ObjectiveTo investigate the mechanisms of mitochondrial dynamics and metabolic reprogramming in the treatment of diabetic nephropathy （DN） by Shenxiao Tongluo prescription via the peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α）/sirtuin-3 （SIRT3）/hypoxia-inducible factor-1α （HIF-1α） signaling pathway. MethodsSixty-five SD rats were randomized into a sham group （10 rats） and a modeling group （55 rats）， and the modeling rats underwent left nephrectomy and intraperitoneal injection of streptozotocin （35 mg·kg^-1） to prepare a DN model. After successful modeling， the rats were randomized into model， empagliflozin （10 mg·kg^-1）， and low-， medium-， and high-dose （7.656， 15.312， 30.624 g·kg^-1， respectively） Shenxiao Tongluo prescription groups. The urine microalbumin （UmAlb）， blood urea nitrogen （BUN）， and serum creatinine （SCr） levels of rats in each group were assessed after continuous gavage for 8 weeks. The corresponding kits were used to measure the levels of lactate， superoxide dismutase （SOD）， and malondialdehyde （MDA） in the kidney tissue. Hematoxylin-eosin staining， Masson staining， and periodic acid-Schiff staining were performed to observe the pathological changes in the kidney tissue. Transmission electron microscopy was employed to observe mitochondrial morphology. Immunohistochemistry was employed to determine the expression levels of dynamin-related protein 1 （DRP1） and pyruvate kinase M2 （PKM2） in the kidney tissue. Western blot was adopted to assess the protein levels of PGC-1α， SIRT3， HIF-1α， dynamin-related protein 1 （Drp1）， optic atrophy 1 （OPA1）， hexokinase 2 （HK2）， and pyruvate kinase M2 （PKM2） in the kidney tissue. ResultsCompared with the sham group， the model group showed elevated levels of UmAlb， BUN， SCr， lactate， and MDA， decreased SOD level （P<0.05）， glomerular hypertrophy， thickening of the mesangial basement membrane， vacuolar degeneration of renal tubular epithelial cells， and infiltration of renal interstitial inflammatory cells， oval mitochondria with disordered， blurred or disappearing cristae， down-regulated protein levels of PGC-1α， SIRT3， and OPA1， and up-regulated protein levels of HIF-1α， DRP1， HK2， and PKM2 （P<0.05）. Compared with the model group， the treatment in all the groups increased the body weight， lowered the levels of GLU， UmAlb， BUN， and MDA， raised the level of SOD， alleviated the pathological damage in the kidney tissue and mitochondrial damage， up-regulated the expression of PGC-1α， SIRT3， and OPA1， and down-regulated the expression of HIF-1α， DRP1， and PKM2 （P<0.05）. Empagliflozin and Shenxiao Tongluo prescription at medium and high doses lowered the levels of SCr and lactate and down-regulated the expression of HK2 （P<0.05）， which had no statistical significance in the low-dose Shenxiao Tongluo prescription group. ConclusionShenxiao Tongluo prescription may regulate mitochondrial dynamics and metabolic reprogramming by activating the PGC-1α/SIRT3/HIF-1α pathway， thereby alleviating oxidative damage in the kidney tissue and delaying the progression of DN.

