Antimicrobial Resistance of Aeromonas spp.and Vibrio spp.Isolated from Fresh Pangasius Fish in Cambodia

The study was conducted to identify Aeromonas spp.and Vibrio spp.from fresh Pangasius fish(n=153)in Cambodia and test their antimicrobial susceptibility to antibiotics.The samples were collected from different wet markets of Phnom Penh city and Kampong Thom,and Siem Reap provinces.The bacteria were isolated by using selective medium and their AMR(Antimicrobial Resistance)profile was tested by API 20E technique,respectively.Susceptibility profile was determined for seven antibiotics commonly used.The Vibrio spp.(34.64%,n=53)was found to be higher than Aeromonas spp.(24.83%,n=38).Four Vibrio and four Aeromonas species were identified where V.parahaemolyticus(57%,n=30)was the highest,followed by V.cholerae(38%,n=20),V.fluvialis(3.8%,n=2)and V.aglinolyticus(1.9%,n=1),whereas A.hydrophila(47%,n=18)was the highest,followed by A.hydrophila/caviae(45%,n=17),A.sobria(5%,n=2),A.caviae(2.6%,n=1).All the species presented high multi-resistance to the tested antibiotics.The antibiotic susceptibility profile to ampicillin(74%-100%),ciprofloxacin(7%-100%),sulfamethoxazole/trimethoprim(14%-100%),florfenicol(14%-100%),oxytetracycline(7%-100%),erythromycin(10%-100%)and colistin sulphate(33%-100%)was revealed resistance level in Aeromonas spp.whereas few species of Vibrio spp.resistant to ampicillin(43%-100%),ciprofloxacin(14%-100%),sulfamethoxazole/trimethoprim(14%-100%),florfenicol(14%-100%),oxytetracycline(20%-100%),erythromycin(29%-100%),colistin sulphate(33%-100%)were also identified.The results revealed these Aeromonas spp.and Vibrio spp.are potentially reservoirs of antibiotic resistance genes.MDR(Multidrug Resistance)was widespread among the samples isolated.That is a high-risk source of contamination since those pathogens and antimicrobials are often used.Our findings highlight that the aquatic environment and fresh Pangasius fish act as reservoirs of AMR Aeromonas spp.and Vibrio spp.which underline the need for a judicious use of antimicrobials and timely surveillance of AMR in aquaculture.Overall,the findings of our study indicated the presence of A.hydrophila,A.hydrophila/caviae,A.caviae,A.sobria,V.parahaemolyticus,V.cholerae,V.alginolyticus and V.fluvialis and high MDR.This result will allow us to identify the potential risk over circulating isolates in animal health and public health and the spread through the food chain offering supports for appropriate sanitary actions.

基于改进YOLOv3-SPP算法的道路车辆检测

针对在城市道路场景下视觉检测车辆时,车辆密集和远处车辆呈现小尺度,导致出现检测精度低或者漏检的问题,提出了一种基于改进的YOLOv3-SPP算法,对激活函数进行优化,以DIOU-NMS Loss作为边界框损失函数,增强网络的表达能力。为提高所提算法对小目标和遮挡目标的特征提取能力,引入空洞卷积模块,增大目标的感受野。实验结果表明,所提算法在检测车辆目标时m AP提高了1.79%,也有效减少了在检测紧密车辆目标时出现的漏检现象。

