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11.
试验旨在探究猪精液6-磷酸果糖激酶(6-phosphofructokinase,PFKL)基因的理化性质和结构特点,以期阐明糖酵解在精子发生过程中的生理作用及调控机制。通过RT-PCR技术扩增PFKL基因,将获得的基因片段插入到pUC57载体上进行克隆测序,并结合生物信息学方法预测和分析其氨基酸序列、跨膜结构、修饰位点、二级结构、三级结构、抗原位点、功能注释等。结果表明,PFKL基因全长2 349 bp,编码782个氨基酸,蛋白质分子质量为83.819 ku,等电点为6.96,为酸性蛋白质,分子式为C3674H5897N1051O1109S40。猪源PFKL基因与鼠、鸭、羊、牛、猩猩、人的参考序列同源性均高达80.0%以上。该蛋白不存在跨膜结构和信号肽区域,含有2个N-糖基化修饰位点、14个O-糖基化位点、35个磷酸化位点。PFKL蛋白三维建模结构主要由无规则卷曲和α-螺旋构成,与肌肉型磷酸果糖激酶和血小板型磷酸果糖激酶的同源性分别为68.24%和70.84%。PFKL基因含有的27个抗原位点强弱不同,柔韧性分布较均匀,有较高的表面可塑性,且存在PKC、PKA特异性蛋白激酶的结合位点,为具有较多潜在B细胞抗原表位的亲水性蛋白。GO功能注释分析结果表明,PFKL基因具有碳水化合物激酶活性、磷酸果糖激酶活性,能够参与己糖代谢和单糖代谢。本研究结果为改善精子品质和提高精卵结合发生率奠定了分子生物学基础。  相似文献   
12.
The effect of dipyridamole--an adenosine uptake inhibitor--on the plasma concentration of free fatty acids (FFA), glucose, lactate and cyclic adenosine monophosphate (cAMP) has been examined in 2 groups of Landrace pigs representing low (Ada 0) and high (Ada A) red cell adenosine deaminase (Ada) activity. Pigs fitted with a jugular vein catheter were given dipyridamole (0.16 mg/kg/min) over a period of 30 min. The infusions were performed 22 h after the last meal at a time where pigs were found to show steady increase and decline in rates of lipolysis and glycogenolysis, respectively. The results showed that lipid mobilization as identified by the plasma FFA concentration was markedly depressed. During the infusion of dipyridamole similar degree of inhibition was seen in Ada 0 and Ada A pigs, however, in the period following the infusion, a significantly stronger suppression persisted in the Ada 0 pigs. Both the blood glucose and lactate level rose distinctly as a result of the dipyridamole treatment. This stimulation of the glycolysis rate was significantly more expressed in Ada 0 pigs compared to that of the Ada A pigs. When theophylline, an antagonist of adenosine, was given together with dipyridamole, the rise in the lactate level was considerably diminished. Dipyridamole also produced a distinct rise in the plasma cAMP levels.  相似文献   
13.
【目的】测定PFKM基因在伊犁马不同组织部位中的差异表达,为该基因在伊犁马的糖酵解过程中功能提供一定基础。【方法】以伊犁马为试验动物,分别提取心脏、肝脏、夹肌、斜方肌、背阔肌、臀中肌、半腱肌以及腹外斜肌8种组织的总RNA,以伊犁马不同组织的RNA为模板,逆转录合成cDNA,GAPDH为内参基因,运用荧光定量PCR的方法检测PFKM基因mRNA在伊犁马不同组织间的相对表达量。运用酶联免疫法(Elisa)检测伊犁马不同组织中糖酵解相关酶的含量。【结果】伊犁马PFKM基因在以上8种组织部位中都有表达,在心脏中相对表达量最高,肝脏中相对表达量最低,心脏中PFKM基因mRNA相对表达量极显著高于马匹其他部位(P<0.01)。马匹心脏组织中6-磷酸果糖激酶的活性显著高于其他部位。【结论】在糖酵解途径中,PFKM基因6-磷酸果糖激酶对心脏组织的糖酵解有重要的影响。  相似文献   
14.
15.
Objective: To review the physiology of lactate production and metabolism, the causes of lactic acidosis, and the current applications of lactate monitoring in humans and animals. Data sources: Human and veterinary studies. Summary: Lactate production is the result of anaerobic metabolism. Tissue hypoxia due to hypoperfusion is the most common cause of lactic acidosis. Studies in critically ill humans have shown that serial lactate monitoring can be used to assess the severity of illness and response to therapy. Several veterinary studies have also shown lactate as a useful tool to assess severity of illness. Conclusions: Lactate measurement in critically ill veterinary patients is practical and can provide information to assess severity of illness. Further veterinary studies are needed to establish the value of serial lactate measurements for prognostic and therapeutic purposes. Information regarding lactate measurement in cats is limited, and further studies are warranted.  相似文献   
16.
17.
