全文获取类型
收费全文 | 1983495篇 |
免费 | 145698篇 |
国内免费 | 3663篇 |
专业分类
耳鼻咽喉 | 26900篇 |
儿科学 | 64107篇 |
妇产科学 | 56130篇 |
基础医学 | 289867篇 |
口腔科学 | 55467篇 |
临床医学 | 178280篇 |
内科学 | 390609篇 |
皮肤病学 | 42608篇 |
神经病学 | 158808篇 |
特种医学 | 76361篇 |
外国民族医学 | 584篇 |
外科学 | 293722篇 |
综合类 | 41890篇 |
现状与发展 | 3篇 |
一般理论 | 788篇 |
预防医学 | 156998篇 |
眼科学 | 45209篇 |
药学 | 144045篇 |
6篇 | |
中国医学 | 3568篇 |
肿瘤学 | 106906篇 |
出版年
2018年 | 20570篇 |
2016年 | 17345篇 |
2015年 | 19929篇 |
2014年 | 27874篇 |
2013年 | 42873篇 |
2012年 | 57954篇 |
2011年 | 61765篇 |
2010年 | 36503篇 |
2009年 | 34821篇 |
2008年 | 58563篇 |
2007年 | 62393篇 |
2006年 | 62174篇 |
2005年 | 61061篇 |
2004年 | 58649篇 |
2003年 | 56391篇 |
2002年 | 54946篇 |
2001年 | 87561篇 |
2000年 | 89573篇 |
1999年 | 76012篇 |
1998年 | 21389篇 |
1997年 | 19480篇 |
1996年 | 19856篇 |
1995年 | 18576篇 |
1994年 | 17516篇 |
1993年 | 16448篇 |
1992年 | 60316篇 |
1991年 | 58814篇 |
1990年 | 57414篇 |
1989年 | 55360篇 |
1988年 | 51450篇 |
1987年 | 50396篇 |
1986年 | 48253篇 |
1985年 | 45760篇 |
1984年 | 34630篇 |
1983年 | 29897篇 |
1982年 | 17947篇 |
1981年 | 16089篇 |
1979年 | 32885篇 |
1978年 | 23705篇 |
1977年 | 19956篇 |
1976年 | 18586篇 |
1975年 | 20276篇 |
1974年 | 24465篇 |
1973年 | 23837篇 |
1972年 | 22539篇 |
1971年 | 20926篇 |
1970年 | 19918篇 |
1969年 | 18800篇 |
1968年 | 17677篇 |
1967年 | 16010篇 |
排序方式: 共有10000条查询结果,搜索用时 41 毫秒
991.
Dorsal dislocation of the ulnar styloid and extensor carpi ulnaris tendon into the distal radioulnar joint: the empty sulcus sign 总被引:1,自引:0,他引:1
Two cases of distal radioulnar joint (DRUJ) disruption and diastasis secondary to distal radial fractures were associated with displacement of the ulnar styloid and extensor carpi ulnaris (ECU) into the DRUJ. Both cases had a palpable empty ECU tendon sulcus. In one case surgical exploration revealed that the ulnar styloid, triangular fibrocartilage, and extensor carpi ulnaris tendon had dislocated into the DRUJ as a unit. The end result was good. In the second case lack of recognition and reduction of the ECU tendon and ulnar styloid led to persistent subluxation and diastasis. The end result was poor. Early recognition of the dislocation of the ulnar and ECU into the DRUJ and their significance may avoid poor results. 相似文献
992.
G Fran?ois C Mycinski L F Garnier B Charbonnier M Marchand L Guillou M Brochier 《Archives des maladies du coeur et des vaisseaux》1987,80(3):367-370
The authors report a case of massive haemolytic anaemia with acute mitral valve regurgitation and left cardiac failure, which occurred one year after surgical reconstruction of the mitral valve for rupture of smaller leaflet chordae. Anaemia, mitral regurgitation and cardiac failure disappeared after mitral valve replacement, using a Carpentier Edwards No. 29 valve. Haemolytic anaemia following mitral valve reconstruction is exceptional. It seems to be due to the suture material lying in a turbulent regurgitation stream when mitral incompetence develops again. 相似文献
993.
994.
ANDREW A. AMOSCATO GEORGE F. BABCOCK R. MICHAEL SRAMKOSKI BARBARA A. HYND J. WESLEY ALEXANDER 《Chemical biology & drug design》1987,29(2):177-186
This study reports on the synthesis of two fluorescent analogues of thymopentin (TP-5; Arg-Lys-Asp-Val-Tyr). A fluorescein isothiocyanate labeled analogue (FITC-TP-5) and a stilbene isothiocyanate labeled analogue (SITS-TP-5) were extensively purified by ion-exchange and gel filtration chromatography. Characterization of the coupling site through amino acid analysis, dansylation and N-terminal cleavage of the fluorescent amino acid yielded results which indicated that both were mono-labeled analogues derivatized at the N-terminal. These analogues were shown to be TP-5-like in nature by their ability to induce the expression of the Thy 1.2 surface marker on nude mouse prothymocytes in both in vivo and in vitro assays. In addition, these analogues were able to inhibit the specific binding of radiolabeled TP-5 to human lymphocytes. Initial studies describing the interaction of FITC-TP-5 with human lymphocytes are shown. 相似文献
995.
