白斑狗鱼StAR基因克隆及其表达分析

【目的】克隆白斑狗鱼（Esox lucius）类固醇激素合成急性调节蛋白（StAR）基因（ElStAR）并分析其组织表达差异,为开展StAR基因生物学功能研究及揭示白斑狗鱼性腺发育机制提供基础资料。【方法】根据GenBank已公布的白斑狗鱼基因组测序结果（NC_047581.1）设计特异性引物,采用RT-PCR克隆ElStAR基因cDNA序列,通过ClustalX、ExPASy、TargetP 1.1、TMHMM 2.0和SignalP 5.0等在线软件进行生物信息学分析,并采用实时荧光定量PCR进行ElStAR基因组织表达定量分析。【结果】ElStAR基因cDNA序列长度1485 bp,其开放阅读框（ORF）为864 bp,共编码287个氨基酸残基;ElStAR氨基酸序列与北极红点鲑StAR氨基酸序列的相似性最高（93.33%）,与海鳟、条纹鲈鱼、金头鲷、大菱鲆、斑马鱼、半滑舌鳎的相似性均高于75.00%,而与小家鼠的相似性最低（59.15%）;基于StAR氨基酸序列相似性构建的系统发育进化树也显示白斑狗鱼与北极红点鲑和海鳟等鲑科鱼类处于同一分支。ElStAR蛋白相对分子量为32.23 kD,理论等电点（pI）为8.98,为不稳定的亲水性蛋白;具有START结构域,无信号肽及跨膜结构,符合线粒体靶向肽的基本特征。ElStAR蛋白二级结构由α-螺旋（占40.77%）、无规则卷曲（占35.89%）、延伸链（占18.12%）和β-折叠（占5.23%）组成,其三级结构是由α-螺旋配合多个β-折叠卷曲盘旋而成。ElStAR基因在白斑狗鱼精巢、卵巢、头肾、肝脏、肌肉及脑组织中均有不同程度的表达,且在精巢中的相对表达量极显著高于在卵巢中的相对表达量（P<0.01）,呈明显的性别二态性表达模式。【结论】ElStAR基因编码蛋白结构和功能十分保守,具有典型的START结构域,对胆固醇的运输和调节起重要作用。ElStAR基因在白斑狗鱼精巢及卵巢中的表达存在极显著差异,可能在维持白斑狗鱼精巢的发育形成中发挥重要作用。     

A novel eco-friendly colorant and dyeing method for poly(ethylene terephthalate) substrate

Although madder (Rubia tinctorum) has been used as a well-known natural textile dye source for dyeing of natural fibers such as wool, silk and cotton, 100 % polyester dyeing with madder is not common. In this study, polyester samples were dyed with madder at different dyeing temperatures, from 60 °C to 130 °C, in company with 7 chemical and 5 natural mordants. Color properties and rub, light and wash fastness performances were investigated. Different shades of orange, brown, pink and reddish green colors were obtained. Dyeing at 130 °C exhibited the highest color yield, the highest chroma and the lowest lightness values. Overall, chemical mordants exhibited higher color yields than natural mordants. High wash fatness, moderate light and rub fastness levels were observed. The potassium bitartrate and gallnut, a natural mordant, exhibited the best results. The madder dyeing of polyester should be carried out at hot temperature conditions, 130 °C, in order to obtain the highest achievable color yield and chroma with the highest light and wash fastness properties.     

Optimal isotherm model and explanatory characteristics associated with metal ion adsorption on humic acids isolated from forest soils

Journal of Soils and Sediments - Understanding the mechanisms of interaction between humic acids (HAs) and metal ions in soil media is essential for integrated environmental and agricultural...     

Shift work as an oxidative stressor

Background  

Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders.     

Long-term land-use change effects on phosphorus fractionation in Zrêbar Lake margin soils

The aim of this study was to survey long-term changes in phosphorus (P) fractions in soils in different land uses. Sequential extraction had been used to determine soil P fractionation on the basis of land-use change, i.e. native forest to vineyard and wetland to both alfalfa and wheat at the end of 30 and 20 years, respectively. The highest values of labile-P (L-P) fractions in surface soil layers were observed in the cultivated land. The calcium-bound P was the most affected fraction by land-use change with the lowest amount in the vineyard and the highest amount in the alfalfa land. Conversion of forest to vineyards causes P in the soils to be more vulnerable to transmission; thus, the least amount of total P (T-P) in vineyard may be attributed to the removal of sediment and sediment bond P from runoff in response to land-use changes. Average L-P in alfalfa land was two times more than that in vineyard. Results showed that 44.5% of T-P in native land was stored in surface layer; besides, the portion of the arable surface horizon in T-P sequestration was 33%.     