FOSB、SPP1基因表达对经肝动脉介入化疗栓塞术治疗的中晚期肝癌生存期预测价值

目的探讨骨肉瘤原癌基凶同源物B(FOSB)、分泌性磷蛋白1(SPP 1)基因表达对经肝动脉介入化疗栓塞术治疗的中晚期肝癌患者术后生存期的预测价值。方法回顾性分析2016年1月—2017年10月在西安医学院第一附属医院进行诊治的中晚期肝癌患者115例作为研究对象,根据FOSB、SPP 1基因表达水平分为FOSB高表达组(n=52)、FOSB低表达组(n=63)及SPP 1高表达组(n=89)、SPP 1低表达组(n=26)。同时选取115例健康体检者为健康对照组。分析FOSB、SPP 1表达与中晚期肝癌患者临床病理特征的关系。对纳入研究的患者进行为期60个月的随访,Logistics风险回归模型分析影响患者生存期的危险因素。Kaplan-Meier生存曲线分析FOSB、SPP 1表达水平与患者生存预后的关系。结果肝癌患者外周血单个核细胞中FOSB mRNA表达水平明显低于健康对照组,SPP 1 mRNA表达水平明显高于健康对照组,差异具有统计学意义(P<0.05)。FOSB、SPP 1表达在中晚期肝癌患者肿瘤大小、Child-Pugh分级、淋巴转移、BCLC分期方面比较差异具有统计学意义(P<0.05)。单因素分析结果显示,存活组和死亡组在肿瘤大小、Child-Pugh分级、淋巴转移、BCLC分期、FOSB、SPP 1表达方面比较,差异均具有统计学意义(P<0.05)。肿瘤大小、Child-Pugh分级、淋巴转移、BCLC分期、FOSB低表达、SPP 1高表达均为中晚期肝癌患者生存期的独立危险因素(P<0.05)。随访时间60个月,患者生存率为17.39%(20/115),FOSB高表达组中位生存时间为39.7个月,明显高于FOSB低表达组的19.3个月(P<0.05);SPP 1低表达组中位生存时间为40个月,明显高于SPP 1高表达组的18个月(P<0.05)。结论FOSB在中晚期肝癌患者中表达明显下调,SPP 1表达上调,其对预测中晚期肝癌患者肝动脉介入化疗栓塞术治疗生存期具有一定的价值。FOSB、SPP 1有望成为评估介入术治疗患者预后的潜在指标,可协同肿瘤大小、Child-Pugh分级、淋巴转移、BCLC分期等临床指标预测或评估肝癌患者术后生存情况。

海洋菌株Aeromonas sp.YS-54来源几丁质酶的制备与性质研究

为实现甲壳类原料的高效降解与N-乙酰氨基寡糖的绿色制备,本研究以青岛近海土壤中筛选的菌株YS-54为材料,使用60%硫酸铵沉淀、Sephadex G-100凝胶过滤层析制备几丁质酶;对几丁质酶的最适温度、最适pH、底物偏好性等性质进行表征;使用质谱技术确认了酶解产物的聚合度。结果表明,菌株YS-54为Aeromonas属,该菌株来源几丁质酶比活力为23.44 U/mg,分子量为63与75 kDa。几丁质酶在40℃和pH为5.0条件下具有良好的稳定性,Ba^(2+)、Co^(2+)、Mg^(2+)与TritonX-100显著促进了几丁质酶活力(P<0.05),而Fe^(3+)、Cu^(2+)、SDS对酶活力起抑制作用。几丁质酶对α-几丁质的比活力为7.99 U/mg,为水解胶体几丁质比活力的34.09%。几丁质酶对胶体几丁质与α-几丁质的酶解产物聚合度分别为1~4与1~3。Aeromonas sp.YS-54来源几丁质酶在较宽的温度与pH范围内保持稳定,同时对α-几丁质具有良好的水解能力,可为甲壳类废弃物的高效综合利用提供技术支持。

Model prediction of inactivation of Aeromonas salmonicida grown on poultry in situ by intense pulsed light

The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of inactivation.In this work,chicken meat and skin inoculated with meat-borne A.salmonicida isolates were subjected to IPL treatments under different conditions.The results showed that IPL had obvious bactericidal effect in the chicken skin and thickness groups when the treatment voltage and time were 7 V combined with 5 s.In addition,the lethality curves of A.salmonicida were fitted under IPL conditions of 3.5-7.5 V.The comparison of statistical parameters revealed that the Weibull model could best fit the mortality curves and could accurately predict the mortality dynamic of A.salmonicida grown on chicken skin.And further a secondary model between the scale factor b and the treatment voltage in Weibull model was established using linear equations,which determined that the secondary model could accurately predict the inactivation of A.salmonicida.This study provides a theoretical basis for future prediction models of Aeromonas,and also provides new ideas for sterilization approaches of meat-borne Aeromonas.

