Background With the progression of industrialization, an increasing number of emerging contaminants are entering aquatic environments, posing significant threats to the safety of drinking water. Therefore, establishing a system for identifying unknown hazardous factors and implementing safety warning mechanisms for drinking water is of paramount importance. Among these efforts, non-target screening plays a critical role, but its effectiveness is largely constrained by the scope of coverage of sample pre-treatment methods. Objective To integrate modern chromatography/mass spectrometry techniques with advanced data mining methods to develop a non-discriminatory sample pre-treatment method for comprehensive enrichment of unknown contaminants in drinking water, laying a technical foundation for the discovery and identification of unknown organic hazardous factors in drinking water. Methods A non-discriminatory pre-treatment method based on supramolecular and solid-phase extraction was developed. The final target compounds including 333 pesticides, 194 pharmaceuticals and personal care products (PPCPs), and 59 per- and polyfluoroalkyl substances (PFASs) were used for optimizing the pre-treatment method, confirming its coverage. The impacts of different eluents on the absolute recovery rates of target compounds were compared to select the conditions with the highest recovery for sample pre-treatment. The effects of different supramolecular solvents and salt concentrations on target compound recovery were also evaluated to determine the most suitable solvent and salt concentration. Results The solid-phase extraction elution solvents, supramolecular extraction solvents, and salt concentrations were optimized based on the target compound recovery rates. The optimal recovery conditions were achieved using 2 mL methanol, 2 mL methanol (containing 1% formic acid), 2 mL ethyl acetate, 2 mL dichloromethane, hexanediol supramolecular solvent, and 426 mg salt. The detection method developed based on these conditions showed a good linear relationship for all target compounds in the range of 0.1-100.0 ng·mL⁻¹, with R² > 0.99. The method’s limit of detection ranged from 0.01 ng⁻¹ to 0.95 ng⁻¹, and 95% of target compounds were recovered in the range of 20%-120%, with relative standard deviation (RSD) less than 30%, indicating good precision. Conclusion The combined pre-treatment method of solid-phase extraction and supramolecular solvent extraction can effectively enrich contaminants in drinking water across low, medium, and high polarities, enabling broad-spectrum enrichment of diverse trace contaminants in drinking water. It provides technical support for broad-spectrum, high-throughput screening and identification of organic pollutants in drinking water, and also serves as a reference for establishing urban drinking water public safety warning systems.

Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive dysfunction and behavioral impairment, and there is a lack of effective drugs to treat AD clinically. Existing medications for the treatment of AD, such as Tacrine, Donepezil, Rivastigmine, and Aducanumab, only serve to delay symptoms and but not cure disease. To add insult to injury, these medications are associated with very serious adverse effects. Therefore, it is urgent to explore effective therapeutic drugs for AD. Recently, studies have shown that a variety of enzyme inhibitors, such as cholinesterase inhibitors, monoamine oxidase (MAO)inhibitors, secretase inhibitors, can ameliorate cholinergic system dysfunction, Aβ production and deposition, Tau protein hyperphosphorylation, oxidative stress damage, and the decline of synaptic plasticity, thereby improving AD symptoms and cognitive function. Some plant extracts from natural sources, such as Umbelliferone, Aaptamine, Medha Plus, have the ability to inhibit cholinesterase activity and act to improve learning and cognition. Isochromanone derivatives incorporating the donepezil pharmacophore bind to the catalytic active site (CAS) and peripheral anionic site (PAS) sites of acetylcholinesterase (AChE), which can inhibit AChE activity and ameliorate cholinergic system disorders. A compound called Rosmarinic acid which is found in the Lamiaceae can inhibit monoamine oxidase, increase monoamine levels in the brain, and reduce Aβ deposition. Compounds obtained by hybridization of coumarin derivatives and hydroxypyridinones can inhibit MAO-B activity and attenuate oxidative stress damage. Quinoline derivatives which inhibit the activation of AChE and MAO-B can reduce Aβ burden and promote learning and memory of mice. The compound derived from the combination of propargyl and tacrine retains the inhibitory capacity of tacrine towards cholinesterase, and also inhibits the activity of MAO by binding to the FAD cofactor of monoamine oxidase. A series of hybrids, obtained by an amide linker of chromone in combine with the benzylpiperidine moieties of donepezil, have a favorable safety profile of both cholinesterase and monoamine oxidase inhibitory activity. Single domain antibodies (such as AAV-VHH) targeted the inhibition of BACE1 can reduce Aβ production and deposition as well as the levels of inflammatory cells, which ultimately improve synaptic plasticity. 3-O-trans-p-coumaroyl maslinic acid from the extract of Ligustrum lucidum can specifically inhibit the activity of γ-secretase, thereby rescuing the long-term potentiation and enhancing synaptic plasticity in APP/PS1 mice. Inhibiting γ-secretase activity which leads to the decline of inflammatory factors (such as IFN-γ, IL-8) not only directly improves the pathology of AD, but also reduces Aβ production. Melatonin reduces the transcriptional expression of GSK-3β mRNA, thereby decreasing the levels of GSK-3β and reducing the phosphorylation induced by GSK-3β. Hydrogen sulfide can inhibitGSK-3β activity via sulfhydration of the Cys218 site of GSK-3β, resulting in the suppression of Tau protein hyperphosphorylation, which ameliorate the motor deficits and cognitive impairment in mice with AD. This article reviews enzyme inhibitors and conformational optimization of enzyme inhibitors targeting the regulation of cholinesterase, monoamine oxidase, secretase, and GSK-3β. We are hoping to provide a comprehensive overview of drug development in the enzyme inhibitors, which may be useful in treating AD.

