全文获取类型
收费全文 | 13276篇 |
免费 | 971篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 568篇 |
妇产科学 | 373篇 |
基础医学 | 1852篇 |
口腔科学 | 109篇 |
临床医学 | 2028篇 |
内科学 | 2395篇 |
皮肤病学 | 120篇 |
神经病学 | 1181篇 |
特种医学 | 252篇 |
外国民族医学 | 1篇 |
外科学 | 1292篇 |
综合类 | 188篇 |
一般理论 | 14篇 |
预防医学 | 1738篇 |
眼科学 | 141篇 |
药学 | 665篇 |
中国医学 | 13篇 |
肿瘤学 | 1246篇 |
出版年
2024年 | 14篇 |
2023年 | 95篇 |
2022年 | 124篇 |
2021年 | 313篇 |
2020年 | 245篇 |
2019年 | 390篇 |
2018年 | 378篇 |
2017年 | 301篇 |
2016年 | 324篇 |
2015年 | 322篇 |
2014年 | 451篇 |
2013年 | 723篇 |
2012年 | 1050篇 |
2011年 | 1111篇 |
2010年 | 612篇 |
2009年 | 563篇 |
2008年 | 946篇 |
2007年 | 976篇 |
2006年 | 895篇 |
2005年 | 880篇 |
2004年 | 789篇 |
2003年 | 684篇 |
2002年 | 682篇 |
2001年 | 127篇 |
2000年 | 123篇 |
1999年 | 147篇 |
1998年 | 118篇 |
1997年 | 109篇 |
1996年 | 83篇 |
1995年 | 101篇 |
1994年 | 63篇 |
1993年 | 57篇 |
1992年 | 43篇 |
1991年 | 40篇 |
1990年 | 37篇 |
1989年 | 55篇 |
1988年 | 33篇 |
1987年 | 36篇 |
1986年 | 21篇 |
1985年 | 19篇 |
1984年 | 27篇 |
1983年 | 24篇 |
1982年 | 27篇 |
1981年 | 24篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1972年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
41.
42.
Amy Farabaugh David Mischoulon Maurizio Fava Wendy Guyker Jonathan Alpert 《Annals of clinical psychiatry》2004,16(4):217-224
BACKGROUND: Research studies have focused attention on the importance of the comorbidity of personality disorders and depression. METHODS: The present review examines seven potential explanations for the overlap to clarify the nature of the relationship, if any, between depression and personality disorder diagnoses. RESULTS: There may be many explanations for the potential overlap of personality disorders (PD) and major depressive disorder (MDD). For example, the distinction between states and traits may not be as clear and definitive as suggested in the DSM-IV. In some cases, depression may influence personality pathology, and may even lead to personality disorders. In other cases, personality disorders may lead to MDD. CONCLUSION: Further research may clarify the nature of the relationship, if any, between depression and personality disorder diagnoses, as well as the relationship between comorbidity and treatment response. 相似文献
43.
Carol A. Sawka Kathleen I. Pritchard Wendy Shelley Gerrit DeBoer Alexander H.G. Paterson J. William Meakin Donald J.A. Sutherland 《Breast cancer research and treatment》1997,43(3):211-215
Background: The outcome of breast cancer is usuallydetermined by multiple factors. Serum tumor necrosis factoralpha concentration has been found to be increasedin the circulation of patients with malignancy. Thisstudy was designed with the aim to investigateany correlation between the serum tumor necrosis factoralpha and the clinicopathological fetures and furthermore evaluatethe prognostic significance of serum tumor necrosis factoralpha concentration in breast cancer. Methods: Forty consecutivepatients with invasive breast cancer undergoing modified radicalmastectomy were prospectively included and evaluated. Venous bloodsamples were collected before the surgery. Sera wereobtained by centrifugation, and stored at – 70°C until assayed. The control group consisted 30healthy, age-matched subjects. Serum concentrations of tumor necrosisfactor alpha were measured by the quantitative sandwichenzyme immunoassay technique. The data on tumor size,age, estrogen receptor status, lymph node status andTNM staging were reviewed and recorded.Results: The mean value of serum tumor necrosis factor alphain patients with invasive breast cancer was 1.47± 0.58 pg/ml and that of the controlgroup was 0.98 ± 0.37 pg/ml, and thedifference was significant (P < 0.01). With univariableanalysis, patients with maximum tumor size of 5cm or larger (P=0.03), more advancedTNM staging (P < 0.01); and more advancedlymph node status (P < 0.01) were shownto have significantly higher serum concentrations of tumornecrosis factor alpha. However, with multivariable analysis, TNMstaging appeared as the only independent factor (P< 0.01) predicting the significant, higher serum concentrationsof tumor necrosis factor alpha. Conclusion: Preoperative evaluationof serum tumor necrosis factor alpha concentrations maybe a valuable parameter for reflecting the severityof staging for invasive breast cancer. 相似文献
44.
45.
M Tyshkov S Berezin S Jayabose H Bostwick M Glassman L Newman 《Journal of pediatric gastroenterology and nutrition》1991,13(2):197-200
A 12-year-old girl is described who developed rectal bleeding 5 months after being diagnosed as having a Coombs-positive hemolytic anemia. Colonoscopy showed that the rectal bleeding was due to ulcerative proctitis. This is the first case report of Coombs-positive hemolytic anemia preceding the onset of ulcerative proctitis in a child. 相似文献
46.
