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21.
Amylase activity in developing mango fruits increased parallel to the increase in fruit weight. During ripening there was a decrease in starch content and an increase in the reducing and non-reducing sugars. The enzyme preparation which was extracted from acetone powders of mango fruit was inhibited by inhibitors of both α- and β-amylases, and mercapto-ethanol reversed the inhibition by p-hydroxymercuribenzoate. Polyacrylamide gel electrophoresis of the solubilized enzyme has shown only one main band of amylase activity and has indicated the presence of a proteinaceous amylase inhibitor in the fruit pulp. Changes taking place during development and ripening, as well as the nature of the amylolytic activity in mango fruits, are discussed.  相似文献   
22.
Natural populations of the opossum pipefish, Microphis brachyurus, are affected in Mexico by anthropogenic alteration of their habitat and unregulated fishing as this species is traded as an aquarium fish without formal records as occurs with other syngnathids around the world. M. brachyurus is an estuarine fish adapted to salinity fluctuations. The aim of this study was to examine the effect on growth, condition, and survival of juvenile pipefish cultured for 4 wk at salinities of 0, 8, and 16 g/L. Pipefish were fed enriched Artemia nauplii maintaining a ration rate of 14% body weight per day (dry weight Artemia: wet weight fish). Pipefish cultured at 16 g/L showed lower survival (40%) than those at 0 and 8 g/L (100 and 96%, respectively), while juveniles cultured in 8 and 16 g/L were heavier (0.393 and 0.388 g, respectively), longer (9.9 cm), and grew faster (1.4) than those in 0 g/L (0.294 g, 9.1 cm, and 0.44, respectively). This study is the first to report that a salinity of 16 g/L compromises M. brachyurus culture potential and a salinity of 0 g/L caused poor growth while the optimal salinity for the species appears to be around 8 g/L.  相似文献   
23.
In two distinct commercial swine herds, poor weight gain and an increased number of animals showing wasting were observed among nursery and growing pigs. Cases of postweaning multisystemic wasting syndrome (PMWS) and infection with Haemophilus parasuis had been previously diagnosed in these herds. One growing wasted pig from each herd was necropsied and showed enlarged lymph nodes. Pseudomembranous material adhered to the dorsum of the tongue, soft and hard palate in case 1, and in case 2, fibrinous material was seen as whitish plaques on the oesophageal surface with hyperkeratosis of the non-glandular stomach. The main histological lesions in both cases were found in lymphoid tissues with a multifocal accentuated lymphohistiocytic infiltrate, areas of lymphoid depletion and intracytoplasmic inclusions in histiocytic cells in lymph nodes and Payer's patches. Focally, extensive ulceration was found in the stratified pavement epithelium of the tongue with necrosis and necrosuppurative infiltrate in case 1; in case 2, there was ulceration in the stomach with lymphohistiocytic infiltrate in the submucosa and ulceration in the mucosa of the oesophagus associated with yeast cells and pseudo-hyphae. Candida albicans was isolated from the oral cavity lesions. Immunohistochemistry of the lymph nodes was positive for porcine circovirus 2 (PCV2). The association between PMWS and mucocutaneous candidiasis reported here supports the potential immunosuppressive state of PMWS infected pigs.  相似文献   
24.
安静发情母牛无明显发情行为,但具有正常卵泡发育、排卵过程,尚无理想的发情鉴定方法,常常错过人工输精最佳时机,导致产犊间隔延长,饲养成本增加。为此,本文综述了安静发情的鉴定方法概况及母牛安静发情的可能诱因。并指出,科学的管理及合理的营养可尽量减少母牛安静发情。此外,深入挖掘粪便、尿液、乳汁等发情标志物,研究其化合物在发情周期中的变化规律,并借助物联网、生物信息等技术,研发更精准、高效的发情鉴定技术,就有可能彻底突破安静发情鉴定技术瓶颈。  相似文献   
25.
‘Granny Smith’ apples are highly susceptible to superficial scald, a symptom of chilling injury. For many crops, low temperature storage results in oxidative stress and chilling injury, caused by increased production of superoxide anions which in turn leads to the generation of other dangerous reactive oxygen species (ROS). Application, prior to cold storage, of low oxygen (LO2, <0.5%) atmospheres, ethanol (<2% vapour) or 1-methylcyclopropene (1-MCP, 0.5 μL L−1) at 20 °C, was effective in reducing superficial scald in fruit following 24 weeks of cold storage. ROS levels were measured by confocal laser-scanning microscopy of apple peel treated with the fluorescent probe 2′,7′-dichlorodihydrofluorescein diacetate. In control fruit, ROS levels increased during cold storage and shelf-life and were very high after only 8 weeks, whereas in 1-MCP-, ethanol- and LO2-treated fruit, ROS levels remained low throughout storage. Gene-expression levels of ROS-scavenging enzymes were induced by the various pretreatments: catalase (MdCAT) was induced by LO2 treatment, whereas Mn superoxide dismutase (MdMnSOD) was induced by 1-MCP treatment. Polyphenol oxidase (MdPPO) gene expression levels were associated with scald symptom development and were highest in control fruit. Ethylene levels and expression of ethylene biosynthesis genes were correlated with α-farnesene levels and <alpha>-farnesene synthase (MdAFS) gene expression in the variously treated fruit. Accumulation of the α-farnesene oxidation product, 6-methyl-5-hepten-2-one (MHO), was highest in control fruit after 8 weeks, in accordance with ROS accumulation. The LO2 pretreatment mechanism might involve production of anaerobic metabolites, causing a delay in ethylene and α-farnesene biosynthesis and oxidation; this is different from the mechansism of action of 1-MCP, even though both consequently reduce ROS accumulation and scald symptoms.  相似文献   
26.
