全文获取类型
收费全文 | 4412篇 |
免费 | 325篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 123篇 |
妇产科学 | 100篇 |
基础医学 | 614篇 |
口腔科学 | 80篇 |
临床医学 | 411篇 |
内科学 | 1006篇 |
皮肤病学 | 87篇 |
神经病学 | 437篇 |
特种医学 | 103篇 |
外科学 | 474篇 |
综合类 | 24篇 |
一般理论 | 2篇 |
预防医学 | 376篇 |
眼科学 | 110篇 |
药学 | 369篇 |
中国医学 | 12篇 |
肿瘤学 | 376篇 |
出版年
2024年 | 9篇 |
2023年 | 82篇 |
2022年 | 142篇 |
2021年 | 248篇 |
2020年 | 138篇 |
2019年 | 157篇 |
2018年 | 203篇 |
2017年 | 119篇 |
2016年 | 152篇 |
2015年 | 150篇 |
2014年 | 220篇 |
2013年 | 258篇 |
2012年 | 392篇 |
2011年 | 377篇 |
2010年 | 210篇 |
2009年 | 179篇 |
2008年 | 286篇 |
2007年 | 294篇 |
2006年 | 232篇 |
2005年 | 221篇 |
2004年 | 174篇 |
2003年 | 143篇 |
2002年 | 123篇 |
2001年 | 30篇 |
2000年 | 25篇 |
1999年 | 23篇 |
1998年 | 19篇 |
1997年 | 15篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1979年 | 13篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1971年 | 3篇 |
排序方式: 共有4776条查询结果,搜索用时 15 毫秒
61.
Jacques Lalevée Guillaume Povie Mohamad Ali Tehfe Sofia Telitel Fabrice Morlet‐Savary Bernadette Graff Jean Pierre Fouassier 《Macromolecular chemistry and physics.》2012,213(15):1618-1622
Upon demand, 1,3‐diamino‐propane‐triethylborane (DAPTB) is photolyzed in the presence of an acid generator such as a diphenyliodonium salt. Interestingly, triethylborane is released. In the presence of oxygen, ethyl radicals are generated and initiate an acrylate polymerization. This is the first example of a phototriggered production of a triethylborane usable in the photoinitiation of acrylate polymerizations. This approach is also worthwhile to overcome the oxygen inhibition for free‐radical polymerization processes. 相似文献
62.
63.
The media is a powerful societal tool for expressing expectations about how men and women should look. As a result, over the past several years, women have shown an increase in body dissatisfaction (Cash, Morrow, Hrabosky, & Perry, 2004). The present study examined the relationships between drive for thinness, self-esteem, and media influence among men and women. Two hundred ninety-four college students completed the Texas Social Behavior Inventory (Helmreich & Stapp, 1974), Sociocultural Attitudes towards Appearance Scale-3 (Thompson, van den Berg, Roehrig, Guarda, & Hienberg, 2004), self-constructed questionnaire influence of media models, and the drive for Thinness Subscale (DT) from the Eating Disorder Inventory-3 (EDI-3; (Garner, 2004)). We expected to find an association between drive for thinness and media influence and between drive for thinness and self-esteem for both men and women. Finally, we expected that the use of media, social pressures and media internalization would be predictors of drive for thinness. We found a relationship between media influence and drive for thinness. There was also a relationship between self-esteem and drive for thinness. For both men and women, media models were the primary predictor for drive for thinness. However, for women the secondary predictor was social pressures; whereas for men the secondary predictor was internalization. Such findings show the importance of examining the impact of media sources on men and women in order to entangle gender differences. 相似文献
64.
G. Garibotto A. Sofia S. Saffioti A. Bonanni I. Mannucci E.L. Parodi V. Cademartori D. Verzola 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2013
Protein-energy wasting is relatively common in renal patients treated with haemodialysis or peritoneal dialysis (PD) and is associated with worse outcome. In this article, we review the current state of our knowledge regarding the effects of PD on protein metabolism and the possible interactions between PD-induced changes in protein turnover and the uraemia-induced alterations in protein metabolism. Available evidence shows that PD induces a new state in muscle protein dynamics, which is characterized by decreased turnover rates and a reduced efficiency of protein turnover, a condition which may be harmful in stress conditions, when nutrient intake is diminished or during superimposed catabolic illnesses. There is a need to develop more effective treatments to enhance the nutritional status of PD patients. New approaches include the use of amino acid/keto acids-containing supplements combined with physical exercise, incremental doses of intraperitoneal amino acids, vitamin D and myostatin antagonism for malnourished patients refractory to standard nutritional therapy. 相似文献
65.
