全文获取类型
收费全文 | 235篇 |
免费 | 11篇 |
专业分类
林业 | 16篇 |
农学 | 11篇 |
99篇 | |
综合类 | 9篇 |
农作物 | 13篇 |
水产渔业 | 10篇 |
畜牧兽医 | 73篇 |
园艺 | 3篇 |
植物保护 | 12篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 14篇 |
2011年 | 12篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 17篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 15篇 |
2004年 | 23篇 |
2003年 | 13篇 |
2002年 | 16篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1990年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有246条查询结果,搜索用时 15 毫秒
1.
Rosario Preziosi Maria Morini Giuseppe Sarli 《Journal of veterinary diagnostic investigation》2004,16(6):554-561
Thirty-one canine cutaneous masses, diagnosed as mast cell tumors (MCT) by histopathologic analysis, were used to evaluate the immunohistochemical pattern of expression of KIT protein (CD117), a type III tyrosine kinase protein involved in mast cell growth and differentiation. Lesions were graded as I (well differentiated), II (intermediate differentiation), or III (poorly differentiated) according to the following morphologic features: invasiveness, cellularity and cellular morphology, mitotic index, and stromal reaction. Immunohistochemical KIT expression was compared with histologic grade and some histomorphologic features (cell differentiation and nuclear grade) evaluated separately. A possible predictive role of biologic behavior in MCTs for KIT expression was also investigated. Immunohistochemical analysis revealed three different patterns of KIT expression: a cytoplasmic diffuse pattern, a membranous pattern with immunostaining located on the cell surface, and a cytoplasmic perinuclear pattern, where KIT expression was detected in the cytoplasm of the neoplastic mast cells, close to the nucleus. Statistical analysis showed a close relationship between different KIT immunohistochemical patterns and histologic grade (P < 0.00000), cell differentiation (P < 0.00000), and nuclear grade (P < 0.0024). According to Kaplan-Meier-estimated survival curves compared by survival analysis, KIT expression was significantly associated with survival time (P = 0.037) but not cancer-free interval (P = 0.50). Similar to other well-known histomorphological features, KIT expression is a useful parameter of malignancy in cutaneous MCTs. KIT expression also predicted the biological behavior of the tumors in this study. 相似文献
2.
Maribel Abadias Isabel Alegre Josep Usall Rosario Torres Inmaculada Viñas 《Postharvest Biology and Technology》2011,59(3):289-297
The risk of undesirable by-products from chlorine disinfection in fresh-cut industries, together with its limited efficacy, has led to a search for alternative agents. The aim of this study was to test several alternative putative antimicrobial substances to reduce Escherichia coli O157:H7, Salmonella spp. and Listeria spp. populations on fresh-cut apple. Carvacrol, vanillin, peroxyacetic acid, hydrogen peroxide, N-acetyl-l-cysteine and Citrox were selected for their results in in vitro assays against E. coli O157:H7 and Listeria spp., to be tested on fresh-cut apple plugs. Apple flesh was inoculated by dipping in a suspension of a mix of the studied pathogens at 106 cfu mL?1, and then treated with the antimicrobial substances. All treatments were compared to deionized water and a standard sodium hypochlorite treatment (SH, 100 mg L?1, pH 6.5). Pathogen population on apple plugs was monitored for up to 6 days at 10 °C. Bacterial reductions obtained by peroxyacetic acid (80 and 120 mg L?1), vanillin (12 g L?1), hydrogen peroxide (5, 10, 20 mL L?1) and N-acetyl-l-cysteine (5 and 10 g L?1) were similar or higher than reduction obtained by SH. In addition, bacterial populations were maintained at low levels throughout storage. No cells of any of the pathogens were detected in the peroxyacetic acid, hydrogen peroxide, Citrox and SH washing solutions after apple treatment. Peroxyacetic acid, hydrogen peroxide and N-acetyl-l-cysteine could be potential disinfectants for the fresh-cut industry as an alternative to chlorine disinfection. However, their effect on sensory quality and effectiveness under commercial processing conditions should be evaluated. 相似文献
3.
