全文获取类型
收费全文 | 7856篇 |
免费 | 460篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 211篇 |
妇产科学 | 159篇 |
基础医学 | 1034篇 |
口腔科学 | 564篇 |
临床医学 | 705篇 |
内科学 | 1621篇 |
皮肤病学 | 206篇 |
神经病学 | 554篇 |
特种医学 | 168篇 |
外科学 | 1059篇 |
综合类 | 48篇 |
一般理论 | 1篇 |
预防医学 | 665篇 |
眼科学 | 243篇 |
药学 | 657篇 |
中国医学 | 54篇 |
肿瘤学 | 307篇 |
出版年
2023年 | 75篇 |
2022年 | 181篇 |
2021年 | 300篇 |
2020年 | 178篇 |
2019年 | 228篇 |
2018年 | 281篇 |
2017年 | 166篇 |
2016年 | 223篇 |
2015年 | 266篇 |
2014年 | 362篇 |
2013年 | 399篇 |
2012年 | 556篇 |
2011年 | 674篇 |
2010年 | 317篇 |
2009年 | 247篇 |
2008年 | 404篇 |
2007年 | 464篇 |
2006年 | 391篇 |
2005年 | 391篇 |
2004年 | 305篇 |
2003年 | 239篇 |
2002年 | 219篇 |
2001年 | 160篇 |
2000年 | 140篇 |
1999年 | 134篇 |
1998年 | 54篇 |
1997年 | 36篇 |
1996年 | 43篇 |
1995年 | 36篇 |
1994年 | 25篇 |
1993年 | 20篇 |
1992年 | 73篇 |
1991年 | 87篇 |
1990年 | 45篇 |
1989年 | 65篇 |
1988年 | 53篇 |
1987年 | 40篇 |
1986年 | 42篇 |
1985年 | 41篇 |
1984年 | 37篇 |
1983年 | 23篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 33篇 |
1979年 | 34篇 |
1978年 | 27篇 |
1977年 | 32篇 |
1976年 | 17篇 |
1975年 | 21篇 |
1974年 | 25篇 |
排序方式: 共有8350条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
Cordeiro R Peñaloza ER Cardoso CF Cortez DB Kakinami E Souza JJ Souza MT Fernandes RA Guercia RF Adoni T 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1999,15(4):719-728
The aim of this paper was to evaluate the accuracy of data on death certificates for occupation and main cause of death. Measure of agreement was assessed comparing data from death certificates with those from both medical records and next-of-kin interviews, analyzing information for 552 residents of Botucatu, Southeast Brazil, who died in 1997. Kappa coefficients of 0.31 (95% C.I. 0. 29-0.34) and 0.76 (95% C.I. 0.75-0.76) were obtained for data on occupation and main cause of death, coded by a Brazilian two-digit classification and the three-digit ICD-10 classification, respectively. One can conclude that, although quality of the main cause of death is acceptable for pilot studies, data on occupation taken only from death certificates is not accurate enough to be used in epidemiological research. 相似文献
65.
