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   3612篇
  免费   291篇
  国内免费   140篇
耳鼻咽喉   11篇
儿科学   80篇
妇产科学   138篇
基础医学   816篇
口腔科学   59篇
临床医学   318篇
内科学   610篇
皮肤病学   54篇
神经病学   186篇
特种医学   36篇
外科学   160篇
综合类   575篇
预防医学   162篇
眼科学   57篇
药学   457篇
  1篇
中国医学   143篇
肿瘤学   180篇
  2024年   9篇
  2023年   46篇
  2022年   71篇
  2021年   105篇
  2020年   104篇
  2019年   90篇
  2018年   106篇
  2017年   108篇
  2016年   119篇
  2015年   109篇
  2014年   176篇
  2013年   308篇
  2012年   185篇
  2011年   231篇
  2010年   151篇
  2009年   149篇
  2008年   153篇
  2007年   222篇
  2006年   176篇
  2005年   157篇
  2004年   149篇
  2003年   125篇
  2002年   123篇
  2001年   117篇
  2000年   103篇
  1999年   85篇
  1998年   87篇
  1997年   97篇
  1996年   69篇
  1995年   72篇
  1994年   58篇
  1993年   26篇
  1992年   20篇
  1991年   15篇
  1990年   21篇
  1989年   10篇
  1988年   8篇
  1987年   3篇
  1986年   6篇
  1985年   11篇
  1984年   12篇
  1983年   5篇
  1982年   10篇
  1981年   9篇
  1980年   10篇
  1979年   4篇
  1978年   4篇
  1977年   3篇
  1976年   3篇
  1975年   2篇
排序方式: 共有4043条查询结果,搜索用时 171 毫秒
1.
2.
目的 :探讨血清可溶性白细胞介素 2受体 (sIL 2R)在慢性乙型病毒性肝炎 (慢乙肝 )中的发病机制及sIL 2R与肝纤维化指标、肝功能的相关关系。方法 :对 312例肝活检病人按组织病理学炎症和纤维化程度进行分级分期 ,同时检测了病人血清sIL 2R、肝功能及肝纤维化相关指标。结果 :血清sIL 2R均值较对照组明显增高 (P <0 .0 1) ,增幅随着肝脏病理炎症和纤维化程度的加重而逐渐加大 ,各组间比较差异有显著性 (P <0 .0 5或P <0 .0 1)。sIL 2R与血清白蛋白 (A)呈显著负相关 ,与血清脯氨酸肽酶 (PLD)、Ⅳ型胶原 (CⅣ )、层粘连蛋白 (LN)、透明质酸 (HA)、Ⅲ型前胶原氨基端肽 (PⅢNP)、肝功指标中的TB、DB、G、ALT、AST、AKP、γ GT呈显著正相关 (P <0 .0 5或P <0 .0 1)。结论 :慢乙肝病人血清sIL 2R水平与A呈显著负相关 ,与PLD、CⅣ、LN、HA、PⅢNP呈显著正相关 ;sIL 2R的血清水平能反映肝脏组织学病变的程度 ,可作为判断肝组织炎症和纤维化程度的参考指标。  相似文献   
3.
目的探讨可溶性细胞间黏附分子(sICAM-1)在急性肝内胆汁淤积兔模型中的表达及其意义。方法39只健康的新生大耳白兔随机分成4组:3个实验组(n=9)和1个空白对照组(n=12)。每个实验组分别为3个时间点处理组(24、48、72 h)。实验组采用1次灌服α-荼异硫氰酸盐(ANIT)200 mg/kg方法造成急性肝内胆汁淤积。按时分批取标本,检测其血清和胆汁中sICAM-1水平。结果实验组血清、胆汁中sICAM-1各时间点水平明显高于正常对照组(P均<0.05),其中48 h>72 h>24 h。结论sICAM-1在胆汁淤积中表达升高,与肝脏损伤程度和病程相关。  相似文献   
4.
目的观察卡维地洛对不稳定型心绞痛(UAP)患者高敏C反应蛋白(hs-CRP)、白介素-6(IL-6)及细胞间可溶性黏附分子1(sICAM-1)水平的影响。方法UAP患者62例采用完全随机化方法分成对照组(n=30)和治疗组(n=32),在常规抗血小板、扩血管治疗基础上,对照组予美托洛尔(12.5mg,2次/d×3d)口服,治疗组服卡维地洛(6.25mg,2次/d×3d),在治疗前后分别测定hs-CRP、IL-6、sICAM-1值。结果对照组和治疗组在治疗前hs-CRP、IL-6、sICAM-1均无显著性差异;用药后两组3指标均较用药前显著降低(P<0.05);治疗组在用药后IL-6、sI-CAM-1显著低于对照组(P<0.05)。同时,用药后两组患者的心率、血压、心肌耗氧量均较用药前显著降低(P<0.05),治疗组的心肌耗氧量显著低于对照组(P<0.05)。结论卡维地洛可显著降低UAP患者的炎症因子IL-6、sICMA-1水平。  相似文献   
5.
