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   2832篇
  免费   153篇
  国内免费   20篇
耳鼻咽喉   145篇
儿科学   67篇
妇产科学   61篇
基础医学   354篇
口腔科学   91篇
临床医学   199篇
内科学   641篇
皮肤病学   64篇
神经病学   264篇
特种医学   107篇
外科学   357篇
综合类   27篇
预防医学   112篇
眼科学   101篇
药学   171篇
中国医学   10篇
肿瘤学   234篇
  2023年   31篇
  2022年   40篇
  2021年   86篇
  2020年   41篇
  2019年   57篇
  2018年   81篇
  2017年   57篇
  2016年   75篇
  2015年   76篇
  2014年   106篇
  2013年   112篇
  2012年   193篇
  2011年   218篇
  2010年   123篇
  2009年   91篇
  2008年   149篇
  2007年   194篇
  2006年   178篇
  2005年   166篇
  2004年   151篇
  2003年   157篇
  2002年   133篇
  2001年   36篇
  2000年   39篇
  1999年   49篇
  1998年   22篇
  1997年   27篇
  1996年   15篇
  1995年   13篇
  1994年   12篇
  1993年   16篇
  1992年   23篇
  1991年   27篇
  1990年   18篇
  1989年   20篇
  1988年   22篇
  1987年   16篇
  1986年   22篇
  1985年   23篇
  1984年   13篇
  1983年   6篇
  1982年   7篇
  1981年   6篇
  1979年   11篇
  1976年   5篇
  1971年   6篇
  1968年   3篇
  1967年   5篇
  1966年   6篇
  1965年   4篇
排序方式: 共有3005条查询结果,搜索用时 171 毫秒
1.
2.
Pancreatic metastasis of malignant melanoma is rarely diagnosed while the patient is alive. We report a case of metastatic melanoma of the pancreas in a 35-year-old woman presenting with a solid mass of the pancreas. Her past medical history included a radical hysterectomy 2 years previously for malignant melanoma of the vagina. Twelve months later, lung metastasis was also resected. EUS-guided fine needle aspiration (EUS-FNA) identified that the pancreatic tumor was histologically and immunohistochemically identical to the surgical specimen of her lung neoplasm. Imaging studies including US, CT, and MRI have limited value to distinguish the tumors from primary ductal adenocarcinoma. EUS-FNA can provide tissue diagnosis from pancreatic masses, specifically when other modalities have failed.  相似文献   
3.
4.
A 52-year-old woman who had had 6 months of chemotherapy using mitomycin C and cisplatin for cervical cancer presented with hemolytic uremic syndrome. Conventional plasmapheresis using whole-plasma fraction was ineffective. However, plasmapheresis using the cryosupernatant fraction dramatically improved symptoms of hemolytic anemia and thrombocytopenia in this case. The activity of factor VIII in the cryosupernatant fraction of plasma as a replacement fluid decreased after removal of cryoprecipitate, indicating effective removal of von Willebrand factor. The pathogenesis of her hemolytic uremic syndrome may have been associated with von Willebrand factor multimers contained in the cryoprecipitate of plasma. Similar use of the cryosupernatant fraction of plasma could not be found in other reports of cases of hemolytic uremic syndrome. Plasmapheresis using the cryosupernatant fraction of plasma may improve refractory hemolytic uremic syndrome.  相似文献   
5.
6.
Background: In Japan a new long‐term care insurance (LTCI) system, the so‐called ‘Kaigo‐Hoken’, was started in April 2000. The present study analyzes the change in the type of destination after discharge from a senile dementia therapy ward before and after the implementation of LTCI at Fukuoka Prefectural Onga Hospital, Japan. Methods: The present study examines data from 199 inpatients discharged from the Fukuoka Prefectural Onga Hospital that had been diagnosed with dementia and met the DSM IV criteria for Alzheimer's type, vascular dementia or other type of dementia. For the purposes of comparison two periods were defined, ‘the first period’ was defined as the period from 1 April 1999 to 31 March 2000, before LTCI was implemented, while ‘the second period’ was defined as the period from 1 April 2000 to 31 March 2001, after LTCI had started. Subject data was analyzed on the basis of where the subject had resided pre‐admission and their destination after discharge using the following classifications: nursing home or geriatric care facility, hospitalization, home and death. Results: While the certification rate of inpatients regarding long‐term care increased slightly in the second period, no significant change was observed based on where the subject had resided pre‐admission and their destination after discharge between the first and second periods. Conclusions: While LTCI is essential for Japan, it is necessary that people with dementia in senile dementia therapy wards are encouraged to return to their homes under the care and support of LTCI.  相似文献   
7.