This case report describes a case of multiple follicular cysts in a 4-year-old Spanish purebred stallion. The lesions ranged in size from 0.5 to 3 cm in diameter, and were firm, well circumscribed and nonpruritic. They developed over a 2-year period with a generalized distribution affecting all body regions. Five nodules were removed and histopathologically corresponded to simple epidermal cysts (infundibular and isthmus-catagen) with squamous epithelium and a keratin filled cavity. Lesions were not evident at birth but their number, early age of detection, slow growth and lack of previous trauma suggested that they were congenital. To the authors' knowledge, this condition has not previously been reported either in young horses or in Spanish purebred horses. 相似文献
4.
Depletion study and estimation of withdrawal periods for florfenicol and florfenicol amine in pacu (Piaractus mesopotamicus) 下载免费PDF全文
Tamires Valim Marques Jonas Augusto Rizzato Paschoal Rafael Simões Coelho Barone José Eurico Possebon Cyrino Susanne Rath 《Aquaculture Research》2018,49(1):111-119
The intensive production of farmed fish is at a global all‐time high, and the control of bacteria proliferation in fish farms requires the frequent use of antimicrobials. This practice raises important environmental concerns related to the emergence of antimicrobial‐resistant bacteria strains. Only a few antimicrobial drugs have been approved for use in aquaculture, one of which is florfenicol. This work studies the depletion and withdrawal period of florfenicol and its main metabolite, florfenicol amine, in pacu (Piaractus mesopotamicus), a neotropical characin widely farmed in the southern hemisphere. Juvenile pacu (average weight of 724 g) were stocked in a closed‐loop laboratory system with controlled water temperature (25.8°C), and were fed for 10 consecutive days with a diet containing an intended dose of 10 mg/florfenicol per kg bw. Muscle and skin tissues were collected at 1, 3, 6, 8, 10, 12 and 16 days post‐treatment, and florfenicol and florfenicol amine were quantified using a validated ultra‐high performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS) method. The limits of quantitation for florfenicol and florfenicol amine were 10 ng/g in muscle and 50 ng/g in skin. Considering a maximum residue limit of 1000 ng/g for the sum of florfenicol and florfenicol amine in muscle with skin in natural proportions a withdrawal period of 5 days (water temperature 25.8°C) or 129 degree days was calculated on the basis of the upper limit of the one‐sided 95% confidence interval for the 99th percentile derived from the residue depletion study. 相似文献
5.
Fernandez-Orozco R Frias J Muñoz R Zielinski H Piskula MK Kozlowska H Vidal-Valverde C 《Journal of agricultural and food chemistry》2007,55(22):8972-8979
The effect of fermentation on the antioxidant compounds [vitamins C and E, total phenolic compounds (TPC), and reduced glutathione (GSH)], and antioxidant capacity [superoxide anion scavenging activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), inhibition of phosphatidylcholine (PC) peroxidation, and Trolox equivalent antioxidant capacity (TEAC)] of soybean (Glycine max cv. Merit) was studied. Fermentation was carried out in solid state in cracked seeds inoculated with Aspergillus oryzae, Rhizopus oryzae, Bacillus subtilis, and Lactobacillus plantarum and in liquid state either in cracked seeds or milled soybean flours fermented naturally by only the microorganisms present in the seeds or by inoculation with L. plantarum. Vitamin C was not detected in the studied samples. Fermentation caused a decrease in vitamin E activity, except when cracked seed was fermented with A. oryzae, R. oryzae, or B. subtilis that increased 31, 30, and 89%, respectively. Fermentation produced an increase in TPC content and did not affect or reduce the GSH content. Fermentation decreased SOD-like activity drastically, while PRTC increased except when it was carried out naturally in cracked seed. TEAC values rose sharply when soybeans were fermented with B. subtilis. Processed soybean extracts inhibited PC peroxidation in comparison with the control assay. On the basis of the results obtained, the relative contributions of vitamin E, TPC, and GSH to antioxidant capacity were calculated and results showed a very high TPC contribution and a low contribution of GSH and vitamin E activity. Optimum results for functional soybean flours were achieved when fermentation was carried out with B. subtilis inoculum. 相似文献
6.
7.
