全文获取类型
收费全文 | 4304篇 |
免费 | 240篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 67篇 |
妇产科学 | 82篇 |
基础医学 | 502篇 |
口腔科学 | 64篇 |
临床医学 | 335篇 |
内科学 | 1453篇 |
皮肤病学 | 69篇 |
神经病学 | 507篇 |
特种医学 | 211篇 |
外科学 | 574篇 |
综合类 | 20篇 |
预防医学 | 116篇 |
眼科学 | 44篇 |
药学 | 202篇 |
中国医学 | 16篇 |
肿瘤学 | 322篇 |
出版年
2023年 | 33篇 |
2022年 | 72篇 |
2021年 | 119篇 |
2020年 | 87篇 |
2019年 | 95篇 |
2018年 | 134篇 |
2017年 | 113篇 |
2016年 | 128篇 |
2015年 | 133篇 |
2014年 | 186篇 |
2013年 | 261篇 |
2012年 | 359篇 |
2011年 | 343篇 |
2010年 | 213篇 |
2009年 | 196篇 |
2008年 | 294篇 |
2007年 | 286篇 |
2006年 | 261篇 |
2005年 | 300篇 |
2004年 | 261篇 |
2003年 | 196篇 |
2002年 | 158篇 |
2001年 | 25篇 |
2000年 | 19篇 |
1999年 | 25篇 |
1998年 | 22篇 |
1997年 | 29篇 |
1996年 | 28篇 |
1995年 | 27篇 |
1994年 | 14篇 |
1993年 | 10篇 |
1992年 | 19篇 |
1991年 | 19篇 |
1990年 | 18篇 |
1989年 | 12篇 |
1988年 | 17篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 12篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1970年 | 4篇 |
1968年 | 2篇 |
排序方式: 共有4598条查询结果,搜索用时 15 毫秒
51.
Maria Ricciardi Daniele Cespi Maurizio Celentano Alessandra Genga Cosimino Malitesta Antonio Proto Carmine Capacchione Raffaele Cucciniello 《Sustainable Chemistry and Pharmacy》2017
The production of chemicals from bio-based feedstocks is an emerging field of research in both industrial and academic communities. Here we present the synthesis of propylene glycol through catalytic hydrogenolysis of glycidol, obtained using a side-stream from the bio-based epichlorohydrin production plant, over Pd/C catalyst. In particular, we show the prominent effect of the acidic resin Amberlyst-15 in the selective and quantitative conversion of glycidol that permits to reach a TOF value of 162 h?1. Propylene glycol is obtained with high yields and selectivity (> 99%) in only 1 h under mild reaction conditions. The effect of solvent is also investigated giving interesting results on the reaction selectivity. The catalytic system (Pd/C + Amberlyst-15) shows a good recyclability also after seven reaction cycles reaching high performances in term of conversion and selectivity. This allowed minimizing the amount of waste and enhancing the efficiency of the whole system. 相似文献
52.
53.
54.
55.
