ObjectiveThis study explores the methods of lung tissue extraction and fixation required for pathological studies of fetal rats, based on the unique physiological structure of fetal rat lung tissue and existing lung tissue fixation techniques for adult rats. MethodsSix pregnant adult SD rats at 20.5 days of gestation were subjected to cesarean section to obtain fetal rats. Four healthy fetal rats with similar body weight, vital signs, and respiratory status were selected from each pregnant rat, and they were randomly divided into the following groups using a random number table: direct lung infiltration group, lung infiltration group after intratracheal infusion, whole-body infiltration group of fetal rats, and whole-body infiltration group after intratracheal infusion of fetal rats. To systematically compare and analyze the anatomical morphology under different fixation methods, lung tissues from four groups of fetal rats were harvested, perfused, and fixed, and the gross morphology of lung tissues in each group was observed. Paraffin sections were prepared and stained with Hematoxylin-Eosin (H&E). The histological morphology of the whole lung, alveoli, and bronchi was further examined under optical microscopy. ResultsIn the direct lung infiltration group, the hilar structures were unclear, lung lobation was indistinct, the shape was irregular, lung cavities were small, and alveoli and bronchi were shrunken. In the lung infiltration group after intratracheal infusion, the hilar structures were clear, lobation was pronounced, the shape was regular, lung cavities were large, and alveoli and bronchi were full. Both the whole-body infiltration group and whole-body infiltration group after intratracheal infusion of fetal rats exhibited visible lungs, hearts, skins, and other organs. The lung tissues of both groups showed obvious lobulation, irregular shape, and damage at the margins of lung lobes. In the whole-body infiltration group, the thoracic cavities of the fetus were flattened, lung cavities were small, and alveoli and bronchi were shrunken. In the whole-body infiltration group after intratracheal infusion of fetal rats, the fetal thoracic cavities were full, lung cavities were large, and alveoli and bronchi were relatively full. ConclusionThe lung infiltration after intratracheal infusion method for fetal rat lung tissue fixation outperforms direct lung infiltration, whole-body infiltration of fetal rats, and whole-body infiltration after intratracheal infusion of fetal rats in terms of preservation of the lung tissue's original morphology, paraffin sectioning, staining, and pathological observation and analysis. The embedding, sectioning, and staining processes are also simple and save consumables. Therefore, intratracheal infusion followed by lung infiltration method is recommended for fixation in histopathological observation of fetal rat lung tissue.

Objective To investigate the current situation and influencing factors of latent tuberculosis infection(LTBI)among close contacts of positive etiology pulmonary tuberculosis(PTB)patients,provide basis for formula-ting intervention measures for LTBI.Methods A multi-stage stratified cluster random sampling method was used to select close contacts of positive etiology PTB patients from 39 districts and counties in Chongqing City as the study objects.Demographic information was collected by questionnaire survey and the infection of Mycobacterium tuberculosis was detected by interferon gamma release assay(IGRA).The influencing factors of LTBI were analyzed by x2 test and binary logistic regression model.Results A total of 2 591 close contacts were included,the male to female ratio was 0.69∶1,with the mean age of(35.72±16.64)years.1 058 cases of LTBI were detected,Myco-bacterium tuberculosis latent infection rate was 40.83％.Univariate analysis showed that the infection rate was dif-ferent among peoples of different age,body mass index(BMI),occupation,education level,marital status,wheth-er they had chronic disease or major surgery history,whether they lived together with the indicator case,and whether the cumulative contact time with the indicator case ≥250 hours,difference were all statistically significant(all P＜0.05);infection rate presented increased trend with the increase of age and BMI(both P＜0.001),and decreased trend with the increase of education(P＜0.05).Logistic regression analysis showed that age 45-54 years old(OR=1.951,95％CI:1.031-3.693),age 55-64 years old(OR=2.473,95％CI:1.279-4.781),other occupations(OR=0.530,95％CI:0.292-0.964),teachers(OR=0.439,95％CI:0.242-0.794),students(OR=0.445,95％CI:0.233-0.851),junior high school education or below(OR=1.412,95％CI:1.025-1.944),BMI＜18.5 kg/m2(OR=0.762,95％CI:0.586-0.991),co-living with indicator cases(OR=1.621,95％CI1.316-1.997)and cumu-lative contact time with indicator cases ≥250 hours(OR=1.292,95％CI:1.083-1.540)were the influential fac-tors for LTBI(all P＜0.05).Conclusion The close contacts with positive etiology PTB have a high latent infection rate of Mycobacterium tuberculosis,and it is necessary to pay attention to close contacts of high age,farmers,and frequent contact with patients,and take timely targeted interventions to reduce the risk of occurrence of disease.

