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   114065篇
  免费   9664篇
  国内免费   3501篇
耳鼻咽喉   593篇
儿科学   2679篇
妇产科学   986篇
基础医学   7282篇
口腔科学   1103篇
临床医学   15219篇
内科学   33261篇
皮肤病学   847篇
神经病学   2956篇
特种医学   3259篇
外国民族医学   8篇
外科学   9116篇
综合类   20958篇
现状与发展   16篇
一般理论   3篇
预防医学   6892篇
眼科学   1102篇
药学   11699篇
  98篇
中国医学   6910篇
肿瘤学   2243篇
  2024年   360篇
  2023年   2067篇
  2022年   3360篇
  2021年   4864篇
  2020年   4845篇
  2019年   4279篇
  2018年   4148篇
  2017年   4349篇
  2016年   4661篇
  2015年   4603篇
  2014年   7887篇
  2013年   9345篇
  2012年   6778篇
  2011年   7131篇
  2010年   5858篇
  2009年   5290篇
  2008年   4955篇
  2007年   5233篇
  2006年   4609篇
  2005年   4052篇
  2004年   3420篇
  2003年   3064篇
  2002年   2603篇
  2001年   2385篇
  2000年   1995篇
  1999年   1647篇
  1998年   1384篇
  1997年   1430篇
  1996年   1283篇
  1995年   1233篇
  1994年   1069篇
  1993年   816篇
  1992年   784篇
  1991年   638篇
  1990年   572篇
  1989年   493篇
  1988年   461篇
  1987年   401篇
  1986年   378篇
  1985年   504篇
  1984年   408篇
  1983年   232篇
  1982年   276篇
  1981年   273篇
  1980年   229篇
  1979年   136篇
  1978年   112篇
  1977年   104篇
  1976年   91篇
  1975年   41篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
21.
Collagenous colitis is characterized by the presence of a thick subepithelial collagen band in the colonic mucosa. The condition was diagnosed on rectal biopsy in 10 patients (one male, nine females) who presented with watery diarrhoea. Although rectal mucosal erythema was present in three and ulceration in two, the mucosa was of normal endoscopic appearance in five of the patients. There was marked variability in the thickness of the submucosal collagen band, both between and within individuals. Empirical drug therapy included sulphasalazine, glucocorticoids and antidiarrhoeals. All patients reported symptomatic improvement.  相似文献   
22.
The study explored the counterfactual thinking that women with chronic and widespread pain showed in response to what they themselves considered to be particularly stressful situations. Counterfactual thinking in 125 women sick‐listed due to chronic and widespread pain was investigated in terms of structure, function and control focus. The women were asked, for each of three types of problems that they indicated in a questionnaire to affect them most strongly, to describe a typical occurrence of it and to complete a counterfactual sentence in connection with it of the type ‘If only . . .’. The majority of counterfactuals pertained to predominantly somatic problems (e.g. musculo‐skeletal problems, pain and fatigue) classified as being affective rather than preparative and self‐focused rather than external, whereas in counterfactuals relating to predominantly psychological/psychosocial problems a preparative function and an external focus were more prominent. The numbers of problems listed and the numbers of situations responded to counterfactually were positively correlated. The counterfactuals, although often related to somatic problems, generally concerned psychological or psychosocial matters such as finances and paid or unpaid work. A contextual approach to elucidating counterfactual thinking based on subjects' own experiences is seen as providing valuable insight into what bothers them most. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
23.
The general management of patients with chronic obstructive pulmonary disease and asthma is discussed. Pathophysiological mechanisms of bronchial obstruction and inflammation are briefly described. The importance of preventive measures is emphasized. Medicine prescribed in chronic obstructive pulmonary disease and asthma, their relative place in treatment schedules and route of administration are reviewed. Finally, the importance of maximal bronchodilatation in exacerbations is stressed and the few indications for antibiotic treatment are discussed.  相似文献   
24.
X Dong  M He  X Song  B Lu  Y Yang  S Zhang  N Zhao  L Zhou  Y Li  X Zhu  R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks.  相似文献   
25.
尼莫地平联合卡维地洛治疗原发性高血压78例临床分析   总被引:1,自引:0,他引:1  
目的分析尼莫地平联合卡维地洛治疗原发性高血压的临床疗效。方法将150例原发性高血压随机分成两组,对照组给予尼莫地平治疗,治疗组在对照组治疗的基础上,加之卡维地洛。结果治疗组与对照组显效率分别为33.3%和26.4%,总有效率为88.5%和76.4%,两组相比具有显著性差异(P〈0.05)。结论尼莫地平联合卡维地洛治疗原发性高血压疗效更为显著。  相似文献   
26.
孙宁玲 《世界临床药物》2009,30(10):577-580
高血压高危患者的降压治疗既需降低血压,又需保持足够血流以保障器官灌注。血压降低过度无疑也有一定风险,因此控制皿压需要底线。高危高血压患者的个体差异大,在降压治疗过程中,临床医生既要以循证医学为鉴,叉须遵循个体化治疗原则,把握好降压幅度和速度,坚持高质量平稳降压,才能更好地保护靶器官,减少心脑血管意外的发生。  相似文献   
27.
