Impacts of grazing intensity, precipitation and temperature on productivity, forage quality, species composition and diversity in typical steppe of Inner Mongolia

The overall goal of this study is to analyze and evaluate the long-term effects of sheep grazing intensity on yield performance, herbage quality, species diversity and specie composition in grassland ecosystems in Inner Mongolia, and then to provide efficient practices preventing grassland degradation

Determination of dextromethorphan in rabbit plasma by LC-MS/MS and its application to pharmacokinetic study

A highly sensitive liquid chromatographic tandem mass spectrometric (LC-MS/MS) method for determination of dextromethorphan in rabbit plasma using triazolam as the internal standard (IS) was developed. Plasma samples were extracted with ethyl acetate and separated on a SB-C18 column with a mobile phase of acetonitrile-water 60:40 (v/v) at a flow of 0.3 mL/min. Detection is carried out by multiple reaction monitoring (MRM) on a ion-trap LC-MS/MS system with an electrospray ionization interface. The lower limit of quantification (LLOQ) was 1 ng/mL. After intravenous administration of a single dose of dextromethorphan 2 mg/kg, the main pharmacokinetic parameters were as follows: AUC0→t 636.13 ± 47.13 (ng/mL·h); CL 2.60 ± 0.24 (L/h), Cmax 874 ± 67.16 (ng/mL), Vz 1.58 ± 0.11 (L/kg), T1/2 2.41 ± 0.35 (h), MRT 1.26 ± 0.08 (h).Colegio de Farmacéuticos de la Provincia de Buenos Aire

Determination of dextromethorphan in rabbit plasma by LC-MS/MS and its application to pharmacokinetic study

A highly sensitive liquid chromatographic tandem mass spectrometric (LC-MS/MS) method for determination of dextromethorphan in rabbit plasma using triazolam as the internal standard (IS) was developed. Plasma samples were extracted with ethyl acetate and separated on a SB-C18 column with a mobile phase of acetonitrile-water 60:40 (v/v) at a flow of 0.3 mL/min. Detection is carried out by multiple reaction monitoring (MRM) on a ion-trap LC-MS/MS system with an electrospray ionization interface. The lower limit of quantification (LLOQ) was 1 ng/mL. After intravenous administration of a single dose of dextromethorphan 2 mg/kg, the main pharmacokinetic parameters were as follows: AUC0→t 636.13 ± 47.13 (ng/mL·h); CL 2.60 ± 0.24 (L/h), Cmax 874 ± 67.16 (ng/mL), Vz 1.58 ± 0.11 (L/kg), T1/2 2.41 ± 0.35 (h), MRT 1.26 ± 0.08 (h).Colegio de Farmacéuticos de la Provincia de Buenos Aire

Integrated siRNA design based on surveying of features associated with high RNAi effectiveness

BACKGROUND: Short interfering RNAs have allowed the development of clean and easily regulated methods for disruption of gene expression. However, while these methods continue to grow in popularity, designing effective siRNA experiments can be challenging. The various existing siRNA design guidelines suffer from two problems: they differ considerably from each other, and they produce high levels of false-positive predictions when tested on data of independent origins. RESULTS: Using a distinctly large set of siRNA efficacy data assembled from a vast diversity of origins (the siRecords data, containing records of 3,277 siRNA experiments targeting 1,518 genes, derived from 1,417 independent studies), we conducted extensive analyses of all known features that have been implicated in increasing RNAi effectiveness. A number of features having positive impacts on siRNA efficacy were identified. By performing quantitative analyses on cooperative effects among these features, then applying a disjunctive rule merging (DRM) algorithm, we developed a bundle of siRNA design rule sets with the false positive problem well curbed. A comparison with 15 online siRNA design tools indicated that some of the rule sets we developed surpassed all of these design tools commonly used in siRNA design practice in positive predictive values (PPVs). CONCLUSION: The availability of the large and diverse siRNA dataset from siRecords and the approach we describe in this report have allowed the development of highly effective and generally applicable siRNA design rule sets. Together with ever improving RNAi lab techniques, these design rule sets are expected to make siRNAs a more useful tool for molecular genetics, functional genomics, and drug discovery studies

Linking ethylene to nitrogen-dependent leaf longevity of grass species in a temperate steppe

Author's manuscript made available in accordance with the publisher's policy.Background and Aims Leaf longevity is an important plant functional trait that often varies with soil nitrogen supply. Ethylene is a classical plant hormone involved in the control of senescence and abscission, but its role in nitrogen-dependent leaf longevity is largely unknown. Methods Pot and field experiments were performed to examine the effects of nitrogen addition on leaf longevity and ethylene production in two dominant plant species, Agropyron cristatum and Stipa krylovii, in a temperate steppe in northern China. Key Results Nitrogen addition increased leaf ethylene production and nitrogen concentration but shortened leaf longevity; the addition of cobalt chloride, an ethylene biosynthesis inhibitor, reduced leaf nitrogen concentration and increased leaf longevity. Path analysis indicated that nitrogen addition reduced leaf longevity mainly through altering leaf ethylene production. Conclusions These findings provide the first experimental evidence in support of the involvement of ethylene in nitrogen-induced decrease in leaf longevity

