Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

AIM: To evaluate the performance of three distinct large language models(LLM), including GPT-3.5, GPT-4, and PaLM2, in responding to queries within the field of ophthalmology, and to compare their performance with three different levels of medical professionals: medical undergraduates, master of medicine, and attending physicians.METHODS: A total of 100 ophthalmic multiple-choice tests, which covered ophthalmic basic knowledge, clinical knowledge, ophthalmic examination and diagnostic methods, and treatment for ocular disease, were conducted on three different kinds of LLM and three different levels of medical professionals(9 undergraduates, 6 postgraduates and 3 attending physicians), respectively. The performance of LLM was comprehensively evaluated from the aspects of mean scores, consistency and confidence of response, and it was compared with human.RESULTS: Notably, each LLM surpassed the average performance of undergraduate medical students(GPT-4:56, GPT-3.5:42, PaLM2:47, undergraduate students:40). Specifically, performance of GPT-3.5 and PaLM2 was slightly lower than those of master's students(51), while GPT-4 exhibited a performance comparable to attending physicians(62). Furthermore, GPT-4 showed significantly higher response consistency and self-confidence compared with GPT-3.5 and PaLM2.CONCLUSION: LLM represented by GPT-4 performs well in the field of ophthalmology, and the LLM model can provide clinical decision-making and teaching aids for clinicians and medical education.

2-(4-Methylthiazol-5-yl) ethyl nitrate hydrochloride (W1302) is a nitro containing derivative of clomethiazole, which is a novel neuroprotective agent with both carbon monoxide (NO) donor and weak γ-aminobutyric acid type A (GABA_A) receptor allosteric regulatory excitatory effect. The current study used a rat model of transient middle cerebral arteryocclusion (tMCAO) brain injury to evaluate the therapeutic effect of W1302 on ischemic stroke and explore its potential mechanisms of action. This experiment has been reviewed and approved by the Laboratory Animal Management and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences (ethical review forms No. 620, 632, 5013). The results showed that gavage administration of 1, 3, and 10 mg·kg^-1 of W1302 can significantly reduce the volume of cerebral infarction in rats with ischemia for 2 h and reperfusion for 24 h, and the therapeutic effect was better than that of 200 mg·kg^-1 of DL-3n-butylphthalide. W1302 significantly increased NO levels in blood and brain tissue. It increased cerebral blood flow and brain adenosine triphosphate (ATP) content after reperfusion, as well as, inhibited the expressions of inflammatory factors tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in brain tissue. The time window of W1302 was between 120-180 min after ischemia. These research results demonstrated that W1302 could increase NO release, dilate blood vessels, and increase cerebral blood flow, improve energy supply to brain tissue and increase ATP levels, and inhibit neuro-inflammation, which playing the protective roles in tMCAO stroke model rats. This provides theoretical support for the clinical application of W1302 in the treatment of ischemic stroke.

Objective To analyze the metabolomics characteristics of chronic atrophic gastritis(CAG)patients with liver-stomach qi stagnation and spleen-stomach weakness syndromes based on non-targeted metabolomics technology,and to identify the serum differentiated metabolites related to traditional Chinese medicine(TCM)syndrome of CAG patients,so as to provide a reference for the objectification of syndrome differentiation.Methods Sixty patients with CAG were included,including 30 cases of liver-stomach qi stagnation syndrome and 30 cases of spleen-stomach weakness syndrome.Fasting blood of 5 mL was collected from the cubital vein of patients in the two groups,and the serum levels of metabolites were detected by ultra-high-performance liquid chromatography-mass spectrometry(UPLC-MS)methods.The principal component analysis(PCA),orthogonal partial least squares-discriminant analysis(OPLS-DA),and cluster analysis were used to screen the differentiated metabolites of CAG patients with liver-stomach qi stagnation syndrome and spleen-stomach weakness syndrome.Finally,metabolite pathway analysis was performed for the obtained differentiated metabolites using the KEGG database.Results The results for the screening of differentiated metabolites showed that significant differences of amino acid derivatives and small peptide metabolites were presented between CAG patients with liver-stomach qi stagnation syndrome and CAG patients with spleen-stomach weakness syndrome.The amino acid derivatives consisted of N-acetylglycine,histamine,O-phosphoserine,selenomethylselenocysteine,and methyl-tyrosine.And the small peptide metabolites consisted of tyrosine-leucine-phenylalanine,histidine-alanine-glutamate-lysine,L-asparagine-L-proline-L-serine,and L-isoleucine-L-isoleucine.Conclusion Differences in amino acid metabolism exist between CAG patients with liver-stomach qi stagnation syndrome and those with spleen-stomach weakness syndrome,and metabolites such as N-acetylglycine,intermethyltyrosine,and O-phosphoserine may be the potential biomarkers for distinguishing liver-stomach qi stagnation syndrome from spleen-stomach weakness syndrome in CAG patients.