HYPOTHESIS: Based on recent findings on the association between vascular risk factors and hippocampal atrophy, we hypothesized that hypertension and diabetes mellitus (DM) are associated with medial temporal lobe atrophy (MTA) in subjects without disability, independent of the severity of white matter hyperintensities. METHODS: In the Leukoaraiosis And DISability in the elderly (LADIS) study, we investigated the relationships between DM, hypertension, blood pressure and MTA in 582 subjects, stratified by white matter hyperintensity severity, using multinomial logistic regression. MTA was visually scored for the left and right medial temporal lobe (score 0-4), and meaned. RESULTS: Mean age was 73.5 years (sd 5.1), 54% was female. Of the subjects, 15% had DM, and 70% had a history of hypertension. The likelihood of having MTA score 3 was significantly higher in subjects with DM (OR 2.9; 95% CI: 1.1-7.8) compared with an MTA score of 0 (no atrophy). The odds ratio for MTA score 2 was not significantly increased (OR 1.8; CI: 0.9-4). Systolic and diastolic blood pressure and a history of hypertension were not associated with MTA. There was no interaction between DM and hypertension. Stratification on white matter hyperintensities (WMH) did not alter the associations. CONCLUSION: Our study strengthens the observation that MTA is associated with DM, independently of the amount of small vessel disease as reflected by WMH.  相似文献   
28.
Objective   This study evaluated the Impact on Sibling scale, a six-item measure of parents' perception of the effects of a child's illness on healthy siblings.
Methods   Participants were 122 parents of a child with chronic illness, developmental disability, or autism spectrum disorder, and a well sibling aged 4–13 years. Parents completed the Impact on Sibling scale and the Child Behavior Checklist about the sibling, and completed the revised Impact on Family scale and the Brief Symptom Inventory about themselves.
Results   The Impact on Sibling score was correlated with measures of sibling, parent and family functioning. The internal consistency of the Impact on Sibling scale was higher for families with children with chronic illness compared with the other two diagnostic groups.
Conclusion   The Impact on Sibling scale is a brief set of items that can help identify siblings who are negatively affected by a brother/sister's illness. Findings support further research on the Impact on Sibling scale, particularly with families of children with chronic illnesses.  相似文献   
29.
COPD机械通气病人下呼吸道感染致病菌分布特点   总被引:1,自引:0,他引:1  
①目的 探讨慢性阻塞性肺病(COPD)病人机械通气后下呼吸道感染致病菌的特点。②方法 取32例COPD并发呼吸衰竭行机械通气病人下呼吸道分泌物做痰细菌学培养,同时做药物敏感试验。③结果 32例病人共分离出菌株76株,阳性率71.7%,其中混合感染10例次。其中革兰阴性杆菌(GNB)58株,占76.3%;阳性球菌10株,占13.2%;真菌8株,占10.5%。常见致病菌以铜绿假单胞菌、鲍曼不动杆菌和肺炎杆菌为主,GNB中铜绿假单胞菌和不动杆菌的耐药率高。④结论 COPD应用机械通气病人下呼吸道感染以革兰阴性杆菌为主,耐药性高。  相似文献   
30.
Global coronary blood flow and metabolism were measured in seven patients on the first postoperative day following coronary revascularization to test the hypothesis that tracheal extubation produces adverse haemodynamic responses akin to those observed during tracheal intubation. Regional coronary flow and metabolic measurements were made in five of the seven patients. Extubation from a continuous positive airway pressure (CPAP) of 5 cm H2O was associated with a statistically significant rise in cardiac index from 3.44 ± 0.23 L · min-1 · m-2 to 3.73 ± 0.15L·min-1 ·m-2 related to an increase in stroke index, without significant changes in heart rate, mean arterial and pulmonary capillary wedge pressure. Consequently the changes in myocardial oxygen consumption (8.52 ± 0.55 to 8.85 ± 0.93 ml · min-1) and coronary blood flow (172 ± 18 to 179 ± 17 ml·min-1) were less prominent than those reported during intubation, where substantial rises in myocardial oxygen consumption and coronary flow occurred. Two patients experienced cardiac lactate production but there were no changes in systemic or coronary haemodynamics, nor were there clinical or electrocardiographic signs of ischaemia. We conclude that extubation does not appear to be associated with adverse systemic or coronary haemodynamic responses in patients following coronary bypass grafting. However, the revascularized myocardium may remain vulnerable to anaerobic metabolism in the immediate postoperative period. Pour savoir si comme ľintubation, ľextubation de la trachée provoque des perturbations hémodynamiques, on a mesuré le métabolisme et la circulation coronarienne globale chez sept patients, au lendemain ďun pontage aorto-coronarien. On a aussi calculé les valeurs régionales de ces mêmes variables pour cinq ďentre eux. Ľindex cardiaque de 3.44 ± 0.23 L · min-1 · m-2 sous pression positive en respiration spontanée (CPAP) de 5 cm. H2O s’est élevé à 3.73 ± 0.15 L · min-1 · m-2 post-extubation avec une augmentation significative du volume ďéjection. La fréquence cardiaque et les pressions artérielles moyennes et capillaires pulmonaires n’ont pas changé. Ainsi ľaugmentation de la consommation ďoxygène du myocarde de 8.52 ± 0.55 à 8.85 ± 0.93 ml · min-1 et celle du flot coronarien de 172 ± 18 à 179 ± 17 ml · min-1 ont été moindres que celles, importantes, déjà observées lors de ľintubation. On a noté chez deux patients une production de lactate par le myocarde, sans changement de ľhémodynamic systémique et coronarienne non plus que de signe clinique ou électrocardiographique ďischémie. Donc, après un pontage coronarien, ľextubation ne semble pas causer ďeffet néfaste sur les circulations systémique et coronarienne, toutefois, le myocarde revascularisé peut demeurer sensible au métabolisme anaérobique.  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