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81.
目的 :通过观察复合益生菌制剂“海生元”各重要组分对实验性肠菌群失调症的治疗效果 ,初步探讨“海生元”纠正肠菌群失调症的疗效机制。方法 :(1)制备SPF BALB/c小鼠肠菌群失调症模型 ;(2 )处理因素分组 :对照组设自然恢复组 (空白对照 )和生理盐水组 (安慰剂对照 )。治疗组按“海生元”制剂中的主要药效学干预成分 (组成成分 )分为 :T9菌液 (双歧杆菌 )组 ,M9菌液 (乳杆菌 )组 ,螺旋藻组 ,组方中药组 ,复方制剂 (“海生元”)组。 (3)比较观察各组疗后第 2、4、6天腹泻症状恢复情况及全程治疗后 (共 6d)肠菌群定量分析结果。结果 :(1)各处理组对模型小鼠腹泻恢复的影响 :疗前各组 10 0 %为Ⅱ~Ⅲ (中~重 )度腹泻。疗后第 2天 ,两对照组Ⅱ~Ⅲ度腹泻为 99%和 93% ,而 5个治疗组依次为 5 3%、5 1%、5 8%、6 7%和4 7% ;疗后第 4天 ,两对照组Ⅱ~Ⅲ度腹泻为 6 5 %和 5 7% ,而 5个治疗组依次为 15 %、2 1%、19%、2 4 %和16 % ;疗后第 6天 ,两对照组和组方中药组Ⅱ度腹泻率分别为 36 %、2 9%和 18% ,其余各组均正常或为I度(轻度 )腹泻。上述 7个处理组大便正常率分别为 2 1%、2 1%、86 %、79%、77%、4 5 %和 89% ,以复方制剂(“海生元”)组最高。 (2 )各处理组肠菌群定量分析 :两对照组疗后第 2、4、6天 ,五  相似文献   
82.
The application of nitrogen fertilisers leads to different ecological problems such as nitrate leaching and the release of nitrogenous gases. N2O is a gas involved in global warming, therefore, agricultural soils can be regarded as a source of global warming. Soil N2O production comes from both the nitrification and denitrification processes. From an ecological viewpoint, using nitrification inhibitors with ammonium based fertilisers may be a potential management strategy to lower the fluxes of N2O, thus decreasing its undesirable effect. In this study, the nitrification inhibitors (NIs) dicyandiamide (DCD) and 3,4-dimethyl pyrazole phosphate (DMPP) have been evaluated as management tools to mitigate N2O emissions from mineral fertilisation and slurry application in grassland systems (experiments 1 and 2), and to assess the phytotoxic effect of these inhibitors per se on clover (experiment 3). Both nitrification inhibitors acted in maintaining soil nitrogen (N) in ammonium form, decreasing cumulative N2O emissions. DCD, but not DMPP, produced phytotoxic effects and yield reduction in white clover. A nutrient imbalance, which led to a senescence process visually observed as chlorosis and necrosis at the border of the leaves, was noted.  相似文献   
83.
目的探讨蒙古黄芪2种不同成分提取物对肠道微生态失调小鼠的调节作用。方法从60只昆明种清洁级小鼠中随机取出10只作为正常对照组,其余50只每天灌胃0.3 g/ml的盐酸林可霉素,每日2次,每次0.3 ml,连续3 d,诱导小鼠肠道微生态失调,正常对照组以等量生理盐水处理。第4天除正常对照组外,所有小鼠均灌胃造成肠道微生态失调模型,将模型小鼠随机分为4组:黄芪多糖组、黄芪皂苷组、丽珠肠乐组和自然恢复组,并灌胃相应浓度药物进行调整治疗,自然恢复组以等量生理盐水处理,连续7 d。结果与自然恢复组相比,黄芪多糖、黄芪皂苷2种药物均能扶植模型小鼠肠道正常菌群生长,提高乙酸含量,降低内毒素水平,有效控制肠杆菌向肝脏的易位(P0.05);黄芪多糖的各项检测指标与其他组相比,差异有显著性,有统计学意义(P0.05)。结论蒙古黄芪不同成分提取物对肠道微生态失调小鼠均具有一定的调节作用,黄芪多糖的疗效可能优于黄芪皂苷。  相似文献   
84.
