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Phenotypic and Genotypic Characterization of Extended Spectrum β-Lactamase Klebsiella pneumoniae and Fluorescent Pseudomonas spp. Strains from Market Garden Products and Their Watering Water in Benin (West Africa)
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作者 Wassiyath Moussé Pacôme A. Noumavo +4 位作者 Nicodème W. Chabi Haziz Sina Majoie G. Tohoyessou Théodora A. Ahoyo Lamine Baba-Moussa 《Food and Nutrition Sciences》 2016年第3期192-204,共13页
Market garden products can carry several types of microorganisms, and their consumption is the source of many cases of food poisoning. This work aimed to improve food safety in Benin. In characterizing strains of K. p... Market garden products can carry several types of microorganisms, and their consumption is the source of many cases of food poisoning. This work aimed to improve food safety in Benin. In characterizing strains of K. pneumoniae and fluorescent Pseudomonas spp. at the biochemical and molecular level, the target was to identify contaminated watering water and garden products sold during Cotonou in both the dry and rainy seasons. A total of 164 samples of market garden products and 22 samples of watering water were investigated. The results showed that 5.91% of market garden products and watering water were contaminated by K. pneumoniae and 20.43% by fluorescent Pseudomonas spp. During the dry season, cabbage was most contaminated by fluorescent Pseudomonas spp. (50%). Pool water was more contaminated with K. pneumoniae (17%). All isolated strains were resistant to both amoxicillin and penicillin. All strains of K. pneumoniae and fluorescent Pseudomonas spp. were not resistant to imipenem, and 22% of them produced penicillinase. Among the 49 strains producing penicillinase isolated, 64.29% and 21.43% carried bla<sub>TEM</sub> and bla<sub>SHV</sub> respectively while 14.28% carried bla<sub>CTX-M</sub> genes. In light of the previously-developed results and considering the importance of horticultural products in Beninese food habits, we must improve national awareness of the risk for foodborne illness. 展开更多
关键词 Vegetables Klebsiella pneumoniae Fluorescent pseudomonas spp. Β-LACTAMASES Food Safety
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External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis 被引量:4
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作者 MENASRIA Taha TINE Samir +4 位作者 MAHCENE Djaouida BENAMMAR Leyla MEGRI Rochdi BOUKOUCHA Mourad DEBABZA Manel 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第4期316-320,共5页
A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches (Blattella germanica and Blatta orientalis) collected from households in Tebessa (northeast AIgeria).Thr... A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches (Blattella germanica and Blatta orientalis) collected from households in Tebessa (northeast AIgeria).Three major bacterial groups were cultured (total aerobic, enterobacteria, and staphylococci) from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable (P〈0.001) and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of (2.1×10^5 CFU/insect), whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime. 展开更多
