全文获取类型
收费全文 | 50295篇 |
免费 | 3511篇 |
国内免费 | 267篇 |
专业分类
耳鼻咽喉 | 517篇 |
儿科学 | 1109篇 |
妇产科学 | 932篇 |
基础医学 | 7335篇 |
口腔科学 | 646篇 |
临床医学 | 4607篇 |
内科学 | 11540篇 |
皮肤病学 | 778篇 |
神经病学 | 5272篇 |
特种医学 | 1784篇 |
外国民族医学 | 4篇 |
外科学 | 8876篇 |
综合类 | 297篇 |
一般理论 | 15篇 |
预防医学 | 2884篇 |
眼科学 | 703篇 |
药学 | 3342篇 |
中国医学 | 165篇 |
肿瘤学 | 3267篇 |
出版年
2023年 | 210篇 |
2022年 | 428篇 |
2021年 | 880篇 |
2020年 | 598篇 |
2019年 | 1029篇 |
2018年 | 1160篇 |
2017年 | 897篇 |
2016年 | 991篇 |
2015年 | 1211篇 |
2014年 | 1631篇 |
2013年 | 2222篇 |
2012年 | 3370篇 |
2011年 | 3594篇 |
2010年 | 2205篇 |
2009年 | 2023篇 |
2008年 | 3230篇 |
2007年 | 3343篇 |
2006年 | 3124篇 |
2005年 | 3295篇 |
2004年 | 3011篇 |
2003年 | 3050篇 |
2002年 | 2973篇 |
2001年 | 637篇 |
2000年 | 546篇 |
1999年 | 656篇 |
1998年 | 697篇 |
1997年 | 642篇 |
1996年 | 480篇 |
1995年 | 484篇 |
1994年 | 383篇 |
1993年 | 394篇 |
1992年 | 396篇 |
1991年 | 341篇 |
1990年 | 301篇 |
1989年 | 294篇 |
1988年 | 251篇 |
1987年 | 248篇 |
1986年 | 284篇 |
1985年 | 226篇 |
1984年 | 231篇 |
1983年 | 227篇 |
1982年 | 220篇 |
1981年 | 187篇 |
1980年 | 186篇 |
1979年 | 157篇 |
1978年 | 107篇 |
1977年 | 116篇 |
1975年 | 99篇 |
1974年 | 86篇 |
1973年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Gérald Vanzetto Marc Janier Daniel Fagret Luc Cinotti Xavier André-Fouet Michel Comet Jacques Machecourt 《European journal of nuclear medicine and molecular imaging》1997,24(2):170-178
The best test presently available to ascertain residual viability within an infarct-related area involves the use of fluorine-18
fluorodeoxyglucose (FDG) to detect the persistence of some cellular metabolism. Rest reinjection of thallium-201 is a less
accurate alternative but is easy to perform. Iodinated fatty acids, which are used with standard gamma cameras, are proposed
as markers of cellular metabolism. This study was performed to assess the value of 16-iodo-3-methyl-hexadecanoic acid (MIHA)
as a marker of the residual cellular metabolism by comparison with FDG in patients with a recent myocardial infarction, and
to evaluate its contribution compared with the201Tl stress-redistribution-reinjection technique. Stress-redistribution-reinjection201T1 imaging, rest MIHA imaging and glucoseloaded FDG imaging were performed in 22 patients with recent myocardial infarction.
Out of the 628 myocardial segments obtained from the left ventricular analysis, 400 were hypoperfused (relative uptake <0.75
of maximum uptake on stress201T1 imaging), 177 of which were severely hypoperfused (relative uptake <0.50). Receiver operating characteristic (ROC) curves
for predicting metabolic myocardial viability with FDG were derived from the results in respect of (a)201T1 activity during exercise, redistribution and reinjection and (b) MIHA up-take, using the two FDG thresholds most commonly
considered to define metabolic viability (0.50 and 0.60). Analysis of the 400 hypoperfused segments demonstrated that201T1 reinjection was the most accurate test in predicting the presence of myocardial viability (area under the ROI curves=0.85
and 0.86 at the 0.50 and 0.60 FDG thresholds, respectively;P<0.05 vs other tests). The global predictive values of MIHA and201T1 reinjection were, respectively, 0.87 and 0.89 at the 0.50 FDG threshold (NS), and 0.82 and 0.87 at the 0.60 FDG threshold
(NS). When only the 177 severely hypoperfused segments were considered,201T1 reinjection remained the most accurate test (accuracy 0.84 at the 0.50 FDG threshold and 0.82 at the 0.60 FDG threshold),
while the accuracy of MIHA decreased significantly (0.78 at the 0.50 FDG threshold and 0.73 at the 0.60 FDG threshold,P<0.05 vs201T1 reinjection). In all circumstances, MIHA was less specific than201T1 reinjection for the detection of metabolic viability. In conclusion, in patients with recent myocardial infarction, MIHA
accurately detects the persistence of metabolic viability, but is not superior to201T1. 相似文献
92.
