Influence of Light and Photosynthesis on Alkaloid Concentration in Larkspur

Concentrations of toxic norditerpenoid alkaloids vary greatly in tall larkspur (Delphinium barbeyi) and may be influenced by environmental stress. We evaluated the effect of shade, darkness, and inhibition of photosynthesis on toxic alkaloid concentration. In plants treated with metribuzin to inhibit photosynthesis, alkaloid concentration increased, but dry weight of the plants decreased as growth ceased, leaving absolute alkaloid content similar to that of control plants. Short-term shade (70% reduction in sunlight for three days), dark treatments from leaves collected at night, and aluminum foil covered leaves all increased alkaloid concentration in comparison to untreated control plants. It appears that absolute amounts of alkaloids remained the same, but the mass of stressed plants declined as nonstructural carbohydrates were depleted, thus increasing the relative concentration of alkaloids. We conclude that norditerpenoid alkaloids in larkspur do not respond to short-term light stress. Alkaloid concentration was lower in larkspur plants growing beneath forest canopy and in potted plants in a long-term shade study (70% reduction in sun light for 21 days) than plants growing in open sunlight. Long-term shade may have reduced synthesis of norditerpenoid alkaloids, particularly in the earlier developmental stages of the plant. Shade stress or photosynthesis inhibition apparently did not increase norditerpenoid alkaloid synthesis, which contrasts with the carbon/nutrient balance theory of plant defense.     

TNFSF14-Derived Molecules as a Novel Treatment for Obesity and Type 2 Diabetes

Obesity is one of the most prevalent metabolic diseases in the Western world and correlates directly with glucose intolerance and insulin resistance, often culminating in Type 2 Diabetes (T2D). Importantly, our team has recently shown that the TNF superfamily (TNFSF) member protein, TNFSF14, has been reported to protect against high fat diet induced obesity and pre-diabetes. We hypothesized that mimics of TNFSF14 may therefore be valuable as anti-diabetic agents. In this study, we use in silico approaches to identify key regions of TNFSF14 responsible for binding to the Herpes virus entry mediator and Lymphotoxin β receptor. In vitro evaluation of a selection of optimised peptides identified six potentially therapeutic TNFSF14 peptides. We report that these peptides increased insulin and fatty acid oxidation signalling in skeletal muscle cells. We then selected one of these promising peptides to determine the efficacy to promote metabolic benefits in vivo. Importantly, the TNFSF14 peptide 7 reduced high fat diet-induced glucose intolerance, insulin resistance and hyperinsulinemia in a mouse model of obesity. In addition, we highlight that the TNFSF14 peptide 7 resulted in a marked reduction in liver steatosis and a concomitant increase in phospho-AMPK signalling. We conclude that TNFSF14-derived molecules positively regulate glucose homeostasis and lipid metabolism and may therefore open a completely novel therapeutic pathway for treating obesity and T2D.     

Mo-14Re钼铼合金高温压缩跨尺度本构模型建立

为研究Mo-14Re钼铼合金高温流变行为及其跨尺度表征,本研究采用Gleeble热模拟试验机对钼铼合金棒材进行了高温压缩试验,选取的温度为1400℃、1500℃、1600℃,应变速率为0.01 /s、0.1 /s、1 /s、10 /s。研究表明,高温和低应变率变形时,应变率敏感因子逐渐增大,材料塑性流动性能也就越好,且变形过程中应力硬化和软化两种现象同时存在。在此基础上,建立了跨尺度本构模型,流变应力表征考虑了与不动位错的阻力、热激活、晶界效应的微观剪切应力,微观组织演变考虑了晶粒尺寸、位错密度、动态再结晶率以及裂纹体积分数等微观组织演变。随后基于遗传算法确定了模型中的材料参数,屈服应力、晶粒尺寸和流变应力的模型计算值与试验结果吻合情况良好,可知该模型可以描述Mo-14Re钼铼合金在高温变形时流变行为及其微观组织演变。     

