As the target of many psychoactive drugs such as hal-lucinogens,antidepressants,anxiolytics and atypical antipsychot-ics,5-HT2A receptor has been a research hotspot in the field of neuropsychopharmacology.Some key amino acid sites of 5-HT2A receptor play an important role in maintaining the specific con-formation of receptor,coupling different G proteins,and exerci-sing corresponding specific functions.Further studies have shown that mutations of these specific amino acid sites can cause changes in the affinity and potency of the corresponding ligands.Moreover,5-HT2A receptor is a typical G-protein-coupled recep-tor,and different amino acid sites in its structural domain can in-teract with different ligands,causing corresponding dynamic structural changes of the receptor,thus affecting the receptor function.Therefore,studying the relationship between the struc-ture and function of 5-HT2A receptor and key amino acid sites is of great significance for the treatment of related psychiatric dis-eases and the design of new drugs with high efficiency and low toxicity.

In the treatment of persistent atrial fibrillation with radiofrequency ablation,it is often necessary to add the ablation of external trigger foci of pulmonary vein on the basis of annular pulmonary vein isolation,including linear ablation,BOX ablation and fragmentation potential ablation.The isthmus of mitral valve is the most important component of linear ablation,but it is difficult to reach the isthmus of mitral valve for complete blockade by conventional radiofrequency ablation.The guide catheter was transported through the inferior vena cava to the coronary sinus,and the injection of Marshall vein anhydrous ethanol for ablation could achieve epicardial and myocardial block in the mitral isthmus,and the ablation combined with the endocardial patch ablation in the mitral isthmus could significantly improve the ablation effect,but there were disadvantages such as Marshall vein and coronary vein injury,high surgical cost and long time.This paper reports a case of persistent atrial fibrillation treated by self-made perforated balloon with Marshall intravenous anhydrous ethanol combined with individualized ablation strategy.No major adverse cardiovascular events or recurrence of atrial fibrillation occurred during 6 months of follow-up after discharge.

The prevalence of Lyme disease in endogenous populations in Urumqi,Xinjiang was investigated.In total,795 serum samples were collected from residents of three townships in the surrounding area of Urumqi City from 2022 to 2023,which included 383 from Lucaogou Town,145 from Shuixigou Town,and,267 from Tori Township.Serum levels of IgG and IgM antibodies were screened with an enzyme linked immunosorbent assay(ELISA)and confirmed by western blot(WB)analysis.Clinical data of WB-positive indi-viduals were collected and comprehensive analysis was con-ducted for case diagnosis.The chi square test was used for statistical analysis of the results and the P＜0.05 was consid-ered statistically significant.In total,110(13.84％)of 795 samples were positive.The positivity rates was higher in females than males[16.26％(73/449)vs.10.69％(37/346),x2=5.076,P=0.024],while there was no significant difference among age groups(x2=2.569,P=0.766).The positivity rates for serum antibodies in Shuixigou Town,Lucaogou Town,and Tuoli Township were 17.98％(48/267),14.48％(21/145),and 10.70％(41/383),respectively,with a significantly higher rate in Tuoli Township than Lucaogou Town(x2=7.041,P=0.008).Of 110 individuals who were initially positive for IgG and IgM antibodies with the ELISA,82(10.31％)were con-firmed positive by WB analysis.In total,20(2.52％)patients were diagnosed with Lyme disease based on clinical manifesta-tions.Lyme disease is epidemic among the population in Urumqi,as the infection rate is higher than the national average.Hence,continued surveillance is recommended for prevention of Lyme disease.