Marie-Francoise Dresse Michele David Heather Hume Herve Blanchard Pierre Russo Nicolas Van Doesberg Georges E. Rivard 《Pediatric hematology and oncology》1991,8(4):329-334
The Kasabach-Merritt syndrome is characterized by thrombocytopenia and localized coagulopathy associated with a hemangioma. Most techniques applied to eradicate the tumor or accelerate its involution (surgery, radiation therapy, embolization) are invasive and require transfusion of large amounts of blood products. In some cases, medical treatment is the only alternative. Efficacy of steroids and antifibronolytic agents has already been described, but even this approach is associated with the administration of blood products. We report two cases of infants with Kasabach-Merritt syndrome associated with cardiac and hepatic hemangiomas. At admission, both had signs of cardiac failure. They were successfully treated with prednisone and epsilon-aminocaproic acid (EACA). Blood products were not required once the diagnosis was made. These observations have important implications for the management of patients with Kasabach-Merritt syndrome because they show that even in severe cases blood transfusions can be avoided by the use of prednisone and EACA. 相似文献
93.
Pierre Pradat 《Genetic epidemiology》1994,11(2):131-140
During the period 1981–1986, 1605 infants presenting a major congenital heart defect (CHD) were identified in Sweden. Using the personal identification numbers of the mothers, 1507 of them could be linked to the Medical Birth Registry and two controls were selected for each infant. For this total of 4521 infants, 2686 postoccurrence sibs born during the period 1981–1989 were identified from the Medical Birth Registry. The tendency to have one or more sibs was higher among cases than among controls and was correlated to the life status of the proband. This tendency did not vary according to the type of CHD when controlling for life status. The prevalence at birth of CHD was almost four times higher among sibs of CHD infants than among sibs of normal infants. The tendency to have a sib with an extracardiac malformation did not differ between CHD probands and normal probands. The importance of only including births occurring after the proband when evaluating recurrence risks is stressed. © 1994 Wiley-Liss, Inc. 相似文献
94.
Brain glucose utilisation in acquired childhood aphasia associated with a sylvian arachnoid cyst: recovery after shunting as demonstrated by PET. 总被引:4,自引:0,他引:4 下载免费PDF全文
A G De Volder C Michel C Thauvoy G Willems G Ferrière 《Journal of neurology, neurosurgery, and psychiatry》1994,57(3):296-300
Regional brain glucose utilisation was investigated with PET and fluorodeoxyglucose (FDG) in a case of epileptic aphasia (Landau-Kleffner syndrome) associated with a left sylvian arachnoid cyst. CT and MRI had failed to disclose any mass effect of the cyst on surrounding brain structures. Sequential metabolic measurements showed a comparable pronounced hypometabolism in cortical regions around the cyst, involving speech areas, and suggested mild but chronic compression of the developing brain. After placement of a cyst-peritoneal shunt system, significant metabolic improvement occurred in all cortical regions, especially the inferior frontal gyrus and the perisylvian area, with predominant residual deficit in the left superior temporal gyrus. These findings were correlated with a pronounced increase in word fluency and slower progress in verbal auditory comprehension. This report suggests that PET is able to evaluate the functional disturbances associated with expanding arachnoid cysts, and to follow the neurological improvement after drainage. 相似文献
95.
Farsin Hamzei Michel Rijntjes Joystone Gbadamosi Kornelius Fuchs Cornelius Weiller Alexander Münchau 《Movement disorders》2003,18(8):959-961
We report on a woman with a an 8-year history of multiple system atrophy with predominance of parkinsonism who developed jaw-locking oromandibular dystonia within hours after insertion of ill-fitting dentures. Dystonia spread rapidly to involve other facial muscles and the larynx causing stridor with respiratory failure necessitating crush intubation. 相似文献
96.
Pierre Beaulieu 《Journal canadien d'anesthésie》2006,53(8):769-775
PURPOSE: Cannabinoids have been shown to have analgesic properties in animal studies, but a potential role for these drugs in acute pain management has not been established. It was hypothesized that nabilone, an oral cannabinoid synthetic tetrahydrocannabinol analogue, decreases morphine consumption, pain scores, nausea and vomiting following major surgery. METHODS: A double-blind, randomized, placebo-controlled, parallel-group pilot trial compared the effects of two different doses, 1 mg (n = 11) and 2 mg (n = 9) of nabilone, ketoprofen 50 mg (n = 11) or placebo (n = 10), given at eight-hour intervals for 24 hr. Outcomes included morphine consumption, pain scores and emesis after major surgery. Secondary outcomes included patient tolerability of the study medication. RESULTS: Forty-one patients (mean age 52 +/- 2 yr) undergoing gynecologic (46%), orthopedic (44%), or other (10%) surgery were recruited. Cumulative 24-hr morphine consumption was not different between the four groups, but pain scores at rest and on movement were significantly higher in the 2 mg nabilone group compared to the other groups. There were no significant differences between groups with respect to episodes of nausea and vomiting, quality of sleep, sedation, euphoria, pruritus, or the number and severity of adverse events. No serious adverse event was recorded. CONCLUSIONS: Contrary to the main hypothesis, high dose nabilone in the presence of morphine patient controlled analgesia is associated with an increase in pain scores in patients undergoing major surgery. 相似文献
97.
