全文获取类型
收费全文 | 5489篇 |
免费 | 416篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 163篇 |
妇产科学 | 101篇 |
基础医学 | 703篇 |
口腔科学 | 71篇 |
临床医学 | 798篇 |
内科学 | 911篇 |
皮肤病学 | 104篇 |
神经病学 | 518篇 |
特种医学 | 163篇 |
外科学 | 602篇 |
综合类 | 62篇 |
一般理论 | 2篇 |
预防医学 | 821篇 |
眼科学 | 107篇 |
药学 | 308篇 |
中国医学 | 4篇 |
肿瘤学 | 454篇 |
出版年
2022年 | 39篇 |
2021年 | 101篇 |
2020年 | 72篇 |
2019年 | 93篇 |
2018年 | 112篇 |
2017年 | 95篇 |
2016年 | 86篇 |
2015年 | 119篇 |
2014年 | 146篇 |
2013年 | 213篇 |
2012年 | 295篇 |
2011年 | 363篇 |
2010年 | 205篇 |
2009年 | 166篇 |
2008年 | 300篇 |
2007年 | 329篇 |
2006年 | 302篇 |
2005年 | 299篇 |
2004年 | 255篇 |
2003年 | 301篇 |
2002年 | 239篇 |
2001年 | 124篇 |
2000年 | 108篇 |
1999年 | 106篇 |
1998年 | 75篇 |
1997年 | 51篇 |
1996年 | 56篇 |
1995年 | 60篇 |
1994年 | 38篇 |
1993年 | 30篇 |
1992年 | 63篇 |
1991年 | 60篇 |
1990年 | 62篇 |
1989年 | 73篇 |
1988年 | 55篇 |
1987年 | 61篇 |
1986年 | 54篇 |
1985年 | 56篇 |
1984年 | 47篇 |
1983年 | 48篇 |
1982年 | 29篇 |
1981年 | 27篇 |
1979年 | 37篇 |
1978年 | 38篇 |
1974年 | 26篇 |
1973年 | 31篇 |
1972年 | 25篇 |
1971年 | 28篇 |
1969年 | 32篇 |
1966年 | 27篇 |
排序方式: 共有5910条查询结果,搜索用时 46 毫秒
1.
Medicine, Health Care and Philosophy - A life-threatening illness such as cancer can bring about much existential suffering and a disconnect to self in spite of surviving cancer. In my recent... 相似文献
2.
3.
4.
5.
Betlach Charles J. Arnold John D. Frost R. Wayne Leese Philip T. Gonzalez Mario A. 《Pharmaceutical research》1987,4(5):409-411
The bioavailability of a new sustained-release potassium chloride (KC1) tablet, designed for once-a-day dosing, was compared to a KC1 elixir using urinary excretion data. The study utilized 25 male volunteers dosed in a crossover design in a dietary/activity-controlled environment. The regimens consisted of a total of 80 mEq of potassium in three equally divided doses of elixir every 6 hr and a single 80-mEq dose using four 20-mEq sustained-release (SR) tablets. The mean time to maximum rate of potassium urinary excretion was 2.2 hr for the first elixir dose and 5.5 hr after the SR tablet (P < 0.01), thereby supporting the prolonged-release properties of this formulation. After correction for baseline urinary potassium excretion, the mean total 24-hr urinary potassium excretion was 42.18 mEq for the elixir and 40.41 mEq for the SR tablet. The results indicate that the absorption pattern from the SR tablet is equal to three doses of KC1 elixir dosed 6 hr apart. 相似文献
6.
