全文获取类型
收费全文 | 3502篇 |
免费 | 164篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 81篇 |
儿科学 | 78篇 |
妇产科学 | 66篇 |
基础医学 | 378篇 |
口腔科学 | 69篇 |
临床医学 | 248篇 |
内科学 | 826篇 |
皮肤病学 | 25篇 |
神经病学 | 357篇 |
特种医学 | 121篇 |
外科学 | 712篇 |
综合类 | 10篇 |
预防医学 | 166篇 |
眼科学 | 20篇 |
药学 | 133篇 |
中国医学 | 2篇 |
肿瘤学 | 406篇 |
出版年
2023年 | 20篇 |
2022年 | 47篇 |
2021年 | 113篇 |
2020年 | 72篇 |
2019年 | 99篇 |
2018年 | 111篇 |
2017年 | 95篇 |
2016年 | 88篇 |
2015年 | 112篇 |
2014年 | 127篇 |
2013年 | 195篇 |
2012年 | 254篇 |
2011年 | 226篇 |
2010年 | 149篇 |
2009年 | 155篇 |
2008年 | 230篇 |
2007年 | 204篇 |
2006年 | 211篇 |
2005年 | 215篇 |
2004年 | 196篇 |
2003年 | 171篇 |
2002年 | 141篇 |
2001年 | 31篇 |
2000年 | 19篇 |
1999年 | 23篇 |
1998年 | 32篇 |
1997年 | 28篇 |
1996年 | 28篇 |
1995年 | 12篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 23篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 21篇 |
1986年 | 18篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 14篇 |
1979年 | 17篇 |
1977年 | 7篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1967年 | 4篇 |
1966年 | 8篇 |
排序方式: 共有3698条查询结果,搜索用时 15 毫秒
1.
Chouraqui Jean-Pierre Tavoularis Gabriel Simeoni Umberto Ferry Constance Turck Dominique 《European journal of nutrition》2020,59(1):67-80
European Journal of Nutrition - The French Nutri-Bébé 2013 study aimed to assess the nutritional intake of infants and young children in comparison with the recommendations of the 2013... 相似文献
2.
3.
4.
Marco Maruzzo Umberto Basso Eugenio Borsatti Laura Evangelista Filippo Alongi Orazio Caffo Francesca Maines Sara Galuppo Rocco De Vivo Fable Zustovich Dario Palleschi Andrea Zivi Teodoro Sava Mariella Sorarù Roberto Iacovelli Maurizio Nicodemo Susanne Baier Lucia Fratino Vittorina Zagonel 《Clinical genitourinary cancer》2019,17(1):e187-e194
Background
Radium 223 was introduced for metastatic castration-resistant prostate cancer based on the results of a randomized controlled trial showing risk reduction for death and skeletal events. Our aim was to evaluate the outcome of patients receiving radium 223 in a real-world setting.Patients and Methods
We conducted a multicenter retrospective analysis in the Triveneto region of Italy.Results
One hundred fifty-eight patients received radium 223 in our region. After a median follow-up of 9.5 months, 75 patients died. The median overall survival (OS) was 14.2 months, and the median progression-free survival (PFS) was 6.2 months. Seventy-one (45%) patients achieved progression as best response. Thirty-seven (23%) patients stopped the treatment early because of progression. Eastern Cooperative Oncology Group performance status was prognostic for OS (18.4 vs. 12.3 vs. 7.5 months; 0 vs. 1, P = .0062; 0 vs. 2, P = .0002), whereas previous prostatectomy or docetaxel exposure were not. A neutrophil to lymphocytes ratio ≥ 3 significantly impacted OS (18.1 vs. 9.7 months; P < .001) and slightly impacted PFS (6.6 vs. 5.6 months; P = .05). Patients with a baseline alkaline phosphatase (ALP) value ≥ 220 U/L had worse OS and PFS (24.1 vs. 10.5 months; 7.2 vs. 5.5 months; P < .001). Patients with changes in ALP value achieved better OS (P = .029) and PFS (P = .002). There was no difference according to the line of therapy (0 vs. ≥ 1; P = .490). The main grade 3/4 toxicities were anemia, asthenia, and thrombocytopenia.Conclusion
This large real-world report confirms comparable OS and PFS data when compared with the pivotal study, as well as the predictive role of ALP and neutrophil to lymphocytes ratio. The definition of the optimal position of radium 223 in the treatment of metastatic castration-resistant prostate cancer has still to be defined. 相似文献5.
