nuc

NUC
  • 文章类型: Journal Article
    目标:直到最近,聚乙二醇化干扰素-α-2a(PEG-IFNa)治疗是感染丁型肝炎病毒(HDV)患者的唯一治疗选择。用PEG-IFNa治疗有或没有替诺福韦酯富马酸酯(TDF)96周导致44%的患者在治疗结束时的HDVRNA抑制,但不能防止24周内的短期复发。在延长基于PEG-IFNa的丁型肝炎治疗后的病毒学和临床长期效果是未知的。
    方法:在HIDIT-II研究中,患者(包括40%肝硬化)每周接受180μgPEG-IFNa加300mgTDF,每天一次(n=59)或180μgPEG-IFNa每周加安慰剂(n=61),持续96周。患者随访至第356周(治疗结束后5年)。
    结果:直到随访结束,16(13%)患者出现肝脏相关并发症(PEG-IFNa+TDF,n=5vsPEG-IFNa+安慰剂,n=11;p=.179)。在第96周实现HDV抑制与肝细胞癌(p=.04)和肝失代偿(p=.009)的长期风险降低相关。包括与PEG-IFNa再治疗状态无关的并发症,出现严重并发症的患者数量与(3/18)相似,且未使用PEG-IFNa再治疗(16/102,p>.999),但与HDV-RNA抑制的机会较高相关(p=.024,比值比3.9[1.3-12]).
    结论:在对PEG-IFNa治疗有病毒学应答的患者中,肝脏相关临床事件很少发生,发生频率较低。PEG-IFNa治疗应推荐给HDV感染的患者,直到替代疗法可用。对于第一个疗程反应不足的患者,应考虑使用PEG-IFNa进行复治。
    背景:NCT00932971。
    Until recently, pegylated interferon-alfa-2a (PEG-IFNa) therapy was the only treatment option for patients infected with hepatitis D virus (HDV). Treatment with PEG-IFNa with or without tenofovir disoproxil fumarate (TDF) for 96 weeks resulted in HDV RNA suppression in 44% of patients at the end of therapy but did not prevent short-term relapses within 24 weeks. The virological and clinical long-term effects after prolonged PEG-IFNa-based treatment of hepatitis D are unknown.
    In the HIDIT-II study patients (including 40% with liver cirrhosis) received 180 μg PEG-IFNa weekly plus 300 mg TDF once daily (n = 59) or 180 μg PEG-IFNa weekly plus placebo (n = 61) for 96 weeks. Patients were followed until week 356 (5 years after end of therapy).
    Until the end of follow-up, 16 (13%) patients developed liver-related complications (PEG-IFNa + TDF, n = 5 vs PEG-IFNa + placebo, n = 11; p = .179). Achieving HDV suppression at week 96 was associated with decreased long-term risk for the development of hepatocellular carcinoma (p = .04) and hepatic decompensation (p = .009). Including complications irrespective of PEG-IFNa retreatment status, the number of patients developing serious complications was similar with (3/18) and without retreatment with PEG-IFNa (16/102, p > .999) but was associated with a higher chance of HDV-RNA suppression (p = .024, odds ratio 3.9 [1.3-12]).
    Liver-related clinical events were infrequent and occurred less frequently in patients with virological responses to PEG-IFNa treatment. PEG-IFNa treatment should be recommended to HDV-infected patients until alternative therapies become available. Retreatment with PEG-IFNa should be considered for patients with inadequate response to the first course of treatment.
    NCT00932971.
