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.

Glutamate,norepinephrine,and their receptors com-prise the glutamatergic and norepinephrine systems,which mu-tually affect each other and play essential roles in mediating vari-ous neuropsychiatric diseases.This paper reviews the functions of N-methyl-D-aspartate receptor(NMDA-R)and α2-adrenergic receptor(α2-AR)and their functional crosstalk at the molecular level in brain in common neuropsychiatric diseases,which would benefit our understanding of neuropathophysiology of psychiatric diseases,drug development and optimization of clinical neuro-psychopharmacology.

Objective To observe the course and diameter of facial artery branches and its adjacent structures in nasolabial groove area and the positional relationship,so as to provide reference for clinicians to carry out facial cosmetic repair surgery.Methods A total of 40 adult head and neck specimens were dissected on the spot,and the course and position of the facial artery branches,facial vein and facial nerve in the nasolabial groove area were observed,their diameters were measured,and relevant data were recorded.Results There were 4 types of facial artery branches in the nasolabial groove area:type Ⅰ(upper lip type)accounted for 12.5%,type Ⅱ(nasal type)accounted for 62.5%,type Ⅲ(classical type)accounted for 20.0%,and type Ⅳ(double severe type)accounted for 5.0% .There were 4 kinds of positional relationship between the facial artery and the facial vein in the nasolabial groove area:42.5% of the orofacial artery was located on the medial side of the facial vein,32.5% of the orofacial artery was located on the lateral side of the facial vein,17.5% of the two were close to and wrapped in a fascial sheath,7.5% of the orofacial artery and the main trunk of the facial vein were crossed,and the vein was located in the deep surface of the artery.There were 3 kinds of positional relationship between the facial artery and the marginal mandibular branch of the facial nerve:87.5% of the facial artery was deep on the marginal mandibular branch of the facial nerve,7.5% of the facial artery was superficial on the marginal mandibular branch of the facial nerve,and 5.0% of the facial artery was held or surrounded by two branches of the marginal mandibular branch of the facial nerve on the superficial or deep surface.Conclusion The positional relationship among facial artery,facial vein and facial nerve in the nasolabial groove area is complicated.Familiarity with its positional relationship can avoid damaging blood vessels and nerves during the nasorabial groove surgery,reduce surgical complications and improve surgical safety.

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.

Objective:To explore the plasma metabolomic characteristics of children with transfusion-dependent thalassemia(TDT),and reveal the changes of metabolic pattern in children with TDT.Methods:23 children with TDT who received regular blood transfusion in Ganzhou Women and Children's Health Care Hospital in 2021 were selected,and 11 healthy children who underwent physical examination during the same period were selected as the control group.The routine indexes between children with TDT and the control group were compared,and then the metabolic composition of plasma samples from children with TDT and the control group was detected by liquid chromatography-mass spectrometry.An OPLS-DA model was established to perform differential analysis on the detected metabolites,and the differential metabolic pathways between the two groups were analyzed based on the differential metabolites.Results:The results of routine testing showed that the indexes of ferritin,bilirubin,total bile acid,glucose and triglycerides in children with TDT were significantly higher than those in healthy controls,while hemoglobin and total cholesterol were significantly lower(all P＜0.05).However there was no significant difference in lactate dehydrogenase between the two groups(P＞0.05).Compared with the control group,190 differential metabolites(VIP＞1)were identified in TDT children.Among them,168 compounds such as arginine,proline and glycocholic acid were significantly increased,while the other 22 compounds such as myristic acid,eleostearic acid,palmitic acid and linoleic acid were significantly decreased.The metabolic pathway analysis showed that the metabolic impact of TDT on children mainly focused on the upregulation of amino acid metabolism and downregulation of lipid metabolism.Conclusion:The amino acid and lipid metabolism in children with TDT were significantly changed compared with the healthy control group.This finding is helpful to optimize the treatment choice for children with TDT,and provides a new idea for clinical treatment.

