全文获取类型
收费全文 | 31466篇 |
免费 | 1560篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 405篇 |
儿科学 | 1655篇 |
妇产科学 | 684篇 |
基础医学 | 3440篇 |
口腔科学 | 695篇 |
临床医学 | 1902篇 |
内科学 | 7030篇 |
皮肤病学 | 865篇 |
神经病学 | 2001篇 |
特种医学 | 1078篇 |
外科学 | 4293篇 |
综合类 | 877篇 |
一般理论 | 20篇 |
预防医学 | 1554篇 |
眼科学 | 1594篇 |
药学 | 2711篇 |
中国医学 | 200篇 |
肿瘤学 | 2136篇 |
出版年
2023年 | 217篇 |
2022年 | 520篇 |
2021年 | 1058篇 |
2020年 | 561篇 |
2019年 | 699篇 |
2018年 | 895篇 |
2017年 | 624篇 |
2016年 | 796篇 |
2015年 | 769篇 |
2014年 | 1208篇 |
2013年 | 1462篇 |
2012年 | 2179篇 |
2011年 | 2337篇 |
2010年 | 1268篇 |
2009年 | 1047篇 |
2008年 | 1633篇 |
2007年 | 1738篇 |
2006年 | 1708篇 |
2005年 | 1491篇 |
2004年 | 1382篇 |
2003年 | 1176篇 |
2002年 | 1050篇 |
2001年 | 741篇 |
2000年 | 732篇 |
1999年 | 599篇 |
1998年 | 276篇 |
1997年 | 194篇 |
1996年 | 167篇 |
1995年 | 172篇 |
1994年 | 139篇 |
1993年 | 115篇 |
1992年 | 371篇 |
1991年 | 379篇 |
1990年 | 342篇 |
1989年 | 335篇 |
1988年 | 289篇 |
1987年 | 254篇 |
1986年 | 234篇 |
1985年 | 232篇 |
1984年 | 171篇 |
1983年 | 136篇 |
1981年 | 92篇 |
1979年 | 157篇 |
1978年 | 97篇 |
1977年 | 81篇 |
1975年 | 85篇 |
1974年 | 101篇 |
1973年 | 92篇 |
1972年 | 118篇 |
1970年 | 78篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
11.
Circulating immune complexes in pre-eclampsia. 总被引:3,自引:0,他引:3
Serum samples from 20 non-pregnant women, 30 women with normal pregnancy and 50 women with pregnancy associated with pre-eclampsia were tested for circulating immune complexes using the polyethyleneglycol precipitation method. A highly significant positive correlation was found between circulating immune complexes and severe pre-eclampsia (BP greater than 140/90 mm Hg, albuminuria greater than 0.25 g/l). In contrast to this the difference in immune complex levels between non-pregnant subject, normal pregnancy cases and patients with mild pre-eclampsia was not statistically significant. A significant positive correlation was found between the level of circulating immune complexes and the severity of albuminuria. These findings suggest that circulating immune complexes, though not seeming to play an aetiological role in pre-eclampsia may very well be involved in its pathogenesis. 相似文献
12.
De-coupling of cognitive performance and cerebral functional response during working memory in schizophrenia. 总被引:4,自引:0,他引:4
Working memory dysfunction is considered to be fundamental to the cognitive and clinical features evident in schizophrenia. Functional neuroimaging studies have begun to elucidate the neurobiological basis of such deficits, however, interpretation of these studies may be confounded by performance impairment, when the cognitive load exceeds the limited response capacity of patients with schizophrenia. In this study, patients were pre-selected on the basis of intact performance on a relatively low-load verbal working memory task, in order to mitigate against performance confounds. Subjects included 20 right-handed male subjects with chronic schizophrenia, and 20 right-handed, age-matched, male healthy controls, without personal or familial psychiatric history. All subjects underwent fMRI scanning whilst performing a verbal n-back task. There were no significant between-group differences in target identification; the patient group showed a significantly increased mean response latency. Both groups demonstrated robust fronto-parietal activation. In the control subjects, the power of functional response was positively correlated with reaction time in bilateral posterior parietal cortex, however, this coupling of behavioural performance and cerebral response was not evident in the patients. This deficit, apparent within the performance capacity of the patients, may represent a fundamental abnormality in schizophrenia, and may compromise performance at higher cognitive loads. 相似文献
13.
Sandeep Mahajan Suresh C Tiwari Vikram Kalra Dipankar M Bhowmik Sanjay K Agarwal Suresh C Dash Parveen Kumar 《Peritoneal dialysis international》2005,25(5):473-477
BACKGROUND: Staphylococcus aureus-associated peritonitis and catheter exit-site infections (ESIs) are important causes of hospitalization and catheter loss in patients undergoing chronic peritoneal dialysis. Intranasal and topical use of mupirocin has been found to be an effective strategy in decreasing S. aureus-related infectious complications in persons who are carriers of S. aureus; however, there is no consensus regarding the prophylactic use of mupirocin irrespective of carrier status. We aimed to determine the potential effectiveness of application of mupirocin cream at the catheter exit site in preventing ESI and peritonitis irrespective of carrier status in a tropical country such as India. METHODS: This prospective historically controlled study was done in a total of 40 patients. From August 2003, all patients, incident and prevalent, were instructed to apply 2% mupirocin cream daily to the exit site instead of the older practice of povidone-iodine and gauze dressing. Patients were not screened to determine whether they were S. aureus carriers. The infection-related data for 1 year, until July 2004, were compared with the historical control, which was infection-related data for the year preceding the year of mupirocin application. RESULTS: Mean age of the study population was 62 years, with 61.8% being male and 64.3% being diabetic. Local application of mupirocin led to a significant reduction in the incidence density per patient-month of both ESI and peritonitis compared to controls (0.15 vs 0.37 and 0.37 vs 0.67, p = 0.01 for both). This amounted to a relative reduction of 60.5% and 55% respectively. ESI and peritonitis due to S. aureus were also significantly lower in the study group compared to controls (incidence density per patient-month 0.05 vs 0.13 and zero vs 0.17 respectively, p < 0.01 for both). There occurred no catheter removal due to infection-related complications during the study period compared to two during the control period. None of the patients reported a mupirocin-related adverse effect. CONCLUSIONS: Daily application of mupirocin at the exit site is a well-tolerated and effective strategy in reducing the incidence of ESI and peritonitis in a tropical country such as India. It can thus significantly reduce morbidity, catheter loss, and transfer to hemodialysis in peritoneal dialysis patients. 相似文献
14.
