全文获取类型
收费全文 | 10519篇 |
免费 | 882篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 117篇 |
儿科学 | 373篇 |
妇产科学 | 218篇 |
基础医学 | 1497篇 |
口腔科学 | 204篇 |
临床医学 | 948篇 |
内科学 | 2283篇 |
皮肤病学 | 204篇 |
神经病学 | 1006篇 |
特种医学 | 261篇 |
外科学 | 1788篇 |
综合类 | 89篇 |
一般理论 | 4篇 |
预防医学 | 780篇 |
眼科学 | 146篇 |
药学 | 622篇 |
中国医学 | 33篇 |
肿瘤学 | 855篇 |
出版年
2023年 | 61篇 |
2022年 | 117篇 |
2021年 | 272篇 |
2020年 | 168篇 |
2019年 | 289篇 |
2018年 | 345篇 |
2017年 | 262篇 |
2016年 | 241篇 |
2015年 | 276篇 |
2014年 | 391篇 |
2013年 | 464篇 |
2012年 | 645篇 |
2011年 | 663篇 |
2010年 | 422篇 |
2009年 | 349篇 |
2008年 | 485篇 |
2007年 | 553篇 |
2006年 | 511篇 |
2005年 | 471篇 |
2004年 | 419篇 |
2003年 | 383篇 |
2002年 | 360篇 |
2001年 | 322篇 |
2000年 | 322篇 |
1999年 | 313篇 |
1998年 | 102篇 |
1997年 | 87篇 |
1996年 | 87篇 |
1995年 | 85篇 |
1994年 | 84篇 |
1993年 | 58篇 |
1992年 | 198篇 |
1991年 | 200篇 |
1990年 | 172篇 |
1989年 | 159篇 |
1988年 | 117篇 |
1987年 | 135篇 |
1986年 | 122篇 |
1985年 | 87篇 |
1984年 | 69篇 |
1983年 | 49篇 |
1982年 | 28篇 |
1981年 | 37篇 |
1979年 | 57篇 |
1978年 | 45篇 |
1977年 | 37篇 |
1976年 | 32篇 |
1975年 | 31篇 |
1974年 | 36篇 |
1973年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Antiviral immune responses modulate the nature of central nervous system (CNS) disease in a murine model of multiple sclerosis 总被引:4,自引:0,他引:4
Summary: In animals and in humans, T-cell therapy can cure advanced disseminated leukemia that would otherwise be fatal. The therapeutic effect of immune T cells is quantitative. As the dose of effector T cells is increased, survival is proportionately increased. Therefore, effective T-cell therapy is predicated on the ability to procure large numbers of immune effector T cells. By using cultured T cells, the number of immune T cells can be increased in vivo substantially above che level achievable by vaccination. The survival of cultured T ceils in vivo is dependent upon both the culture conditions used and the therapeutic regimens employed. Under appropriate conditions, cultured T ceils can proliferate in vivo in response to stimulation by antigen, distribute widely and survive long term to provide effector function and immunologic memory. Given that T cells recognize peptides. the need for immunization with tumor can be circumvented by immunization with peptide. Peptide-specific T cells and the progeny of single T-cell clones can provide the necessary cellular functions to eradicate disseminated murine leukemia. The ability of cloned T cells to similarly provide substantial measurable immunity in humans has been validated in clinical trials. By priming with peptides and by using established culture conditions, T-cell therapy can now be directed against virtually any antigen within the host T-cell repertoire. The major remaining question to be answered is which proteins and which peptides are the most suitable targets for T-cell therapy trials. 相似文献
32.
A Llopis M Morales R Rodriguez 《Journal of environmental pathology, toxicology and oncology》1992,11(3):169-175
Dietary factors are widely considered to be largely responsible for the different cancer incidences observed in different populations. In the present study we investigated the possible influence of dietary habits on the incidence of digestive cancer in the provinces of Spain. Data on specific mortality due to digestive cancer corresponding to the period 1975 to 1985 were obtained from the Instituto Nacional de Estadística. Nutritional data on the different provinces were in turn gathered from the Instituto de Nutrición del Consejo Superior de Investigaciones Científicas. The information was processed by the SPSS statistical software package. Lifestyle and socio-cultural factors are found to influence dietary risk factors in digestive cancer, particularly among women. The most significant correlations with the different cancers studied corresponded to total energy intake (responsible for 27.4% of variance), animal fats, and smoked fish and coffee. The latter is related to oral and esophageal cancer in particular (responsible for 15.4% of variance). Consumption of carrots and frozen vegetables is responsible for 6.5% of variance, vs. 4.4% of variance for alcoholic beverages, sugar, and Vitamin D. Differences are noted between both the sexes and their relationship to the different cancers studied. 相似文献
33.