关键词 External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp Isolated from Two Household Cockroaches and pseudomonas spp
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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
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作者 燕普 蔡瑜 曾建挺 《西部医学》 2024年第7期992-997,共6页
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11... 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。 展开更多
关键词 FOSB spp 1 经肝动脉介入化疗栓塞术 中晚期肝癌 生存期 预测价值
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基于改进YOLOv3-SPP算法的道路车辆检测
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作者 王涛 冯浩 +4 位作者 秘蓉新 李林 何振学 傅奕茗 吴姝 《通信学报》 EI CSCD 北大核心 2024年第2期68-78,共11页
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... 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。 展开更多
关键词 车辆检测 YOLOv3-spp算法 激活函数 空洞卷积 深度学习
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Genetic Diversity of Jute Mallow (Corchorus spp.) Accessions Based on ISSR Markers
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作者 Munguatosha Ngomuo Tsvetelina Stoilova +1 位作者 Tileye Feyissa Patrick A. Ndakidemi 《American Journal of Plant Sciences》 CAS 2024年第5期316-328,共13页
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.... 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. 展开更多
关键词 Corchorus spp. Genetic Diversity ISSRS Jute Mallow Leafy Vegetable
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Study on Distribution of Four Pseudomonas Species in Living Environment Using Multiplex PCR
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作者 Sachiyo Hayashi Koji Umezawa +12 位作者 Osamu Tsuzukibashi Akira Fukatsu Mana Fuchigami Chiaki Komine Hiroshi Yamamoto Mio Hagiwara-Hamano Yukiko Iizuka Satoshi Uchibori Masanobu Wakami Hiroshi Murakami Taira Kobayashi Masahiko Fukumoto Takato Nomoto 《Open Journal of Stomatology》 2024年第2期77-86,共10页
Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of ... Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of this pathogen exhaustive monitoring of this pathogen is considered of critical importance to public health organizations. The reliable identification method able to distinguish genetic close Pseudomonas species is needed, because these organisms are difficult to differentiate by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect four Pseudomonas species which are frequently detected from the human oral cavities, and to investigate the distribution of these organisms in the living environment using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the rpoD gene of four Pseudomonas species. Swab samples were collected from fifty washstands, and the distribution of Pseudomonas species was investigated using a conventional PCR at genus level and a multiplex PCR at species level. Results: Multiplex PCR method developed in this study was able to distinguish four Pseudomonas species clearly. The genus Pseudomonas was detected from all samples (100%), whereas P. putida, P, aeruginosa, P. stutzeri and P. fluorescens were detected at 44%, 8%, 4% and 2% in fifty swab samples, respectively. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and works without requiring DNA extraction. It was indicated that washstands were the uninhabitable environment for P. putida, P, aeruginosa, P. stutzeri and P. fluorescens. 展开更多
