几种常见中成药中有机磷农药残留检测分析

[目的] 建立几种中成药中有机磷农药残留量的测定方法.[方法]采用气相色谱法(GC法),氢火焰离子化(FID)检测器,对精致银翘解毒片?桑菊感冒片?羚羊感冒片?通宣理肺片?清瘟解毒片等几种中成药中有机磷类农药的残留量进行测定.[结果]5种中成药中未检出有机磷农药残留,平均回收率在63.3%~79.7%之间,RSD在5.2%~12.5%之间.[结论]5种中成药中有机磷农药残留未见检出,说明中成药中一般不含有机磷类农药或者含量极低,因此为安全?放心的使用中成药提供了科学依据,并且为检测中成药中有机磷农药残留提供了可行的测定方法.     

Temporal control of glucocorticoid neurodynamics and its relevance for brain homeostasis,neuropathology and glucocorticoid-based therapeutics

Glucocorticoids mediate plethora of actions throughout the human body. Within the brain, they modulate aspects of immune system and neuroinflammatory processes, interfere with cellular metabolism and viability, interact with systems of neurotransmission and regulate neural rhythms. The influence of glucocorticoids on memory and emotional behaviour is well known and there is increasing evidence for their involvement in many neuropsychiatric pathologies. These effects, which at times can be in opposing directions, depend not only on the concentration of glucocorticoids but also the duration of their presence, the temporal relationship between their fluctuations, the co-influence of other stimuli, and the overall state of brain activity. Moreover, they are region- and cell type-specific. The molecular basis of such diversity of effects lies on the orchestration of the spatiotemporal interplay between glucocorticoid- and mineralocorticoid receptors, and is achieved through complex dynamics, mainly mediated via the circadian and ultradian pattern of glucocorticoid secretion. More sophisticated methodologies are therefore required to better approach the study of these hormones and improve the effectiveness of glucocorticoid-based therapeutics.     

Sex differences in circadian timing systems: Implications for disease

Virtually every eukaryotic cell has an endogenous circadian clock and a biological sex. These cell-based clocks have been conceptualized as oscillators whose phase can be reset by internal signals such as hormones, and external cues such as light. The present review highlights the inter-relationship between circadian clocks and sex differences. In mammals, the suprachiasmatic nucleus (SCN) serves as a master clock synchronizing the phase of clocks throughout the body. Gonadal steroid receptors are expressed in almost every site that receives direct SCN input. Here we review sex differences in the circadian timing system in the hypothalamic–pituitary–gonadal axis (HPG), the hypothalamic–adrenal–pituitary (HPA) axis, and sleep–arousal systems. We also point to ways in which disruption of circadian rhythms within these systems differs in the sexes and is associated with dysfunction and disease. Understanding sex differentiated circadian timing systems can lead to improved treatment strategies for these conditions.     

Electrooxidation of quercetin at glassy carbon electrode studied by a.c. impedance spectroscopy

The present paper reports cyclic voltammetry and a.c. impedance spectroscopy studies on adsorption and electrooxidation of quercetin (3,3′,4′,5,7-pentahydroxyflavone) compound at glassy carbon electrode surface in 0.1 M sodium acetate–acetic acid buffer in 90% methanol solution. The resulted information provided support for a cascade electrooxidation mechanism, which process commences with oxidation of catechol hydroxyl groups and involves strongly adsorbed reaction intermediate. The significance of each oxidation step is explained through associated charge-transfer resistance (derived for all individual oxidation steps and electrosorption of quercetin) and capacitance parameters. This work also presents an original way to regenerate the surface of glassy carbon electrode (after being blocked by quercetin oxidation products) through voltammetric cycling over the potential range negative to the hydrogen reversible potential. The above is realized by means of in situ evolved hydrogen, which species is capable of electrochemically reducing products formed during the cascade electrooxidation reaction of quercetin.     

Multiple compartments with different metabolic characteristics are involved in biosynthesis of intracellular and released glutamine and citrate in astrocytes