AIM To study endophytic fungi from Scutellaria baicalensis Georgi.and the enzyme inhibitory activities of their secondary metabolites.METHODS Six different media were used to isolate and purify endophytic fungi from S.baicalensis by tissue homogenate method.The activities of secondary metabolites were evaluated by targeting different enzymes.The highly active strains were identified by molecular biology combined with morphology,and the highly active chemical components were tracked and separated by modern chromatographic separation technology.RESULTS Sixty-four endophytic fungal strains were isolated from S.baicalensis,and one hundred and twenty-eight secondary metabolites were obtained by fermentation.The samples with certain inhibitory activities against adenosine deaminase(ADA),β-lactamase and tyrosinase(TYR)accounted for 14.06%,3.91%and 18.75%,respectively.Strain HTS-23-2 showed high TYR inhibitory activity,and 99%homology with Aspergillus flavus by molecular identification.One compound was isolated from the fermentation samples and identified as kojic acid.CONCLUSION S.baicalensis harbors a rich diversity of endophytic fungi,which serve as a valuable resource for active substances.

Background The mental health status of prison officers is crucial to the efficiency, security, and stability of a prison, and it is essential to pay attention to the factors that influence their mental health. Objective To understand the mental health status of prison officers, and analyze how nature exposure affects their mental health problems and a potential mediating role of mental fatigue. Methods A cross-sectional survey was carried out from May to June 2022 among 1392 prison officers from eight prisons in a province, and a total of 1284 valid questionnaires were recovered. The Nature Exposure Scale, Mental Fatigue Scale, and Depression-Anxiety-Stress Scale were used to assess nature exposure, mental fatigue, and mental health indicators among prison officers, and to explore the effect of nature exposure on mental health problems and a potential mediating role of mental fatigue. Results The recruited prison officers showed high levels of depression, anxiety, and stress. The prevalence rates of depression, anxiety, and stress were 59.11% (759/1284), 60.67% (779/1284),and 43.93% (564/1284), respectively. The results of correlation analysis revealed that nature exposure was negatively related with mental fatigue and mental health indicators (depression, anxiety, and stress) (r_s=−0.242, −0.308, −0.235, −0.254, P<0.01), while mental fatigue was positively correlated with mental health indicators (depression, anxiety, and stress) (r_s=0.546, 0.533, 0.536, P<0.01). The PROCESS macro results showed that the level of nature exposure among prison officers negatively associated with depression, anxiety, and stress (β=−0.180, −0.104, −0.123), and mental fatigue played a mediating role, with indirect effects of −0.200, −0.192, and −0.199, respectively. Conclusion The levels of depression, anxiety, and stress of prison officers are higher than those of other occupations. Nature exposure negatively associates with depression, anxiety, and stress, that is, it may directly alleviate the mental health problems of prison officers; and it may also alleviate mental health problems by relieving mental fatigue.

BACKGROUND:Interleukin-4 can promote the osteogenic effect of bone substitute materials,but its molecular mechanism is not yet clear.Further elucidating the mechanism of interleukin-4 promoting osteogenic effect can help find safe,economical,and effective methods for the regeneration treatment of alveolar bone defects in patients. OBJECTIVE:To explore the effect of interleukin-4 intervention on polarization transformation of macrophages and osteogenic differentiation of bone marrow mesenchymal stem cells and its possible mechanism. METHODS:RAW264.7 cells in the M1 group were induced with interferon gamma + lipopolysaccharide for 24 hours.RAW264.7 cells in the interleukin-4+M1 group were induced with interferon gamma + lipopolysaccharide for 24 hours and then interleukin-4 was added for 24 hours.RAW264.7 cells in the interleukin-4+AG+M1 group were induced with interferon gamma + lipopolysaccharide for 24 hours,and then interleukin-4 and AG-490,a JAK/STAT pathway inhibitor,were added for 24 hours.After intervention,immunofluorescence staining was used to analyze the expression of inducible nitric oxide synthase and CD206,the phenotypic marker protein of macrophages.ELISA kit was used to detect the expression of interleukin-10 and tumor necrosis factor-α in the supernatant of cell culture.The gene expressions of nodular receptor protein-3(NLRP3),interleukin-1β,and caspase-1 were detected by RT-qPCR.The expression levels of tyrosine protein kinase 1(JAK1)/phosphorylated tyrosine protein kinase 1(p-JAK1),signal transduction and transcription activator 6(STAT6)/phosphorylated signal transduction and transcription activator 6(p-STAT6),NLRP3,pro-interleukin-1β and pro-caspase-1 were detected by western blot assay.Then,RAW264.7 cells in the above four groups were indirectly co-cultured with bone marrow mesenchymal stem cells by transwell for 24 hours,followed by alkaline phosphatase staining and alizarin red staining.The mRNA expressions of alkaline phosphatase,collagen type I,and osteocalcin were detected by RT-qPCR. RESULTS AND CONCLUSION:(1)Immunofluorescence and ELISA results showed that interleukin-4 intervention could promote the expression of CD206 and interleukin-10 in M2 macrophages,and inhibit the secretion of inducible nitric oxide synthase and tumor necrosis factor-α.(2)RT-qPCR results showed that interleukin-4 could suppress the expression of NLRP3,interleukin-1β,and caspase-1 mRNAs.(3)Western blot assay showed that interleukin-4 could promote the expression of JAK1/p-JAK1,STAT6/p-STAT6 and NLRP3 proteins.(4)The alkaline phosphatase staining and alizarin red staining of bone marrow mesenchymal stem cells co-cultured with the interleukin-4+M1 group were significantly enhanced,and the mRNA expressions of alkaline phosphatase,collagen type I,and osteocalcin were significantly increased.It is concluded that interleukin-4 may inhibit the activation of NLRP3 by up-regulating JAK1/STAT6 pathway,thus promoting the transformation of macrophages from M1 polarization to M2 polarization,and finally enhancing the osteogenic differentiation ability of bone marrow mesenchymal stem cells.

