Nitrochromeazo titrimetric determination of sulfate in irrigation and other saline waters

Abstract

Sulfate in various types of aqueous solutions such as soil‐water extracts, sewage effluents, irrigation water, and well water can be determined rapidly and accurately by a volumetric technique. The indirect method is based on the formation of the barium‐nitrochromeazo complex. Using a water‐acetone medium sharpens the end point and adding NH₄F at low pH controls interferences.     

烤烟底色参比样制作及特征描述研究

从全国各地烤烟样品中筛选出能够表现底色特征的烟叶样品300片,制作不同颜色标度的烟叶底色参比样,并进行重复性和适应性测试,初步确定烟叶底色参比样各个标度的文字描述标准,探讨底色参比样在烟叶分级和产区识别上的应用。     

Structure and characterization of Chinese fir (Cunninghamia lanceolata) wood/MMT intercalation nanocomposite (WMNC)

With water-soluble phenol-formaldehyde resin as an intermediate, Chinese fir (Cunninghamia lanceolata) wood/montmorillonite nanocomposite (WMNC) was prepared through vacuum impregnation and characterized with XRD, SEM, FTIR and TG-DTA analyses. The XRD analysis indicated that the wood crystallinity of WMNC decreased, the MMT exfoliated and some nano silicate layers entered into the non-crystallized microfibrillar region of the wood cell wall. Wood structure is anisotropic and its impregnation is anisotropic. Due to the nonuniformity of the MMT organic modification, PF intercalation and wood impregnation, the MMT configuration and distribution in wood were diverse. The SEM graphs of WMNC showed that some silicate grains were blocked in the wood cell lumen, some silicate layers adhered to the inner surface of the wood cell wall, and some exfoliated MMT layers even penetrated the wood cell wall. The obtained hydroxyl of WMNC increased and its ether linking decreased. It was considered that MMT and wood interacted not only with hydroxyl bonds, but also involved some chemical linking. Compared with untreated wood and the PF-impreg, the pyrolysis process of WMNC changed; its starting decomposing temperature decreased and its pyrolysis weight loss at high temperatures greatly decreased. The WMNC indicated certain nanoeffects of the composition of the inorganic MMT nanolamellae. __________ Translated from Journal of Beijing Forestry University, 2007, 29(1): 131–135 [译自: 北京林业大学学报]     

SDG分离富集5-Br-PAN-S光度法测定水样中微量铁的研究

研究了铁 (Ⅱ )与5 -Br -PAN -S的显色条件。在 pH3.5～11的缓冲液中 ,形成1∶2型的稳定配合物 ,配合物的最大吸收峰位于540nm和740nm波长处 ,740nm处的表观摩尔吸光系数(ε=1.90×104L/(mol·cm)。铁量在0～80μg/25mL范围内符合比尔定律。采用巯基葡聚糖凝胶(SDG)分离干扰离子富集铁 ,提高了方法的选择性。     

猪圆环病毒3型TaqMan-MGB荧光定量PCR方法的建立及应用

为建立猪圆环病毒3型(PCV3)荧光定量PCR检测方法,本研究根据GenBank中PCV3基因序列设计特异性引物和探针,经过反应体系和条件优化,建立了特异性检测PCV3的TaqMan-MGB荧光定量PCR方法。该检测方法在4.78×10~1拷贝/μL～4.78×10~9拷贝/μL质粒标准品范围内均有良好的线性关系;该方法特异性试验结果显示,其与多种常见猪病病毒均无交叉反应,特异性良好;本研究建立的方法敏感性是常规PCR方法的100倍,敏感性较高;批内批间重复性试验变异系数均小于2.3%,重复性良好。对临床样品的检测结果显示,该方法对PCV3的检出率高于常规PCR方法,并且PCV3阳性样品多存在混合感染情况。该方法的建立为PCV3的实验室诊断及流行病学调查提供了快速、准确的检测手段。     

Prevalence of bovine genital campylobacteriosis and trichomonosis of bulls in northern Nigeria

Background

A survey was conducted to determine the prevalence of campylobacteriosis and trichomonosis, and their concurrence with brucellosis, in cattle in three states of northern Nigeria.

Methods

A total of 602 preputial samples was collected from bulls in 250 herds and tested using culture and identification. Various indigenous and exotic breeds were studied and four major management systems were encountered. Age of the cattle was estimated using dentition, farm records or cornual rings.

