全文获取类型
收费全文 | 486篇 |
免费 | 21篇 |
国内免费 | 12篇 |
专业分类
林业 | 6篇 |
农学 | 4篇 |
6篇 | |
综合类 | 89篇 |
农作物 | 13篇 |
水产渔业 | 23篇 |
畜牧兽医 | 186篇 |
园艺 | 177篇 |
植物保护 | 15篇 |
出版年
2024年 | 3篇 |
2023年 | 4篇 |
2022年 | 12篇 |
2021年 | 7篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 5篇 |
2017年 | 18篇 |
2016年 | 19篇 |
2015年 | 14篇 |
2014年 | 28篇 |
2013年 | 40篇 |
2012年 | 33篇 |
2011年 | 42篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 35篇 |
2007年 | 50篇 |
2006年 | 19篇 |
2005年 | 13篇 |
2004年 | 24篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有519条查询结果,搜索用时 843 毫秒
291.
DENG Xiao-geng SONG Er-wei MIN Jun ZHANG Jie CHEN Lun ZENG Bing-sheng FANG Tian-ling CHEN Ji-sheng 《园艺学报》2007,23(7):1322-1325
AIM: To study the proliferation, differentiation and the capacity of forming teratomas of ESC-derived hepatic stem cells in mouse pre-treated with retrorsine and 70% partial hepatotomy. METHODS: The ESC-derived hepatic stem cells, labelled with CFDA SE, were transplanted into BALB/c mouse liver. The distribution, incorperation and proliferation of transplanted cells were observed under fluorescent microscopy. Hepatic function was assayed by detecting albumin level in serum. The situation of forming teratomas in vivo was also evaluated.RESULTS: 1 week post-transplantation, some scattered region was green under fluorescent microscopy. The aera of green region increased apparently in 2 weeks, and cord-like structure was observed. Immunofluorescent staining of albumin demonstrated some positve cells, but there was no significant difference for albumin level in serum (P>0.05). No teratoma was formed in the experimental group, while a large teratoma was observed in control group in 6 weeks post-transplantation.CONCLUSION: The ESC-derived hepatic stem cells are normally incorporated into mouse liver parenchymal structure, proliferate and differentiate further in vivo and possess some hepatic functions without forming teratomas. 相似文献
292.
AIM:To evaluate the anti-angiogenesis effect of interferon-α (IFN-α) on cultured human umbilical vein endothelial cells(HUVECs) and human hepatocellular carcinoma (HCC) bearing nude mouse.METHODS:Anti-proliferation test,MTT test,tube-formation test,migration test on cultured HUVECs were employed and the tumor volume and microvascular desity (MVD) of IFN-α treated human hepatoma cell line (HuH7) were meassured. RESULTS:IFN-α displayed apparent inhibitory effects on cultured HUVECs in anti-proliferation test,MTT test,tube-formation test,migration test,and the tumor diameter and MVD in IFN-α treated HuH7 inoculated nude mouse group were significantly less than those in PBS treated HuH7 inoculated nude mouse group.CONCLUSION: IFN-α inhibits tumor growth through anti-angiogenesis. 相似文献
293.
Molecular cloning and tissue expression of chicken AdipoR1 and AdipoR2 complementary deoxyribonucleic acids 总被引:3,自引:0,他引:3
AdipoR1 and AdipoR2 belong to a novel class of transmembrane receptors that mediate the effects of adiponectin. We have cloned the chicken AdipoR1 and AdipoR2 complementary deoxyribonucleic acids (cDNA) and determined their expression in various tissues. We also investigated the effect of feed deprivation on the expression of AdipoR1 or AdipoR2 mRNA in the chicken diencephalon, liver, anterior pituitary gland, and adipose tissue. The chicken AdipoR1 and AdipoR2 cDNA sequences were 76-83% identical to the respective mammalian sequences. A hydrophobicity analysis of the deduced amino acid sequences of chicken AdipoR1/AdipoR2 revealed seven distinct hydrophobic regions representing seven transmembrane domains. By RT-PCR, we detected AdipoR1 and AdipoR2 mRNA in adipose tissue, liver, anterior pituitary gland, diencephalon, skeletal muscle, kidney, spleen, ovary, and blood. AdipoR1 or AdipoR2 mRNA expression in various tissues was quantified by real-time quantitative PCR, and AdipoR1 mRNA expression was the highest in skeletal muscle, adipose tissue and diencephalon, followed by kidney, ovary, liver, anterior pituitary gland, and spleen. AdipoR2 mRNA expression was the highest in adipose tissue followed by skeletal muscle, liver, ovary, diencephalon, anterior pituitary gland, kidney, and spleen. We also found that a 48 h feed deprivation significantly decreased AdipoR1 mRNA quantity in the chicken pituitary gland, while AdipoR2 mRNA quantity was significantly increased in adipose tissue (P<0.05). We conclude that the AdipoR1 and AdipoR2 genes are ubiquitously expressed in chicken tissues and that their expression is altered by feed deprivation in the anterior pituitary gland and adipose tissue. 相似文献
294.
