全文获取类型
收费全文 | 1745739篇 |
免费 | 126530篇 |
国内免费 | 4829篇 |
专业分类
耳鼻咽喉 | 22645篇 |
儿科学 | 56962篇 |
妇产科学 | 47517篇 |
基础医学 | 264070篇 |
口腔科学 | 48120篇 |
临床医学 | 164628篇 |
内科学 | 331452篇 |
皮肤病学 | 36371篇 |
神经病学 | 140496篇 |
特种医学 | 63225篇 |
外国民族医学 | 422篇 |
外科学 | 247186篇 |
综合类 | 36155篇 |
现状与发展 | 1篇 |
一般理论 | 568篇 |
预防医学 | 145585篇 |
眼科学 | 39145篇 |
药学 | 131032篇 |
6篇 | |
中国医学 | 4023篇 |
肿瘤学 | 97489篇 |
出版年
2019年 | 14263篇 |
2018年 | 19882篇 |
2017年 | 15014篇 |
2016年 | 16346篇 |
2015年 | 18624篇 |
2014年 | 25551篇 |
2013年 | 39542篇 |
2012年 | 54098篇 |
2011年 | 57787篇 |
2010年 | 33637篇 |
2009年 | 31001篇 |
2008年 | 53418篇 |
2007年 | 56543篇 |
2006年 | 56956篇 |
2005年 | 54867篇 |
2004年 | 52656篇 |
2003年 | 50103篇 |
2002年 | 48736篇 |
2001年 | 79326篇 |
2000年 | 81851篇 |
1999年 | 68311篇 |
1998年 | 18958篇 |
1997年 | 17050篇 |
1996年 | 17133篇 |
1995年 | 16182篇 |
1994年 | 15092篇 |
1993年 | 14239篇 |
1992年 | 53924篇 |
1991年 | 53507篇 |
1990年 | 52373篇 |
1989年 | 49912篇 |
1988年 | 46241篇 |
1987年 | 45220篇 |
1986年 | 43070篇 |
1985年 | 41128篇 |
1984年 | 30823篇 |
1983年 | 26257篇 |
1982年 | 15465篇 |
1979年 | 28480篇 |
1978年 | 20400篇 |
1977年 | 16790篇 |
1976年 | 16433篇 |
1975年 | 17346篇 |
1974年 | 21043篇 |
1973年 | 20333篇 |
1972年 | 19185篇 |
1971年 | 18050篇 |
1970年 | 16679篇 |
1969年 | 15427篇 |
1968年 | 14624篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Anne Pavy-Le Traon Richard L Hughson Claire Thalamas Monique Galitsky Nelly Fabre Olivier Rascol Jean-Michel Senard 《Movement disorders》2006,21(12):2122-2126
Patients with multiple system atrophy (MSA) present large changes in blood pressure (BP) due to autonomic disturbances. We analyzed how this change may influence dynamic cerebral autoregulation (DCA). Simultaneous recordings of arterial BP (Finapres) and middle cerebral artery (MCA) blood flow velocity (BFV) (transcranial Doppler) were performed in 10 patients with MSA (61 +/- 12 yr of age) and 12 healthy volunteers (61 +/- 11 yr of age): cerebral BFV response to oscillations in mean BP was studied in the supine position by cross-spectral analysis of mean BP and mean MCA BFV. The DCA was also studied during the decrease in BP the first seconds when standing up from a sitting position by the assessment of the cerebrovascular resistance index (CR; mean BP/mean MCA BFV ratio). The MCA BFV/BP cross-spectral analysis showed a phase for the mid-frequency band (0.07-0.2 Hz) significantly larger in MSA, suggesting more active autoregulation in response to larger changes in BP. Changes in CR reflecting the rate of autoregulation, when standing did not differ between the two groups. These data suggest that dynamic cerebral autoregulation is preserved in MSA. 相似文献
52.
53.
Published data devoted to making and characterization of the properties of polymeric wound dressings with proteolytic action
are reviewed. These data are indicative of individual dependence of the physicochemical properties, activity, and stability
of each particular enzyme on the type of polymer matrix and the method of immobilization. In order to obtain wound dressings,
which are active in physiological medium and retain their activity upon sterilization, it is necessary to optimize the composition
and characteristics of a polymer matrix and the enzyme included into its structure.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 8, pp. 24–28, August, 2006. 相似文献
54.