Objective To investigate the clinical effects and pregnancy outcomes of using luteal phase long protocol and GnRH antagonist protocol in patients with polycystic ovary syndrome(PCOS)who have failed their first GnRH antagonist protocol therapy.Methods The clinical data of 163 PCOS patients who underwent IVF/ICSI-ET were retrieved.After the failure of their first GnRH antagonist protocol treatment,they were divided into two groups in the second controlled ovarian hyperstimulation(COH)cycle:Luteal phase long protocol group(n=95)and Gn-RH antagonist protocol group(n=68).A retrospective analysis and comparison of basic clinical data,clinical and laboratory indicators,and pregnancy outcomes between two groups were conducted.Results ① There was no sta-tistically significant difference in basic clinical indicators between two group except LH.② Compared the first and second cycle treatments of patients in the luteal phase long protocol group,the initiation dose of gonadotropin(Gn),total number of Gn days,total Gn usage,estradiol(E2)on the day of hCG injection,number of retrieved eggs,oocyte maturation rate,2PN fertilization rate,2PN cleavage rate,blastocyst formation rate,high-quality blas-tocyst formation rate,and moderate to severe OHSS rate were significantly higher than those in the first GnRH an-tagonist cycle(P＜0.05).The GnRH antagonist protocol group also showed similar improvements.③ The com-parison of the second COH cycle between two groups showed that the total number of Gn days,total Gn usage,and total Gn cost in the luteal phase long protocol group were significantly higher(P＜0.05),while the E2 and LH on the day of hCG injection,and the maturation rate of eggs were significantly lower than those in the GnRH antagonist protocol group(P＜0.05).However,there was no statistically significant difference in the number of retrieved eggs,2PN fertilization,2PN cleavage,blastocyst formation rate,high-quality blastocyst formation rate,and OHSS rate between the two groups;④ The comparison of fresh transplantation cycles for the second COH cycle between the two groups showed that the luteal phase long protocol fresh transplantation rate,implantation rate,clinical preg-nancy rate,and live birth rate were slightly higher than those of the GnRH antagonist protocol group,but the differ-ence was not statistically significant.Comparing the outcomes of pregnancy following the initial frozen-thawed em-bryo transfer(FET)between two groups,the biochemical pregnancy rate and clinical pregnancy rate of the GnRH antagonist protocol group were higher than those of the luteal phase long protocol group(P＜0.05).However,no significant statistical variations were found in implantation rate,live birth rate,neonatal gestational age,and birth weight.Conclusion For PCOS patients who fail the first GnRH antagonist protocol,an appropriate increase in the initiating dose and usage of Gn can achieve satisfactory pregnancy outcomes with both protocols.Compared with change to a luteal phase long protocol,reusing the GnRH antagonist protocol still maintains its long-standing advan-tages,such as shorter total Gn days,lower costs,and better patient compliance.