Opisthorchiid eggs were found in 6 out of 27 (22%) huskies while an ELISA detected antibodies against Opisthorchis felineus and Metorchis bilis in 24 (89%) and 25 (93%) sera taken from these dogs, respectively. All dogs showed an increased activity of glutamate dehydrogenase while aspartate aminotransferase was normal in all samples. Ten weeks after treatment with praziquantel no fluke eggs were found in the faeces from any animal and antibody titres dropped in all animals. 相似文献
295.
Kalaitzakis E Roubies N Panousis N Pourliotis K Kaldrymidou E Karatzias H 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(4):835-845
BACKGROUND: Fatty change of the liver (FCL) is very common in dairy cattle periparturiently. Many laboratory methods have been implicated in order to assist the diagnosis. HYPOTHESIS: To investigate whether FCL in dairy cattle could be evaluated by assessment of ornithine carbamoyl transferase (OCT) by means of an assay modified for bovine serum, other enzyme activity, serum bile acids (SBA) concentration, or other biochemical constituents. ANIMALS: A total of 187 dairy cattle were included: 106 were suspected to have liver dysfunction and were examined after referral by veterinarians; 70 were clinically healthy with mild FCL; and 11 were clinically healthy without FCL. METHODS: Blood and liver biopsy samples were obtained after clinical examination. Histologic examination by light microscopy and classification of samples according to the severity of FCL was done, and total lipid and triglyceride concentration was measured. In serum, OCT, aspartate aminotransferase (AST), alanine aminotransferase (ALT), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GDH), alkaline phosphatase (ALP), and gamma-glutamyltransferase (gamma-GT) activity as well as SBA, glucose, ketones, total bilirubin (tBIL), and nonesterified fatty acids (NEFA) concentration were measured. RESULTS: OCT and AST activity and tBIL concentration correlate well with the degree of FCL. SBA concentration does not contribute well to FCL diagnosis. The majority of FCL cases appeared within the first 21 days-in-milk (DIM). The majority of moderate-to-severe and severe FCL cases arose in the first 7 DIM. CONCLUSIONS AND CLINICAL IMPORTANCE: Except for OCT, AST, and tBIL, none of the biochemical tests used, including SBA, had sufficient discriminatory power to differentiate reliably between mild and severe FCL because of poor sensitivity. A weak correlation between clinical signs and the extent of FCL was evident. 相似文献
296.
Liping Zhu Jianping Wang Xuemei Ding Shiping Bai Qiufeng Zeng Yue Xuan Gregory S. Fraley Keying Zhang 《动物营养(英文)》2021,7(4):1258-1270
Sinapine derived from cruciferous plants could be converted into trimethylamine by intestinal microbiota. Its metabolite, trimethylamine N-oxide (TMAO), is closely linked to increased risk of cardiovascular disease and fat deposition in mammals. Hens fed with rapeseed meal (RSM) suffered from fatty liver hemorrhage syndrome (FLHS). This study was conducted to investigate whether RSM-induced fatty liver is due to TMAO via altering microbiota composition and diversity. At 33 weeks of age, 600 laying hens were randomly divided into 5 treatment groups, namely control and 14% RSM treatment groups (DY5, with 16.2% erucic acid [EA] and 74.66% glucosinolate [Gl] contents; MB1, with 3.50% EA and 43.23% Gl contents; DY6, with 6.7% EA and 22.67% Gl contents; XH3, with 44.60% EA and 132.83% Gl contents) for 8 weeks. Results revealed that 3 hens died due to liver hemorrhage after ingesting 14% RSM diet. The 14% RSM decreased serum low-density lipoprotein cholesterol (LDL-C) content (P < 0.01) while tended to increase serum TMAO content compared to the control group (P = 0.08). The 14% RSM diet increased red oil O optical density (P < 0.01), and increased total cholesterol (TC) and LDL-C content in the liver (P < 0.01, and P < 0.01, respectively). The 14% RSM decreased liver total bile acid (TBA) content compared to the control (P < 0.01). The DY6 had a higher TBA content in the liver than the XH3 (P < 0.01). The 14% RSM decreased mRNA abundance of liver X receptors alpha (LXR-α, P = 0.01), and increased mRNA abundance of sterol response element binding protein 2 (SREBP-2, P = 0.04). Results revealed that the in-feed RSM could alter richness and diversity of cecal microbiota compared to the control (P < 0.05). Liver TC content and serum TMAO showed a negative relationship with Proteobacteria and Actinobacteria (P = 0.04). In conclusion, 14% RSM increased liver TC and induced high liver score of FLHS, which was possibly associated with the altered cecal microbiota composition, increased serum TMAO levels and LXR-α and SREBP-2 expressions. 相似文献
297.
