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31.
AIM: To investigate the antihypertrophic function of adenosine monophosphate-activated protein kinase(AMPK) and its effects on myocardial fatty acid oxidation.METHODS: The model of cardiac hypertrophy was produced by banding abdominal aorta (transaortic constriction, TAC) in male Sprague-Dawley rats. 5-aminoimidazole-4-carboxamide ribonucleoside(AICAR), a pharmacological activator of AMPK, was injected subcutaneously (0.5 mg·kg-1·d-1) 24 hours after operation and continued till 7 weeks after operation. Echocardiographic and ventricular remodeling parameters, free fatty acid concentration in blood serum and myocardium, and expression of peroxisome proliferator-activated receptor(PPARα) and carnitine palmityl transferase(CPT-I) mRNA were investigated after treatment of AICAR or vehicle for 7 weeks. RESULTS: Compared with control group, treatment of rats subjected to TAC with AICAR significantly increased the mRNA expression of PPARα and CPT-I and subsequently decreased free fatty acid concentration in blood and myocardium, improved echocardiographic characteristics, and reduced the increases in the heart weight/body weight ratio and myocyte diameter.CONCLUSION: Pharmacological activation of AMPK may attenuate cardiac hypertrophy through increasing myocardial fatty acid oxidation.  相似文献   
32.
AIM: To investigate the role of high glucose in primary hepatocytes of mice fed with a high fat diet.METHODS: Male C57BL/6J mice were fed a high fat (45% of calories) diet ad libitum for 6 weeks to induce hepatic steatosis. Primary hepatocytes were isolated from the mouse liver by the 2 step collagenase perfusion method. The cells were incubated in low glucose (5 mmol/L), low glucose plus mannitol (30 mmol/L), or high glucose (35 mmol/L) DMEM medium for 12 h. The cell viability, apoptosis, mitochondrial membrane potential, and caspase enzymatic activities were measured. Furthermore, proteins related to the stress-sensitive signaling pathway of regulating high glucose-induced apoptosis in primary hepatocytes were determined by Western blotting.RESULTS: Incubation with 35 mmol/L glucose resulted in a significant decrease in cell viability and an increase in apoptosis, whereas mannitol had no significant effect on the cell viability or apoptosis. A progressive depolarization of the mitochondria, an increase in cytosol cytochrome C and a dramatic decrease in mitochondrial cytochrome C in high-glucose stressed hepatocytes were observed. The enzymatic activities of caspase-9 and caspase-3, but not caspase-8, were significantly increased in high glucose-stressed hepatocytes (P<0.05). High glucose treatment suppressed the expression of Bcl-2 and Bcl-xL, while it increased the expression of the pro-apoptotic factor Bax.CONCLUSION: High glucose stress reduces mitochondrial membrane potential, initiates mitochondria-mediated apoptotic pathways and promotes apoptosis of hepatocytes with steatosis. This may be an important pathological mechanism of hyperglycemia-induced progression of nonalcoholic fatty liver disease.  相似文献   
33.
AIM:To investigate the effect of mitochondrial aconitase (ACO2) on energy synthesis during aging in male SD rats and D-galactose-induced cell aging model. METHODS:D-galactose at concentration of 55 mmol/L was used to establish MRC-5 cell aging model. Intact mitochondria in the rat brain and MRC-5 cells were isolated by a sucrose density gradient centrifugation. The formation of NADPH was used to represent the ACO2 activity and determined by observation of the absorbance at 340 nm. Fluorescence quantitative PCR and Western blotting were applied to detected ACO2 expression. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured by the commercial assay kits. The tissue iron content was detected by ferrozine method. Mitochondrial membrane potential was detected by JC-1 mitochondrial membrane potential detection kit. The content of ATP, ADP and AMP was measured by HPLC analysis, and the energy charge was then calculated by the formula. RESULTS:ACO2 activity and iron content presented age-related decline and increase, respectively, while the expression level of ACO2 kept stable. ACO2 activity significantly declined when the cells were treated with hydrogen peroxide at different concentrations. In the aging cells, SOD activity and ACO2 activity were decreased and MDA content was increased significantly, while the expression level of ACO2 was unchanged. During aging, mitochondrial membrane potential, ATP synthesis and energy charge presented significant reduction. CONCLUSION:The activity of ACO2, which is sensitive to oxidative stress, declines during aging, and may affect the efficiency of the Krebs cycle. At the same time, mitochondrial membrane potential decreases, thus reducing the energy synthesis in mitochondria.  相似文献   
34.