Objective This study was aimed to investigate the impact of probiotics on regulating the ROS/JNK signaling pathway their underlying mechanism of action in the treatment of metabolic associated fatty liver disease.Methods Male C57BL/6 mice were randomly divided into three groups:control,probiotics,and model groups.Serum levels of ALT,AST,TC,and TG were detected.Moreover,the pathological changes of the liver and ileum tissues were observed by hematoxylin and eosin(H&E)staining,and the content of reactive oxygen species(ROS)in liver tissues was determined.In addition,the levels of D-lactic acid and serum and small intestine diamine oxidase were measured to evaluate the effects of probiotics on the intestinal tract of MAFLD mice.Results Mice in the probiotic group were treated with probiotic intervention,compared with model group,mice hepatic lobule structure was complete,hepatic steatosis in cells and inflammatory cells infiltration were relieved.After C57BL/6 mice were fed the MCD diet,the body weight of the model group was significantly lower than that of the control group,showing poor mental state.After 4 weeks of probiotics treatment,the body weight of mice in the probiotics group was higher than that in the model group,and their mental state was better than that in the model group.Biochemical analysis showed that the levels of ALT,AST,TC,TG,D-lac,serum and small intestinal DAO and ROS in liver in the model group were considerably higher than those in the control group.After 4 weeks of probiotics intervention,serum ALT,AST,TC,TG,D-lac,DAO and ROS levels decreased compared with the model group(P＜0.05).Western blot analysis showed that the expression levels of p-JNk,Caspase-3,Bax in the model group were up-regulated,and the expression level of intestinal tight junction protein ZO-1 was down-regulated compared with the control group.After 4 weeks of probiotics intervention,the expression levels of p-JNK,caspase-3,Bax in the probiotics group were down-regulated compared with that in the model group,while the expression level of intestinal tight junction protein ZO-1 was up-regulated compared with that in the model group(P＜0.05).PCR analysis showed that the expression levels of Bax and Caspase-3 in the model group were significantly increased,while the expression levels of Bax and Caspase-3 in the probiotic group were significantly decreased compared with those in the model group(P＜0.05).Immunohistochemistry analysis showed that the expression levels of P-JNk,Caspase-3 and Bax in the liver of mice in the probiotic group were lower than those in the model group(P＜0.05).The pathological results in our investigation showed that the ileum mucosa in the control group was intact,and the intestinal villi were complete and neatly arranged,without any infiltration of inflammatory cells.However,in the model group the ileum mucosal structure was seriously damaged,with loose and disorderly villi arrangement.Importantly,the ileum mucosa in the probiotic group had fewer injuries and the villi were arranged more neatly.Besides,the ileum tissue of the control group had the lowest Chiu's score range(0-1),whereas that of the model group was 3-4,and the one of the probiotic group was 1-2.Conclusion The increased expression of P-JNk,ROS,Caspase-3 and Bax in MAFLD indicates that it is associated with the onset of MAFLD.The use of probiotics can improve the histological and serological indicators of MAFLD.Western blot,PCR and immunohistochemical results confirmed that probiotics can regulate the expression of factors related to ROS/JNK signaling pathway,reduce oxidative stress and inhibit cell apoptosis to achieve the goal of treating MAFLD.

Objective To compare the repair effects of different doses of human umbilical cord mesenchymal stem cells(hUC-MSCs)on white matter injury(WMI)in neonatal rats.Methods Two-day-old Sprague-Dawley neonatal rats were randomly divided into five groups:sham operation group,WMI group,and hUC-MSCs groups(low dose,medium dose,and high dose),with 24 rats in each group.Twenty-four hours after successful establishment of the neonatal rat white matter injury model,the WMI group was injected with sterile PBS via the lateral ventricle,while the hUC-MSCs groups received injections of hUC-MSCs at different doses.At 14 and 21 days post-modeling,hematoxylin and eosin staining was used to observe pathological changes in the tissues around the lateral ventricles.Real-time quantitative polymerase chain reaction was used to detect the quantitative expression of myelin basic protein(MBP)and glial fibrillary acidic protein(GFAP)mRNA in the brain tissue.Immunohistochemistry was employed to observe the expression levels of GFAP and neuron-specific nuclear protein(NeuN)in the tissues around the lateral ventricles.TUNEL staining was used to observe cell apoptosis in the tissues around the lateral ventricles.At 21 days post-modeling,the Morris water maze test was used to observe the spatial learning and memory capabilities of the neonatal rats.Results At 14 and 21 days post-modeling,numerous cells with nuclear shrinkage and rupture,as well as disordered arrangement of nerve fibers,were observed in the tissues around the lateral ventricles of the WMI group and the low dose group.Compared with the WMI group,the medium and high dose groups showed alleviated pathological changes;the arrangement of nerve fibers in the medium dose group was relatively more orderly compared with the high dose group.Compared with the WMI group,there was no significant difference in the expression levels of MBP and GFAP mRNA in the low dose group(P＞0.05),while the expression levels of MBP mRNA increased and GFAP mRNA decreased in the medium and high dose groups.The expression level of MBP mRNA in the medium dose group was higher than that in the high dose group,and the expression level of GFAP mRNA in the medium dose group was lower than that in the high dose group(P＜0.05).Compared with the WMI group,there was no significant difference in the protein expression of GFAP and NeuN in the low dose group(P＞0.05),while the expression of NeuN protein increased and GFAP protein decreased in the medium and high dose groups.The expression of NeuN protein in the medium dose group was higher than that in the high dose group,and the expression of GFAP protein in the medium dose group was lower than that in the high dose group(P＜0.05).Compared with the WMI group,there was no significant difference in the number of apoptotic cells in the low dose group(P＞0.05),while the number of apoptotic cells in the medium and high dose groups was less than that in the WMI group,and the number of apoptotic cells in the medium dose group was less than that in the high dose group(P＜0.05).Compared with the WMI group,there was no significant difference in the escape latency time in the low dose group(P＞0.05);starting from the third day of the latency period,the escape latency time in the medium dose group was less than that in the WMI group(P＜0.05).The medium and high dose groups crossed the platform more times than the WMI group(P＜0.05).Conclusions Low dose hUC-MSCs may yield unsatisfactory repair effects on WMI in neonatal rats,while medium and high doses of hUC-MSCs have significant repair effects,with the medium dose demonstrating superior efficacy.[Chinese Journal of Contemporary Pediatrics,2024,26(4):394-402]

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.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.