The goal of this prospective pilot study was to use naturally occurring canine mast cell tumors of various grades and stages as a model for attempting to determine how glucose uptake and markers of biologic behavior are correlated. It was hypothesized that enhanced glucose uptake, as measured by 2‐[fluorine‐18]fluoro‐d ‐glucose‐positron emission tomography/computed tomography (F18 FDG PET‐CT), would correlate with histologic grade. Dogs were recruited for this study from a population referred for treatment of cytologically or histologically confirmed mast cell tumors. Patients were staged utilizing standard of care methods (abdominal ultrasound and three view thoracic radiographs), followed by a whole body F18 FDG PET‐CT. Results of the F18 FDG PET‐CT were analyzed for possible metastasis and standard uptake value maximum (SUVmax) of identified lesions. Incisional or excisional biopsies of the accessible mast cell tumors were obtained and histology performed. Results were then analyzed to look for a possible correlation between the grade of mast cell tumors and SUVmax. A total of nine animals were included in the sample. Findings indicated that there was a correlation between grade of mast cell tumors and SUVmax as determined by F18 FDG PET‐CT (p‐value = 0.073, significance ≤ 0.1). Based on the limited power of this study, it is felt that further research to examine the relationship between glucose utilization and biologic aggressiveness in canine mast cell tumors is warranted. This study was unable to show that F18 FDG PET‐CT was a better staging tool than standard of care methods.  相似文献   
18.
Photodynamic therapy (PDT) holds great promise in treating veterinary and human dermatological neoplasms, including equine sarcoids, but is currently hindered by the amount of photosensitiser and light that can be delivered to lesions thicker than around 2 mm, and by the intrinsic antioxidant defences of tumour cells. We have developed a new PDT technique that combines an efficient transdermal penetration enhancer solution, for topical delivery of 5‐aminolevulinic acid (ALA) photosensitiser, with acute topical post‐PDT application of the glycolysis inhibitor lonidamine. We show that the new PDT combination treatment selectively kills sarcoid cells in vitro, with repeated rounds of treatment increasing sarcoid sensitisation to PDT. In vivo, ALA PDT followed by 600 μM lonidamine substantially improves treatment outcomes for occult, verrucous, nodular and fibroblastic sarcoids after 1 month (93% treatment response in 27 sarcoids), compared with PDT using only ALA (14% treatment response in 7 sarcoids).  相似文献   
19.
Five experimental diets with different carbohydrates/lipid ratio (CHO:L, 0.75, 1.28, 2.10, 2.52, 4.63) were formulated. Fish were randomly assigned by triplicate (10 fish per tank, 0.50 ± 0.01 g). Growth was registered every 15 days until end of the experiment (45 days). Samples were taken for analysis of chemical carcass composition, blood chemistry, glycogen and lipid liver content, digestive and metabolic enzyme activities. Results showed that survival, growth performance parameters and plasma glucose were not affected by treatments (p > 0.05). Lipids of carcass and liver, as well as triglycerides and plasma cholesterol increase significantly as CHO:L ratio decreased. While an inversely proportional tendency was observed for carcass protein and liver glycogen (p < 0.05). Digestive enzymes did not show significant differences among treatments (p > 0.05). Finally, Hexokinase (HK), glucokinase (GK), phosphoenol pyruvate carboxykinase (PEPCK) and fructose‐1,6‐biphosphase (FBPase) showed high regulation by carbohydrates up to the CHO:L ratio of 2.10 (p < 0.05), while pyruvate kinase (PK) activity was not significantly affected by the CHO:L ratio. By the other side, glucose‐6‐phosphate dehydrogenase (G6PD) tends to significantly increase as the CHO:L ratio increases. We conclude that A. tropicus fry have a high capacity to utilize carbohydrates substituting lipids as energy source in balanced diets.  相似文献   
20.
The influence of ontogeny and nutrition on metabolic enzyme activities in larvae of the African catfish, Clarias gariepinus, was studied. After start of exogenous feeding, the larvae were reared for 10 days under three different nutritional conditions: Artemia nauplii, a dry starter diet, and starvation. The live feed gave the best growth (96 mg within 10 days) whereas the dry diet resulted in low growth (33 mg). This growth difference was reflected in larval RNA and DNA concentrations, but not in the levels of soluble protein. Enzymes representing the following aspects of metabolism have been analysed: NADPH generation (G6PDH, ME), glycolysis (PFK, PK), gluconeogenesis (FDPase), amino acid catabolism (GOT, GPT) and oxidative catabolism (CS). All enzymes were present from the start of exogenous feeding onwards, but their maximum specific activities displayed different developmental patterns. In catfish larvae fed on Artemia, G6PDH and ME activities steadily increased with age and weight of the larvae. CS levels remained, after an immediate enhancement upon onset of exogenous feeding, on a rather stable plateau. The amino acid-degrading enzymes GOT and GPT showed maximum levels at days 3–5 of feeding or at a body weight of 10–20 mg, but decreased thereafter. Activities of PFK, PK and FDPase showed low initial levels, and increased significantly with age and size. Based on the ontogenetic patterns of metabolic enzymes, in C. gariepinus larvae an early and a late developmental phase can be distinguished. During the early phase, the glycolytic and gluconeogenetic capacities are low, whereas they are enforced during the later phase. The oxidative capacity is high both during the early and the late phase. The metabolic changes in catfish development coincide with other major ontogenetic events, e.g., alterations of muscle organization, gill morphology, respiration and stomach structure and function. Rearing catfish larvae on a dry diet instead of Artemia partly altered the developmental pattern described: The ontogenetic elevation of CS, PFK and FDPase was delayed and the early peak in GOT and GPT activities was not realized. Particularly during the early developmental phase, the enzyme behaviour of the larvae fed on dry food was similar to that of starved larvae.Abbreviations CS citrate synthase - FDPase fructose-1,6-diphosphatase - GOT glutamate oxaloacetate transaminase - GPT glutamate pyruvate transaminase - G6PDH glucose-6-phosphate dehydrogenase - ME malic enzyme - PFK phosphofructokinase - PK pyruvate kinase  相似文献   
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