全文获取类型
收费全文 | 30788篇 |
免费 | 2406篇 |
国内免费 | 543篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 213篇 |
妇产科学 | 565篇 |
基础医学 | 2889篇 |
口腔科学 | 223篇 |
临床医学 | 3074篇 |
内科学 | 3337篇 |
皮肤病学 | 274篇 |
神经病学 | 405篇 |
特种医学 | 1362篇 |
外科学 | 4531篇 |
综合类 | 2795篇 |
一般理论 | 2篇 |
预防医学 | 1922篇 |
眼科学 | 58篇 |
药学 | 2145篇 |
10篇 | |
中国医学 | 535篇 |
肿瘤学 | 9193篇 |
出版年
2024年 | 33篇 |
2023年 | 561篇 |
2022年 | 1212篇 |
2021年 | 1611篇 |
2020年 | 1310篇 |
2019年 | 1734篇 |
2018年 | 1835篇 |
2017年 | 1518篇 |
2016年 | 1058篇 |
2015年 | 1171篇 |
2014年 | 2522篇 |
2013年 | 2135篇 |
2012年 | 1685篇 |
2011年 | 1889篇 |
2010年 | 1371篇 |
2009年 | 1523篇 |
2008年 | 1736篇 |
2007年 | 1403篇 |
2006年 | 1142篇 |
2005年 | 845篇 |
2004年 | 758篇 |
2003年 | 594篇 |
2002年 | 374篇 |
2001年 | 402篇 |
2000年 | 351篇 |
1999年 | 306篇 |
1998年 | 254篇 |
1997年 | 254篇 |
1996年 | 233篇 |
1995年 | 198篇 |
1994年 | 177篇 |
1993年 | 129篇 |
1992年 | 94篇 |
1991年 | 93篇 |
1990年 | 60篇 |
1989年 | 78篇 |
1988年 | 63篇 |
1987年 | 52篇 |
1986年 | 42篇 |
1985年 | 113篇 |
1984年 | 134篇 |
1983年 | 101篇 |
1982年 | 131篇 |
1981年 | 92篇 |
1980年 | 87篇 |
1979年 | 76篇 |
1978年 | 48篇 |
1977年 | 34篇 |
1976年 | 37篇 |
1975年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
The purpose of this study was to evaluate the ability of MRI to identify a primary site of malignancy in the breast of patients who present clinically with ipsilateral lymph nodes containing metastatic carcinoma but whose physical and mammographic examination are negative. MRI of the breast was performed on four patients using a variety of imaging parameters, all with and without gadolinium contrast. All patients had biopsy-proven adenocarcinoma of the ipsilateral axilla, with negative physical and mammographic examinations. Foci of enhancement assessed visually on precontrast and postcontrast scans (n = 1) and on substraction studies (n = 3) were considered suspicious under the clinical circumstances defined for this study. Lesions identified on MRI were re-identified on ultrasound examination and either preoperative localization for excisional biopsy or tissue sampling was performed. Surgery was performed and histopathologic correlation was obtained in all cases. Primary sites of breast carcinoma were identified in all four patients, with multiple sites of malignancy identified in three of four patients. Breast conservation therapy was made possible for three of four patients based on the results of the MRI study showing sites of malignancy and no features of cancer elsewhere in the breast. Follow-up data of 1, 2, and 5 years of these patients show no evidence of recurrent disease. MRI of the breast is a useful technique for identifying primary sites of malignancy in patients presenting with ipsilateral lymph nodes positive for metastatic adenocarcinoma when the physical and mammographic examinations are negative. 相似文献
12.
G. M. Kiebert A. M. Stiggelbout J. Kievit J. -W. H. Leer C. J. H. van de Velde H. J. C. J. M. de Haes 《Quality of life research》1994,3(3):175-182
Medical treatment of cancer often entails a trade-off between outcomes of two different attributes: quality of life (QOL) and length of life (LL). This process of weighing advantages and disadvantages seems to be influenced by different factors. The main purposes of this study were (a) to investigate the relative importance of different factors on the trade-off and (b) to explore the relationship between these importance ratings and personal characteristics. We asked 199 patients with cancer to indicate to what degree they consider a number of factors to be of importance if they had to choose between two treatment modallties that differ in their expected outcomes concerning QOL and LL. The seven factors were their age at the time of decision, having a partner, having children, inability to work due to side-effects of the treatment, the nature of the side-effects, disease-related life expectancy and baseline QOL. The results indicate that six of the seven factors were of considerable to great importance when a treatment choice had to be made. The negative effects of treatment on the ability to work did not seem to be a very important consideration. Patient age and education were positively associated with importance ratings.Supported by the Dutch Cancer Society (Project IKW 90-13). 相似文献
13.