6.
Stefano Di Domenico Giulio Bovio Maximiliano Gelli Ferruccio Ravazzoni Enzo Andorno Damiano Cottalasso Umberto Valente 《BMC surgery》2007,7(1):18
Background
Liver transplantation in presence of diffuse portal vein thrombosis is possible by using caval blood as portal inflow, through cavo-portal transposition. However, clinical results are heterogeneous and experimental studies are needed, but similar hemodynamic conditions are difficult to obtain, especially in small animals. Herein we describe a new simple model of cavo-portal transposition in rat. 相似文献7.
C. S. Peretti J. M. Danion F. Kauffmann-Muller D. Grangé A. Patat P. Rosenzweig 《Psychopharmacology》1997,129(4):329-338
Buprenorphine is a mu opioid partial agonist currently used as an analgesic, and being developed for the treatment of opioid
dependence. The purpose of this study was to determine the abuse liability of parenteral buprenorphine in volunteers maintained
on daily sublingual (SL) buprenorphine (8 mg). In a residential laboratory, eight volunteers underwent pharmacologic challenges
two times per week. Medication challenges were 16 h after the daily dose of buprenorphine, and consisted of double-blind IM
injections of buprenorphine (4, 8, 16 mg), the prototypic mu opioid agonist hydromorphone (9 and 18 mg), or saline. Assessments
consisted of physiologic monitoring, subjects’ self-reports, and a trained observer’s ratings of drug effects, and were collected
for 0.5 h before and 2.0 h following injection. Supplemental doses of IM buprenorphine produced opioid agonist-like effects,
indicating some abuse potential of parenteral buprenorphine in buprenorphine-maintained patients. There was incomplete cross-tolerance
to the effects of hydromorphone, suggesting that higher maintenance doses of buprenorphine may be needed to maximize clinical
efficacy. However, there was a lack of graded dose-effects for hydromorphone, suggesting that buprenorphine’s combination
of partial agonist effects and high affinity for opioid receptors may limit the magnitude of effects of supplemental full
agonists. Finally, participants tolerated cumulative doses of maintenance buprenorphine plus challenge buprenorphine without
adverse effects, suggesting higher doses of buprenorphine can be safely administered to opioid dependent patients.
Received: 22 February 1996/Final version: 23 August 1996 相似文献
8.
Franco Rilke M. D. F. R. C. Umberto Veronesi M. D. Alberto Luini M. D. Cristina Brambilla M. D. Viviana Galimberti M. D. Stefano Zurrida M. D. Silvana Pilotti M. D. M. I. A. C. Silvana Di Palma M. D. Roberto Zucali M. D. Laura Lozza M. D. 《The breast journal》1996,2(3):176-180
Abstract: Breast conservation surgery is an effective and safe treatment for many breast carcinomas. It may be possible to further limit the extent of resection (or expand the indication for breast conservation) by the application of preoperative chemotherapy and radiotherapy. We explored the feasibility of this in a pilot study.
Seventy-three patients (mean age 48, 63% premenopausal) with confirmed breast cancer, less than 2.5 cm, received chemotherapy (Group A) or chemotherapy plus radiotherapy (Group B) prior to limited resection (tumorectomy). Axillary dissection was always performed. Results: In 6/31 (19%) Group A and 17/42 (40%) Group B patients the tumor was not palpable after preoperative treatment, with complete pathological remission in 1 and 3 cases respectively. Histologic grading, mitosis, cellular alteration, and cellularity evaluations indicated a consistently greater therapeutic effect with chemoradiotherapy than with chemotherapy alone.