To investigate the usefulness of the frontal assessment battery (FAB) as a brief assessment for diagnosis in patients with dementia, we examined cognitive function using the FAB, Mini-mental state examination (MMSE), Kana-hiroi test, and Raven's colored progressive matrices (RCPM). Subjects were 82 senile patients having amnesia as a complaint including 28 Alzheimer's disease (AD), 14 frontotemporal dementia (FTD), 17 vascular dementia (VD), 13 mild cognitive impairment (MCI), and 10 healthy persons. We discussed the difference of scores in different types of dementia. In the FAB, the scores of healthy persons and MCI were much higher compared with the scores of all types of dementia. There were high correlation between FAB and MMSE, Kana-hiroi test, and RCPM. Although some subjects showed normal score in MMSE and/or RCPM, they showed low score in FAB. Based on this, FAB is efficient for the differential diagnosis of dementia as brief screening tool.  相似文献   
8.
Information concerning surgical treatment of adult patients with chronic sinusitis was obtained through questionnaires from 434 hospitals in Japan. The hospitals were authorized for an in-service otorhinolaryngological training institute by the Oto-Rhino-Laryngological Society of Japan. The questionnaires were sent to the hospitals in December, 1989, and answers were obtained from 370 hospitals within 2 months, an 85.3% response rate. The following results were obtained. In 96.2% of the hospitals, permaxillary sinus surgery was performed on patients whose maxillary and ethmoid lesions were severe. With moderate lesions of both the maxillary and ethmoid sinuses, permaxillary sinus surgery and endonasal sinus surgery were performed in 76.0% and 24.9%, respectively. Application of an endoscope for sinus surgery was reported by 89 hospitals. In January, 1990, a further survey was sent to the 89 hospitals where endoscopic sinus surgery was performed. Questionnaire responses were obtained from 75 hospitals. Rigid endoscope was used most frequently and operative microscope was also used. Endoscopy was applied to all of the sinus surgery procedures in 21.6%, and to a portion of the procedures in 74.3% of the hospitals. About 50% of the hospitals performed endoscopic surgery in fewer than 30% of sinus surgery cases. When questioned as whether endoscopic surgery had been successful, 42.6% said yes, 10.7% said no, and 42.6% were unsure.  相似文献   
9.
Polymeric peptides containing defined repetitive or cyclic structures of RGDT sequence, (RGDT)n (n = 1 to 11) and cyclo(RGDT)n (n=2 to 4), at a dose of 500 μg exhibited an inhibitory effect on experimental lung metastasis upon co-injection with tumor cells and the magnitude of the effect increased in parallel with the increase of degree of repetition of the RGDT sequence. The conjugation of (RGDT)n (n = 1, 5, 11) with poly(ethylene glycol), PEG as a polymeric carrier led to enhanced inhibition of lung metastasis in proportion to the degree of RGDT sequence repetition and in a dose-dependent manner. Multiple i.v. administrations of PEG-(RGDT)11, at 2-day and 3-day intervals before the excision of primary tumors, effectively inhibited spontaneous lung metastasis by s.c. inoculation of tumors, whereas (RGDT)11 exhibited inhibition of lung metastasis only when given at 2-day intervals. This indicates that the conjugation of PEG with (RGDT)n allowed the prolongation of administration interval, implying a sustained inhibitory effect on tumor metastasis. In support of this supposition, a decrease in the arrest of radiolabeled tumor cells in the lungs was observed when PEG-(RGDT)11 was co-injected i.v. with tumor cells, or injected i.v. one day before tumor inoculation. In contrast, (RGDT)11 significantly inhibited the tumor cell arrest in the lungs only upon co-injection with tumor cells. We also noted that (RGDT)n, cyclo(RGDT)n and PEG-(RGDT)11 inhibited tumor cell invasion into Matrigel in a concentration-dependent manner and in proportion to the degree of RGDT sequence repetition, indicating that the peptide-mediated antimetastatic effect is partly associated with the anti-invasive potential. Thus, the conjugation of anti-cell adhesive and antimetastatic RGDT peptide with PEG might provide a therapeutically promising basis for the prevention of cancer metastasis (“anti adhesion therapy”).  相似文献   
10.
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