全文获取类型
收费全文 | 302篇 |
免费 | 8篇 |
国内免费 | 5篇 |
专业分类
林业 | 45篇 |
农学 | 19篇 |
基础科学 | 2篇 |
47篇 | |
综合类 | 15篇 |
农作物 | 31篇 |
水产渔业 | 41篇 |
畜牧兽医 | 74篇 |
园艺 | 14篇 |
植物保护 | 27篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 11篇 |
2021年 | 14篇 |
2020年 | 16篇 |
2019年 | 15篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 10篇 |
2013年 | 22篇 |
2012年 | 19篇 |
2011年 | 29篇 |
2010年 | 21篇 |
2009年 | 14篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 12篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有315条查询结果,搜索用时 656 毫秒
91.
Ali Kadivar Habiballah Rashidzadeh Najmeh Davoodian Hasan Nazari Rohallah Dehghani Tafti Heidar Heidari Khoei Hasan Seidi Samani Jahangir Modaresi Ebrahim Ahmadi 《Reproduction in domestic animals》2021,56(2):287-291
Accurate diagnosis of foetal sex in pregnant mare is helpful for many breeders, both for private or commercial purposes. In this study, in order to pre-natal foetal sexing in equine, we used TaqMan duplex real-time PCR to detect the specific regions of SRY and TSPY genes on extracted cell-free foetal DNA from maternal blood. Peripheral blood samples from 50 pregnant Arabian mares with singleton foetuses were collected. Cell-free foetal DNA was extracted from maternal plasma, and duplex real-time PCR assays were performed with TaqMan probes and primers. Amplification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as control of DNA extraction procedure. From the 50 sampled mares, 28 cases had female and 22 mares had male foetuses. The final results for 46 samples were conclusive, and from them, 43 cases were predicted correctly. Sensitivity, specificity and accuracy of the test were 90.48%, 96% and 93.48%, respectively. In conclusion, a TaqMan duplex real-time PCR was set up to pre-natal detection of foetal sex in equine. The method was fast and decreased the false-positive and false-negative results. The technique can be used as a routine procedure in farms by collecting only a blood sample. 相似文献
92.
Serhat Karaca Sibel Erdoğan Mehtap Güney Cihan Çakmakçı Muammer Sarıbey Aşkın Kor Hasan Ülker 《Animal Science Journal》2021,92(1):e13561
This study examined how inclusion of dried distillers' grains with solubles (DDGS) in finishing lamb diets for different periods affects some physiological indicators and meat quality. A total of 40 male lambs were divided into four groups according to feeding regimen during the 120-day finishing period as follows: C120: no DDGS included in diet for 120 days; D120: DDGS included in diet for 120 days; D75: no DDGS included in diet for 45 days + DDGS included in diet for 75 days; D45: no DDGS included in diet for 75 days + DDGS included in diet for 45 days. Dietary inclusion rate of DDGS was 27.5%. Fattening performance and rumen parameters were not affected by treatment. Feeding regimens had no significant effect on meat quality except the instrumental tenderness and juiciness score. DDGS fed lambs had higher level of total trans fatty acids and n-6/n-3 ratio in meat. 10t-C18:1, 11t-C18:1 and 9c,11t conjugated linoleic acid contents of adipose tissue were higher in all the DDGS groups compared with C120 lambs (p < .001). These results suggest that soybean meal can be replaced with corn DDGS in lamb diets for up to 120 days during the finishing period with no adverse effects on some physiological response feedlot performance and meat quality. 相似文献
93.
M. Hasan F. Seyis A. G. Badani J. Pons-Kühnemann W. Friedt W. Lühs R. J. Snowdon 《Genetic Resources and Crop Evolution》2006,53(4):793-802
Genetic diversity throughout the rapeseed (Brassica napus ssp. napus) primary gene pool was examined by obtaining detailed molecular genetic information at simple sequence repeat (SSR) loci
for a broad range of winter and spring oilseed, fodder and leaf rape gene bank accessions. The plant material investigated
was selected from a preliminary B. napus core collection developed from European gene bank material, and was intended to cover as broadly as possible the diversity
present in the species, excluding swedes (B. napus ssp. napobrassica (L.) Hanelt). A set of 96 genotypes was characterised using publicly available mapped SSR markers spread over the B. napus genome. Allelic information from 30 SSR primer combinations amplifying 220 alleles at 51 polymorphic loci provided unique
genetic fingerprints for all genotypes. UPGMA clustering enabled identification of four general groups with increasing genetic
diversity as follows (1) spring oilseed and fodder; (2) winter oilseed; (3) winter fodder; (4) vegetable genotypes. The most
extreme allelic variation was observed in a spring kale from the United Kingdom and a Japanese spring vegetable genotype,
and two winter rape accessions from Korea and Japan, respectively. Unexpectedly the next most distinct genotypes were two
old winter oilseed varieties from Germany and Ukraine, respectively. A number of other accessions were also found to be genetically
distinct from the other material of the same type. The molecular genetic information gained enables the identification of
untapped genetic variability for rapeseed breeding and is potentially interesting with respect to increasing heterosis in
oilseed rape hybrids. 相似文献
94.