关键词 Genus pseudomonas Multiplex PCR Living Environment
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Strawberry (Fragaria spp.): Cultivation, Production, Consumption, and Marketing in Cameroon
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作者 Djeuani Astride Carole Moutamal Djem Rose Theophine Derricka +21 位作者 Mbouobda Hermann Désiré Abdoulaye Souaibou Meliga Essimi Célestine Bouopda Nono Joël Anafack Donasson Dioril Messouang Bernard Didier Ndongo III Boris Charlen Kaffo Emmanuel Kamga Fossouo Anselme Xavier Tiki Antoine Marie Kevin Nyimiebolo Bengono Audrey Maguy Manuela Diobe Motassy Adounga Samuel Brice Amama Amama Benjamin Nshanji Jones Panguepko Fendju Christophe Nzie Oussena Nguetrapouna Issofa Mpon Ikoyin Linda NKouéya Christelle Ladone Amang Amang A. Ziem Niemenak Nicolas 《Agricultural Sciences》 2024年第4期449-471,共23页
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 ... 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. 展开更多
关键词 Fragaria spp. Cultivation Technique Attack of Pathogens Annual Production Cameroon
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Thoracic spine infection caused by Pseudomonas fluorescens:A case report and review of literature
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作者 Liang Li Bao-Hua Zhang +2 位作者 Jin-Feng Cao Li-Jin Zhang Ling-Ling Guo 《World Journal of Clinical Cases》 SCIE 2024年第12期2099-2108,共10页
BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous syst... BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous system dysfunction,spinal instability and/or deformity,and cause a huge burden on society and families.Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients.At present,the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus,Streptococcus,Pneumococcus,Escherichia coli,and Klebsiella.There are no reports of spinal infection caused by Pseudomonas fluorescens.CASE SUMMARY We report a 32-year-old female patient with spinal infection.She presented with flank pain,initially thought to be bone metastases or bone tuberculosis,and had a family background of tumors.Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection.Histopathology of the lesion showed inflammation,tissue culture of the lesion was negative several times,and the possible pathogen-Pseudomonas fluorescens was found after gene sequencing of the lesion.The patient recovered completely after a full course of antibiotic treatment.CONCLUSION This report increases the range of pathogens involved in spinal infections,highlights the unique advantages of gene sequencing technology in difficult-todiagnose diseases,and validates conservative treatment with a full course of antibiotics for spinal infections without complications. 展开更多
关键词 Thoracic spine infection pseudomonas fluorescens Spinal infection Case report
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Molecular investigation of exoU and exoY virulence genes in Pseudomonas aeruginosa collected from hospitalized patients in North of Iran:A descriptive-analytical study
