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.

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.

Objective To investigate the effects of long noncoding RNA(lncRNA)-NRON on apoptosis following myocardial infarc-tion(MI)in mice.Methods The C57BL/6 mice were randomly divided into four groups:sham operation(Sham)group,MI group,MI combined with lncRNA-NRON interference lentivirus(MI+shNRON)group,and MI combined with the negative control(NC)lentivirus(MI+NC)group.The expression of lncRNA-NRON was detected using real-time PCR.In addition,the pathology of the myocardial tissue injury was analyzed using HE staining,the myocardial infarction size was examined using TTC staining,and the extent of apoptosis was assessed using the TUNEL assay,respectively.The RPISeq database was used to predict the probability of interaction between lncR-NA-NRON and the voltage-dependent anionic channel protein(VDAC).The effect of lncRNA-NRON on the expression of VDAC protein was detected using Western blotting.Results The lncRNA-NRON expression was significantly increased in the MI group,and the tar-geted knockdown of lncRNA-NRON resulted in alleviation of the pathological myocardial tissue injury,reduction in the myocardial infarc-tion area,and inhibition of apoptosis.The probability of interaction between lncRNA-NRON and VDAC reached 0.9,indicating a high probability of their association.Additionally,lncRNA-NRON could regulate the protein expression of VDAC.Conclusion Knockdown of lncRNA-NRON could reduce the occurrence of myocardial injury following myocardial infarction.This effect may be attributable to a spe-cific mechanism wherein lncRNA-NRON affects the process of apoptosis by binding to VDAC,consequently suppressing its expression.

Objective To analyze and identify the volatile constituents in different parts(flowers,stems and leaves)of Huai chrysanthemumin,and to lay a theoretical foundation for the comprehensive utilization for it.Methods The volatile oil in different parts of Huai chrysanthemumin were extracted by hydrodistillation,respectively.Their constituents were analyzed by gas chromatography-mass spectrometry(GC-MS).The compounds were identified by library search and literature screening.The relative percentage of each compound was obtained by the area normalization method.The differences in their chemical compositions were analyzed by Venn diagram,principal component analysis(PCA)and cluster heat map analysis.Results A total of 62 volatile chemical components were identified from different parts of Huai chrysanthemumin,including monoterpenes,sesquiterpenes,and their derivatives,as well as a small amount of aliphatic compounds.32,42 and 40 volatile components were detected from the flowers,stems and flowers,respectively.Furthermore 17 volatile components were shared by three parts,whereas 5,6 and 16 volatile components were unique to the flowers,stems and leaves,respectively.The results of stoichiometric analysis showed that both PCA and cluster heat map analysis could separate the flowers,stems and leaves,and their volatile components were different.Conclusion The types and contents of the volatile oil in the stems,leaves and flowers of Huai chrysanthemumin have certain variability,which provide a scientific basis for the further medicinal or industrial exploitation of different parts of Huai chrysanthemumin.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive 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:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objectives:To establish a risk prediction model for gastrointestinal bleeding after cardiopulmonary bypass heart surgery,and to verify the prediction efficacy. Methods:A total of 1 002 patients who underwent cardiopulmonary bypass heart surgery in the department of cardiac great vascular surgery of our hospital from January 2019 to November 2023 were collected by convenient sampling method.They were divided into gastrointestinal bleeding group(n=47)and non-gastrointestinal bleeding group(n=955).Logistic regression analysis was used to establish the risk prediction model,and the area under ROC curve test and Hosmer-Lemeshow χ2 test were used to compare the two groups of data Model prediction effect.Bootstrap method was used for internal validation. Results:The risk prediction model of gastrointestinal bleeding after cardiopulmonary bypass heart surgery included four predictors:time of aortic occlusion(OR=1.021,95%CI:1.012-1.030),history of digestive disease(OR=5.710,95%CI:1.697-19.212),use of intra-aortic balloon counterpulsation(OR=22.180,95%CI:5.870-83.808),and continuous kidney replacement therapy(OR=12.159,95%CI:5.066-29.181).Model formula:Logit(P)=-5.821+0.021×time of aortic occlusion+1.742×history of digestive disease+3.099×whether intra-aortic balloon counterpulsation was used+2.498×whether continuous renal replacement therapy was used.The area under ROC curve was 0.812(95%CI:0.746-0.877),sensitivity was 64.6%,specificity was 85.7%,and Youden index was 0.503.After internal validation by Bootstrap method,the consistency index after correction is 0.813. Conclusions:The risk prediction model constructed in this study cohort has a good auxiliary prediction performance for the occurrence of gastrointestinal bleeding after cardiopulmonary bypass surgery,which is helpful for risk stratification for gastrointestinal bleeding after cardiopulmonary bypass surgery and facilitate clinical decision-making in daily clinical work.

