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   1125篇
  免费   84篇
  国内免费   63篇
耳鼻咽喉   23篇
儿科学   13篇
妇产科学   11篇
基础医学   119篇
口腔科学   15篇
临床医学   79篇
内科学   253篇
皮肤病学   8篇
神经病学   68篇
特种医学   11篇
外科学   71篇
综合类   147篇
预防医学   46篇
眼科学   8篇
药学   259篇
中国医学   22篇
肿瘤学   119篇
  2023年   11篇
  2022年   31篇
  2021年   40篇
  2020年   31篇
  2019年   25篇
  2018年   29篇
  2017年   26篇
  2016年   32篇
  2015年   41篇
  2014年   58篇
  2013年   105篇
  2012年   68篇
  2011年   108篇
  2010年   73篇
  2009年   74篇
  2008年   84篇
  2007年   71篇
  2006年   57篇
  2005年   49篇
  2004年   40篇
  2003年   32篇
  2002年   26篇
  2001年   20篇
  2000年   14篇
  1999年   15篇
  1998年   9篇
  1997年   9篇
  1996年   10篇
  1995年   3篇
  1994年   11篇
  1993年   8篇
  1992年   5篇
  1991年   2篇
  1990年   4篇
  1989年   3篇
  1987年   2篇
  1986年   2篇
  1985年   5篇
  1984年   2篇
  1983年   2篇
  1982年   4篇
  1981年   3篇
  1979年   2篇
  1978年   2篇
  1976年   2篇
  1975年   2篇
  1974年   4篇
  1973年   5篇
  1972年   4篇
  1971年   4篇
排序方式: 共有1272条查询结果,搜索用时 920 毫秒
1.
2.
《Vaccine》2020,38(23):3934-3941
IntroductionSubjects with rheumatoid arthritis (RA) receiving tumor necrosis factor-inhibiting (TNFi) therapies are at risk for severe influenza, and may respond less well to influenza vaccine. We examined the safety and immunogenicity of high dose influenza vaccine (HD) compared to standard dose vaccine (SD) in participants with RA receiving stable TNFi.MethodsA randomized, double-blinded, Phase II study was conducted in adults with RA receiving TNFi, and healthy, gender and age-matched control subjects. Participants were immunized with HD (Sanofi Pasteur Fluzone High Dose [60 mcg × 3 strains]) or SD (Sanofi Pasteur Fluzone® [15 mcg × 3 strains]) intramuscularly (IM). A self-administered memory aid recorded temperature and systemic and local adverse events (AEs) for 8 days, and safety was evaluated and serum obtained to measure HAI activity on days 7, 21 and 180 days following vaccination.ResultsA greater proportion of RA subjects who received HD seroconverted at day 21 compared to SD, although this was not statistically significant. GMT antibody responses in RA subjects who received HD compared to SD were greater for all strains on day 21, and this was significant for H1N1. Seroconversion rates and GMT values were not different between RA subjects and control subjects. There were no safety concerns for HD or SD in RA subjects, and RA-related symptoms did not differ between SD and HD recipients by a RA-symptom questionnaire (RAPID 3).ConclusionsTNF-inhibitor therapy in people with RA did not appear to influence the immunogenicity of either SD or HD. Influenza seroconversion and GMT values were higher among RA subjects receiving HD compared to SD; however, differences were small and a larger study is needed to validate these findings. Given the apparent risk of increased influenza-related morbidity and mortality among immune compromised subjects, the higher GMT values generated by HD may be beneficial.  相似文献   
3.
BackgroundConsiderable progress has been made in therapeutic options for multiple myeloma (MM). Understanding the current landscape of MM treatment options and associated outcomes in the real world is important in providing key insights into clinical and knowledge gaps which could be targeted for further optimization.MethodsThe Canadian Myeloma Research Group Database (CMRG-DB) is a prospectively maintained disease-specific database with >7000 patients. The objective of this study was to describe the trends in the treatment landscape and outcomes including early mortality, time to next treatment, and overall survival (OS) in each line of treatment stratified by autologous stem cell transplant (ASCT) receipt among newly-diagnosed MM patients in Canada between 2007 and 2018.ResultsA total of 5154 patients were identified among which 3030 patients (58.8%) received an upfront ASCT and 2124 (41.2%) did not. At diagnosis, the median age was 64 years and 58.6% were males. Bortezomib and lenalidomide were most frequently used (>50%) in first and second-line treatment respectively among both the ASCT and non-ASCT cohort. The median OS was 122.0 months (95% Cl 115.0-135.0 months) and 54.3 months (95% CI 50.8-58.8 months) for the ASCT and non-ASCT cohort respectively with an incremental decrease in OS in each subsequent line of treatment.ConclusionWe present the largest study to date in the Canadian landscape showing the characteristics, therapy usage, and outcomes among MM patients. This information will be critical in benchmarking current outcomes and provide key insight into areas of unmet needs and gaps for improvement of MM patients nationally.  相似文献   
4.
精液中PAI-1含量与精液液化的关系   总被引:1,自引:1,他引:0  
目的测定精液中纤溶酶原激活物抑制剂-1(plasminogen activator inhibitor type-1,PAI-1)的含量,探讨精液的液化机制。方法分别检测门诊患者1h内不液化精液40例(A组)和1h内液化精液30例(B组)中PAI- 1的含量。结果A组PAI-1含量为(10.25±0.75)ng/ml,B组为(6.46±0.37)ng/ml,A组含量显著高于B组,P<0.01,差异有统计学意义。精液中PAI-1含量与精液液化时间的相关性r=0.362,P<0.01,呈正相关。结论精液中PAI-1含量升高,可导致精液液化时间延长,可作为检测精液粘稠度的一个相对指标。  相似文献   
5.
