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   19310篇
  免费   1677篇
  国内免费   1390篇
耳鼻咽喉   184篇
儿科学   150篇
妇产科学   246篇
基础医学   2281篇
口腔科学   213篇
临床医学   2296篇
内科学   3392篇
皮肤病学   191篇
神经病学   929篇
特种医学   724篇
外国民族医学   11篇
外科学   2085篇
综合类   3214篇
一般理论   2篇
预防医学   1096篇
眼科学   562篇
药学   2031篇
  15篇
中国医学   966篇
肿瘤学   1789篇
  2024年   65篇
  2023年   320篇
  2022年   748篇
  2021年   963篇
  2020年   678篇
  2019年   655篇
  2018年   731篇
  2017年   574篇
  2016年   609篇
  2015年   856篇
  2014年   1053篇
  2013年   869篇
  2012年   1373篇
  2011年   1512篇
  2010年   858篇
  2009年   721篇
  2008年   1050篇
  2007年   1005篇
  2006年   980篇
  2005年   960篇
  2004年   648篇
  2003年   599篇
  2002年   524篇
  2001年   471篇
  2000年   525篇
  1999年   467篇
  1998年   346篇
  1997年   307篇
  1996年   273篇
  1995年   263篇
  1994年   178篇
  1993年   129篇
  1992年   168篇
  1991年   161篇
  1990年   127篇
  1989年   124篇
  1988年   112篇
  1987年   99篇
  1986年   95篇
  1985年   61篇
  1984年   29篇
  1983年   23篇
  1982年   11篇
  1981年   17篇
  1980年   10篇
  1979年   7篇
  1978年   7篇
  1977年   3篇
  1976年   4篇
  1974年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
青光眼滤过术后浅前房的预防和处理   总被引:3,自引:11,他引:3  
目的:探讨青光眼滤过性手术浅前房的发生、发展和预防处理。方法:回顾性研究了我院过去102例(112眼),其中急性闭角型青光眼64例(67眼),慢性闭角型青光眼7例(11眼),开角型青光眼26例(29眼),继发性青光眼5例(5眼)的治疗经过。结果:112眼中术后24h有77眼前房形成,占68.8%,发生I型浅前房23眼,II型9眼,III型3眼,共占32.2%,其中5眼分别于术后2~4d变浅。荧光素试验发现结膜切口渗漏者3眼,有较明显睫状体脉络膜脱离5眼,小眼球并发晶状体膨胀2眼,恶性青光眼1眼,均经相应处理后前房恢复。结论:青光眼滤过性手术浅前房的发生率是较高的,但只要加强手术前后的治疗处理,术中仔细操作,多数浅前房是可以预防的,即使发生了浅前房只要处理及时和恰当,预后也是良好的。  相似文献   
72.
The periosteum, a highly vascularized thin tissue, has excellent osteogenic and bone regenerative abilities. The generation of periosteum-mimicking tissue has become a novel strategy for bone defect repair and regeneration, especially in critical-sized bone defects caused by trauma and bone tumor resection. Here, we utilized a bone morphogenetic protein-2(BMP-2)-loaded scaffold to create periosteum-like tissue(PT) in vivo, mimicking the mesenchymal condensation during native long bone developmen...  相似文献   
73.
74.
Two cases of cervical pregnancy with heavy bleeding successfully treated by uterine artery embolization (UAE) followed by immediate curettage are described in this report. Case 1 demonstrated intermittent bleeding after serious bleeding was successfully controlled by UAE. Serum beta human chorionic gonadotropin (beta-hCG) level rose remarkably after a short time decline. Transvaginal sonography consistently revealed a heterogeneous mass in the cervix. Repeated UAE followed by immediate curettage was performed and complete resolution was achieved. Case 2 was also successfully managed by UAE followed by immediate curettage after failure of medical treatment. This report suggests that UAE followed by immediate curettage is a safe and efficient procedure for controlling heavy bleeding and avoiding recurrent bleeding when fertility capacity is desired in cases of cervical pregnancy with fetal cardiac activity and high beta-hCG concentration.  相似文献   
75.
