Organics captured from comet 81P/Wild 2 by the Stardust spacecraft

Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples.     

新疆褐牛细管冻精改良当地蒙古牛效果分析

用新疆褐牛细管冻精为父本,以新疆博尔塔拉州本地蒙古牛为母本进行杂交,即采用人工授精的方法获得杂交F1。褐蒙F1,初生重公犊比蒙古牛提高28．26％,母犊提高27．23％,断奶重公犊提高92．04％,母犊提高92．16％。同龄褐蒙F1屠宰率、净肉率比本地蒙古牛提高6．6％和8％。平均每头褐蒙F1牛可增肉70．3kg,按每千克牛肉25元计算,增效1758元。细管冻精配种可降低成本130元。     

不同植物油对奶牛瘤胃液、血浆中脂肪酸及乳脂中共轭亚油酸组成的影响

为改善牛奶脂肪酸构成,提高乳脂中CLA含量,研究瘤胃液、血浆和乳脂中脂肪酸的代谢规律,探寻提高乳品质的合适途径,本试验以3头装有永久性瘤胃瘘管的经产荷斯坦奶牛为试验动物,采用3×3拉丁方设计,研究向日粮中添加不同植物油(即葵花油、亚麻油、菜籽油,3种日粮的粗脂肪含量基本相同)对奶牛瘤胃液、血浆中脂肪酸及乳脂中CLA的影响。结果表明:(1)日粮中添加3种不同植物油,葵花油组、亚麻油组乳脂中的CLA比例均显著高于菜籽油组(P<0.05),且以葵花油组最高;乳脂中PUFA的比例则是亚麻油组显著高于菜籽油组(P<0.05);(2)3组间血浆中C14∶0、C16∶0、C18∶0的比例差异不显著(P>0.05),菜籽油组C18∶1的比例显著高于亚麻油组和葵花油组(P<0.05),而后两组差异不显著(P>0.05),亚麻油组和葵花油组t11-C18∶1的比例与菜籽油组间差异均达到显著水平(P<0.05),亚麻油组和菜籽油组中C18∶2的比例差异显著(P<0.05);(3)采食添加不同植物油日粮后,瘤胃液中各种脂肪酸动态变化的平均值差异不显著(P>0.05)。总的趋势是随着时间的延长,饱和脂肪酸含量逐渐增加,而不饱和脂肪酸含量逐渐减少。瘤胃液中CLA的比例不同时间点均较低。由本研究可知,在优化奶牛乳脂肪酸构成提高CLA含量方面,以葵花油效果最好。     

Magnetoelectronics

An approach to electronics is emerging that is based on the up or down spin of the carriers rather than on electrons or holes as in traditional semiconductor electronics. The physical basis for the observed effects is presented, and the initial successful applications of this technology for information storage are reviewed. Additional opportunities for the exploitation of this technology, which are currently under study, are described.     

Vacuum Squeezing of Solids: Macroscopic Quantum States Driven by Light Pulses

Femtosecond laser pulses and coherent two-phonon Raman scattering were used to excite KTaO3 into a squeezed state, nearly periodic in time, in which the variance of the atomic displacements dips below the standard quantum limit for half of a cycle. This nonclassical state involves a continuum of transverse acoustic modes that leads to oscillations in the refractive index associated with the frequency of a van Hove singularity in the phonon density of states.     

Heat Shock Protein 70 and Sex Steroid Receptors in the Follicular Structures of Induced Ovarian Cysts

