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121.
L. M. Rey Susanne K. Whitaker Gretchen Stephens 《Journal Of Agricultural & Food Information》2013,14(3):253-270
This article discusses the Veterinary Medical Libraries Section (VMLS) of the Medical Library Association (MLA), its impacts on both librarianship and veterinary medicine during its 40-year history, how it achieved those impacts, relationships, selected projects, and organizational changes through the years. A listing of publications about veterinary librarianship and VMLS products is available on the VMLS website (Veterinary Medical Libraries Section, 2014). 相似文献
122.
123.
Our research on several proteins indicates that accurate molecular weights cannot be determined by Superose 12 column chromatography. In support of this statement, we present data on molecular weights of purified red kidney bean alpha-amylase inhibitor (RKB alphaAI) and white kidney bean alpha-amylase inhibitor (WKB alphaAI) to document this problem. The molecular weight of purified RKB alphaAI determined by Sephadex G-100 gel filtration, polyacrylamide gel electrophoresis, Superose 12 gel filtration and cDNA were 49.0, 51.0, 22.9, and 49.805 kDa (not glycosylated), respectively. The molecular weights of WKB alphaAI by several methods were as follows: Sephadex G-100 gel filtration, 51.0 kDa; Superose 12 gel filtration in 0.2 M NaCl buffer, 23.1 kDa; polyacrylamide gel electrophoresis (PAGE), 51.0 kDa; sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), 45.0 kDa; multiangle laser light scattering (MALLS), 49.940 kDa; laser-assisted time-of-flight mass spectrometry (LATOFMS), 56.714 kDa; and cDNA sequence (with 12.2% carbohydrate), 55.9 kDa. The data indicate there is ionic interaction between proteins and the matrix of Superose 12 in low ionic strength buffers and hydrophobic interaction at higher ionic strength buffers. Researchers should be cautious when using Superose 12 columns for molecular weight determinations. 相似文献
124.
Cystine lyase is the enzyme responsible for off-aroma deterioration in fresh unblanched broccoli. In this research, cystine lyase purification from broccoli has been optimized. Only one protein peak with cystine lyase activity was found during purification. Broccoli cystine lyase was purified 100-fold to homogeneity. L-Cystine, L-cysteine-S-sulfate, L-djenkolic acid, and some S-alkyl-L-cysteines and their sulfoxides are substrates, but the enzyme had negligible activity with L-cystathionine. A K(m) value of 81.2 microM was found for L-cystine. Inhibition and K(i) determinations indicated that L-cysteine is a linear noncompetitive inhibitor with a K(i) of 5 mM and DL-homocysteine is a competitive inhibitor with a K(i) of 1.5 mM. The molecular weight of cystine lyase was determined to be 100 kDa by three methods, with two subunits of 48 kDa each and a carbohydrate content of 3%. Further characterization included cofactor quantification, the effects of temperature and pH on activity and stability, and amino acid composition. 相似文献
125.
Kaware M Bronshtein A Safi J Van Emon JM Chuang JC Hock B Kramer K Altstein M 《Journal of agricultural and food chemistry》2006,54(18):6482-6492
Enzyme-linked immunosorbent assay (ELISA) and sol-gel-based immunoaffinity purification (IAP) methods for the pyrethroid bioallethrin were developed and applied for monitoring bioallethrin in spiked food, soil, and dust samples. Attempts to determine bioallethrin content in fruit and vegetable extracts revealed high variability between sample preparations and marked interferences with the assay. Sol-gel IAP followed by solid-phase sample concentration was effective in removing the interfering components and resulted in high recovery of bioallethrin from spiked crude acetonic extracts of fruits and vegetables, even in the presence of high extract concentrations (28%). Solid-phase treatment alone failed to remove the interfering components from the spiked sample. Gas chromatography-mass spectrometry analysis of the IAP samples revealed bioallethrin as a doublet unsolved peak because of the cis and trans isomer present in the standard with confirmation of its mass. Unlike fruit and vegetable extracts, soil and dust samples did not interfere with the ELISA, and the bioallethrin content in those samples could be determined with high precision without the need of any further purification. 相似文献
126.
Smoke-derived taint in wine: effect of postharvest smoke exposure of grapes on the chemical composition and sensory characteristics of wine 总被引:1,自引:0,他引:1
Kennison KR Wilkinson KL Williams HG Smith JH Gibberd MR 《Journal of agricultural and food chemistry》2007,55(26):10897-10901
Although smoke exposure has been associated with the development of smoke taint in grapes and subsequently in wine, to date there have been no studies that have demonstrated a direct link. In this study, postharvest smoke exposure of grapes was utilized to demonstrate that smoke significantly influences the chemical composition and sensory characteristics of wine and causes an apparent 'smoke taint'. Verdelho grapes were exposed to straw-derived smoke for 1 h and then fermented according to two different winemaking treatments. Control wines were made by fermenting unsmoked grapes. Sensory studies established a perceivable difference between smoked and unsmoked wines; smoked wines were described as exhibiting 'smoky', 'dirty', 'earthy', 'burnt' and 'smoked meat' characteristics. Quantitative analysis, by means of gas chromatography-mass spectrometry, identified guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, eugenol, and furfural in each of the wines made from smoked grapes. However, these compounds were not detected in the unsmoked wines, and their origin is therefore attributed to the application of smoke. Increased ethanol concentrations and browning were also observed in wines made from grapes exposed to smoke. 相似文献
127.