ObjectiveTo investigate the mechanisms of mitochondrial dynamics and metabolic reprogramming in the treatment of diabetic nephropathy （DN） by Shenxiao Tongluo prescription via the peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α）/sirtuin-3 （SIRT3）/hypoxia-inducible factor-1α （HIF-1α） signaling pathway. MethodsSixty-five SD rats were randomized into a sham group （10 rats） and a modeling group （55 rats）， and the modeling rats underwent left nephrectomy and intraperitoneal injection of streptozotocin （35 mg·kg^-1） to prepare a DN model. After successful modeling， the rats were randomized into model， empagliflozin （10 mg·kg^-1）， and low-， medium-， and high-dose （7.656， 15.312， 30.624 g·kg^-1， respectively） Shenxiao Tongluo prescription groups. The urine microalbumin （UmAlb）， blood urea nitrogen （BUN）， and serum creatinine （SCr） levels of rats in each group were assessed after continuous gavage for 8 weeks. The corresponding kits were used to measure the levels of lactate， superoxide dismutase （SOD）， and malondialdehyde （MDA） in the kidney tissue. Hematoxylin-eosin staining， Masson staining， and periodic acid-Schiff staining were performed to observe the pathological changes in the kidney tissue. Transmission electron microscopy was employed to observe mitochondrial morphology. Immunohistochemistry was employed to determine the expression levels of dynamin-related protein 1 （DRP1） and pyruvate kinase M2 （PKM2） in the kidney tissue. Western blot was adopted to assess the protein levels of PGC-1α， SIRT3， HIF-1α， dynamin-related protein 1 （Drp1）， optic atrophy 1 （OPA1）， hexokinase 2 （HK2）， and pyruvate kinase M2 （PKM2） in the kidney tissue. ResultsCompared with the sham group， the model group showed elevated levels of UmAlb， BUN， SCr， lactate， and MDA， decreased SOD level （P<0.05）， glomerular hypertrophy， thickening of the mesangial basement membrane， vacuolar degeneration of renal tubular epithelial cells， and infiltration of renal interstitial inflammatory cells， oval mitochondria with disordered， blurred or disappearing cristae， down-regulated protein levels of PGC-1α， SIRT3， and OPA1， and up-regulated protein levels of HIF-1α， DRP1， HK2， and PKM2 （P<0.05）. Compared with the model group， the treatment in all the groups increased the body weight， lowered the levels of GLU， UmAlb， BUN， and MDA， raised the level of SOD， alleviated the pathological damage in the kidney tissue and mitochondrial damage， up-regulated the expression of PGC-1α， SIRT3， and OPA1， and down-regulated the expression of HIF-1α， DRP1， and PKM2 （P<0.05）. Empagliflozin and Shenxiao Tongluo prescription at medium and high doses lowered the levels of SCr and lactate and down-regulated the expression of HK2 （P<0.05）， which had no statistical significance in the low-dose Shenxiao Tongluo prescription group. ConclusionShenxiao Tongluo prescription may regulate mitochondrial dynamics and metabolic reprogramming by activating the PGC-1α/SIRT3/HIF-1α pathway， thereby alleviating oxidative damage in the kidney tissue and delaying the progression of DN.

In recent years, the application of artificial intelligence (AI) in the field of biology has witnessed remarkable advancements. Among these, the most notable achievements have emerged in the domain of protein structure prediction and design, with AlphaFold and related innovations earning the 2024 Nobel Prize in Chemistry. These breakthroughs have transformed our ability to understand protein folding and molecular interactions, marking a pivotal milestone in computational biology. Looking ahead, it is foreseeable that the accurate prediction of various physicochemical properties of proteins—beyond static structure—will become the next critical frontier in this rapidly evolving field. One of the most important protein properties is thermodynamic stability, which refers to a protein’s ability to maintain its native conformation under physiological or stress conditions. Accurate prediction of protein stability, especially upon single-point mutations, plays a vital role in numerous scientific and industrial domains. These include understanding the molecular basis of disease, rational drug design, development of therapeutic proteins, design of more robust industrial enzymes, and engineering of biosensors. Consequently, the ability to reliably forecast the stability changes caused by mutations has broad and transformative implications across biomedical and biotechnological applications. Historically, protein stability was assessed via experimental methods such as differential scanning calorimetry (DSC) and circular dichroism (CD), which, while precise, are time-consuming and resource-intensive. This prompted the development of computational approaches, including empirical energy functions and physics-based simulations. However, these traditional models often fall short in capturing the complex, high-dimensional nature of protein conformational landscapes and mutational effects. Recent advances in machine learning (ML) have significantly improved predictive performance in this area. Early ML models used handcrafted features