Antiplatelet effect of butylidenephthalide

Butylidenephthalide inhibited, in a dose-dependent manner, the aggregation and release reaction of washed rabbit platelets induced by collagen and arachidonic acid. Butylidenephthalide also inhibited slightly the platelet aggregation induced by PAF and ADP, but not that by thrombin or ionophore A23187. Thromboxane B2 formation caused by collagen, arachidonic acid, thrombin and ionophore A23187 was in each case markedly inhibited by butylidenephthalide. Butylidenephthalide inhibited the aggregation of ADP-refractory platelets, thrombin-degranulated platelets, chymotrypsin-treated platelets and platelets in the presence of creatine phosphate/creatine phosphokinase. Its inhibition of collagen-induced aggregation was more marked at lower Ca2+ concentrations in the medium. The aggregability of platelets inhibited by butylidenephthalide could be recovered after the washing of platelets. In human platelet-rich plasma, butylidenephthalide and indomethacin prevented the secondary aggregation and blocked ATP release from platelets induced by epinephrine. Prostaglandin E2 formed by the incubation of guinea-pig lung homogenate with arachidonic acid could be inhibited by butylidenephthalide, indomethacin and aspirin. It is concluded that the antiplatelet effect of butylidenephthalide is mainly due to an inhibitory effect on cyclo-oxygenase and may be due partly to interference with calcium mobilization.     

Climatic variability,hydrologic anomaly,and methane emission can turn productive freshwater marshes into net carbon sources

Freshwater marshes are well‐known for their ecological functions in carbon sequestration, but complete carbon budgets that include both methane (CH₄) and lateral carbon fluxes for these ecosystems are rarely available. To the best of our knowledge, this is the first full carbon balance for a freshwater marsh where vertical gaseous [carbon dioxide (CO₂) and CH₄] and lateral hydrologic fluxes (dissolved and particulate organic carbon) have been simultaneously measured for multiple years (2011–2013). Carbon accumulation in the sediments suggested that the marsh was a long‐term carbon sink and accumulated ~96.9 ± 10.3 (±95% CI) g C m^?2 yr^?1 during the last ~50 years. However, abnormal climate conditions in the last 3 years turned the marsh to a source of carbon (42.7 ± 23.4 g C m^?2 yr^?1). Gross ecosystem production and ecosystem respiration were the two largest fluxes in the annual carbon budget. Yet, these two fluxes compensated each other to a large extent and led to the marsh being a CO₂ sink in 2011 (?78.8 ± 33.6 g C m^?2 yr^?1), near CO₂‐neutral in 2012 (29.7 ± 37.2 g C m^?2 yr^?1), and a CO₂ source in 2013 (92.9 ± 28.0 g C m^?2 yr^?1). The CH₄ emission was consistently high with a three‐year average of 50.8 ± 1.0 g C m^?2 yr^?1. Considerable hydrologic carbon flowed laterally both into and out of the marsh (108.3 ± 5.4 and 86.2 ± 10.5 g C m^?2 yr^?1, respectively). In total, hydrologic carbon fluxes contributed ~23 ± 13 g C m^?2 yr^?1 to the three‐year carbon budget. Our findings highlight the importance of lateral hydrologic inflows/outflows in wetland carbon budgets, especially in those characterized by a flow‐through hydrologic regime. In addition, different carbon fluxes responded unequally to climate variability/anomalies and, thus, the total carbon budgets may vary drastically among years.     

A population-based twin study on sleep duration and body composition

The aim of this study is to investigate the relationship between sleep duration and body composition and to estimate the genetic contribution of sleep duration and body composition in a Chinese twin population. This cross-sectional analysis included 738 men and 511 women aged 21-72 year. Anthropometric and dual-energy X-ray absorptiometry (DXA) measures of body composition were used. Sleep duration was obtained from a standard sleep questionnaire. Multiple regression models were used to examine the association between sleep duration and body composition measures. Structural equation modeling was used to assess the heritability of sleep duration and body composition. Compared with individuals in the 2nd and 3rd age-specific quartiles of sleep duration (reference group), shorter (1st quartile) sleep duration among women but not men was associated with higher z-scores (0.248-0.317) for all adiposity measures--BMI, fat mass index (FMI), percent body fat mass (%BF), and percent trunk fat mass (%TF), P < 0.05 for each--and with 0.306 lower z-scores for percent body lean mass (%LM) and 0.353 lower lean/fat mass ratio (LFR), P < 0.01 for each. The heritability of sleep duration was 0.27 in men and 0.29 in women, while the heritability of body composition was as high as 0.56-0.73 after adjustment for age in both genders. Short sleep duration was associated with increased body fat and decreased lean body mass in women but not in men. Sleep duration was largely influenced by environmental factors while adiposity measures were mainly influenced by genetic factors.     