Nand L. Sharma Vikram K. Mahajan Neelam Gupta Nitin Ranjan and Anju Lath 《Journal of cutaneous pathology》2009,36(4):486-492
Ehlers-Danlos syndrome – vascular type, the only lethal form, is rarely reported in dermatology literature. It is characterized by translucent, atrophic skin, easy bruising, arterial, intestinal and/or uterine fragility manifesting as varicose veins, aneurysms and vascular/visceral/uterine rupture. As its dermatopathologic features are not well elucidated, diagnosis is often made after a catastrophic complication or at autopsy. This 36 year-old non-consanguineous male had brown-black plaques with atrophy and frequent ulceration over legs and dorsal feet and tortuous varicose veins around ankles for the past 15 years. Perivenous skin was translucent and hypopigmented. He had multiple and ecchymotic keloids and small atrophic, pityriasis versicolor-like lesions over trunk. He did not have hypermobile/hyperextensible skin and joints and showed no systemic or investigative abnormality. Histopathologic features of atrophic lesion included blood extravasation in atrophic epidermis/dermis, focal clustering and dilatation of blood vessels, malformed vessel walls, abundant hemosiderin in the dermis and homogenously stained/whorled patterned collagen especially around blood vessels. Pathology of keloidal lesion showed new collagen and vascular fragility. These histopathologic features appear of diagnostic value especially in patients who have compatible clinical findings but cannot afford confirmation by biochemical testing for abnormal synthesis of type III procollagen or identification of mutations in the COL3A1 gene. 相似文献
15.
Herniation of a thoracic disc in an acromegalic giant is reported. Degenerative changes in the spine in association with dorsal kyphosis, and the additional strain, resulted in the disc prolapse. 相似文献
16.
17.
J H Newcorn J M Halperin J M Healey J D O'Brien D M Pascualvaca L E Wolf A Morganstein V Sharma J G Young 《Journal of the American Academy of Child and Adolescent Psychiatry》1989,28(5):734-738
To assess the relationship between the DSM-III criteria for attention deficit disorder with hyperactivity (ADDH) and the DSM-III-R criteria for attention-deficit hyperactivity disorder (ADHD), children from an inner city parochial school were evaluated using a 30-item teacher questionnaire consisting of the DMS-III and DSM-III-R criteria for these disorders, the revised Conners Parent and Teacher Questionnaires, and a continuous performance test. Diagnostic groups were established based on teacher ratings of the DSM items and evaluated in relation to the rating scale data and continuous performance test. While children who were identified by teachers as having ADDH almost always satisfied the criteria for ADHD, a new group of children who were hyperactive and impulsive but less clearly inattentive also met the criteria for ADHD. Implications of the change in diagnostic criteria are discussed. 相似文献
18.
SETTING: Homes in Delhi, India. OBJECTIVE: To study the reach of mass media campaigns and their impact on awareness about tuberculosis (TB) control among homemakers/housewives. DESIGN: A community-based cross-sectional survey among homemakers residing in Delhi for more than 6 months. RESULTS: Of a total of 920 women interviewed, about 74.2% had seen specific TB-related health messages in one or more of the mass media. The maximum number of subjects could recall having seen billboards or television campaigns. The percentage of respondents who had correct information about various aspects of the disease was higher among those who had seen TB campaigns on any of the mass media. The effectiveness of radio and newsprint in communicating TB messages was found to be more limited than that of television and billboards. CONCLUSION: The mass media can be effective in getting messages about TB across to the community of women who are homemakers, especially in developing countries. In view of our findings, it may be recommended that television and billboards be used as tools for reaching out to them with specific campaigns regarding TB control, and that the use of these media should be strengthened further. 相似文献
19.
We thank Coceani and L'Abbate for their comments on our paper.We concur that pathophysiology cannot be inferred fromcoronary lumenography alone, and this was one of thekey motivations in conducting the present study. 相似文献
20.
V. K. Sharma G. Tsivgoulis A. Y. Lao M. Flaster J. L. Frey M. D. Malkoff A. V. Alexandrov 《European journal of neurology》2007,14(2):237-240
Although common carotid artery (CCA) occlusions are rare, acute clinical presentations vary from mild to devastating strokes primarily due to tandem occlusions in the intracranial arteries. Three patients with acute CCA occlusions were treated with systemic tissue plasminogen activator (TPA). Blood pressures were kept at the upper limits allowed with TPA therapy with fluid balance and the 'head-down' position. Recanalization occurred in intracranial vessels only. Marked early neurological improvement occurred in two of three patients. CCA occlusions should not be considered contra-indication to systemic thrombolysis. 相似文献