首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4196篇
  免费   369篇
  国内免费   39篇
耳鼻咽喉   33篇
儿科学   251篇
妇产科学   76篇
基础医学   574篇
口腔科学   119篇
临床医学   335篇
内科学   926篇
皮肤病学   132篇
神经病学   187篇
特种医学   245篇
外科学   480篇
综合类   255篇
预防医学   431篇
眼科学   76篇
药学   248篇
中国医学   14篇
肿瘤学   222篇
  2023年   43篇
  2022年   67篇
  2021年   95篇
  2020年   59篇
  2019年   69篇
  2018年   109篇
  2017年   95篇
  2016年   108篇
  2015年   150篇
  2014年   185篇
  2013年   247篇
  2012年   225篇
  2011年   192篇
  2010年   179篇
  2009年   154篇
  2008年   164篇
  2007年   166篇
  2006年   164篇
  2005年   135篇
  2004年   123篇
  2003年   110篇
  2002年   120篇
  2001年   89篇
  2000年   87篇
  1999年   92篇
  1998年   122篇
  1997年   115篇
  1996年   121篇
  1995年   82篇
  1994年   90篇
  1993年   56篇
  1992年   53篇
  1991年   58篇
  1990年   41篇
  1989年   58篇
  1988年   55篇
  1987年   46篇
  1986年   53篇
  1985年   47篇
  1984年   31篇
  1983年   20篇
  1982年   29篇
  1981年   21篇
  1980年   27篇
  1979年   20篇
  1977年   17篇
  1976年   27篇
  1975年   21篇
  1974年   18篇
  1973年   32篇
排序方式: 共有4604条查询结果,搜索用时 15 毫秒
1.
We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS.  相似文献   
2.
Seventy seven antral biopsies were collected from patients attending endoscopy clinic at King Khalid University Hospital, Riyadh, Saudi Arabia during a period of six months between December 1988 to May 1989. Of these 69 (89.6%) showed chronic gastritis as well as Helicobacter-like organisms (HLOs) in the biopsy specimens while 63 (81.8%) of biopsies grew Helicobacter pylori on culture. These findings indicate a good correlation between the histological diagnosis of chronic gastritis and isolation of H. pylori on culture.  相似文献   
3.
4.
The potential antidepressant effect of flerobuterol (dl-(fluoro-2 phenyl)-1 t-butylamino-2 ethanol), a new drug related to beta-adrenoceptor agonists, was evaluated and compared with imipramine and salbutamol using classical psychopharmacological tests in mice. Like imipramine and salbutamol, flerobuterol (0.5-32 mg kg-1, ip) fully prevented apomorphine (16 mg kg-1, sc)- and partly reversed reserpine- and oxotremorine-induced hypothermia. At higher doses (16-32 mg kg-1), flerobuterol enhanced the toxic effects of yohimbine. Unlike imipramine, flerobuterol and salbutamol did not reduce immobility duration in the behavioural despair test. Salbutamol and flerobuterol decreased locomotor activity. Flerobuterol did not induce mydriasis, did not prevent oxotremorine-induced tremors or salivary and lacrimal gland secretion and did not reduce reserpine-induced palpebral ptosis. Propranolol (8 mg kg-1, ip) but not alpha-methyl-paratyrosine (75 mg kg-1, ip) prevented the flerobuterol-induced antagonism of apomorphine-induced hypothermia. Our results suggest that flerobuterol demonstrates potential antidepressant activity, which could be related to beta-adrenoceptor activation in mice.  相似文献   
5.
6.
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.  相似文献   
7.