Renaud de Beaurepaire Michael Lukasiewicz Patrick Beauverie Sophie Castra Odile Dagorne Renaud Espaze Bruno Falissard Patrick Giroult Michle Houery Georges Mahuzier Isabelle Matheron Philippe Niel Pierre Padovani Nicole Poisson Jean-Paul Richier Jrme Rocher Odile Ruetsh Didier Touzeau Andr Visinoni Robert Molimard 《European psychiatry》2007,22(8):540-548
BACKGROUND: Asking psychiatric in-patients about their drug consumption is unlikely to yield reliable results, particularly where alcohol and illicit drug use is involved. The main aim of this study was to compare spontaneous self-reports of drug use in hospitalized psychiatric patients to biological measures of same. A secondary aim was to determine which personal factors were associated with the use of tobacco, alcohol, and illicit drugs as indicated by these biological measures. METHODS: The consumption of substances was investigated using biological measures (urine cotinine, cannabis, opiates, cocaine, amphetamines and barbiturates; blood carbohydrate-deficient transferrin [CDT] and gamma-glutamyl transferase [GGT]) in 486 consecutively admitted psychiatric patients, one day following their hospitalization. Patients' self-reports of alcohol, tobacco and illicit drugs consumption were recorded. Socio-professional and familial data were also recorded. RESULTS: The results show a low correlation between biological measures and self-reported consumption of alcohol and illicit drugs. Fifty-two percent of the patients under-reported their consumption of illicit drugs (kappa=.47). Patients with schizophrenia and personality disorders were more likely to disclose their illicit drug consumption relative to patients suffering from mood disorders and alcohol dependence. Fifty-six percent of patients underreported alcohol use, as evaluated by CDT (kappa=.2), and 37% underreported when using the CDT+GGT measure as an indicator. Smoking appeared to be reported adequately. In the study we observed a strong negative correlation between cannabis use and age, a strong correlation between tobacco and cannabis use, and correlations between tobacco, cannabis and alcohol consumption. CONCLUSION: This study is the first to compare self-reports and biological measures of alcohol, tobacco and illicit drug uses in a large sample of inpatients suffering from various categories of psychiatric illnesses, allowing for cross-diagnosis comparisons. 相似文献
98.
99.
B. J. Morris F. Pinet J.-B. Michel F. Soubrier P. Corvol 《Clinical and experimental pharmacology & physiology》1987,14(3):227-231
1. A pulmonary chemodectoma/glomangiosarcoma that had metastasized from the thigh was studied after removal from a 22 year old Algerian patient with hypertension, high plasma prorenin and signs of secondary aldosteronism. 2. Renin and renin mRNA were localized in sections of the tumour tissue using monoclonal anti-human renin antibody and human renin cDNA probe, respectively. 3. The cells grew prolifically in culture, but, even though their renin content was similar to that of transfected human juxtaglomerular cell tumour cells (approximately 1 pg/microgram DNA), their rate of secretion of renin was much lower (0.05-0.15 cf. 0.5-1.5 pg/h per microgram DNA). 4. Forskolin (10 mumol/l for 24 h) increased secretion of renin from 1.9 +/- 0.36 to 4.1 +/- 0.64 pg/ml per h of culture (P less than 0.001, n = 11), consistent with cAMP being a second messenger in the secretory mechanism. 5. The cells should provide valuable information about intracellular mechanisms for the regulation of renin synthesis and secretion. 相似文献
100.
Michel Broyer Geneviève Guest Marie-France Gagnadoux Daniel Beurton 《Pediatric nephrology (Berlin, Germany)》1987,1(1):16-21
The files of 334 consecutive cadaver kidney (CK) and of 27 living related (LR) transplantations (T) in children and adolescents performed from 1973 to 1984 have been reviewed. Following cadaver transplantation, 52 patients (15%) never had hypertension (HT), 41 patients (12%) had only initial HT up to 6 months after transplantation and 18 other patients (5%) exhibited transient HT episodes while on high-dose steroid therapy. Finally, 209 patients (62%) had HT for periods longer than 6 months and 16 patients (5%) until death or graft failure within the first 3 months. Chronic graft rejection was the major cause of HT, but other factors either isolated or in association were also present. Renal artery stenosis (RAS) was diagnosed in 43 cases (13%) 2–17 months post-transplantation; 10 of these were operated upon (5 successfully) and 9 underwent transluminal angioplasty with a single success. Nine cases of RAS resolved spontaneously. HT was attributed to the host kidney in 10 cases (3%) and to recurrence of primary renal disease in 9 (3%). HT observed after CKT was sometimes severe and difficult to control. Acute complications from HT were recorded in 35 cases, with 6 deaths and 2 severe neurological sequelae. Among 25 LRT, 11 cases (40%) had no HT 13 (48%) had HT for longer than 6 months. In this group, no case of RAS was observed and only one complication (without sequelae) was noted. In conclusion, HT is a frequent and sometimes severe complication post-transplantation in children and adolescents. 相似文献