Objective This study aimed to investigate the seasonal variation of mosquitoes in Yantai, Shandong Province, and provide a scientific basis for mosquito and mosquito-borne disease control. Methods From March to November for each of the years between 2020 and 2023, adult mosquitoes were collected from different habitats, including parks, hospitals, urban residential areas, rural households and livestock sheds, in 13 counties of Yantai City using a mosquito trap lamp method, among which, female mosquitoes were separated and identified, and the numbers were counted. We used the circular distribution method to analyze the temporal distribution characteristics of mosquito density. Results The γ values obtained for mosquitoes in Yantai from 2020 to 2023, the distribution of mosquitoes in different habitats, and dominant mosquito species in different months showed strong seasonality, with values ranging from 0.7461 to 0.8531(P ＜ 0.05). The peak period of seasonal variation in mosquitoes occurred from June 28thto September 13th, with August 5thbeing identified as the peak day. The peak periods of seasonal variation in mosquitoes in residential areas, parks, hospitals, peasant households, and animals sheds were observed from June 24thto September 14th, June 25thto September 10th, June 22ndto September 12th, July 1stto September 9th, and July 2ndto September 17th, respectively, with corresponding peak days on August 4th,3rd, 2nd, 5th, and 9th, respectively. The peak periods of Culex pipiens pallens, Aedes albopictus, and Anopheles sinensis were from June 26thto September 11th, June 28thto September 17th, and July 12thto September 17th, respectively, with corresponding peak days on August 3rd,7th, and 14th, respectively. Conclusions Our findings in this study revealed that the peak of mosquito activity in Yantai was concentrated in early August, with a peak period extending from June 28thto September 13th, and there were differences between different habitats(with peak periods for rural households and livestock sheds occurring later than those in residential areas, parks, and hospitals). Moreover, with respect to the mosquito species, populations of Cx. pipiens pallens and Ae. albopictus peaked earlier than those of An. sinensis. Based on these findings, we recommend that city-wide mosquito control work should commence in late June, and include appropriate early prevention and control measures for key habitats, such as livestock sheds, and dominant mosquito species, such as Cx. pipiens pallens, to minimize the density of mosquito vectors and the risk of disease transmission.

Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.

Objective: To examine the effects of combined aerobic and resistance exercise on health related physical fitness (HPF) and depressive symptoms among senior high school freshmen, and to examine whether HPF mediates the relationship between exercise intervention and depressive symptoms, so as to provide a scientific basis for the coordinated promotion of mental health and physical fitness in schools. Methods: In March 2022, 190 senior high school freshmen from a secondary school of Suzhou in Anhui Province were selected by the random cluster sampling method and randomly assigned to an intervention group ( n = 99) and a control group ( n =91). The control group maintained routine activities, while the intervention group underwent a 10 week combined aerobic and resistance exercise program, three sessions per week, 40 minutes per session. Height, weight, standing long jump, sit ups, 20 m shuttle run, and sit and reach were measured before and after the intervention. Depressive symptoms were assessed using the Center for Epidemiological Studies Depression Scale (CES-D). Analysis of covariance (ANCOVA), Mann-Whitney U test, and Wilcoxon test were employed to compare outcomes before and after the intervention, and mediation analysis was conducted. Results: After controlling for pre test scores, ANCOVA results showed that compared with the control group, the intervention group demonstrated the following post intervention changes: a lower body mass index of 0.1 kg/m 2 among girls; higher standing long jump (13.2 cm for boys, 7.4 cm for girls), higher sit ups (5.5 reps for boys, 3.7 reps for girls), higher 20 m shuttle run (7.4 times for boys, 5.1 times for girls), and higher sit and reach (3.2 cm for boys, 0.4 cm for girls) ( F =17.88-84.44); and lower CES-D scores (5.5 for boys, 4.0 for girls) ( Z =-2.51, -2.06) (all P <0.05). The indirect effect of HPF in the relationship between combined aerobic and resistance exercise and depressive symptoms was -2.11, supporting a partial mediation effect ( P < 0.01 ). Conclusions Combined aerobic and resistance exercise improves HPF and alleviates depressive symptoms to varying degrees among senior high school freshmen. HPF served as a partial mediator through which exercise intervention reduces depressive symptoms.