Kara Emine Erman Pirlak Uğur Özdılek Hasan Göksel 《Water, air, and soil pollution》2004,153(1-4):173-186
Water, Air, &; Soil Pollution - The Province of Ni?de, located in central Anatolia, supplies approximately 25% of the total potato production in Turkey. In order to investigate selected... 相似文献
95.
Alaa G. M. Osman Imam A. Mekkawy Johan Verreth Frank Kirschbaum 《Fish physiology and biochemistry》2007,33(1):1-13
Glucose-6-phosphate dehydrogenase (G6PDH), lactate dehydrogenase (LDH) and pyruvate kinase (PK) are key metabolic enzymes.
G6PDH has been used as a biomarker of pollution-induced carcinogenesis in fish. LDH has been used as marker of lesions in
toxicology and clinical chemistry, and PK catalyses the conversion of phosphoenol pyruvate to pyruvate, with regeneration
of ATP. The effect of different concentrations of lead nitrate on the activity of these enzymes in two different early ontogenetic
stages (embryonic and free embryonic stage) of the African catfish Clarias gariepinus was investigated. Embryo homogenates were used for measurements of G6PDH, LDH and PK activity spectrophotometrically at 340 nm
and 25°C. The ontogenetic variations of the three enzymes during early ontogeny, from the 30 h to the 168 h post-fertilisation
stage (PFS) (beginning of exogenous feeding), were studied. There was a significant decrease in activities of all three enzymes
from 30 h-PFS to 96 h-PFS, followed by a significant increase in G6PDH and LDH. PK showed insignificant fluctuations in activity.
Different patterns of enzyme activities were recorded due to exposure to different lead nitrate concentrations (100 μg/l,
300 μg/l and 500 μg/l). In the pre-hatching stage (30 h-PFS) the activity of the three enzymes increased at exposure to 100 μg/l
lead nitrate and then decreased with increasing dose. In the post-hatching stages (48 h-PFS–168 h-PFS) G6PDH activity increased
and LDH activity decreased with increasing lead concentrations. Unlike G6PDH and LDH, the PK enzyme fluctuated during the
post-hatching stages and did not reveal a specific trend of response (increase or decrease) with increasing lead concentrations.
Therefore, the measurement of G6PDH and LDH activities, but not PK activity, could be useful biomarkers of intoxication to
reveal the embryotoxic potential of lead nitrate in fish embryos. The post-hatching stages of the African catfish are more
sensitive than the pre-hatching stage (30 h-PFS) is, probably due to the protective capacity provided by the hardened chorion.
The interaction and the main effects of age and lead doses were found to be highly significant, referring to the great impact
of lead on these enzyme systems with increasing early development. 相似文献
96.
97.