David G Hicks Brian J Yoder Sarah Short Shannon Tarr Nichole Prescott Joseph P Crowe Andrea E Dawson G Thomas Budd Steven Sizemore Muzaffer Cicek Toni K Choueiri Raymond R Tubbs Daniel Gaile Norma Nowak Mary Ann Accavitti-Loper Andra R Frost Danny R Welch Graham Casey 《Clinical cancer research》2006,12(22):6702-6708
PURPOSE: This study aims to determine the effect of loss of breast cancer metastasis suppressor 1 (BRMS1) protein expression on disease-free survival in breast cancer patients stratified by estrogen receptor (ER), progesterone receptor (PR), or HER2 status, and to determine whether loss of BRMS1 protein expression correlated with genomic copy number changes. EXPERIMENTAL DESIGN: A tissue microarray immunohistochemical analysis was done on tumors of 238 newly diagnosed breast cancer patients who underwent surgery at the Cleveland Clinic between January 1, 1995 and December 31, 1996, and a comparison was made with 5-year clinical follow-up data. Genomic copy number changes were determined by array-based comparative genomic hybridization in 47 breast cancer cases from this population and compared with BRMS1 staining. RESULTS: BRMS1 protein expression was lost in nearly 25% of cases. Patients with tumors that were PR negative (P=0.006) or HER2 positive (P=0.039) and <50 years old at diagnosis (P=0.02) were more likely to be BRMS1 negative. No overall correlation between BRMS1 staining and disease-free survival was observed. A significant correlation, however, was seen between loss of BRMS1 protein expression and reduced disease-free survival when stratified by either loss of ER (P=0.008) or PR (P=0.029) or HER2 overexpression (P=0.026). Overall, there was poor correlation between BRMS1 protein staining and copy number status. CONCLUSIONS: These data suggest a mechanistic relationship between BRMS1 expression, hormone receptor status, and HER2 growth factor. BRMS1 staining could potentially be used in patient stratification in conjunction with other prognostic markers. Further, mechanisms other than genomic deletion account for loss of BRMS1 gene expression in breast tumors. 相似文献
7.
Jaime Guevara-Aguirre Arlan L Rosenbloom Marco Guevara-Aguirre Kemal Yariz Jeanette Saavedra Lisa Baumbach Jonathan Shuster 《Growth hormone & IGF research》2007,17(3):261-264
CONTEXT & OBJECTIVE: The Ecuadorian GH receptor deficiency (GHRD)/Laron syndrome population is the only large cohort with a single GHR mutation (E180 splice), permitting identification of numerous carrier and noncarrier first-degree relatives, to ascertain effects of heterozygosity on GH-dependent IGF-I and IGFBP-3 concentrations and on growth. DESIGN: First-degree relatives (n=212) of GHRD patients had specimens taken for IGF-I, IGFBP-3, and GHR genotyping. Normal statured (n=40) and short statured (n=40) unrelated controls had measurement of IGF-I, IGFBP-3, and stature. RESULTS: There were no significant differences between heterozygous and homozygous normal relatives in IGF-I or IGFBP-3 standard deviation scores (SDS). Heterozygous relatives had lower mean height SDS than did homozygous normals, but with extensive overlap between genotype groups in both child and adult relatives. Height SDS in general did not relate to IGF-I or IGFBP-3 concentrations. CONCLUSIONS: GH-dependent IGF-I and IGFBP-3 secretion is not affected by heterozygosity for the E180 splice mutation that causes GHRD/Laron syndrome in the Ecuadorian population. Heterozygosity is associated with reduction in mean statural SDS, but this is not sufficient to be clinically important and not mediated through measurable differences in circulating IGF-I or IGFBP-3 related to genotype. 相似文献
8.
Purpose: To illuminate the history of nurses' participation in institution-building in the early 1900s, using the Baby Hospital in Oakland, California (now called Children's Hospital Oakland) as a case.
Design: Historical research using a framework of women's history theory focused on the women who founded Oakland's Baby Hospital, 1910–1930.
Method: Data collection included studying original sources, archival material, and interviews. Data evaluation included external criticism for authenticity and genuineness, and internal criticism for accuracy and bias.
Findings: In 1912, nurse Bertha Wright and social worker Mabel Weed, with a circle of community women, including Jessica Peixotto and Jean Howard McDuffie, established the Baby Hospital. Their activism included home visits, education, research, publications, political lobbying, and state policy and program development. At the center of this activity, was the lifelong commitment of Wright and Weed, who created new definitions of family. With social changes in the late 1920s, the male Board of Directors seized control of the hospital, and relegated women to auxiliary roles.