Mariangela Lopopolo Giannapia Affaitati Alessandra Fabrizio Francesca Massimini Domenico Lapenna Maria Adele Giamberardino Raffaele Costantini 《Fundamental & clinical pharmacology》2014,28(3):331-341
The effects of tramadol versus placebo administration on behavioral indicators of ureteral pain, pelvic pain and referred lumbar muscle hyperalgesia were investigated in a rat model of viscero‐visceral hyperalgesia from endometriosis plus ureteral calculosis (endo + stone). Fifty female Sprague‐Dawley rats underwent surgical induction of endometriosis and, 2 weeks later, were randomly assigned to five groups (10 each), to be treated i.p., twice a day, with tramadol (0.625, 1.25, 2.5, or 5 mg/kg) or saline for 5 days (14–18th day postendometriosis; prestone treatment). On the 21st day, they underwent laparotomy for stone formation in the upper left ureter (dental cement injection). All were video‐taped 24 h nonstop for 7 days before and 4 days after stone formation (14–25th day postendometriosis) to record ureteral and pelvic pain behaviors. Lumbar sensitivity (L1) was tested bilaterally, daily over the same period, by verifying presence/absence of vocalization upon muscle pinching at a predefined pressure (calibrated forceps). Additional fifty endo + stone rats underwent the same protocol, except that treatment was performed on 21st–25th day (poststone treatment). Tramadol vs. saline significantly reduced number and duration of ureteral crises, duration of pelvic behavior, and incidence of muscle hyperalgesia (P < 0.0001), with a dose‐dependent effect. Prestone treatment was significantly more effective than poststone treatment for the 1.25 dose for all parameters and 2.5 dose for pelvic and muscle parameters (0.003 > P < 0.02). Tramadol, even at low doses, is thus highly protective against pain from ‘viscero‐visceral hyperalgesia’ in endometriosis plus ureteral calculosis; it can represent a valid therapeutic approach in women with these comorbidities. 相似文献
56.
Luca Arcaini Michele Merli Francesco Passamonti Raffaele Bruno Ercole Brusamolino Paolo Sacchi Sara Rattotti Ester Orlandi Elisa Rumi Virginia Ferretti Silvia Rizzi Erika Meli Cristiana Pascutto Marco Paulli Mario Lazzarino 《American journal of hematology》2010,85(1):46-50
We studied 160 Hepatitis C virus (HCV)‐positive patients with NHL (59 indolent NHL, 101 aggressive). Median age was 67 years. HCV‐RNA was present in 146. HBsAg was positive in seven patients. At diagnosis, ALT value was above UNL in 67 patients. One hundred and twenty patients received an anthracycline‐based therapy, alkylators, 28 received chemotherapy plus rituximab. Cytotoxic drugs dose was reduced in 63 patients. Among 93 patients with normal ALT at presentation, 16 patients developed WHO grade II–III liver toxicity. Among 67 patients with abnormal ALT, eight patients had a 3.5 times elevation during treatment. Among 28 patients treated with rituximab and chemotherapy, five patients (18%) developed liver toxicity. Thirty four patients (21%) did not complete treatment (eight for liver toxicity). Median progression‐free survival (PFS) for patients who experienced liver toxicity is significantly shorter than median PFS of patients without toxicity (respectively, 2 years and 3.7 years, P = 0.03). After a median F‐UP of 2 years, 32 patients died (three for hepatic failure). A significant proportion of patients with HCV+ NHL develop liver toxicity often leading to interruption of treatment. This could be a limit to the application of immunochemotherapy programs. HCV+ lymphomas represent a distinct clinical subset of NHL that deserves specific clinical approach to limit liver toxicity and ameliorate survival. Am. J. Hematol., 2010. © 2009 Wiley‐Liss, Inc. 相似文献
57.
Montalto M Izzi D La Regina M Nucera G Manna R Gasbarrini G 《The American journal of the medical sciences》2004,327(5):275-277
Streptococcus bovis is one of the nonenterococcal species included among the streptococci group D. It is part of the normal bowel flora in humans and animals, but it is also responsible for infectious diseases (10-15% of all cases of bacterial endocarditis). Many cases of bacteremia and metastatic abscesses (spleen, liver, soft tissues, bone, meninges, endocardium) caused by S. bovis were reported as associated with digestive tract diseases, mainly colonic disease, and, in particular colonic neoplasms, or chronic liver diseases. A role in carcinogenesis has been suggested for this microorganism. The authors report two cases of S. bovis sepsis, one associated with colonic neoplasm and the other with liver cirrhosis and gastric carcinoma. Discussion is focused on probable mechanisms that favor gastric colonization and systemic diffusion of S. bovis from the gut in patients with gastrointestinal neoplasms or chronic liver disease and provides clinical recommendations for patients with S. bovis infections. 相似文献
58.
59.
60.