Experimental and theoretical differential cross sections for a four-atom reaction: HD + OH → H₂O + D

Quantum dynamical theories have progressed to the stage in which state-to-state differential cross sections can now be routinely computed with high accuracy for three-atom systems since the first such calculation was carried out more than 30 years ago for the H + H(2) system. For reactions beyond three atoms, however, highly accurate quantum dynamical calculations of differential cross sections have not been feasible. We have recently developed a quantum wave packet method to compute full-dimensional differential cross sections for four-atom reactions. Here, we report benchmark calculations carried out for the prototypical HD + OH → H(2)O + D reaction on an accurate potential energy surface that yield differential cross sections in excellent agreement with those from a high-resolution, crossed-molecular beam experiment.     

Effects of soybean isoflavones on reproductive parameters in Chinese mini-pig boars

Background

Soybean isoflavones are structurally similar to mammalian estrogens and therefore may act as estrogen agonists or antagonists. However, it has not been determined if they have any negative effects on reproductive parameters in male livestock. Therefore, the objective of this study was to evaluate the effects of soybean isoflavones on male reproduction using Chinese mini-pig boars as a model. Fifty Xiang boars were randomly divided into five groups and fed diets containing 0, 125, 250, or 500 ppm soybean isoflavones or 0.5 ppm diethylstilbestrol for 60 days.

Results

Dietary supplementation with 250 ppm of soy isoflavones markedly increased the testis index (P < 0.05), fructose content (P < 0.05), and α-glycosidase content in testicular tissue (P < 0.01), as well as increased the number of viable germ cells (P < 0.01) and the level of Bcl-2 protein (P < 0.01). However, 500 ppm of soybean isoflavones significantly reduced both testis and epididymis indexes (P < 0.05) and lactate dehydrogenase levels (P < 0.01), as well as reduced serum LH and testosterone levels (P < 0.05). High levels of soybean isoflavones also increased malondialdehyde levels (P < 0.05), as well as increased the numbers of early and late apoptotic germ cells (P < 0.01) and the level of Bax proteins (P < 0.05) in the testis.

Conclusions

The results of this study indicate that consumption of soy isoflavones at dietary levels up to 250 ppm did not adversely affect reproductive parameters in Chinese mini-pig boars whereas higher levels of soy isoflavones may adversely affect male reproduction.     

Revealing the metabonomic variation of rosemary extracts using 1H NMR spectroscopy and multivariate data analysis

The molecular compositions of rosemary ( Rosmarinus officinalis L.) extracts and their dependence on extraction solvents, seasons, and drying processes were systematically characterized using NMR spectroscopy and multivariate data analysis. The results showed that the rosemary metabonome was dominated by 33 metabolites including sugars, amino acids, organic acids, polyphenolic acids, and diterpenes, among which quinate, cis-4-glucosyloxycinnamic acid, and 3,4,5-trimethoxyphenylmethanol were found in rosemary for the first time. Compared with water extracts, the 50% aqueous methanol extracts contained higher levels of sucrose, succinate, fumarate, malonate, shikimate, and phenolic acids, but lower levels of fructose, glucose, citrate, and quinate. Chloroform/methanol was an excellent solvent for selective extraction of diterpenes. From February to August, the levels of rosmarinate and quinate increased, whereas the sucrose level decreased. The sun-dried samples contained higher concentrations of rosmarinate, sucrose, and some amino acids but lower concentrations of glucose, fructose, malate, succinate, lactate, and quinate than freeze-dried ones. These findings will fill the gap in the understanding of rosemary composition and its variations.     

Results of molecular analysis of an archaeological hemp (<Emphasis Type="Italic">Cannabis sativa</Emphasis> L.) DNA sample from North West China

Hemp (Cannabis sativa L.) cultivation and utilization is an ancient practice to human civilization. There are some controversies on the origin and subsequent spread of this species. Ancient plant DNA has proven to be a powerful tool to solve phylogenetic problems. In this study, ancient DNA was extracted from an archaeological specimen of Cannabis sativa associated with archaeological human remains from China. Ribosomal and Cannabis specific chloroplast DNA regions were PCR amplified. Sequencing of a species-specific region and subsequent comparison with published sequences were performed. Successful amplification, sequencing and sequence comparison with published data suggested the presence of hemp specific DNA in the archeological specimen. The role of Humulus japonicus Sieb. et Zucc. in the evolution of Cannabis is also indicated. The identification of ancient DNA of 2500 years old C. sativa sample showed that C. sativa races might have been introduced into China from the European–Siberian center of diversity.     