A comparison of two techniques for cervical plexus blockade: evaluation of efficacy and systemic toxicity 总被引:6,自引:0,他引:6
Merle JC Mazoit JX Desgranges P Abhay K Rezaiguia S Dhonneur G Duvaldestin P 《Anesthesia and analgesia》1999,89(6):1366-1370
We compared two techniques of cervical plexus blockade (CPB) for carotid endarterectomy. Cervical plexus nerve block was performed with a combination of bupivacaine and lidocaine, with injections at the C2-C3, C3-C4, and C4-C5 transverse processes in 11 patients (classical CPB) or with a single injection after localization of the cervical plexus with a nerve stimulator in 12 patients (interscalene CPB). Pain scores were obtained during block placement and at predetermined phases of the operation. Arterial blood was sampled before and 3, 5, 8, 10, 15, 25, 40, and 60 min after CPB for measurement of bupivacaine and lidocaine concentrations. Interscalene CPB was less painful than classical CPB. The techniques appeared equally effective. Patients in both groups required equivalent supplementation with IV fentanyl and additional local infiltration with lidocaine during the most painful stages of surgery. The maximal concentration of bupivacaine was lower in interscalene CPB compared with classical CPB (1.0 microg/mL versus 1.5 microg/mL, P < 0.01). The time required to reach the maximal concentration of bupivacaine was 15 (10-40) min in interscalene CPB and 10 (5-17) min in classical CPB (P < 0.05). Lidocaine maximal concentration was similar in both groups, however the time required to reach the maximal concentration was longer (P < 0.05) in interscalene CPB (15 [10-60] min) than in classical CPB (10 [8-20] min). We conclude that the interscalene CPB is as effective as the classical CPB as a regional technique for carotid endarterectomy and may be associated with a lower systemic absorption of bupivacaine. IMPLICATIONS: Cervical plexus blockade for carotid endarterectomy can be effectively performed with a single injection after localization of the cervical plexus with a nerve stimulator. This technique is simple and was associated with less systemic absorption of local anesthetic than the multiple-injection technique. 相似文献
66.
Self-expanding endovascular stent-graft implant for treatment of descending aortic diseases 总被引:1,自引:0,他引:1
Stolf NA Pêgo Fernandes PM Souza LR Moitinho R Arteaga E Jatene AD 《Journal of cardiac surgery》1999,14(1):9-15
A bstract Background: Aneurysms and dissections involving the descending thoracic aorta and the distal portion of the aortic arch are difficult to resolve surgically. The introduction of endovascular self-expanding stent-grafts has simplified the operation. Given the complications associated with their peripheral placement, we explored the feasibility of surgical insertion. Methods: Thirteen patients underwent surgical insertion of a stent-graft into the aortic arch via longitudinal aortotomy. Six patients had aneurysms (ruptured in two, and seven dissections (acute in two, ruptured in one). Five patients also underwent associated procedures including aortic valve replacement (one), ascending aorta replacement (two), arch replacement (one), and coronary artery bypass (one). Results: There was one intraoperative death due to ascending aortic dissection, and two hospital deaths due to multiple complications. Of ten patients discharged, one died 3 months postoperatively. The remaining survivors are well, and imaging studies confirmed adequate correction of the aortic disease. Conclusions: The use of this technique simplifies the operation and treatment of particular cases of aortic disease. The observed morbidity and mortality are due to factors independent of the technique. 相似文献
67.
Grandbastien B Gower-Rousseau C Merle V Dupas JL Yzet T Lerebours E Marti R Laine I Cortot A Salomez JL 《Revue d'épidémiologie et de santé publique》1999,47(1):45-53
BACKGROUND: The period of time required for the diagnosis of a chronic illness depends on initial clinical symptoms and their perception by the patient and the physicians. The aim of this study was to describe the procedures of diagnosis of incident cases of Inflammatory Bowel Disease (IBD). METHODS: Patients reported by the Registry of inflammatory bowel disease of northern France (EPIMAD) in 1994 were included. Standardized questionnaires describing clinical history, patient behavior, medical consultations and examinations were collected by an interviewer practitioner from three sources: patients, general practitioners (GP) and gastroenterologists (GE). Patients were divided in 2 groups according to the time between symptom onset and diagnosis: more than 9 months or less than 9 months (D > 9 and D < or = 9). RESULTS: 258 patients were included: 144 Crohn's disease (CD) (56%), 106 ulcerative colitis (UC) (41%) and 8 chronic unclassifiable colitis (CUC). Median time between symptom onset and diagnosis was 3 months, 196 (76%) patients belonged to the group D < or = 9 and 62 (24%) to the group D > 9. There was no difference between the 2 groups for initial clinical symptoms. The delay between symptom onset and the consultation to the GP and the GE was longer in the group D > 9: respectively 1 month vs 0 and 7.6 vs 2. Thirty-five percent of patients in the group D > 9 had consulted more than one GP vs 14% (p < 0.05). Diagnosis management by the GE was the same in both groups. Patients of group D < or = 9 had more often perceived their symptoms as serious (p < 0.05). CONCLUSIONS: Delay to diagnosis in a quarter of patients with IBD was more than 9 months. This later diagnosis was not due to patient management by the GE but rather to a longer delay to consulting the GP and between GP and GE referral. Patient interpretation of the symptoms could also explain the variability of this delay. 相似文献
68.