The endotoxin receptor soluble CD14 (sCD14) has been implicated in the 'hygiene hypothesis' suggesting reduced allergic sensitization with bacterial stimulation. However, the relationship between early life sCD14 and allergic diseases is conflicting. We aimed to investigate whether possible risk factors for allergic diseases were associated with sCD14 levels at 2 yr of age. In the nested case-control study of the birth cohort studies 'Environment and Childhood Asthma study in Oslo' 411 children selected with recurrent bronchial obstruction (rBO) (n=241) and no bronchial obstruction (n=170) by 2 yr were investigated with skin prick test and structured parental interview at age 2 yr. Exposure to tobacco smoke, pets and infections was recorded semi-annually by questionnaires (0-2 yr). The sCD14 was analysed from frozen, stored serum by ELISA technique. Regression analyses were performed in all subjects with complete data (n=406, 180 girls), and in girls and in boys separately. Mean sCD14 (ng/ml) was significantly higher among girls 2035 (1973-2096) vs. 1947 (1890-2004) (boys). The sCD14 was significantly reduced among girls exposed to antenatal maternal smoking and with parental asthma, after adjusting for age, parental rhino-conjunctivitis, pet keeping and childhood infections. Recurrent otitis media (OM) increased and common colds significantly decreased sCD14 levels in girls. Boys with atopic dermatitis and rBO had reduced sCD14. Pet exposure was not significantly associated with sCD14. We report novel gender-related effects of sCD14 in early life and suggest that gender, tobacco smoke exposure, age and middle ear disease in particular should be accounted for when assessing the role of sCD14 in childhood allergic diseases.  相似文献   
6.
PROBLEM: There is substantial data that support the efficacy of paternal leukocyte immunization (PLI) for the treatment of alloimmune mediated miscarriage; however, there is confusion regarding the laboratory test that should be performed to determine levels of maternal anti-paternal leukocyte antibodies (MAPLA). METHOD: Popular methodologies employed include: 1) microcytotoxicity (MCX), 2) mixed lymphocyte culture (MLC), and 3) cell flow cytometry crossmatch (FCXM). Cell flow cytometry crossmatch correlates well with the more difficult MLC assay although the former proves the more sensitive study. This work compares the MCX assays with FCXM. The study group consisted of ten women who had a history of three or more spontaneous abortions (SABs). All ten had very low levels (<10%) of MAPLA as measured by FCXM. Following PLI all subjects demonstrated elevated levels (>50%) of MAPLA by FCXM. At 12 weeks gestation, sera were simultaneously measured for MAPLA by MCX and FCXM. RESULTS: Although all ten patients had very high levels of MAPLA by FCXM during pregnancy, five of ten had antibodies to HLA Class I and two of ten had antibodies to HLA Class II paternal antigens by MCX. Furthermore, all patients who were positive by MCX to paternal Class I antigens were also positive to Class I antigens not seen in either parent. Both patients who were positive by MCX to paternal Class II antigens were also positive to maternal Class II antigens. Notable is that all ten women eventually delivered healthy infants. CONCLUSION: Based on this preliminary study, the MCX assay is neither sensitive or reliable enough to determine the need and/or to monitor the effectiveness of PLI. Flow cytometry should be the modality of choice when determining the need for alloimmunotherapy and to monitor the effectiveness of treatment.  相似文献   
7.
Radiotherapy(RT)is an important ap-proach for treatment of esophageal carcinoma(EC),especially for patients who have missedthe chance of surgical section.The efficacy ofRTis not satisfactory for its1-year,3-year and5-year survival rates being merely50%,20%,and10%respectively(1).Researches in recent years showed thatbetter efficacy can be obtained by combiningRTwith Chinese herbal medicines for EC thatincapable to be resected.Kang ai Injection(康艾注射液,KAI)is a Chinese herbal prep-arati…  相似文献   
8.
目的探索可溶性HLAG1分子结构对功能的影响,为其临床应用打下基础。方法通过分子克隆技术,去掉HLAG1重链分子α1功能区氨基端24肽,然后与轻链蛋白在体外与九肽共折叠复性形成复合物,并检测复合物对NK细胞杀伤活性的影响。结果成功构建突变的HLAG1重链分子的原核表达载体,表达的重链蛋白与轻链蛋白形成复合物,经Westernblot鉴定可与HLAⅠ类分子的单抗W6/32结合,并且可明显抑制NK细胞对K562细胞的细胞毒作用。结论α1功能区氨基端缺失24肽的HLAG1分子,可抑制NK细胞的细胞毒作用。  相似文献   
9.
10.
使用ELISA双抗夹心法对临床43例造血系统恶性肿瘤患者及20例健康体检人员的血清sIL-2R进行检测,并对ALL和ANLL复发与未复发患者的血清sIL-2R水平进行了比较分析。实验结果表明,血清sIL-2R水平的升高是造血系统恶性肿瘤的重要标志之一;测定血清sIL-2R水平对造血系统恶性肿瘤的辅助诊断、疗效观察及预后估计具有重要意义。  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