A model to predict the dry matter and yield of rapeseed under salinity and deficit irrigation

In this investigation, a model was developed to predict dry matter, seed yield and other crop parameters of rapeseed under deficit irrigation and salinity by using soil water and salt budget and other simple plant physiological relationships. Two-year experimental data were used. In calibration and validation of the presented model, results indicated that the model was able to estimate evapotranspiration, soil water content, leaf area index, evaporation, crop transpiration, dry matter and seed yield of rapeseed properly. The advantage of this model is its simplicity and easy calibration in other areas and climate conditions and it can be used to estimate yield and other crop parameters with common measurable data in the field. Prediction of crop yield by this model can be used for better management of agronomic systems to reduce administrative costs and in different environmental conditions. Finally, under scarce data, arid and semi-arid environments, this model is proposed to be used by irrigation managers and agricultural advisors.     

DISTRIBUTION AND PHYTOAVAILABILITY PREDICTION OF ZINC IN AGRICULTURAL CALCAREOUS SOILS

The extractability and distributions of zinc (Zn) were evaluated in calcareous agricultural soils from South-West Iran. Both single [diethylenetriaminepentaacetic acid (DTPA)] and sequential extraction procedures (Singh scheme) were applied to 20 representative soils. The DTPA extractable zinc levels were low (on average 3.34%). The sequential extraction procedures were also utilized for the study of zinc phytoavailability in maize plants (Zea mays L.) in a greenhouse experiment. The Singh scheme was significantly better than DTPA plus soil properties in phytoavailability prediction of zinc in soils. Significant correlations were found between the amounts of DTPA extractable zinc and the iron (Fe) oxides-bound (AFe and CFe) and residual fractions extracted by the Singh procedure. Zinc concentrations in plant samples (mean value of 27.49 mg kg^?1) were poorly correlated with the different extracted soil fractions (single and sequential). The Singh procedure provided better predictions of zinc uptake by plants than DTPA extraction method.     

Barley forages for modern global ruminant agriculture: A review

Ruminants have evolved on forages that comprise major portions of most modern dairy and beef cattle diets. Cattle require minimum amount of effective fiber to maintain healthy rumen conditions. However, high fibre levels limits feed intake. Dietary fiber levels and physical properties contribute to such hypophagia. Forage bulkiness, particle size, lignification and rumen passage rate determine fiber quality. Barley forage (BF, Hordeum vulgare, L.) serves dairy diets where and when alfalfa or corn silages are less accessible. Being lower in protein, intermediate in soluble protein, and higher in starch and cellulose, barley silage (BS) is a suitable replacement for alfalfa silage. Barley forages have usually lower fiber levels among winter cereal crops. Barley forages may not reduce feed intake as much as other cereal crops, notably triticale and oats. Beef studies suggest superior or similar weight gain and feed efficiency by feeding BS versus wheat, triticale and oat silages. Growth response to BS appears comparable to corn silage. Reduced BS particle size reduces chewing activity in lactating cows, and even with adequate fiber intake has little effect on milk fat. Inoculants containing Lactobacillus buchneri, Lactobacillus plantarum, Pediococcus pentosaceus, and Propionibacterium freudenreichii along with carbohydrases can lower silage pH and improve organic acids production and silage aerobic stability. Altered barley silage chop length alters chewing activity but not necessarily rumen pH. Maturity stage affects nutritional value of BF due to altered protein and fiber contents and rumen fermentation patterns. Genetic variance among BF cultivars can affect nutrient profiles and rumen digestibility. Barley forages are cost-effective entities along with alfalfa hay and silage and corn silage for environmentalist ruminants to host optimal rumen and peripheral nutrient metabolism. Adequate effective fiber with sufficient but not very high fermentable starch, and modest degradable proteins make BF a unique ingredient for the sustainable modern ruminant production.     

Preparation of extract-loaded nanocapsules from Onopordon leptolepis DC.

Sesquiterpenes have antifungal, antibacterial, and anesthetic properties. It is also thought that they prevent migraines and can be used as antibiotics and to treat malaria, but there are very few in-depth testing results available to support these claims. Nanocapsules coated by medicinal plants have many applications in drug manufacturing. Medicinal plants can be loaded on nanocapsules with the polyester triblock copolymer polyethylene glycol-polybutylene adipate-polyethylene glycol (PEG-PBA-PEG) as the shell and olive oil as the core by a process known as the polymer deposition solvent evaporation method. It has been shown that the size of nanocapsules depends on a variety of factors, such as the ratio of polymer to oil, concentration of polymers, and concentration of plant extract. In this research we attempted to prepare nanocapsules by emulsification of a mixture of onopordopicrin extracted from Onopordon leptolepis DC., polymer, acetone, and olive oil in aqueous phase without using surfactant. The nanocapsules were characterized by scanning electron microscopy and zeta potential sizer.     

Restless Legs Syndrome in shift workers: A cross sectional study on male assembly workers

Background  

Restless Legs Syndrome (RLS) is a common neurological movement disorder characterized by symptoms that follow a circadian pattern. Night and rotating shift work schedules exert adverse effects on functions of the human body by disturbing circadian rhythms, and they are known to cause sleep disturbances and insomnia. In this paper, we investigate the possible association between shift work and RLS.