evidence supporting causal links between multiple blood metabolites and GD or HT.Several metabolites may serve as predictive or protective biomarkers,offering novel insights into the pathophysiology,early screening,and personalized metabolic intervention strategies for AITDs.

Objective:Periprosthetic joint infection (PJI) is one of the most severe complications following hip and knee arthroplasty and is a leading cause of revision surgery. Pathogens and their antibiotic susceptibility are key factors in the successful treatment of PJI. This study retrospectively analyzes the pathogen characteristics and antimicrobial susceptibility of PJI patients treated at our center, aiming to establish an empirical antibiotic regimen for PJI in the region, providing a reference for empirical antibiotic therapy in the clinical management of PJI.Methods:This study retrospectively reviewed PJI patients treated at our center from January 2018 to October 2024. In each case, preoperative arthrocentesis fluid, and synovium tissue from at least three sites during surgery were collected for aerobic and anaerobic blood culture. The positive culture rate, distribution of pathogens based on Gram staining, methicillin resistance, mixed infections, and multidrug resistance were analyzed. Effective coverage parameters were constructed based on antimicrobial sensitivity and coverage rates, and appropriate empirical antimicrobial regimens were proposed.Results:A total of 233 PJI patients were included in the analysis. There were 99 males and 134 females with an average age of 67.0±10.1 years (ranging from 32 to 93 years). The study included 130 hip and 103 knee arthroplasty patients. Among the patients, 202 (86.7%) had positive cultures, with a total of 301 pathogen strains isolated: 268 Gram-positive bacteria (89.4%), 25 Gram-negative bacteria (8.3%), and 7 fungal strains (2.3%). The most common Gram-positive bacteria were coagulase-negative staphylococci (196 strains, 65.1%), epidermal staphylococci (77 strains, 25.6%), Staphylococcus aureus (39 strains, 13.0%), and Streptococcus spp. (19 strains, 6.3%). The most common Gram-negative bacteria were Enterobacteriaceae (14 strains, 4.7%). In hip joint infections, the most prevalent pathogens were epidermal Staphylococci (48 strains, 28.1%) and Staphylococcus aureus (27 strains, 15.8%), while in knee joint infections, epidermal Staphylococci (29 strains, 22.3%) were most common. Regarding antibiotic resistance, 48.5% of staphylococcal strains were methicillin-resistant Staphylococcus, and 51.5% were multidrug-resistant strains. Staphylococci were 100% susceptible to vancomycin, teicoplanin, daptomycin, linezolid, and tigecycline, but exhibited high resistance to β-lactams and quinolone antibiotics. Analysis of empirical antibiotic regimens revealed that vancomycin combined with meropenem, linezolid combined with meropenem, vancomycin combined with imipenem, vancomycin combined with piperacillin/tazobactam, and vancomycin combined with ceftriaxone had effective coverage rates of 97.0%, 97.0%, 96.0%, 94.9%, and 90.9%, respectively.Conclusion:The main pathogens in PJI in this region are Gram-positive bacteria, with high rates of methicillin resistance and multidrug resistance. Based on antimicrobial susceptibility data, we recommend vancomycin combined with meropenem as the empirical treatment regimen for culture-negative PJI in this region, with linezolid combined with meropenem as an alternative.

Background and Aims:Autoimmune thyroid disease(AITD)are closely associated with metabolic dysregulation,but the causal role of specific metabolites remains unclear.This study aimed to systematically evaluate the causal relationships between approximately 1 400 blood metabolites and two major AITD subtypes-Graves'disease(GD)and Hashimoto's thyroiditis(HT)-using a two-sample Mendelian randomization(MR)approach,to identify potential risk or protective metabolites and provide genetic evidence for mechanistic studies and targeted metabolic interventions.Methods:Summary-level genome-wide association study(GWAS)data for blood metabolites and AITDs were analyzed using inverse-variance weighted MR as the primary method,supplemented by MR-Egger,weighted median,and mode-based methods.Heterogeneity,pleiotropy,and robustness were assessed through Cochran's Q test,horizontal pleiotropy test,and leave-one-out analyses.Results:Forty-nine metabolites showed significant causal associations with GD and 89 with HT.Hexanoylglutamine and ceramide(d18∶1/16∶0)were identified as GD risk factors,while N2,N2-dimethylguanosine and β-hydroxyisovalerylcarnitine were protective.Pregnanediol sulfate and theobromine were associated with increased HT risk,whereas dihomo-linolenate(20:3n3 or n6)and caprylate appeared protective.The α-ketoglutarate/succinate ratio was positively associated with both diseases,suggesting a shared metabolic risk pathway.Conclusion:This MR study provides genetic evidence supporting causal links between multiple blood metabolites and GD or HT.Several metabolites may serve as predictive or protective biomarkers,offering novel insights into the pathophysiology,early screening,and personalized metabolic intervention strategies for AITDs.

