全文获取类型
收费全文 | 2033986篇 |
免费 | 138619篇 |
国内免费 | 4039篇 |
专业分类
耳鼻咽喉 | 28274篇 |
儿科学 | 67670篇 |
妇产科学 | 55871篇 |
基础医学 | 291067篇 |
口腔科学 | 57115篇 |
临床医学 | 181121篇 |
内科学 | 385973篇 |
皮肤病学 | 47326篇 |
神经病学 | 159522篇 |
特种医学 | 80992篇 |
外国民族医学 | 517篇 |
外科学 | 308115篇 |
综合类 | 43161篇 |
现状与发展 | 1篇 |
一般理论 | 646篇 |
预防医学 | 147951篇 |
眼科学 | 47439篇 |
药学 | 154720篇 |
9篇 | |
中国医学 | 4610篇 |
肿瘤学 | 114544篇 |
出版年
2018年 | 22042篇 |
2017年 | 17249篇 |
2016年 | 20068篇 |
2015年 | 22517篇 |
2014年 | 29934篇 |
2013年 | 44548篇 |
2012年 | 60808篇 |
2011年 | 63880篇 |
2010年 | 37954篇 |
2009年 | 35089篇 |
2008年 | 59795篇 |
2007年 | 64060篇 |
2006年 | 64957篇 |
2005年 | 62731篇 |
2004年 | 60557篇 |
2003年 | 58245篇 |
2002年 | 56212篇 |
2001年 | 99926篇 |
2000年 | 102394篇 |
1999年 | 85777篇 |
1998年 | 22881篇 |
1997年 | 20209篇 |
1996年 | 20007篇 |
1995年 | 18961篇 |
1994年 | 17409篇 |
1993年 | 16388篇 |
1992年 | 65603篇 |
1991年 | 63529篇 |
1990年 | 62652篇 |
1989年 | 60383篇 |
1988年 | 54645篇 |
1987年 | 54095篇 |
1986年 | 50646篇 |
1985年 | 48320篇 |
1984年 | 35707篇 |
1983年 | 30110篇 |
1982年 | 17377篇 |
1981年 | 15439篇 |
1979年 | 32572篇 |
1978年 | 22690篇 |
1977年 | 19842篇 |
1976年 | 17964篇 |
1975年 | 19674篇 |
1974年 | 23236篇 |
1973年 | 22501篇 |
1972年 | 21136篇 |
1971年 | 19777篇 |
1970年 | 18242篇 |
1969年 | 17356篇 |
1968年 | 15821篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
M Müller J Grunewald C Olgart H?glund B Dahlén A Eklund H Stridh 《The European respiratory journal》2006,28(3):513-522
The increased number of lymphocytes in airways during an asthmatic response is believed to be the result of increased recruitment of these cells. However, it is possible that a decreased apoptotic rate could also contribute to the increased number. The aim of the present study was to investigate whether allergen airway provocation influences the apoptotic phenotype of lung and peripheral blood lymphocytes (PBL) in subjects with atopic asthma. Bronchoalveolar lavage (BAL) lymphocytes and PBL from 12 asthmatic subjects previously challenged with allergen (n = 7) or saline (n = 5) were exposed to the apoptotic stimulus tributyltin (TBT) in vitro and assayed for apoptosis. Airway allergen provocation resulted in decreased sensitivity of BAL lymphocytes to TBT-induced apoptosis, with 42.2% (range 33.9-62.5%) apoptotic cells before challenge versus 23.5% (range 15.3-42.4%) after challenge, while PBL were unaffected. The increased apoptosis resistance correlated with higher numbers of Bcl-2-expressing lymphocytes. Interestingly, baseline caspase-3-like activity was significantly elevated in viable BAL lymphocytes compared with viable PBL, and was unaltered by allergen exposure. In conclusion, allergen inhalation renders bronchoalveolar lavage lymphocytes more resistant to apoptosis while peripheral blood lymphocytes were not influenced at all, indicating that the apoptotic phenotype of airway lymphocytes may play a role in asthmatic inflammation. 相似文献
62.
K. Dahan V. Audard F. Roudot-Thoraval D. Desvaux M. Abtahi H. Mansour M. Kumal P. Lang P. Grimbert 《American journal of transplantation》2006,6(7):1725-1730
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis. 相似文献
63.
64.
S Balzer D T Schneider M B Bernbeck M J?ger O Mils J Schaper R Willers R Krauspe U G?bel R Wessalowski 《International journal of hyperthermia》2006,22(6):451-461
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads. 相似文献
65.
A 17-year-old man presented with signs of peritonitis. Laparotomy revealed gangrene of the stomach without obvious cause. The patient underwent total gastrectomy with esophago-jejunal anastomosis with formation of jejunal pouch. Bacterial culture of the peritoneal fluid grew Strept. pyogenes and E. coli. The patient was discharged on day 21 after a stormy postoperative course. 相似文献
66.
67.
Ohne Zusammenfassung 相似文献
68.
69.
K P Sylvester S R Desai A U Wells D M Hansell M Awogbade S L Thein A Greenough 《The European respiratory journal》2006,28(4):832-838
The aim of this study was to determine whether patients with sickle cell disease (SCD) in steady state had pulmonary abnormalities seen on high-resolution computed tomography (HRCT) and whether any abnormalities correlated with contemporaneously diagnosed lung function abnormalities. A subsidiary question was whether the results of a noninvasive measure of haemolysis (end-tidal carbon monoxide (ETCO) levels) correlated with pulmonary function abnormalities. Thirty three patients with SCD, median (range) age 36 yrs (17-67 yrs) were examined. The degree of lobar volume loss and ground-glass opacification and prominence of central vessels on HRCT were quantitatively assessed. Pulmonary function was assessed by measurements of lung volumes, spirometry, gas transfer and oxygen saturation. ETCO levels were measured using an end-tidal CO monitor. Forced expiratory volume in one second (FEV1), forced vital capacity and total lung capacity significantly correlated with HRCT findings, particularly lobar volume loss. ETCO levels significantly negatively correlated with FEV1, vital capacity measured using a plethysmograph, specific airway conductance and arterial oxygen saturation measured by pulse oxymetry. In conclusion, the present results suggest that high-resolution computed tomography noninvasive assessment of haemolysis might be useful to identify sickle cell disease patients with respiratory function impairment. 相似文献
70.
R H Green C E Brightling S McKenna B Hargadon N Neale D Parker C Ruse I P Hall I D Pavord 《The European respiratory journal》2006,27(6):1144-1151
There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation. 相似文献