摘要 目的:探讨龙鹿丸联合来曲唑对多囊卵巢综合征(PCOS)不孕症患者性激素、辅助性T细胞1/辅助性T细胞2(Th1/Th2)免疫失衡和临床结局的影响。方法:选择2020年4月~2023年4月期间在湖南省妇幼保健院接受治疗的135例PCOS不孕症患者。采用双色球法将患者分为对照组和联合组,分别为67例和68例。对照组接受来曲唑治疗,联合组接受龙鹿丸联合来曲唑治疗。对比两组疗效、性激素指标[雌二醇(E2)、促卵泡激素(FSH)、孕酮(P)和黄体生成素(LH)]、Th1/Th2免疫失衡相关指标[干扰素γ(IFN-γ)、白细胞介素4(IL-4)和Th1/Th2]、临床结局和安全性。结果:与对照组相比,联合组临床总有效率更高(P<0.05)。治疗后,联合组E2、FSH、P高于对照组,LH低于对照组(P<0.05)。治疗后,联合组IFN-γ、IL-4、Th1/Th2低于对照组(P<0.05)。联合组的排卵率、妊娠率高于对照组(P<0.05)。两组不良反应发生率组间对比未见差异(P>0.05)。结论:PCOS不孕症患者采用龙鹿丸联合来曲唑治疗,可通过更好地改善性激素水平和提高抗病能力来改善其临床结局。  相似文献   
85.
大气氮沉降影响草地植物物种多样性机制研究综述   总被引:3,自引:0,他引:3  
张世虎  张悦  马晓玉  王聪  马群  杨雪纯  徐婷  马越  郑智 《生态学报》2022,42(4):1252-1261
大气氮沉降对草地生态系统结构和功能的影响已成为全球变化生物学研究重点。大气氮沉降导致草地群落物种多样性降低已成为全球普遍现象,但其生物学机制还不清楚,因此有必要系统梳理大气氮沉降对全球不同草地生态系统的研究结果,以便在氮沉降背景下为我国草地生态系统的研究和管理制定科学决策。系统综述了氮沉降降低草地群落物种多样性的可能机制,主要包括资源竞争排斥、群落更新限制、土壤酸化及其离子毒害、养分失衡、氮素本身的毒害、次生胁迫。氮沉降导致草地物种多样性降低是多种机制综合作用的结果,每种机制在不同时空具有不同的相对贡献。同时,与欧洲酸性土壤草地和美国高草草原相比,我国草地土壤类型和植被属性具有明显差异。因此,应根据我国草地生态系统的特征、不同植物功能利用养分策略,从土壤养分变化、根系养分吸收转运、叶片生理过程等方面的整合研究思路,探讨氮沉降影响我国草地群落物种多样性的生物学机制,为我国草地生态系统的科学管理提供理论依据。  相似文献   
86.
小麦的高温伤害与高温适应   总被引:25,自引:0,他引:25  
小麦叶片经受30分钟高温胁迫后,其电解质伤害性渗漏量(IL)随胁迫温度而增加,两者关系符合指数曲线性质,但超过某一临界温度时,曲线突然变陡,IL的温度系数(Q10)比临界温度之前增加数十倍至数百倍,该临界温度大致相当于或略高于致死温度,麦株经适当高温锻炼后,致死温度及IL达50%时的温度(IT50)均显著增高,但恢复常温后,锻炼效果逐渐解除。  相似文献   
87.
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) and remains a major cause of morbidity and mortality worldwide. In the host's immune response system, T cells play a critical role in mediating protection against Mtb infection, but the role of CD8+ T cells is still controversial. We evaluated the phenotypical characterization and cytotoxic ability of CD8+ T cells by flow cytometry‐based assay. Cytokine levels in serum were measured by multiplex cytokine assay. Our data show that cells from TB patients have an increased percentage of peripheral blood CD8+αβ+ T (p = 0.02) and CD56+CD8+ T (p = 0.02) and a decreased frequency of NKG2D+CD8+ T (p = 0.02) compared with healthy donors. Unlike CD8+ T cells from healthy donors, CD8+ T cells from TB patients exhibit greater cytotoxicity, mediated by HLA class I molecules, on autologous monocytes in the presence of mycobacterial antigens (p = 0.005). Finally, TB patients have a proinflammatory profile characterized by serum high level of TNF‐α (p = 0.02) and IL‐8 (p = 0.0001), but, interestingly, IL‐4 (p = 0.002) was also increased compared with healthy donors. Our data show evidence regarding the highly cytotoxic status of CD8+ T cells in Mtb infection. These cytotoxic cells restricted to HLA‐A, B, and C could be used to optimize strategies for designing new TB vaccines or for identifying markers of disease progression.  相似文献   
88.
