全文获取类型
收费全文 | 24266篇 |
免费 | 1822篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 406篇 |
儿科学 | 834篇 |
妇产科学 | 392篇 |
基础医学 | 2502篇 |
口腔科学 | 545篇 |
临床医学 | 2208篇 |
内科学 | 5318篇 |
皮肤病学 | 581篇 |
神经病学 | 1290篇 |
特种医学 | 1122篇 |
外国民族医学 | 1篇 |
外科学 | 4577篇 |
综合类 | 329篇 |
一般理论 | 16篇 |
预防医学 | 1192篇 |
眼科学 | 852篇 |
药学 | 2082篇 |
中国医学 | 41篇 |
肿瘤学 | 1878篇 |
出版年
2023年 | 226篇 |
2022年 | 423篇 |
2021年 | 1014篇 |
2020年 | 491篇 |
2019年 | 851篇 |
2018年 | 981篇 |
2017年 | 619篇 |
2016年 | 674篇 |
2015年 | 703篇 |
2014年 | 1045篇 |
2013年 | 1217篇 |
2012年 | 1818篇 |
2011年 | 1772篇 |
2010年 | 895篇 |
2009年 | 832篇 |
2008年 | 1312篇 |
2007年 | 1233篇 |
2006年 | 1153篇 |
2005年 | 1013篇 |
2004年 | 901篇 |
2003年 | 758篇 |
2002年 | 665篇 |
2001年 | 587篇 |
2000年 | 553篇 |
1999年 | 489篇 |
1998年 | 162篇 |
1997年 | 135篇 |
1996年 | 141篇 |
1995年 | 143篇 |
1994年 | 113篇 |
1993年 | 97篇 |
1992年 | 267篇 |
1991年 | 285篇 |
1990年 | 248篇 |
1989年 | 212篇 |
1988年 | 208篇 |
1987年 | 219篇 |
1986年 | 192篇 |
1985年 | 177篇 |
1984年 | 111篇 |
1983年 | 126篇 |
1982年 | 85篇 |
1981年 | 70篇 |
1979年 | 129篇 |
1978年 | 77篇 |
1977年 | 69篇 |
1975年 | 58篇 |
1974年 | 65篇 |
1973年 | 88篇 |
1970年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Raval RC Bilimoria FE Patel HA 《Indian journal of dermatology, venereology and leprology》1995,61(3):137-139
Fifty cases with chronic idiopathic urticaria of more than 3 months duration were selected and divided into two groups. Group 'A' was given 10 mg loratadine once daily, while group 'B' was given pheniramine maleate 25 mg, twice daily for one month. All patients were followed for one month more. 48% excellent response was observed in group 'A' while 16% excellent response was observed in group 'B'. Good response was observed in 24% of patients in group 'A', while in group 'B' 16% of patients had good response. No side effects were observed in loratadine group, while drowsiness was observed in pheniramine group. 相似文献
122.
In 21 consecutive patients, the authors analyzed changes in venous Doppler waveforms of damped or diminished cardiac pulsatility and respiratory phasicity. Each patient was suspected of having upper limb venous thrombosis, but thrombus was not visible at gray-scale ultrasonography (US) in the subclavian and brachiocephalic veins. US findings were compared with phlebographic findings. The results show that US can be used to establish the presence or absence of thrombosis in the distal portion of the brachiocephalic or subclavian veins, which are inaccessible to direct insonation. 相似文献
123.
Water-suppression MRI: role in the evaluation of osseous lesions 总被引:1,自引:0,他引:1
Wolansky LJ Rajaraman V Lum C Park K Fiorito TF Patel S Liu WC Wedmid A 《Clinical imaging》1999,23(5):319-326
The efficacy of chemical shift based water-suppression MRI in the evaluation of bone marrow lesions has not been previously reported. T1-weighted images without and with water suppression were compared in five patients with 16 lesions. There was a significant improvement in the contrast-to-noise ratio (from 4.32 to 5.95, P < 0.01) and contrast ratio (from 1.71 to 5.69, P < 0.004) with water suppression. Water suppression may be useful clinically by increasing the conspicuity of bone marrow lesions. 相似文献
124.
125.