Stefan I McDonough 《Toxicon》2007,49(2):202-212
Some of the most potent and specific inhibitors of voltage-gated calcium channels are peptide toxins that inhibit channel function not by occlusion of the channel pore, but rather by interfering with the voltage dependence and kinetics of channel opening and closing. Many such gating modifier toxins conform to the inhibitor cystine knot structural family and have primary sequence or functional mechanism similar to toxins that target voltage-gated sodium or potassium channels. This review introduces known gating modifiers of calcium channels, discusses the selectivity, binding sites, and mechanism of the toxin-channel interaction, and reviews the usefulness of these toxins as research tools and as the basis for novel calcium channel pharmacology and therapeutics.  相似文献   
6.
Chymases (EC 3.4.21.39) are mast cell serine proteinases that are variably expressed in different species and, in most cases, display either chymotryptic or elastolytic substrate specificity. Given that chymase inhibitors have emerged as potential therapeutic agents for treating various inflammatory, allergic, and cardiovascular disorders, it is important to understand interspecies differences of the enzymes as well as the behavior of inhibitors with them. We have expressed chymases from humans, macaques, dogs, sheep (MCP2 and MCP3), guinea pigs, and hamsters (HAM1 and HAM2) in baculovirus-infected insect cells. The enzymes were purified and characterized with kinetic constants by using chromogenic substrates. We evaluated in vitro the potency of five nonpeptide inhibitors, originally targeted against human chymase. The inhibitors exhibited remarkable cross-species variation of sensitivity, with the greatest potency observed against human and macaque chymases, with Ki values ranging from ∼0.4 to 72 nM. Compounds were 10-300-fold less potent, and in some instances ineffective, against chymases from the other species. The X-ray structure of one of the potent phosphinate inhibitors, JNJ-18054478, complexed with human chymase was solved at 1.8 Å resolution to further understand the binding mode. Subtle variations in the residues in the active site that are already known to influence chymase substrate specificity can also strongly affect the compound potency. The results are discussed in the context of selecting a suitable animal model to study compounds ultimately targeted for human chymase.  相似文献   
7.
金立亭  冯贤松 《腹部外科》2008,21(4):246-248
目的探讨survivin、bFGF的表达与肝癌发生、发展及转移的关系并分析survivin与bFGF表达两者之间的联系。方法采用免疫组织化学方法(SABC法)检测54例肝细胞肝癌和10例正常肝组织中survivin和FbGF的表达。结果survivin和bFGF在正常肝组织中均不表达。肝癌组织中survivin和bFGF的阳性表达百分率分别为70.4%和74.1%,与正常肝组织相比具有非常显著性差异(P〈0.01)。suvivin与bFGF二者共同表达率为61.1%,其表达阳性程度呈显著正相关(P〈0.01)。结论联合检测Survivin和bFGF有助于肝癌病理分级、恶性程度判定和预后判断。survivin和bFGF可作为肝癌早期诊断、治疗和判断预后的新靶点。  相似文献   
8.
Human immunodeficiency virus type 1 (HIV-1) fusion with its target cells is initiated by sequential interactions between its envelope glycoprotein, CD4, and a co-receptor, usually CCR5 or CXCR4. Small molecules that bind to CCR5 and prevent its use by R5 HIV-1 strains are now being developed clinically as antiviral drugs. To test whether a block to CCR5 promotes the replication of viruses that enter cells via CXCR4 and are associated with accelerated disease progression, we administered a small molecule CCR5 inhibitor, CMPD 167, to three macaques dual-infected with both R5 (SIVmac251) and X4 (SHIV-89.6P) viruses. CMPD 167 caused a rapid and substantial (on average, 50-fold) suppression of R5 virus replication in each animal. In two of the animals, but not in the third, a rapid, transient, 8- to 15-fold increase in the amount of plasma X4 virus occurred. In neither animal was the increase in X4 viral load sustained throughout therapy, however. These observations may have relevance for the development of CCR5 inhibitors for treatment of HIV-1 infection of humans.  相似文献   
9.
10.
The possible characteristics of spinal interaction between sildenafil (phosphodiesterase 5 inhibitor) and morphine on formalin-induced nociception in rats was examined. Then the role of the opioid receptor in the effect of sildenafil was further investigated. Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. For induction of pain, 50 µL of 5% formalin solution was applied to the hind-paw. Isobolographic analysis was used for the evaluation of drug interaction between sildenafil and morphine. Furthermore, naloxone was intrathecally given to verify the involvement of the opioid receptor in the antinociception of sildenafil. Both sildenafil and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. The isobolographic analysis revealed an additive interaction after intrathecal delivery of the sildenafil-morphine mixture in both phases. Intrathecal naloxone reversed the antinociception of sildenafil in both phases. These results suggest that sildenafil, morphine, and the mixture of the two drugs are effective against acute pain and facilitated pain state at the spinal level. Thus, the spinal combination of sildenafil with morphine may be useful in the management of the same state. Furthermore, the opioid receptor is contributable to the antinocieptive mechanism of sildenafil at the spinal level.  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