Whitaker DA Goodger WJ Garcia M Perera BM Wittwer F 《Preventive veterinary medicine》1999,38(2-3):119-131
Metabolic profile testing has generally been used as part of a multidisciplinary approach for dairy herds in temperate climates. Our goal was to evaluate the effectiveness of the technique for identifying constraints on productivity in small herds in environments less favorable for milk production. Metabolites tested were chosen for stability in the sample after collection of blood, ease of analysis and practical knowledge of the meaning of the results. Blood levels of five different metabolites in low-producing dairy cows belonging to smallholders in tropical and subtropical environments were measured. The study involved 13 projects with 80 cows in each, carried out in six Latin American, six Asian, and one southern European countries. Data were also collected on feeding, body condition score (BCS) and weight change, parasitism, and reproduction. In Chile, Mexico, Paraguay, Philippines, Uruguay, and Venezuela, globulin levels were high in > 17% of cows sampled on each occasion. Globulin levels were also high in Turkey and Vietnam on one or more occasions. In Paraguay, 49% of cows had high globulin levels at two to three months after calving. These results suggest that inflammatory disease was present to a potentially important degree, although this was not always investigated and not always taken into account. In all countries except Mexico and Venezuela, high beta-hydroxybutyrate (BHB) levels before calving in many cows highlighted the presence of condition loss in late pregnancy, an important potential constraint on productivity and fertility. Fewer cows showed high BHB levels in lactation, whereas change in BCS and weight was more sensitive for measuring negative energy balance. Urea concentrations were low in only small numbers of cows suggesting that dietary protein shortages were not common. Albumin values were low mainly in cows where globulin values were high and, hence, did not generally provide additional information. The exception was in China where pregnant yaks over winter had high BHB and low albumin values, suggesting that they were seriously underfed. This observation stimulated a successful nutritional intervention in the following winter. Inorganic phosphate values were within the reference range in most countries a majority of the time suggesting, contrary to expectation, that this mineral was not commonly a constraint. The use of metabolic profile testing proved valuable in drawing attention to important potential constraints on productivity in dairy cows in tropical and subtropical environments and in confirming those which were not. 相似文献
128.
Graham R. D. McGrann Tracy Yoxall Linda J. Paterson Jeanette M.G. Taylor Ioannis G. Birmpilis Dale R. Walters Neil D. Havis 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(2):447-461
Plant defence elicitors are compounds that can induce host defence responses against plant pathogens and offer a novel strategy for disease management. Disease control by elicitors can be inconsistent and is often dependent on the crop, the variety and the environment. The use of foliar application of defence elicitors to control light leaf spot (LLS) disease caused by Pyrenopeziza brassicae in the brassica crops winter oilseed rape (WOSR) and Brussel sprouts was evaluated in field trials across multiple years. Elicitor responses in WOSR varied between years. Yield benefits were also inconsistent and did not reflect the level of disease control. Results with Brussel sprouts were more consistent although variation between variety, trial site and year were observed. In particular the salicylic acid analog Acibenzolar-S-Methyl, in the commercial product Bion®, demonstrated good disease control across the field trial sites in the early maturing Brussel sprout variety Cobus. Levels of LLS were consistently reduced when Bion® was alternated within a standard fungicide programme, applied as an individual spray or in combination with other defence elicitors. When applied as a root drench or seed soak Bion® also reduced symptom development of the soil-borne brassica disease clubroot, caused by Plasmodiophora brassicae, in WOSR. These results indicate that defence elicitors such as Bion® can be used as an additional disease management tool alongside host resistance and standard fungicide programmes to protect brassica crops. 相似文献
129.
Pretorius A Van Kleef M Van Wyngaardt W Heath J 《Veterinary immunology and immunopathology》2012,146(1):81-86
African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV na?ve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4? cells. In addition to the expected antibody response, an increase in CD8? cells was also detected. Although these CD8? cells may be CTL, the role of these cells in immunity against AHSV still has to be determined. 相似文献
130.
The dog is the natural host of Staphylococcus pseudintermedius. Many research efforts are currently being undertaken to expand our knowledge and understanding of this important canine commensal and opportunistic pathogen. The objective of this review is to summarize the current knowledge of the species, including the latest research outcomes, with emphasis on taxonomy, diagnostics, ecology, epidemiology and pathogenicity. Despite the important taxonomic changes that have occurred over the past few years, the risk of misidentification in canine specimens is low and does not have serious consequences for clinical practice. Staphylococcus pseudintermedius carriage in the dog is more frequent and genetically heterogeneous compared with that of Staphylococcus aureus in man. It appears that these staphylococcal species have evolved separately through adaptation to their respective natural hosts and differ with regard to various aspects concerning ecology, population structure and evolution of antibiotic resistance. Further understanding of the ecology and epidemiology of S. pseudintermedius is hampered by the lack of a standard method for rapid and discriminatory typing and by the limited data available on longitudinal carriage and population structure of meticillin‐susceptible strains. With regard to pathogenicity, it is only now that we are starting to explore the virulence potential of S. pseudintermedius based on genomic and proteomic approaches, and more research is needed to assess the importance of individual virulence factors and the possible existence of hypervirulent strains. 相似文献