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  • 文章类型: Journal Article
    金黄色葡萄球菌的存在,研究了Ile-Ife不同专业人员的手机上的正常人类菌群,以确定其抗生素敏感性以及抗性和毒力基因的性质。根据他们的职业,从各种用户的手机中无菌收集了一百个拭子样本。擦拭手机的表面,并使用条纹平板法分离在甘露醇盐琼脂平板上显示特征性金黄色的菌落。使用标准微生物学方法进一步鉴定这些分离物。使用Kirby-Bauer的圆盘扩散技术确定分离株的抗生素敏感性。nuc的分子检测,通过聚合酶链反应技术在一些分离物中进行mecA和pvl基因。在这项研究中获得的所有36个分离株对阿莫西林和增强素具有100%的耐药性;这些分离株还显示55.6%,对头孢曲酮的耐药率为44.4%和41.7%,红霉素和氯霉素,分别。基于对苯唑西林的耐药性,耐甲氧西林金黄色葡萄球菌(MRSA)的患病率为11.1%.只有一个金黄色葡萄球菌对质粒分析是阳性的。MecA基因在16个疑似表型MRSA菌株中的四(4)个中被遗传证实,在所有28个被调查的分离株中确认了nuc基因,而研究的菌株中没有pvl基因。手机含有多种抗生素抗性金黄色葡萄球菌,它们是人类重要疾病的原因,并且可能难以用抗生素进行管理,从而构成严重的健康风险。
    The presence of Staphylococcus aureus, a normal human flora on cellphones of different professionals in Ile-Ife was investigated with a view to determining their antibiotic susceptibility profile and nature of resistance and virulence genes. One hundred swab samples were collected aseptically from mobile phones of various users based on their profession. Surfaces of the mobile phones were swabbed and the streak plate method was used to isolate colonies showing characteristic golden yellow on mannitol salt agar plates. These isolates were further identified using standard microbiological methods. The antibiotic susceptibility of the isolates was determined using Kirby-Bauer\'s disk diffusion technique. Molecular detection of nuc, mecA and pvl genes in some isolates was carried out by polymerase chain reaction technique. All the 36 isolates obtained in this study were 100% resistant to amoxicillin and augmentin; the isolates also displayed 55.6%, 44.4% and 41.7% resistance to ceftriazone, erythromycin and chloramphenicol, respectively. Based on resistance to oxacillin, prevalence of methicillin resistant Staphylococcus aureus (MRSA) was 11.1%. Only one S. aureus was positive for plasmid analysis. MecA gene was genetically confirmed in four (4) out of the 16 suspected phenotypic MRSA strains, nuc gene was confirmed in all 28 isolates investigated, while there was no pvl gene in the strains investigated. Mobile phones harbor multiple antibiotics resistant S. aureus, which are responsible for important diseases in humans and could be difficult to manage with antibiotics thereby posing serious health risks.
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  • 文章类型: Journal Article
    金黄色葡萄球菌是已知快速获得抗生素抗性的革兰氏阳性菌,并且对全世界的临床医生构成重大挑战。耐甲氧西林金黄色葡萄球菌(MRSA)感染通常与死亡率增加和治疗时间延长有关。来自不同来源(牲畜,宠物,动物管理员,人类医院)收集并通过表型和基因型方法筛选MRSA的存在。金黄色葡萄球菌在山羊中的发生率较高(42.00%;28.20-56.80%,置信区间[CI]95.00%),其次是牛(13.50%;9.20-18.80%,CI95.00%),人类(12.90%;9.30-17.40%,CI95.00%)和狗(12.90%;8.10-19.20%,CI95.00%)。在狗中观察到MRSA的发生率明显更高(65.00%;40.80-84.60%,CI95.00%),与其他寄主牛相比(48.00%;26.50-64.30%,CI95.00%),人类(35.00%;20.20-52.50%,CI95.00%)和山羊(10.00%;1.20-30.40%,CI95.00%)。通过聚合酶链反应(PCR)进一步筛选所有金黄色葡萄球菌分离株的热稳定核酸酶(nuc基因)。牛的nuc基因的发病率,狗,山羊和人的比例为3.30%(1.30-6.60%,CI95.00%),5.20%(2.30-9.90%,CI95.00%),28.00%(16.20-42.50%,CI95.00%)和9.10%(6.00-13.00%,CI95.00%),分别。对两种PCR引物(mecA-162和mecA-310)的比较评估表明,前者是检测MRSA的更合理选择。总的来说,我们的研究结果表明MRSA可能存在来自犬的人畜共患传播风险.