Comparison of PET, MRI, and CT with pathology in a proven case of Alzheimer's disease 总被引:1,自引:0,他引:1
Positron emission tomography (PET) with fluorodeoxyglucose (FDG), magnetic resonance imaging (MRI), and CT were carried out in a patient with Alzheimer's disease 16 months before he died. At autopsy, the gross appearance of the brain correlated with MRI and CT, which showed some regional atrophy. These were much less revealing than PET, which correlated with microscopic findings of neuronal loss and proliferation of glia. In areas of moderately impaired local cerebral metabolic rate of glucose, as revealed by reduced FDG uptake, there was some gliosis, primarily around the numerous senile plaques. In areas of severe metabolic impairment, there was a profound loss of neurons, extensive gliosis, and a diminished appearance of plaques. PET-FDG is a better measure of the severity of Alzheimer's disease than MRI or CT, because it reflects the degree of neuronal pathology. 相似文献
996.
A retrospective study was done in 316 patients with primary cervical adenocarcinoma treated at the Research Institute for Clinical and Experimental Oncology in Brno over a period of 40 years (1939-1978). The treatment results were compared to those in 2571 patients with epidermoid carcinomas of the uterine cervix treated at the Institute over the same period. The 5-year survival rate was significantly lower in adenocarcinoma patients (in Stage I patients, 77.8% vs. 84.5%, and, in the whole group, 60.8% vs. 70.3%). The assessment of the treatment results of this study has clearly showed that in cervical adenocarcinomas, surgery combined with radiotherapy was much more effective than radical radiotherapy alone (77.4% vs. 64.7%). In contrast to this, in epidermoid carcinomas the treatment results were better after radical radiotherapy (86.5% vs. 81.3%). Thus, in the prognosis of cervical adenocarcinomas the mass of the tumor, the size of the uterus, as well as the grading play a role. That means that primary cervical adenocarcinomas at early stages can be successfully treated by a combination of radical surgery and radiotherapy, while radiotherapy of advanced stages of this tumor is less successful. 相似文献
997.
Differential diagnosis of poisoning by North American mushrooms, with particular emphasis on Amanita phalloides-like intoxication 总被引:2,自引:0,他引:2
It is possible to determine the management and prognosis of mushroom poisoning from the history and initial symptoms with a high degree of confidence. The most important intoxications are those involving Amanita phalloides or other potentially fatal amatoxin-containing mushrooms, which have a latent period of ten to 12 hours before the patient becomes symptomatic. Because aggressive gastroenteric decontamination can reduce the extent of hepatic damage, it is important to attempt to determine during this asymptomatic period whether amatoxin exposure has occurred. Various laboratory methods that might be useful are reviewed. 相似文献
998.
G H Ballantyne M J Zdon D E Schafer G R Fratesi J R Roberts M Tyshkov I M Modlin 《Annals of surgery》1986,204(5):559-565
The cellular mechanisms by which pepsinogen (PNG) secretion is controlled are not understood. The aim of this study was to explore whether modulation of PNG secretion is mediated by cAMP or calcium-calmodulin (C-C). PNG secretion in isolated rabbit gastric fundic glands (IGG) was tested, using agents believed to act via cAMP or C-C. IGG were stimulated for 30 minutes with histamine (H) 10(-5) M, isoproterenol (I) 10(-5) M, carbachol (C) 10(-5) M, cholecystokinin-octapeptide (CCK-8) 10(-7) M, forskolin (F) 10(-5) M, 8 bromo-cAMP (8B) 10(-3) M, and A23187 (A) 10(-6) M. PNG levels were determined by spectrophotometric assay of hemoglobin digestion products. PNG amounts secreted were (mean per cent above basal levels of total IGG PNG units +/- SEM): H, -0.02 +/- 0.30%; I, 3.5 +/- 0.9%; C, 5.1 +/- 2.2%; CCK-8, 5.3 +/- 1.5%; F, 10.6 +/- 3.8%; 8B, 13.8 +/- 4.5%; A, 2.1 +/- 1.1%. All secretagogues except H stimulated PNG release significantly above basal levels (p less than 0.05). A primary histaminergic mechanism for pepsinogen secretion is unlikely. Since two other adenylate cyclase activators, isoproterenol and forskolin and the 3':5'-cyclic adenosine monophosphate analog 8-bromo cAMP stimulated pepsinogen secretion, cAMP-dependence is probable. Since carbachol, CCK-8, and A23187, which are believed to act via calcium-calmodulin, also stimulated pepsinogen secretion, this system, too, presumably plays a substantial role. Thus the data support a dual 3':5'-cyclic adenosine monophosphate/calcium-calmodulin modulation of pepsinogen secretion. 相似文献
999.
1000.
Neutropenic enterocolitis in adults with acute leukemia 总被引:2,自引:0,他引:2
Neutropenic enterocolitis has been previously described only by case reports and literature reviews. Of 499 adults with acute leukemia seen over a 23-year period (1962 to 1985), 13 cases (2.6%) of neutropenic enterocolitis have been reported. Eleven of these 13 patients were profoundly neutropenic (mean white blood cell count, 472/cu mm) and developed abdominal symptoms during either initial induction or relapse of acute leukemia. Histologic confirmation was available in ten cases, five cases after surgical resection and five cases at autopsy after nonoperative management. Three patients with isolated ileocecal inflammation without infarction at the time of surgery were successfully managed without resection. Five patients treated with surgery died four to 64 weeks postoperatively (mean survival, 21.6 weeks) of nonsurgical complications of leukemia. Three patients were still alive, one patient 42 months after right hemicolectomy and two patients five months after exploration only. All five patients managed medically died an average of 1.4 days (range, zero to four days) after the onset of abdominal pain. Survival in patients with acute leukemia who develop neutropenic enterocolitis is determined by early recognition and appropriate surgical exploration that can be expected to yield an acceptable operative mortality. 相似文献