Tropical diseases, the transmission of which is affected by multiple natural and social factors, pose a great challenge to global public health, notably in African countries. During the past several decades, China and African countries have continuously collaborated for the control of neglected tropical diseases and malaria, which has become an important part of global South-to-South cooperation and global health governance. This article reviews the history of China-Africa cooperation for tropical diseases control, summarizes the experiences and achievements over the past decade, analyzes the current challenges in the coopera tion, and proposes future recommendations. The China-Africa cooperation has achieved significant progress in the control of tropical diseases, such as malaria, schistosomiasis, and filariasis, and established a China-Africa cooperation network for tropical diseases control. Through the "Three-Step" strategy of China-Africa cooperation, the effectiveness of China's integrated control strategies has been validated in Africa, and the application of China's tropical disease control technologies has been promoted in African disease-epidemic countries. Currently, China-Africa collaboration, however, still experiences multiple realistic challenges, such as insufficient resources, difficulty in technology transfer, and weak primary healthcare systems. In the future, both sides are recommended to further strengthen policy coordination, deepen technological cooperation, innovate cooperation models, aiming to continuously promote the high-quality development of China-Africa cooperation for tropical diseases control.

ObjectiveTo investigate the role of interleukin （IL）-17A in acute inhalational pneumonia induced by the highly drug-resistant and hypervirulent Staphylococcus aureus strain USA300-R in mice. MethodsAn acute inhalational pneumonia model was established in mice using an aerosolized pulmonary delivery technique. RNA sequencing （RNA-seq） and enzyme-linked immunosorbent assay （ELISA） were employed to examine the expression dynamics of Il17a mRNA and IL-17A protein， respectively， in the lungs of infected mice. Il17a knockout （Il17a^-/-） mice were generated using CRISPR/Cas9 gene editing technology. The survival rate， body weight， bacterial load in lung tissue， and histopathological changes were compared between Il17a^-/- and wild-type （WT） mice following inhalational infection with USA300-R. Results12 hours after USA300-R infection， compared to pre-infection， the expression level of Il17a mRNA in lung tissue and the level of IL-17A protein in bronchoalveolar lavage fluid （BALF） increased by approximately 50-fold （P<0.01） and 6-fold （P<0.001）， respectively. Compared to WT mice， Il17a^-/- mice exhibited approximately 10-fold higher bacterial loads in lung tissue at both 12 and 24 hours post-infection （P<0.001， P<0.05）. However， they showed significantly attenuated lung histopathological injury， reduced alveolar wall thickening， markedly decreased neutrophil infiltration， and an approximately 50% improvement in survival rate （P<0.05）. ConclusionIn acute Staphylococcus aureus USA300-R inhalational pneumonia， IL-17A contributes to bacterial clearance by recruiting neutrophils； however， excessive neutrophil infiltration exacerbates pulmonary inflammation and injury， reduces survival rates， and represents a potential therapeutic target.

Objective To explore the effect of frequency-modulated temporal interference electrical fields stimulation(TIs)on muscle strength and neuromuscular recruitment ability.Methods Sixteen healthy adult participants completed two testing sessions,with an interval of no less than 48 hours be-tween them.The only difference between them was the intervention of real TIs versus sham stimula-tion.The stimulation targeted the left primary motor cortex.During the test,the 3-second maximal vol-untary contraction(3 s MVC)of the first dorsal interosseous(FDI)muscle and the 20-second one(20 s MVC)in the right hand were recorded.Meanwhile,the surface electromyography(sEMG)sig-nals were recorded during the 20 s MVC and analyzed using sEMG decomposition techniques.Results A significant interaction effect was observed in peak muscle force during the 3 s MVC(P<0.05).Com-pared to baseline,real TIs significantly increased peak force,whereas the sham stimulation resulted in a decrease.Moreover,a significant interaction was also found in the peak EMG amplitude during the 20 s MVC(P<0.05),with peak EMG amplitude increasing after real TIs but decreasing after sham stimulation.Conclusion Frequency-modulated TIs effectively enhances peak muscle strength dur-ing the 3 s MVC and increases motor unit synchronization firing during the 20 s MVC.Therefore,TIs has potential for improving neuromuscular performance.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To explore the differences in muscle synergies of healthy individuals,intact limbs and residual limbs of above-knee amputees under different gaits,provide references for electromyographic control of the prosthetics.Methods Surface electromyography(sEMG)signals of 7 muscles(4 thigh muscles,3 calf muscles)were collected from 7 healthy individuals and 3 lower-limb amputees during level walking,ascending/descending slopes,and ascending/descending stairs.Muscle synergy weights(W)and temporal activation coefficients(H)were extracted using concatenated non-negative matrix factorization(CNMF).The W matrices were compared using the coefficient of determination R2,and the activation coefficients were analyzed using statistical parametric mapping(SPM).Furthermore,peak activation and activation integral were used for hierarchical clustering analysis.Results The comparison of W matrices indicated a similar set of muscle synergies between the healthy group and the intact limb of amputees,whereas the residual limb showed greater variability in synergies.The analysis of H showed statistically significant differences in muscle activation throughout the gait cycle for all amputees.Clustering of time-domain features revealed that amputees exhibited higher activation integral and peak values in their intact limb during ascending slopes.Conclusions This study provides an in-depth investigation of the neuromuscular compensation strategies in lower-limb amputees under different gaits,offering theoretical insights for gait rehabilitation and assisting in the development of EMG-controlled prosthetics.

