核受体Rev-erbs的能量稳态调控作用及其运动科学研究展望

 核受体Rev-erbs是能量稳态调控的核心转录调节因子,其表达受饮食、药物、运动等因素的影响;Rev-erbs参与糖脂代谢、胰岛素分泌、血糖稳态调节等多个生物学过程,是肥胖症、糖尿病等慢性代谢性疾病治疗的重要药物靶标,通过调节糖脂代谢通路中的靶分子,调控组织的能量稳态。运动干预刺激肝脏、骨骼肌等组织中Rev-erbs表达,调控糖脂代谢基因,维持细胞能量稳态,可能是慢性病运动干预的重要适应机制。简述了Rev-erbs的结构特点、表达调控因素与作用机制,分析了运动干预对Rev-erbs表达的影响与代谢调控机制,以及Rev-erbs在运动科学领域的国际前沿和发展趋势。     

Adipocytes as regulators of energy balance and glucose homeostasis

Adipocytes have been studied with increasing intensity as a result of the emergence of obesity as a serious public health problem and the realization that adipose tissue serves as an integrator of various physiological pathways. In particular, their role in calorie storage makes adipocytes well suited to the regulation of energy balance. Adipose tissue also serves as a crucial integrator of glucose homeostasis. Knowledge of adipocyte biology is therefore crucial for understanding the pathophysiological basis of obesity and metabolic diseases such as type 2 diabetes. Furthermore, the rational manipulation of adipose physiology is a promising avenue for therapy of these conditions.     

Microenvironmental regulation of stem cells in intestinal homeostasis and cancer

The identification of intestinal stem cells as well as their malignant counterparts, colon cancer stem cells, has undergone rapid development in recent years. Under physiological conditions, intestinal homeostasis is a carefully balanced and efficient interplay between stem cells, their progeny and the microenvironment. These interactions regulate the astonishingly rapid renewal of the intestinal epithelial layer, which consequently puts us at serious risk of developing cancer. Here we highlight the microenvironment-derived signals that regulate stem-cell fate and epithelial differentiation. As our understanding of normal intestinal crypt homeostasis grows, these developments may point towards new insights into the origin of cancer and the maintenance and regulation of cancer stem cells.     

IRS-2 pathways integrate female reproduction and energy homeostasis

Severe dietary restriction, catabolic states and even short-term caloric deprivation impair fertility in mammals. Likewise, obesity is associated with infertile conditions such as polycystic ovary syndrome. The reproductive status of lower organisms such as Caenorhabditis elegans is also modulated by availability of nutrients. Thus, fertility requires the integration of reproductive and metabolic signals. Here we show that deletion of insulin receptor substrate-2 (IRS-2), a component of the insulin/insulin-like growth factor-1 signalling cascade, causes female infertility. Mice lacking IRS-2 have small, anovulatory ovaries with reduced numbers of follicles. Plasma concentrations of luteinizing hormone, prolactin and sex steroids are low in these animals. Pituitaries are decreased in size and contain reduced numbers of gonadotrophs. Females lacking IRS-2 have increased food intake and obesity, despite elevated levels of leptin. Our findings indicate that insulin, together with leptin and other neuropeptides, may modulate hypothalamic control of appetite and reproductive endocrinology. Coupled with findings on the role of insulin-signalling pathways in the regulation of fertility, metabolism and longevity in C. elegans and Drosophila, we have identified an evolutionarily conserved mechanism in mammals that regulates both reproduction and energy homeostasis.     

黄腐酸对大豆内源激素的调控及结瘤能力的影响

为探讨黄腐酸提高大豆结瘤能力的作用机理,以辽宁慢生根瘤菌(Bradyrhizobium liaoningense)CCBAU 05525和冀豆17为材料,采用高效液相色谱法(HPLC)探究黄腐酸对大豆结瘤初期内源激素含量、分布及结瘤的影响.结果表明:黄腐酸质量浓度为500 mg/L时大豆结瘤数量最多,比对照组显著提高73.1%,同时该条件下激素含量和分布变化最为明显,具体表现为大豆根、茎、叶中玉米素(ZT)、生长素(IAA)、赤霉素(GA3)含量增加,根中脱落酸(ABA)含量减少,叶中ABA含量增加.而黄腐酸质量浓度为1 000 mg/L时则表现为抑制大豆结瘤. 上述结果为解析黄腐酸提高大豆结瘤固氮的机理、增加大豆产量提供了理论依据.     

