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   49972篇
  免费   4553篇
  国内免费   1937篇
耳鼻咽喉   98篇
儿科学   2310篇
妇产科学   182篇
基础医学   2630篇
口腔科学   176篇
临床医学   8242篇
内科学   11701篇
皮肤病学   283篇
神经病学   1471篇
特种医学   1314篇
外国民族医学   5篇
外科学   4621篇
综合类   9992篇
现状与发展   13篇
一般理论   1篇
预防医学   2445篇
眼科学   522篇
药学   5062篇
  68篇
中国医学   2848篇
肿瘤学   2478篇
  2024年   132篇
  2023年   1011篇
  2022年   1305篇
  2021年   2888篇
  2020年   2432篇
  2019年   1803篇
  2018年   1652篇
  2017年   1764篇
  2016年   2002篇
  2015年   1902篇
  2014年   3203篇
  2013年   3614篇
  2012年   2944篇
  2011年   3179篇
  2010年   2508篇
  2009年   2278篇
  2008年   2348篇
  2007年   2475篇
  2006年   2235篇
  2005年   2140篇
  2004年   1942篇
  2003年   1874篇
  2002年   1146篇
  2001年   1014篇
  2000年   917篇
  1999年   685篇
  1998年   633篇
  1997年   589篇
  1996年   542篇
  1995年   460篇
  1994年   381篇
  1993年   276篇
  1992年   271篇
  1991年   211篇
  1990年   155篇
  1989年   187篇
  1988年   172篇
  1987年   131篇
  1986年   127篇
  1985年   214篇
  1984年   134篇
  1983年   94篇
  1982年   108篇
  1981年   96篇
  1980年   69篇
  1979年   65篇
  1978年   49篇
  1977年   36篇
  1976年   29篇
  1975年   17篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的探讨重症急性胰腺炎的合理治疗方案。方法以1985年1月~2005年8月间收治的102例重症急性胰腺炎作研究对象,比较手术组与非手术组的主要并发症和死亡率。A组:1985年1月~1993年12月以手术治疗为主41例;B组:1994年1月~2005年8月以早期非手术治疗为主61例。结果手术组死亡率和并发症发生率明显高于非手术组,两组病死率及并发症发生率比较差异有显著性(P〈0.05)。结论重症急性胰腺炎采用早期非手术治疗能有效降低病死率和并发症发生率。大多数重症急性胰腺炎可经非手术治愈。  相似文献   
62.
BACKGROUND: Stringent transcranial Doppler (TCD) criteria for diagnosing occlusion are needed for more reliable TCD performance at bedside in the acute stroke setting. SUBJECTS AND METHODS: At three academic stroke centers, we performed TCD examination for patients with symptoms of cerebral ischemia who underwent digital subtraction angiography (DSA). We used a standard insonation protocol with power M-mode Doppler (PMD) TCD (TCD 100 M, Spencer Technologies Inc., Seattle, WA). We collected mean flow velocity (MFV), pulsatility indices (PI), and power M-mode resistance signature (absent, high, or low) in symptomatic middle (MCA), anterior (ACA), posterior (PCA), and in affected (a), ipsilateral (i), and contralateral (c-lat) cerebral arteries. Ratios of aMCA/c-lat MCA, aMCA/iACA, and aMCA/iPCA MFV were subsequently calculated. PMD-TCD flow findings were evaluated with a receiver-operating characteristic (ROC) analysis for angiographically proven MCA occlusion. RESULTS: We studied 120 patients with acute cerebral ischemia with PMD-TCD examinations prior to or immediately after DSA. Lower aMCA velocities pointed to higher probability of occlusion (P= .055). The aMCA/iPCA MFV ratio was superior to the aMCA/iACA ratio and strongly predictive of occlusion at a threshold ratio of 0.5 (RR 2.31 CI(95) 2.13-2.51). High resistance or absent M-mode flow signatures in the proximal MCA were present in 87% of M1 and M2 MCA occlusions (probability 87%). In the presence of a low-resistance PMD signature, obtaining the aMCA/iPCA MFV ratio <0.5 increases probability of occlusion to 87%. Normal MFV ratios and low-resistance M-mode signatures are highly predictive of a negative angiogram for MCA occlusion. CONCLUSION: In acute cerebral ischemia, reliable criteria for proximal MCA occlusion have been developed based on combination of MFV ratios and M-mode flow resistance signatures. Validation of these criteria will require multicenter studies.  相似文献   
63.