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作者 Ahmad Reza Moradi Mehrdad Gholami +2 位作者 Lotfollah Davoodi Negar Hajilou Hamid Reza Goli 《Journal of Acute Disease》 2024年第2期74-80,共7页
Objective:To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa infection.Methods:In this study,100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospit... Objective:To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa infection.Methods:In this study,100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospitalized in educational-therapeutic hospitals and were identified using standard microbiological tests.Then,the antibiotic resistance pattern of the isolates was determined by the disk agar diffusion method.The bacterial DNAs were extracted by the alkaline lysis method.Finally,the presence of exoU and exoY genes was evaluated by the PCR test.Results:In this study,47%,72%,29%,39%,40%,and 44%of the isolates were non-susceptible to piperacillin,aztreonam,ceftazidime,imipenem,tobramycin,and ciprofloxacin,respectively.In addition,95%and 93%of the clinical isolates carried the exoU and exoY genes.Blood and fecal isolates had both virulence genes,while only one wound isolate had neither genes.Meanwhile,all urinary isolates contained the exoY gene and only one isolate lacked the exoU gene.Also,88 isolates simultaneously had both exoU and exoY genes.Conclusions:High prevalence of exoU and exoY genes in this region indicates a significant role of typeⅢsecretion system in pathogenesis of Pseudomonas aeruginosa.The typeⅢsecretion system may be a suitable target to reduce the pathogenicity of this bacterium. 展开更多
关键词 pseudomonas aeruginosa exoU exoY Virulence gene TypeⅢsecretion system PCR
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Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso
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作者 Stéphanie Lynseh Carine Sita Bénao Dabiré Amana Métuor +7 位作者 Abdoul Karim Ouattara Rahimatou Yasmine Wendkouni Tiemtoré Nicolas Ouédraogo Blandine Ouédraogo Rhaina Olivia Badini Lionel Eliada Benoit Bambara Serge Sougué Jacques Simporé 《Open Journal of Applied Sciences》 2024年第4期881-892,共12页
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 site... 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. 展开更多
关键词 MULTIDRUG-RESISTANT CHICKEN OUAGADOUGOU Escherichia coli Salmonella spp. Antibiotic
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基于SPPs的二维多凹槽结构MIM波导透射特性的研究
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作者 胡月 陈春梅 孙文汇 《科技与创新》 2024年第9期40-42,共3页
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... 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。 展开更多
关键词 sppS 异常透射 MIM波导 透射特性
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SPP1、OLR1在宫颈癌的表达及临床意义
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作者 赵一昕 徐耀辉 《中文科技期刊数据库(引文版)医药卫生》 2024年第7期0194-0198,共5页
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... 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。 展开更多
关键词 spp1 OLR1 宫颈癌 免疫组化 生物信息学分析
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荧光假单胞菌Pseudomonas fluorescens RN-88抑菌特性研究
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作者 朱李霞 周蓉蓉 +5 位作者 张赛男 毛洪刚 夏禧龙 李春雨 尹冬敏 任建军 《中国农学通报》 2024年第11期22-27,共6页
