全文获取类型
收费全文 | 42222篇 |
免费 | 1337篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 467篇 |
儿科学 | 1468篇 |
妇产科学 | 975篇 |
基础医学 | 4936篇 |
口腔科学 | 505篇 |
临床医学 | 6654篇 |
内科学 | 7170篇 |
皮肤病学 | 428篇 |
神经病学 | 3991篇 |
特种医学 | 861篇 |
外国民族医学 | 1篇 |
外科学 | 3824篇 |
综合类 | 398篇 |
一般理论 | 50篇 |
预防医学 | 5637篇 |
眼科学 | 427篇 |
药学 | 2537篇 |
1篇 | |
中国医学 | 45篇 |
肿瘤学 | 3258篇 |
出版年
2024年 | 241篇 |
2023年 | 348篇 |
2022年 | 474篇 |
2021年 | 902篇 |
2020年 | 657篇 |
2019年 | 1019篇 |
2018年 | 1128篇 |
2017年 | 834篇 |
2016年 | 907篇 |
2015年 | 1013篇 |
2014年 | 1408篇 |
2013年 | 2163篇 |
2012年 | 3122篇 |
2011年 | 3332篇 |
2010年 | 1765篇 |
2009年 | 1618篇 |
2008年 | 2865篇 |
2007年 | 2910篇 |
2006年 | 2837篇 |
2005年 | 2834篇 |
2004年 | 2606篇 |
2003年 | 2313篇 |
2002年 | 2232篇 |
2001年 | 265篇 |
2000年 | 215篇 |
1999年 | 287篇 |
1998年 | 453篇 |
1997年 | 358篇 |
1996年 | 270篇 |
1995年 | 229篇 |
1994年 | 226篇 |
1993年 | 216篇 |
1992年 | 140篇 |
1991年 | 124篇 |
1990年 | 103篇 |
1989年 | 111篇 |
1988年 | 96篇 |
1987年 | 92篇 |
1986年 | 94篇 |
1985年 | 93篇 |
1984年 | 108篇 |
1983年 | 87篇 |
1982年 | 99篇 |
1981年 | 103篇 |
1980年 | 81篇 |
1979年 | 47篇 |
1978年 | 33篇 |
1977年 | 44篇 |
1976年 | 22篇 |
1975年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
David L O'Riordan Kevin B Lunde Johann Urschitz Karen Glanz 《Cancer epidemiology, biomarkers & prevention》2005,14(3):722-726
OBJECTIVES: To study whether a noninvasive swabbing technique can detect sunscreen use for up to 6 hours, and whether the technique can detect reapplication of sunscreen. METHODS: Thirty volunteer office workers were randomly assigned to have one of a variety of sunscreens applied using recommended application techniques, and half were randomly assigned to have sunscreen reapplied after 3 hours. Alcohol-based swabs were used to obtain a sample from participants' arm at 20 minutes, and hourly from 1 to 6 hours post-application. Absorption readings were analyzed using an UV-visible spectrophotometer. RESULTS: The swabbing technique was consistently able to distinguish the sunscreen from control swabs for up to 6 hours. The absorption readings between 20 minutes and 6 hours were significantly higher than control swabs. There were no differences between the group that had sunscreen reapplied and the group that did not. CONCLUSION: The sunscreen swabbing technique is an effective noninvasive method for detecting a variety of sunscreen products in adults over a 6-hour period. No differences in absorption readings were found with sunscreen reapplication. This procedure will be a useful adjunct to other objective measures of sun protection and UV radiation exposure, resulting in a more accurate picture of the sun protection habits of individuals. 相似文献
102.
vom Saal FS Akingbemi BT Belcher SM Birnbaum LS Crain DA Eriksen M Farabollini F Guillette LJ Hauser R Heindel JJ Ho SM Hunt PA Iguchi T Jobling S Kanno J Keri RA Knudsen KE Laufer H LeBlanc GA Marcus M McLachlan JA Myers JP Nadal A Newbold RR Olea N Prins GS Richter CA Rubin BS Sonnenschein C Soto AM Talsness CE Vandenbergh JG Vandenberg LN Walser-Kuntz DR Watson CS Welshons WV Wetherill Y Zoeller RT 《Reproductive toxicology (Elmsford, N.Y.)》2007,24(2):131-138
103.