The purpose of this study was to estimate the expression and relative amounts of estrogen (ER) and progesterone receptors (PR) and their isoforms as well as heat shock protein 70 (HSP70) in ovaries of rats with induced cystic ovarian disease (COD). Primary, secondary, tertiary, atretic and cystic follicles were evaluated by immunohistochemistry and total ovarian proteins were analyzed by Western blot. In the granulosa layer, growing and cystic follicles in the treated group have a higher expression of ERα than growing follicles of control individuals. In the theca interna layer, tertiary follicles presented a significantly higher expression of ERα in the treated group. An increase in total ERα protein was detected in the treated group. Granulosa cells of all growing, atretic and cystic follicles show a lower expression of ERβ in animals with COD, and the total protein expression of ERβ was lower in this group. The expression of PR was lower in the granulosa cell layer of tertiary and cystic follicles in treated animals, and theca interna layer had less intense immunostaining in this group. Although there were no differences in the expression of PR-B by Western blotting, the expression of PR-A was higher and the expression of PR-C was smaller in the treated group. An intense HSP70 immunostaining was observed in the cells of cystic follicles. By Western blotting, higher protein expression of HSP70 was detected in the ovarian samples of the control group than those of the treated ones. Ovaries of animals with COD exhibited an altered steroid receptor expression and subtype balance as compared with control animals, and an increase in HSP70 immunoexpression.     

Comparison of two methods of detecting purulent vaginal discharge in postpartum dairy cows and effect of intrauterine cephapirin on reproductive performance

Objective   Part 1: compare the use of a Metricheck™ device (a stainless steel probe with a semi-spherical rubber cup attached at one end) to sample the contents of the anterior vagina with a vaginal speculum examination for the diagnosis of pus in the vagina of postpartum dairy cows and to investigate the association of that pus with reproductive performance. Part 2: assess the effect of a single intrauterine infusion of 500 mg cephapirin in cows diagnosed with vaginal purulent or mucopurulent discharge 7 to 28 days after calving on reproductive performance.
Procedure   Six herds were visited fortnightly to examine cows that had calved between 7 and 28 days (n = 423) with both the Metricheck device and a vaginal speculum to score, by each method, the vaginal discharge from 0 (clear or absent) to 3 (purulent) for each animal included in the study. Half of the cows that had a positive discharge score (1 to 3 by either examination method) were then treated with an intrauterine infusion of 500 mg of cephapirin. The relationship between Metricheck score, vaginoscopy score, treatment and reproductive performance was assessed.
Results   There was a substantial measure of agreement between each method when scores were analysed by status. Cows that were positive with either method had inferior reproductive performance compared with cows with a score of zero. Treatment of cows diagnosed with a purulent or mucopurulent discharge with intrauterine cephapirin improved reproductive performance in both the vaginoscopy and Metricheck groups.     

Bisphenol A disrupts granulosa cell function

Because of its widespread use and potential adverse biological effects, bisphenol A (BPA) represents one of the most studied endocrine-disrupting compounds. Within the reproductive system, ovarian granulosa cells have been documented as a target of BPA action, but no consensus has been reached about functional modifications induced by BPA. On these bases, we studied the potential disrupting effects of BPA on the main granulosa cell functional activities, also taking into account a potential interference with the ovarian angiogenic process. Ovarian granulosa cells were isolated from porcine follicles and cultured in the presence or absence of BPA at different concentrations for 48 h. Cell proliferation was studied by measuring adenosine triphosphate content. Progesterone (P4) and estradiol 17β (E2) production was determined by radioimmunoassay. Vascular endothelial growth factor (VEGF) output was quantified by an enzyme-linked immunosorbent assay. Redox status was monitored by measuring superoxide anion and hydrogen peroxide, and by determining the activities of the scavenging enzymes superoxide dismutase, catalase, and peroxidase by colorimetric methods. Granulosa cell proliferation as well as redox status resulted unaffected by BPA. Concentrations of E2 were stimulated by the lower BPA concentration, whereas they were inhibited by the larger doses tested. P4 output was decreased by all BPA concentrations. To the contrary, VEGF production was stimulated. Data indicate that BPA can interfere with reproductive activity by affecting granulosa cell steroidogenesis in vitro; furthermore, BPA can exert a promoting effect on the ovarian angiogenic process by increasing VEGF output in pigs. A disruption of this finely tuned process seems particularly relevant because of the risk of uncontrolled neovascularization.     

草莓新品种引种试验

对引进的74个国内外草莓新优品种进行栽培试验比较研究,筛选出鬼怒甘、公四莓、法兰地和麦特来4个优于主栽种丰香、适宜在我省推广栽培的品种。