本研究旨在利用拮抗菌防治植物病害,为桃的病害生物防治提供更多可行性的方案。以前期筛选获得的一株桃褐腐病拮抗细菌荧光假单胞菌(Pseudomonas fluorescens)RN-88为试验材料,采用杯碟法测定发酵液对桃褐腐菌(Monilinia fructicol)的... 本研究旨在利用拮抗菌防治植物病害,为桃的病害生物防治提供更多可行性的方案。以前期筛选获得的一株桃褐腐病拮抗细菌荧光假单胞菌(Pseudomonas fluorescens)RN-88为试验材料,采用杯碟法测定发酵液对桃褐腐菌(Monilinia fructicol)的抑菌活性,并结合抑菌圈法,研究了该菌在pH、温度、紫外线(UV)等不同环境中的稳定性。实验结果表明,细菌RN-88能显著降低桃褐腐病的发病率,其发酵液对褐腐病菌(M.fructicol)的抑制率可达44.69%。在过滤除菌后,相对于高温灭菌,发酵液中抑菌物质的损失较小。在pH 7.5~9.0的碱性溶液中,发酵液的抑菌活性有较好的稳定性,但在酸性溶液(3.0≤pH≤6.5)中处理后,其抑菌能力减弱。发酵液的抑菌率几乎不受温度和紫外线(UV)的影响。Pseudomonas fluorescens RN-88细菌具有较好的环境稳定性,具有开发成桃褐腐病生物拮抗剂的潜在价值,本研究为荧光假单胞菌作为新型生防菌的应用提供了理论依据,同时为实现桃病害的生物防治提供了更多可行性的方案。 展开更多
关键词 桃褐腐病 生防细菌资源 抑菌活性 环境稳定性 荧光假单胞菌
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酚酸介导下连作茶树根际病原菌Alternaria sp.及其拮抗菌Pseudomonas sp.变化 被引量:2
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作者 李艳春 王义祥 +1 位作者 叶菁 李兆伟 《茶叶科学》 CAS CSCD 北大核心 2023年第6期823-834,共12页
茶树是我国重要的经济作物,然而长期宿根连作铁观音茶园存在土壤微生物群落结构失衡、病害加重等连作障碍问题,探究铁观音茶树连作障碍形成的分子机制对寻求有效的防控技术具有重要意义。采用微生物分离纯化、平板对峙等方法对铁观音茶... 茶树是我国重要的经济作物,然而长期宿根连作铁观音茶园存在土壤微生物群落结构失衡、病害加重等连作障碍问题,探究铁观音茶树连作障碍形成的分子机制对寻求有效的防控技术具有重要意义。采用微生物分离纯化、平板对峙等方法对铁观音茶树根际病原菌及其拮抗菌进行分离、鉴定,并对不同宿根连作年限(0、1、10、20 a)铁观音茶树根际土壤中的病原菌和拮抗菌数量进行定量分析;同时运用高效液相色谱(HPLC)技术分析不同连作年限根际土壤中酚酸含量变化,并模拟土壤中各酚酸配比,研究酚酸类物质对茶树根际病原菌及其拮抗菌的影响。结果显示,从连作20 a患病铁观音茶树根系分离鉴定到1株病原真菌链格孢菌(Alternaria sp.),并从根际土壤中筛选到1株拮抗菌假单胞菌(Pseudomonas sp.)。荧光定量PCR分析发现,与1 a茶园相比,20 a茶园土壤中的链格孢菌绝对含量显著偏高,而假单胞菌含量却显著偏低。连作茶园根际土壤中共检测到对羟基苯甲酸、香草酸、丁香酸、香兰素、阿魏酸5种酚酸类物质,其平均配比为38∶229∶11∶11∶3。连作条件下酚酸类物质并未在土壤中累积,而是随种植年限的延长呈现出先增加后降低的趋势。模拟试验发现,中低浓度(30~120μmol·L^(-1))的混合酚酸能够显著促进链格孢菌菌丝的生长,单一酚酸对羟基苯甲酸、香草酸和丁香酸在低浓度(30μmol·L^(-1)和60μmol·L^(-1))时也能够显著促进链格孢菌菌丝的生长。对羟基苯甲酸对假单胞菌的生长有抑制作用,并且随着浓度的增加抑制作用增强,混合酚酸以及其他单一酚酸对假单胞菌的生长无明显作用。由此可见,铁观音根系分泌物酚酸类物质对根际土壤关键微生物菌群具有不同的生态效应,是引起微生物群落结构失衡、病害增加等连作障碍问题的重要因素。研究结果为进一步揭示铁观音茶树连作障碍机理提供一些理论依据。 展开更多
关键词 茶树 连作障碍 酚酸类物质 链格孢菌 假单胞菌
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锑氧化菌Pseudomonas sp.AO-1的分离鉴定及其对Sb(III)的氧化性能 被引量:1
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作者 隆佩 邓仁健 +5 位作者 杨宇 金贵忠 黄中杰 周新河 王西峰 王闯 《中国环境科学》 EI CAS CSCD 北大核心 2023年第2期904-914,共11页
采用抗性筛选法从锡矿山筛选出一株锑氧化菌,并利用分子生物学技术对其进行鉴定;考察了其氧化Sb()Ⅲ的性能和氧化次生矿物的特征.结果表明:锑氧化菌属于假单胞菌属(Pseudomonas),将其命名为Pseudomonas sp.AO-1(简称:AO-1);影响AO-1氧化... 采用抗性筛选法从锡矿山筛选出一株锑氧化菌,并利用分子生物学技术对其进行鉴定;考察了其氧化Sb()Ⅲ的性能和氧化次生矿物的特征.结果表明:锑氧化菌属于假单胞菌属(Pseudomonas),将其命名为Pseudomonas sp.AO-1(简称:AO-1);影响AO-1氧化Sb(Ⅲ)的因素主要有溶液pH值、溶解氧和铁锰氧化物(单质铁、FeCl_(3)和MnO_(2))等;AO-1在好氧和缺氧条件下均能氧化Sb(Ⅲ),好氧氧化Sb(Ⅲ)的米门常数Km和最大氧化速率Vmax值分别为393.05µmol/L和0.271µmol/(L·min),体现了较强的锑氧化性;AO-1和铁锰氧化物的耦合作用能促进Sb(Ⅲ)的氧化,且铁锰氧化物促进AO-1氧化Sb(Ⅲ)的速率依次为:FeCl_(3)>MnO_(2)>单质铁;AO-1和铁锰氧化物耦合氧化Sb(Ⅲ)生成含Sb(Ⅴ)的次生矿物,次生矿物会加速Sb(Ⅲ)的氧化以及影响锑在环境中的迁移转化.菌株AO-1的锑氧化性能良好,对于锑的生物化学转化和土壤微生物修复的应用有重要意义. 展开更多
关键词 锑氧化菌 pseudomonas sp.AO-1 SB(III) 氧化 铁锰氧化物
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砷氧化菌Pseudomonas sp.AO-1的分离鉴定及其对As(Ⅲ)的氧化性能研究 被引量:2
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作者 杨宇 邓仁健 +3 位作者 隆佩 黄中杰 任伯帜 王政华 《生态环境学报》 CSCD 北大核心 2023年第3期619-626,共8页