    Staphylococcus aureus are Gram positive bacteria known to acquire antibiotic resistance rapidly and pose a major challenge to clinicians worldwide. Infections by methicillin resistant Staphylococcus aureus (MRSA) are usually associated with increased mortality and prolonging of treatment. Samples (n = 706) from diverse sources (livestock, pets, animal handlers, human hospital) were collected and screened for the presence of MRSA by phenotypic and genotypic methods. The incidence of Staphylococcus aureus was greater in goats (42.00%; 28.20 - 56.80%, confidence interval [CI] 95.00%) followed by cattle (13.50%; 9.20 - 18.80%, CI 95.00%), humans (12.90%; 9.30 - 17.40%, CI 95.00%) and dogs (12.90%; 8.10 - 19.20%, CI 95.00%). Significantly higher incidence of MRSA was observed in dogs (65.00%; 40.80 - 84.60%, CI 95.00%), compared to other hosts namely cattle (48.00%; 26.50 - 64.30%, CI 95.00%), humans (35.00%; 20.20 - 52.50%, CI 95.00%) and goats (10.00%; 1.20 - 30.40%, CI 95.00%). All the S. aureus isolates were further screened for thermostable nuclease (nuc gene) by polymerase chain reaction (PCR). The incidence of nuc gene in cattle, dog, goat and human were found to be 3.30% (1.30 - 6.60%, CI 95.00%), 5.20% (2.30 - 9.90%, CI 95.00%), 28.00% (16.20 - 42.50%, CI 95.00%) and 9.10% (6.00 - 13.00%, CI 95.00%), respectively. Comparative evaluation of two PCR primers (mecA-162 and mecA-310) indicated the former one as more rational choice for detection of MRSA. Overall, the results of our study indicated possible risk of zoonotic transmission of MRSA from canines.
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  • 文章类型: Journal Article
    未经证实:肝HBV抗原表达的模式已被描述,但未在单细胞分辨率下定量。我们将定量技术应用于慢性乙型肝炎患者的肝活检,并评估采样异质性,疾病阶段的影响,和核苷(t)ide(NUC)处理,以及肝脏和外周病毒生物标志物之间的相关性。
    UNASSIGNED:使用新型四重免疫荧光测定和图像分析对HBV核心和HBsAg阳性的肝细胞进行定量。在NUC治疗前后,从HBeAg阳性(n=39)和HBeAg阴性(n=75)参与者进行活检分析。为了评估抽样效果,比较了在同一时间点收集的重复活检.血清或血浆样品的HBVDNA水平进行了评估,HBsAg,乙型肝炎核心相关抗原(HBcrAg),和HBVRNA。
    未经证实:弥漫性分布的个体HBV核心+细胞和HBsAg+细胞病灶是最常见的染色模式。HBV核心和HBsAg阳性的肝细胞很少见。配对活检显示参与者体内HBV染色的大的局部变异,这在大型肝脏切除术中得到证实。NUC治疗与HBeAg阳性和HBeAg阴性参与者中HBV核心+细胞的中位频率>100倍降低相关,而HBsAg+细胞的减少没有统计学意义。在所有评估的时间点,HBeAg阴性参与者的HBV核心肝细胞的频率低于HBeAg阳性参与者。总HBV+肝细胞负荷与HBcrAg相关,HBVDNA,和HBVRNA仅在基线HBeAg阳性样品。
    未经证实:HBV核心+肝细胞减少与HBeAg阴性状态和NUC治疗相关。个体肝脏中HBV阳性的变化是广泛的。肝脏和外围之间的相关性仅在可能指示cccDNA的生物标志物之间发现(HBV核心+和HBcrAg,HBVDNA,和RNA)。
    未经证实:HBV感染肝肝细胞,它的基因组可以以两种形式存在,表达不同组的病毒蛋白:一个称为cccDNA的环状基因组,可以表达所有病毒蛋白,包括HBV核心和HBsAg蛋白,或插入宿主基因组通常表达HBsAg的线性片段,但不是HBV核心。我们使用新技术来确定表达HBV核心和HBsAg蛋白的肝细胞的百分比在一大组的肝活检。我们发现,表达的丰度和模式在患者组中甚至在单个肝脏内都不同,并且NUC治疗大大减少了核心表达肝细胞的数量。
    UNASSIGNED: Patterns of liver HBV antigen expression have been described but not quantified at single-cell resolution. We applied quantitative techniques to liver biopsies from individuals with chronic hepatitis B and evaluated sampling heterogeneity, effects of disease stage, and nucleos(t)ide (NUC) treatment, and correlations between liver and peripheral viral biomarkers.
