全文获取类型
收费全文 | 651篇 |
免费 | 35篇 |
国内免费 | 4篇 |
专业分类
林业 | 68篇 |
农学 | 43篇 |
基础科学 | 2篇 |
164篇 | |
综合类 | 41篇 |
农作物 | 64篇 |
水产渔业 | 100篇 |
畜牧兽医 | 134篇 |
园艺 | 13篇 |
植物保护 | 61篇 |
出版年
2023年 | 5篇 |
2022年 | 24篇 |
2021年 | 25篇 |
2020年 | 31篇 |
2019年 | 38篇 |
2018年 | 42篇 |
2017年 | 30篇 |
2016年 | 36篇 |
2015年 | 28篇 |
2014年 | 43篇 |
2013年 | 62篇 |
2012年 | 39篇 |
2011年 | 38篇 |
2010年 | 35篇 |
2009年 | 19篇 |
2008年 | 34篇 |
2007年 | 18篇 |
2006年 | 24篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1960年 | 1篇 |
1957年 | 1篇 |
1914年 | 1篇 |
排序方式: 共有690条查询结果,搜索用时 15 毫秒
1.
J. Rashid D. J. Weiss S. K. Maheswaran M. P. Murtaugh 《Veterinary research communications》1996,20(6):519-531
Local and systemic activation of coagulation is frequently associated with bacterial sepsis. The coagulopathy is due, at least in part, to expression of tissue factor (TF) by monocytes and macrophages. The purpose of this study was to evaluate the expression of procoagulant activity by bovine alveolar macrophages, leukocytes and platelets, and to determine the relative potency of three chemical inhibitors of TF expression (pentoxifylline, retinoic acid, and cyclosporin A). Bovine alveolar macrophages were stimulated with lipopolysaccharide (LPS) derived from Pasteurella haemolytica or recombinant bovine tumour nervous factor (TNF) and dose- and time-dependent effects on TF expression were studied. LPS and TNF induced TF expression in alveolar macrophages and LPS treatment of whole blood induced TF expression in mononuclear cells. Neutrophils and platelets also expressed procoagulant activity, but this activity was not inhibited by anti-bovine TF monoclonal antibody. Pentoxifylline (40 mol/L), retinoic acid (0.01 mmol/L) and cyclosporin A (0.08 mol/L) inhibited TF expression when added concurrently with LPS or TNF, but not when added 4 h after stimulation. TF mRNA was not detected in unstimulated alveolar macrophages by Northern blot analysis. In contrast, exposure to LPS or TNF for 6 h induced marked expression of TF mRNA, which was inhibited by treatment with pentoxifylline, retinoic acid and cyclosporin A. Expression of TNF by alveolar macrophages stimulated with LPS was also inhibited by these compounds. Our results indicate that procoagulant activity expressed by alveolar macrophages and monocytes is associated with expression of TF, whereas procoagulant activity expressed by neutrophils and platelets is not. The concentrations of pentoxifylline and retinoic acid necessary for inhibition of TF expression in vitro may not be achievable in vivo owing to their toxic effects. However, the in vitro concentration of cyclosporin A that inhibited TF expression did not exceed the plasma concentration observed in humans, and therefore may be useful for inhibition of TF expression in vivo.Abbreviations BAL
bronchoalveolar lavage
- LPS
lipopolysaccharide
- cDNA
cloned deoxyribonucleic acid
- cAMP
cyclic adenosine monophosphate
- GAPDH
glyceraldehyde phosphate dehydrogenase
- mRNA
messenger ribonucleic acid
- TF
tissue factor
- TNF
tumour necrosis factor
- DPBS
Dulbecco's phosphate-buffered saline 相似文献
2.