derived from sequence and structure, whereas modern deep learning models leverage massive datasets and learn representations directly from data. Deep neural networks (DNNs), graph neural networks (GNNs), and attention-based architectures such as transformers have shown particular promise. GNNs, in particular, excel at modeling spatial and topological relationships in molecular structures, making them well-suited for protein modeling tasks. Furthermore, attention mechanisms enable models to dynamically weigh the contribution of specific residues or regions, capturing long-range interactions and allosteric effects. Nevertheless, several key challenges remain. These include the imbalance and scarcity of high-quality experimental datasets, particularly for rare or functionally significant mutations, which can lead to biased or overfitted models. Additionally, the inherently dynamic nature of proteins—their conformational flexibility and context-dependent behavior—is difficult to encode in static structural representations. Current models often rely on a single structure or average conformation, which may overlook important aspects of stability modulation. Efforts are ongoing to incorporate multi-conformational ensembles, molecular dynamics simulations, and physics-informed learning frameworks into predictive models. This paper presents a comprehensive review of the evolution of protein thermodynamic stability prediction techniques, with emphasis on the recent progress enabled by machine learning. It highlights representative datasets, modeling strategies, evaluation benchmarks, and the integration of structural and biochemical features. The aim is to provide researchers with a structured and up-to-date reference, guiding the development of more robust, generalizable, and interpretable models for predicting protein stability changes upon mutation. As the field moves forward, the synergy between data-driven AI methods and domain-specific biological knowledge will be key to unlocking deeper understanding and broader applications of protein engineering.

BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.

⁶³Ni is predominantly generated through neutron activation in nuclear reactors and is classified as a pure beta-emitting radionuclide with a half-life of 101.1 a. During decay, ⁶³Ni emits a beta ray with an energy of 65.87 keV. ⁶³Ni can be used in the manufacture of beta radiation sources, which are utilized as reference and working sources for beta activity measurement and beta energy response calibration. Additionally, it is used in electron capture detectors for chromatography, ionization sources in electron tubes, and electron capture probes in gas chromatography. These instruments have extensive applications in food safety, public health and epidemic prevention, soil pollution monitoring, and security. ⁶³Ni is an artificial radionuclide not commonly found in the natural environment under normal conditions. However, the ⁶³Ni generated during routine operations of nuclear power plants, as well as residual materials and wastes contaminated with ⁶³Ni during plant decommissioning, may be released into the environment through liquid effluents or solid wastes. This can pose potential radiation risks to both the public and the environment. Hence, it is necessary to monitor the activity concentration of ⁶³Ni. Currently, reports on this subject are limited in China, and there is a lack of established standards for the determination of ⁶³Ni in nuclear power plants. This article reviews the global literature on the pretreatment and purification measurement processes of ⁶³Ni. The merits and demerits are summarized for pretreatment methods such as acid leaching, mixed acid digestion, ashing acid leaching/dissolution, and alkali fusion, and for separation and purification methods like solvent extraction, precipitation, and extraction chromatography. The article also highlights the advantages of measurement using liquid scintillation counters. This review provides a reference for the establishment of the determination method of ⁶³Ni in liquid effluents and solid wastes from nuclear power plants.

Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease. Here, we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum- and PDGF-BB-induced vascular smooth muscle cells (VSMCs), and in tissues of carotid artery injury-induced neointimal hyperplasia. Smyd2 overexpression in VSMCs (Smyd2-vTg) facilitates, but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice. Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor (SRF) target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation. HDAC3 directly interacts with and deacetylates SRF, which enhances SRF transcriptional activity in VSMCs. Moreover, SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter. RGFP966, a specific inhibitor of HDAC3, not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs, but also inhibits carotid artery injury-induced neointima formation in mice. HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner. Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.