Conclusions: Health and social issues of the United States at the turn of the century are still problematic as a new century approaches and pertain to maternal-child health, foster care, and immigration. Feminists, including nurses, have played a central role in creating solutions. Knowledge of some of their incredible effort has been lost, particularly nursing's history in the western United States. 相似文献
Design: Historical research using a framework of women's history theory focused on the women who founded Oakland's Baby Hospital, 1910–1930.
Method: Data collection included studying original sources, archival material, and interviews. Data evaluation included external criticism for authenticity and genuineness, and internal criticism for accuracy and bias.
Findings: In 1912, nurse Bertha Wright and social worker Mabel Weed, with a circle of community women, including Jessica Peixotto and Jean Howard McDuffie, established the Baby Hospital. Their activism included home visits, education, research, publications, political lobbying, and state policy and program development. At the center of this activity, was the lifelong commitment of Wright and Weed, who created new definitions of family. With social changes in the late 1920s, the male Board of Directors seized control of the hospital, and relegated women to auxiliary roles.
Conclusions: Health and social issues of the United States at the turn of the century are still problematic as a new century approaches and pertain to maternal-child health, foster care, and immigration. Feminists, including nurses, have played a central role in creating solutions. Knowledge of some of their incredible effort has been lost, particularly nursing's history in the western United States. 相似文献
9.
Jeanette Ward Rob Sanson–Fisher 《Australian and New Zealand journal of public health》1997,21(3):335-336
Abstract: Evaluation of strategies to improve opportunistic recruitment via general practice of women overdue for a cervical smear requires an accurate behavioural measure. As part of an experimental trial to evaluate the effect of a postgraduate workshop on preventive care, we conducted this methodological study to determine the accuracy of women's recall of an opportunistic discussion about cervical screening, by comparing it against audiotapes ( n = 524). Taking the taped evidence of the trainee's verbal behaviour as the gold standard, sensitivity was 85 per cent (95 per cent confidence interval (CI) 73.1 to 92.0 per cent) and specificity was 78 per cent (CI 73.9 to 81.6 per cent). Given the low rate of opportunistic recruitment by trainees in the main study, only one–third of positive recollections by women of an opportunistic discussion about cervical screening were correct. Until other measures have been validated, women's recall may continue to be used to measure general practitioners' behaviour, but an appreciation of likely bias is recommended. 相似文献
10.
Evidence that [3H]-alpha,beta-methylene ATP may label an endothelial-derived cell line 5'-nucleotidase with high affinity. 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《British journal of pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. D. Michel N. M. Chau T. P. Fan E. E. Frost P. P. Humphrey 《British journal of pharmacology》1995,115(5):767-774
1. In membranes prepared from a permanent cell line of endothelial origin (WEC cells), [3H]-alpha, beta-methylene ATP ([3H]-alpha, beta-meATP) labelled high (pKd = 9.5; Bmax = 3.75 pmol mg-1 protein) and low (pKd = 7.2; Bmax = 23.3 pmol mg-1 protein) affinity binding sites. The high affinity [3H]-alpha, beta-meATP binding sites in the WEC cell membranes could be selectively labelled with a low concentration of the radioligand (1 nM). In competition studies performed at a radioligand concentration of 1 nM, 88.6% of the sites possessed high affinity (pIC50 = 8.26) for alpha, beta-meATP. 2. The high affinity [3H]-alpha, beta-meATP binding sites appeared heterogeneous since in competition studies a number of nucleotide analogues (alpha, beta-meADP, ATP, ADP, AMP, GTP, GppNHp, GMP) and adenosine identified two populations of the sites labelled by 1 nM [3H]-alpha, beta-meATP. The proportion of sites with high affinity for these compounds was found to vary between 42 and 69%. 3. Approximately 60-69% of the binding sites labelled with 1 nM [3H]-alpha, beta-meATP possessed high affinity for alpha, beta-meADP (pIC50 = 8.87), AMP (pIC50 = 7.12), GMP (pIC50 = 7.34), UTP (pIC50 = 6.12), GTP (pIC50 = 7.59), GppNHp (pIC50 = 7.35) and adenosine (pIC50 = 5.45).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献