An Unexpected Change in DXA Calibration not Detected by Routine Quality Control Checks 总被引:2,自引:0,他引:2
G. M. Blake N. G. Preston R. Patel R. J. M. Herd I. Fogelman 《Osteoporosis international》1999,9(2):115-120
Since its commercial introduction a decade ago, the technique of dual-energy X-ray absorptiometry (DXA) has been widely recognized
as a useful and sensitive method of measuring changes in bone mineral density (BMD) at selected sites in the skeleton such
as the spine and proximal femur. Because of their high precision and stable calibration, DXA scanners are frequently used
in clinical trials to evaluate new treatments for osteoporosis. Quality assurance procedures based on regular scanning of
phantoms are widely adopted in such trials, and continuity of the phantom BMD measurements is generally believed to ensure
continuity in the in-vivo calibration. We report a change in calibration of a DXA scanner that occurred during a clinical
trial where the calibration shift was different for the spine and femur sites and was not predicted or explained by the standard
quality control procedures using phantoms. However, we show that provided patients enrolled in studies are thoroughly randomized
and the statistical analysis is confined to the differences between the treated and control groups, then the effects of such
calibration shifts on conclusions regarding the efficacy of treatment are considerably smaller than the random statistical
errors.
Received: 12 February 1998 / Accepted: 20 May 1998 相似文献
126.
Feuerstein GZ Toomey JR Valocik R Koster P Patel A Blackburn MN 《Thrombosis and haemostasis》1999,82(5):1443-1445
An inhibitory anti-factor IX/IXa antibody (BC2) has been investigated as an anti-thrombotic agent in a rat venous thrombosis model. The treatment of rats post-injury with a single bolus dose of BC2 (3 mg/kg, i.v.) resulted in an approximately 4 fold reduction in venous thrombus mass (P = 0.043). This efficacy was matched by a minimal (<2.5 fold) prolongation of the aPTT and had no effect on the prothrombin time (PT). Heparin by comparison, given as a bolus followed by continuous infusion, at doses comparable in efficacy at reducing thrombus formation, prolonged the aPTT >50 fold. These results demonstrate that the anti-factor IX/IXa antibody (BC2), when compared to heparin, can effectively reduce venous thrombosis with less disruptive consequences on blood clotting. 相似文献
127.
Muntoni F Goodwin F Sewry C Cox P Cowan F Airaksinen E Patel S Ignatius J Dubowitz V 《Neuropediatrics》1999,30(5):243-248
We present the clinical and histopathological features and the diagnostic difficulties encountered in five children affected by a motor neuron disorder other than spinal muscular atrophy. Investigations performed suggested the diagnosis of ponto-cerebellar hypoplasia type 1 (PCH-1). Severe respiratory difficulty was present at birth in two of these children; hypotonia, arthrogryposis, microcephaly and nystagmus were present in all. Early and progressive bulbar involvement with swallowing difficulties and stridor was also a common feature in these infants. Severe cognitive delay was invariably present. Brain magnetic resonance imaging showed ponto-cerebellar hypoplasia in four children while striking atrophy of the cerebellar vermis and cerebellar hemispheres were present in the fifth child. Electrophysiological and pathological investigations of proximal muscles performed at presentation in all these children were not conclusive, while the post-mortem studies, or the study of distal muscles during life, showed a clear neurogenic picture. Genetic studies excluded involvement of the SMN gene, or of other genes located on chromosome 5q, confirming that ponto-cerebellar hypoplasia type 1 is a different entity from typical proximal spinal muscular atrophy. 相似文献
128.
We describe a patient with a Mason type-III fracture of the head of the radius associated with traumatic dislocation of the elbow. The radial head was intact throughout its circumference despite being completely detached from the shaft and devoid of any soft-tissue attachments. Severe comminution of the radial neck prevented reconstruction by internal fixation and precluded prosthetic replacement of the head. The head was fixed to the shaft with a tricortical iliac-crest bone graft which replaced the neck. Two years later, the patient had a stable elbow with flexion from 10 degrees to 130 degrees. Radiologically, the head of the radius appeared to be viable and the bone graft had incorporated. 相似文献
129.
Anaesthesia for LSCS in a morbidly obese patient 总被引:1,自引:0,他引:1
Patel J 《Anaesthesia and intensive care》1999,27(2):216-219
The management of a morbidly obese parturient with a body mass index of 88 is reported. She developed asthma during the pregnancy. Lumbar epidural anaesthesia was successfully used for an elective caesarean section and tubal ligation. 相似文献
130.
A novel topical clofazimine (CLO) gel formulation containing liposomally encapsulated CLO, was prepared and investigated in vitro followed by a clinical evaluation. CLO liposomes were prepared by the lipid film hydration technique. Comparative in vitro diffusion studies were conducted with plain and liposomal CLO in HPMC K4M gel base (2% and 5%) using human cadaver skin (HCS). A double blind clinical study was conducted on eight leprosy patients. The results of these studies show that the new liposomal topical gel formulation not only prolongs the drug release but also promotes drug retention by the skin. Studies further support formation of a reservoir of drug on the skin modifying therapeutic efficacy of the formulation. The new liposomal gel formulation of CLO considerably reduces the healing time of external lesions due to a significantly prolonged skin residence time compared to plain CLO gel and hence is expected to reduce the time needed for leprosy treatment. 相似文献