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   24550篇
  免费   1947篇
  国内免费   360篇
耳鼻咽喉   670篇
儿科学   524篇
妇产科学   359篇
基础医学   2436篇
口腔科学   235篇
临床医学   3543篇
内科学   3865篇
皮肤病学   112篇
神经病学   1245篇
特种医学   1992篇
外国民族医学   1篇
外科学   3448篇
综合类   3210篇
预防医学   1028篇
眼科学   211篇
药学   1795篇
  18篇
中国医学   341篇
肿瘤学   1824篇
  2024年   54篇
  2023年   389篇
  2022年   745篇
  2021年   1100篇
  2020年   1076篇
  2019年   911篇
  2018年   958篇
  2017年   891篇
  2016年   913篇
  2015年   902篇
  2014年   1737篇
  2013年   1659篇
  2012年   1379篇
  2011年   1507篇
  2010年   1238篇
  2009年   1168篇
  2008年   1104篇
  2007年   1104篇
  2006年   979篇
  2005年   803篇
  2004年   664篇
  2003年   580篇
  2002年   433篇
  2001年   415篇
  2000年   339篇
  1999年   325篇
  1998年   299篇
  1997年   283篇
  1996年   238篇
  1995年   229篇
  1994年   222篇
  1993年   208篇
  1992年   174篇
  1991年   162篇
  1990年   175篇
  1989年   154篇
  1988年   151篇
  1987年   118篇
  1986年   117篇
  1985年   130篇
  1984年   134篇
  1983年   95篇
  1982年   123篇
  1981年   77篇
  1980年   57篇
  1979年   57篇
  1978年   64篇
  1977年   48篇
  1976年   42篇
  1975年   29篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Accurate assessment and replacement of blood loss and fluid–electrolyte deficit during craniosynostosis repair is difficult owing to patient size and the diversity of surgical technique. Forty-three patients undergoing primary craniosynostosis repair over a 10-year period were studied retrospectively to determine blood loss and fluid deficit and to assess blood transfusion practices during both intraoperative and postoperative periods. Blood loss was calculated on the basis of estimated red cell mass (ERCM) and fluid-electrolyte imbalance was investigated with blood samplings. Blood transfusion was considered appropriate if the postoperative or posttransfusion ERCM was within 12% of the preoperative value. Estimated fluid requirement (EFR) was used in 4 ml kg–1 h–1 except for neonates. Intraoperatively, 80% of all patients were appropriately managed with respect to blood transfusion and EFR. Postoperatively only 20% of the patients receiving transfusions were transfused appropriately. In 23.3% of these patients (10/43) unexpected respiratory distress developed immediately after their recovery from the anesthesia. With the measurement of estimated blood volume and allowable blood loss, appropriate transfusion could be achieved for the successful treatment of the primary craniosynostosis. Received: 16 February 1998  相似文献   
52.
碘过量与甲状腺疾病   总被引:8,自引:0,他引:8  
介绍近年来国内外对高碘致甲状腺肿、甲状腺功能亢进症、甲状腺功能减退症、自身免疫甲状腺炎、甲状腺癌的研究进展,阐述防治碘缺乏病(IDD)应当因地因人分类设计,盲目补碘和过度补碘都是错误的。  相似文献   
53.
分化型甲状腺癌术后 131I治疗对复发的影响   总被引:6,自引:0,他引:6  
目的 探讨分化型甲状腺癌 (DTC)术后复发的影响因素。方法 DTC术后随访患者 3组 :1组 2 98例 ,均为术后复发患者 ,分析首诊年龄、性别、术式、病理类型等因素对复发的影响 ;2组10 8例 ,为术后行甲状腺素替代治疗的患者 ;3组 12 4例 ,为术后行甲状腺素替代 1 31 I清除甲状腺剩余组织治疗的患者。进行后两组间年复发率对照分析。结果 ① 1组DTC复发患者性别男、女之比(1∶1 5 )和病理类型滤泡状、乳头状癌之比 (1∶4 )均高于文献 (1∶2~ 3和 1∶8) ;原发灶甲状腺癌肿块切除、甲状腺单侧腺叶切除和双侧腺叶切除者复发百分率依次降低 (分别为 4 7 3%、34 2 %和 18 5 % ) ;复发多出现于术后 5年内 (6 5 1% ) ;复发部位以颈淋巴结居多 (2 3 5 % )。② 2组DTC术后 1、5和 10年复发率分别为 4 6 3%、8 33%和 12 0 4 % ,5 3 85 % (7 13例 )发生在术后 2年内 ,近端和远端复发分别占 5 3 84 %和 30 77% ;3组 1、5、10年复发率分别为 0 81%、4 0 3%和 7 2 6 % ,5 9例发生在术后 4年内 ,近端和远端复发分别为 5 9例和 2 9例。两组间差异有显著性 (P <0 0 5 )。结论 DTC首诊年龄、性别、术式、病理类型等对术后复发有一定影响 ;DTC术后行甲状腺素替代 1 31 I清除甲状腺剩余组织治疗可改善DTC预后 (延  相似文献   
54.