The solid wastes were obtained from enzymatic extraction of soybean oil using four enzyme systems (Alcalase/Celluclast or Alcalase/Viscozyme L) each with two pH conditions: controlled or not controlled. This last option gave a better oil extraction, regardless of the enzymes used. The ash levels were higher for the enzyme systems subjected to controlled pH, depending on the buffer solutions used. The others constituents presented similar values between each other. The monosaccharides with highest concentrations were galactose, followed by glucose and arabinose. The physical analysis showed that the waste residues had good oil binding capacity. The SEM and epifluorescence microscopy revealed the microstructure of the beans and raw materials, as well as the changes caused by the extraction procedures.  相似文献   
27.
A major challenge in forest management is the ability to quickly and accurately predict bole volume of standing trees. This study presents a new model that uses Multilayer Perceptron (MLP) artificial neural networks for predicting tree diameters values. The model requires three diameter measures at the base of the tree, and recursively predicts other diameter measures. The predicted diameters allow for calculating tree volume using the Smalian method. The performance of the proposed model was satisfactory when compared with data obtained from tree scaling and volume equations.  相似文献   
28.
Understanding the mechanisms that sustain immunological nonreactivity is essential for maintaining tissue in syngeneic and allogeneic settings, such as transplantation and pregnancy tolerance. While most transplantation rejections occur due to the adaptive immune response, the proinflammatory response of innate immunity is necessary for the activation of adaptive immunity. Botryllus schlosseri, a colonial tunicate, which is the nearest invertebrate group to the vertebrates, is devoid of T- and B-cell-based adaptive immunity. It has unique characteristics that make it a valuable model system for studying innate immunity mechanisms: (i) a natural allogeneic transplantation phenomenon that results in either fusion or rejection; (ii) whole animal regeneration and noninflammatory resorption on a weekly basis; (iii) allogeneic resorption which is comparable to human chronic rejection. Recent studies in B. schlosseri have led to the recognition of a molecular and cellular framework underlying the innate immunity loss of tolerance to allogeneic tissues. Additionally, B. schlosseri was developed as a model for studying hematopoietic stem cell (HSC) transplantation, and it provides further insights into the similarities between the HSC niches of human and B. schlosseri. In this review, we discuss why studying the molecular and cellular pathways that direct successful innate immune tolerance in B. schlosseri can provide novel insights into and potential modulations of these immune processes in humans.  相似文献   
29.
Marine sediments host diverse actinomycetes that serve as a source of new natural products to combat infectious diseases and cancer. Here, we report the biodiversity, bioactivities against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and ovarian cancer, and metabolites variation among culturable actinomycetes isolated from the marine sediments of Visayan Sea, Philippines. We identified 15 Streptomyces species based on a 16S rRNA gene sequence analysis. The crude extracts of 10 Streptomyces species have inhibited the growth of ESKAPE pathogens with minimum inhibitory concentration (MIC) values ranging from 0.312 mg/mL to 20 mg/mL depending on the strain and pathogens targeted. Additionally, ten crude extracts have antiproliferative activity against A2780 human ovarian carcinoma at 2 mg/mL. To highlight, we observed that four phylogenetically identical Streptomyces albogriseolus strains demonstrated variation in antibiotic and anticancer activities. These strains harbored type I and II polyketide synthase (PKS) and non-ribosomal synthetase (NRPS) genes in their genomes, implying that their bioactivity is independent of the polymerase chain reaction (PCR)-detected bio-synthetic gene clusters (BGCs) in this study. Metabolite profiling revealed that the taxonomically identical strains produced core and strain-specific metabolites. Thus, the chemical diversity among these strains influences the variation observed in their biological activities. This study expanded our knowledge on the potential of marine-derived Streptomyces residing from the unexplored regions of the Visayan Sea as a source of small molecules against ESKAPE pathogens and cancer. It also highlights that Streptomyces species strains produce unique strain-specific secondary metabolites; thus, offering new chemical space for natural product discovery.  相似文献   
30.
The aim of this work was to evaluate the chemical properties of the residues from erva-mate processing and also to determine the candy-making performance with addition of residues from erva-mate on consumers' acceptance and purchase intent of this new product. The candies containing different amounts of mate powder were evaluated through overall acceptability test and purchase intent. Mate powder showed high contents of dietary fiber, total ash, and total polyphenols. The total dietary fiber content of the mate candies ranged from 5.7 to 6.29% on a dry matter basis. Supplementation with mate powder caused significant increases in polyphenol and mineral contents of mate candies. The incorporation of mate powder increased the hardness of the candies and produced desirable results in their nutritional characteristics. The sensory tests indicated that mate candies were acceptable and approved in relation to purchase intent.  相似文献   
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