Role of green fluorescent proteins and their variants in development of FRET-based sensors

Since the last decade, a lot of advancement has been made to understand biological processes involving complex intracellular pathways. The major challenge faced was monitoring and trafficking of metabolites in real time. Although a range of quantitative and imaging techniques have been developed so far, the discovery of green fluorescent proteins (GFPs) has revolutionized the advancement in the field of metabolomics. GFPs and their variants have enabled researchers to ‘paint’ a wide range of biological molecules. Fluorescence resonance energy transfer (FRET)-based genetically encoded sensors is a promising technology to decipher the real-time monitoring of the cellular events inside living cells. GFPs and their variants, due to their intrinsic fluorescence properties, are extensively being used nowadays in cell-based assays. This review focuses on structure and function of GFP and its derivatives, mechanism emission and their use in the development of FRET-based sensors for metabolites.     

Long-term changes of a waterbird community over 26 years at a Pakistani Ramsar Site

Wetlands Ecology and Management - Long-term data of local bird communities have shown changes over the past few decades due to anthropogenic pressures, especially in temperate regions. However, we...     

夏玉米水分利用效率的时空变化规律研究

通过小区试验,本实验在不同生育阶段控水条件下,对玉米不分利用效率（ＷＵＥ）的时空变化规律进行研究。同雄期是玉米的需水关键期,该时期控制供水较充分,供水减产１８．２％,ＷＵＥ减小１６．８％灌浆期适度控水有利于节水增产。拔节期供水对作物株高和干物质积累影响明显,拔节期耗水量对玉米产量形成重要。     

In vitro examination of anti-parasitic,anti-Alzheimer,insecticidal and cytotoxic potential of Ajuga bracteosa Wallich leaves extracts

This research study is mainly focused to evaluate the anti-parasitic, insecticidal, cytotoxic and anti-alzheimer potential of various leaf extracts of Ajuga bracteosa Wallich ex Bentham. 04 different extracts were prepared using solvent of different polarity to determine the best candidate for potent bioactivity i.e. n-hexane (NH), Ethyl acetate (EA), Ethanol (EL) and Chloroform (CH). Concentrations of each extracts were made specified for all activities. All extracts were exploited for broad range of biomedical applications including leishmaniasis, in vitro anti-Alzheimer, insecticidal and cytotoxic studies. Our results showed that A. bracteosa n-hexane extract was highly active against Leishmania Tropica with significant inhibition of 58 ± 1.61 for promastigote and 63 ± 2.29 for amastigote at 1000 μg/mL. Furthermore, promising anti-alzheimer activity acetylcholinesterase (AChE) 46 ± 0.83 and butrylcholineterase (BChE) 49 ± 1.17 was noted for n-hexane. The insecticidal potential of these extracts were test against five different insects (Rhyzopertha dominica, Trogoderma granarium, Tribolium castaneum, Sitophilus oryze, and Callosobruchus analis). The higest mortality rate of insecticidal activity was recorded by n-hexane followed by Ethyl acetate whereas ethanol extract was found to be less effective against all the test species. Significant cytotoxic potential of each plant sample against Artemia salina thus aware us for further detailed research to find out novel drugs. Based on our results we believe that Ajuga bracteosa could be used to develop as a potential botanical insecticide against different insect and pests, such as aphids as well as an excellent source for the compound isolation as anti-tumor agent.     

Physiological responses of the green microalga Acutodesmus dimorphus to temperature induced oxidative stress conditions

Temperature is the most critical factor that directly affects the physiological functioning and metabolic activities of any organism. With rising global temperature, understanding the heat stress response of an organism is critically important. In the present study, we investigated differences in the early changes occurring upon heat stress in the green microalga Acutodesmus dimorphus, a potential strain for biofuel production. The cells were heat-stressed at 45 and 50°C for 24 h and the temporal response of cells in terms of growth, pigments content, levels of oxidative stress biomarkers i.e., reactive oxygen species (ROS) and the response of enzymatic and non-enzymatic antioxidant scavengers were evaluated. The results revealed that after 24 h of heat stress at 45°C, the accumulations of chlorophyll a and carotenoids remained stable; all three ROS increased with the higher activities of various enzymatic and non-enzymatic antioxidants. On the contrary, at a higher temperature of 50°C, the accumulations of chlorophyll a, carotenoids and non-enzymatic antioxidants reduced drastically while the accumulations of all three ROS and the response of enzymatic antioxidants were significantly higher than those at 45°C. These results suggest that the cells utilize several stress acclimatization mechanisms to cope up the heat stress. There was a dramatic difference in the physiological changes and cellular antioxidant mechanism upon heat stress at 45 and 50°C. The cellular defense response of A. dimorphus gets impaired after heat stress at 50°C but remains active at 45°C, exhibiting the heat resistance and, thus, the thermotolerance.     