Kifah Jumaah Odhaib Kazeem Dauda Adeyemi Muideen Adewale Ahmed Muhammad Faseleh Jahromi Shokri Jusoh Anjas Asmara Samsudin Abdul Razak Alimon Halimatun Yaakub Awis Qurni Sazili 《Tropical animal health and production》2018,50(5):1011-1023
The objective of this study was to determine the effects of dietary supplementation of Nigella sativa L. seeds, Rosmarinus officinalis L. leaves and their combination on rumen metabolism, nutrient intake and digestibility, growth performance, immune response and blood metabolites in Dorper lambs. Twenty-four entire male Dorper lambs (18.68?±?0.6 kg, 4–5 months old) were randomly assigned to a concentrate mixture containing on a dry matter basis either, no supplement (control, T1), 1% R. officinalis leaves (T2), 1% N. sativa seeds (T3) or 1% R. officinalis leaves +1% N. sativa seeds (T4). The lambs had ad libitum access to urea-treated rice straw (UTRS) and were raised for 90 days. Supplemented lambs had greater (P?< 0.05) intake of DM and UTRS than the control lambs. The T4 lambs had lower (P?< 0.05) nutrient digestibility than those fed other treatments. Total and daily weight gain was greater (P?< 0.05) in T2 lambs than those fed other diets. The T3 and T4 lambs had greater (P?< 0.05) ruminal pH than the T1 and T2 lambs. Supplemented lambs had lower (P?<?0.05) ruminal total volatile fatty acids, acetate, propionate, NH3-N and C18:0 than the control lambs. The T4 lambs had lower (P?< 0.05) population of Fibrobacter succinogenes, Ruminococcus albus, methanogens and total protozoa compared with those fed other diets. Supplemented lambs had lower (P?< 0.05) neutrophils, basophils and serum urea and greater (P?<?0.05) serum IgA and IgG compared with the control lambs. The current results emphasised the variation in the efficacy of medicinal plants in ruminant nutrition. 相似文献
3.
Ibrahim Bala Salisu Ahmad Ali Shahid Amina Yaqoob Ambreen Gul Abdul Qayyum Rao 《Journal of animal physiology and animal nutrition》2021,105(2):354-363
Recent studies have demonstrated a strong relationship between the intestinal microbiota and the host health. As such, consumers are increasingly becoming more concerned about the potential effect of certain foods/feeds, particularly of transgenic origin on the gut microbiota. Although the European Food Safety Authority has recommended in their guidelines, to study the effect of transgenic food/feed on host-microbiota, yet, few studies have focused on the evaluation of such effects mainly due to culturing difficulties. Therefore, this study was intended to evaluate the potential adverse effects of transgenic diet consumption on some specific gut microflora (Lactobacillus group, Bifidobacterium genus, Escherichia coli subgroup and Enterococcus genus) of rabbits. A total of forty-eight rabbits were randomly assigned into four groups and fed a diet containing a variable proportion of transgenic cottonseeds at 0, 20, 30 and 40% inclusion level, respectively. Changes in the specific or total faecal bacterial population were monitored at five different experimental stages (i.e. 0, 45, 90, 135 and 180 days) using both the traditional plate count method (TM) and quantitative real-time PCR (qPCR). No significant differences (p > .05) were observed concerning numbers of specific bacteria or total bacteria between the control and experimental groups, though qPCR showed numerically higher values in terms of 16S rRNA gene copies as compared to the values obtained from TM. However, such numerical differences were biologically insignificant (p > .05). Similarly, no significant variations were noticed in the calculated B/E (log10 copies of Bifidobacterium per g faces/log10 copies of E. coli genome per g faeces) ratios in all the groups. All the ratios were in the range of 1.24 to 1.30 throughout the experiment, indicating a good balance of intestinal microflora and greater resistance to intestinal disorders. It is therefore concluded that feeding transgenic cottonseeds could not adversely affect the gut microflora of rabbits during a long-term study. 相似文献
4.
S. Ali M. Ijaz S. H. Farooqi A. Z. Durrani M. I. Rashid A. Ghaffar A. Ali A. Rehman S. Aslam I. Khan A. Masud K. Mehmood 《Equine Veterinary Education》2021,33(2):75-83
Theileria equi (T. equi) is an obligate intra- and extra-erythrocytic parasite that causes equine theileriosis (ET) in equids. Equine theileriosis is considered a notifiable disease of global significance, a major constraint to the international movement of horses, and endemic in many countries. This disease may be difficult to diagnose, as it can produce variable and nonspecific clinical signs. A cross-sectional study was designed for the molecular characterisation of T. equi and to investigate the associated risk factors of ET accompanied by its consequences on haematological and sero-biochemical parameters. A convenience sampling of 500 blood samples were collected from ET suspect horses from January to December 2017. PCR was performed on all blood samples targeting the 18S rRNA gene of T. equi followed by sequencing; 9% animals tested positive with confirmed sequences. The isolates of this study showed high homology with Cuban, Russian and Brazilian isolates of T. equi (accession numbers KY111762.2 , MG551915.1 and KY952237.1 , respectively). Based on multivariate analysis, the principal risk factors consisted of absence of dogs on the premises and presence of tick infestation. The haemato-biochemical parameters showed a decrease in granulocytes and erythrocytes, and an increase in lymphocytes, monocytes, mean corpuscular volume, mean corpuscular haemoglobin, mean platelet volume, glucose, phosphorus and aspartate aminotransferase in positive horses. This is the first study which identified ET in Punjab (Pakistan) using molecular techniques and risk factors together with the haemato-biochemical variations in horses. 相似文献
5.