BACKGROUND: Development of more than one primary melanoma in a patient is a relatively uncommon but well-recognized phenomenon. Its frequency has ranged from 1.2% to 8.2% in several series. This subgroup of patients with multiple primary lesions has not been characterized sufficiently. We report the experience of the Melanoma Unit of University Hospital Spedali Civili of Brescia, Italy. METHOD: Study subjects were drawn from 1240 patients with histologically confirmed melanoma, including melanoma in situ. From this group, multiple melanomas developed in 47 patients (3.79%). Every one of our patients has been taught to perform self-examination of the skin to detect suspicious pigmented lesions. RESULTS: Of the 47 patients described in this study, 38 had two primary melanomas, 7 had three melanomas and 2 had 5 and 10 melanomas, respectively. Mean age at first diagnosis was 46.2 years. The majority of subsequent melanomas (74.5%) were removed within 5 years of the initial operation. Synchronous lesions were found in 10 patients. In male patients, the lesion appeared most frequently on the trunk; in female patients, melanoma appeared mostly on the lower extremities. The second primary melanomas developed in the same anatomic region from the first in 53.2% of our patients. The proportion of in situ to invasive melanomas was greater for the second melanomas compared with the first melanomas. Regarding invasive melanomas, the mean thickness of the first melanomas was 1.31 mm compared with 0.66 mm for the second ones. Dividing patients into two groups, of more and less than 50, it is highlighted that in older patients synchronous lesions appear more frequently (36.4% vs. 8.0%); the median time interval between sequential melanomas is longer (84 vs. 63.7 months); and the ratio between the primary and secondary melanoma mean thickness is lower (1.21 : 1.08 vs. 1.43 : 0.63 mm). CONCLUSIONS: The study confirms that second primary melanoma is usually thinner than the first lesion, and it is more common in the same region of the body as the initial melanoma. The highest risk for a second melanoma is during the first 5 years, but a much longer time interval of 28 years is possible. Continued medical follow-up with complete skin examinations seems prudent, but it is very important to promote self-skin evaluation in patients to detect not only metastases but also subsequent primary melanomas in their earliest phases.  相似文献   
8.
Abstract A female patient exhibiting functional hearing loss in her left ear demonstrated reduced amplitude of P3 component in event-related potentials (ERP) to left monaural stimulation, with preserved N1 and N2 components to stimulation of either ear. This result suggested that stimuli in the affected ear were conducted successfully up to the auditory cortex but that further processing in higher brain regions was 'repressed'. Event-related potential examination for such hysterical disorders could be useful in clarifying their brain mechanism and offer a useful diagnostic clue to its nature.  相似文献   
9.
It is posited that diarrhoeal illness during one period has influence on diarrhoeal illness in a subsequent period. This relationship may potentially mask the association between malnutrition and subsequent diarrhoea. To test this, we analysed data on cross-sectional anthropometry in combination with data on diarrhoeal morbidity collected longitudinally in a community-based study of 1262 children (aged 6-60 months) during March-December, 1976, in Matlab, Bangladesh. The results confirmed the posited relationship between diarrhoeal morbidities in two consecutive periods and showed that the risks of diarrhoeal attack and longer diarrhoeal illness increased more than threefold during the 2 months following diarrhoeal illness during the preceding 2 months (previous diarrhoea). Children with no previous diarrhoea indicated a positive association between malnutrition and subsequent diarrhoea, but the pattern found among children with previous diarrhoea was not understandable. Logistic regression analyses performed separately for younger and older children showed that controlling for effects of previous diarrhoea, maternal illiteracy and household poverty, severe malnutrition as assessed by weight-for-age was found to be strongly associated with the risk of longer diarrhoeal illness in a 2-month interval in the age group 24-60 months; in the same age group the association with the risk of diarrhoeal attack was significant at the 10 per cent level. No such association for malnutrition, however, was found in the age group 6-23 months.  相似文献   
10.
The serum ceruloplasmin concentration was determined in cancer patients before and after radiotherapy, and after relapse of cancer, The ceruloplasmin concentration in patients who responded to therapy, decreased to the range of normal controls. In patients who did not respond to treatment, the ceruloplasmin concentration was more or less elevated. In patients with relapse of cancer, the ceruloplasmin concentration was higher than before treatment.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号