AIM To study the chemical constituents from the stems and barks of Maytenus variabilis(Hemsl.)C.Y.Cheng.METHODS The 95％ethanol extract from the stems and barks of M.variabilis was isolated and purified by silica gel,Sephadex LH-20 and semi preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Twenty-three compounds were isolated and identified as β-amyrin(1),3β-acetoxyolean-12-en-11-one(2),ursa-12-ene-11-one-3-ol octocosate(3),friedelin(4),canophyllol(5),pinoresinol(6),medioresinol(7),isolariciresinol(8),dihydrodehydrodiconiferyl alcohol(9),vanillic acid(10),7R,8S-5-methoxydihydrodehydroconiferyl alcohol(11),β-hydroxypropiovanillone(12),triptregeline B(13),triptregeline E(14),(+)-evofolin B(15),2,5-dimethoxybenzoquinone(16),olean-12-ene-3,11-dione(17),β-sitosterol(18),(-)-(7R,7'R,7"S,8S,8'S,8"S)-4',4"-dihydroxy-3,3',3",5-tetramethoxy-7,9',7',9-diepoxy-4,8"-oxy-8,8'-sesquineolignan-7",9"-diol(19),phyllostadimer B(20),rayalinol(21),lyoniresinol(22),dihydrobuddlenol B(23).CONCLUSION Compounds 3,9-11,13-14,16,19-21,23 are isolated from genus Maytenus for the first time,and compounds 2,4-5,7-8,12,15,17,22 are first found from this plant.

OBJECTIVE To formulate an expert consensus on the prevention and control of respiratory infectious diseases in railway stations and trains in China,and to standardize the prevention and control of respiratory infec-tious diseases in railway stations and trains scientifically.METHODS The government authorities organized multi-ple prevention and control experts from transportation,medical care and prevention fields to conduct in-depth re-search through methods such as meetings and on-site investigations,and combined with their practical experi-ence in this field to formulate this expert consensus.RESULTS In-depth studies were conducted on the prevention and control strategies,measures and emergency response system construction of respiratory infectious diseases in railway stations and trains,and this expert consensus was formed.CONCLUSION This expert consensus supple-ments improves the existing prevention and control system for respiratory infectious diseases in railway stations and trains,and provides an important reference basis for the prevention and control of respiratory infectious disea-ses in railway stations and trains.

Sarin(GB)is a typical representative of nerve agents with high toxicity,and very low amount can cause death.GB can cause water and atmospheric environment poisoning,so the detection of GB in water and air is of great significance.In this work,a colorimetric sensor array(CSA)based on GB inhibition of cholinesterase activity was constructed to detect GB with high selectivity.A 4×4 colorimetric array was constructed using acetylcholinesterase(AChE),butyryl cholinesterase(BuChE)and the corresponding substrate acetylthiocholine iodide(S-ACh),butyryl thiocholine iodide(S-BCh),acetylcholine chloride(ACh),butyryl choline chloride(BCh)and 2,6-dichloroindophenol ethyl ester(DCIE).The linear curve of the sensor was Y=131.3×lgC+271.6(R2=0.997),where Y was the array response Euclidean distance,C was the concentration of GB(mg/L),the linear range was 0.03?0.32 mg/L,and the detection limit was 27.6 μg/L.The method could effectively distinguish chemical warfare agents(CWA)such as VX,Soman(GD),mustard gas(HD),Louie reagent(L),and had high anti-interference ability,sensitivity and good repeatability.It was successfully applied to the detection of GB in simulated water and simulated air samples,and the sample recovery rate was 97.2% ?100.9%.This method would be potentially applied to the field rapid detection of nerve agents.