Abnormal muscle and skin mitochondria in family with myoclonus, ataxia, and deafness (May and White syndrome).
下载免费PDF全文
![点击此处可从《Journal of neurology, neurosurgery, and psychiatry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J Vaamonde J Muruzabal T Tun N Perez J Artieda M Rodriguez J A Obeso 《Journal of neurology, neurosurgery, and psychiatry》1992,55(2):128-132
A mother and two of her daughters had deafness and cortical reflex myoclonus; the mother also had mild truncal ataxia. Muscle and skin biopsy specimens revealed abundant ragged-red fibres and abnormal mitochondria. The son of one of the daughters had sensorineural deafness. Three other grandchildren were asymptomatic. The two daughters also had diabetes mellitus, hypertension and cardiomyopathy. Another daughter died of renal failure. The mother lost her hearing in her 70s, one daughter in her 30s, and the other daughter and the grandson in their 20s. The mother has had transient episodes (24-48 hours) of temporal disorientation, severe action myoclonus, and ataxia for about eight years. This is the first reported family with inherited deafness, myoclonus, and ataxia with mitochondrial pathology. 相似文献
34.
Congenital oesophagobronchial fistula in an adult involving left main bronchus. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Thorax》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M Moreno Azcoita J C Ruiz de Adana L Snchez Urdazpal C Crcamo J M Jover Navaln J L Ramos Rodriguez 《Thorax》1994,49(8):835-836
Congenital fistulae between the tracheobronchial tree and oesophagus usually originate from the lower end of the trachea or right main bronchus. The case history is presented of a man in whom a fistula between the oesophagus and left main bronchus was not diagnosed until the age of 48. 相似文献
35.
Nuno Fonseca Filomena Caetano José Santos Filipe Seixo Leonel Bernardino Isabel Silvestre Paula Cardoso Filomena Segurado Lopes Inês 《Revista portuguesa de cardiologia》2004,23(3):365-375
INTRODUCTION: In patients (pts) with atrial fibrillation (AF) of more than 48 hours' duration, electrical cardioversion (ECV) should only be performed after 3 weeks of effective anticoagulation. Transesophageal echocardiography (TEE) allows earlier ECV; however, despite exclusion of thrombi in the atrium and left atrial appendage (LAA), cases of thromboembolism related to ECV have been documented in AF. To define a low-risk group for cardioversion without previous anticoagulation, pts were selected for immediate ECV if no thrombi or dynamic spontaneous echo contrast (auto-contrast) were found after TEE and if LAA velocity was more than 0.25 m/sec. METHODS AND RESULTS: We performed TEE in 31 consecutive pts referred for ECV for AF of more than 48 hours' duration and without previous anticoagulation. After TEE the pts eligible for immediate ECV began anticoagulation with low molecular weight heparin (enoxaparin), subcutaneously in therapeutic doses, together with warfarin immediately before cardioversion. Enoxaparin was continued until an INR of over 2 was reached. Based on the TEE findings, the pts were divided in 2 groups: immediate ECV, group A, 20 pts with a mean age of 62 +/- 13 years, 6 female; and conventional therapy with warfarin before ECV, group B, 11 pts, mean age of 67 +/- 10 years (p < 0.05), 2 female. None of the pts in either group had mitral stenosis or previous episodes of thromboembolism. The mean transverse diameter of the left atrium in the 31 pts was 47 +/- 4.5 mm, without statistically significant differences between the 2 groups. Of the 11 pts in group B, 3 had a thrombus in the LAA, 6 dynamic spontaneous echo contrast and the remainder LAA velocities of less than 0.25 m/sec. ECV was achieved in all the pts, with no complications. Oral anticoagulation was maintained for at least a month. At one month, sinus rhythm was maintained in 75% of group A and 45% of group B (p < 0.01). CONCLUSION: In pts with AF of more than 48 hours' duration and no previous history of thromboembolism, the use of our exclusion criteria during TEE enabled stratification of a low-risk population for immediate ECV, which was accomplished effectively and safely in 2/3 of the pts. This strategy is associated with early symptomatic improvement, and may contribute to maintenance of sinus rhythm after one month, which was significantly better than in the pts who had prolonged therapy with warfarin before ECV, despite the differences found in age and left ventricular function. 相似文献
36.