In conclusion, radiotherapy appears useful in the preoperative treatment of breast cancer and its use in association with various drug combinations should be further explored. 相似文献
Seventy-three patients (mean age 48, 63% premenopausal) with confirmed breast cancer, less than 2.5 cm, received chemotherapy (Group A) or chemotherapy plus radiotherapy (Group B) prior to limited resection (tumorectomy). Axillary dissection was always performed. Results: In 6/31 (19%) Group A and 17/42 (40%) Group B patients the tumor was not palpable after preoperative treatment, with complete pathological remission in 1 and 3 cases respectively. Histologic grading, mitosis, cellular alteration, and cellularity evaluations indicated a consistently greater therapeutic effect with chemoradiotherapy than with chemotherapy alone.
In conclusion, radiotherapy appears useful in the preoperative treatment of breast cancer and its use in association with various drug combinations should be further explored. 相似文献
9.
A. I. Fabra De Peretti G. B. Mori De Moro N. E. Ghittoni A. M. Evangelista De Duffard R. O. Duffard 《Environmental toxicology》1987,2(2):217-228
The effects of 2,4-Dichlorophenoxyacetic acid on the growth rate, chemical composition, 14C-2,4-dichlorophenoxyacetic acid and 45Ca2+ uptake by Rhizobium sp. M 4 able to nodulate Arachis hypogaea were determined. Cellular growth was diminished by the presence of 10?3 M 2,4-dichlorophenoxyacetic acid in the medium. Alterations in cellular chemical composition, in 14C-2,4-dichlorophenoxyacetic acid and in 45Ca2+ uptake were found. 相似文献
10.
Epidermal growth factor directly stimulates steroidogenesis in primary cultures of porcine Leydig cells: actions and sites of action 总被引:7,自引:0,他引:7
The actions and the mechanisms of action of epidermal growth factor (EGF) in testicular steroidogenesis were investigated using a model of primary culture of purified porcine Leydig cells from immature intact animals. EGF decreased (1.7-fold) human CG (hCG)-induced dehydroepiandrosterone (DHEA) accumulation in the medium whereas it enhanced (2.5-fold) that of testosterone. The maximal and half-maximal effects on both DHEA and testosterone secretions were observed at similar concentrations which were, respectively, 3 (5 x 10(-10) M) and 0.7 (11 x 10(-11) M) ng/ml EGF, after 72-h treatment. EGF effect on DHEA and testosterone secretion was similarly observed whether the cells were acutely (3 h) stimulated with hCG (1 ng/ml) or with 8-bromo-cAMP (10(-3) M). To further localize the steroidogenic biochemical steps affected by EGF, the growth factor action on steroidogenic enzyme activities was investigated. EGF increased delta 5 steroid intermediate (i.e. pregnenolone and DHEA) formation [evaluated in the presence of 10(-5) M of WIN 24540, an inhibitor of 3 beta-hydroxysteroid dehydrogenase/iosomerase (3 beta-HSDI) activity]. However, this stimulation was observed in cells when acutely (3 h) stimulated with hCG (0.01-1 ng/ml) but not when incubated with 22R-hydroxycholesterol (0.01-10 micrograms/ml). Such findings indicate that EGF did not affect cholesterol side chain cleavage cytochrome P450 activity but probably increased cholesterol substrate availability for this enzyme in the inner mitochondria. Moreover, EGF significantly (P less than 0.001) increased delta 5 steroid intermediate (i.e. pregnenolone and DHEA) but not delta 4 steroid intermediate (i.e. progesterone and androstenedione) conversion into testosterone, indicating that EGF enhances 3 beta-HSDI activity. Such effects of EGF are directly exerted on Leydig cells since EGF receptors (Kd = 16 x 10(-11) M) are present in primary cultures of purified porcine Leydig cells. Together, the present findings show that in Leydig cells from intact animals, EGF enhances the gonadotropin action on testosterone formation through an increase in the availability of cholesterol substrate in the mitochondria as well as an increase in the activity of 3 beta-HSDI. 相似文献