适合中原油田高温高盐油藏的胶态分散凝胶驱油技术及应用

在高温、高矿化度条件下, 使用低浓度AM/AMPS/AMC14S三元共聚物和复合有机交联剂, 制备了耐温抗盐的胶态分散凝胶体系。考查了聚合物类型、聚合物浓度、交联剂浓度、以及pH值对体系成胶粘度的影响。结果表明, 恒温90℃经90d老化实验后粘度仍保留在400mPa·s以上。使用该体系在中原油田进行了矿场先导试验, 增油降水效果明显。     

中国石油“十三五”物探技术进展及“十四五”发展方向思考

“十三五”期间,中国石油天然气股份有限公司(简称中国石油)根据日益复杂的油气勘探开发对象,分盆地、分领域制定物探技术政策,强化地震采集源头设计,严格过程管控,确保部署成效;开展老资料精细处理解释,挖掘资料潜力,瞄准生产瓶颈难题,强化科研攻关,提高解疑能力;强化分盆地、分领域技术研讨交流,加强物探地质复合型人才培养,提升人才素质和技术应用水平;强化基础工作,实施精益管理,促进有序稳健发展;发展完善了6类物探技术系列,形成19项关键技术,有力支撑了中国石油原油产量稳中有升、天然气业务快速发展。“十四五”油气勘探开发重心不断向深层—超深层、页岩油气,以及强复杂地表更复杂领域转移,提高难动用储量开发成效、提高老油气田采收率也面临技术挑战。为了满足新形势下油气勘探开发需求,针对八大重点领域,中国石油将按照集成推广、科研攻关、试验探索3个层次,发展高效、低成本、高精度物探技术,重点发展智能物探、深层地球物理勘探、油藏地球物理、井中地震等全新一代物探技术。     

Epitaxial growth and surface morphology of aluminum films deposited on mica studied by transmission electron microscopy and atomic force microscopy

The bulk structure and epitaxial growth of aluminum films deposited on mica substrates by thermal evaporation in a wide temperature range (16-550 °C) in high vacuum were investigated by transmission electron microscopy and transmission electron diffraction. The surface morphology of the films was observed and analyzed by atomic force microscopy. The films prepared at room temperature consist of single crystals having a diameter of 90 ± 40 nm with (111) planes. The surface of the films comprises spherical grains with morphology that is caused by self-shadowing during the deposition. The surface of the films becomes smoother as the temperature increases, and atomically-smooth surfaces with a root-mean-square roughness of about 0.45 nm over an area of 1 μm² are obtained at 250-350 °C. The crystals are oriented randomly along the [111] direction perpendicular to the substrate. The surface of the films consists of larger (> 300 nm) grains with terraces, and the surface becomes rough above 400 °C. Films with well-oriented single crystals along the [111] direction perpendicular to the substrate are obtained above 520 °C. The films grown epitaxially at 520-550 °C are characterized by the isolated grains with a diameter of 1220 ± 450 nm.     

14Cr1MoR+410S复合钢板焊接工艺探析

在详细分析焦炭塔14Cr1MoR+410S复合钢板焊接性的基础上,制订了合理的焊接工艺,并通过焊接工艺试验验证其正确性。这说明所制订的焊接工艺能有效防止裂纹,获得性能良好的焊接接头,从而确保了焦炭塔制造质量。     

夏商周断代工程中14C系列样品的树轮校正

对国外程序的适用性和计算的准确性进行了评价,并与自编程序进行了比较。计算结果表明,OxCal程序在夏商周断代工程中是可用的,但其所能计算的系列样品长度有一定限制。     

空气中~(14)C取样器

本文介绍了空气中14 C取样器的结构、性能 ,及取样器在中辐院使用运行一年的取样监测情况。该仪器可以在高达 6～ 8L/min的空气流量下工作 ,对空气中 CO2 的收集效率≥ 98%。对于 1 0 0 min计数时间 ,空气中14 C的探测下限为 0 .0 36Bq/m3