Oliveira DA Fernandes AM De Conti R Rodríguez JA Haun M Souza-Brito AR De Castro SL Durán N 《Die Pharmazie》1999,54(11):847-850
The trypanocidal activities of cis-3-(4'-bromo[1,1'-biphenyl]-4-yl)- 3-(phenyl)-N,N-dimethyl-2-propen-1-amine (Vb) and cis-3-(4'-bromo[1,1'-biphenyl]-4-yl)-3-(4-bromophenyl)-N,N-dimethyl-2- propen-1-anine (Vg) appeared 6.3 and 3.5 fold more active than the trans-isomers, respectively. Multi-endpoints for toxicity were also applied. Neutral red uptake (NRU), tetrazolium salt reduction (MTT), DNA content on V79 fibroblast cell culture and acute toxicity von E. coli were measured. The IC50 through DNA contents was lower for the cis-isomers in both series of compounds 5b: 7.8 microM and 5g: 5.2 microM). NRU values for derivative 5b in isomeric mixture shows the same value as the isolated isomers however, in the case of 5g a more significant toxicity of the cis-isomer was found. MTT values show that 5g is more toxic than 5b. In both cases, the acute toxicity of the trans-isomers was higher than that of the cis-isomers. 相似文献
69.
In November, 1993,M.G., a 6 year and 11 month-old girl, was admitted at Hospital Infantil Joana de Gusm?o--Florianópolis, SC, Brazil--with post-parotitis myocarditis and congestive heart failure. Three days after admission it was evidenced, on an echocardiogram, a thrombus in the left ventricle apex which, despite of correct treatment, embolized to iliac and small mesenteric arteries. Epidemic parotitis (mumps) is very common, being endemic around the world. Complications are rare and myocarditis, one of them, is more common than diagnosed because of its poor and benign manifestations, generally transient abnormalities of cardiac rhythm and conduction. This case was astonishing because of its rare subsequent event, that is, the formation of a ventricular mural thrombus during an acute myocarditis. 相似文献
70.
Harrison-Read PE Tyrer P Lawson C Lack S Fernandes C File SE 《Journal of psychopharmacology (Oxford, England)》1996,10(2):89-97
Ten long-term users of benzodiazepines (average daily dose, 20 mg of diazepam or equivalent) who had experienced problems in withdrawing from the drugs were given an i.v. challenge with either the benzodiazepine antagonist flumazenil (1 mg injected over 30 s) or placebo (vehicle solution) in a randomized double-blind design. There were no 'pseudo withdrawal' responses to either single-blind or double-blind placebo injections, whereas flumazenil produced dramatic panic reactions in all four subjects tested, followed by characteristic benzodiazepine withdrawal symptoms. There were also small but significant rises in pulse rate and blood pressure, but no change in serum cortisol. Flumazenil-induced panic could not be entirely accounted for by a past or present diagnosis of panic disorder, and did not seem to be related to previous withdrawal problems, present benzodiazepine dosage, or to the severity of withdrawal symptoms precipitated by flumazenil in the same challenge test. Attempts to reduce benzodiazepine intake over the next 3 weeks tended to be more successful in the flumazenil group. The results are discussed with reference to possible changes in the GABA-benzodiazepine system in long-term benzodiazepine users. 相似文献