Magnetic resonance studies of lunar samples

Electron spin resonance searches at 9.5 gigahertz on several fines samples and portions of several rocks have yielded signals whose lineshapes and temperature dependences show that the samples are principally ferromagnetic in nature. Proton magnetic resonance searches at 60 megahertz of these samples have not revealed any signals ascribable to water or any other types of hydrogen in concentrations greater than 0.0001 percent by weight contained in narrow lines (5 oersteds wide or less) and 0.01 percent by weight in wide lines (as wide as 100 oersteds).     

Profiling and characterization antioxidant activities in Anoectochilus formosanus hayata

Phytochemical characteristics and antioxidant activities of the crude and fractionated plant extracts of Anoectochilus formosanus were evaluated using five different assay systems. An acid-treatment (2 N HCl in 95% ethanol) was employed to treat a butanol fraction (BuOH), creating an acid-hydrolyzed BuOH fraction. The IC(50) values for DPPH radicals in the BuOH and acid-hydrolyzed BuOH fractions were 0.521 and 0.021 mg/mL, respectively. The acid-hydrolyzed BuOH exhibited approximately 5-fold higher activity in scavenging superoxide anion than catechin. The acid-hydrolyzed BuOH fraction also effectively protected phi x174 supercoiled DNA against strand cleavage induced by H(2)O(2) and reduced oxidative stress in HL-60 cells. Metabolite profiling showed that the aglycones of flavonoid glycosides in BuOH were produced after acid hydrolytic treatment, and this resulted in a significant increase in antioxidant activities of acid-hydrolyzed BuOH. One new diarylpentanoid, kinsenone, and three known flavonoid glycosides and their derivatives were identified for the first time from A. formosanus, with strong antioxidant properties.     

Bioguided fractionation and isolation of free radical scavenging components from in vitro propagated chinese medicinal plants Dendrobium tosaense Makino and Dendrobium moniliforme SW

This study was performed to investigate the free radical scavenging active components from in vitro propagated medicinal herbs of the genus Dendrobium, namely, Dendrobium tosaense Makino and Dendrobium moniliforme SW, using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical antioxidative assay. Seeds of the capsules derived after 12 weeks of hand-pollination germinated asymbiotically (50-74%) on half-strength Murashige and Skoog's (MS) basal medium with 3% sucrose and solidified with 0.9% Difco agar. Active growth in the germinated seedlings was achieved by reculturing on full-strength MS basal medium supplemented with 8% banana homogenate, 8% potato homogenate, 8% coconut water, 1.5% sucrose, and 0.9% Difco agar. Healthy plantlets transferred to plastic trays containing moss or moss and tree fern successfully acclimatized (84-100%) in the greenhouse. Extracts were prepared from plants grown in the greenhouse for a period of 6 months. Methanolic extracts of D. tosaense and D. moniliforme scavenged DPPH at 95.9 and 83.4%, respectively, at a concentration of 0.4 mg/mL. Therefore, methanolic solubles of D. tosaense and D. moniliforme were subjected to bioguided fractionation and separation by column chromatographic methods individually. After chromatographic separation of these crude extracts, the obtained fractions (Dm 1, Dm 2, Dm 3, Dt 1, Dt 2, and Dt 3) were tested for their activity. Among them, fractions Dm 2 and Dt 1 showed significant antioxidant activity by DPPH radical antioxidative assay. Active fractions were purified further by column chromatography and resulted in identification of the antioxidant components alkyl ferulates from D. moniliforme and quercetin from D. tosaense.     

Tipburn of Chinese cabbage in relation to calcium nutrition and distribution

Heading Chinese cabbage (Brassica campestris ssp. pekinensis Rupr.) grown with low Ca or B developed dark tan lesions near the leaf margins. A synergistic effect of low Ca and low B accompanied the development of this symptom. Plants grown under humid conditions were free of tipburn. Plants grown under less humidity developed tipburn. Total chemical analysis revealed a steady decrease in total Ca from the outer to the inner leaves. Fractional chemical analysis showed 7 times more water-soluble Ca in the outer than in the inner leaves, and 2 times more 1 N NaCl-soluble Ca in the outer than in inner leaves. Threshold concentration of water-soluble forms of Ca for tipburn was around 3.0 mg/g dry weight. Data suggest that root pressure flow is required to move adequate amounts of water-soluble Ca to the wrapper leaves to prevent tipburn of Chinese cabbage.     