6.
Pooja A. R. Yogesh Pandey Meeti Punetha Anju Kala Hari Abdul Samad Gyanendra Singh Vikrant Singh Chouhan 《Reproduction in domestic animals》2023,58(1):60-72
The aim of the present study was to evaluate the expression and localization of lymphangiogenic factors (VEGF-C and VEGF-D), their receptor (VEGFR3) and lymphatic endothelial marker (LYVE1) in buffalo placenta during early pregnancy [EP], and to investigate the functional role of lymphangiogenic growth factors in placental lymphangiogenesis. The mRNA and protein expression of VEGF-C, VEGF-D, their receptor VEGFR3 and LYVE1 showed significant expression in EP1 (29–42 days) and EP2 stages (51–82 days) both in caruncle (maternal part) and cotyledon (foetal part) of the buffalo placenta. Immunoreactivity of VEGF-C, VEGF-D and LYVE1 was observed around the endometrial gland, in lymphatics and trophoblast cells, whereas VEGFR3 mainly localized in lymphatics of the caruncle and cotyledons. Cultured trophoblast cells were treated with VEGF-C/VEGF-D (50, 100 and 150 ng/ml) and combined doses of VEGF-C and VEGF-D (150 ng/ml) each for different time durations (24, 48 and 72 h). The mRNA expression of LYVE1 and PCNA was significantly (p < .001) upregulated with VEGF-C and VEGF-D and combined treatment (@150 ng/ml), as well as significantly downregulating Caspase-3 at 48 and 72 h. Thus, the present study provides evidence that lymphangiogenic factors are expressed in buffalo placental compartments and they may play a significant role in the regulation of placental function in water buffaloes. 相似文献
7.
Suhaila Mohamed Suzana Saka Saleh H. El-Sharkawy Abdul Manaf Ali Sepiah Muid 《Pest management science》1996,47(3):259-264
Ethanolic extracts of 58 Malaysian plants belonging to 24 different families were screened for antifungal activity against seven plant pathogens using the filter paper disc diffusion technique. Two varieties of Piper betle, showed strong activity against all the pathogens tested (Colletotrichum capsici, Fusarium pallidoroseum, Botryodiplodia theobromae, Alternaria alternata, Penicillium citrinum, Phomopsis caricae-papayae and Aspergillus niger), with inhibition diameters significantly (P<0·01) bigger than 2·5 mg ml−1 prochloraz or 10 mg ml−1 clotrimazole. The minimum inhibitory concentrations of the ethanolic extracts of P. betle against these plant pathogens ranged between 0·01 mg ml−1 and 1 mg ml−1. Thirty-four other plants (Kucing gala, Limau batik, Bertholletia excelsa, Bixa orellana, Caesalpinia pulcherrima, Cerbera odollam (fruits and leaves), Colocasia gigantea, Curcuma domestica, Curcuma manga, Derris eliptica, Elephantopus scaber, Eleusine indica, Eugenia polyantha, Euphorbia hirta, Euphorbia tirucalli, Gardenia florida, Hedyotis auricularia, Hibiscus rosa-sinensis, Juniperus chinensis (three varieties), Lawsonia inermis, Lecythis ollaria, Mentha arvensis, Mimusops elengi, Ocimum sanctum, Phyllanthus niruri, Piper nigrum, Piperomia pellucida, Pedilanthus tithymaloides, Polygonum minus, Spondias dulcis, Solanum nigrum, Tinospora tuberculata) showed selective antifungal activity, while 21 species were inactive. 相似文献
8.