Objective To predict the potential suitable growth areas of Epimedium brevicornu Maxim.under current climate conditions in China;To provide basis for the sustainable utilization of Epimedium brevicornu Maxim.resources and production planning.Methods Based on 267 screened species distribution data of Epimedium brevicornu Maxim.and 8 environmental factors,the MaxEnt parameters were optimized by the R language kuenm package.The main environmental factors that affect the distribution of Epimedium brevicornu Maxim.was analyzed and its potential distribution range was predicted.Results The omission rate of the optimal model operation results was 0.044 8,AICc=6 409.884 5,AUC=0.986,indicating a high accuracy of the model.Based on the contribution rate of environmental factors and the knife cut method,it was indicated that the key environmental factors affecting the current distribution of Epimedium brevicornu Maxim.were mainly the average precipitation in July,the average highest temperature in February,the average precipitation in September,the coldest season precipitation,the coefficient of variation of precipitation,the standard deviation of seasonal temperature changes,and the warmest season precipitation.The simulation results showed that the total suitable area for Epimedium brevicornu Maxim.in China under current climate conditions was approximately 221.14×104 km2,concentrated in the central and central southern regions of China.The area of the high suitability zone was approximately 23.13×104 km2;the area of the suitable growth zone was approximately 73.78×104 km2;the area of low suitability zone was approximately 124.22×104 km2.Conclusion This study provides a basis and reference for the artificial cultivation planning and sustainable utilization of Epimedium brevicornu Maxim.resources.

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.

AIM To investigate the effect of Wendan Decoction on nerve injury in a mouse model of sleep disorders and its mechanism.METHODS A mouse model of insomnia was established by the modified multiple platform sleep deprivation method.After successful modeling,the mice were randomly divided into the model group,the estazolam tablet group(0.15 mg/kg)and the low-dose and high-dose Wendan Decoction groups(12.5,50 g/kg),with 6 mice in each group,in contrast to the 6 mice of the control group.After 7 days of drug intervention,the mice had their changes of cerebral cortex,hippocampal CA1 area and hypothalamus observed by HE staining;their neuronal damage observed by Nissl staining;their levels of neurofilament light chain(NEFL),neuron-specific enolase(NSE),S100 calcium-binding protein B(S100B),tumor necrosis factor(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β)in brain tissue and serum detected by ELISA;their cerebral expression of glial fibrillary acidic protein(GFAP)detected by immunohistochemical method;and their cerebral expressions of GFAP,phosphorylated IκB kinase β(p-IKKβ)and phosphorylated nuclear transcription factor-κB(p-NF-κB)detected by Western blot.RESULTS Compared with the model group,the high-dose Wendan Decoction group displayed increased number of neurons,complete and neatly arranged structure;decreased number of neurons with nuclear shrinkage and deformation;increased Nissl bodies,decreased levels of NEFL,NSE,S100B,TNF-α,IL-6 and IL-1β in serum and brain tissue(P＜0.01);decreased cerebral expression of GFAP(P＜0.01);and decreased phosphorylation levels of cerebral p-IKKβ and p-NF-κB(P＜0.01).CONCLUSION Wendan Decoction can reduce the nerve damage and the expression of proinflammatory mediator in sleep disorders mice,and the mechanism may be related to the inhibited activation of IKKβ/NF-κB pathway.

Objective To explore the acupoint selection rules of acupuncture treatment for cerebellar ataxia using data mining techniques.Methods Taking the related literature of acupuncture treatment of cerebellar ataxia as the retrieval content,the computer retrieval of China National Knowledge Internet(CNKI),China Biomedical Literature Database(SinoMed),Wanfang Data Knowledge Service Platform(Wanfang),China Science and Technology Journal Database(VIP),American Biomedical Information Retrieval System(PubMed)and other major databases.The eligible acupoints in the literature were entered into the Microsoft Excel 2021 software table to establish a database of acupoints frequency,meridian tropism,specific acupoints,distribution sites and other information for acupuncture treatment of cerebellar ataxia.SPSS Modeler 18.0 Apriori algorithm,SPSS Statistics 25.0 and SPSS Modeler 18.0 Web complex network were used to analyze the association rules of the included prescription acupoints,Ward cluster analysis and draw the tree diagram and the Web network diagram of high-frequency acupoints and core prescriptions.Results(1)A total of 93 articles were included,including 117 acupuncture prescriptions and 172 acupoints,with a total frequency of 1 199 times of acupoints.(2)The top 10 acupoints were Fengchi(GB20),Zusanli(ST36),Hegu(LI4),Baihui(DU20),Sanyinjiao(SP6),Taichong(LR3),Quchi(LI11),Yanglingquan(GB34),Wangu(GB12),and Tianzhu(BL10).(3)The top five meridians used frequently were gallbladder meridian of foot shaoyang,governor vessel(GV),stomach meridian of foot yangming,large intestine meridian of hand yangming and bladder meridian of foot taiyang.(4)The selection of acupoints is mainly based on the head,face,neck and lower limbs.(5)The highest frequency of the use of specific points is the intersection point.(6)The high-frequency acupoints for acupuncture treatment of cerebellar ataxia are Fengchi-Wangu,Fengchi-Tianzhu and Fengchi-Tianzhu-Wangu.The top 31 high-frequency acupoints(frequency＞10 times)can be divided into nine effective clusters.Conclusion Acupuncture treatment for cerebellar ataxia has formed a compatibility rule with the main principle of"regulating the mind and constraining the bones,extinguishing wind and stopping the movement",with the far and near acupoints as the main body,and attaches importance to the application of yang meridians with multiple qi and blood,presenting the basic acupoint prescription with Fengchi-Wanggu-Tianzhu as the core.