The metabolism of glucose and lactate was investigated in cultured mouse cerebellar astrocytes, a culture preparation consisting of a homogeneous population of cells, by incubating the cells in a medium containing either [U-(13)C]glucose or [U-(13)C]lactate in combination with unlabeled lactate and glucose, respectively. After the incubation, cell extracts and media were analyzed by GC/MS (gas chromatography/mass spectrometry) for labeling patterns in aspartate, glutamate, and glutamine, as well as the tricarboxylic acid (TCA) cycle constituents citrate and fumarate. Triple labeling of extracellular citrate exceeded that of double labeling from [U-(13)C]glucose. This was not the case when lactate was the labeled precursor. These results indicate that pyruvate carboxylation in biosynthesis of releasable citrate was less prominent from lactate compared with glucose. As observed in the case of extracellular citrate, triple labeling of intracellular aspartate was higher than double labeling when [U-(13)C]glucose was the precursor, but not with [U-(13)C]lactate as precursor. The pattern of labeling in citrate was different intra- and extracellularly and the extent of labeling extracellularly was 10 times higher using [U-(13)C]glucose compared with [U-(13)C]lactate. However, the intracellular citrate labeling from [U-(13)C]glucose only exceeded that originating from labeled lactate by a factor of two. This is in contrast to the labeling pattern obtained for glutamine, since intracellularly this was equally prominent using [U-(13)C]glucose and [U-(13)C]lactate as substrates. Moreover, extracellularly the labeling was only slightly higher when using [U-(13)C]glucose compared with [U-(13)C]lactate. Intracellular glutamate and extracellular glutamine exhibited similar incorporation patterns with regard to double compared with triple labeling and the extent of incorporation of label from [U-(13)C]lactate compared with [U-(13)C]glucose. It should be noted that the main intracellular pools of citrate and glutamine were compartmentalized; i.e., releasable citrate and glutamine exhibited a labeling pattern distinctly different from that of their intracellular pools. Moreover, carboxylation of pyruvate using glucose as the precursor was more important for biosynthesis of releasable glutamine and citrate, compared with their intracellular pools. Based on the results a model of multiple compartments is suggested. The compartments differ with regard to utilization of lactate and glucose, synthetic pathways for TCA cycle intermediates and amino acids, particularly citrate and glutamine, as well as the contents of different metabolites.     

GC-MS分析苦豆子总碱中的13种生物碱

目的 定性、定量分析苦豆子中的生物碱.方法 采用732强酸性阳离子交换树脂法、Hydromatrix为基质的固相萃取法和有机溶剂液液萃取法制备新疆苦豆子总碱,并用GC-MS法分析总碱中生物碱的组分及相对含量.结果 3种方法提取的苦豆子总碱中各生物碱单体的组分类型相同;GC-MS法共检出13种生物碱,主要为槐定碱、槐果碱、苦参碱、异槐果碱、野啶碱、Lamprolobine和槐胺碱,占13种生物碱的相对百分含量分别为32.63%、19.99%、12.52%、9.25%、8.47%、6.16%、4.11%.结论 GC-MS法能够快速准确地检测苦豆子中槐定碱、苦参碱等多种生物碱成分.     

GC法测定维生素E原料中的有关物质

建立GC法检查维生素E中的有关物质。采用GC法测定,色谱条件为：采用HP-1毛细管柱为色谱柱（30m×0.32mm,0.25μm）,柱温265℃;检测器为氢火焰离子化检测器（FID）,检测器温度为275℃;进样口温度为275℃。维生素E检测限为7.98ng。本法简便、准确、灵敏度高,适用于维生素E中有关物质的测定。     

气相色谱法测定二丁基羟基甲苯的含量

目的建立二丁基羟基甲苯含量测定方法。方法采用气相色谱法,以4-叔丁酚为内标,色谱柱为DB-624毛细管柱（30m×0．53mm×1μm）,汽化室温度220℃,柱温180℃。载气：氮气,5mL·min^-1;检测室温度240℃,尾吹30mL·min^-1。进样量1μL。结果在0．041mg·mL^-1～1．01mg·mL^-1的范围内浓度（C）与峰面积相对响应值（f=A／A内）有良好的线性关系,r=0．9999;样品重复测定的RSD％为1．3％（n=6）,日间精密度RSD％为1．2％（n=4）;方法的检测限为1．2μg。结论气相色谱法可以控制二丁基羟基甲苯的含量。     

Behavioral and hormonal regulation of expression of the clock protein,PER2, in the central extended amygdala

PER2, a key molecular component of the mammalian circadian clock, is expressed rhythmically in many brain areas and peripheral tissues in mammals. Here we review findings from our work on the nature and regulation of rhythms of expression of PER2 in two anatomically and neurochemically defined subregions of the central extended amygdala, the oval nucleus of the bed nucleus of the stria terminalis (BNSTov) and the central nucleus of the amygdala (CEA). Daily rhythms in the expression of PER2 in these regions are coupled to those of the master circadian pacemaker, the suprachiasmatic nucleus (SCN) but, importantly, they are sensitive to homeostatic perturbations and to hormonal states that directly influence motivated behavior.