Blanco A Artacho-Pérula E Flores-Acuña R Moyano R Monterde JG 《Veterinary immunology and immunopathology》2003,96(1-2):111-115
Although the beta2 adrenergic agonists have been seen to have important effects on the mechanisms regulating the development and death of T-cells in the thymus, the side-effects on the immune system of anabolic treatments of these substances have hardly been considered. In order to evaluate the effects exerted by the beta2 adrenergic agonist clenbuterol on the thymocyte population, the thymus of eight pigs treated with anabolic doses of this substance was studied by morphometric methods, regarding apoptotic (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL)-positive) and normal (TUNEL-negative) cells. The thymus of another eight pigs fed without clenbuterol served as a control. The clenbuterol treatment had a clear effect on the thymocyte size, decreasing their mean nuclear area. The T-cell apoptosis index was also affected by the clenbuterol, significantly increasing the apoptosis percentage in the treated group with respect to the control. In the light of our results, the clenbuterol induced thymocyte apoptosis throughout the thymus and caused morphometric changes in the thymocyte population, which was in line with the immunosuppressive role attributed to other beta2 adrenergic agonists. 相似文献
8.
Barone G Ziemer LS Shofer FS Steinberg SA 《Journal of the American Veterinary Medical Association》2002,220(10):1499-1502
OBJECTIVE: To determine prevalence of seizures after use of iohexol for myelography and identify associated risk factors in dogs. DESIGN: Retrospective study. ANIMALS: 182 dogs that received iohexol for myelography in 1998. PROCEDURE: Medical records were reviewed for age, breed, sex, weight, dose and total volume of iohexol, injection site, number of injections, lesion type and location, total duration of anesthesia, duration from time of iohexol injection to recovery, presence and number of seizures, and whether surgery followed the myelogram. RESULTS: 39 (21.4%) dogs had at least 1 generalized seizure during or after myelography. Injection site was strongly associated with prevalence of seizures, and risk of seizure was significantly higher after cerebellomedullary injections, compared with lumbar injections. Mean total volume of iohexol administered to dogs that had seizures was significantly higher, compared with that administered to dogs that did not have seizures, although dosage did not differ between groups. Weight was significantly correlated with risk of seizure, and dogs that weighed > 20 kg (44 lb) had higher prevalence of seizures than dogs that weighed < 20 kg. CONCLUSIONS AND CLINICAL RELEVANCE: It is preferential to administer iohexol via the L5-6 intervertebral space to minimize the risk of seizures. Higher prevalence of seizures in large dogs, compared with smaller dogs, may be caused by administration of larger total volumes of contrast agent per volume of CSF. 相似文献
9.
10.
The reaction of 2,4-decadienal and methyl 13-oxooctadeca-9,11-dienoate with phenylalanine was studied to determine if alkadienals and ketodienes are able to produce the Strecker-type degradation of amino acids to the corresponding Strecker aldehydes. When reactions were carried out at 180 degrees C, both carbonyl compounds degraded phenylalanine to phenylacetaldehyde, among other compounds. The yield of the phenylacetaldehyde produced depended on the reaction pH and increased linearly with both the amount of the lipid and the reaction time. The yield of this conversion was approximately 8% when starting from decadienal and approximately 6% when starting from methyl 13-oxooctadeca-9,11-dienoate, and the reaction rate was lower for the ketone than for the aldehyde. Simultaneous to these reactions, the lipid was converted into pyrrole, pyridine, or aldehyde derivatives as a result of several competitive reactions. In particular, 9-14% of the decadienal was converted into hexanal under the assayed conditions. All these reactions are suggested to be produced as a consequence of the oxidation of the alkadienal or the ketodiene to the corresponding epoxyalkenal or unsaturated epoxyketone, which were identified in the reaction mixtures by GC-MS. All these results suggest that alkadienals and ketodienes, which are quantitatively important secondary lipid oxidation products, can degrade amino acids to their corresponding Strecker aldehydes. Therefore, under appropriate conditions, these products are not final products of the lipid oxidation and can participate in carbonyl-amine reactions analogously to other lipid oxidation products with two oxygenated functions. 相似文献