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease that has a mysterious relationship with malaria infection. The current study was designated to compare between the effect of the live and the gamma irradiated Plasmodium chabaudi infection on BWF1 lupus murine model. A total of 30 female BWF1 mice were randomly divided into three groups (10 mice/group) as follows: group (I) lupus group (lupus non infected); group (II) live malaria infected group (lupus + live malaria infection); and group (III) irradiated malaria-infected group (lupus + gamma irradiated malaria infection). Live P. chabaudi infection was accompanied with a decrease in survival rate and food consumption in comparison to the control group of mice while gamma irradiated P. chabaudi -infection was unable to do this effect. Additionally, live P. chabaudi infection was accompanied with an increased level of proteinuria and increased rate of immune complexes deposition in kidney. Moreover, infection with live, but not gamma-irradiated P. chabaudi was accompanied with an increase in nitric oxide (NO), hydrogen peroxide (H2O2), and malondialdehyde (MDA) levels in plasma of lupus mice. The levels of both total cholesterol and triglycerides in plasma of lupus mice after live P. chabaudi infection were obviously decreased in comparison to the control group. On the other hand, gamma-irradiated P. chabaudi infection resembled the control group. Our data revealed that infection of lupus mice with live but not gamma-irradiated P. chabaudi has several histological and biochemical effects.  相似文献   
89.
“Covariate adjustment” in the randomized trial context refers to an estimator of the average treatment effect that adjusts for chance imbalances between study arms in baseline variables (called “covariates”). The baseline variables could include, for example, age, sex, disease severity, and biomarkers. According to two surveys of clinical trial reports, there is confusion about the statistical properties of covariate adjustment. We focus on the analysis of covariance (ANCOVA) estimator, which involves fitting a linear model for the outcome given the treatment arm and baseline variables, and trials that use simple randomization with equal probability of assignment to treatment and control. We prove the following new (to the best of our knowledge) robustness property of ANCOVA to arbitrary model misspecification: Not only is the ANCOVA point estimate consistent (as proved by Yang and Tsiatis, 2001) but so is its standard error. This implies that confidence intervals and hypothesis tests conducted as if the linear model were correct are still asymptotically valid even when the linear model is arbitrarily misspecified, for example, when the baseline variables are nonlinearly related to the outcome or there is treatment effect heterogeneity. We also give a simple, robust formula for the variance reduction (equivalently, sample size reduction) from using ANCOVA. By reanalyzing completed randomized trials for mild cognitive impairment, schizophrenia, and depression, we demonstrate how ANCOVA can achieve variance reductions of 4 to 32%.  相似文献   
90.
摘要 目的:探讨与研究加减黄芪丹参饮联合优思悦治疗多囊卵巢综合征的效果及对外周血Th17/Treg免疫失衡的影响。方法:选择2018年7月到2022年1月在本院诊治的多囊卵巢综合征患者66例作为研究对象,根据1:1简单分配原则把患者分为中药组与对照组各33例。对照组给予优思悦治疗,中药组在对照组治疗的基础上给予加减黄芪丹参饮治疗,所有患者都治疗观察3个月经周期,测定与计算外周血Th17/Treg免疫失衡情况。结果:治疗后中药组的总有效率为100.0%,与对照组的81.8%相比明显增高(P<0.05)。两组治疗后的Th17/Treg值都明显低于治疗前(P<0.05),中药组与对照组相比也明显降低(P<0.05)。两组治疗后的子宫内膜厚度与最大卵泡直径都明显高于治疗前(P<0.05),治疗后中药组与对照组相比也明显提高(P<0.05)。两组治疗后的血清雌二醇(E2)含量明显高于治疗前(P<0.05),血清催乳素(PRL)含量明显低于治疗前(P<0.05),治疗后中药组与对照组都有明显差异差异(P<0.05)。结论:加减黄芪丹参饮联合优思悦治疗多囊卵巢综合征能有效调节外周血Th17/Treg免疫失衡,促进性激素分泌正常,提高患者的子宫内膜厚度与最大卵泡直径,提高患者的总体治疗效果。  相似文献   
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