Objective To investigate the infection status and changing trend of hepatitis C virus(HCV)infection in hospitalized patients in medical institutions,and provide reference for formulating HCV infection prevention and control strategies.Methods HCV infection surveillance results from cross-sectional survey data reported to China Healthcare-associated Infection(HAI)Surveillance System in 2020 were summarized and analyzed,HCV positive was serum anti-HCV positive or HCV RNA positive,survey result was compared with the survey results from 2003.Results In 2020,1 071 368 inpatients in 1 573 hospitals were surveyed,738 535 of whom underwent HCV test,4 014 patients were infected with HCV,with a detection rate of 68.93％and a HCV positive rate of 0.54％.The positive rate of HCV in male and female patients were 0.60％and 0.48％,respectively,with a statistically sig-nificant difference(x2=47.18,P＜0.001).The HCV positive rate in the 50-＜60 age group was the highest(0.76％),followed by the 40-＜50 age group(0.71％).Difference among all age groups was statistically signifi-cant(x2=696.74,P＜0.001).In 2003,91 113 inpatients were surveyed.35 145 of whom underwent HCV test,resulting in a detection rate of 38.57％;775 patients were infected with HCV,with a positive rate of 2.21％.In 2020,HCV positive rates in hospitals of different scales were 0.46％-0.63％,with the highest in hospital with bed numbers ranging 600-899.Patients'HCV positive rates in hospitals of different scales was statistically signifi-cant(X2=35.34,P＜0.001).In 2020,12 provinces/municipalities had over 10 000 patients underwent HCV-rela-ted test,and HCV positive rates ranged 0.19％-0.81％,with the highest rate from Hainan Province.HCV posi-tive rates in different departments were 0.06％-0.82％,with the lowest positive rate in the department of pedia-trics and the highest in the department of internal medicine.In 2003 and 2020,HCV positive rates in the depart-ment of infectious diseases were the highest,being 7.95％and 3.48％,respectively.Followed by departments of orthopedics(7.72％),gastroenterology(3.77％),nephrology(3.57％)and general intensive care unit(ICU,3.10％)in 2003,as well as departments of gastroenterology(1.35％),nephrology(1.18％),endocrinology(0.91％),and general intensive care unit(ICU,0.79％)in 2020.Conclusion Compared with 2003,HCV positive rate decreased significantly in 2020.HCV infected patients were mainly from the department of infectious diseases,followed by departments of gastroenterology,nephrology and general ICU.HCV infection positive rate varies with gender,age,and region.

Objective To explore the association of the magnitude of systolic blood pressure reduction(SBPr)with post-procedure 24 h symptomatic intracranial hemorrhage(sICH)and 90-day clinical outcomes in patients with successful endovascular thrombectomy(EVT).Methods Consecutively registered patients with EVT caused by anterior circulation large vessel occlusion stroke(LVOS)in the First Affiliated Hospital of Wannan Medical College(Yijishan Hospital)between July 2015 and April 2023 and patients with successful reperfusion were analyzed.Demographic data,medical history(hypertension,diabetes),the trial of Org 10172 in acute stroke treatment(TOAST)classification,the baseline National Institutes of Health Stroke Scale(NIHSS)score and the baseline Alberta stroke early CT(ASPECT)score of patients were collected.And procedure related parameters(including time from onset to puncture,time from onset to reperfusion,occluded site[internal carotid artery,M1 segment of middle cerebral artery,M2 segment of middle cerebral artery],collateral circulation status[determined based on preoperative occluded angiography showing the range of collateral circulation in the occluded vessel area,defined as good collateral circulation with a reflux range of ≥ 50％and poor collateral circulation with a reflux range of＜50％]),immediate postoperative reperfusion status(evaluated using the modified thrombolysis for cerebral infarction[mTICI]grading,successful reperfusion defined as mTICI grading of 2b-3),24 hours sICH,and 90 days clinical outcomes(evaluated using the modified Rankin scale score at 90days after EVT,with a score ≤ 2indicating a good prognosis and a score＞2indicating a poor prognosis).SBPr was defined as(baseline SBP-mean SBP)/baseline SBP x 100％.According to