随着环境砷污染日趋严重和不断地传播使得人类健康处于高风险之中,修复治理环境中的砷污染刻不容缓。将As(Ⅲ)氧化为As(Ⅴ)是治理砷污染的关键步骤,因此寻找一种经济且绿色的氧化技术成为了研究热点,而微生物氧化As(Ⅲ)被认为是治理砷... 随着环境砷污染日趋严重和不断地传播使得人类健康处于高风险之中,修复治理环境中的砷污染刻不容缓。将As(Ⅲ)氧化为As(Ⅴ)是治理砷污染的关键步骤,因此寻找一种经济且绿色的氧化技术成为了研究热点,而微生物氧化As(Ⅲ)被认为是治理砷污染一种绿色经济可行的方法。从湖南锡矿山矿区含砷的土壤中筛选出一株砷氧化菌,并利用分子生物学技术对其进行了鉴定;研究了其对As(Ⅲ)的抗性,不同As(Ⅲ)浓度下的生长特征曲线,不同pH条件下As(Ⅲ)的氧化性能,生长曲线及其氧化动力学。研究结果表明:该菌属于假单胞菌属(Pseudomonas),将其命名为Pseudomonas sp.AO-1(简称:AO-1),其对As(Ⅲ)的抗性达2000 mg·L^(-1),具有较高的抗性;当As(Ⅲ)质量浓度高于100 mg·L^(-1)时,菌株AO-1的生长受到了明显的抑制,其进入对数增殖期的时间延后,稳定期较短,衰亡期提前;pH对菌株AO-1的生长及As(Ⅲ)氧化率有显著的影响,其最适生长pH为7;当pH为3-8时,菌株AO-1氧化As(Ⅲ)的氧化率随pH的升高先提高后减小,pH为7时As(Ⅲ)氧化率到达最大的72.5%;菌株AO-1好氧化氧化As(Ⅲ)的米门常数Km和最大氧化速率Vmax值分别为274.70μmol·L^(-1)和0.31μmol·(L·min)-1,其Km低于一些已研究的菌株,体现菌株AO-1对As(Ⅲ)具有良好的亲和力,也表明了其具有较好的As(Ⅲ)氧化性能。综上,该研究所筛选的菌株AO-1具有良好的耐砷性和As(Ⅲ)氧化性,在水体及土壤砷污染修复与治理中具有的潜在应用价值。 展开更多
关键词 砷污染 砷氧化菌 pseudomonas sp.AO-1 砷抗性 氧化性能 氧化动力学
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智能手机BDS-3/GPS数据质量及SPP性能分析 被引量:1
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作者 王瑞光 王中元 +2 位作者 胡超 王阳阳 刘冰雨 《大地测量与地球动力学》 CSCD 北大核心 2023年第2期168-172,共5页
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... 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。 展开更多
关键词 Android智能手机 单频spp BDS-3 GPS 数据质量分析
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鸭SPP1基因的生物信息学分析、原核表达及其在鸭胚胎期骨骼肌中表达规律研究 被引量:1
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作者 曹敞 职卓 +6 位作者 蔡瑛婕 李雨笑 张纪桥 张淑雅 刘小林 胡志刚 张建勤 《中国畜牧杂志》 CAS CSCD 北大核心 2023年第7期147-154,共8页
分泌型焦磷酸蛋白1(SPP1)是一种具有多种功能的分泌型酸性糖蛋白,在肌肉发育过程中具有重要的调控作用,但SPP1基因在鸭骨骼肌中的结构和功能尚不明确。本研究选择胚胎期第17天(E17 d)、第21天(E21 d)、第24(E24 d)和第27天(E27 d)北京... 分泌型焦磷酸蛋白1(SPP1)是一种具有多种功能的分泌型酸性糖蛋白,在肌肉发育过程中具有重要的调控作用,但SPP1基因在鸭骨骼肌中的结构和功能尚不明确。本研究选择胚胎期第17天(E17 d)、第21天(E21 d)、第24(E24 d)和第27天(E27 d)北京鸭和汉中麻鸭胸肌及腿肌组织作为实验材料,克隆了SPP1基因的CDS区序列并对该序列进行分析,进一步诱导基因表达,采用SDS-PAGE检测表达蛋白。同时采用qPCR方法分析SPP1基因在胚胎期北京鸭与汉中麻鸭胸肌和腿肌组织中的相对表达。结果表明:SPP1基因开放阅读框大小为915 bp,编码304个氨基酸,是有SP型信号肽的亲水性不稳定蛋白,无跨膜结构,有磷酸化和糖基化位点。qPCR结果表明,北京鸭骨骼肌SPP1的表达量在E27 d达到最高;而汉中麻鸭胸肌SPP1在E17 d的表达量最高,在E21 d的腿肌中表达量最高。在胚胎期北京鸭与汉中麻鸭骨骼肌的比较中,汉中麻鸭胸肌SPP1基因在E17 d时的表达量显著高于北京鸭,而在E27 d则低于北京鸭。北京鸭腿肌SPP1在E17 d和E27 d的表达量均高于汉中麻鸭,而在E21 d和E24 d则均低于汉中麻鸭。本研究揭示了鸭SPP1基因的结构及该基因在北京鸭和汉中麻鸭骨骼肌中的表达规律,为鸭生长发育的调控机制研究提供一定的参考。 展开更多
关键词 spp1 骨骼肌 原核表达 生物信息学分析 表达规律
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基于YOLOv3-SPP的遥感图像目标检测压缩模型 被引量:1
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作者 齐保贵 赵鹏赫 +2 位作者 陈禾 陈亮 龙腾 《信号处理》 CSCD 北大核心 2023年第9期1621-1632,共12页
近年来,卷积神经网络模型已被广泛应用于遥感图像目标检测任务中,但自然场景图像与遥感图像的目标特性存在差异,针对自然场景设计的模型往往难以在遥感图像任务中取得良好的效果。同时,很多遥感图像处理任务需要在星载、机载等资源有限... 近年来,卷积神经网络模型已被广泛应用于遥感图像目标检测任务中,但自然场景图像与遥感图像的目标特性存在差异,针对自然场景设计的模型往往难以在遥感图像任务中取得良好的效果。同时,很多遥感图像处理任务需要在星载、机载等资源有限的平台中进行,难以部署参数量、计算量大的复杂模型。针对以上问题,本文对在自然场景中性能优异的YOLOv3-SPP模型进行适应性改进及参数压缩。首先,对原始的L1范数剪枝算法进行改进,提出基于L1范数和均值差的加权剪枝算法,能够更好地保留重要的通道。其次,对剪枝后的子网集合进行快速评估,选取评估结果最好的子网进行微调。在预训练和微调阶段,本文将SPP模块中的最大池化层替换为softmax加权池化层,着重突出深层网络中权重较大的特征,提高了模型的检测精度。本文在多个公开遥感数据集上进行实验,结果表明改进的YOLOv3-SPP模型在遥感目标检测任务上具有更好的性能,同时本文的剪枝算法可以在相同的参数压缩比例条件下,降低模型的性能损失。 展开更多
关键词 目标检测 YOLOv3-spp 遥感 模型压缩
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城市复杂环境下不同加权模型对动态SPP定位性能影响分析 被引量:2
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作者 付红波 《测绘通报》 CSCD 北大核心 2023年第3期139-143,共5页
城市复杂环境下,由于建筑物的遮挡,卫星定位严重受到非视距信号的影响。测量值随机误差加权模型是卫星定位的关键环节,它能够合理地分配各卫星在解算中所起作用的大小。因此,加权模型常用于缓解非视距信号对卫星定位的影响。本文针对目... 城市复杂环境下,由于建筑物的遮挡,卫星定位严重受到非视距信号的影响。测量值随机误差加权模型是卫星定位的关键环节,它能够合理地分配各卫星在解算中所起作用的大小。因此,加权模型常用于缓解非视距信号对卫星定位的影响。本文针对目前主流的多种加权模型进行了系统总结和阐述,比较和分析了城市复杂环境下不同加权模型对卫星动态单点定位的影响。试验结果表明,各加权模型均能够在一定程度上提高定位精度,其中综合加权模型具有最优的性能表现。 展开更多
关键词 城市复杂环境 非视距信号 加权模型 动态spp
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