Anpalakan Sathasivam Luigi Garibaldi Sofia Shapiro James Godbold Robert Rapaport 《Clinical endocrinology》2010,73(3):375-381
Context Low concentrations of serum LH and/or oestradiol (E2) in girls with early physical signs of precocious puberty pose a diagnostic challenge. Objective To assess the diagnostic value of the leuprolide stimulation test in female precocious puberty. Design Retrospective Chart Review. Setting Outpatient clinic. Patients and intervention Thirty‐nine girls, 6·9 (1·4) years, with premature stage II–III breast development, with or without pubarche, underwent stimulation testing with subcutaneous leuprolide (20 μg/kg) with the following hormonal measurements in serum: FSH, LH, oestradiol at baseline; FSH and LH at 1 and 2 h; oestradiol at 24 h. Twelve girls with isolated pubarche were also tested with leuprolide. Main outcome measure A pubertal hormonal pattern was defined as at least one of the following: a baseline serum level of LH ≥ 0·3 U/l, a baseline oestradiol ≥ 37 pmol/l (10 ng/l), a stimulated (peak) LH ≥ 5·0 U/l, a stimulated oestradiol ≥ 184 pmol/l (50 ng/l) to leuprolide. The hormonal response was related to the clinical course during a period of observation of at least 6 months. Results Following leuprolide stimulation, the hormonal response was concordant with pubertal progression (n = 23) or lack thereof (n = 16) in all children. At baseline, pubertal serum concentrations of LH and/or oestradiol were associated with pubertal progression in all, while serum prepubertal LH and/or oestradiol concentrations were associated with pubertal progression in approximately 50% of the patients. Conclusions In girls with early clinical signs of precocious puberty and low serum concentrations of LH and oestradiol in random samples, the LH and oestradiol responses to leuprolide stimulation accurately predict pubertal progression. 相似文献
66.
Matthias Szabolcs Megan Keniry Laura Simpson Latarsha J. Reid Susan Koujak Sarah C. Schiff Giselle Davidian Scott Licata Sofia Gruvberger-Saal Vundavalli V.V.S. Murty Subhadra Nandula Argiris Efstratiadis Jake A. Kushner Morris F. White Ramon Parsons 《The American journal of pathology》2009,174(1):276-286
Mutations in the phosphatase and tensin homologue (PTEN)/phosphatidylinositol-3 kinase-α (PI3K) signaling pathway are frequently found in human cancer. In addition, Pten+/− mice develop tumors in multiple organs because of the activation of the PI3K signaling cascade. Because activation of PI3K signaling leads to feedback inhibition of insulin receptor substrate-2 (IRS2) expression, an upstream activator of PI3K, we therefore anticipated that IRS2 expression would be low in tumors that lack PTEN. Surprisingly, however, an elevation of IRS2 was often detected in tumor samples in which PTEN levels were compromised. To determine the potential contribution of Irs2 to tumor progression, Pten+/− mice were crossed with Irs2+/− mice. Deletion of Irs2 did not affect the initiation of neoplasia found in Pten+/− mice but suppressed cancer cell growth, proliferation, and invasion through the basement membrane. Deletion of Irs2 also attenuated the expression of Myc in prostatic intraepithelial neoplasia in Pten+/− mice. In addition, the expression levels of IRS2 and MYC were highly correlated in human prostate cancer, and IRS2 could stimulate MYC expression in cultured cells. Our findings provide evidence that the PI3K-activating adaptor Irs2 contributes to tumor progression in Pten+/− mice by stimulating both Myc and DNA synthesis. 相似文献
67.
Maniscalco M Dialetto G Tufano G Romano A Sofia M 《Respiration; international review of thoracic diseases》2003,70(2):207-210
Orthodeoxia-platypnea is a rare but increasingly recognized syndrome of upright hypoxemia usually associated to breathlessness relieved by recumbency. We report the case of isolated orthodeoxia discovered in a military recruit who referred only fatigability as the clinical symptom after a forced march. Transesophageal echocardiography demonstrated the presence of interatrial defect ostium secundum type with the persistence of left superior vena cava draining into coronary sinus. Right-to-left shunt was visualized by peripheral saline contrast infusion, despite normal right hemodynamics at heart catheterization. Hypoxemia recovered after the percutaneous closure of the interatrial defect. Orthodeoxia and platypnea could occur as separate disease manifestations, the latter probably being a rarer acute event, whereas orthodeoxia was underestimated and potentially earlier screenable. 相似文献
68.
69.
High Prevalence of Helicobacter pylori in Liver Cirrhosis (Relationship with Clinical and Endoscopic Features and the Risk of Peptic Ulcer) 总被引:14,自引:0,他引:14
Mario Miglioli Roberto Corinaldesi Luigi Bolondi Sebastiano Siringo Dino Vaira Marcello Menegatti Fabio Piscaglia Soccorsa Sofia Mariana Gaetani 《Digestive diseases and sciences》1997,42(10):2024-2030
In 153 consecutive patients with cirrhosis weassessed: (1) the prevalence of IgG to Helicobacterpylori and compared it with that found in 1010 blooddonors resident in the same area; and (2) therelationships of IgG to Helicobacter pylori with clinical andendoscopic features and with the risk of peptic ulcer.The IgG to Helicobacter pylori prevalence of cirrhoticswas significantly higher than in blood donors (76.5% vs 41.8%; P < 0.0005) and was notassociated with sex, cirrhosis etiology, Child class,gammaglobulins and hypertensive gastropathy. In bothgroups, the prevalence of IgG to Helicobacter pylori was significantly higher in subjects over 40. Amongpatients with cirrhosis a significantly higherprevalence of Helicobacter pylori was found in patientswith previous hospital admission (P = 0.02) and/or upper gastrointestinal endoscopy (P = 0.01) andpatients with peptic ulcer (P = 0.0004). Multivariateanalysis identified increasing age and male sex as riskfactors for a positive Helicobacter pylori serology and no independent risk factors for pepticulcer. The high prevalence of Helicobacterpylori-positive serology found in the present series isrelated to age and sex and might also be explained byprevious hospital admissions and/or uppergastrointestinal endoscopy. Our results do not confirmthe role of Helicobacter pylori as risk factor forpeptic ulcer in patients with liver cirrhosis. 相似文献
70.