ObjectiveIn nature, objects cast shadows due to illumination, forming the basis for stereoscopic perception. Birds need to adapt to changes in lighting (meaning they can recognize stereoscopic shapes even when shadows look different) to accurately perceive different three-dimensional forms. However, how neurons in the key visual brain area in birds handle these lighting changes remains largely unreported. In this study, pigeons (Columba livia) were used as subjects to investigate how neurons in pigeon’s ventrolateral mesopallium (MVL) represent stereoscopic shapes consistently, regardless of changes in lighting. MethodsVisual cognitive training combined with neuronal recording was employed. Pigeons were first trained to discriminate different stereoscopic shapes (concave/convex). We then tested whether and how light luminance angle and surface appearance of the stereoscopic shapes affect their recognition accuracy, and further verify whether the results rely on specify luminance color. Simultaneously, neuronal firing activity of neurons was recorded with multiple electrode array implanted from the MVL during the presentation of difference shapes. The response was finally analyzed how selectively they responded to different stereoscopic shapes and whether their selectivity was affected by the changes of luminance condition (like lighting angle) or surface look. Support vector machine (SVM) models were trained on neuronal population responses recorded under one condition (light luminance angle of 45°) and used to decode responses under other conditions (light luminance angle of 135°, 225°, 315°) to verify the invariance of responses to different luminance conditions. ResultsBehavioral results from 6 pigeons consistently showed that the pigeons could reliably identify the core 3D shape (over 80% accuracy), and this ability wasn’t affected by changes in light angle or surface appearance. Statistical analysis of 88 recorded neurons from 6 pigeons revealed that 83% (73/88) showed strong selectivity for specific 3D shapes (selectivity index>0.3), and responses to convex shapes were consistently stronger than to concave shapes. These shape-selective responses remained stable across changes in light angle and surface appearance. Neural patterns were consistent under both blue and orange lighting. The decoding accuracy achieves above 70%, suggesting stable responses under different conditions (e.g., different lighting angles or surface appearance). ConclusionNeurons in the pigeon MVL maintain a consistent neural encoding pattern for different stereoscopic shapes, unaffected by illumination or surface appearance. This ensures stable object recognition by pigeons in changing visual environments. Our findings provide new physiological evidence for understanding how birds achieve stable perception (“invariant neural representations”) while coping with variations in the visual field.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

This study investigated the characteristics of gut microbiota imbalance in patients with infectious diarrhea caused by various pathogenic infections,and the role of Bacteroides in maintaining homeostasis in the intestinal environment.The gut microbiota in patients with diarrhea caused by pathogenic infections,such as viral and bacterial infections,was determined through full-length 16S rRNA amplicon sequencing.Patients with diarrhea were grouped and analyzed according to the presence of single bacterial infection,single viral infection,mixed infection,or Clostridioides difficile infection.Bacteroides had the highest absolute number and relative abundance in the gut microbiota in healthy people,whereas patients with infectious diar-rhea showed lower relative abundance of Bacteroides at each phylum/order/family/genus taxonomic level.Alpha diversity anal-ysis indicated no significant differences among groups.NMDS and PCoA indicated formation of distinct clusters in the control group compared with the different infectious diarrhea groups.The diversity of the gut microbiota was higher in the control group than the infectious diarrhea groups.Patients with infec-tious diarrhea caused by different pathogens showed differing predominant gut microbiota.Bifidobacterium predominated in the single viral infection group,Streptococcus predominated in the single bacterial infection group,and Lachnoclostridium predominated in the mixed infection group.Escherichia and Klebsiella were the major gut microbiota in the C.difficile infection group.Meanwhile,the dominant gut microbiota in the healthy population was Bacteroides.COG function prediction revealed that the healthy control group formed a distinct cluster from the different infection groups.The functions of defense mechanisms,cell wall synthesis,protein modification,cellular differentiation,and replication and recombination were signifi-cantly diminished in all infectious diarrhea groups.In general,patients with infectious diarrhea caused by different pathogens showed dysbiosis,with diminished gut microbiota diversity and the emergence of related biomarkers.Our findings indicated that Bacteroides has a key role in maintaining the homeostasis of the human intestinal environment,thus providing new ideas for the subsequent treatment of infectious diarrhea and research in other fields.