癫痫手术后短期内癫痫发作病因分析及临床意义   总被引:5,自引:0,他引:5  
目的:研究癫痫手术后短期癫痫发作的原因以及对预后的判断价值。方法:回顾性分析73例患者资料,将抗癫痫药物使用情况、以及是否颞叶癫痫、是否由肿瘤引起的癫痫、是否外伤性癫痫发作作为危险因素与术后短期癫痫发作进行Logistic回归模型分析。并对所有患者进行了12个月以上的随访。手术后短期癫痫发作与患者术后长期控制结果进行χ2检验。结果:19例患者发生APOSs。手术后抗癫痫药物使用不合理可能是APOSs独立的危险因素。癫痫手术患者出现APOSs组与未出现APOSs组在术后随访的癫痫Enge分级评分中无统计学差异。结论:抗癫痫药物的使用不当可能是手术后短期癫痫发作的主要原因之一。癫痫手术后APOSs的出现不能预测患者的长期预后情况。  相似文献   
64.
急性重症胰腺炎的中西医结合非手术治疗   总被引:4,自引:2,他引:2  
目的:探讨中西医结合非手术治疗急性重症胰腺炎的疗效.方法:同期设治疗组和对照组,两组均给予西医综合治疗,治疗组加用中医中药.结果:治疗组治愈率81.25%,中转手术率4.17%,2~3周后手术处理后遗症率8.33%,病死率6.25%.对照组治愈率40.74%,中转手术率11.11%,2~3周后手术处理后遗症率18.52%,病死率29.63%.均有显著性差异.结论:中西医结合治疗疗效确切,并有降低死亡率、减少并发症、缩短病程等优点.  相似文献   
65.
Mycophenolate mofetil (MMF) used in a triple-drug regimen has been shown to decrease acute rejection rates, compared to a double-drug regimen. The impact of MMF on late acute rejection (LAR) episodes has not been well described. To investigate the risk of LAR (rejection > or = 6 months post-transplantation) data from the Scientific Registry of Transplant Recipients (SRTR) were used. We studied adult primary liver transplant recipients transplanted between June 1, 1995, and April 30, 2004, with hepatitis C virus (HCV) (n = 3356), hepatitis B virus (HBV) (n = 550) or a nonviral (n = 5740) primary cause of liver disease who were recorded as receiving continuous 3-(MMF + Tacro + steroids) versus 2-drug (Tacro + steroids) therapy for at least 6 months immediately post transplantation. Kaplan-Meier analysis showed significantly lower LAR rates 4 years post-transplant in 3- versus 2-drug HCV, HBV and nonviral disease patients. Multivariate regression confirmed 3- versus 2-drug therapy to be associated with a decreased risk of LAR. Late graft survival was significantly lower at 4 years post-transplant for patients with LAR 6-12 months post-transplantation versus patients with early rejection (78.0% vs. 87.0%, p < 0.001) and no rejection (88.1%, p < 0.001). Three-drug versus 2-drug therapy for a minimum of 6 months may offer a better treatment strategy to avoid the consequences and expense of LAR episodes.  相似文献   
66.