55.
D Yinon L Lowenstein S Suraya R Beloosesky O Zmora A Malhotra G Pillar 《The European respiratory journal》2006,27(2):328-333
Pre-eclamptic toxaemia (PET) may be associated with both endothelial dysfunction (ED) and sleep-disordered breathing (SDB). It was hypothesised that females with PET would demonstrate both SDB and ED, and that a correlation between these two would suggest a potential causative association. A total of 17 females with PET and 25 matched females with uncomplicated pregnancy were studied. They underwent a nocturnal ambulatory sleep study (using Watch_PAT100) and noninvasive evaluation of endothelial function utilising the reactive hyperaemia test (using Endo_PAT 2000). A higher ratio of post- to pre-occlusion pulse-wave amplitude (endothelial function index (EFI)) indicated better endothelial function. Females with PET had a significantly higher respiratory disturbance index (RDI) and lower EFI than controls (18.4+/-8.4 versus 8.3+/-1.3.h(-1), and 1.5+/-0.1 versus 1.8+/-0.1, respectively). Blood pressure significantly correlated with RDI and with EFI. EFI tended to correlate with RDI. In conclusion, these results suggest that both sleep-disordered breathing and endothelial dysfunction are more likely to occur in females with pre-eclamptic toxaemia than in females with uncomplicated pregnancies. The current authors speculate that respiratory disturbances contribute to the functional abnormality of the blood vessels seen in females with pre-eclamptic toxaemia, although causality cannot be determined based on this study. 相似文献
56.
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
57.
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
58.
J Müller-Quernheim K I Gaede E Fireman G Zissel 《The European respiratory journal》2006,27(6):1190-1195
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders. 相似文献
59.
Antony E. Shrimpton Robert L. Schelper Reinhold P. Linke John Hardy Richard Crook Dennis W. Dickson Takashi Ishizawa Richard L. Davis 《Neuropathology》2007,27(3):228-232
Over 100 mutations in the presenilin‐1 gene (PSEN1) have been shown to result in familial early onset Alzheimer disease (EOAD), but only a relatively few give rise to plaques with an appearance like cotton wool (CWP) and/or spastic paraparesis (SP). A family with EOAD, seizures and CWP was investigated by neuropathological study and DNA sequencing of the PSEN1 gene. Aβ was identified in leptomeningeal vessels and in cerebral plaques. A single point mutation, p.L420R (g.1508T > G) that gives rise to a missense mutation in the eighth transmembrane (TM8) domain of PS1 was identified in two affected members of the family. p.L420R (g.1508T > G) is the mutation responsible for EOAD, seizures and CWP without SP in this family. 相似文献
60.
S Aquilina† M Dalmas‡ N Calleja§ P Gatt† L Scerri† 《Journal of the European Academy of Dermatology and Venereology》2006,20(8):958-963
BACKGROUND: The incidence of malignant melanoma of the skin has risen in every part of the world where reliable cancer registration data are found. OBJECTIVE: Our study aims to describe the changing incidence of and survival from invasive cutaneous malignant melanoma in Malta, by analysing the data from the 211 cases that were registered at the Malta National Cancer Registry between 1993 and 2002. RESULTS: The age standardized incidence rates for invasive cutaneous malignant melanoma rose from 3.7 per 100,000 population per year for males and 5.1 for females in the first 5-year period, to 8.0 per 100,000 population per year for males and 5.9 for females in the second 5-year period. In both sexes, numbers of thin (< or = 1.0 mm) invasive melanomas increased significantly between 1993 and 2002; males also registered a significant increase in intermediate-thickness (1.01-4.0 mm) melanomas. The increase in numbers of thin and intermediate-thickness melanomas between the two 5-year periods was greatest in patients aged 60 years and over. The overall absolute 5-year survival rate for the first period was 74% and for the second period 92%. CONCLUSION: Numbers of reported cases of invasive cutaneous malignant melanoma in Malta have more than doubled during the 10-year study period. This is mostly due to a marked rise in the diagnosis of thin melanomas in both sexes, occurring mainly in patients aged 60 years and over. As thin melanomas are of low metastasizing potential, this has resulted in an increase in survival between the two 5-year study periods. 相似文献