Objective:To investigate the expression level,clinical significance and function of circular RNAs(circRNAs)circ_0073585 in the bone marrow of patients with acute myeloid leukemia(AML).Methods:The expression levels of circ_0073585 in bone marrow samples of 106 newly diagnosed AML patients and 38 controls were detected by real-time quantitative PCR(RQ-PCR).The differences were compared between the two groups and their clinical significance was analyzed.The diagnostic value of circ_0073585 expression for AML was evaluated by receiver operating characteristic curve(ROC).THP-1 cells with lentivirus overexpressing circ_0073585 vector and empty vector were divided into two groups:circ_0073585-THP-1 and NC-THP-1 group.CCK-8 assay and flow cytometry were used to study the effects of circ_0073585 on THP-1 cell proliferation,survival,apoptosis and drug sensitivity.Results:Compared with the controls,the expression level of circ_0073585 in the bone marrow of AML patients was significantly reduced(P＜0.001).There was a statistically significant difference between the high and low expression groups of circ_0073585 in the white blood cell count,platelet count(P＜0.01)and chromosome risk(P＜0.05).Compared with NC-THP-1 cells,the proliferation and viability of circ_0073585-THP-l cells were weakened(P＜0.01),the apoptosis rate was increased(P＜0.01),and the sensitivity to homoharringtonine(P＜0.05)and daunorubicin hydrochloride(P＜0.001)was increased.Conclusion:The expression level of circ_0073585 is decreased in AML patients.Overexpression of circ_0073585 can inhibit the proliferation and viability of leukemic cells,promote apoptosis,and increase sensitivity of leukemia cells to chemotherapy drugs.

AIM To study the chemical constituents from the ethyl acetate fraction of Baccharis trimera(Less.)DC.METHODS The ethyl acetate fraction of B.trimera was isolated and purified by macroporous resin D101,Sephadex LH-20 gel,silica gel and other chromatographic techniques,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Twenty-three compounds were isolated and identified as 15,16-epoxy-15α-methoxy-ent-clerod-3-en-18-oic acid(1),13-epi-15,16-epoxy-15α-methoxy-ent-clerod-3-en-18-oic acid(2),methyltrineracetal(3),epimethyltrineracetal(4),trinerolide(5),15-epitrinerolide(6),18-methylmalonyl-7α-hydroxy-meth-yltrineracetal(7),18-methylmalonyl-7α-hydroxy-epimethyltriner-acetal(8),18-methylmalonyl-methyltrineracetal(9),18-methylmalonyl-epi-methyltrineracetal(10),methy 3,5-dicaffeoylquinate(11),8-dimetho-xyflavone(12),4',7-dihydroxy-5-methoxyflavanone(13),4-(3',4'-dihydroxycinna-moyl)-oxy-methy-lcinnamate(14),3',7-dihydroxy-4',6,8-trimethoxy-flavone(15),erigeroflavanone(16),nepetin(17),4,2',4',β-tetrahydroxy-6'-methoxy-α,β-dihydrochalcone(18),eugeniyl-O-β-D-glucoside(19),7-hydroxyl-5,6,3',4'-tetramethoxylflavone(20),phomoxanthone J(21),18-acetyl-7α-hydroxy-methyltrineracetal(22),18-acetyl-7α-hydroxy-epimethyltrineracetal(23).CONCLUSION Compounds 3-10 and 22-23 are epimers isolated from this plant for the first time.Compounds 11-16,18-21 are first isolated from genus Baccharis.

AIM To investigate the consistency of chemical constituents between formula granules and standard decoction of Coptidis Rhizoma.METHODS Eighteen batches of standard decoctions were prepared,after which the extraction rate and contents,transfer rates of magnolflorine,jatrorrhizine,columbamine,epiberberine,coptisine,palmatine,berberin were determined,HPLC characteristic chromatograms were established.RESULTS There were 11 common peaks in the characteristic chromatograms of 18 batches of standard decoctions and 24 batches of formula granules with the similarities of 0.861-1.000,which were clusterd into two categories.The formula granules and standard decoction demonstrated approximated extraction rate and contents,transfer rates of index constituents.CONCLUSION The chemical constituents between formula granules and standard decoction of Coptidis Rhizoma display good consistency,which can provide references for the quality control,process research and clinical application of the former.

