全文获取类型
收费全文 | 91754篇 |
免费 | 6685篇 |
国内免费 | 225篇 |
专业分类
耳鼻咽喉 | 1275篇 |
儿科学 | 2562篇 |
妇产科学 | 2257篇 |
基础医学 | 15053篇 |
口腔科学 | 2094篇 |
临床医学 | 8491篇 |
内科学 | 18019篇 |
皮肤病学 | 1445篇 |
神经病学 | 8848篇 |
特种医学 | 3918篇 |
外国民族医学 | 45篇 |
外科学 | 12141篇 |
综合类 | 1188篇 |
现状与发展 | 1篇 |
一般理论 | 111篇 |
预防医学 | 6850篇 |
眼科学 | 1991篇 |
药学 | 6485篇 |
中国医学 | 218篇 |
肿瘤学 | 5672篇 |
出版年
2022年 | 624篇 |
2021年 | 1506篇 |
2020年 | 944篇 |
2019年 | 1352篇 |
2018年 | 1664篇 |
2017年 | 1159篇 |
2016年 | 1393篇 |
2015年 | 1639篇 |
2014年 | 2053篇 |
2013年 | 3459篇 |
2012年 | 4501篇 |
2011年 | 4536篇 |
2010年 | 3161篇 |
2009年 | 2711篇 |
2008年 | 4159篇 |
2007年 | 4323篇 |
2006年 | 4244篇 |
2005年 | 4180篇 |
2004年 | 4219篇 |
2003年 | 3864篇 |
2002年 | 3891篇 |
2001年 | 2743篇 |
2000年 | 2857篇 |
1999年 | 2500篇 |
1998年 | 1210篇 |
1997年 | 969篇 |
1996年 | 897篇 |
1995年 | 924篇 |
1994年 | 749篇 |
1993年 | 804篇 |
1992年 | 1801篇 |
1991年 | 1725篇 |
1990年 | 1665篇 |
1989年 | 1625篇 |
1988年 | 1373篇 |
1987年 | 1366篇 |
1986年 | 1316篇 |
1985年 | 1246篇 |
1984年 | 931篇 |
1983年 | 837篇 |
1982年 | 663篇 |
1981年 | 641篇 |
1980年 | 547篇 |
1979年 | 793篇 |
1978年 | 524篇 |
1977年 | 501篇 |
1976年 | 470篇 |
1975年 | 518篇 |
1974年 | 602篇 |
1973年 | 515篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
Dana Franzen-Klein Mark Jankowski Charlotte L. Roy Hoa Nguyen-Phuc Da Chen Lorin Neuman-Lee 《Journal of toxicology and environmental health. Part A》2020,83(2):45-65
ABSTRACTDomestic chickens (Gallus gallus domesticus) were exposed to imidacloprid by gavage once daily for 7 consecutive days at 0, 0.03, 0.34, 3.42, 10.25, and 15.5 mg/kg/day (n = 20 per group; 5 6-week-old males, 5 6-week-old females, 5 9-week-old males, and 5 9-week-old females). The severity and duration of neurobehavioral abnormalities were recorded. Components of the innate and adaptive immune system were assessed with 7 standard functional assays. Temporary neurobehavioral abnormalities were observed in a dose-dependent manner, including muscle tremors, ataxia, and depressed mentation. Based upon mean clinical severity scores, the no observed adverse effect level (NOAEL) was 3.42 mg/kg/day, and the lowest observed adverse effect level (LOAEL) was 10.25 mg/kg/day. The effective dose value for the presence of any neurobehavioral abnormalities in 50% of the test group (ED50) was 4.62 ± 0.98 mg/kg/day. The ED50 for an adjusted score that included both severity and duration of neurobehavioral abnormalities was 11.24 ± 9.33 mg/kg/day. These ED50 values are equivalent to a 1 kg bird ingesting 29 or 70 imidacloprid treated soybean seeds respectively. Immunotoxicity was not documented, possible causes include the assays were insensitive, relevant immune functions were not examined, or imidacloprid is not immunotoxic at this dosing schedule in this species. Neurobehavioral abnormalities were a more sensitive indicator of the sublethal effects of imidacloprid than immunotoxicity. 相似文献
6.
Factors predicting the development of pressure ulcers in an at‐risk population who receive standardized preventive care: secondary analyses of a multicentre randomised controlled trial 下载免费PDF全文
7.
8.
Bielik Peter Bonczek Ondřej Krejčí Přemysl Zeman Tomáš Izakovičová-Hollá Lydie Šoukalová Jana Vaněk Jiří Vojtěšek Bořivoj Lochman Jan Balcar Vladimir J. Šerý Omar 《Clinical oral investigations》2022,26(12):7045-7055
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of... 相似文献
9.
W. Do T. Elzerman R. de Bree A. Rosenberg T. Forouzanfar E.M. Van Cann 《International journal of oral and maxillofacial surgery》2021,50(5):591-597
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. 相似文献
10.
Fabrice Barlesi Edward B. Garon Dong-Wan Kim Enriqueta Felip Ji-Youn Han Joo-Hang Kim Myung-Ju Ahn Mary Jo Fidler Matthew A. Gubens Gilberto de Castro Veerle Surmont Qiao Li Anne C. Deitz Gregory M. Lubiniecki Roy S. Herbst 《Journal of thoracic oncology》2019,14(5):793-801