    UNASSIGNED: Hepatocytes positive for HBV core and HBsAg were quantified using a novel four-plex immunofluorescence assay and image analysis. Biopsies were analysed from HBeAg-positive (n = 39) and HBeAg-negative (n = 75) participants before and after NUC treatment. To evaluate sampling effects, duplicate biopsies collected at the same time point were compared. Serum or plasma samples were evaluated for levels of HBV DNA, HBsAg, hepatitis B core-related antigen (HBcrAg), and HBV RNA.
    UNASSIGNED: Diffusely distributed individual HBV core+ cells and foci of HBsAg+ cells were the most common staining patterns. Hepatocytes positive for both HBV core and HBsAg were rare. Paired biopsies revealed large local variation in HBV staining within participants, which was confirmed in a large liver resection. NUC treatment was associated with a >100-fold lower median frequency of HBV core+ cells in HBeAg-positive and HBeAg-negative participants, whereas reductions in HBsAg+ cells were not statistically significant. The frequency of HBV core+ hepatocytes was lower in HBeAg-negative participants than in HBeAg-positive participants at all time points evaluated. Total HBV+ hepatocyte burden correlated with HBcrAg, HBV DNA, and HBV RNA only in baseline HBeAg-positive samples.
    UNASSIGNED: Reductions in HBV core+ hepatocytes were associated with HBeAg-negative status and NUC treatment. Variation in HBV positivity within individual livers was extensive. Correlations between the liver and the periphery were found only between biomarkers likely indicative of cccDNA (HBV core+ and HBcrAg, HBV DNA, and RNA).
    UNASSIGNED: HBV infects liver hepatocyte cells, and its genome can exist in two forms that express different sets of viral proteins: a circular genome called cccDNA that can express all viral proteins, including the HBV core and HBsAg proteins, or a linear fragment that inserts into the host genome typically to express HBsAg, but not HBV core. We used new techniques to determine the percentage of hepatocytes expressing the HBV core and HBsAg proteins in a large set of liver biopsies. We find that abundance and patterns of expression differ across patient groups and even within a single liver and that NUC treatment greatly reduces the number of core-expressing hepatocytes.
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  • 文章类型: Journal Article
    平场校正(FFC)通常用于图像信号处理(ISP)中以改善图像传感器像素的均匀性。已知图像传感器不均匀性和透镜系统特性是温度相关的。一些机器视觉应用,如视觉里程计和单像素机载目标跟踪,对像素到像素的灵敏度变化极为敏感。众多的摄像头,特别是在红外成像和凝视相机领域,使用多个校准图像来校正不均匀性。本文描述了用于机器视觉应用的两个当代全局快门CMOS图像传感器的暗信号不均匀性(DSNU)和光响应不均匀性(PRNU)的温度和模拟增益依赖性。提出了一种优化的硬件体系结构来补偿不均匀性,可选的参数镜头阴影校正(LSC)。针对不同的应用领域概述了三种不同的性能配置,成本,和功率要求。对于大多数商业应用,LSC的校正就足够了。对于DSNU和PRNU,用一个或多个校准图像进行补偿,在不同的增益和温度设置捕获的考虑。对于要求更高的应用,的有效性,外部内存带宽,功耗,实施,和校准的复杂性,比较了不同非均匀性校正方法的相机可制造性。
    Flat-field correction (FFC) is commonly used in image signal processing (ISP) to improve the uniformity of image sensor pixels. Image sensor nonuniformity and lens system characteristics have been known to be temperature-dependent. Some machine vision applications, such as visual odometry and single-pixel airborne object tracking, are extremely sensitive to pixel-to-pixel sensitivity variations. Numerous cameras, especially in the fields of infrared imaging and staring cameras, use multiple calibration images to correct for nonuniformities. This paper characterizes the temperature and analog gain dependence of the dark signal nonuniformity (DSNU) and photoresponse nonuniformity (PRNU) of two contemporary global shutter CMOS image sensors for machine vision applications. An optimized hardware architecture is proposed to compensate for nonuniformities, with optional parametric lens shading correction (LSC). Three different performance configurations are outlined for different application areas, costs, and power requirements. For most commercial applications, the correction of LSC suffices. For both DSNU and PRNU, compensation with one or multiple calibration images, captured at different gain and temperature settings are considered. For more demanding applications, the effectiveness, external memory bandwidth, power consumption, implementation, and calibration complexity, as well as the camera manufacturability of different nonuniformity correction approaches were compared.