AIM:To explore the characteristics of energy metabolism in brain mitochondria of rats exposed to acute and chronic hypoxia. METHODS: Animal grouping: Wistar rats were randomized into acute hypoxic group (AH), chronic hypoxic group (CH) and the control. Respiratory function, F0F1-ATPase activity, mitochondrial ATP, ADP and AMP contents and ATP production rate were measured respectively. RESULTS: In AH, brain mitochondrial respiratory state IV (ST4) was increased, while respiratory control rate (RCR), mitochondrial ATP content, ATP production rate and F0F1-ATPase activity were decreased respectively. In CH, ST4, RCR, mitochondrial ATP content and F0F1-ATPase activity were reversed partially.CONCLUSION: Acute hypoxia may impair brain mitochondria energy metabolism by way of depressing mitochondrial oxidative phosphorylation and ATP production and these parameters gain partial reablement during chronic hypoxia.  相似文献   
35.
Nitric oxide (NO) is an intra- and intercellular messenger with a broad spectrumof activities in the central nervous system, cardiovascular and immune systems. Mitochondrial nitric oxide synthase (mt-NOS), which might be a new form of NOS in mitochondria, has been discovered to be active in the regulation ofmitochondrial respiration, energy metabolism and many pathophysiological processes.In this review, the location, properties, physiological and pathophysiological significance of mtNOS were summarized.  相似文献   
36.
The study was conducted to investigate the effect of early feed restriction (ER) on lipid metabolism and mitochondrial function in the liver of broiler chickens. Newly hatched broiler chickens were randomly allocated into control and ER group which was subjected to feed restriction with feed provided on alternate days from hatch to 14 days of age (14 d), followed by ad libitum feeding until the end of the experiment on 63 d. ER group exhibited significantly lower body weight throughout the experiment. Serum concentrations of total cholesterol (TC) and high density lipoprotein cholesterol (HDLC) were significantly higher in ER group at 14 d (< 0.05), and the higher serum TC level in ER group was also observed at 63 d. In contrast, the contents of triglyceride (TG), TC and lipoprotein lipase (LPL) activity in liver were significantly lower in ER group at 14 d (< 0.05). At 14 d no significant difference was detected for the mRNA expression of the acetyl-CoA carboxylase-α (ACC-α), carnitine palmitoyltransferase I (CPT-I), sterol regulatory element binding protein-1c (SREBP-1c) or peroxisome proliferator-activated receptors α (PPAR-α) between control and ER group. At 63 d ACC-α mRNA expression was significantly down-regulated accompanied with a significantly up-regulated CPT-ImRNA and a decreased tendency of SREBP-1c mRNA expression in ER group (P = 0.09). Swollen mitochondria with fragmented and reduced cristae were observed in liver of ER group at 14 d. Meanwhile the inner mitochondria membrane viscidity increased and hepatic mitochondrial superoxide dismutase (SOD) activity decreased at 14 d. The results suggest that feed restriction at early postnatal stage may produce long-term effect on lipid metabolism of broiler chicken, probably through, at least in part, alterations in mitochondria morphology and function.  相似文献   
37.