AMPK regulates NADPH homeostasis to promote tumour cell survival during energy stress

Overcoming metabolic stress is a critical step for solid tumour growth. However, the underlying mechanisms of cell death and survival under metabolic stress are not well understood. A key signalling pathway involved in metabolic adaptation is the liver kinase B1 (LKB1)-AMP-activated protein kinase (AMPK) pathway. Energy stress conditions that decrease intracellular ATP levels below a certain level promote AMPK activation by LKB1. Previous studies showed that LKB1-deficient or AMPK-deficient cells are resistant to oncogenic transformation and tumorigenesis, possibly because of the function of AMPK in metabolic adaptation. However, the mechanisms by which AMPK promotes metabolic adaptation in tumour cells are not fully understood. Here we show that AMPK activation, during energy stress, prolongs cell survival by redox regulation. Under these conditions, NADPH generation by the pentose phosphate pathway is impaired, but AMPK induces alternative routes to maintain NADPH and inhibit cell death. The inhibition of the acetyl-CoA carboxylases ACC1 and ACC2 by AMPK maintains NADPH levels by decreasing NADPH consumption in fatty-acid synthesis and increasing NADPH generation by means of fatty-acid oxidation. Knockdown of either ACC1 or ACC2 compensates for AMPK activation and facilitates anchorage-independent growth and solid tumour formation in vivo, whereas the activation of ACC1 or ACC2 attenuates these processes. Thus AMPK, in addition to its function in ATP homeostasis, has a key function in NADPH maintenance, which is critical for cancer cell survival under energy stress conditions, such as glucose limitations, anchorage-independent growth and solid tumour formation in vivo.     

双供电路灯调光节能技术研究

介绍了一种基于太阳能和市网供电相结合的双电源供电的调光节能技术,采用SPWM控制方式和新型桥式整流逆变电路,可按照环境和用户需要自动调节汞灯的发光强度,具有节能效果明显、输入电流的死区范围小、起辉时间短、发光效率高等特点。     

一种新型制冷机能量调节的控制算法

研究新型混合吸收式制冷循环的能量调节的自动控制问题.采用动态矩阵预测控制算法设计多变量动态矩阵控制器,对新型混合吸收式制冷循环的能量进行自动调节,同时利用软件Matlab/Simulink对其进行仿真,结果表明该算法能有效地改善控制器的动态特性,显著提高制冷机的抗干扰性,表现出了较好的自适应能力.     

利用发送速率调节无线传感器网络节点的能耗策略研究

无线传感器网络一般都采用节点逐跳转发方式进行数据传输,这一通信机制容易导致网络局部区域的节点能量消耗较快,进而导致整个网络过早死亡。根据无线传感器网络的数据传输特点建立了一种以节点跳数为基础的全新网络模型,通过分析网络的数据特征得到了节点承载的数据量模型,进而得出了传感器网络的能耗及其数据发送延迟。在此基础上,在保证应用延迟需求前提下,提出了网络寿命最大化的求解算法。这一算法通过依次降低能耗较高节点的数据发送速率来降低其能耗,同时通过升高能耗较低节点的数据传输率,最终取得最高效率的网络参数。通过理论分析、模拟实验结果及与其他算法效果的比较,文章所提出的解决法案可在很大程度上有效延长网络寿命。     

时滞反馈控制模型在能源消费系统中的应用

根据东部能源消费和西部能源输出之间相互支持、相互制约的复杂关系以及能源供需的时滞性建立了东西联动能源消费系统的时滞反馈控制模型,利用动力学的稳定性理论对这个能源供需模型进行了分析,并给出了东西部能源供需稳定的条件．通过对江苏省2000～2004年能源供需现状的分析,进一步验证了模型在一定程度上反映了我国能源供需的实际,对我国能源政策的制定具有重要的指导意义．     

论共生系统:肠道菌群和人类健康

共生是生物界中普遍存在的一种现象,互利共生的一个典型例子就是人类和肠道菌群.人类利用肠道菌群消化食物来获得生存所需的能量和营养,而肠道菌群则获得栖息地和营养.肠道菌群与人类相互作用形成了一种与人类健康密切相关的平衡状态,打破这种平衡状态会导致人体内的许多疾病,如肥胖、高血压、炎症性肠病、癌症等.肠道菌群参与宿主新陈代谢、机体免疫、基因表达、疾病发展和药物疗效,同时它也受饮食、抗生素、生活方式、遗传和时间点的影响.作者系统地回顾了人类与肠道菌群之间的相互作用,分析了肠道菌群在人类疾病治疗中的应用现状,描述了治疗中存在的主要问题,为肠道菌群在人类疾病治疗中的应用提供了新的思路.     