Hasan B Faruque R Drobni M Waldenström J Sadique A Ahmed KU Islam Z Parvez MB Olsen B Alam M 《Avian diseases》2011,55(4):689-692
Antibiotic resistance in avian bacterial pathogens is a common problem in the Bangladesh poultry industry. The aim of the present study was to provide information on the present status of antibiotic resistance patterns in avian pathogenic Escherichia coli in Bangladesh. Of 279 dead or sick poultry of different ages, 101 pathogenic E coli strains isolated from broilers and layer hens with colibacillosis infections were screened to determine phenotypic expression of antimicrobial resistance against 13 antibiotics used in both veterinary and human medicine in Bangladesh. Of 101 pathogenic E. coli isolates, more than 55% were resistant to at least one or more of the tested compounds, and 36.6% of the isolates showed multiple-drug-resistant phenotypes. The most common resistances observed were against tetracycline (45.5%), trimethoprim-sulphamethoxazole (26.7%), nalidixic acid (25.7%), ampicillin (25.7%), and streptomycin (20.8%). Resistance to ciprofloxacin (12.9%), chlormaphenicol (8.9%), nitrofurantoin (2%), and gentamicin (2%) was also observed, and none of the isolates were resistant to tigecycline as well as extended spectrum beta-lactamase (ESBL) producers. One isolate was resistant to cefuroxime (1%), cefadroxil (1%), and mecillinam (1%) but was not an ESBL producer. Resistance rates, although significant in Bangladeshi isolates, were found to be lower than those reported for avian isolates from the Republic of Korea and clinical, avian, and environmental isolates from Bangladesh. The high level of antibiotic resistance in avian pathogens from Bangladesh is worrisome and indicates that widespread use of antibiotics as feed additives for growth promotion and disease prevention could have negative implications for human and animal health and the environment. 相似文献
98.
Kul O Atmaca HT Deniz A Süer C 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(9-10):386-389
This report deals with a case of cutaneous toxoplasmosis in a 2 year-old female Angora cat. Cutaneous lesions were characterized by prescapular ulcers and hyperemic nodules in the skin of the inguinal and dorsosacral regions. A skin biopsy sample was collected from the lesioned area and processed for histopathologic examination and immunoperoxidase test using Toxoplasma gondii and Neospora caninum specific antibodies. Toxoplasma gondii immunopositive reactions were detected in keratinocytes and dermal macrophages while no immunoreactivity was detected for N. caninum. The case of cutaneous toxoplasmosis was further confirmed by PCR analysis using T. gondii B1 gene-specific primers. In conclusion, we report the first case of cutaneous toxoplasmosis in Angora cats. 相似文献
99.
Hatice Cicek Hasan Cicek Mustafa Eser Murat Tandogan Hıfzı Oguz Sarımehmetoglu 《Tropical animal health and production》2011,43(1):17-20
This study was carried out to investigate the prevalence and economic losses due to in cattle of hypodermosis between May
2008 and April 2009 in Afyonkarahisar province of Turkey. A total of 6,598 cattle—3,498 in pasture and 3,100 in slaughterhouse—were
examined for hypodermosis. One hundred ninety-five out of 6,598 cattle (2.96%) were found positive. Concerning this infestation
rate, the prevalence of hypodermosis in field was 5.3%, whereas the prevalence was 0.3% in slaughter house. Hypoderma bovis and Hypoderma lineatum were recorded in slaughter house. First-stage Hypoderma spp. larvae weren’t found in cattle organs in slaughterhouse. The annual economic loss on skins is estimated to be about
18,288 TL (currency exchange rate is 1 USD:1.499 TL). 相似文献
100.
El-Nahla SM Imam HM Moussa EA Elsayed AK Abbott LC 《Anatomia, histologia, embryologia》2011,40(3):169-186
With 14 figures and 3 tables SUMMARY: Each adrenal gland consisted of cortex and medulla that developed from different embryological origins and presented different cellular organization. One hundred male or female camel embryos or fetuses with crown vertebral rump lengths (CVRL) that ranged from 0.8 to 117 cm were examined. The adrenal cortex, which is derived from intermediate mesoderm, was first observed in the 0.8-cm CVRL camel embryo. The adrenal cortex initially was combined with the gonad as a thickened region of proliferating cells derived from splanchnic intermediate mesoderm. Adrenocortical tissue was first separated from the gonadal tissue in the 2-cm CVRL camel fetus and was observed as a separate dorso-medial mass of cells. At 2.5-cm CVRL, the adrenocortical tissue was surrounded by a capsule of undifferentiated mesenchymal cells, except at its proximal pole, where an invagination was located through which chromaffinoblast cells entered the cortex. The chromaffinoblast cells migrated from the neural crest to form the medulla of the developing adrenal gland. In the 3.5-cm CVRL camel fetus, the adrenocortical cells differentiated into two layers: the inner fetal cortex and the outer definitive cortex. As development proceeded, the fetal cortex degenerated and the definitive cortex formed the zona glomerulosa and zona fasciculata. The zona reticularis did not form until the end of gestation. During prenatal life, the adrenal medulla was much thicker than the cortex. 相似文献