Tinnitus is a clinically refractory disease with a high incidence.LAI's Tongyuan acupuncture method believes that tinnitus is nothing more than the two ends of deficiency and excess.The deficiency is closely related to original spirit,and the excess is related to the pathological factors such as externally-contracted six pathogenic factors,phlegm-damp and blood stasis,and qi stagnation and yang constraint.The Tongyuan acupuncture method is based on original spirit,takes the two vessels of conception vessel(CV)and governor vessel(GV)as the general outline,takes the regulation of yin and yang as the main method,pays attention to the combination of local and overall,and emphasizes the application of tonification and purgation,and has the clinical effect of reinforcing healthy qi and dispelling pathogen,cultivating the vital essence.In clinical application,the method of'unblocking governor vessel and nourishing spirit'is used to play the role of heart and brain nourishing spirit and warming and supporting yang qi.The method of'conducting qi back to its source'has the effect of cultivating the vital essence and regulating qi movement.The treatments should be cooperated according to the syndromes,so that the pathogens can be expelled and healthy qi can be settled.Qi and blood have origins of generation and transformation and normally nourishing in the ear,so as to effectively alleviate the patient's tinnitus symptoms.This paper summarizes and analyzes Professor LAI Xin-Sheng's Experience in the diagnosis and treatment of tinnitus by Tongyuan acupuncture method,and provides a new acupuncture treatment plan for clinical application.

Objective To develop a low-oxygen mixed gas generator to make up for the deficiencies of low-pressure chambers and load-resistant hypoxia trainers during pilot hypoxia tolerance testing.Methods The device prepared the low-oxygen gas with the principle of gas separation,which was composed of a Sunsource OLF1100D-220AF air compressor,a SMC IDG75SAM4-03 filter,a buffer tank,an AIR Products PA3010 integrated assembly,a control box,sensors and regulators.The sensors included the pressure sensor,flow sensor,concentration sensor and dew point temperature sensor,and the control box consisted of a main control board,a power supply module,a transmission module,a communication module,a display and a housing.The embedded control software of the device was developed with KEIL 5 and C++.Results The device developed prepared the low-oxygen gas with the volume fraction being 4％to 18％and the maximum error of volume fraction being 0.05％,and the main components of the prepared gas met the technical requirements of medical oxygen as stipulated in GB 8982-2009 Oxygen supplies for medicine and aircraft breathing.Conclusion The low-oxygen gas prepared by the device has its volume fraction precisely controlled and can be used for hypoxia tolerance testing and acclimation training for pilots.[Chinese Medical Equipment Journal,2024,45(7):24-28]

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 titer stability of the harvest solution of severe acute respiratory syndrome coronavirus2(SARS-CoV-2)at 2 ～ 8 ℃ and the inactivation effect of β-propiolactone inactivator on the virus.Methods Three batches of SARS-CoV-2 harvest solution(batch numbers:202111001,202111002 and 202111003)were stored at 2 ～ 8 ℃ for 12 d and sampled every 3 d(0,3,6,9 and 12 d)for detection of the titers by Karber method;Three batches of virus harvest solution equilibrated overnight at 2 ～ 8 ℃ were inactivated by adding β-propiolactone at a volume fraction of 1∶4 000 and detected for the titers at different inactivation time points(0,0.5,1,1.5,2,3,4,8,16 and 24 h),of which samples inactivated for 8,16 and 24 h were taken for inactivation verification,and samples inactivated for 24 h were observed by transmission electron microscope.Results The titers of SARS-CoV-2 decreased with the prolongation of storage time at 2 ～8 ℃,which showed no obvious decrease during 0 ～ 3 d,while decreased from the initial 7.75,6 and 7.5 lgCCID_(50)/mL to5.75,4.625 and 6.25 lgCCID_(50)/mL on day 12,indicating that the virus activity showed a gradual decrease trend at 2 ～8 ℃；With the inactivation time,the virus titer decreased continuously and could not be detected after inactivation for 3 h.Transmission electron microscope observation showed that the inactivated virus particles were intact and the spike protein was evenly distributed.Conclusion The virulence of SARS-CoV-2 stored at 2 ～ 8 ℃ was unstable,so the subsequent inactivation and purification process should be carried out as soon as possible;The titer of virus could not be detected after3 h of inactivation,which provided a reference for the determination of the inactivation process.