Jizzakh Province in Uzbekistan is one of the largest irrigated areas in Central Asia without natural drainage.In combination with aridity,climate change and extensive irrigation practices,this has led to the widespread salinization of agricultural land.The aim of this study was to identify opportunities to improve the reclamation status of the irrigated area and how best to effectively use the water resources in Jizzakh Province based on investigations conducted between 1995 and 2016.A database of field measurements of groundwater levels,mineralization and soil salinity conducted by the provincial Hydro-Geological Reclamation Expeditions was used in the study.The total groundwater mineralization was determined using a portable electric conductometer(Progress 1T)and the chloride concentration was determined using the Mohr method.The soil salinity analyses were conducted by applying two different methods:(1)the extraction and assessment of the soluble salt content,and(2)using an SM-138 conductivity sensor applied to a 1:1 mixture of soil sample and water.The analyses of the monitoring results and the salt balance in the"irrigation water–soil–drainage water"system clearly demonstrated that the condition of the irrigated land in the province was not significantly improved.Under these conditions,the stability of crop yields is achieved mainly through the use of large volumes of fertilizer.However,excess amounts of mineral fertilizers can also cause the salinization of soils.The average groundwater salinization value in most of the irrigated land(75.3%)fluctuated between 1.1 and 5.0 g/L,while the values were less than 1.0 g/L in 13.1%of the land and in the range of 5.1–10.0 g/L in 10.5%of the land.During the period of 1995–2016 the salinization level of the irrigated land in Jizzakh Province increased slightly and the area could be divided into the following classes:no salinity(17.7%of the total area),low salinity(51.3%),moderate salinity(29.0%),and high salinity(2.0%).Detailed studies of the salt balance in irrigated land,the impact of climate change,increased fertilizer use,and repeated remediation leaching on the groundwater level and mineralization should be conducted in the future,due to the possibility of accelerated salinization,fertility decline,and reduced yields of agricultural crops. 相似文献
9.
Md Asaduzzaman Shumpei Iehata Md Moudud Islam Md Abdul Kader Abol‐Munafi Ambok Bolong Daisuke Ikeda Shigeharu Kinoshita 《Aquaculture Nutrition》2019,25(6):1300-1317
This study investigated the effects of sodium alginate supplementation on gut microbiota composition, health parameters, growth performances and growth‐related gene expression of Malaysian mahseer. Five test diets were formulated by supplementing 0%, 0.1%, 0.2%, 0.4% and 0.8% sodium alginate. Triplicate groups of juvenile Tor tambroides (2.19 ± 0.05 g) were stocked in 15 aquaria (20 individuals per aquarium) and fed at 3.0% body weight per day for 60 days. PCoA and UPGMA analysis showed that gut bacterial community were more convergence in higher sodium alginate‐supplemented diets. The percentage of Porphyromonadaceae, Bacteroides, Plesiomonas and Shewanella were substantially higher and Aeromonas, Entomoplasmatales and Prevotellaceae were drastically lower in higher sodium alginate (0.2%–0.8%) diets. Sodium alginate supplementation (≥0.2%) significantly improved the haematocrit value and respiratory burst activity of T. tambroides. Growth performances and feed utilization were significantly higher in 0.2%–0.4% sodium alginate‐supplemented diets. The increased growth rate of T. tambroides was governed by both hyperplastic and hypertrophic muscle growth. Real‐time PCR data demonstrated that most of the growth‐related genes were significantly upregulated in 0.2%–0.4% sodium alginate‐supplemented diet. Finally, it can be concluded that sodium alginate should be supplemented at 2 g/kg in practical fish feed formulation. 相似文献
10.
Effect of high inclusion of rendered animal by‐product ingredients on growth,digestibility and economic performances in climbing perch Anabas testudineus 下载免费PDF全文
Md Sakhawat Hossain Md Abdul Kader Tanwi Dey Nadia Mahjabin Sony Mahbuba Bulbul Shunsuke Koshio 《Aquaculture Research》2017,48(3):931-940
A 70‐day growth trail was conducted to investigate the effects of inclusion of high levels of meat and bone meal (MBM) and protein concentrate (PC) on growth, digestibility and economic performances of climbing perch, Anabas testudineus. Four isonitrogenous diets were formulated by lowering the level of dietary fishmeal protein at 0 (D1, control), 70 (D2), 85 (D3) and 100% (D4) with a mixture of MBM and PC protein (1:1). Triplicate groups of 300 fish (mean weight of 0.80 g) stocked in each 40 m2 pond and fed the respective test diets. A digestibility trial was conducted after the growth trial in indoor glass aquarium. The result showed that growth parameters were significantly decreased (P < 0.05) with fishmeal replacement levels. However, significant differences were not found in feed conversion ratio and survival of fish. No difference was also found in protein efficiency ratio among D1, D2 and D3. Similar to growth parameters, total fish production was highest in D1, intermediate in D2 and D3; and lowest in D4. Apparent digestibility coefficients of dry matter, protein and lipid were highest (P < 0.05) in D1 and lowest in D4. The economic analysis revealed that the benefit cost ratio was ranked by D3 (1.81), D2 (1.71), D1 (1.66) and D4 (1.46) respectively. Upon considering the overall performances and unavailability of finite protein sources, it can be concluded that 70–85% fishmeal could be replaced with a mixture of MBM and PC (1:1) in practical diets for climbing perch. 相似文献