Effects of yeast extract supplemented in diet on growth performance, digestibility, intestinal histology, and the antioxidant capacity of the juvenile turbot (Scophthalmus maximus)

An 8-week feeding experiment was conducted on the juvenile turbot (Scophthalmus maximus) to evaluate the influence of yeast extract (YE) supplementation in the diet on growth performance, feed utilization, body composition, nutrient digestibility, intestinal histology, and antioxidant capacity. Four experimental diets were formulated with graded levels of yeast extract 0 (YE0), 1% (YE1), 3% (YE3), and 5% (YE5) and fed to turbots (initial body weight: 4.2 ± 0.1 g) with three replicates per diet and 200 fish in each replicate, respectively. The results showed that turbots fed with diets YE1 and YE3 displayed a significantly higher specific growth rate and protein efficiency rate than those fed with diets YE0 and YE5, while the feed conversion ratios in YE1 and YE3 groups were lower than those in YE0 and YE5. Fish fed with diets YE3 and YE5 showed higher body crude protein contents than those in groups YE0 and YE1. The highest apparent digestibility coefficients for dry matter and crude protein, digestive enzyme activities (trypsin, lipase, and amylase), and the height of the intestinal fold were observed in the YE3 group. YE3 treatment displayed a significantly higher superoxide dismutase (SOD) activity than the YE0 group, while the malondialdehyde (MDA) content in YE1 was significantly lower than those in YE0 and YE5. No significant difference was observed in serum physiological and biochemical parameters among all treatments. Overall, appropriate dietary supplementation of the yeast extract could improve the growth performance, digestibility, and antioxidant capacity of the juvenile turbot, and the recommended yeast extract level in the feed is 2.47%

NEW LATE JURASSIC PALEOMAGNETIC RESULTS FROM SHARILYN FORMATION, SOUTHERN MONGOLIA, AMURIA BLOCK, AND THEIR IMPLICATIONS FOR THE TECTONIC EVOLUTION OF THE MONGOL–OKHOTSK SUTURE

The Amuria block occupies the eastern part of the Central Asian Orogenic Belt between the Siberia craton and the North China block (NCB) and bears important information to understand the evolution of the MongolOkhotsk suture and the amalgamation of East Asia. However, the paleomagnetic database of Amuria remains very poor.The Amuria block occupies the eastern part of the Central Asian Orogenic Belt between the Siberia craton and the North China block (NCB) and bears important information to understand the evolution of the MongolOkhotsk suture and the amalgamation of East Asia

Nanostructured conformal hybrid solar cells: a promising architecture towards complete charge collection and light absorption

We introduce hybrid solar cells with an architecture consisting of an electrodeposited ZnO nanorod array (NRA) coated with a conformal thin layer (< 50 nm) of organic polymer-fullerene blend and a quasi-conformal Ag top contact (Thin/NR). We have compared the performance of Thin/NR cells to conventional hybrid cells in which the same NRAs are completely filled with organic blend (Thick/NR). The Thin/NR design absorbs at least as much light as Thick/NR cells, while charge extraction is significantly enhanced due to the proximity of the electrodes, resulting in a higher current density per unit volume of blend and improved power conversion efficiency. The NRAs need not be periodic or aligned and hence can be made very simply

Changing sources and burial of organic carbon in the Chukchi Sea sediments with retreating sea ice over recent centuries

Decreasing sea ice extent in summer caused by climate change is affecting the carbon cycle of the Arctic Ocean. In this study, surface sediments across the western Arctic Ocean are investigated to characterize sources of sedimentary organic carbon (OC). Bulk organic parameters (total organic carbon, total nitrogen, &delta;13Corg and &delta;15N) combined with molecular organic biomarkers (e.g., sterols and highly branched isoprenoids (HBIs)) are applied to distinguish between sympagic, pelagic, and terrestrial OC. Furthermore, downcore profiles of these parameters were also generated from the Chukchi Sea R1 core (74&deg; N) to evaluate changes in the relative contribution of these three components of sedimentary OC over the last 200 years with decreasing sea ice. Our data evidence that from 1820s to 1930s, prevailing high and variable sea ice cover inhibited in situ primary production resulting in prominent land-derived material stored in sediments. From 1930s to 1980s, with the gradual decline of sea ice, primary production increased progressively. The ratio of sympagic and pelagic OC began to rise to account for a larger portion of sedimentary OC. Since 1980s, accelerated sea ice loss led to enhanced primary production, stabilizing over the last decades due to freshwater induced surface ocean stratification in summer.</p