A solid-phase extraction-ultra-performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)method was established for simultaneous determination of 10 kinds of neonicotinoid pesticide residues in aquaculture water.Based on the chemical properties of neonicotinoid pesticides and the matrix characteristics of aquaculture water,suitable temporary storage methods for water samples and appropriate solid-phase extraction columns were selected,and the extraction conditions(including elution solvents and sample loading volumes)were optimized.The method employed acetonitrile and 5 mmol/L ammonium acetate solution(containing 0.1%formic acid)as the mobile phase and an Oasis HLB solid-phase extraction column combined with PSA as a dispersive sorbent for sample purification.The method exhibited good linearity in detection of neonicotinoid in concentration range of 0.2-50 ng/mL(R2>0.99797),with a detection limit of 0.5 ng/L and a quantification limit of 1 ng/L,which were significantly lower than the maximum acceptable method detection limits(9-500 ng/L)for neonicotinoid insecticides in water published by the European Commission.In pond water,rice-fish water,and seawater,the average recoveries of the 10 target analytes were 74.6%-114.1%,with relative standard deviations ranging from 0.3%to 9.6%.Using this method,actual sample tests were conducted on the Pearl River water,Zhaoqing pond water,and Qingyuan rice-fish aquaculture water.The total concentration of five neonicotinoid pesticides in the Pearl River water ranged from 154.8 to 246.6 ng/L,the total concentration of four neonicotinoid pesticides in the Zhaoqing pond water was 95.0-176.1 ng/L,and the total concentration of three neonicotinoid pesticides in the Qingyuan rice-fish aquaculture water was 2.3-11.7 ng/L.This method was simple in operation,highly sensitive,and had strong resistance to interference.It was suitable for detection of trace neonicotinoid pesticides in aquaculture water and could provide technical support for construction of a green aquaculture environment and resolution of international trade disputes.

The electrocatalytic nitrate reduction reaction(NO3RR)presents a sustainable pathway for large-scale ammonia production,yet it faces significant challenges due to proton supply limitations caused by the high energy barrier for water dissociation,which slows ammonia(NH3)generation.Herein,a palladium(Pd)-modified copper-cobalt(CuCo)hollow fiber penetration electrode that enabled H2 injection through its hollow structures,thereby enhancing proton availability for NO3RR was developed.The active Pd component efficiently dissociated H2,facilitating active hydrogen(*H)spillover and speeding up the cascade NO3RR process on Cu and Co sites.As a result,a half-cell energy efficiency of 39.53%and an NH3 Faradaic efficiency(FE)of 97.11%±1.17%at-0.1 V(vs RHE)were achieved,comparable to state-of-the-art systems.Importantly,the H2-assisted approach prevented the oxidation of active Cu and Co phases,demonstrating exceptional stability with less than 5.6%decay in current density(267 mA/cm2)and retention of NH3 FE at 94.8%after over 70 h of electrolysis.These findings offered valuable insights into proton supply pathways and design of NO3RR electrodes.

Foodborne illnesses caused by Salmonella pose significant threats to worldwide public health safety.In this study,a rapid method for screening viable Salmonella in oyster sauce and milk was developed by utilizing an electronic microbial growth analyzer(EMGA).Target food samples were diluted 10-fold with RVS broth and loaded into test tubes.Test tubes were positioned in the EMGA to determine the bacterial growth curves and the time required to reach the maximum growth rate(Tmgr).Using Salmonella typhimurium(S.typhimurium)asan model species,there was linear relationship between the logarithmic value of viable bacterial concentration(lgC)and Tmgr over the range of 5×101-5×106 CFU/mL,with a detection limit of 10 CFU/mL.For oyster sauce,the regression equation was Tmgr(min)=-80.775lg[C/(CFU/mL)]+754.96(R2=0.9907),and the recovery rates of S.typhimurium ranged from 95.2%to 119.8%,with relative standard deviations(RSD)ranging from 3.5%to 16.3%.For milk,the regression equation was Tmgr(min)=-71.922 lg[C/(CFU/mL)]+618.65(R2=0.9985),with recovery rates ranging from 98.4%to 110.6%and RSD ranging from 6.4%to 12.8%.The EMGA method required only one portable instrument,and involving only three manual steps,i.e.,dilution,transfer,and insertion.When S.typhimurium contamination reached 106 CFU/mL,the total time consumption,from the unwrapping of samples to the readout of bacterial concentration,was no more than 7 h.When applied to detection of actual oyster sauce and milk samples,the new method demonstrated strong consistency with plate counting results in positive detection rates.This method was superior to the plate counting method,which was generally considered as a gold standard,in terms of accuracy,precision,simplicity and efficiency,representing a promising alternative for the on-site screening and quantification of viable Salmonella in oyster sauce and milk products.