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   1322篇
  免费   78篇
  国内免费   5篇
耳鼻咽喉   15篇
儿科学   28篇
妇产科学   33篇
基础医学   137篇
口腔科学   21篇
临床医学   189篇
内科学   208篇
皮肤病学   17篇
神经病学   96篇
特种医学   91篇
外科学   219篇
综合类   26篇
一般理论   1篇
预防医学   81篇
眼科学   45篇
药学   135篇
中国医学   9篇
肿瘤学   54篇
  2024年   2篇
  2023年   17篇
  2022年   34篇
  2021年   53篇
  2020年   42篇
  2019年   66篇
  2018年   64篇
  2017年   48篇
  2016年   50篇
  2015年   45篇
  2014年   58篇
  2013年   94篇
  2012年   91篇
  2011年   107篇
  2010年   72篇
  2009年   72篇
  2008年   75篇
  2007年   46篇
  2006年   47篇
  2005年   41篇
  2004年   44篇
  2003年   39篇
  2002年   38篇
  2001年   26篇
  2000年   18篇
  1999年   7篇
  1998年   6篇
  1997年   3篇
  1996年   3篇
  1995年   8篇
  1993年   2篇
  1992年   4篇
  1991年   3篇
  1990年   3篇
  1989年   8篇
  1988年   12篇
  1987年   7篇
  1986年   6篇
  1985年   8篇
  1984年   3篇
  1983年   6篇
  1982年   3篇
  1981年   2篇
  1979年   7篇
  1978年   2篇
  1975年   4篇
  1974年   2篇
  1968年   1篇
  1967年   2篇
  1966年   1篇
排序方式: 共有1405条查询结果,搜索用时 15 毫秒
11.
Abstract:  Using lacerated livers for liver transplantation (LTx) can add an option to the extended donor criteria. We present an LTx case using a severely lacerated liver and review of the literature for reported cases. We used a high-grade lacerated liver from a 19-yr-old brain-dead patient caused by traffic accident. The liver had grade IV and II lacerations in the right and left lobe, respectively. Lacerations were managed by sealants, stitching and perihepatic packing. The liver was transplanted to a 49-yr-old man suffering from hepatocellular carcinoma on hepatitis C-induced liver cirrhosis. The two-yr follow-up was uneventful. All published LTx cases using traumatized livers (n = 18) were analyzed. The liver injury ranged from subcapsular hematoma to deep ruptures. Most reported lacerations were in the right lobe, which were managed by digital compression, suturing, electrocautery, and perihepatic packing. The reported complications were primary non- (18%), or poor function, liver abscess, bilioma, and subhepatic hematoma each in one case (5.5%). Six-month graft and patient survival were 71% and 88%, respectively. With meticulous management lacerated livers can be transplanted successfully. Because of complexity of the management, procurement and transplantation should be done by experienced liver surgeons. These organs are marginal grafts and should be offered to selected patients.  相似文献   
12.
Phosphorus-containing compounds are one of the most important classes of organic compounds, which have wide applications in organic chemistry, medicinal chemistry, agricultural chemistry, and materials chemistry. In particular, organophosphorus compounds bearing a P(O)–C bond have attracted significant attention in recent decades due to their widespread biological and pharmacological activities. In this review, we will highlight the most important developments in the construction of P(O)–C bonds through decarboxylative C–P cross-coupling reactions. The literature has been surveyed from 2011 to May 2018.

