Objective To optimize the platelet enrichment method,and to analyze the concentration changes of key molecules in platelet-rich plasma(PRP)before and after activation,as well as the impact of its activated products on the proliferation of rat endothelial progenitor cells.Methods The tube double-centrifu-gation method was employed to optimize platelet enrichment,and the platelet count in the enriched PRP was measured.ELISA was used to detect the concentration changes of vascular endothelial growth factor(VEGF),endostatin(ES),and P-selectin(CD62P)in PRP before and after activation.The PRP was activated by using liquid nitrogen freeze-thaw method,and the effect of its activated products on the proliferation of rat endothelial progenitor cells was evaluated by using the methyl thiazolyl tetrazolium(MTT)assay.Results The optimal enrichment coefficient of platelets achieved by the double-centrifugation method was 4.63.After low-speed,long-duration double centrifugation,the platelet count was highest in the upper layer of the buffy coat.For PRP with a platelet count of 500× 109/L obtained by machine collection,the VEGF con-centrations before and after activation were(3 418.12±488.80)pg/mL and(4 530.04±308.30)pg/mL,re-spectively,the ES concentrations were(6 168.98±253.22)pg/mL and(6 594.65±82.47)pg/mL,respec-tively,the CD62P concentrations were(6 678.23±324.15)pg/mL and(17 630.53±746.24)pg/mL,respec-tively,statistically significant differences were observed in the above indicators before and after activation(P＜0.01).The activated PRP was diluted in a gradient manner by using a specialized culture medium for en-dothelial progenitor cells.MTT assay results indicated that,in the basal medium,the optimal volume fraction for promoting endothelial progenitor cell proliferation was 0.25％after 48 hours of culture;in the complete medium,the optimal volume fractions for promoting endothelial progenitor cell proliferation were 0.062 5％after 24 hours and 0.125％after 48 hours.Conclusion The concentrations of VEGF,ES,and CD62P in the optimized,enriched PRP exhibited significant changes before and after activation.The optimal volume fraction for promoting endothelial progenitor cell proliferation in the basal medium was 0.25％.

Apical microsurgery is accurate and minimally invasive, produces few complications, and has a success rate of more than 90%. However, due to the lack of awareness and understanding of apical microsurgery by dental general practitioners and even endodontists, many clinical problems remain to be overcome. The consensus has gathered well-known domestic experts to hold a series of special discussions and reached the consensus. This document specifies the indications, contraindications, preoperative preparations, operational procedures, complication prevention measures, and efficacy evaluation of apical microsurgery and is applicable to dentists who perform apical microsurgery after systematic training.
Microsurgery/standards* ; Humans ; Apicoectomy ; Contraindications, Procedure ; Tooth Apex/diagnostic imaging* ; Postoperative Complications/prevention & control* ; Consensus ; Treatment Outcome

OBJECTIVE To establish a preparation system for megakaryocytes(MKs)derived from human embryonic stem cells(hESCs)and MK microparticles(MKMPs),and to assess the pro-angio-genic efficiency of these microparticles.METHODS ①hESCs were induced to mesodermal progenitor cells via monolayer culture with the first-stage induction medium for 2 days before the cells were induced to hemogenic endothelial/hematopoietic progenitor cells by culturing with the second-stage induction medium for another 3 days.Then,the cells were dissociated into single cells,seeded into the third-stage induction medium,and cultured using the suspension method for 8 days to obtain MKs.The specific characters of differentiated cells were identified through morphological observation and flow cytometry before stage-specific marker proteins in different periods were analyzed[hESCs:TRA-1-60,sialyl glycolipid stage-specific embryonic antigen4(SSEA4)];mesodermal progenitor cells:brachyury;hemogenic endothelial/hematopoietic progenitor cells:CD34,CD43;MKs:CD41a,CD42b),and immu-nofluorescence staining[β1-tubulin,von Willebrand factor(VWF)],[friend leukemia integration 1(FLI1),CD42].② MKMP collection and verification:MKMPs were collected via differential centrifugation.The concentration and size of these MKMPs were determined by nanoparticle tracking analysis(NTA),and both the morphology and ultrastructure were examined by transmission electron microscopy(TEM).Besides,the MKMPs-specific proteins[CD41,tumor susceptibility gene 101(TSG101)and CD9]were detected by Western blotting analysis.③ Biological function of MKMPs:MKMPs were stained with CD41a-PE antibodies and co-cultured with human umbilical veinvascular endothelial cells(HUVECs)labeled by CD34-APC for 3 h.Live-cell immunofluorescence was employed to find out whether HUVECs could absorb MKMPs.To find out whether MKMPs could affect the role of HUVECs in angio-genesis and cell migration,platelet microvesicles(PMPs)were used as positive controls.The experi-mental groups were added with different concentrations of microparticles(1,5,10 and 20 mg·L-1)while the control group was given no microparticles(0 mg·L-1).The number of nodes that formed the lumen after 5 h of incubation in Matrigel was counted,and the size of healing of the scratch area was analyzed after 6 h.To elucidate the mechanism through which MKMPs impacted angiogenesis,ELISA was used out to quantitatively detect the concentration of proteins in microparticles.RESULTS ① A three-stage differentiation cultural system was established to develop hESCs into MKs.Flow cytometry revealed progressive loss of pluripotency markers SSEA4 and TRA-1-60,while the mesodermal progenitor marker brachyury peaked at d 2.Subsequently,hemogenic endothelial/hematopoietic progenitor markers CD34 and CD43 emerged at d 5,followed by megakaryocytic markers CD41a and CD42b at d 13.Immunofluorescent images further demonstrated that MKs expressed specific proteins CD42,β1-tubulin,von VWF and FLI1 at d 13.②Microparticles were collected via differential centrifuga-tion.Transmission electron microscopy revealed that their substructure exhibited a typical double-layered membrane.Nanoparticle tracking analysis indicated that the size was(164.3±14.0)nm.The result of WB demonstrated that the microparticles expressed specific markers,including TSG101,CD9 and CD41.③ MKMPs were absorbed after being co-cultured with HUVECs for 3 h and enhanced the ability of HUVECs to form tubes and migrate.Notably,the treatment of 5 mg·L-1 MKMPs was more effective than 5 mg·L-1 PMPs treatment.The results of ELISA showed that the content of VEGF from MKMPs was higher than from PMPs,which may be the key factor in regulating endothelial biological function.CONCLUSION MKs derived from hESCs can generate functional microparticles which can promote angiogenesis.

