Phenological stages of the quince tree (Cydonia oblonga)

As in other temperate species, the quince tree (Cydonia oblonga) shows different phenological stages throughout its vegetative growth period in response to changing temperatures. Two cultivars were studied, and 15 phenological stages were identified during their annual cycle, starting at bud dormancy and ending at leaf fall a year later. The different phenological stages were classified according to the BBCH General Scale and Fleckinger's code. The length of all the stages was measured in days and as cumulative day degrees. This study of the quince tree might aid to prevent and deal with any potential physiological and pathological disorders.     

Topological analysis of the complex formed between neurokinin A and the NK2 tachykinin receptor

Neurokinin A stimulates physiological responses in the peripheral and central nervous systems upon interacting primarily with the tachykinin NK2 receptor (NK2R). In this study, the structure of NKA bound to the NK2R is characterised by use of fluorescence resonance energy transfer. Four fluorescent NKA analogues with Texas red introduced at amino acid positions 1, 4, 7 and 10 were prepared. When bound to a NK2R carrying enhanced green fluorescent protein at the N-terminus, all peptides reduce green fluorescent protein fluorescence from 10% to 50% due to energy transfer. The derived donor-acceptor distances are 46, 55, 59 and 69 A for the fluorophore linked to positions 1-10, respectively. The monotonic increase in distance clearly indicates that the peptide adopts an extended structure when bound to its receptor. The present data are used, in combination with rhodopsin structure, fluorescence studies, photoaffinity labelling and site-directed mutagenesis data to design a computer model of the NKA-NK2R complex. We propose that the N-terminus of NKA is exposed and accessible to the extracellular medium. Subsequent amino acids of the NKA peptide become progressively more buried residues up to approximately one-third of the transmembrane-spanning domain.     

Modelling of predator–prey trophic interactions. Part II: Three trophic levels

A general class of lumped parameter models describing the local dynamics of a tri-trophic chain in a controlled environment is analyzed in detail. The trophic functions characterizing the interactions are defined only by some properties and allow us to treat both prey-dependent and ratio-dependent models in a unified manner. Conditions for existence and stability of extinction and coexistence equilibrium states are determined. Some peculiar aspects of the dynamics of the system depending on the bioecological parameters are presented, with particular attention to bistability situations, limit cycles and chaotic behaviours.     

苦瓜的营养价值、化学成分以及药理作用研究进展

本文总结了半个多世纪来国内外学者对苦瓜的研究,为苦瓜进一步开发提供了借鉴。     

Two into One Won’t Go: Conceptual, Clinical, Ethical and Legal Impedimenta to the Convergence of CAM and Orthodox Medicine

The convergence of complementary and alternative medicine (CAM) and evidence-based medicine (EBM) is a prominent feature of healthcare in western countries, but it is currently undertheorised, and its implications have been insufficiently considered. Two models of convergence are described – the totally integrated evidence-based model (TI) and the multicultural-pluralistic model (MP). Both models are being incorporated into general medical practice. Against the background of the reasons for the increasing utilisation of CAM by the public and by general practitioners, TI-convergence is supported and MP-convergence is rejected. MP-convergence is epistemologically and clinically incoherent, and it cannot be regulated. It is also inconsistent with developments in the legal determination of the standard of care for both diagnosis/treatment and disclosure. These claims concerning MP-convergence are justified by the fact that science is not a member of the group of perspectives or world-views which postmodernism treats as equally valid, and this is especially important for healthcare.     

菠萝蜜研究概述(综述)

从植物形态及资源、生物学特性及繁殖、营养及药理、开发利用等方面对菠萝蜜的研究进行综述,旨在推动我国热带、亚热带地区菠萝蜜的发展。     

如何上好“绪论”第一课：以“普通植物病理学”课程为例

“绪论”是高校所有课程的第一课,上好“绪论”第一课可第一时间在学生心中播下对该门学科的使命感、进取心和责任心的“种子”。作者通过多年的教学研究与实践,认为“绪论”教学的首要目的是激发学生的好奇心和求知欲,点燃学生的进取心和紧迫感,进而喜欢和会学这门课程。为达到上述教学目的,我们构建了“绪论”第一课授课内容、方法与目的三者相吻合的教学模式：首先,采用生动有趣和灵活多样的手段导入情景和实物,并设问;随后通过循循善诱和启迪独立思考,师生共同探究和感悟该学科属性、形成发展历史、目前研究现状及未来发展前景,以及教与学的目的、任务和方法等,从而让学生树立上进心和责任心,增强学好该课程的决心和信心。本文以普通植物病理学课程为例,展示了采用“绪论”第一课的教学模式开展的教学过程。多年的教学实践证明,“绪论”第一课教学模式导入的“绪论”内容规范、系统、全面、与教学目标相契合。并且,其内涵丰富、可操作性强、实施效果好,对提高教学质量十分奏效,适合推广应用。     