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  • 文章类型: Journal Article
    Remdesivir是一种核苷酸类似物前药,自2019年12月COVID-19大流行爆发以来备受关注。GS-441524(Nuc)是雷米西韦的活性代谢产物,在COVID-19的临床治疗中起着关键作用。这里,在一步蛋白沉淀过程后,开发了一种稳健的HPLC-MS/MS方法来测定大鼠血浆样品中的Nuc浓度.色谱分离在WatersXBrigeC18柱(50×2.1mm,3.5μm)在梯度洗脱条件下。电喷雾正离子模式下的多个反应监测转变对于Nuc为m/z292.2→163.2,对于内标(卡马西平)为237.1→194.1。定量分析方法经充分验证符合美国食品和药物管理局指南。线性,准确度和精密度,基体效应,recovery,稳定性结果满足准则的要求。对测量不确定度和样品重分析结果进行分析,进一步保证了方法的稳健性和重现性。这种优化的方法成功地应用于大鼠的药代动力学研究中remdesivir(静脉给药,5mgkg-1)。该方法可以作为COVID-19患者进一步药代动力学和临床疗效研究的基础。图形抽象。
    Remdesivir is a nucleotide analog prodrug that has received much attention since the outbreak of the COVID-19 pandemic in December 2019. GS-441524 (Nuc) is the active metabolite of remdesivir and plays a pivotal role in the clinical treatment of COVID-19. Here, a robust HPLC-MS/MS method was developed to determine Nuc concentrations in rat plasma samples after a one-step protein precipitation process. Chromatographic separation was accomplished on Waters XBrige C18 column (50 × 2.1 mm, 3.5 μm) under gradient elution conditions. Multiple reaction monitoring transitions in electrospray positive ion mode were m/z 292.2 → 163.2 for Nuc and 237.1 → 194.1 for the internal standard (carbamazepine). The quantitative analysis method was fully validated in line with the United States Food and Drug Administration guidelines. The linearity, accuracy and precision, matrix effect, recovery, and stability results met the requirements of the guidelines. Uncertainty of measurement and incurred sample reanalysis were analyzed to further ensure the robustness and reproducibility of the method. This optimized method was successfully applied in a rat pharmacokinetics study of remdesivir (intravenously administration, 5 mg kg-1). The method can act as a basis for further pharmacokinetic and clinical efficacy investigations in patients with COVID-19. Graphical abstract.
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  • 文章类型: Comparative Study
    BACKGROUND: The climate crisis threatens sustainability of crop production worldwide. Crop diversification may enhance food security while reducing the negative impacts of climate change. Proso millet (Panicum milaceum L.) is a minor cereal crop which holds potential for diversification and adaptation to different environmental conditions. In this study, we assembled a world collection of proso millet consisting of 88 varieties and landraces to investigate its genomic and phenotypic diversity for seed traits, and to identify marker-trait associations (MTA).
    RESULTS: Sequencing of restriction-site associated DNA fragments yielded 494 million reads and 2,412 high quality single nucleotide polymorphisms (SNPs). SNPs were used to study the diversity in the collection and perform a genome wide association study (GWAS). A genotypic diversity analysis separated accessions originating in Western Europe, Eastern Asia and Americas from accessions sampled in Southern Asia, Western Asia, and Africa. A Bayesian structure analysis reported four cryptic genetic groups, showing that landraces accessions had a significant level of admixture and that most of the improved proso millet materials clustered separately from landraces. The collection was highly diverse for seed traits, with color varying from white to dark brown and width spanning from 1.8 to 2.6 mm. A GWAS study for seed morphology traits identified 10 MTAs. In addition, we identified three MTAs for agronomic traits that were previously measured on the collection.
    CONCLUSIONS: Using genomics and automated seed phenotyping, we elucidated phylogenetic relationships and seed diversity in a global millet collection. Overall, we identified 13 MTAs for key agronomic and seed traits indicating the presence of alleles with potential for application in proso breeding programs.