Improvement of texture properties and flavor of frozen dough by carrot (Daucus carota) antifreeze protein supplementation

The effects of concentrated carrot protein (CCP) containing 15.4% (w/w) carrot (Daucus carota) antifreeze protein on texture properties of frozen dough and volatile compounds of crumb were studied. CCP supplementation lowered the freezable water content of the dough, resulting in some beneficial effects including holding loaf volume steadily and making the dough softer and steadier during frozen storage. Furthermore, SPME-GC-MS analysis showed CCP supplementation did not give any negative influences on volatile compounds of crumb and gave a pleasant aroma felt like Michelia alba DC from trans-caryophyllene simultaneously. Combining our previous results that CCP supplementation improves the fermentation capacity of the frozen dough, CCP could be used as a beneficial additive for frozen dough processing.     

豇豆荚螟危害损失率测定及防治指标研究

经３年试验的结果表明，豇豆产量损失率与百花虫量呈正相关，当百花虫量为５．２２头时，由于豇豆的自然补偿力，损失微小，达１０．６头以上时，产量损失与对照相比差异极其显著，药剂防治指为百花虫量６－８头，最佳施药期是盛花期，最佳施药次数为３次。     

On-line measurement of mercury in simulated flue gas

Total and elemental mercury (Hg) in simulated flue gas was measured on-line by a commercial Semtech^® Hg analyzer. This instrument is based on Zeeman modulated Atomic Absorption Spectrometry. Both a wet chemical solution and a dry physical pyrolysis converter were applied to reduce the Hg(II) in the gas before leading it to the detector. Results show that the Semtech^® analyzer is suitable for measuring elemental Hg even in the presence of 2500 ppm SO₂ and 500 ppm HCl. For the measurement of Hg(II), the wet method is suitable only at SO₂ concentrations <50 ppm. The dry thermal converter filled with crushed quartz chips together with a small amount of soda lime converts Hg(II) quantitatively at laboratory scale. This result is promising, since the trace gases delivered to the system, such as SO₂, and HCl are similar to those produced in coal burning and waste incineration processes. The limiting factor for such a converter is its comparatively short life time of performance, about 20 hours.     

图书馆从自动化向数字化跨越过程中馆员角色的变化

通过对图书馆从自动化时期向数字化时期跨越过程中图书馆各个部门职能的变化,探讨了图书馆员的角色变化,并对来自出版商竞争的影响进行了分析。     

Inoculation of soil by <Emphasis Type="Italic">Bacillus subtilis</Emphasis> Y-IVI improves plant growth and colonization of the rhizosphere and interior tissues of muskmelon (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.)

Laboratory tests and greenhouse experiments were carried out to investigate the abilities of Bacillus subtilis Y-IVI to promote plant growth and to colonize the rhizosphere and interior tissues of muskmelon. Laboratory tests showed that B. subtilis Y-IVI can produce indole acetic acid, siderophores, and ammonia. The inoculation of soil with green fluorescent protein-tagged Y-IVI (GY-IVI) significantly increased plant shoot and root dry weights as compared with the non-inoculated soils. The inoculation of soil with B. subtilis GY-IVI maintained approximately 10⁸ colony-forming units (cfu) of GY-IVI per gram of dry rhizosphere soil for 1 month. The GY-IVI recovered from the interior of crowns and roots in the inoculated soil were 10⁶ and 10⁷ cfu g⁻¹ dry weight, respectively, suggesting that GY-IVI acted as an endophyte. In the present study, we combined the two important growth promotion ingredients, colonization ability and growth promotion metabolites produced by biological agents, to investigate B. subtilis Y-IVI’s promotion effects on muskmelon growth.     

Determination of advanced glycation endproducts by LC-MS/MS in raw and roasted almonds (Prunus dulcis)

A sensitive and reliable LC-(ESI)MS/MS method was developed and validated for the simultaneous analysis of five common advanced glycation endproducts (AGEs) after enzymatic digestion in raw and roasted almonds. AGEs included carboxymethyl-lysine (CML), carboxyethyl-lysine (CEL), pyralline (Pyr), argpyrimidine (Arg-p), and pentosidine (Pento-s). This method allows accurate quantitation of free and AGE-protein adducts of target AGEs. Results indicate that CML and CEL are found in both raw and roasted almonds. Pyr was identified for the first time in roasted almonds and accounted for 64.4% of free plus bound measured AGEs. Arg-p and Pento-s were below the limit of detection in all almond samples tested. Free AGEs accounted for 1.3-26.8% of free plus bound measured AGEs, indicating that protein-bound forms predominate. The roasting process significantly increased CML, CEL, and Pyr formation, but no significant correlation was observed between these AGEs and roasting temperature.