The classical latent structure method does not consider the influence of primary and secondary symptoms,syndromes and symptoms in the analysis and modeling of syndromes.In this paper,based on the data of damp-heat in intestine and stomach syndrome involving 1087 diabetic patients,the classical latent structure analysis was used to obtain the quantitative syndrome diagnostic rules.Then,using Constrained Latent Tree Analysis(CLTA),the quantitative syndrome diagnostic rules containing primary and secondary symptoms were obtained as follows,primary symptoms include halitosis(2.3),yellow tongue coating(2),abdominal distension(2.3),greasy tongue coating(2.1),loose stool or loose stool(1.5),red tongue(1.3),smooth pulse(1.4).Secondary symptoms include epigastric distension(1.1).Compared with the traditional latent structure analysis method,the rules established by CLTA are more compatible with the concept of differentiating primary and secondary symptoms and the common practice of TCM.The quantitative syndrome diagnostic rules of damp-heat in intestine and stomach syndrome constructed by the CLTA method have considerable objectivity in the modeling process.The diagnostic rules established were also compatible with the qualitative concept of TCM theory in stratifying primary and secondary symptoms.Finally,the diagnostic rules are obtained by logistic regression analysis,and the accuracy of the three rules is compared.The results show that the rule recognition accuracy obtained by CLTA is the highest.Therefore,the syndrome diagnostic rules of damp-heat in intestine and stomach obtained from the analysis of CLTA are in line with the constraint semantics of primary and secondary diseases and the theory of traditional Chinese medicine.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Nine novel compounds, comprising seven tetrahydroanthraquinones (auxarthrolones A-G, 1-7), a γ-butenolide glycoside (malfilamentoside E, 26), and a γ-butenolide (auxarthrolide A, 27), together with eighteen known compounds (8-25) were isolated from rice-based solid culture of Auxarthron umbrinum (A. umbrinum) DSM3193 using the one strain many compounds (OSMAC) approach. The structural elucidation of these compounds was accomplished through nuclear magnetic resonance (NMR), mass spectrometry (MS), and NMR calculation combined with DP4+ analysis or MAEΔΔδ parameter, while the absolute configurations of new compounds were established through single-crystal X-ray diffraction, electronic circular dichroism (ECD) spectroscopic data analysis and/or chemical derivatization. Austrocortilutein (10) and auxarthrol H (14) demonstrated moderate cytotoxicity against U87 and U251 [half maximal inhibitory concentration (IC₅₀) 3.5-12.1 μmol·L^-1]. Additionally, auxarthrolone A (1), auxarthrol H (14), eupolyphagin B (15), and 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (17) exhibited torsional effects on fibroblast proliferation challenges induced by oleic acid, thus demonstrating fibroblast proliferation-promoting activity.
4-Butyrolactone/pharmacology* ; Molecular Structure ; Anthraquinones/pharmacology* ; Humans ; Animals ; Mice ; Cell Line, Tumor ; Magnetic Resonance Spectroscopy

Small nuclear RNAs (snRNAs) refer to a class of highly abundant and functionally important non-coding small RNAs that are localized in the eukaryotic nucleus. These snRNAs are highly conserved in different eukaryotes during evolution and form complexes with specific chaperones to fulfill critical biological functions, including precursor messenger RNA (pre-mRNA) splicing and ribosomal RNA (rRNA) modification. Consequently, the regulation of snRNA gene expression is a crucial biological process for plants. In plants, the transcription and processing of snRNAs are regulated by RNA polymerase (Pol), snRNA-activating protein complex (SNAPc), defective in snRNA processing (DSP), and specific cis-elements in the snRNA promoter regions. Proper regulation of snRNA expression is essential for normal plant growth, development, and stress responses. This review summarizes the classification, structures, transcriptional regulation, and biological functions of plant snRNA genes, while outlining future research directions for snRNAs.
RNA, Small Nuclear/physiology* ; Gene Expression Regulation, Plant ; Transcription, Genetic ; Plants/metabolism* ; RNA, Plant/genetics*