SPP1和PD-L1在子宫内膜癌组织中的表达及其预后价值

目的:分析分泌型磷蛋白1(secreted phosphoprotein 1,SPP1)和程序性死亡蛋白配体1(programmed cell death-ligand 1,PD-L1)在子宫内膜癌(endometrial carcinoma,EC)组织中的表达水平及与预后的关系。方法:通过免疫组织化学方法分析SPP1和PD-L1在84例EC组织和61例正常子宫内膜组织中的表达情况,分析SPP1和PD-L1表达与临床病理特征及预后的关系,利用UALCAN分析工具(https://ualcan.path.uab.edu/)分析癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中EC组织SPP1和PD-L1 mRNA的表达及与预后的关系。结果:EC组织SPP1阳性表达率高于正常子宫内膜组织(71.43%vs 36.07%,P=0.001),PD-L1阳性表达率低于正常子宫内膜组织(25.00%vs 42.62%,P=0.025);EC组织中,SPP1阳性表达率与组织学分级相关(P<0.05),PD-L1阳性表达率与淋巴结转移相关(P<0.05),SPP1与PD-L1表达呈正相关(列联系数r=0.237,P=0.026);EC组织中,不同SPP1和PD-L1表达患者总生存期无差异(均P>0.05)。TCGA数据库中生物信息学分析显示EC中SPP1 mRNA表达水平显著高于正常子宫内膜组织(P<0.01),PD-L1 mRNA表达水平与正常子宫内膜组织比较,差异无统计学意义(P=0.057);EC组织SPP1 mRNA和PD-L1 mRNA表达水平呈正相关(r=0.350,P<0.05);不同SPP1和PD-L1表达水平患者总生存期无差异(均P>0.05)。结论:SPP1在EC组织中的表达与PD-L1呈正相关,可能共同参与EC免疫微环境调控,SPP1和PD-L1均不是EC独立预后因子。

Genetic Diversity of Jute Mallow (Corchorus spp.) Accessions Based on ISSR Markers

Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported. In the present study, inter sequence simple repeats (ISSR) molecular markers were employed to assess genetic diversity and relationships of 83 accessions of Jute mallow from different parts of Africa and Asia conserved at the World Vegetable Center East and Southern Africa. A total of 89 bands were amplified by 8 ISSR primers. Number of polymorphic bands per primer ranged from 2 to 6 with an average of 2.75 bands per primer. Polymorphic information content (PIC) values ranged from 0.390 to 0.760 with average of 0.53. Average Nei’s gene diversity (h) and Shannon’s information index (I) were 0.335 and 0.494 respectively. The highest pairwise genetic distance was 0.431 observed in a population from East Africa accessions. PC1 and PC2 axis explained 21.69% and 11.66% of the total variation respectively. UPGMA cluster analysis grouped the accessions into six main clusters at genetic similarity coefficient of 0.53 as standard value for classification. These results have important implications for jute mallow breeding and conservation.

Isolation,identification,and virulence gene analysis of pathogenic Aeromonas dhakensis in Macrobrachium rosenbergii and histopathological observation

To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.

Prevalence and Antibiotic Resistance of Urinary Tract Pathogens, with Molecular Identification of Klebsiella pneumoniae, Klebsiella oxytoca, and Acinetobacter spp., Using Multiplex Real-Time PCR

Urinary tract infections (UTIs) caused by uropathogens are a significant public health problem, and their treatment primarily relies on antibiotic therapy. However, the increasing global development of antibiotic resistance necessitates updating diagnostic techniques to ensure higher sensitivity and specificity, especially with advancements in science and medicine. This study aimed to evaluate the prevalence of UTIs and antibiotic resistance profiles through urine culture, as well as to identify Klebsiella pneumoniae, Klebsiella oxytoca, and Acinetobacter spp. in urine samples using a molecular approach with multiplex real-time PCR. From May 3 to July 25, 2023, at the Pietro Annigoni Biomolecular Research Center (CERBA) and Saint Camille Hospital of Ouagadougou (HOSCO), 209 urine samples collected from patients with suspected UTIs were analyzed using both urine culture and multiplex real-time PCR. Among the 209 patients, 52.15% were male and 47.85% female, with an average age of 46.87 ± 21.33 years. Urine cultures revealed an overall UTI prevalence of 23.44%, with a prevalence of 8.13% in men versus 15.31% in women (P = 0.023). The bacterial prevalence rates were as follows: Escherichia coli (12.92%), Klebsiella spp. (7.18%), Enterobacter cloacae (1.44%), Staphylococcus aureus (0.96%), and other bacteria. Klebsiella spp. demonstrated 100% resistance to Amoxicillin and Amoxicillin/Clavulanic Acid, while Escherichia coli showed 96.2% and 65.4% resistance to Amoxicillin and Amoxicillin/Clavulanic Acid, respectively. PCR analysis of the target bacteria revealed mono-infection prevalence rates of Klebsiella pneumoniae (10.39%), Klebsiella oxytoca (7.79%), and Acinetobacter spp. (7.79%), along with a co-infection prevalence rate of Klebsiella pneumoniae/Acinetobacter spp. (1.30%). This study demonstrated that PCR, with its high sensitivity and specificity, could effectively distinguish Klebsiella pneumoniae from Klebsiella oxytoca and detect Acinetobacter spp. in less than 24 hours—something urine culture alone could not achieve. The relative ease of automating urine PCR testing, combined with its diagnostic accuracy and rapid turnaround time, makes it a valuable addition to modern medical practice for the laboratory diagnosis of UTIs.