Objective:To investigate the effect of genetic polymorphism of MTHFR C677T (rs1801133) on methotrexate (MTX) related toxicity in pediatric mature B-cell lymphoma patients. Methods:Fifty-eight intermediate and high risk patients under 18 years of age with mature B-cell lymphoma who received 5 g/m2 MTX (24 h intravenous infusion) in Sun Yat-sen University Cancer Center from August 2014 to December 2021 were included,and their toxicity of high-dose MTX (HD-MTX) were monitored and analyzed. Results:Among the 58 pediatric patients,the number of CC,CT,and TT genotypes for MTHFR C677T was 33,19 and 6,respectively. A total of 101 courses of HD-MTX therapy were counted,of which plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion were observed in 35 courses,≤0.2 μmol/L in 66 courses. Inter-group comparison showed that plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion increased the risk of developing oral mucositis (P<0.05). Compared with wild-type (CC genotype),patients in the mutant group (CT+TT genotype) were more likely to develop myelosuppression,manifested as anemia,leucopenia,neutropenia and thrombocytopenia. However,plasma MTX level at 48 h was not associated with MTHFR C677T gene polymorphism. Conclusion:The risk of developing oral mucositis in children with mature B-cell lymphoma is associated with plasma MTX concentration. Polymorphism of MTHFR C677T gene is not related to plasma MTX concentration in children with mature B-cell lymphoma,but is related to grade Ⅲ to Ⅳ hematological toxicity.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. 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 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective To investigate the effect of quality control circle(QCC)activities on reducing the incidence of non-failure alarms of heated humidifiers in the intensive care unit(ICU).Methods Firstly,a QC circle team was formed,and the activity theme of reducing the incidence of non-faulty alarms of heated humidifiers in the ICU was selected to inves-tigate the current status of the use of heated humidifiers in the ICU during the period of December 1-15,2021,and to set improvement goals.Secondly,pareto charts and fishbone diagrams were drawn to analyze the causes for the occurrence of non-faulty alarms.Finally,the countermeasures were formulated and implemented according to the PDCA principle.The inciden-ces of non-faulty alarms of heated humidifiers and the comprehensive capabilities of the circle members were compared before and after the implementation of the QC circle activities.Results After the implementation of the QCC activities,the incidence of non-failure alarms of heated humidifiers decreased from 48.57％to 8.23％,the target achievement rate was 119.7％,the progress rate was 83.06％,and the comprehensive capabilities of circle members were improved obviously.Conclusion The QCC activities effectively reduces the incidence of non-failure alarms of heated humidifiers in the ICU,and thus is worthy promoting for standardizing medical equipment management.[Chinese Medical Equipment Journal,2024,45(6):87-92]

Objective To construct a set of graduation internship curriculum system suitable for undergraduate students majoring in biomedical engineering to facilitate standardizing the curriculum system of biomedical engineering major.Methods An initial version of the curriculum system was established with the way of letter and the methods of questionnaire survey,Delphi,expert interview and expert brainstorming;then the initial version was adjusted and refined using 2 rounds of expert consultation to form a set of curriculum system for graduation internship for undergraduate students majoring in biomedical engineering,and the curriculum system was validated.Results The curriculum system included 5 first-level catalogs,11 second-level catalogs and 39 third-level catalogs;the 36 third-level catalogs had a curriculum compliance rate of 0.85 to 0.97.Conclusion The curriculum system constructed can be used for graduation internship of biomedical engineering undergraduates,and references are provided for developing standardized and generally applicable graduation internship curriculum system for biomedical engineering undergraduates.[Chinese Medical Equipment Journal,2024,45(9):89-94]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Hepatic sinusoidal obstruction syndrome(HSOS),a toxic liver injury,can lead to multiple organ failure in severe cases and is even fatal.Early diagnosis is of great significance for the selection of treatment regimens and prognosis.Currently,ultrasound,as the preferred diagnostic method for liver diseases,has been recommended in expert consensus and criteria for the diagnosis of HSOS.However,there are no definitive ima-ging diagnostic standards.This paper summarizes the sonographic features of ultrasound and new ultrasound tech-nologies in HSOS research.Analyzing the characteristic sonographic images from gray-scale ultrasonography,Doppler ultrasonography,ultrasound elastography,and contrast-enhanced ultrasonography at different stages of the dis-ease enables the establishment and refining of the corresponding imaging diagnostic standards and provides effec-tive auxiliary examination methods for the early diagnosis and differential diagnosis of HSOS.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. 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 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.