Multisystem inflammatory syndrome in children(MIS-C)is a complex syndrome characterized by multi-organ involvement that has emerged in the context of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)outbreak.The clinical presentation of MIS-C is similar to Kawasaki disease but predominantly presents with fever and gastrointestinal symptoms,and severe cases can involve toxic shock and cardiac dysfunction.Epidemiological findings indicate that the majority of MIS-C patients test positive for SARS-CoV-2 antibodies.The pathogenesis and pathophysiology of MIS-C remain unclear,though immune dysregulation following SARS-CoV-2 infection is considered a major contributing factor.Current treatment approaches for MIS-C primarily involve intravenous immunoglobulin therapy and symptomatic supportive care.This review article provides a comprehensive overview of the definition,epidemiology,pathogenesis,clinical presentation,diagnosis,treatment,and prognosis of MIS-C.

Flubromazolam(Flub)is a novel psychoactive substance of benzodiazepines and the mechanism underlying its addiction still remains elusive.This study investigated the reward effect of Flub using conditioned place preference(CPP)mouse model.The neuronal activity was evaluated by c-Fos expression,and the neural circuit was tracked by virus tracing.This study also investigated the regulatory effect of neural circuits on Flub-induced reward effects through chemogenetic approach.The results showed that,at the dose of 3 mg/kg,Flub significantly increased CPP score and c-Fos expression in dopaminergic(DA)neurons of ventral tegmental area(VTA).Inhibition of VTA dopaminergic neuron activity dramatically decreased Flub-induced CPP score.Virus tracing verified GABAergic neuronal projection of medial rostrum tegmental nucleus(RMTg)to VTA dopaminergic neurons.Activation of RMTgGABA→VTADA circuit or blockade of benzodiazepine receptors(BZR)in RMTg significantly decreased Flub-induced CPP score.These results indicate that Flub produced reward effect via BZR-mediated RMTgGABA→VTADA circuit.

Objective This study aimed to comprehensively analyze and compare the clinicopathological features and prognosis of Chinese patients with human epidermal growth factor receptor 2(HER2)-low early breast cancer(BC)and HER2-IHC0 BC. Methods Patients diagnosed with HER2-negative BC(N=999)at our institution between January 2011 and December 2015 formed our study population.Clinicopathological characteristics,association between estrogen receptor(ER)expression and HER2-low,and evolution of HER2 immunohistochemical(IHC)score were assessed.Kaplan-Meier method and log-rank test were used to compare the long-term survival outcomes(5-year follow-up)between the HER2-IHC0 and HER2-low groups. Results HER2-low BC group tended to demonstrate high expression of ER and more progesterone receptor(PgR)positivity than HER2-IHC0 BC group(P<0.001).The rate of HER2-low status increased with increasing ER expression levels(Mantel-Haenszel χ2 test,P<0.001,Pearson's R=0.159,P<0.001).Survival analysis revealed a significantly longer overall survival(OS)in HER2-low BC group than in HER2-IHC0 group(P=0.007)in the whole cohort and the hormone receptor(HR)-negative group.There were no significant differences between the two groups in terms of disease-free survival(DFS).The discordance rate of HER2 IHC scores between primary and metastatic sites was 36.84%. Conclusion HER2-low BC may not be regarded as a unique BC group in this population-based study due to similar clinicopathological features and prognostic roles.

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 distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.