Phosphorus-containing compounds are one of the most important classes of organic compounds, which have wide applications in organic chemistry, medicinal chemistry, agricultural chemistry, and materials chemistry.  相似文献   
13.
14.
PURPOSE: To examine if excessive in-stent neointimal formation causing a subcritical stenosis may indicate enhanced vascular reactivity in response to injury, thus predicting late cardiovascular events. METHODS: One hundred consecutive patients (64 men; median age 71 years) with high-grade internal carotid artery stenoses (68 asymptomatic, 32 symptomatic) underwent carotid artery stenting (CAS). High-sensitivity C-reactive protein (hs-CRP) was measured before CAS. Patients were monitored with duplex ultrasound for excessive in-stent neointimal formation (flow-compromising lumen diameter reduction >/=50%), critical restenosis (>/=70%), or the occurrence of late major adverse cardiovascular events (MACE) defined as myocardial infarction (MI), stroke, and death occurring later than 30 days poststenting. RESULTS: Over a median 23-month follow-up, excessive neointimal formation was observed in 14 (14%) patients, restenosis in 2 (2%), and 30 late MACE in 25 [25%: 4 MIs, 2 ipsilateral strokes (in the patients with restenosis), 8 contralateral strokes, and 16 cardiovascular deaths]. Cumulative MACE-free survival rates at 6, 12, and 24 months were 92%, 84%, and 77%, respectively. Baseline hs-CRP levels were associated both with neointimal hyperplasia (p=0.024) and MACE (p=0.021). Patients with excessive neointimal formation exhibited a significantly increased adjusted risk for MACE (hazard ratio 3.56, p=0.010). CONCLUSIONS: Excessive in-stent neointimal formation after CAS indicates an increased risk for late MACE, potentially reflecting a state of exaggerated vascular reactivity in response to injury. Inflammation, which is associated both with neointimal hyperplasia and MACE, seems a common characteristic of different vascular pathologies.  相似文献   
15.
Currently there are no growth charts based on local norms available for infants in Iran, and their growth is assessed by the National Centre for Health Statistics (NCHS) reference data, which is misleading. Growth charts for a cohort of 317 infants (164 girls and 153 boys) born in Shiraz (Southern Iran) in 1996 and followed for 2 years from birth are presented. All the centiles of length and weight charts are slightly above those of the NCHS charts under the age of 6 months and fall substantially below those over the age of 6 months. However, the spread is similar, so there is no suggestion that the difference is due to the prevalence of gross malnutrition. The difference shows that the use of locally based growth charts are essential for assessing the growth of children in Iran. The representativeness of our data leads us to conclude that the charts presented here are likely to be applied to the urban infant population of Iran.

Gegenwärtig stehen im Iran für Kleinkinder keine auf lokalen Normdaten basierende Wachstumsdiagramme zur Verfügung. Das Wachstum dieser Kinder wird anhand der Referenzdaten des Nationalen Zentrums für Gesundheitsstatistik (NCHS) eingeschätzt, was zu Fehleinschätzungen führt. Es werden Wachstumsdiagramme für eine Kohorte von 317 Kleinkindern (164 Mädchen und 153 Jungen) vorgestellt, die 1996 in Shiraz (Südiran) geboren wurden und nach ihrer Geburt 2 Jahre lang untersucht wurden. Alle Längen- und Gewichtszentilen liegen bis zu einem Alter von unter 6 Monaten leicht über denjenigen der NCHS-Diagramme und fallen ab einem Alter von 6 Monaten beträchtlich unterhalb diese. Allerdings ist die Spannweite ähnlich und daher gibt es kein Anzeichen dafür, dass der Unterschied auf das Vorliegen einer schweren Unterernährung zurückzuführen ist. Die Unterschiede zeigen, dass die Verwendung von lokalen Wachstumsdiagrammen für die Einschätzung des Wachstums von Kindern im Iran notwendig ist. Die Tatsache, dass unsere Daten als repräsentativ anzusehen sind, veranlasst uns zu der Schlussfolgerung, dass die hier vorgestellten Charts wahrscheinlich für die städtische Kleinkinderpopulation im Iran anwendbar sind.

On ne dispose pas actuellement en Iran de tables normatives de la croissance établies sur des données locales, si bien que la croissance des enfants iraniens est inadéquatement observéeen référence aux données du National Centre for Health Statistics (NCHS). On présente ici des courbes de croissance établies à partir d'une cohorte de 317 enfants (164 filles et 153 garçons) nés à Shiraz (Iran méridional) en 1996 et suivis pendant leurs deux premières années. Tous les centiles de taille et de poids sont légèrement supérieurs à ceux des tables NCHS avant l'âge de six mois, puis leurs deviennent nettement inférieurs par la suite. L'évolution des courbes étant similaire, il n'y a donc pas raison de suspecter que la différence est due à de la malnutrition. Cet écart entre les deux tables montre que l'utilisation de courbes fondées sur des données locales est essentielle pour le suivi de la croissance des enfants en Iran. La représentativité de nos données nous conduit à estimer que les tables présentées dans ce travail sont applicables à la population infantile urbaine en Iran.  相似文献   
16.
17.
A new model for prediction of the effective permeability of gases in mixed matrix membranes (MMMs), considering the effects of particle shape and the interfacial layer, is presented. The proposed model treats core filler particles and interfacial shell layers as complex particles. Moreover, the Bruggman mathematical procedure is used to improve the accuracy of the presented model for high concentrations of fillers in MMMs. Also, an appropriate uniform criterion is established to make efficient use of the new model for various experimental data to avoid the need for curve‐fitting procedures. Finally, the proposed model is examined for several sets of experimental data.

  相似文献   

18.
19.
20.
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