猪败血型链球菌病的诊疗报告

本文阐述了猪链球菌病的临床症状、实验室检验及防治方法，力求为科学防控猪链球菌病提供有益的探索和参考。     

Dimethyl disulfide is an induced systemic resistance elicitor produced by Bacillus cereus C1L

BACKGROUND: Bacillus cereus C1L is a plant growth‐promoting rhizobacterium and can elicit induced systemic resistance (ISR) in plants against necrotrophic pathogens. However, little is known about ISR elicitors produced by B. cereus C1L, and no ISR elicitor has been identified and characterised. Therefore, the objective of this study is to identify volatile ISR elicitor(s) produced by B. cereus C1L. RESULTS: The volatile metabolites produced by B. cereus C1L were extracted, separated and identified by solid‐phase microextraction, gas chromatography and mass spectrometry. Dimethyl disulfide (DMDS) was the only separated metabolite being determined. Afterwards, application of DMDS by means of soil drench significantly protected tobacco and corn plants against Botrytis cinerea and Cochliobolus heterostrophus, respectively, under greenhouse conditions. The results reveal that DMDS could play an important role in ISR by B. cereus C1L. CONCLUSION: This is the first report of DMDS as an elicitor produced by an ISR‐eliciting B. cereus strain and its ability to suppress plant fungal diseases under greenhouse conditions. It is suggested that DMDS has potential for practical use in controlling plant foliar diseases besides soil fumigation. Copyright © 2012 Society of Chemical Industry     

Quantum dots for live cells, in vivo imaging, and diagnostics

Research on fluorescent semiconductor nanocrystals (also known as quantum dots or qdots) has evolved over the past two decades from electronic materials science to biological applications. We review current approaches to the synthesis, solubilization, and functionalization of qdots and their applications to cell and animal biology. Recent examples of their experimental use include the observation of diffusion of individual glycine receptors in living neurons and the identification of lymph nodes in live animals by near-infrared emission during surgery. The new generations of qdots have far-reaching potential for the study of intracellular processes at the single-molecule level, high-resolution cellular imaging, long-term in vivo observation of cell trafficking, tumor targeting, and diagnostics.     

Differentiation of two powdery mildews of sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis>) by a PCR-mediated method based on ITS sequences

Powdery mildew can be found in most sunflower fields during the winter season in Taiwan and causes severe yellowing on the blade, petiole, stem, and calyx, as well as serious defoliation. Two types of powdery mildew fungi isolated from sunflower leaves showed variable status for fibrosin bodies. But only the cleistothecium of Podosphaera xanthii, one of the pathogens causing this disease, was observed on samples from Chungpu County at the beginning of 2005. With a species-specific primer pair, PN23/PN34, no specific PCR product was amplified from the pathogen’s genomic DNA. Based upon the ITS sequence of rDNA, three PCR primer sets (S1/S2, G1/G2, and L1/L2) specific to P. xanthii, Golovinomyces cichoracearum and Leveillula taurica, respectively, were designed to detect and differentiate pathogens causing powdery mildews on sunflower. Only the primer pairs S1/S2 and G1/G2 could amplify PCR products, with product sizes of 454 and 391 bp, respectively. Four samples of fungal DNA were subjected to a multiplex PCR amplification with primer pairs S1/S2 and G1/G2; P. xanthii and G. cichoracearum were successfully detected. These results suggest that the multiplex PCR method is a rapid, simple, and effective technique to detect and differentiate powdery mildews, for example P. xanthii and G. cichoracearum, found on sunflower. With morphologic characteristics, ITS sequence analysis and pathogenicity testing, P. xanthii and G. cichoracearum, the first case, are two powdery mildews on sunflower in Taiwan.