Effect of dissolved organic nitrogen on the bloom of Prorocentrum donghaiense and Karenia spp. in the East China Sea coastal waters

Understan ding the mechanism of harmful algal bloom formation is vital for effectively preventing algal bloom outbreaks in coastal environments.Karenia spp.blooms in the East China Sea show a significant correlation with nutrient regimes.However,the impact of key components of nutrients,especially dissolved organic nitrogen(DON),on the blooms of Karenia spp.is not clear.Quantitative research is still lacking.In this study,the cruise observations,field mesocosm-flask culture experiments,and a multinitrogen-tri-phytoplankton-detritus model(NTPD) are combined to reveal the quantitative influence of nutrient regimes on the shift of Prorocentrum donghaiense and Karenia spp.in the East China Sea.It has a synchronism rhythm of diatom-P.donghaienseKarenia spp.-diatom loop in the field culture experiment,which is consistent with the results of the cruise observation.The results showed that the processes of terrigenous DON(TeDON) and dissolved inorganic nitrogen(DIN:NO_(3)^(-)-N,NH_(4)^(+)-N) absorption promoted P.donghaiense to become the dominant algae in the community;whereas the processes of DON from P.donghaiense absorption promoted Karenia spp.to become the dominant algae in ambient DIN exhaustion.In addition,the three-dimensional fluorescence components of humus C,tyrosine and fulvic acid can indicate the processes of growth and extinction of P.donghaiense and Karenia spp.,respectively.This study infers that P.donghaiense and Karenia spp.regime shift mechanism associated with the nutrient regime in coastal waters,which provides a scientific basis for the environmental management of coastal eco system health.

Strawberry (Fragaria spp.): Cultivation, Production, Consumption, and Marketing in Cameroon

Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas.

Cloning and Bioinformatics Analysis of hcp Gene in Aeromonas hydrophila

[Objectives]To explore the function of hcp gene in Aeromonas hydrophila.[Methods]A pair of specific primers was designed referring to the hcp gene sequence of A.hydrophila.The hcp gene was amplified by PCR,and performed bioinformatics analysis.[Results]The hcp gene had a total length of 1650 bp and encoded 549 amino acids.The theoretical molecular weight of the protein predicted was about 59476.44 kDa.After predicting the N-terminal signal peptide structure of the amino acid sequence,neither obvious signal peptide cleavage site nor signal peptide was found,and the protein had no transmembrane region.The amino acid sequence had a N-glycosylation site,4 protein kinase C phosphorylation sites,7 casein kinase II phosphorylation sites,9 N-myristoylation sites,4 isoprene binding sites,10 microbody C-terminal target signal sites,and an ATP/GTP binding site motif A(P-ring).The amino acid sequence of hcp gene of A.hydrophila was performed homology analysis with other Aeromonas strains,and it showed higher homology with A.veronii.In the secondary structure,theα-helix,β-sheet,random coil and extended strand accounted for 45.36%,6.01%,37.52%and 11.11%,respectively.The tertiary structure model consisted of 18α-helix and 22β-sheet.Analysis of protein-protein network interaction demonstrated that the proteins interacting with Hcp protein were AHA_3407,nrfA,nirB-1,nirB-2 and AHA_1112.[Conclusions]Through the bioinformatics prediction results,the basic information of hcp gene of A.hydrophila is preliminarily understood,and the possible function of this protein is predicted,in order to provide guidance for subsequent vaccine research.