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  • 文章类型: Journal Article
    目的:牛奶生产是国民经济的主要支柱之一。这个行业的关键问题之一是亚临床乳腺炎,这损害了这个被认为是经济支柱的行业。它是一种传染性和人畜共患疾病;感染可以通过挤奶者的手在奶制品动物之间传播,还有挤奶机,而人类感染是由于食用表面上卫生的牛奶而发生的。金黄色葡萄球菌是临床和亚临床乳腺炎的主要致病因子之一。由于其作为肠毒素和中毒性休克综合征的毒力因子,它也被认为是人类食物中毒的细菌之一。本研究旨在评估金黄色葡萄球菌及其肠毒素的患病率,还有,从患有亚临床乳腺炎的奶牛收集的牛奶中的其他毒力因子。
    方法:从位于阿西乌特省的不同奶牛场收集60头牛,埃及。在取样之前,对这些奶牛进行乳房及其淋巴结的临床检查。从临床上健康的乳房收集牛奶样品。所有的牛奶样品通过加州乳腺炎试验(CMT)检查,聚合酶链反应(PCR),和酶联免疫吸附测定(ELISA)确认亚临床乳腺炎,在所检查的牛奶样品中存在金黄色葡萄球菌及其肠毒素基因和其他毒力因子。
    结果:本研究中包含的奶牛乳房健康。通过CMT测试了60个收集的牛奶样品。48/60(80.0%)为阳性样本;从48个阳性样本中,46份(95.83%)样品通过金黄色葡萄球菌16srRNAPCR检测证实为阳性。多重PCR证实一个样本中存在葡萄球菌肠毒素基因C(秒),23份样本中的葡萄球菌肠毒素基因D(SED),而ELISA测定证实仅在两个样品中存在相同的肠毒素。另一方面,在33个样品中发现了负责金黄色葡萄球菌一些其他毒力因子的其他基因组,如细胞外热稳定核酸酶(nuc)基因,而中毒性休克综合征(tsst)基因和甲氧西林克制金黄色葡萄球菌(mecA)基因在本研究中未检测到。
    结论:下临床乳腺炎是对动物和人类健康产生不利影响的隐藏因素之一。牛奶通常看起来很好,可以被人类特别是儿童食用;然而,它导致严重的公共卫生问题。此外,患有这种形式的乳腺炎的受感染动物可以将感染传播到其他产奶动物,并可能转变为传染性乳腺炎的临床病例,该病例可能通过动物扑杀或死亡而结束。金黄色葡萄球菌是引起牛隐性乳腺炎的主要原因之一。除了细胞外热稳定核酸酶(nuc)基因,葡萄球菌肠毒素基因C(sec)和葡萄球菌肠毒素基因D(sed)是在亚临床乳腺炎乳中证实的最常见的毒力基因。这些结果强调了需要在奶牛场采取更多的卫生措施,以避免在动物之间传播感染,以确保向人类生产安全健康的食品。
    OBJECTIVE: Milk production is one of the main props for the national economy. One of the crucial problems in this industry is subclinical mastitis, which harms this industry that considered the backbone of the economy. It is an infectious and zoonotic disease; the infection can spread between dairy animals through milkers\' hands, and milking machines, while the human infection occurs due to the consumption of apparently hygienic milk. Staphylococcus aureus is one of the main causative agents of clinical and subclinical mastitis. It is also considered one of the bacteria incriminated in food intoxication of humans due to its virulence factors as enterotoxins and toxic shock syndrome. The current study was designed to assess the prevalence of S. aureus and its enterotoxins, as well as, its other virulence factors in milk collected from cows that suffer from subclinical mastitis.
    METHODS: Sixty cows were collected from different dairy farms located in Assiut Governorate, Egypt. These cows were subjected to the clinical examination of the udder and its lymph nodes before sampling. Milk samples were collected from clinically healthy udders. All the milk samples were examined by California mastitis test (CMT), polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) for confirmation subclinical mastitis, presence of S. aureus and its enterotoxins genes and other virulence factors in the examined milk samples.
    RESULTS: The cows included in the current study had healthy udders. The sixty collected milk samples were tested by CMT. 48/60 (80.0%) were positive samples; from the 48 positive samples, 46 (95.83%) samples were confirmed positive by S. aureus 16s rRNA PCR assay. Multiplex PCRs confirmed the presence of staphylococcus enterotoxin gene C (sec) in one sample, staphylococcus enterotoxin gene D (sed) in 23 samples, while ELISA assay confirmed the presence of the same enterotoxin in only two samples. On the other hand, other groups of genes responsible for some other virulence factors of S. aureus like the extracellular thermostable nuclease (nuc) gene were found in 33 samples, while toxic shock syndrome (tsst) gene and methicillin restraint S. aureus (mecA) gene were not detected in this study.