Davis AJ Gelmon KA Siu LL Moore MJ Britten CD Mistry N Klamut H D'Aloisio S MacLean M Wainman N Ayers D Firby P Besterman JM Reid GK Eisenhauer EA 《Investigational new drugs》2003,21(1):85-97
Purpose: MG98 is a second generation phosphorothioate antisense oligodeoxynucleotide which is a highly specific inhibitor of translation of the mRNA for human DNA MeTase I (DNMT 1). This phase I study examined the toxicity and pharmacologic profile of MG98 administered as a continuous 21-day intravenous infusion every 4 weeks. Patients and methods: Fourteen patients with solid cancers received a total of 25 cycles of MG98 at doses ranging from 40 to 240 mg/m2/day. Steady-state concentrations of MG98 were measured as were several pharmacodynamic assessments including mRNA of the target gene, DNMT1, in PBMC. In addition, other potential surrogate markers of drug effects were explored, including hemoglobin F, Vimentin and GADD45. Results: Dose limiting effects were drug-related reversible transaminase elevation and fatigue seen at doses of 240, 200 and 160 mg/m2/day. The dose level of 80 mg/m2/day was felt to be safe and tolerable when delivered on this schedule. No evidence of antitumor activity was observed. Although pharmacokinetic analysis revealed that at the higher dose levels, mean Css values of MG98 were approximately 10-fold times the IC50 values associated with target inhibition in vitro, the extent of MG98 penetration into target tumors in this trial was not determined. No consistent, dose-related changes in correlative markers including DNMT1 mRNA, hemoglobin F, Vimentin and GADD45, were observed. Conclusions: This schedule of MG98 given as a 21-day continuous intravenous infusion every 4 weeks was poorly tolerated in the highest doses; therefore, further disease-site specific evaluation of the efficacy of this agent will utilize a more favorable, intermittent dosing schedule. Pharmacodynamic evaluations undertaken in an attempt to explore and validate the biological mechanisms of MG98 did not show dose-related effects. 相似文献
104.
Lacour RA Daniels MS Westin SN Meyer LA Burke CC Burns KA Kurian S Webb NF Pustilnik TB Lu KH 《Gynecologic oncology》2008,111(1):132-136
ObjectivesFew women with ovarian cancer undergo genetic testing for the Breast and Ovarian Cancer susceptibility genes, BRCA1 and BRCA2. With the prospect of BRCA-directed therapeutics, we investigated ovarian cancer patients' knowledge and willingness to undergo genetic testing.MethodsAll ovarian cancer patients seen in the Gynecology Center of a cancer center and a private clinic were asked to complete an anonymous questionnaire regarding knowledge and willingness to undergo BRCA testing. Women who had prior genetic testing were asked not to participate. Data was analyzed using Fisher's exact test.ResultsTwo-hundred and thirty seven ovarian cancer patients voluntarily completed the questionnaire. Fifty-five percent (131/237) of participants had not heard of BRCA testing. Of Caucasian respondents, 51% were unaware of BRCA testing, compared to 70% of Hispanic and 88% of African American respondents (p = 0.008). Awareness was correlated with education (p < 0.001). Eighty-nine percent of participants were willing to be tested if it would directly affect their therapy and 86.9% would be tested to benefit their family. Seventy-four percent of patients would pay 20% of the cost of testing, only 25.1% would pay in full.ConclusionsA majority of women with ovarian cancer are not aware of the availability of BRCA testing. This lack of awareness is more profound in minorities. Despite lack of knowledge, most patients would undergo testing if it would impact their care. However, cost may be a barrier. Given the willingness of patients to undergo testing and the possibility of targeted therapy, clinicians who care for these patients should work to make appropriate genetic counseling referrals. 相似文献
105.
Milam MR Sood AK King S Bassett RL Lu KH Slomovitz BM Coleman RL Ramirez PT 《Obstetrics and gynecology》2007,109(3):641-646
OBJECTIVE: To assess whether supracervical hysterectomy (SCH) is a reasonable alternative to total abdominal hysterectomy in patients with advanced ovarian cancer. METHODS: We reviewed the records of patients with advanced ovarian cancer who underwent a SCH at one institution between 1993 and 2004 and a similar cohort who underwent total abdominal hysterectomy (TAH) at the same institution during the same period. Patients without complete surgical staging done at the institution were excluded. Independent-sample t tests, Fisher exact test, and log rank tests were used for statistical analysis. RESULTS: The study included 47 patients who underwent SCH (mean age, 59.6 years) and 190 who underwent TAH. There were no significant differences between the two groups in age (P=.51), preoperative CA 125 level (P=.55), or receipt of taxane-based and platinum-based chemotherapy (P=.84). Although limited by sample size, there were no significant differences between the two groups in rates of intraoperative complications (4 of 47 in the SCH group, or 8.5%, compared with 7 of 190 in the TAH group, or 3.7%; P=.24), vaginal or cervical recurrence (5 of 47 in the SCH group, or 10.6%, compared with 22 of 190 in the TAH group, or 11.6%; P=1.00), or in progression-free survival (SCH of 1.01 years compared with TAH of 1.19 years; P=.64) or overall survival (SCH of 3.28 years compared with TAH of 3.36 years; P=.12). CONCLUSION: Supracervical hysterectomy may be a reasonable alternative to TAH in patients with advanced ovarian cancer. LEVEL OF EVIDENCE: II. 相似文献
106.
107.
The patient's pelvic structures repeatedly shifted out of place. Her physicians found a fix that helped. 相似文献
108.
109.
Stringer M Brooks PM King K Biesecker B 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》2007,36(6):624-635
New evidence has prompted changes in our national cardiopulmonary resuscitation guidelines for both neonates and adult patients. The purpose of this article is to provide an overview of the changes recommended by the American Heart Association, Academy of American Pediatrics, and the American College of Obstetrics and Gynecology. In addition, a strategy for implementing these guidelines into practice is suggested. 相似文献
110.