Kimberly M Miller Michael S Okun Hubert F Fernandez Charles E Jacobson Ramon L Rodriguez Dawn Bowers 《Movement disorders》2007,22(5):666-672
Depression is common in Parkinson's disease (PD) and affects 30 to 50% of all patients. In contrast to the wealth of research on depression in PD, little is known about the occurrence of depression in other movement disorders. The primary objective of the current study was to determine whether the high prevalence of depression symptoms seen in PD is also found in other movement disorders, by directly comparing rates of specific depression symptoms and depression severity across PD, dystonia, and essential tremor (ET). Three hundred and fifty-four patients with PD, 83 patients with dystonia, and 53 patients with ET completed the Beck Depression Inventory (BDI). We found no significant between-groups differences for depression severity, frequency, or endorsement of specific depression symptoms. Forty-eight percent of PD patients, 37.3% of dystonia patients, and 34% of ET patients were found to be at least mildly depressed (BDI score of 10 or higher). The most commonly endorsed symptoms were fatigability, difficulty with work, anhedonia, and sleep disturbance. Clinicians should be aware that depression is a frequent problem in dystonia and ET, in addition to PD, and inquire about depression symptoms in these patients so that they can be appropriately treated. 相似文献
37.
Andrés A Rodriguez Michael D Olson Kevin M Miller 《Ophthalmic surgery, lasers & imaging》2007,38(1):23-26
BACKGROUND AND OBJECTIVES: To determine differences in the amount of work involved in caring for functionally monocular patients who undergo cataract surgery compared with binocularly sighted patients. PATIENTS AND METHODS: This was a retrospective study that included 100 consecutive functionally monocular patients and 100 binocularly sighted control patients matched by age (+/-5 years) and date of surgery ( +/-1 year). Office records were reviewed to determine several measures of office and operating room work effort. RESULTS: There was no difference between groups in preoperative telephone calls (P = .136), postoperative telephone calls (P = .580), preoperative office visits (P = .875), postoperative office visits (P = .601), or the number of times surgery was scheduled (P = 1.00). Monocular patients required more time for surgery (37.4 minutes) than binocular patients (32.4 minutes) (P= .010). CONCLUSIONS: It takes longer to perform cataract surgery on functionally monocular patients than on binocularly sighted patients. 相似文献
38.
39.
Diet and chronic atrophic gastritis: a case-control study 总被引:2,自引:0,他引:2
E Fontham D Zavala P Correa E Rodriguez F Hunter W Haenszel S R Tannenbaum 《Journal of the National Cancer Institute》1986,76(4):621-627
A hospital-based case-control study of gastric cancer precursor lesions was conducted in a high-risk black population in southern Louisiana. Ninety-three subjects with biopsy-proved advanced chronic atrophic gastritis were compared to two control series: a gastroscopy clinic series and a general hospital-admission series. Dietary case-control differences indicated a protective effect associated with fruit and vegetable intake and with dietary vitamin C and a risk elevation associated with milk consumption. The protective effect associated with consumption of fruits, vegetables, and vitamin C is consistent with findings for gastric cancer and with the etiologic hypothesis of intragastric nitrosation. A twofold increased risk was associated with cigarette smoking. Gastric juice pH, NO3-, and NO2- were determined for subjects undergoing gastroscopy, and comparisons were made between this high-risk U.S. group and a Colombian population with a much greater magnitude of risk; the latter had higher NO3- and NO2- levels. An increase in pH was associated with increasing severity of gastric lesions. Levels of pH and NO2- concentration were significantly correlated (P less than .0005); however, in Louisiana the large difference in NO2- concentration associated with pH elevation is not associated with histopathologic severity. Divergent trends with severity of lesions for NO3- concentration were seen in the two populations. 相似文献
40.
E Buckley P Reilly J Rodriguez Flores R O'Kennedy M R Smyth 《Journal of pharmaceutical and biomedical analysis》1989,7(5):543-547
The adsorptive stripping voltammetric behaviour of F(ab')2 and Fab fragments of anti-mouse immunoglobulin G is described. Conditions were optimized for the determination of these fragments with respect to accumulation potential, accumulation time, scan rate, pulse amplitude, drop size and electrolyte composition. The F(ab')2 and Fab fragments gave rise to behaviour similar to that reported previously for the intact immunoglobulin. 相似文献