Triterpenoids widely exist in nature,displaying a variety of pharmacological activities.Determining triterpenoids in different matrices,especially in biological samples holds great significance.High-performance liquid chromatography(HPLC)has become the predominant method for triterpenoids analysis due to its exceptional analytical performance.However,due to the structural similarities among botanical samples,achieving effective separation of each triterpenoid proves challenging,necessitating significant improvements in analytical methods.Additionally,triterpenoids are characterized by a lack of ultraviolet(UV)absorption groups and chromophores,along with low ionization efficiency in mass spectrometry.Consequently,routine HPLC analysis suffers from poor sensitivity.Chemical derivatization emerges as an indispensable technique in HPLC analysis to enhance its performance.Considering the structural characteristics of triterpenoids,various derivatization reagents such as acid chlorides,rho-damines,isocyanates,sulfonic esters,and amines have been employed for the derivatization analysis of triterpenoids.This review comprehensively summarized the research progress made in derivatization strategies for HPLC detection of triterpenoids.Moreover,the limitations and challenges encountered in previous studies are discussed,and future research directions are proposed to develop more effective derivatization methods.

AIM To evaluate the quality of Beidougen Formula Granules.METHODS Fifteen batches of standard decoctions and three batches of formula granules were prepared,after which paste rate and contents,transfer rates of magnoflorine,daurisoline,dauricine were determined.HPLC specific chromatograms were established,and cluster analysis was adopted in chemical pattern recognition.RESULTS For three batches of formula granules,the paste rates were 15.1%-16.6%,the contents of magnoflorine,daurisoline,dauricine were 18.93-19.39,9.42-9.60,6.79-6.85 mg/g with the transfer rates of 34.42%-35.25%,43.81%-44.65%,27.27%-27.51%from decoction pieces to formula granules,respectively,and there were seven characteristic peaks in the specific chromatograms with the similarities of more than 0.95,which demonstrated good consistence with those of standard decoctions and accorded with related limit requirements.Fifteen batches of standard decoctions were clustered into two types,and the medicinal materials produced from Jilin,Hebei,Shangdong could be used for the preparation of formula granules.CONCLUSION This reasonable and reliable method can provide references for the quality control and clinical application of Beidougen Formula Granules.

Objective To evaluate the bioequivalence and safety of the test formulation dapagliflozin tablets(10 mg)compared to the reference formulation in healthy adult subjects under fasting and fed conditions.Methods A single-center,randomized,open-label,two-period,two-sequence,crossover study design was employed.A total of 68 subjects were enrolled,with 32 subjects in the fasting group and 36 subjects in the fed group.Each subject received a single oral dose of either the test or reference formulation 10 mg.Plasma concentrations of dapagliflozin were measured using liquid chromatography-tandem mass spectrometry(LC-MS/MS).Pharmacokinetic parameters were calculated using Phoenix WinNonlin 8.2 to assess the bioequivalence of the two formulations and their safety.Results Key pharmacokinetic parameters of the test and reference formulations in the fasting group were as follows:Cmax were(195.08±58.24)and(200.22±45.20)ng·mL-1;tmax were 0.67 and 0.67 h;AUC0_t were(553.52±97.82)and(552.47±106.07)ng·h·mL-1;AUC0-∞ were(580.40±103.79)and(579.42±111.23)ng·h·mL-1.In the fed group,the parameters were:Cmax were(123.38±39.50)and(125.80±39.05)ng·mL-1;tmaxwere 2.00 and 2.50 h;AUC0-t were(606.05±129.44)and(596.73±131.97)ng·h·mL-1;AUC0-∞ were(637.12±138.77)and(629.38±136.81)ng·h·mL-1.The 90％confidence intervals for the geometric mean ratios of Cmax,AUC0-t and AUC0-∞ for the test and reference formulations were within the bioequivalence range of 80.00％to 125.00％.The incidence of adverse drug events was 3.23％in the fasting group and 5.56％in the fed group.Conclusion The test formulation of dapagliflozin tablets is bioequivalent to the reference formulation in healthy Chinese subjects and has a good safety profile.