首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   48篇
  免费   12篇
  国内免费   7篇
农学   3篇
综合类   11篇
农作物   1篇
水产渔业   2篇
畜牧兽医   49篇
园艺   1篇
  2023年   2篇
  2022年   6篇
  2021年   4篇
  2019年   6篇
  2018年   1篇
  2017年   5篇
  2016年   5篇
  2015年   4篇
  2014年   4篇
  2013年   2篇
  2012年   2篇
  2011年   1篇
  2010年   5篇
  2008年   2篇
  2007年   2篇
  2005年   4篇
  2004年   2篇
  2003年   2篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1997年   1篇
  1995年   1篇
  1992年   1篇
  1991年   1篇
  1980年   1篇
排序方式: 共有67条查询结果,搜索用时 15 毫秒
21.
目的:探讨金线莲多糖对免疫抑制小鼠脾淋巴细胞增殖及免疫器官的影响。方法:按大、中、小剂量给小鼠灌胃金线莲多糖,腹腔注射环磷酰胺(CY)建立免疫抑制模型;测定小鼠体重及胸腺、脾脏重量,计算胸腺、脾指数;采用MTT法检测脾淋巴细胞的增殖。结果:3个金线莲多糖剂量组小鼠的体重及免疫器官指数均低于空白组而高于模型组,脾淋巴细胞增殖均显著(P〈O.05)高于模型组。结论:金线莲多糖能提高免疫抑制小鼠体重及免疫器官指数,促进脾淋巴细胞增殖。  相似文献   
22.
A study was undertaken to investigate the effect of immunosuppression by cyclophosphamide or methylprednisolone on the clinicopathological alterations in respiratory absidiosis in rabbits. Infected rabbits showed respiratory distress that was more severe in immunosuppressed groups. Leukocytosis due to neutrophilia was observed in the non-immunosuppressed group in the initial stages, whereas leukopenia was observed in both the immunosuppressed groups initially, owing to polymorphopenia in the cyclophosphamide-treated group and to lymphopenia in the methylprednisolone-treated group, followed by leukocytosis in both groups. Total serum proteins increased significantly in the non-immunosuppressed group but were significantly decreased in the immunosuppressed groups. Serum creatinine increased significantly in all the infected groups from 20 days post inoculation (DPI) onwards. Blood urea nitrogen increased significantly in the initial stages only in the methylprednisolone-treated group. AST and ALT also showed significant increases in the infected animals. Total serum immunoglobulins and circulating immune complexes increased gradually in all three infected groups, except for an initial significant drop in the immunosuppressed rabbits. Re-isolation of fungus was only achieved from the lungs of infected rabbits up to 15 DPI in the non-immunosuppressed group and 30 DPI in the immunosuppressed groups. Pathological lesions in all the infected groups were found mainly in the lungs and consisted of pyogranulomas. The lesions were most severe in the cyclophosphamide-treated group and least severe in the non-immunosuppressed group.  相似文献   
23.
为探讨环磷酰胺(CYP)对大鳞副泥鳅(Paramisgurnus dabryanus)的免疫抑制作用,分别以100、200、300mg/kg体重的剂量对大鳞副泥鳅腹腔注射CYP,对照组注射等量的0.85%灭菌生理盐水,在注射CYP后第8天,测定泥鳅的红细胞数(RBC),白细胞数(WBC),血清一氧化氮(NO)含量,补体C3含量,溶菌酶(LSZ),酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、肝胰脏超氧化物岐化酶(SOD)活性及丙二醛(MDA)含量。结果显示:与对照组相比,300 mg/kg组的RBC、WBC、血清LSZ、ACP、AKP活性及补体C3含量分别显著降低73.5%、81.0%、52.2%、29.0%、47.9%和48.6%(P0.05);血清NO含量和肝胰脏MDA含量分别显著增加144.0%和50.8%(P0.05);肝胰脏SOD活性降低不显著(P0.05)。由此表明,CYP可抑制大鳞副泥鳅的免疫功能。  相似文献   
24.