Background Chronic excessive exposure to fluoride can cause damage to the central nervous system and a certain degree of learning and memory impairment. However, the associated mechanism is not yet clear and further exploration is needed. Objective Using 4D unlabelled quantitative proteomics techniques to explore differentially expressed proteins and their potential mechanisms of action in chronic excessive fluoride exposure induced brain injury. Methods Twenty-four SPF-grade adult SD rats, half male and half male, were selected and divided into a control group and a fluoride group by random number table method, with 12 rats in each group. Among them, the control group drank tap water (fluorine content<1 mg·L⁻¹), the fluoride group drank sodium fluoride solution (fluorine content 10 mg·L⁻¹), and both groups were fed with ordinary mouse feed (fluoride content<0.6 mg·kg⁻¹). After 180 d of feeding, the SD rats were weighed, and then part of the brain tissue was sampled for pathological examination by hematoxylin-eosin (HE) staining and Nissl staining. The rest of the brain tissue was frozen and stored at −80 ℃. Three brain tissue samples from each group were randomly selected for proteomics detection. Differentially expressed proteins were screened and subcellular localization analysis was performed, followed by Gene Ontology (GO) function analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, cluster analysis, and protein-protein interaction analysis. Finally, Western blotting was used to detect the expression levels of key proteins extracted from the brain tissue samples. Results After 180 d of feeding, the average weight of the rats in the fluoride group was significantly lower than that in the control group (P<0.05). The brain tissue stained with HE showed no significant morphological changes in the cerebral cortex of the fluoride treated rats, and neuron loss, irregular arrangement of neurons, eosinophilic changes, and cell body pyknosis were observed in the hippocampus. The Nissl staining results showed that the staining of neurons in the cerebral cortex and hippocampus of rats exposed to fluoride decreased (Nissl bodies decreased). The proteomics results showed that a total of 6927 proteins were identified. After screening, 206 differentially expressed proteins were obtained between the control group and the fluoride group, including 96 up-regulated proteins and 110 down-regulated proteins. The differential proteins were mainly located in cytoplasm (30.6%), nucleus (27.2%), mitochondria (13.6%), plasma membrane (13.6%), and extracellular domain (11.7%). The GO analysis results showed that differentially expressed proteins mainly participated in biological processes such as iron ion transport, regulation of dopamine neuron differentiation, and negative regulation of respiratory burst in inflammatory response, exercised molecular functions such as ferrous binding, iron oxidase activity, and cytokine activity, and were located in the smooth endoplasmic reticulum membrane, fixed components of the membrane, chloride channel complexes, and other cellular components. The KEGG significantly enriched pathways included biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments. The results of differential protein-protein interaction analysis showed that the highest connectivity was found in glucose-6-phosphate isomerase (Gpi). The expression level of Gpi in the brain tissue of the rats in the fluoride group was lower than that in the control group by Western blotting (P<0.05). Conclusion Multiple differentially expressed proteins are present in the brain tissue of rats with chronic fluorosis, and their functions are related to biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments; Gpi may be involved in cerebral neurological damage caused by chronic overdose fluoride exposure.