Digital volume tomography (DVT) is an extension of panoramic tomography. With this diagnostic technique, characterized by high resolution, a narrow section width (0.125 mm) and three-dimensional display, small pathological processes can be well visualized. Twenty-five patients with the history of a progressive hearing loss were examined with DVT (Accu-I-tomo, Morita, Japan). The results were compared with pre- and intraoperative findings to evaluate the diagnostic value of DVT in cases of erosion of the ossicular chain. With high resolution and artifact-free demonstration of the middle ear and the ossicular chain, it was possible to define its continuity preoperatively by DVT in all 25 cases. An intact ossicular chain was found by DVT in 13 cases and was later confirmed by surgery. The predicted erosion of the ossicles was verified in 12 patients, and a tympanoplasty type III was performed. Digital volume tomography is an excellent technique to examine the middle ear cleft and inner ear, and expands the application of diagnostic possibilities in the lateral skull base. Therefore, improvement in preoperative diagnosis is achieved along with more accurate planning of the surgical procedure. Digital volume tomography delivers a small radiation dose with a high resolution and a low purchase price for the equipment.  相似文献   
55.
本文报道242例高脂血症患者血小板(PLT)、平均血小板数(MPLT)及平均血小板体积(MPV)等参数的测定结果,其中高胆固醇并高甘油三酯患者,PLT、MPLT及巨大血小板比例(Macro-PLT)高于正常,MPV正常;而单纯高胆固醇或高甘油三酯患者,上述指标与正常人无显著性差异。提示高胆固醇并高甘油三酯患者,存在血小板生成动力学异常,其血小板的破坏增加,生成率加速、但处于一种高水平的动态平衡之中。这可能是高脂血症出现高凝状态的原因之一。同时表明此类患者使用抗血小板疗法具有一定的合理性和必要性。  相似文献   
56.
Prof. Dr.  O. P. Steeno 《Andrologia》1989,21(2):103-112
Summary: For the quantitative determination of the testicular size or volume, two groups of apparatus are available: on the one hand, model testes, which are extremely valuable in longitudinal and cross-sectional studies during the period of pubescence, and on the other hand, measuring devices, with which the testicular dimensions can be specified. The latter instruments are helpful chiefly during the adolescent years and the diagnosis of problems surrounding fertility. The testicular volume can be calculated subsequently from the specific testicular measurements. The formula, for computing the volume of an ellipsoid, seems to be the most suitable for this purpose. Appliances also have been developed, which allow the largest (longitudinal) dimension (in mm) and the testicular volume (in cm3) to be read off simultaneously. A tonometer can be useful to quantitatively estimate the testicular consistency, which is a parameter of the testicular integrity at the level of tubular function (spermatozoa production).  相似文献   
57.
Summary A system which can be used for injection or infiltration of large volumes of fluid is described. This consists of a syringe which fills automatically from a reservoir through an inlet/outlet valve.  相似文献   
58.
甲状腺癌是临床和病理易于误诊的恶性瘤之一,高分化甲状腺癌与甲状腺腺瘤很难鉴别,甲状腺癌的组织学分类和病理诊断标准至今尚未统一。本文根据50例甲状腺癌的临床病理分析,参阅有关文献,对甲状腺癌的诊断标准、鉴别诊断和地方性甲状腺肿与癌的关系进行讨论。  相似文献   
59.
Chronic nasal obstruction in children is a very common disorder. Obstructing adenoid is usually the first to blame. Though the clinical assessment is essential, it is often considered unreliable or insufficient. We conducted a prospective clinical study to validate a clinical score predicting the severity of adenoid obstruction in symptomatic children. The clinical score (CS) included mouth breathing, snoring, restless sleep, frequent waking-up at night and obstructive breathing during sleep. Each item received a score of 0 or 1. The palatal airway was evaluated on a lateral nasopharyngeal x-ray. The degree of obstruction was assessed intra-operatively by a laryngeal mirror using a 3-grade scale. The volume of each adenoid specimen was measured. Eighty-six patients were enrolled, 51 boys and 35 girls, aged 13–181 months (mean 52, median 45). The CS correlated very well with the intra-operative findings (p < 0.01) and with the degree of palatal airway obstruction (p < 0.05) but not with the volume of the adenoid removed (p > 0.05). The CS was higher in children younger than 3 years (CS > 3 in 85.7% vs. 29.2%), having more frequent obstructive breathing during sleep (71.43% vs. 21.54%). A CS of three or higher, predicted severe obstruction in 96.5% of patients, as detected intra-operatively. The suggested CS is simple to use and is highly reliable in identifying children in need for adenoidectomy, in the context of normal anterior rhinoscopy and tonsils less than grade three.This work was presented at the podium of the XVIII IFOS in Rome, Italy on June 26, 2005.  相似文献   
60.
内科微创肺减容术的研究进展   总被引:1,自引:0,他引:1  
传统的外科肺减容术治疗慢性阻塞性肺疾病(COPD)有严格的适应证,并且副作用大、并发症多。于是人们研究出多种基于同样原理但是采用内科微创技术的减容方法。目前常用的内科微创肺减容术有使用单向活瓣、生物蛋白胶等封堵支气管使靶肺萎陷、不张,或采用支气管内药物灌注肺泡加封堵使靶肺组织纤维化等。此外,还有人提出人工旁路增加呼出气量的方法。尽管目前还缺少大规模的随机对照临床试验结果,但是内科微创肺减容术已展现了其巨大的临床应用前景,也将为治疗COPD提供更多的选择。  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