BACKGROUND: Diffuse peritubular capillary (PTC) C4d deposition has been shown to be associated with relatively poor graft outcome. The significance of focal PTC C4d staining in the early post-transplant period is uncertain. METHODS: Sixty-five biopsies from 53 patients with acute rejection were graded (Banff '97 criteria), stained for C4d, monocytes and T cells, and divided into three groups according to PTC C4d: (i) focal C4d (F) (14 biopsies, 14 patients), (ii) diffuse C4d (D) (23 biopsies, 15 patients) and (iii) no C4d (N) (28 biopsies, 24 patients). The three groups were compared with respect to a variety of biopsy and clinical parameters including outcome. RESULTS: The incidence of transplant glomerulitis and glomerular monocyte infiltration were significantly greater in F (64% and 2.0+/-2.0) and D (57% and 3.4+/-2.0) than in N (11% and 0.2+/-0.2). A significantly higher proportion of F (93%) demonstrated acute cellular rejection (Banff '97 grade > or = 1A) than did D (35%). The F and D groups included significantly more females (50 and 67%, respectively) than did N (21%). The percentage of patients with a second or third transplant was higher in F (29%) and D (40%) than in N (8%) (P = 0.0589). The proportion of patients with glomerular filtration rate < 30 ml/min at 12, 24 and 48 months was higher in the D and F groups than in the N, and there was a statistically significant increasing trend in odds of this outcome occurring at 48 months across the three groups (D > F > N group) (P = 0.0416). CONCLUSION: The results suggest that the biopsy findings and clinical course in patients with focal PTC C4d staining are similar to those associated with diffuse C4d.  相似文献   
67.
目的评价定期骨髓象检查对急淋诱导化疗的指导意义。方法对引例初治成人急淋患音,于诱导化疗首疗程期间定时作骨髓象观察,用这两个时限的骨髓白血病细胞比率及/或白血病细胞减少指数指导化疗。结果本组完全缓解(CR)率82.4%(42/51),其中首疗程CR率60.8%(31/51)。结论诱导化疗期定时骨髓象观察指导化疗有助于提高急淋CR率及首疗程CR率。  相似文献   
68.
本文首次报道采用253kPa的高压氧治疗24例创伤后筋膜间隔综合征(PACS)病人并采用免疫单扩散法检测了治疗前后血浆纤粘素(FN)的变化与预后的关系。30例健康人作为血浆FN的对照组。结果表明:16例早期PACS病人,经3~5次高压氧治疗,症状和体征逐渐好转,无1例作筋膜切开减压。6例筋膜切开减压后行高压氧治疗者,水肿、炎症消退,体温降低,临床症状好转。2例坏死期PACS虽然临床症状好转,但效果差。高压氧治疗后,病人血浆FN显著高于治疗前。分别较治疗前高43(18.9%;P<0.01)、61(24.7%;P<0.01)、49(17.2%;P<0.01)、57(17.4%;P<0.05)和55mg/L(16.6%;P<0.05)。根据本组研究的结果,提示高压氧是治疗早期PACS的有效非手术疗法和筋膜减压后有效辅助疗法。  相似文献   
69.
The efficacy and safety of ketoprofen and paracetamol were compared for the treatment of acute migraine in a randomized, double-blind study of 64 patients. Thirty-four patients received ketoprofen 100 mg intramuscularly, and 30 patients received paracetamol 500 mg intramuscularly. Partial or complete relief of pain and other symptoms was achieved 15 to 20 minutes after administration in the ketoprofen group and within 35 minutes in the paracetamol group. Complete relief of pain was achieved within 30 to 40 minutes after ketoprofen in 28 patients (82.5%) compared to 5 patients (17.5%) in the paracetamol group. Six of the patients treated with ketoprofen needed a second dose for complete relief of pain during the 4-hour follow-up period. Side effects were rare and minimal. Our findings suggest that ketoprofen produced statistically significant benefit in the treatment of acute migraine.  相似文献   
70.
Two infants with biliary atresia who exhibited three-fold increased trough levels of tacrolimus and required reduced doses during episodes of acute infantile diarrhea within 5 months of liver transplantation are described. The cause of the increase was not explained simply by hemoconcentration as a result of significant loss of extracellular fluid during these episodes. It does highlight an important issue: that of the continuing need to carefully monitor the trough levels of tacrolimus in such infants.  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