研究玉竹多糖和板蓝根多糖对环磷酰胺致雏鸡免疫抑制的调节作用。将120只1日龄雏鸡随机分成6组,分别为空白对照组、玉竹多糖对照组、玉竹多糖调节组、板蓝根多糖对照组、板蓝根多糖调节组、免疫抑制对照组,除空白对照组外,其余各组在7日龄时饮水免疫鸡新城疫、传染性支气管炎二联活疫苗(LaSota株+H120株)。测定免疫后不同阶段雏鸡新城疫疫苗抗体滴度、血清IgA含量和外周淋巴细胞OD570 nm值,以及脾脏指数和法氏囊指数。结果显示,环磷酰胺造模后,可见环磷酰胺抑制对照组抗体滴度持续处于较低的状态,血清IgA含量较低,外周淋巴细胞增殖受抑制,免疫器官指数较低;在免疫后14 d、21 d、28 d和35 d,玉竹多糖调节组和板蓝根多糖调节组血清抗体滴度显著高于免疫抑制对照组(P<0.05);在免疫后21d、35 d,玉竹多糖调节组和板蓝根多糖调节组血清IgA含量、外周淋巴细胞OD570 nm值和免疫器官指数显著高于免疫抑制对照组(P<0.05)。本试验结果表明,玉竹多糖和板蓝根多糖对环磷酰胺造模形成免疫抑制雏鸡免疫系统具有调节功能,可解除免疫抑制,使免疫系统恢复至正常水平,能够提高雏鸡新城疫疫苗抗体滴度、血清IgA含量,增强外周淋巴细胞增殖。  相似文献   
25.
为了探讨新疆石河子南山地区牧草绢蒿对正常小鼠和环磷酰胺所致免疫低下小鼠的免疫调节作用,采用脾脏系数测定法、脾脏淋巴细胞ANAE染色法、姬姆萨-瑞特氏染色法、MTT法、抗支原体抗体ELISA法及大肠杆菌攻毒试验分别对小鼠脾脏指数、T淋巴细胞数量、巨噬细胞吞噬活性、脾脏淋巴细胞增殖、抗体分泌功能及抗致病性大肠杆菌感染能力等指标进行研究。结果表明,高、低浓度的绢蒿水煎剂均能不同程度提高免疫低下小鼠和正常小鼠的T淋巴细胞数量及腹腔巨噬细胞吞噬功能;高、低浓度的绢蒿水煎剂均能不同程度提高正常小鼠的脾脏淋巴细胞增殖能力;低浓度的绢蒿水煎剂能提高正常小鼠对大肠杆菌的抗感染能力;高浓度的绢蒿水煎剂能下调免疫低下小鼠和正常小鼠的脾脏指数,下调正常小鼠的血清抗体效价。提示,绢蒿水煎剂对免疫低下小鼠有一定的增强免疫作用,对正常小鼠具有双向免疫调节作用。本研究结果为进一步开发绢蒿免疫调节剂提供了依据。  相似文献   
26.
龚蕾  郎茜  马莎  陈翠  周正宏 《中国畜牧兽医》2021,48(10):3787-3794
试验旨在研究环磷酰胺不同剂量、不同给药次数对建立的小鼠免疫抑制模型免疫指标变化的影响。选择7周龄雄性昆明小鼠200只,随机均分为5组:对照组(生理盐水组,0 mg/g环磷酰胺)、环磷酰胺3次注射低剂量(0.04 mg/g)和高剂量(0.08 mg/g)组、环磷酰胺1次注射低剂量(0.10 mg/g)和高剂量(0.16 mg/g)组。3次注射组在试验第1天按照给定剂量腹腔注射环磷酰胺,连续注射3 d;对照组按照相同方法每天腹腔注射等体积生理盐水;1次注射组仅在试验第1天按照给定剂量腹腔注射环磷酰胺1次。试验期间每天对小鼠称重,在试验的第1、2、4、6、9、10、11天从各组分别选取8只小鼠采取尾静脉血检测血常规,并在试验的第1、4、6、9、11天从各组分别选取8只小鼠处死,测定股骨骨髓有核细胞、胸腺指数、脾脏指数等指标。结果表明,所有剂量环磷酰胺均可成功建立免疫抑制模型。抑制效果上,0.08 mg/g 3次注射对白细胞、骨髓有核细胞、体重增重、脾脏、胸腺的免疫抑制效果最好,0.16 mg/g 1次注射对红细胞免疫抑制效果最好。抑制周期上,环磷酰胺对白细胞、骨髓有核细胞、脾脏免疫抑制周期较短,对红细胞、胸腺的免疫抑制周期较长;1次注射均较3次注射更早且显著地出现白细胞免疫亢进,而脾脏免疫情况则刚好相反。综上,环磷酰胺不同给药剂量及给药次数对动物不同免疫部位的免疫状态及免疫抑制周期均会产生不同的影响。本研究可为药理试验中针对不同免疫指标进行观测时提供适当的检测剂量及检测时间参考。  相似文献   
27.