Botulinum toxin type A-targeted SPP1 contributes to neuropathic pain by the activation of microglia pyroptosis

BACKGROUND Neuropathic pain(NP)is the primary symptom of various neurological condi-tions.Patients with NP often experience mood disorders,particularly depression and anxiety,that can severely affect their normal lives.Microglial cells are as-sociated with NP.Excessive inflammatory responses,especially the secretion of large amounts of pro-inflammatory cytokines,ultimately lead to neuroinflam-mation.Microglial pyroptosis is a newly discovered form of inflammatory cell death associated with immune responses and inflammation-related diseases of the central nervous system.METHODS Two models,an in vitro lipopolysaccharide(LPS)-stimulated microglial cell model and a selective nerve injury model using BTX-A and SPP1 knockdown treatments,were used.Key proteins in the pyroptosis signaling pathway,NLRP3-GSDMD,were assessed using western blotting,real-time quantitative polymerase chain reaction,and immunofluorescence.Inflammatory factors[interleukin(IL)-6,IL-1β,and tumor necrosis factor(TNF)-α]were assessed using enzyme-linked immuno-sorbent assay.We also evaluated microglial cell proliferation and apoptosis.Furthermore,we measured pain sensation by assessing the delayed hind paw withdrawal latency using thermal stimulation.RESULTS The expression levels of ACS and GSDMD-N and the mRNA expression of TNF-α,IL-6,and IL-1βwere enhanced in LPS-treated microglia.Furthermore,SPP1 expression was also induced in LPS-treated microglia.Notably,BTX-A inhibited SPP1 mRNA and protein expression in the LPS-treated microglia.Additionally,depletion of SPP1 or BTX-A inhibited cell viability and induced apoptosis in LPS-treated microglia,whereas co-treatment with BTX-A enhanced the effect of SPP1 short hairpin(sh)RNA in LPS-treated microglia.Finally,SPP1 depletion or BTX-A treatment reduced the levels of GSDMD-N,NLPRP3,and ASC and suppressed the production of inflammatory factors.CONCLUSION Notably,BTX-A therapy and SPP1 shRNA enhance microglial proliferation and apoptosis and inhibit microglial death.It improves pain perception and inhibits microglial activation in rats with selective nerve pain.

Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso

Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.

基于SPPs的二维多凹槽结构MIM波导透射特性的研究

不规则结构对波导的传播特性有着很大的影响,但对于MIM(Metal-Insulator-Metal,金属-介质-金属型)波导双边矩形槽并添加多凹槽结构对传播特性的影响方面的研究尚少。在研究内嵌凹槽位置对MIM波导透射特性影响的基础上,提出了在双矩形波导模型基础的内部添加多凹槽结构来影响波导的透射特性,并对波长与透射的关系及不同凹槽位置、不同凹槽数目的电场模图进行了对比分析。在凹槽位置改变时,Fano共振峰位置发生了移动,在小波长区域共振峰的数目也有所改变。随着上凹槽位置的增大,最大透射峰位置发生了蓝移,透射强度也有一定的增强;增加凹槽对数,得到波长与透射特性的关系曲线发生了改变,随着凹槽对数的增加,Fano共振峰的位置发生了一定的红移,且在小波长600~1 000 nm区域,Fano共振峰数目及透射峰值均发生了变化。这些研究结果可为预测金属缝隙波导制备过程中小尺度、多凹槽局部缺陷结构对其传播特性的影响提供理论依据。

差分码偏差产品对BDS-3多频SPP影响分析

为分析不同差分码偏差(differential code bias,DCB)产品对BDS-3多频伪距单点定位(single point positioning,SPP)的影响,基于IGS跟踪站实测数据,对比分析CAS产品、DLR产品、GBM产品解算B1C/B2a、B1I/B3I、B1C/B2a/B3I、B1I/B2a/B3I伪距单点定位精度的影响。试验结果表明:采用CAS产品解算BDS-3双频和三频伪距单点定位精度较优;采用DLR产品解算B1I/B3I和B1I/B2a/B3I伪距单点定位精度较优,但低于CAS产品;采用DLR产品和GBM产品解算B1C/B2a和B1C/B2a/B3I伪距单点定位精度较差,E、N、U 3个方向精度均低于7 m;无论采用哪种产品,三频伪距单点定位精度均优于双频伪距单点定位精度,且提升量较优。

