全文获取类型
收费全文 | 9535篇 |
免费 | 670篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 93篇 |
儿科学 | 342篇 |
妇产科学 | 146篇 |
基础医学 | 1387篇 |
口腔科学 | 141篇 |
临床医学 | 832篇 |
内科学 | 1773篇 |
皮肤病学 | 194篇 |
神经病学 | 1123篇 |
特种医学 | 339篇 |
外国民族医学 | 5篇 |
外科学 | 1452篇 |
综合类 | 65篇 |
一般理论 | 6篇 |
预防医学 | 505篇 |
眼科学 | 227篇 |
药学 | 942篇 |
中国医学 | 4篇 |
肿瘤学 | 663篇 |
出版年
2021年 | 109篇 |
2019年 | 95篇 |
2018年 | 138篇 |
2017年 | 94篇 |
2016年 | 142篇 |
2015年 | 168篇 |
2014年 | 179篇 |
2013年 | 266篇 |
2012年 | 374篇 |
2011年 | 429篇 |
2010年 | 211篇 |
2009年 | 196篇 |
2008年 | 347篇 |
2007年 | 397篇 |
2006年 | 402篇 |
2005年 | 360篇 |
2004年 | 421篇 |
2003年 | 396篇 |
2002年 | 321篇 |
2001年 | 336篇 |
2000年 | 330篇 |
1999年 | 262篇 |
1998年 | 98篇 |
1997年 | 105篇 |
1996年 | 95篇 |
1995年 | 77篇 |
1993年 | 73篇 |
1992年 | 217篇 |
1991年 | 218篇 |
1990年 | 210篇 |
1989年 | 235篇 |
1988年 | 214篇 |
1987年 | 195篇 |
1986年 | 185篇 |
1985年 | 205篇 |
1984年 | 131篇 |
1983年 | 92篇 |
1982年 | 82篇 |
1981年 | 80篇 |
1980年 | 82篇 |
1979年 | 139篇 |
1978年 | 91篇 |
1977年 | 80篇 |
1976年 | 106篇 |
1975年 | 101篇 |
1974年 | 96篇 |
1973年 | 74篇 |
1972年 | 74篇 |
1971年 | 87篇 |
1970年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
This study evaluates the microvascular reperfusion of ischemic skin flaps with and without acute hyperbaric oxygen (HBO) treatment. Thirty-two axial pattern epigastric skin flaps (3 x 6 cm) in male Wistar rats were subjected to 8 hours of global ischemia by pedicle clamp occlusion. The rats were divided into the following control and two experimental groups: Control (n = 12) with ischemia, no HBO; Group 1 (n = 11) with HBO treatment (three 1.75-hour dives, 2.5 absolute atm, 100% O2) during ischemia; and Group 2 (n = 9) with HBO treatment (two 1.75-hour dives) immediately after ischemia. Laser Doppler flows were recorded in two distal standardized flap locations at 0.5, 2, 4, and 18 hours after reperfusion in control rats and Group 1 rats and at 18 hours only in Group 2 rats, using a Med-Pacific 6000 laser Doppler unit. Mean distal flap laser Doppler flows (mV) were Control: 0.5 hours = 23.2 +/- 11.9, 2 hours = 52.8 +/- 27.3, 4 hours = 53.6 +/- 32.1, 18 hours = 40.2 +/- 36.2; Group 1: 0.5 hours = 71.8 +/- 30.9 (p less than 0.05 vs. control), 2 hours = 74.3 +/- 27.3, 4 hours = 67.4 +/- 20.6, 18 hours = 79.1 +/- 40.3 (p less than 0.05 vs. control); and Group 2: 18 hours = 90.3 +/- 47.9 (p less than 0.05 vs. control). It is concluded that acute HBO treatment of ischemic rat skin flaps improves distal microvascular perfusion as measured by laser Doppler flowmetry. This effect is observed for HBO treatment given either during or immediately after prolonged global ischemia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
22.
23.
VIM thalamic stimulation for tremor in a patient with IgM paraproteinaemic demyelinating neuropathy. 总被引:1,自引:0,他引:1
Evzen R?zicka Robert Jech Katerina Zárubová Jan Roth Dusan Urgosík 《Movement disorders》2003,18(10):1192-1195
We demonstrate the effect of deep brain stimulation of the ventral intermediate thalamic nucleus on intractable action tremor, in a 72-year-old man suffering from neuropathy associated with monoclonal gammopathy. 相似文献
24.
A case of tracheal agenesis, a rare foregut malformation, is described. This malformation is combined with a tracheo-oesophageal fistula, furthermore with rectal and anal atresia, cardiac malformations, dysplastic kidneys, wedge-shaped vertebrae, and cerebellar hypoplasia. Since a tracheo-oesophageal fistula is a possible component of the VACTERL Association [(V) vertebral defects, (A) anal atresia, (C) cardial malformations, (T) tracheo-(E)-oesophageal fistula, (R) renal or (L) limb malformations], similar cases are reviewed from the literature and their relationship to this association is discussed. 相似文献
25.
