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   1147篇
  免费   76篇
  国内免费   9篇
耳鼻咽喉   11篇
儿科学   76篇
妇产科学   11篇
基础医学   96篇
口腔科学   34篇
临床医学   105篇
内科学   283篇
皮肤病学   21篇
神经病学   27篇
特种医学   250篇
外科学   78篇
综合类   62篇
预防医学   69篇
眼科学   20篇
药学   43篇
中国医学   9篇
肿瘤学   37篇
  2023年   2篇
  2021年   4篇
  2020年   7篇
  2019年   10篇
  2018年   13篇
  2017年   10篇
  2016年   8篇
  2015年   20篇
  2014年   39篇
  2013年   63篇
  2012年   30篇
  2011年   31篇
  2010年   41篇
  2009年   61篇
  2008年   32篇
  2007年   53篇
  2006年   30篇
  2005年   28篇
  2004年   26篇
  2003年   17篇
  2002年   23篇
  2001年   14篇
  2000年   16篇
  1999年   16篇
  1998年   78篇
  1997年   55篇
  1996年   67篇
  1995年   47篇
  1994年   49篇
  1993年   46篇
  1992年   10篇
  1991年   5篇
  1990年   11篇
  1989年   39篇
  1988年   28篇
  1987年   25篇
  1986年   19篇
  1985年   13篇
  1984年   18篇
  1983年   18篇
  1982年   15篇
  1981年   21篇
  1980年   13篇
  1979年   8篇
  1978年   9篇
  1977年   16篇
  1976年   8篇
  1975年   11篇
  1973年   2篇
  1833年   1篇
排序方式: 共有1232条查询结果,搜索用时 15 毫秒
51.
High-dose intravenous gammaglobulin (polyvalent immunoglobulin G) has been shown to be of benefit in some patients with immune thrombocytopenic purpura (ITP), possibly by producing reticuloendothelial system blockade. We studied this approach in patients refractory to random donor platelet transfusion using an IV IgG preparation manufactured by the Swiss Red Cross. Eleven adult patients with acute leukemia received either 0.4 g IgG/kg/d intravenously X five days (four patients) or 0.6 g/kg/d X five days (seven patients). All patients had high levels of lymphocytotoxic antibody and poor responses to random donor platelets. Except for mild headaches in two patients, there were no side effects related to the IgG infusions. All patients had significant elevations of serum IgG on the day after completion of treatment. Either random donor or partially HLA-matched platelet transfusions were administered the day after and, in some cases, during the IgG therapy. No patient had an improvement in one hour posttransfusion platelet count increments. Two additional patients received pooled platelet concentrates incubated for 30 minutes at 37 degrees C with IgG at a final concentration of 3 g% prior to transfusions. These results indicate that high-dose IgG, an extremely expensive treatment, cannot be recommended for alloimmunized adults with leukemia.  相似文献   
52.
SUMMARY Clinically significant symptoms due to gastrointestinal metastases from primary lung cancers is rare. A case of life-threatening lower gastrointestinal haemorrhage secondary to metastatic squamous cell carcinoma of the lung is reported. Previous reports of such metastases are reviewed, with reference to management and prognosis. After resection of colonic metastases from squamous cell lung cancer, survival is similar to that for primary disease. It is suggested that patients with known or suspected squamous cell lung cancer presenting with lower gastrointestinal symptoms be managed as aggressively as those with no previous history of disease.  相似文献   
53.
中西医结合治疗老年高脂血症   总被引:2,自引:1,他引:2  
目的:探讨中西医结合治疗高脂血症的临床疗效。方法:符合高脂血症标准的老年患者120例,随机分为A、B2组各60例,A组采用益肾化淤、利湿化浊为主的中药及西药辛伐他汀片治疗;B组则单纯用辛伐他汀片治疗。治疗前及治疗4周后2组均行全套血脂水平测定。结果:与B组比较,A组血清总胆固醇(TC)及甘油三酯(TG)均明显下降,HDL明显上升(均P〈0.05);A组临床控制率明显高于B组(P〈0.05);治疗后A组患者未见肝功能损害,B组转氨酶及转肽酶轻度异常,2例。停药3个月后,A组复发率低于B组(2.2%、8.8%,P〈0.05)。结论:中西医结合治疗老年高脂血症的临床效果明显优于单一的一种治疗方法,值得临床进一步推广应用。  相似文献   
54.
55.
56.
Primary Autosomal Recessive Microcephaly (MCPH) is characterized by congenital microcephaly usually without additional clinical findings. The most common gene implicated in MCPH is ASPM and a large percentage of mutations described have been homozygous and in consanguineous families primarily of East Asian and Middle Eastern origin. ASPM sequencing was performed on 400 patients between the years 2009 and 2012. Seventy of the patient samples were also analyzed for copy number changes in the ASPM gene. Forty protein truncating mutations, including 29 novel mutations, were identified in 39 patients with MCPH. Approximately one third of patients were compound heterozygotes, indicative of non‐consanguinity in these patients. In addition, 46 non‐synonymous variants were identified and interpreted as variants of uncertain significance. No deletion/duplication in ASPM was identified in the patients analyzed. A wide ethnic distribution was observed, including the first reported patients with ASPM‐related MCPH of Hispanic descent. Clinical information was collected for 26 of the ASPM‐positive patients and 41 of the ASPM‐negative patients. As more individuals are identified with MCPH, we anticipate that we will continue to identify ASPM mutation‐positive patients from all ethnic origins supporting the occurrence of this genetic condition beyond that of consanguineous families of certain ethnic populations.  相似文献   
57.