以提高教学质量为目标开展“普通植物病理学”课程考试改革

为进一步提高教学质量,培养高素质人才,高校应加大课程考试改革的力度。本文针对“普通植物病理学”课程考试中存在的主要问题,结合课程教学的特点,坚持理论联系实际,积极探索了贯穿于课程教学全过程,能够促进学生提高能力和素质的多元化的综合考核模式。     

Inhibition of Nicotinamide Phosphoribosyltransferase (NAMPT), an Enzyme Essential for NAD+ Biosynthesis,Leads to Altered Carbohydrate Metabolism in Cancer Cells

Nicotinamide phosphoribosyltransferase (NAMPT) has been extensively studied due to its essential role in NAD⁺ biosynthesis in cancer cells and the prospect of developing novel therapeutics. To understand how NAMPT regulates cellular metabolism, we have shown that the treatment with FK866, a specific NAMPT inhibitor, leads to attenuation of glycolysis by blocking the glyceraldehyde 3-phosphate dehydrogenase step (Tan, B., Young, D. A., Lu, Z. H., Wang, T., Meier, T. I., Shepard, R. L., Roth, K., Zhai, Y., Huss, K., Kuo, M. S., Gillig, J., Parthasarathy, S., Burkholder, T. P., Smith, M. C., Geeganage, S., and Zhao, G. (2013) Pharmacological inhibition of nicotinamide phosphoribosyltransferase (NAMPT), an enzyme essential for NAD⁺ biosynthesis, in human cancer cells: metabolic basis and potential clinical implications. J. Biol. Chem. 288, 3500–3511). Due to technical limitations, we failed to separate isotopomers of phosphorylated sugars. In this study, we developed an enabling LC-MS methodology. Using this, we confirmed the previous findings and also showed that NAMPT inhibition led to accumulation of fructose 1-phosphate and sedoheptulose 1-phosphate but not glucose 6-phosphate, fructose 6-phosphate, and sedoheptulose 7-phosphate as previously thought. To investigate the metabolic basis of the metabolite formation, we carried out biochemical and cellular studies and established the following. First, glucose-labeling studies indicated that fructose 1-phosphate was derived from dihydroxyacetone phosphate and glyceraldehyde, and sedoheptulose 1-phosphate was derived from dihydroxyacetone phosphate and erythrose via an aldolase reaction. Second, biochemical studies showed that aldolase indeed catalyzed these reactions. Third, glyceraldehyde- and erythrose-labeling studies showed increased incorporation of corresponding labels into fructose 1-phosphate and sedoheptulose 1-phosphate in FK866-treated cells. Fourth, NAMPT inhibition led to increased glyceraldehyde and erythrose levels in the cell. Finally, glucose-labeling studies showed accumulated fructose 1,6-bisphosphate in FK866-treated cells mainly derived from dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. Taken together, this study shows that NAMPT inhibition leads to attenuation of glycolysis, resulting in further perturbation of carbohydrate metabolism in cancer cells. The potential clinical implications of these findings are also discussed.     

FTA卡和普通定性滤纸提取DNA方法研究

用FTA采样卡和普通定性滤纸采集藏绵羊血样,采用NaOH法提取血液基因组DNA,利用设计的一对引物对DRB1基因第三外显子进行扩增,通过PCR产物琼脂糖凝胶检测,对普通定性滤纸与FTA采样卡的两种提取DNA的方法进行比较,结果认为采用普通定性滤纸-NaOH法提取血液基因组DNA,NaOH的最佳洗涤浓度是25 mmol/L,采用FTA-NaOH法提取血液基因组DNA,NaOH的最佳洗涤浓度是20 mmol/L,但普通定性滤纸法提取血液基因组DNA平均成本远低于FTA采样卡,普通定性滤纸法提取血液基因组DNA具有快速、便捷、经济及高效的特点.