Objective To compare the efficacy of ultrasound-guided microwave ablation versus thyroidectomy in the treatment of benign thyroid nodules (BTN) and to explore the influencing factors of prognosis. Methods A total of 282 BTN patients were enrolled and divided into ablation group (treated with ultrasound-guided microwave ablation, n=172) and resection group (treated with thyroidectomy, n=110) based on treatment methods. Perioperative indicators and thyroid function indices before and after surgery were compared between the two groups. Patients were followed up for 1 year and divided into good prognosis group [volume reduction rate (VRR)≥80%, n=210] and a poor prognosis group (VRR < 80%, n=72) based on the VRR. Factors influencing the prognosis of BTN patients were analyzed. Results The ablation group had shorter operative time and hospital stay, less intraoperative blood loss, and lower postoperative Visual Analogue Scale (VAS) scores compared to the resection group (P < 0.05). One month after surgery, serum thyrotropin (TSH) levels were higher, while free triiodothyronine (FT3) and free thyroxine (FT4) levels were lower than preoperative levels in both groups, however, TSH level was lower, and FT3 and FT4 levels were higher in the ablation group compared to the resection group (P < 0.05). Univariate analysis showed that preoperative TSH levels, the proportion of solid nodules, and the proportion of nodules in the risk zone were lower, while preoperative FT4 levels were higher in the good prognosis group compared to the poor prognosis group (P < 0.05). Binary Logistic regression analysis revealed that nodule type, nodule location, preoperative TSH, and preoperative FT4 were all influencing factors for the prognosis of BTN patients (P < 0.05). Conclusion Compared to thyroidectomy, ultrasound-guided microwave ablation for BTN offers advantages such as less intraoperative blood loss, milder postoperative pain, shorter operative time and hospital stay, and less damage to thyroid function. Preoperative TSH and FT4 levels, nodule type, and nodule location are closely related to the prognosis of BTN patients and should be given attention in clinical practice.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective:To evaluate the correlation between elevated cTnI level and 28-day mortality after liver transplantation.Methods:A retrospective study was conducted in adult patients admitted to ICU after liver transplantation from Jun 2015 to March 2019 at Beijing Chao-Yang Hospital. The cardiac troponin Ⅰ levels within 48 h after surgery were examined. Patients outcome was followed up,the primary end point was mortality within 28-day. Univariate and multivariate logistic regression models were used to look for predictors of 28-day mortality.Results:Three hundred and eighteen patients were included in our analyses. Twenty-six patients died and 292 survived within 28 days after LT. Two hundred and forty-three of 318 (76.4%) cases presented elevated cTnI in the early stage after LT. Thirty-seven of 318 (11.6%) patients presented a moderate elevation of cTnI level (5-10 times over normal upper limit), 75 (23.6%) of them presented severe cTnI elevation (10 times over normal upper limit). Univariate and multivariate logistic regression model shows severe cTnI elevation was the independent prognostic factors associated with 28-day mortality [Odds Ratio (95% confidence interval)=3.151(1.218-8.150), P=0.018]. Conclusion:Early cTnI elevation is common after liver transplantation, and severe cTnI elevation is significantly associated with 28-day mortality.

Objective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2018 to December 2019. Antibiotic susceptibility tests were conducted with agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 14 778 bacterial strains were collected from 50 hospitals, of which 4 117 (27.9%) were Gram-positive bacteria and 10 661(72.1%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.2%), Klebsiella pneumoniae (17.0%), Staphylococcus aureus (9.7%), coagulase-negative Staphylococci (8.7%), Pseudomonas aeruginosa (3.7%), Enterococcus faecium (3.4%), Acinetobacter baumannii(3.4%), Enterobacter cloacae (2.9%), Streptococci(2.8%) and Enterococcus faecalis (2.3%). The the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus were 27.4% (394/1 438) and 70.4% (905/1 285), respectively. No glycopeptide-resistant Staphylococcus was detected. More than 95% of S. aureus were sensitive to amikacin, rifampicin and SMZco. The resistance rate of E. faecium to vancomycin was 0.4% (2/504), and no vancomycin-resistant E. faecalis was detected. The ESBLs-producing rates in no carbapenem-resistance E. coli, carbapenem sensitive K. pneumoniae and Proteus were 50.4% (2 731/5 415), 24.6% (493/2001) and 35.2% (31/88), respectively. The prevalence of carbapenem-resistance in E. coli and K. pneumoniae were 1.5% (85/5 500), 20.6% (518/2 519), respectively. 8.3% (27/325) of carbapenem-resistance K. pneumoniae was resistant to ceftazidime/avibactam combination. The resistance rates of A. baumannii to polymyxin and tigecycline were 2.8% (14/501) and 3.4% (17/501) respectively, and that of P. aeruginosa to carbapenem were 18.9% (103/546). Conclusions:The surveillance results from 2018 to 2019 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while E. coli was the most common pathogen, and ESBLs-producing strains were in majority; the MRSA incidence is getting lower in China; carbapenem-resistant E. coli keeps at a low level, while carbapenem-resistant K. pneumoniae is on the rise obviously.