目的 白细胞介素 1 3(IL 1 3)是新近发现的一种抗炎性细胞因子 ,其在肾小球肾炎中的作用尚不清楚 ,该研究探讨脂多糖 (LPS)对体外培养的人肾小球系膜细胞 (HMC)表达IL 1 3作用以及IL 1 3对HMC促炎性细胞因子、趋化因子和促纤维化因子基因表达的影响。方法 体外培养HMC ,加入不同浓度的LPS和 (或 )IL 1 3后 ,用逆转录 -聚合酶链反应和ELISA检测HMCIL 1 3mRNA表达和细胞培养上清液中IL 1 3蛋白含量 ;应用核酸酶保护法检测HMC肿瘤坏死因子 α(TNF α)、白介素 - 1α(IL 1α)、白介素 - 1 β(IL 1 β)、单核细胞趋化蛋白 1(MCP 1 )、白介素 8(IL 8)、转化生长因子 - β1 (TGF β1 )mRNA的表达。 结果 未予LPS刺激的HMC不表达IL 1 3mRNA和蛋白 ;LPS呈剂量依赖性和时间依赖性诱导HMC表达IL 1 3mRNA和分泌IL 1 3蛋白。HMC受LPS刺激后 1 2h即可表达IL 1 3mRNA ,4 8h达高峰 ,72h仍维持在较高的水平。HMC受LPS刺激后 2 4h ,其培养上清液中检测到IL 1 3蛋白 ,4 8h和 72h进一步增加。外源性IL 1 3呈剂量依赖性地抑制LPS诱导的系膜细胞TNF α ,IL 1α ,IL 1 β ,MCP 1 ,IL 8,TGF β1mRNA的表达。应用抗IL 1 3抗体中和内源性IL 1 3后 ,上述炎症因子表达增强。结论 IL 1 3是HMC自分泌因子。IL 1 3可抑制LPS诱导  相似文献   
58.
目的 探讨病毒性心肌炎患儿心率变异性(HRV)与心率减速力(DC)各项指标变化的临床意义.方法 对56例病毒性心肌炎患儿与58例正常对照儿童进行24h动态心电图检查,应用美国DMS公司的动态心电分析系统软件,对HRV及DC各项参数进行分析对比;并分析DC与其他各项指标之间的相关性.结果 与正常对照儿童比较,病毒性心肌炎患儿时域分析的各项参数包括正常窦性RR间期的标准差(SDNN)、每5 min时段内平均正常窦性RR间期的标准差(SDANN)、全程RR间期差的均方根(RMSSD)及频域分析的低频功率(LF)的差异均无统计学意义(P>0.05),而高频功率(HF)显著减低,差异有统计学意义(P<0.05),且DC显著减低,差异有统计学意义(P<0.01).相关性分析中,DC与SDNN、LF、HF均成正相关,其中与HF的相关性最强(r=0.51,P<0.01).结论病毒性心肌炎患儿存在迷走神经功能受损,心率变异性中的HF与DC反映迷走神经功能的指标均显著降低,且两者具有很大相关性.  相似文献   
59.
Supravalvular aortic stenosis (SVAS) is an inherited obstructive vascular disease that affects the aorta, carotid, coronary and pulmonary arteries. Previous molecular genetic data have led to the hypothesis that SVAS results from mutations in the elastin gene, ELN. In these studies, the disease phenotype was linked to gross DNA rearrangements (35 and 85 kb deletions and a translocation) in three SVAS families. However, gross rearrangements of ELN have not been identified in most cases of autosomal dominant SVAS. To define the spectrum of ELN mutations responsible for this disorder, we refined the genomic structure of human ELN and used this information in mutational analyses. ELN point mutations co-segregate with the disease in four familial cases and are associated with SVAS in three sporadic cases. Two of the mutations are nonsense, one is a single base pair deletion and four are splice site mutations. In one sporadic case, the mutation arose de novo. These data demonstrate that point mutations of ELN cause autosomal dominant SVAS.   相似文献   
60.
The aim of this study was to compare 70 couples who had conceived by in- vitro fertilization (IVF) with 63 matched controls for the prevalence of anxiety and quality of attachment to the baby during pregnancy. Results for mothers showed no group differences using a global measure of anxiety, the Spielberger State-Trait Anxiety Inventory. However, pregnancy-specific measures revealed significantly higher levels of anxiety in IVF mothers about the survival and normality of their unborn babies, about damage to their babies during childbirth and about separating from their babies after birth. When IVF mothers were differentiated according to the number of treatment cycles, more differences in anxiety level were revealed, with most increases occurring in mothers who had experienced two or more treatment cycles. IVF fathers did not differ from controls on the global anxiety measure. No data on pregnancy-specific anxiety were available for fathers. Neither IVF mothers nor IVF fathers differed from controls on measures of attachment to the baby during pregnancy. Results are discussed in the context of the need for researchers to employ differentiated and issue-specific measures to identify concerns that may be unique to IVF couples. Clinical implications regarding the need for psychological support during pregnancy are also discussed.   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