    CONCLUSIONS: Subclinical mastitis is one of the hidden factors that adversely affect the health of both animals and humans. The milk is usually appeared good and may be consumed by humans especially children; however, it causes severe public health problems. In addition, the infected animals with this form of mastitis can spread the infection to other dairy animals and may be turned to a clinical case of contagious mastitis that may be ended by animal culling or death. S. aureus is one of the main causes of subclinical mastitis in cattle. In addition to extracellular thermostable nuclease (nuc) gene, staphylococcus enterotoxin gene C (sec) and staphylococcus enterotoxin gene D (sed) are the most common virulence genes confirmed in subclinical mastitis milk. These results highlighted the need to apply more hygienic measures in the dairy farms to avoid spreading the infection between animals to ensure the production of safe and healthy food to humans.
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  • 文章类型: Journal Article
    无人驾驶飞行器(UAV)配备有光学系统,包括红外(IR)相机,例如电光IR(EO/IR),目标获取和指定瞄准器(TADS),或前瞻性IR(FLIR)。然而,从红外相机获得的图像受到噪声的影响,如死像素,线条,和固定的模式噪声。非均匀性校正(NUC)是一种广泛用于降低红外图像噪声的方法。但它在消除操作过程中发生的噪声方面有局限性。已经提出了克服NUC方法局限性的方法,例如两点校正(TPC)和基于场景的NUC(SBNUC)。然而,这些方法仍然遭受不固定的模式噪声。在本文中,为了克服传统方法的局限性,提出了一种基于背景配准的自适应噪声滤波(BRANF)方法。所提出的BRANF方法利用背景配准处理和稳健主成分分析(RPCA)。此外,提出了图像质量验证方法,可以在没有地面实况图像的情况下定量测量噪声滤波性能。通过从实际军事光学系统获得的中波红外(MWIR)和长波红外(LWIR)图像进行了性能验证实验。因此,发现BRANF的图像质量改善率比传统NUC高30%。
    Unmanned aerial vehicles (UAVs) are equipped with optical systems including an infrared (IR) camera such as electro-optical IR (EO/IR), target acquisition and designation sights (TADS), or forward looking IR (FLIR). However, images obtained from IR cameras are subject to noise such as dead pixels, lines, and fixed pattern noise. Nonuniformity correction (NUC) is a widely employed method to reduce noise in IR images, but it has limitations in removing noise that occurs during operation. Methods have been proposed to overcome the limitations of the NUC method, such as two-point correction (TPC) and scene-based NUC (SBNUC). However, these methods still suffer from unfixed pattern noise. In this paper, a background registration-based adaptive noise filtering (BRANF) method is proposed to overcome the limitations of conventional methods. The proposed BRANF method utilizes background registration processing and robust principle component analysis (RPCA). In addition, image quality verification methods are proposed that can measure the noise filtering performance quantitatively without ground truth images. Experiments were performed for performance verification with middle wave infrared (MWIR) and long wave infrared (LWIR) images obtained from practical military optical systems. As a result, it is found that the image quality improvement rate of BRANF is 30% higher than that of conventional NUC.
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  • 文章类型: Evaluation Study
    Staphylococcus aureus is considered a major pathogen in veterinary and human medicine, and the emergence of multidrug-resistant strains, such as livestock-associated methicillin-resistant S. aureus, means that reliable, inexpensive, and fast methods are required to identify S. aureus obtained from animal sources. We tested the accuracy of a PCR targeting the genes femA, nuc, and coa in identifying S. aureus from animals. A total of 157 Staphylococcus spp. isolates were examined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry; 18 different Staphylococcus species were identified. Of 68 S. aureus isolates, the genes femA, nuc, and coa were found in 61, 53, and 32 isolates, respectively. Considering MALDI-TOF as the gold standard, the PCR assays targeting all 3 genes showed 100% specificity; the sensitivity values were 89.7, 77.9, and 47.0% for femA, nuc, and coa, respectively. Sensitivity was 100% when femA and nuc markers were targeted simultaneously. These results confirm PCR as an accurate method to identify S. aureus species from animal sources and strongly suggest the simultaneous use of primers targeting femA and nuc genes.
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