Objective:To evaluate the effectiveness of anti-G straining maneuver (AGSM) in pilots by surface electromyography (sEMG), and to explore the relationships between characteristics of sEMG and anti-G endurance in pilots.Methods:Thirty-eight male high-performance fighter pilots who completed the human centrifuge test at the Air Force Medical Center were selected. Among them, 25 completed the 8.0 G for 10 s anti-G endurance test and 13 completed the 9.0 G for 10 s anti-G endurance test. The sEMG tester was used to keep track of the changes of sEMG in rectus abdominis, rectus femoris, anterior tibial and gastrocnemius muscles while pilots were engaged in AGSM. The anti-G endurance was evaluated according to the changes of visual fields and consciousness. The pilots were divided into 3 groups: the good vision and consciousness group, peripheral visual field narrowing group and endurance endpoint group. The differences in the integral electromyogram (iEMG), mean power frequency (MPF) and muscle input rates between the 3 groups were investigated.Results:A total of 25 pilots completed the 8.0 G for 10 s anti-G endurance test. Among them, 8 (32.0%) were in the good vision and consciousness group, 13 (52.0%) in the peripheral visual field narrowing group and 4 (16.0%) reached the endurance endpoint. Among the 13 pilots who completed the 9.0 G for 10 s anti-G endurance test, 3 (23.1%) were in the good vision and consciousness group, 6 (46.1%) in the peripheral visual field narrowing group, and 4 (30.8%) in the endurance endpoint group. The results of sEMG showed that the iEMG values of the anterior tibialis muscle in pilots under the 9.0 G for 10 s load were significantly different across endurance groups ( H=7.54, P=0.023), and that the iEMG values of the tibialis anterior muscle in the good vision and consciousness group were higher than those in the endurance endpoint group ( P=0.036). The negative slopes of MPF for the rectus abdominis, rectus femoris, anterior tibialis, and gastrocnemius muscles were higher in the good vision and consciousness group than in the other 2 groups, but the differences were not statistically significant ( P>0.05). During the 8.0 G for 10 s anti-G endurance test, there were significant differences in lower limb muscle contribution rates between the 3 groups ( F=4.19, P=0.029). The endurance endpoint group exhibited a lower contribution rate than the good vision and consciousness group ( P=0.025). During the 9.0 G for 10 s anti-G endurance test, there were significant differences in tibialis anterior muscle contribution rates between the 3 groups ( F=4.16, P=0.049). The endurance endpoint group demonstrated a lower contribution rate than the good vision and consciousness group ( P=0.049). Conclusions:The full and balanced activation of abdominal muscles and lower limb muscles, especially the effective mobilization of calf muscles, plays a pivotal role in improving pilots′ AGSM efficiency in high G environments.

Objective:To find out whether the performance of a China-made high performance human centrifuge can satisfy the need of high G training by conducting physiological experiments.Methods:The dynamic physical performance of the anti-G equipment with the human centrifuge was tested before 5 subjects underwent the gradual-onset rate (GOR) run and rapid onset rate (ROR) run experiments. The G onset rate of GOR was 0.1 G/s. The relaxed G-tolerance under GOR (GOR tolerance 1) and the anti-G straining maneuver aided G-tolerance under GOR (GOR tolerance 2) were tested respectively. The G onset rate of ROR was 3 G/s, and the closed-loop mode and pre-programed mode were employed respectively. The closed-loop mode involved 5 G 10 s and 8 G 10 s, where the subjects were required to manipulate the joystick to ensure that the real-time curve of the load matched the target curve. In the pre-programmed mode, the subjects were exposed to 8 G 10 s passively, without any operation requirements. A subjective evaluation form was filled out by subjects after the experiments, in which the 14 indexes for evaluation were about the gondola facilities and environment, running processes, medical monitoring and overall assessment.Results:Both the oxygen mask and anti-G suit achieved full pressurization within 2.0 s. The GOR tolerance 1 was [4.0(3.8, 4.6)] G while the GOR tolerance 2 was (6.2±0.5) G, suggesting a statistically significant difference ( Z=-2.63, P=0.008). The HP anti-G straining maneuver effect was (2.0±0.6) G. All the 5 subjects finished the 5 G 10 s experiment in a closed-loop mode. Three of them attempted 8 G 10 s in the closed-loop mode (1 subject achieved only 7.6 G peak acceleration, and the other 2 achieved full 8 G 10 s exposure), while the remaining 2 completed the 8 G 10 s in the pre-programmed mode. In the closed-loop mode, it was found that the stick force was too strong, the guiding G and real time G curve were not easy to distinguish for some of the subjects because the curve colors were similar, and that the subjects could not see the G curves clearly in case of a grayout. Both seat comfort and the voice quality of communication got the highest subjective assessment score [5.0(4.0, 5.0)] while the sensation of tumble got the lowest score (2.8±0.8). The median or mean scores of other subjective evaluation indexes ranged from 3.0 to 4.6 points. The overall score of subjective assessment was [4.0(3.5, 4.0)] points. Conclusions:The China-made high performance human centrifuge can meet the requirements of 8.0 G high G training, which can be made more effective and comfortable if the strong stick force and feeling of tumble during stop running are overcome.