14.
目的:探讨经尿道等离子前列腺双极汽化电切术(TUPKVP)治疗前列腺增生的效果。方法:回顾性分析580例良性前列腺增生(BPH)患者行TUPKVP的临床资料。结果:中转开放手术2例,切除前列腺组织10~80 g,平均32.5 g。手术时间25~150 min,平均60 min,术中输血10例,无电切综合征(TURS)发生。术后随访2~36个月,患者最大尿流率升高,IPSS症状评分值降低,排尿通畅,疗效好,并发症少。结论:TUPKVP出血少,手术安全,疗效确切,是治疗前列腺增生的有效方法。 相似文献
15.
16.
Ultraviolet Laser-Induced Fluorescence Spectroscopy Diagnosis of Human Stomach Malignant Tissues 总被引:2,自引:0,他引:2
To evaluate the potential of laser-induced autofluorescence spectroscopy for the detection of premalignant lesions of human
stomach, fluorescence properties of stomach tissues have been investigated in vitro and in vivo. A specially made optical
fibre probe and the multichannel fluorescence collection system have been used successfully in our research.
Paper received 26 June 1997; accepted in revised form 31 October 1997. 相似文献
17.
Anjan Banerjee M.Sc. M.S. D.M. Philip Quirke B.M. Ph.D. 《Diseases of the colon and rectum》1998,41(4):490-505
PURPOSE: A review ofin vivo andin vitro models of colorectal cancer is presented. METHODS: A retrospective literature review was performed with reference to CD-ROM Medline and Index Medicus. RESULTS: A comparison of the advantages and disadvantages of the models is presented in addition to a summary of individual model methodology and applications. CONCLUSIONS: Such models are a useful adjunct for surgical research in colorectal oncology.Mr. Banerjee is in receipt of support from the Yorkshire Cancer Research Organization. 相似文献
18.
Summary In vivo prostatic secretion was collected from retired breeder Sprague Dawley rats using a method for isolated perfusion of the rat prostatic urethra. Enzymatic acid phosphatase determination was performed on the collected effluent. Control acid phosphatase secretion was 24.2±2.7 nm over 30 minutes. Intravenous phenylephrine 5 mg/kg stimulated a 10 fold increase in acid phosphatase secretion. The secretion seen with phenylephrine was dose dependent and could be blocked with prazosin, but not yohimbine, atropine, or propranolol. Intravenous -adrenergic agonist isoproterenol caused no increase in the secretion of rat prostatic acid phosphatese. Intravenous administration of the cholinergic agonist pilocarpine also resulted in a dose dependent rise in acid phosphatase secretion. The stimulation seen could be blocked by atropine but not phentolamine or propranolol. The stimulation of acid phosphatase secretion seen with 1 adrenergic or cholinergic agonists was not additive. Intravenous vasoactive intestinal peptide did not stimulate acid phosphatase secretion nor did it augment the secretion induced by 1 adrenergic or cholinergic agonists. Release of acid phosphatase into rat prostatic exocrine secretion is under both 1 adrenergic and cholinergic control.Supported by the US Veterans Administration 相似文献
19.
H. Fujiwara M. Emi H. Nagai T. Nishimura N. Konishi Y. Kubota T. Ichikawa S. Takahashi T. Shuin T. Habuchi O. Ogawa K. Inoue M. H. Skolnick J. Swensen N. J. Camp S. V. Tavtigian 《Journal of human genetics》2002,47(12):0641-0648
The recently identified prostate cancer susceptibility gene ELAC2 (HPC2) harbors two common missense variants, a serine to leucine substitution at residue 217 (Leu217) and an alanine to threonine
substitution at residue 541 (Thr541). We genotyped the two variants in a Japanese cohort consisting of 350 prostate cancer
patients 242 male population controls, and 114 male low-risk controls. Both missense alleles, Leu217 and Thr541, were carried
at higher frequency in Japanese patients than in the controls (Leu217, P = 0.0012; Thr541, P = 0.0145), and the odds ratios associated with carrying these sequence variants were higher in Japanese than in Caucasians.
Although the Leu217 and Thr541 variants of ELAC2 are less common in Japanese than in Caucasians, both variants confer significantly increased risk of prostate cancer in Japanese.
Carriage of these variants was not associated with age at diagnosis, tumor stage, or tumor grade in these Japanese prostate
cancer patients. The allele-specific pattern of risk observed in Japanese and familial Caucasian patients was qualitatively
similar; however, the magnitude of that risk was considerably greater in Japanese than in Caucasians.
Received: September 3, 2002 / Accepted: October 2, 2002 相似文献