the the magnitude of SBPr,SBPr is divided into 5 categories(＜-10％,-10％-10％,＞10％-20％,＞20％-30％and＞30％).Based on the clinical outcomes at 90 days and the occurrence of sICH at 24 hours after EVT,patients were divided into a good prognosis group and a poor prognosis group,as well as an sICH group and a non-sICH group.The relationship between SBPr and postoperative 90 days clinical prognosis or sICH was analyzed using a binary Logistic regression model.Subgroup analysis was conducted based on a history of hypertension(yes and no),continuous intravenous hypotensive therapy(yes and no),baseline ASPECT scores(3-5 and 6-10),and collateral circulation status(good and bad).Using a restricted cubic plot to depict the relationship between SBPr and sICH and clinical prognosis at 90days.Results(1)In total,731 patients were included.The median age was 71(62,77)years and 424(58.0％)were men.The median baseline NIHSS score was 14(12,18),the median baseline ASPECT was 9(7,10),405(55.4％)patients achieved 90-day modified Rankin scale score 0-2,and 35 patients(4.8％)developed sICH.(2)Multivariate analysis showed that the older age(OR,1.036,95％CI 1.017-1.056),the higher baseline NIHSS score(OR,1.095,95％CI1.049-1.144),the lower baseline ASPECT score(OR,0.704,95％CI 0.636-0.780),diabetes(OR,1.729,95％CI 1.084-2.758),bad collateral circulation(good collateral circulation vs.bad collateral circulation,OR,0.481,95％CI 0.332-0.696)and SBPr＞30％(SBPr-10％-10％as a reference,OR,2.238,95％CI 1.230-4.071),the higher the risk of poor clinical outcomes at 90 days(all P＜0.05).Continuous intravenous hypotensive therapy is a risk factor for postoperative 24 h sICH(OR,2.278,95％CI 1.047-4.953;P=0.038),while SBPr 20％-30％is associated with a lower risk of postoperative 24 h sICH(SBPr-10％-10％as a reference,OR,0.362,95％CI0.131-0.998;P=0.049).(3)The restrictive cube plot shows that there is a U-shaped relationship between SBPr after EVT and poor clinical outcomes at 90 days,while there is a nearly linear relationship with the occurrence of sICH.The more SBP reduction,the lower the incidence of sICH.(4)In the subgroup analyses,in the non-hypertension history and the good collateral circulation group,SBPr＞30％has a higher risk of poor clinical outcomes compared to SBPr-10％-10％(OR and 95％CI were 2.921[1.000-8.528]and 2.363[1.078-5.183],respectively,with P=0.05 or P＜0.05);After EVT,the group receiving continuous intravenous hypotensive therapy and the baseline ASPECT score 6-10 groups showed a significant correlation between SBPr＞30％and poor clinical outcomes at 90 days(SBPr-10％-10％as a reference,OR and 95％CI were 2.646[1.168-5.993]and 2.481[1.360-4.527],respectively,with P＜0.05).The correlation between SBPr and lower incidence of sICH was only found in the subgroup of poor collateral circulation(SBPr-10％-10％as a reference,SBPr＞20％-30％:OR,0.133,95％CI 0.027-0.652;SBPr＞30％:OR,0.104,95％CI 0.013-0.864;all P＜0.05).Conclusions Among patients who achieved successful reperfusion with EVT,SBPr might be related to a worse functional outcome at 90 days and sICH 24 h after operation.However,the relationship may exhibit significant heterogeneity across different subgroups.Baseline ASPECT score,history of hypertension,collateral circulation,and the use of continuous venous hypertension after EVT have been highlighted in individualized blood pressure management after EVT.

A GC-LSTM model is proposed based on the characteristics of global optimization of genetic algorithm.The model automatically and iteratively searches the optimal hyper-parameter configuration of the C-LSTM model through the genetic algorithm of a specific genetic strategy,and it is configured using the genetic iteration results and validated on the MIT-BIH arrhythmia database according to the classification criteria of the Association for the Advancement of Medical Instrumentation.The testing shows that the classification accuracy,sensitivity,accuracy and F1 value of GC-LSTM model are 99.37%,95.62%,95.17%and 95.39%,respectively,higher than those of the manually established model,and it is also advantageous over the existing mainstream methods.Experimental results demonstrate that the proposed method can achieve better classification performance while avoiding a large number of experimental parameters.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.