蕨麻多糖对小鼠免疫功能的影响   总被引:8,自引:0,他引:8  
用环磷酰胺作为免疫抑制剂小鼠腹腔注射(100mg/kg)建立免疫抑制模型,观察不同剂量蕨麻多糖(50、100、200、400mg/kg)对小鼠脾脏指数、胸腺指数及血清溶菌酶活力的影响.结果显示,蕨麻多糖能明显提高正常小鼠脾脏指数、胸腺指数及免疫抑制小鼠脾脏指数;增强正常小鼠和免疫抑制小鼠血清溶菌酶活力,尤其在免疫抑制状态下,增强作用更明显.表明该多糖可对抗Cy所致的免疫抑制,明显地增强小鼠免疫功能.  相似文献   
28.
Four groups of lambs, about 6 months old, were given 4 different immunosuppressiva (prednisolone, cyclophosphamide, niridazole and gestagene hormones), 1 substance to each group. After this treatment the 4 groups together with a 5th group of the same size, were infected with Listeria monocytogenes (Lm).None of the animals developed clinical listeric encephalitis. The level of antibodies differed between the groups. The group not given any immun osuppressivum reached the highest antibody titres, the group given gestagene hormones had the lowest titres and the other groups ranged somewhere inbetween. All the groups except the group treated with niridazole had a strong delayed hypersensitivity reaction against Lm. The effects of the treatment upon some blood components are also described.Further studies are necessary to establish the effect of various immunosuppressiva, especially gestagene hormones.  相似文献   
29.
The effects of dietary nucleotides on thymocyte DNA damages induced by cyclophosphamide (CP) in mice were examined. First, phase I experiment was conducted to determine the optimal timing of detecting thymocyte DNA damages induced by CP (150 mg/kg body weight) in mice. Thymocyte DNA damages was determined at 6, 12, 18, 24 h by single-cell gel electrophosphoresis assay (comet assay) after intraperitoneal injection of CP. The levels of DNA damage at 6, 12, 18, 24 h were all significantly higher than that of the control group (p < 0.01). The highest level of DNA damage appeared at 18 h and then decreased at 24 h. Therefore, 18 h was selected to determine DNA damages induced by CP in subsequent experiments. In phase II experiment, 30 male KunMing mice were divided into three treatments: negative control (NC), positive control (PC) and nucleotides group (NG). Mice in NC and PC were fed nucleotide-free diet, and mice in NG were fed nucleotide-supplemented diet (supplemented with 0.25% nucleotides, a mixture containing equal amounts of AMP, CMP, GMP and UMP). Mice in PC and NG groups were injected with CP (150 mg/kg body weight) at 21 days. DNA damage in thymocytes was evaluated at 18 h after CP treatment. The results indicate that dietary nucleotides do not affect the weights of the thymus and the spleen, or their organ indices (p > 0.05), but significantly decrease the percentage of comet cells and comet tail sizes (p < 0.01). This study demonstrates that dietary nucleotides could reduce the level of thymocyte DNA damage induced by CP in mice.  相似文献   
30.
Low‐dose cyclophosphamide (CyLD) has shown promise in the treatment of several cancers; however, the effect of CyLD on canine oral malignant melanoma has never been explored. In this study, we investigated the effects of CyLD with or without piroxicam (Px) on tumour neovascularization and vascular normalization in a canine oral malignant melanoma‐xenografted mice model. After treatment with CyLD, Px or a combination of both (CyPx), the growth of the tumour in the treatment groups was significantly suppressed compared to the control group at 30 days of treatment. Proliferation index was also significantly reduced by all treatments, only CyPx significantly lowered microvessel density and vascular endothelial growth factor (VEGF) levels. Additionally, CyLD significantly reduced the proportion of normal vessels and caused an imbalance between VEGF and thrombospondin‐1. These results suggested that CyPx has potent anti‐angiogenic effects in terms of both the number and quality of blood vessels in xenografted canine oral malignant melanoma.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号