Vagus Nerve Stimulation Induces a Sustained Anticonvulsant Effect 总被引:17,自引:11,他引:6
Summary: Purpose: Stimulation of the vagus nerve can effectively abort several types of experimentally induced seizures in animals when administered near the time of seizure onset. Indirect evidence from human trials and animal studies suggests that the anticonvulsant effects of vagus nerve stimulation (VNS) extend beyond the duration of stimulation. We used the pentylenetetrazol model to determine whether VNS exerts a persistent anticonvulsant effect.
Methods: VNS (1 mA, 30 Hz, 500 μs pulse width) was administered continuously for 0, 1, or 60 min, or intermittently (30 s on, 5 min off) for 60 min, to awake and freely moving animals. After the end of stimulation, pentylenetetrazol (50 mg/kg i.p.) was administered to induce seizures. Time-course studies were also performed, consisting of 60 min of VNS followed by pentylenetetrazol injection after 0, 3-, 5-, and 10-min intervals.
Results: The greatest anticonvulsant effect occurred after 60 min of continuous VNS, which prevented convulsions in four of 12 rats and reduced significantly seizure duration, the total number of seizures, and number of tonic seizures. Intermittent VNS was less effective than continuous stimulation for 60 min, but more effective than that for 1 min. The anticonvulsant effect declined in a time-dependent fashion after discontinuation of VNS, with return to nonstimulated control values by 10 min.
Conclusions: The results of this study verify a persistent VNS-induced anticonvulsant effect and indicate that its efficacy is dependent on the cumulative stimulus duration. 相似文献
Methods: VNS (1 mA, 30 Hz, 500 μs pulse width) was administered continuously for 0, 1, or 60 min, or intermittently (30 s on, 5 min off) for 60 min, to awake and freely moving animals. After the end of stimulation, pentylenetetrazol (50 mg/kg i.p.) was administered to induce seizures. Time-course studies were also performed, consisting of 60 min of VNS followed by pentylenetetrazol injection after 0, 3-, 5-, and 10-min intervals.
Results: The greatest anticonvulsant effect occurred after 60 min of continuous VNS, which prevented convulsions in four of 12 rats and reduced significantly seizure duration, the total number of seizures, and number of tonic seizures. Intermittent VNS was less effective than continuous stimulation for 60 min, but more effective than that for 1 min. The anticonvulsant effect declined in a time-dependent fashion after discontinuation of VNS, with return to nonstimulated control values by 10 min.
Conclusions: The results of this study verify a persistent VNS-induced anticonvulsant effect and indicate that its efficacy is dependent on the cumulative stimulus duration. 相似文献
47.
Reflective inquiry in nursing practice or 'revealing images' 总被引:1,自引:0,他引:1
Penelope Cash Jenny Brooker Wendy Penney Janet Reinbold Laurence Strangio 《Nursing inquiry》1997,4(4):246-256
Reflective inquiry in nursing practice or 'revealing images' Nurses live and work in complex practice worlds; worlds of shrinking resources and expanding needs. Reflection through journaling offers unique opportunities to gain insight into practice. What might we learn from one's journal? A reflective journal can be a source of interplay between the self as written and the self as other. Likewise, the journal may act to situate ourselves in practice, while at the same time enabling us to illuminate how and in what ways our understandings have become distorted. The extent to which one's journal is educative depends upon the manner in which one chooses to use it as a transformative tool, a tool that might well be described as a process of healing and enlightenment. In order to illustrate the reflexive nature of journaling, this paper is presented as a play reading, where a conversation about practice stories between the different aspects of the nurse's self is depicted. In adopting a play reading, an alternative pedagogical tool is used to illustrate different methodologies exemplifying the emergence of how and in what ways we develop and reconstruct our understanding in nursing. 相似文献
48.
49.
Wendy J Sturtz Kathleen H Leef Amy B Mackley Shailja Sharma Teodoro Bottiglieri David A Paul 《BMC pediatrics》2007,7(1):38
Background
The purpose of this study was to characterize total homocysteine (tHcy) levels at birth in preterm and term infants and identify associations with intraventricular hemorrhage (IVH) and other neonatal outcomes such as mortality, sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and thrombocytopenia. 相似文献50.
Paul Fernyhough Wendy J. Brewster Karin Fernandes Lara T. Diemel David R. Tomlinson 《Brain research》1998,802(1-2)
In rats with streptozotocin-induced diabetes, we measured increased (by 61%; P<0.05) mRNA for nerve growth factor (NGF) in the iris together with increased (by 82%; P<0.05) mRNA for preprotachykinin (the substance P precursor) in the trigeminal ganglion, suggesting that increased NGF was driving increased substance P gene expression. In other diabetic rats, these changes were prevented by treatment with either an antioxidant (butylated hydroxytoluene; 1% by diet) or an aldose reductase inhibitor (ARI) (sorbinil; 25 mg/kg/day p.o.) and the sorbinil treatment was associated with significant inhibition of polyol pathway intermediates in both lens and sciatic nerve. This suggests that polyol pathway activity in the lens may translate to oxidative stress-driving stimulation of NGF gene expression in the iris. The change is selective for NGF, because expression of the analogous neurotrophin, neurotrophin-3 (NT-3), was unaltered in the same irises. These changes suggest that oxidative stress and/or inflammation can drive up NGF expression in diabetes—a mechanism that might participate in iritis. 相似文献