人胃癌SGC7901细胞膜钾离子通道的特性   总被引:8,自引:0,他引:8  
目的 研究人胃癌细胞系 SGC790 1细胞膜钾离子通道特性 .方法 以人胃癌细胞系 SGC790 1为研究对象 ,采用穿孔膜片钳全细胞记录法 .结果 人的胃癌 SGC790 1细胞系的静息膜电位为 (- 32 .2± 2 .2 ) m V,在钳制电压 - 40 m V,阶跃电压在 - 80~ +80 m V,记录到一种跨膜电流 ,该跨膜电流具有电压依赖、外向整流特性 ,该电流在延迟 2 5 ms后最大激活 ,80 0 m s内不失活 ,翻转电位在 - 6 0~ - 40 m V,能被已知的钾通道的阻断剂 4- AP或 TEA阻断 .结论 在人胃癌SGC790 1细胞系细胞膜上存在延迟整流钾离子通道 .  相似文献   
76.
目的: 探讨心脏死亡供体(donation after cardiac death,DCD)原位肝移植术后胆道并发症的发生因素、诊断要点和治疗方法。方法: 对2015年1月—2016年8月于南京医科大学第一附属医院肝移植中心实施的87例DCD供肝肝移植患者临床资料进行回顾性分析。87例中29例行经典原位肝移植,58例行改良背驮式肝移植,胆管重建方式均为胆总管端端吻合,无1例放置T管。结果: 87例肝移植患者中9例通过胆道造影确诊为肝移植术后胆道并发症, 8例治愈, 1例好转, 无死亡。胆道并发症发生率10.1%(9/87)。结论: DCD供体原位肝移植术后胆道并发症的发生与供肝缺血时间、DCD供肝质量、胆管吻合技术及供肝修剪技术等因素有关,术后胆道造影有助于及时诊断胆道并发症。介入技术是胆道并发症的主要治疗手段。  相似文献   
77.
PurposeTo assess the feasibility of applying ultra-widefield fundus (UWF) images for macular staphyloma area (MSA) measurement and investigate the associated factors with MSA.MethodsThis is a retrospective study. MSA was measured by UWF imaging. Central foveal thickness, subfoveal choroidal thickness, subfoveal scleral thickness were measured on spectral domain optical coherence tomography. Intraclass correlation coefficients of MSA measurement would be evaluated. Multiple linear regression analysis was used to analyze the associated factors with MSA.ResultsIn total, 135 eyes of 92 patients were enrolled. The mean age was 64.73 ± 10.84 years. Mean MSA on UWF image was 279.67 ± 71.70 mm2. Intraclass correlation coefficients of MSA measurement was 0.965 (95% confidence interval [CI], 0.946 to 0.977; p < 0.001). In the multiple linear regression analysis, after adjusting for subfoveal choroidal thickness, best-corrected visual acuity, central foveal thickness, and subfoveal scleral thickness, the factors independently related to MSA were axial length (β = 8.352; 95% CI, 3.306 to 13.398; p = 0.001), sex (β = −26.673; 95% CI, −51.759 to −1.586; p = 0.037), age (β = 1.184; 95% CI, 0.020 to 2.348; p = 0.046).ConclusionsIt is feasible to measure MSA on UWF image. Female, longer axial length, and older age may indicate larger MSA.  相似文献   
78.