Objective To explore the effect of different ways of out-of-plane shield on the tube current and cumulative radiation dose of CT scan.Methods The CT water membrane was scanned using Philips 128 row iCT scanner in different scanning methods:the 1-3 times,without the out-of-plane shield,the total length of localizer was 150 mm,270 mm,and 390 mm,respectively;the fourth time,the out-of-plane shield was used but was not present in the localizer;from the 5th to 7th pass,with out-of-plane shield and develop it in the localizer,with out-of-plane shield development lengths of 60 mm,180 mm,and 300 mm,respectively,and the out-of-plane shield was not within the formal scanning range.The tube current and cumulative radiation dose of various scanning methods were compared and a line graph of the tube current for scanning each layer was figured.Results(1)There was no statistically significant difference in tube current when there was no out-of-plane shield but the length of the localizer was different(P＞0.05).(2)When the pitch was 0.8,1.0,and 1.15 respectively,with out-of-plane shield but no shield object in the localizer,the scanning tube current was lower than that without shield scanning(P＜0.05).(3)When scanning with three different lengths of out-of-plane shield(60 mm,180 mm,300 mm)in the localizer,regardless of the pitch,the tube current was greater than that of unshield scanning(P＜0.05).(4)When there was a shield in the localizer,the closer to the shield,the higher the tube current in the formal scan.(5)The cumulative dose of scans with out-of-plane shield but without the presence of shield in the localizer was smaller than that of unshield scanning.However,with shield and the presence of shield scanning in the localizer,the cumulative radiation dose was greater than that of unshield scanning.Conclusion The presence of out-of-plane shield in the localizer may increase the tube current and radiation dose for formal scanning,and the closer to the shield,the more significant the increase in tube current.

Objective To analyze the correlation of serum levels of GAT A-binding protein 3(GATA-3),T cell immunoglobulin domain and mucin domain protein-3(Tim-3)and retinoid-related orphan nuclear receptor gamma t(RORγt)with cardiac function and myocardial injury in-dicators in patients with coronary heart disease(CHD)and angina pectoris.Methods A retrospec-tive analysis was performed on 120 CHD patients with angina pectoris(observation group)in our hospital from December 2020 to December 2023.They were divided into stable angina subgroup(53 cases)and unstable angina subgroup(67 cases)according to the results of electrocardiography and coronary angiography.Another 120 healthy individuals taking physical examination in our hospital during the same period were subjected and served as the control group.ELISA was used to detect the serum levels of GATA-3,Tim-3 and RORγt.Left ventricular ejection fraction(LVEF),left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD),and left ventricular short-axis shortening rate(FS)were measured by echocardio-graphy.Creatine kinase(CK)and creatine kinase isoenzyme(CK-MB)were detected by biochemi-cal analyzer,and troponin Ⅰ(cTnⅠ)and heart fatty acid binding protein(H-FABP)were detected by electrochemiluminescence immunoassay.Pearson analysis was applied to analyze the correlation the correlation of serum levels of GATA-3,Tim-3 and RORγt with cardiac function and myocar-dial injury indicators.ROC curve was plotted to analyze the predictive value of the above three in-dicators for unstable angina.Results The serum levels of Tim-3 and ROR y t were significantly higher,and that of GATA-3 was obviously lower in the observation group than the control group(397.14±78.42 ng/L vs 246.45±56.81 ng/L,P＜0.01;93.18±19.94 ng/L vs 35.72±7.79 ng/L,P＜0.01;38.21±9.45 ng/L vs 71.62±14.98 ng/L,P＜0.01).The LVEDD and LVESD