猪生产激素基因在巴斯德毕赤酵母中的高效分泌表达及产物的N—糖基化分析

利用含有强启动子PAOX1和α-MF信号肽序列的巴斯德毕赤酵母载体质粒pPICZαA构建出含PST基因的重复组质粒pPICZαA－pST。通过电击将经SacI酶后线化的pPICZαA－pST质粒转化到巴斯德毕赤酵母X－33菌中,并筛选Mut^ 表型的重型的生组菌。表达产物的SDS－PAGE和Western blot结果表明,分泌于胞外的PST蛋白分子量比天然PST分子量稍大,而胞内的PST蛋白分子量与天然PST大小相同,将经SacI酶切后线性化的pPICZαA－pST再次转化重组酵母细胞X－33／pPICZαA－pST(Mut^ ）,所得表达产物的SDS－PAGE和Western blot结果显示,PST基因的表达水平明显提高,且表达产生的蛋白均可发生正确的抗原－抗体结合反应,表达量达956mg/L。将发酵液上清进行N－糖基化分析,显示rPST无N－糖基化加工修饰。     

普通小麦与鸭茅状摩擦禾的远缘杂交──Ⅰ．胚形成频率

本文在国内首次报道普通小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ,２ｎ＝６ｘ＝４２）和鸭茅状摩擦禾（Ｔｒｉｐｓａｃｕｍｄａｃｔｙｌｏｉｄｅｓ,２ｎ＝４ｘ＝７２）杂交成功。用３３个春小麦品种（系）为母本,与鸭茅状摩擦禾杂交,授粉６６３６朵花,获得３０８３个颖果。颖果分为有胚和无胚两类。有胚颖果８０６个,占总颖果数的２６．１４％。３３个母本中３０个都能和鸭茅状摩擦禾杂交,１４个母本的杂交亲和性（胚数／授粉花数×１００）超过１０％。４个最高的分别达到５９．００％,３９．００％,２９．５０％和２２．６６％与小麦和玉米（Ｚｅａｍａｙｓ,２ｎ＝２ｘ＝２０）的杂交相比,鸭茅状摩擦禾同样对小麦Ｋｒ基因的作用不敏感,且与小麦的杂交亲和性要比与玉米杂交时高。加之鸭茅状摩擦禾为野生型,具有多年生、多分枝、花期长等特点,可以克服小麦和玉米杂交时花期不遇的困难。讨论了用它作为花粉给体的优越性及在小麦改良和产生小麦单倍体上的前景。     

Carbon Balance in an Alpine Steppe in the Qinghai-Tibet Plateau

Carbon fluxes were measured using a static chamber technique in an alpine steppe in the Qinghai-Tibet Plateau from July 2000 to July 200t. It was shown that carbon emissions decreased in autumn and increased in spring of the next year, with higher values in growth seasons than in winters. An exponential correlation (Ecarbon = 0.22(exp(0.09T) + In(0.31P + 1)), R2 = 0.77, P < 0.001) was shown between carbon emissions and environmental factors such as temperature (T) and precipitation (P). Using the daily temperature (T) and total precipitation (R), annual carbon emission from soil to the atmosphere was estimated to be 79.6 g C/m2, 46% of which was emitted by microbial respiration. Considering an average net primary production of 92.5 g C/m2 per year within the 2 year experiment, alpine steppes can take up 55.9 g CO2-C/m2 per year. This indicates that alpine steppes are a distinct carbon sink, although this carbon reservoir was quite small.     

Correction: Talin tension sensor reveals novel features of focal adhesion force transmission and mechanosensitivity

The precise architecture of hair bundles, the arrays of mechanosensitive microvilli-like stereocilia crowning the auditory hair cells, is essential to hearing. Myosin IIIa, defective in the late-onset deafness form DFNB30, has been proposed to transport espin-1 to the tips of stereocilia, thereby promoting their elongation. We show that Myo3a^−/−Myo3b^−/− mice lacking myosin IIIa and myosin IIIb are profoundly deaf, whereas Myo3a-cKO Myo3b^−/− mice lacking myosin IIIb and losing myosin IIIa postnatally have normal hearing. Myo3a^−/−Myo3b^−/− cochlear hair bundles display robust mechanoelectrical transduction currents with normal kinetics but show severe embryonic abnormalities whose features rapidly change. These include abnormally tall and numerous microvilli or stereocilia, ungraded stereocilia bundles, and bundle rounding and closure. Surprisingly, espin-1 is properly targeted to Myo3a^−/−Myo3b^−/− stereocilia tips. Our results uncover the critical role that class III myosins play redundantly in hair-bundle morphogenesis; they unexpectedly limit the elongation of stereocilia and of subsequently regressing microvilli, thus contributing to the early hair bundle shaping.     

Comparison of photobioreactors for cultivation of Undaria pinnatifida gametophytes

Undaria pinnatifida gametophytes were grown in 2.5 l bubble column and airlift reactor at 25 °C and light intensity of 40 mol m^–2 s^–1 for 6 days. With aeration at 1 l min^–1, the airlift reactor yielded higher growth rate (0.12 mg DW ml^–1 d^–1) than a bubble column (0.08 mg DW ml^–1 d^–1). The advantages were related to the more homogeneous fluid dynamic characteristics of the airlift reactor.     

协青早B//协青早B/东乡野生稻BC1F9群体低磷耐性鉴定及其生理机制

通过水培法对协青早B∥协青早B/东乡野生稻BC1F9群体221个株系低磷耐性进行了鉴定,测定了株高、叶龄、黄叶数、地上部干物质量等形态指标及丙二醛(MDA)、可溶性糖和地上部磷含量等生理指标,计算了磷效率,并对各指标间相关性进行了分析.结果表明:221个株系的7个指标均显示出差异性,耐性株系在低磷胁迫下表现为相对叶龄、相对株高、相对地上部干物质量和相对可溶性糖含量较高,相对黄叶数和相对MDA含量较低,相对地上部磷含量差异不明显;磷效率与磷利用效率和磷吸收效率均呈正相关,其中磷利用效率与磷效率达到极显著水平(P＜0.01),表明东乡野生稻回交重组自交系中耐性株系低磷耐性原因主要是具有高磷利用效率,即其单位吸磷量干物质合成力较高.