We spectroscopically investigated coordination state of Fe3+ in methanol (MeOH) and ethanol (EtOH) solutions against Cl concentration ([Cl]). In both the system, we observed characteristic absorption bands due to the FeCl4 complex at high-[Cl] region. In the MeOH system, the proportion (r) of [FeCl4] exhibits a stationary value of 0.2–0.3 in the intermediate region of 10 mM < [Cl] < 50 mM, which is interpretted in terms of [FeClnL6−n]3−n (n = 1 and 2). In the EtOH system, r steeply increases from 0.1 at [Cl] = 1.5 mM to 0.7 at [Cl] = 3.5 mM, indicating direct transformation from [FeL6]3+ to [FeCl4]. We further found that the coordination change significantly decreases the redox potential of Fe2+/Fe3+.

Fe3+ coordination in alcohol solution can be controlled by the Cl concentration ([Cl]). The coordination state changes from FeL6 (L: solvent molecule) to FeCl4 type via FeClnL6−n with increases in [Cl].  相似文献   
79.
ContextValerian extract capsule (VEC) is an effective Chinese patent medicine used for gastrointestinal (GI) diseases.ObjectiveTo investigate the detailed pharmacological activity for VEC clinical effects in GI diseases.Materials and methodsSprague-Dawley rats were divided into six groups: control, model, and drug-treated (VEC-L, VEC-M, VEC-H, and teprenone). Rats were orally administered VEC (124, 248, 496 mg/kg) and teprenone (21.43 mg/kg) for 3 consecutive days. After 1 h, the five groups (except the control group) were orally given ethanol (10 mL/kg) for 1 h or indomethacin (80 mg/kg) for 7 h. The spasmolytic activity of VEC (0.01–1 mg/mL) on ACh/BaCl2-induced New Zealand rabbit smooth muscle contraction was performed. The C57BL/6 mice carbon propelling test evaluated the effects of VEC (248–992 mg/kg) on intestinal motility in normal and neostigmine/adrenaline-induced mice.ResultsCompared with the model group, VEC treatment reduced the gastric lesion index and mucosal damage. Further experiments showed that the pathological ameliorative effect of VEC was accompanied by augmentation of the enzymatic antioxidant system and cytoprotective marker (COX-1, p < 0.01; PGI2 p < 0.05;), along with the alleviation of the levels of MPO (ethanol: 15.56 ± 0.82 vs. 12.15 ± 2.60, p < 0.01; indomethacin: 9.65 ± 3.06 vs. 6.36 ± 2.43, p < 0.05), MDA (ethanol: 1.66 ± 0.44 vs. 0.81 ± 0.58, p < 0.01; indomethacin: 1.71 ± 0.87 vs. 1.09 ± 0.43, p < 0.05), and inflammatory mediators. VEC decreased the high tone induced by ACh/BaCl2 and promoted intestinal transit in normal and neostigmine/adrenaline-induced mice.Discussion and conclusionsVEC showed a potential gastroprotective effect, suggesting that VEC is a promising phytomedicine for the treatment of GI diseases.  相似文献   
80.
ObjectiveThis study was performed to examine the relationship between the C-reactive protein/albumin ratio (CAR) and the prognosis of patients with lung adenocarcinoma and thus provide a reference for evaluating the prognosis of lung adenocarcinoma.MethodsThe clinical data of 130 patients with lung adenocarcinoma were retrospectively collected and analyzed. The patients’ overall survival (OS) time was calculated, and the factors affecting OS were statistically analyzed.ResultsThe CAR was correlated with sex, clinical stage, brain metastasis, S100 calcium-binding protein B (S100B), interleukin 17, myelin basic protein, squamous cell carcinoma antigen (SCC-Ag), and the lymphocyte count. The median OS was significantly shorter in the high- than low-CAR group (18 vs. 64 months, respectively). The CAR, clinical stage, brain metastasis, S100B, interleukin 17, SCC-Ag, C-reactive protein, albumin, and neutrophil count affected the OS of patients with lung adenocarcinoma. The CAR and clinical stage were independent risk factors for a poor prognosis in patients with lung adenocarcinoma.ConclusionsThe CAR and clinical stage are independent risk factors for OS in patients with lung adenocarcinoma.  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