Results

The estimated true animal-level prevalence of Campylobacter fetus infection was 16.4% (95% CI: 13.0-20.7), of which 18.5% was C. f. fetus and 81.5% was C. f. venerealis. Of the latter, 92% were C. f. venerealis biovar intermedius strains. Animal-level prevalences in Adamawa, Kano and Kaduna states were 31.8%, 11.6% and 8.3% respectively, and were highest in bulls >7 years old (33.4%) and in the Gudali breed (28.8%). Of the 250 herds, 78 (25.5%, 95% CI: 19.4-32.7) had at least one infected bull, and herd prevalence was highest in the pastoral management system (43.5%). After adjustment for confounding using multivariable analysis, the odds of C. fetus infection were highest in Adamawa state (P < 0.01), in the pastoral management system (P < 0.01), and in bulls >7 years old (P = 0.01), and tended to be higher in Bos taurus breeds (P = 0.06). There was a strong positive association between the presence of campylobacteriosis and brucellosis (P < 0.01), both within bulls (OR = 8.3) and within herds (OR = 16.0). Trichomonosis was not detected in any herds.

Conclusion

Bovine genital campylobacteriosis is prevalent particularly in the pastoral management system in northern Nigeria, with C. f. venerealis biovar intermedius as the major aetiology. There was a strong positive correlation between the occurrence of campylobacteriosis and brucellosis. No evidence of trichomonosis was found in herds in this study.     

棉花正反交组合F1代性状的比较研究

按不完全双列杂交,以美国抗虫棉品种A1～A6为父本,国内常规棉品种B7～B12为母本,得到正交组合36个;以B系列为父本,A系列为母本,得到反交组合36个。2002年在湖南长沙、宁乡、南县、澧县4个实验点进行组合F1代产量、纤维品质、抗虫性等性状的正反交比较试验。结果表明:棉花纤维品质在正反交间无差异,棉花纤维品质性状遗传为非细胞质遗传;无论是子棉产量还是皮棉产量,抗虫杂交棉正、反交F1代间存在极显著差异,而且在构成产量的各个因子中,铃重在正反交间的差异达到了显著水平;从抗虫性方面看,正交组合的抗虫性稍好,其中对四代棉铃虫的抗性,正反交间差异达极显著水平。     

First molecular study of Canine herpesvirus-1 in reproductive specimens of adult dogs in southeast of Iran

Canine herpesvirus-1 (CHV-1) is recognized to be enzootic in the dog population with a widespread distribution. This pathogen leads to a lethal generalized illness in newborn puppies and is associated with reproductive disorders. CHV-1 should be considered as an important pathogen of neonatal death and infertility; so, it appears to pose a threat for breeding kennels. Although serologic data point to the circulation of CHV-1 among dogs of Iran are available, no definitive diagnosis has been conducted based on the molecular assay. So, this research was done to detect the prevalence of CHV-1 in dogs of Kerman. In this study, the presence of CHV-1 in vaginal specimens and biopsies of the uterus of dogs referring to the Veterinary Hospital of Shahid Bahonar University of Kerman was determined. Fifteen uterine samples and seven vaginal samples were included in group of the pregnant dogs. Moreover, thirteen uterine samples and twenty vaginal samples were related to the dogs displaying suspicious clinical signs such as reproductive disorders. Samples were collected and evaluated using real-time PCR. Viral DNA was detected in 21 samples from a total of 140 (15 %) collected samples which were related to 14 uterine samples (20 %) and 7 (10 %) vaginal specimens. The association of this virus with age, breed, housing, pregnancy and reproductive disorders was not significant. Five positive reproductive samples were belonged to the dogs with a history of reproductive disorders including pyometra, metritis, stillbirths, vaginitis and vaginal prolapse. This study is the first molecular detection of CHV-1 in reproductive samples of dogs in Iran. Considering the significant prevalence of this virus, it is necessary to carry out management measures in controlling and preventing this disease. Tracing CHV-1 requires further research on this virus in dogs of this region.     

家蚕五龄后部丝腺蛋白质构成与茧层量的关系

家蚕 5龄期是后部丝腺细胞大量合成并分泌蚕丝主要成分丝素蛋白的时期 ,对这一时期后部丝腺细胞的蛋白质构成进行研究 ,有利于发现丝腺细胞分泌丝素蛋白有关的功能蛋白质 ,阐明蚕茧高产的机理。采用蛋白质双向电泳和图像分析技术 ,研究发现家蚕同一品种的不同个体 ,或同一个体不同部位的后部丝腺细胞蛋白质的构成基本一致。该结果反映了家蚕同一品种不同个体后部丝腺细胞的新陈代谢水平基本没有差异 ,家蚕品种个体间茧层量差异 ,可能是个体生长发育和后部丝腺细胞数的不同等原因造成 ,而与每一个体后部丝腺细胞的新陈代谢关系不显著。该结果也说明在目前双向电泳技术和染色技术的条件下进行家蚕后部丝腺蛋白质组研究时 ,从家蚕同一品种的任一个体、任一部位提取后部丝腺细胞的蛋白质样品 ,所得的蛋白质双向电泳结果基本相同