SPP1、OLR1在宫颈癌的表达及临床意义

观察SPP1(分泌型磷酸蛋白1)、OLR1(氧化低密度脂蛋白受体1)在正常宫颈及宫颈癌中的表达情况,探讨二者与宫颈癌相关临床病理资料及预后的关系。方法 选取2021年01月至2023年01月就诊于包头市肿瘤医院的48例宫颈癌患者为病例组,获取同一时间就诊于该院的48例正常宫颈组织为对照组。应用免疫组化法检测SPP1、OLR1在上述两组的表达情况,初步探讨SPP1和OLR1与宫颈癌患者的关系及二者之间的相关性;采用生物信息学分析对比宫颈癌及正常宫颈中SPP1、OLR1的表达,并分析其与宫颈癌患者生存预后的关系。结果 癌组织中SPP1、OLR1阳性表达率高于正常组织(P<0.05);SPP1的表达与癌组织淋巴结转移、分化程度及FIGO具有相关性(P<0.05);OLR1的表达与癌组织淋巴结转移和分化程度具有相关性(P<0.05);在癌组织中,SPP1和OLR1的表达呈正相关(r=0.423,P=0.007)。与SPP1低表达相比,高表达患者的生存率更低(P<0.05);宫颈癌患者的预后不良与SPP1、OLR1的T分期、N分期相关(P<0.05)。结论 宫颈癌组织的发生发展可能与SPP1、OLR1密不可分,检测这两种蛋白对宫颈癌的发生、发展及预后有一定的帮助。

罗氏沼虾(Macrobrachium rosenbergii)致病性豚鼠气单胞菌(Aeromonas caviae)的分离鉴定及其特性分析

近年来细菌性疾病因病原菌种类繁多、覆盖区域广而影响了其养殖业的健康发展,造成较大的经济损失。从体表具有黑斑、肢体残损症状的罗氏沼虾(Macrobrachium rosenbergii)肝胰腺组织中分离得到1株病原菌,通过形态学观察、生理生化特性鉴定、16S rRNA序列和特定毒力基因检测鉴定,以及人工回归感染试验和药敏试验分析其致病性和耐药性。结果表明,该菌为豚鼠气单胞菌(Aeromonas caviae),含有aer、lip、gcat、ser和OMPA I等毒力基因;药敏试验显示其对头孢曲松、氯霉素等7种抗生素高度敏感,对恩诺沙星、阿米卡星及复方新诺明3种抗生素中度敏感,对四环素、环丙沙星等10种抗生素具有耐药性;人工回归感染实验表明该菌具有较高的致病性,对罗氏沼虾的半致死浓度为6.54×10~5 CFU/mL。豚鼠气单胞菌作为水产养殖中的条件性致病菌,研究结果揭示了该菌株的部分生物学特性,有利于丰富豚鼠气单胞菌属的基础数据,同时也为罗氏沼虾养殖过程中的病害防控提供了一定参考依据。

智能手机BDS-3/GPS数据质量及SPP性能分析

使用可观测到BDS-3 B1I/B1C/B2a频率和GPS L1/L5频率的智能手机Xiaomi 11(青春版)作为研究对象,分别进行静态实验和不同场地的动态实验,分析手机输出的三频BDS和双频GPS原始观测数据质量及单频SPP性能。实验结果表明,智能手机的GNSS天线成本低致使其信号质量不佳,其中GPS L1频率和BDS B1C频率抗干扰性较强:BDS B1C频率定位结果在静态和动态实验中均较为稳定;GPS L1频率定位结果在动态实验中优于GPS L5频率,在静态实验中略差于GPS L5频率。

嗜水气单胞菌(Aeromonas hydrophila)引起斑马鱼肠道生理损伤和肠道菌群失调

研究分析了嗜水气单胞菌(Aeromonas hydrophila)感染斑马鱼后肠道生理健康和肠道微生物的变化。以斑马鱼为研究对象,刮伤皮下真皮,使用10^(5)CFU/mL浓度的嗜水气单胞菌暴露6 h后转入清水,分别在暴露前、暴露后6 h、12 h、24 h取样。使用鱼特异性酶联免疫吸附试验(ELISA)试剂盒,检测肠道中紧密连接蛋白ZO-2(TJP2)含量和乙氧基异戊二烯-O-脱乙基酶(EROD)酶活性,结果表明,嗜水气单胞菌暴露引起了斑马鱼肠道生理损伤,表现为肠道TJP2含量、EROD酶活性在暴露后显著下调。采用16S rRNA高通量测序检测肠道微生物及其菌群结构变化,嗜水气单胞菌暴露斑马鱼后致病菌不动杆菌属(Acinetobacter)明显增加,OTUs数量明显下降,Alpha多样性降低,结果说明嗜水气单胞菌引起了斑马鱼肠道菌群失调。肠道中微生物的多样性与改善肠道上皮和黏膜屏障功能紧密相关,该研究对从肠道健康的角度评价嗜水气单胞菌毒性,探索嗜水气单胞菌的致病机制具有重要意义。