胰腺癌中小肠细菌过度生长及炎症介质异常表达分析

目的本研究通过检测胰腺癌患者小肠细菌过度生长(SIBO)、癌组织中IL 1β、IL 6和TNF α的表达水平,探讨胰腺癌患者是否更易发生SIBO及SIBO伴随的炎症介质水平变化。方法采用葡萄糖氢呼气试验(HBT)检测40例胰腺癌患者和40例健康查体人群的SIBO的发生情况。采用免疫组织化学技术(IHC)测定胰腺癌组织中IL 1β、IL 6和TNF α的表达情况,分析与胰腺癌临床病理的关系。结果胰腺癌组SIBO阳性率为60.0%,健康对照组SIBO阳性率为15.0%,胰腺癌组SIBO阳性率显著高于对照组(P<0.001)。在胰腺癌患者SIBO阳性组和阴性组间IL 1β、IL 6、TNF α表达水平有显著差异(P<0.05)。胰腺癌患者癌组织中IL 1β的表达与分化程度及临床分期差异具有统计学意义(P<0.05)。IL 6的表达在淋巴结是否转移及年龄的差异具有统计学意义(P<0.05)。TNF α的表达在分化程度及淋巴结是否转移的分布差异具有统计学意义(P<0.05)。结论胰腺癌患者较健康人更容易发生SIBO,SIBO可能通过促进IL 1β、IL 6及TNF α的表达影响胰腺癌的发生发展。     

Systemic Non-Reproductive Effects of Sex Steroids in Adult Males and Females

Sex steroids are well known for their reproductive actions, however, their roles are not confined to reproduction only and they have been shown to exert wide ranging effects on systemic physiology. Further, the effects of the so-called male and female sex steroids are not limited to their respective genders but they are present in both sexes where they have a significant impact upon systemic functions, reproductive as well as non-reproductive. This work reviews the existing knowledge base and recent reports on the effects of sex steroids on non-reproductive physiology.     

The nature of the carbohydrate binding module determines the catalytic efficiency of xylanase Z of Clostridium thermocellum

Xylanase Z of Clostridium thermocellum exists as a complex in the cellulosome with N-terminus feruloyl esterase, a carbohydrate binding module (CBM6) and a dockerin domain. To study the role of the binding modules on the activity of XynZ, different variants with the CBM6 attached to the catalytic domain at its C-terminal (XynZ-CB) and N-terminal (XynZ-BC), and the CBM22 attached at N-terminus (XynZ-B′C) were expressed in Escherichia coli at levels around 30% of the total cell proteins. The activities of XynZ-BC, XynZ-CB and XynZ-B′C were 4200, 4180 and 20,700 U μM⁻¹ against birchwood xylan, respectively. Substrate binding studies showed that in case of XynZ-BC and XynZ-CB the substrate birchwood xylan remaining unbound were 51 and 52%, respectively, whereas in the case of XynZ-B′C the substrate remaining unbound was 39% under the assay conditions used. The molecular docking studies showed that the binding site of CBM22 in XynZ-B′C is more exposed and thus available for substrate binding as compared to the tunnel shape binding pocket produced in XynZ-BC and thus hindering the substrate binding. The substrate binding data for the two constructs are in agreement with this explanation.     

Comparative lipid and uric acid suppressing properties of four common herbs in high fat-induced obese mice with their total phenolic and flavonoid index

Our present study was designed to investigate the comparative anti-obesity efficacy of ethanolic extract of Azadirachta indica A. Juss., Trigonella foenum-graecum L., Allium sativum L. and Zingiber officinale Roscoe in high fat-induced mice with their total phenolic and flavonoid profile. Total phenolic and flavonoid content were determined by Folin–Ciocalteu's and Aluminium chloride UV method respectively. In our study, 55 healthy mice were separated into 11 groups to take their respective treatments. Lipid and uric acid profile were estimated by using the enzymatic colourimetric method. Ethanolic extract of A. indica contained the highest phenolic and flavonoid content. A. indica normal and high fat diet group showed reduced weight gaining tendency than other extract groups. A. indica at a dose of 400 mg/kg body weight significantly (p < 0.001) reduced serum cholesterol (SC), triglyceride (TG), and uric acid (UA) level than other three extracts when compared with the control group. Thus, a considerable correlation was found between serum uric acid reducing potentials of the present experimental extracts with a lipid-lowering profile. Pathological examination revealed that the average weight of liver and kidney were significantly decreased in A. indica normal. Results obtained from the present study it can be concluded that ethanolic extract of A. indica possesses better lipid-lowering efficacy than the other three herbs.     

PACS服务器硬盘阵列故障处理及其预防对策

介绍了我院PACS服务器的磁盘故障及其处理方法,并提出对医院PACS服务器配置和管理上的一些建议。