低分子壳聚糖对罗非鱼的肝脂代谢和饲料利用效率的影响研究 总被引:4,自引:0,他引:4
为研究低分子壳聚糖 (SMW Chitosan)对罗非鱼 (Tilapia)肝脏脂肪代谢和饲料利用率的影响效果 ,实验采用单因子浓度梯度法饲养罗非鱼 (体重 1 8 96± 1 2 4g)。 3个月后测定结果表明 ,对照组罗非鱼的肝体比明显高于实验组 ,0 5 0 %低分子壳聚糖实验组罗非鱼的肝体比最小 ;实验组罗非鱼的肝脂含量均显著低于对照组 ,其中含 0 5 0 %低分子壳聚糖组罗非鱼的肝脂含量比对照组下降了2 8 2 4 %;0 5 0 %低分子壳聚糖实验组的饲料系数比对照组下降 2 4 1 0 %。壳聚糖对罗非鱼的特殊增长率也有显著性影响。实验表明 ,一定剂量的低分子壳聚糖能有效促进罗非鱼的肝脂代谢 ,提高罗非鱼的饲料利用能力。 相似文献
298.
Effect of ginsenoside Rb1 on liver cell pyroptosis in hyperlipidemia rats and its possible mechanism
AIM:To discuss the mechanism of ginsenoside Rb1 against liver lipid deposition by observing the effect of ginsenoside Rb1 on liver cell pyroptosis in hyperlipidemia rats. METHODS:Totally 32 healthy SPF rats were randomly divided into control group, model group, ginsenoside Rb1 group and simvastatin group. The rats in control group was given the basic feed, while the others were given high-fat diet. The rats in ginsenoside Rb1 group and simvastatin group were given corresponding drugs. The rats in control group and model group were intraperitoneal injected with equal volume of saline. Eight weeks later, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were tested by the automatic biochemistry analyzer. The pathological changes of the liver tissues were observed with HE staining. The protein and mRNA expression levels of pyroptosis-related factors NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were detected by Western blot and RT-qPCR. RESULTS:Compared with control group, the serum levels of TC, TG and LDL-C in model group were increased significantly (P<0.01), and the HDL-C content was decreased significantly (P<0.05). The steatotic liver cells covered the visual field. The mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were increased significantly (P<0.01). Ginsenoside Rb1 significantly decreased the serum levels of TC, TG and LDL-C (P<0.05), and significantly increased the content of HDL-C (P<0.01). Ginsenoside Rb1 also significantly decreased the degree of steatosis, and the number and size of lipid droplets. The mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, IL-18 and GSDMD were decreased significantly (P<0.05 or P<0.01). CONCLUSION:Ginsenoside Rb1 atte-nuates liver injury and inhibits liver lipid deposition in hyperlipidemia rats by reducing the expression of hepatic pyroptosis-related factors. 相似文献
299.
利用Pie Data SC-400型超声扫描仪,对12头临床健康牛进行肝胆超声断层扫描的反复实验。结果:牛肝脏可在右侧第8~12肋间显示,呈均匀的弱回声影像,肝下缘切面轮廓为锐角的楔状图像,肝壁面及脏面整齐、清晰:门静脉和肝静脉能在多数牛的第10~12肋间显示,并可根据其管壁回声强弱等加以分辨;胆囊多在右侧第11或10肋间探到,为边缘光滑整齐、轮廓清晰的类三角形或椭圆形无回声液性暗区。并测定了试验 相似文献
300.
临床研究发现肝硬化患者可出现胰岛素抵抗。针对这一发现,利用四氯化碳毒性肝硬变模型,进一步研究其葡萄糖耐量及血胰岛素水平。研究发现:肝硬变大鼠出现胰岛素抵抗,但肝硬化程度与血糖水平及血中胰岛素水平无明显相关。 相似文献