Dopamine neurons projecting to the medial prefrontal cortex possess release-modulating autoreceptors 总被引:6,自引:0,他引:6
The ability of dopamine (DA) agonists and antagonists to modulate the K+-evoked overflow of radioactivity from superfused slices of prefrontal cortex of the rat, preincubated with [3H]DA in the presence of 1 microM desipramine, was examined. Apomorphine and the putative autoreceptor-selective DA agonist EMD 23 448 inhibited the K+-evoked overflow of radioactivity, while the DA antagonist sulpiride enhanced the evoked overflow in a dose-dependent and stereoselective manner. The latter effect was partially reversed by EMD 23 448. More than 95% of the radioactivity retained by the slices chromatographed with DA, while deaminated metabolites represented the majority of both the basal efflux (84% metabolites, 4-5% DA) and evoked overflow (84% metabolites, 14% DA) of radioactivity. These findings indicate that mesoprefrontal DA neurons possess release-modulating nerve terminal autoreceptors. Previous studies have shown that these neurons lack synthesis-modulating autoreceptors. Thus, autoreceptors on prefrontal DA terminals appear to be coupled to regulation of the release but not the synthesis of DA. 相似文献
26.
I W Reimann M Jedrychowski R Schulz K H Antonin A Roth P R Bieck 《Arzneimittel-Forschung》1987,37(10):1174-1178
2-Phenylpyrazolo[4,3-c]quinolin-3(5H)-one (CGS 8216) is pharmacologically characterized as benzodiazepine antagonist with low inverse agonistic effects. Single oral doses up to 650 mg and subchronic doses up to 100 mg daily for seven days are well tolerated by young healthy volunteers. Plasma concentrations of CGS 8216 are variable, not dose-related and relatively low considering the doses administered. A high plasma concentration ratio of metabolite vs. parent compound (3:1) points to an extensive gastrointestinal first-pass metabolism. CGS 8216 influences the human electroencephalogram similar to anxiolytic and vigilance enhancing drugs in doses which do not change performance of psychometric tests. CGS 8216 antagonizes the diazepam-induced impairment of alertness. 相似文献
27.
On the Acylation of Hydroxy- and Mercaptocarboxylic Acid Esters Using the Carbodiimide/Acylation Catalyst Method Acylation of esters of hydroxycarboxylic acids can be carried out easily and in good yields by using the carbodiimide/acylation catalyst method. The reaction has also been applied to dihydroxy- and mercaptocarboxylic acid esters. The compounds formed from certain esters of hydroxycarboxylic acids are unstable to heat and decompose easily to the free carboxylic acid. No racemization is observed when using enantiomeric hydroxycarboxylic acids. Use of racemic carboxylic acids leads to diastereomers, whose 1H-NMR shifts for characteristic protons are different as expected. Five drugs are among the carboxylic acids investigated in this context. 相似文献
28.
K H Ladwig W Lehmacher R Roth G Breithardt T Budde M Borggrefe 《Zeitschrift für Kardiologie》1991,80(11):649-656
369 (63%) of 586 consecutive patients with confirmed myocardial infarction were admitted to hospital within 6 h of symptom onset. Patients' arrival to hospital followed a characteristic circadian distribution with a marked morning increase between 0600 and 1200 hours, and a corresponding decrease in the late night hours. There were no differences in the occurrence of late potentials and in ECG data between early and late arrival group. The early group (less than 5.9 h) was, however, characterized by significantly higher cardiac enzyme levels than the late group (greater than 6.0 h); they also experienced more arrhythmic events in the acute phase (16.0% vs. 9.7%; p less than 0.032). Catecholamines were significantly more often necessary (26.4% vs. 10.3%; p less than 0.0001). Six-month prognosis after AMI was markedly worse. The time between symptom onset and hospital arrival was not affected by age and risk factors. In univariate analysis, pain history and recurrent infarction also had no influence on delay of admission to hospital. The time interval was, however, significantly shorter when the acute event occurred during the night (18.4% vs. 8.3%; p less than 0.0001). Absence of prodromi in the prehospital phase (18.5% vs. 12.0%; p less than 0.04) and a higher socio-economic level (68.3% vs. 61.0%; p less than 0.077) also shortened the admission time, whereas a hyperactive behavioral pattern prolonged the delay time (21.1% vs. 28.9%; p less than 0.05). 相似文献
29.
Computer-assisted design and manufacturing technology has been used to create solid models of five unusually complex, multidirectional malunions of distal radius fractures. Preoperative planning was dramatically enhanced by the ability to perform the surgical procedure on these models, with a model of the uninjured limb used for comparison. All five patients had significant malunions, with malrotation in the horizontal plane in five and an impacted articular fragment in two. A satisfactory outcome was achieved in each case. 相似文献
30.
Pernes JM; Vitoux JF; Brenoit P; Raynaud A; Parola JL; Roth JP; Angel CY; Fiessinger JN; Roncato M; Gaux JC 《Radiology》1986,158(2):481-485
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs. 相似文献