Objective:To evaluate the 1-year postoperative efficacy and nutritional indicators of single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) in obese patients.Methods:This retrospective observational study included patients with a body mass index (BMI) of ≥40.0 kg/m 2 regardless of other related metabolic diseases and patients with severe type 2 diabetes and a BMI between 27.5 and 40.0 kg/m 2. The clinical data of 66 obese patients who underwent SADI-S at the Bariatric and Metabolic Surgery Department of China-Japan Union Hospital of Jilin University from November 2018 to May 2022 were collected, including 53 cases of da Vinci robotic surgery and 13 cases of laparoscopic surgery. The patients comprised 38 men and 28 women with a median age of 35 (18–61) years and a mean preoperative BMI of 42.93 ± 6.82 kg/m 2. A total of 38 patients had type 2 diabetes, and 46 had hyperuricemia, 45 had hypertension, 35 had hyperlipidemia, 12 had hypercholesterolemia, and 12 had a high low-density lipoprotein (LDL) level. The main observation indicators were (1) intraoperative and postoperative conditions; (2) weight loss outcomes, including body weight, BMI, excess body weight loss (%EWL), and total body weight loss (%TWL) at 3, 6, and 12 months after surgery; (3) effects of treatment on metabolic disease; and (4) changes in nutrient indicators. Results:(1) Intraoperative and postoperative conditions: All patients successfully underwent SADI-S with neither conversion to laparotomy nor death. Four (6.1%) patients developed postoperative complications, and all of them recovered and were discharged after conservative or surgical treatment. (2) Weight loss outcomes: %EWL at 3, 6, and 12 months after surgery was 62.07 ± 26.56, 85.93 ± 27.92, and 106.65 ± 29.65, respectively, and %TWL was 22.67 ± 4.94, 32.10 ± 5.18, and 40.56 ± 7.89, respectively. Body weight and BMI 3 to 12 months after surgery were significantly lower than those before surgery (all P < 0.001). (3) Effect of treatment on metabolic disease: 3 to 12 months after surgery, fasting blood sugar, HbA1c, uric acid, systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, LDL, and other indicators were significantly lower than those before surgery (all P < 0.05). Twelve months after surgery, the remission rates of diabetes, hyperuricemia, hypertension, hypertriglyceridemia, hypercholesterolemia, and high LDL were 100% (38/38), 65.2% (30/46), 62.2% (28/45), 94.3% (33/35), 100% (12/12), and 100% (12/12), respectively. (4) Changes in nutrient indicators: Compared with the preoperative nutrient levels, the hemoglobin and hematocrit levels were lower at 3 to 12 months after surgery, the total protein level was lower at 6 to 12 months after surgery, the albumin level was lower at 6 months after surgery, and the ferritin level was lower at 3 months after surgery. The differences were statistically significant (all P < 0.05). The incidence of anemia was 6.1% (4/66), hypoalbuminemia was 4.5% (3/66), and ferritin deficiency was 4.5% (3/66), all of which were improved or normalized through conservative treatment. Twelve months after surgery, 30 (45.5%) patients had vitamin A deficiency, 17 (25.8%) had vitamin E deficiency, 11 (16.7%) had folic acid deficiency, 2 had potassium deficiency (3.0%), 3 (4.5%) had calcium deficiency, 2 (3.0%) had magnesium deficiency, 9 (13.6%) had iron deficiency, and 16 (24.2%) had zinc deficiency. However, no relevant clinical symptoms occurred. Conclusions:SADI-S has a very significant effect on weight loss and alleviation of metabolic diseases. Nutrient deficiencies after SADI-S mainly involve vitamin A, vitamin E, zinc, and folic acid. The long-term efficacy and safety of SADI-S still need further follow-up observation.