考虑风电反调峰特性的储能调峰优化策略

为解决风力发电并网的不确定性导致的电力系统调峰困难问题,提高新能源综合利用率,在深入分析储能调峰原理的基础上提出一种考虑风电调峰特性的储能调峰优化策略.首先介绍风电反调峰特性影响,根据调峰特性确定最低移峰功率和最高填谷功率,接着再综合考虑系统功率平衡约束、储能系统约束和电源测约束的基础上增加调峰可靠性约束,建立以负荷方差最小为目标的系统优化模型,最后构建计及调峰可靠性的评价指标.以某电网阶段时间内负荷数据为基础进行算例分析,对比恒功率策略,仿真结果验证本文方法调峰效果更优.     

家白蚁消化系统发育与取食行为的分析

通过解剖家白蚁幼蚁、工蚁、兵蚁和若蚁的消化系统及测量其消化道的大小与消化道内半固体褐色物质的含量，分析了家白蚁消化系统的发育和取食行为以及相互之间的关系，结果表明幼蚁消化道的分化不明显，主要通过交哺行为自工蚁处获得液体食物；兵蚁后肠囊的发育不很充分，也主要是通过交哺行为获得液体食物，其中夹杂有一定的半固体褐色物质；若蚁的后肠囊还有待进一步发育，所获得的食物既有液体食物也有半固体褐色食物；成年工蚁的后肠囊相当发达，基本上被半固体褐色物质完全填充，主要是依靠自我取食的纤维素物质而生存。     

Multiple intracellular signallings involved in regulation of on channels by GH releasing or inhibitory hormones in pituitary somatotropes

Influx of Ca2-via Ca2+ channels is the major step triggering exocytosis of pituitary somatotropes to release growth hormone (GH). Voltage-gated Ca2+ and K+ channels, the primary determinants of the influx of Ca2+ in somatotropes, are regulated by GH-releasing hornone (GHRH) and somatostatin (SRIF) through G protein-coupled signalling systems. Using whole-cell patch-clamp techniques, the changes of the Ca2+ and K+ currents in primary cultured somatotropes were recorded and signalling systems were studied using pharmacological reagents and intracellular dialysis of non-permeable molecules including antibodies and antisense oligonucleotides. GHRH increased both L-and T-types Ca2+ currents and decreased transient (I4) and delayed rectified (Ik) K+ currents. The increase in Ca2+ currents by GHRH was mediated by cAMP/protein kinase A system but the decrease in K+ currents required normal function of protein kinase C system. The GHRH-induced alteration of Ca2+ and K+ currents augments the influx of Ca2+ , leading to an increase in the [ Ca2+ ]I and the GH secretion. In contrary, a significant reduction in Ca2+ currents and increase in K currents were obtained in response to SRIF. The ion channel response to SRIF was demonstrated as a membrane delimited pathway and can be recorded by classic whole-cell configuration, Intracellular dialysis of anti-αi3 antibodies attenuated the increase in K + currents by SRIF whereas anti-αo antibodies blocked the reduction in the Ca2+ current by SRIF. Dialysis of antisense oligonucleotides specific for αo2 sub-units also attenuated the inhibition of SRIF on the Ca2+current. The Gi3 protein mediated the increase in K + currents and the Go2 protein mediated the reduction in the Ca2 +current by SRIF. The SRIF-induced alteration of Ca2 + and K + currents diminished the influx of Ca2+ , leading to a decrease in the [ Ca2+ ]I and the GH secretion. It is therefore concluded that multiple signalling systems are employed in the ion channel response to GHRH or SRIF in somatotropes, which leads to an increase or decrease in the GH secretion.     

Gut microbiota composition correlates with diet and health in the elderly

Alterations in intestinal microbiota composition are associated with several chronic conditions, including obesity and inflammatory diseases. The microbiota of older people displays greater inter-individual variation than that of younger adults. Here we show that the faecal microbiota composition from 178 elderly subjects formed groups, correlating with residence location in the community, day-hospital, rehabilitation or in long-term residential care. However, clustering of subjects by diet separated them by the same residence location and microbiota groupings. The separation of microbiota composition significantly correlated with measures of frailty, co-morbidity, nutritional status, markers of inflammation and with metabolites in faecal water. The individual microbiota of people in long-stay care was significantly less diverse than that of community dwellers. Loss of community-associated microbiota correlated with increased frailty. Collectively, the data support a relationship between diet, microbiota and health status, and indicate a role for diet-driven microbiota alterations in varying rates of health decline upon ageing.