为探讨贮藏年限对不同居群白羊草(Bothriochloa ischaemum)种胚线粒体抗氧化功能的影响,试验以贮藏1~4年的代县、平鲁、平定、柳林及太谷居群白羊草种子为材料,分析其种胚线粒体丙二醛(Malondialdehyde, MDA)含量及超氧化物歧化酶(Superoxide dismutase, SOD)、过氧化氢酶(Catalase, CAT)、抗坏血酸过氧化物酶(Ascorbate peroxidase, APX)和谷胱甘肽还原酶(Glutathione reductase, GR)活性的变化规律。结果表明:各居群白羊草种胚线粒体的抗氧化能力与其贮藏年限关系密切。随着贮藏年限的延长,白羊草种胚线粒体SOD,CAT,APX及GR活性逐渐降低,而其MDA含量逐渐升高。不同居群白羊草种子的耐贮藏性存在差异,太谷居群白羊草种子的贮藏年限可为3年,而代县、平鲁、平定及柳林居群白羊草种子的贮藏年限最好为1年。  相似文献   
38.
The aim of the present study was to address the effect of resveratrol-mediated upregulation of sirtuin 1 (SIRT1) during oocyte maturation on mitochondrial function, the developmental ability of oocytes and on mechanisms responsible for blockage of polyspermic fertilization. Oocytes collected from slaughterhouse-derived ovaries were cultured in TCM-199 medium supplemented with 10% FCS and 0 or 20 µM resveratrol (Res). We examined the effect of Res on SIRT1 expression in in vitro-matured oocytes (Exp 1); fertilization and developmental ability (Exp 2); mitochondrial DNA copy number (Mt number), ATP content and mitochondrial membrane potential in matured oocytes (Exp 3); and the time required for proteinase to dissolve the zona pellucida following in vitro fertilization (as a marker of zona pellucida hardening), as well as on the distribution of cortical granules before and after fertilization (Exp 4). In Exp 1, the 20 µM Res treatment upregulated protein expression of SIRT1 in oocytes. In Exp 2, Res treatment improved the ratio of normal fertilization and the total cell number of blastocysts. In Exp 3, Res treatment significantly increased the ATP content in matured oocytes. Additionally, Res increased the overall Mt number and mitochondrial membrane potential, but the effect was donor-dependent. In Exp 4, Res-induced zona hardening improved the distribution and exocytosis of cortical granules after in vitro fertilization. In conclusion, Res improved the quality of oocytes by improving mitochondrial quantity and quality. In addition, Res added to the maturation medium enhanced SIRT1 protein expression in oocytes and improved fertilization via reinforcement of the mechanisms responsible for blockage of polyspermic fertilization.  相似文献   
39.
XU Bin  LI Yang 《园艺学报》2015,31(12):2291-2295
Mitochondrial calcium homeostasis plays a key role in maintaining various cellular characteristics and mediating cellular physiological function and pathological processes. Although it has long been known that mitochondria takes up Ca2+, the molecular identities of the channels and transporters involved in this process are revealed only recently. Here, we review the structure and function of the channel-forming subunit, mitochondrial calcium uniporter (MCU) and its regulators, which include MICU1, MICU2, and MCUR1.  相似文献   
40.
The whitefly Bemisia tabaci (Gennadius) has caused notable damage to vegetable and cotton crops in the eastern Mediterranean region since about 1994, and has become particularly problematic in southern Turkey beginning in 2000. The development of squash silverleaf symptoms in Cucurbita species and the unprecedented high population levels in the region suggested that the B biotype, notable for the latter phenotypes, had been introduced. To test this hypothesis and determine the host distribution of the suspect introduced B biotype and its associated natural enemies, B. tabaci immature instars and adults, and the associated natural enemies were collected from cultivated and uncultivated plant species. From the southern Turkey collections, B. tabaci was found to colonize 152 species from 43 plant families. Of the plant species upon which B. tabaci was found to reproduce, 152 of them were reported as hosts of B. tabaci in Turkey. Five species of predators and two species of parasitoids were identified as natural enemies of the B biotype of B. tabaci in southern Turkey. Using the mitochondrial cytochrome oxidase I gene all B. tabaci were identified as the B biotype of the B. tabaci complex, at 96–100% shared identity with reference B biotype sequences. Results indicate that this invasive biotype has displaced the local Turkey-cotton haplotype that was known to occur previously in southern Turkey.  相似文献   
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