values were notably higher,while the LVEF and LVFS values were remarkably lower in the observation group than the control group(P＜0.01).The observation group has statistically higher cTnⅠ,CK,CK-MB,and H-FABP levels than the control group(P＜0.01).In the CHD patients with angina pectoris,serum GATA-3 level was positively correlated with LVEF and LVFS,and negatively with LVEDD,LVESD,cTnⅠ,CK,CK-MB,and H-FABP;Tim-3 and RORγt were negatively corre-lated with LVEF and LVFS,and positively with LVEDD,LVESD,cTnⅠ,CK,CK-MB,and H-FABP(P＜0.01).The AUC value of GATA-3,Tim-3,and RORγt alone and in combination in predicting unstable angina was 0.859,0.827,0.780,and 0.921,respectively,with that of combina-tion significantly higher than that of above indicators alone(Z=1.993,3.021,4.532,P=0.036,0.007,0.001).Conclusion As the disease progresses in CHD patients with angina pectoris,serum levels of Tim-3 and RORγt are increasing,while that of GATA-3 is decreasing,and all of them are closely associated with heart function and myocardial injury indicators.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective·To construct an interpenetrating network hydrogel(HMGL)that can induce hypoxia in situ,investigate its effects on promoting the secretion of extracellular matrix in nucleus pulposus cells(NPCs),and evaluate its potential in the treatment of intervertebral disc degeneration.Methods·HMGLs capable of long-term in situ hypoxia induction were prepared by a two-step polymerization method.Hypoxic hydrogels with laccase concentrations of 5 U/mL and 10 U/mL,namely HMGL-5 and HMGL-10,were constructed,whereas a hyaluronic acid methacryloyl(HAMA)hydrogel served as the control.The molecular structures of HAMA and gelatin grafted with vanillin(GelVA)were verified by 1H nuclear magnetic resonance spectra(1H NMR)and Fourier transform infrared spectroscopy(FTIR).The microstructures of the hydrogels were observed by scanning electron microscope(SEM),and the mechanical properties of the hydrogels were tested by a rotational rheometer and a dynamic mechanical analyzer(DMA).The induced hypoxic behaviors of the hydrogels were detected by an oxygen consumption fluorescent probe.The biocompatibility of the hydrogels was tested by live/dead staining and the cell counting kit 8(CCK-8)assay,and the expression of hypoxia-inducible factor-1α(HIF-1α)and type Ⅱ collagen(Col Ⅱ)in NPCs was detected by immunofluorescence staining.A rat model of intervertebral disc degeneration was established,and hydrogels loaded with NPCs were injected into degenerated intervertebral discs to evaluate their repair effects.Disc height and disc water content changes were detected by X-ray imaging and magnetic resonance imaging(MRI),and the integrity of disc structure and proteoglycan levels were detected by histological staining.Results·Structural characterization demonstrated that the materials had been successfully prepared.SEM showed that the three hydrogels all had a loose and porous structure,and their elastic moduli increased with the decrease of pore size.Hypoxia test results indicated that the hypoxia-inducing ability of HMGL-10 hydrogel was the strongest.In vitro experimental results showed that the three hydrogels all had good biocompatibility.Compared with the HAMA hydrogel,the HIF-1α of NPCs was significantly activated in the HMGL-10 hydrogel.The expression levels of HIF-1α and Col Ⅱ in the HMGL-10 hydrogel group were 3.38 and 4.15 times higher than those in the HAMA hydrogel group.In vivo experimental results showed that the integrity,height,and water content of the intervertebral discs in the hypoxia hydrogel group were all superior to those in the other treatment groups.Conclusion·The in situ hypoxia-inducing hydrogel effectively activates HIF-1α,promotes extracellular matrix secretion,and demonstrates superior regenerative potential for intervertebral disc repair.