全文获取类型
收费全文 | 1664篇 |
免费 | 158篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 86篇 |
妇产科学 | 30篇 |
基础医学 | 233篇 |
口腔科学 | 19篇 |
临床医学 | 235篇 |
内科学 | 293篇 |
皮肤病学 | 13篇 |
神经病学 | 162篇 |
特种医学 | 30篇 |
外科学 | 145篇 |
综合类 | 35篇 |
一般理论 | 1篇 |
预防医学 | 89篇 |
眼科学 | 25篇 |
药学 | 68篇 |
1篇 | |
中国医学 | 4篇 |
肿瘤学 | 351篇 |
出版年
2023年 | 16篇 |
2022年 | 31篇 |
2021年 | 51篇 |
2020年 | 44篇 |
2019年 | 46篇 |
2018年 | 51篇 |
2017年 | 36篇 |
2016年 | 42篇 |
2015年 | 48篇 |
2014年 | 47篇 |
2013年 | 75篇 |
2012年 | 105篇 |
2011年 | 95篇 |
2010年 | 71篇 |
2009年 | 61篇 |
2008年 | 113篇 |
2007年 | 129篇 |
2006年 | 110篇 |
2005年 | 105篇 |
2004年 | 95篇 |
2003年 | 78篇 |
2002年 | 82篇 |
2001年 | 22篇 |
2000年 | 24篇 |
1999年 | 26篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有1827条查询结果,搜索用时 812 毫秒
61.
62.
63.
Max J. Åström Mikaela B. von Bonsdorff Maija Haanpää Minna K. Salonen Hannu Kautiainen Johan G. Eriksson 《Primary Care Diabetes》2021,15(3):561-566
AimsTo assess if individuals with diabetes or prediabetes report more pain or have increased use of pain medication compared to normoglycaemic individuals.MethodsUsing cross-sectional data, we studied 928 men and 1075 women from the Helsinki Birth Cohort Study in 2001–2004 at a mean age of 61.5 years. Glucose regulation was assessed with a 2-h 75 g oral glucose tolerance test, and applying World Health Organization criteria, participants were defined as having normoglycaemia, prediabetes (impaired fasting glucose or impaired glucose tolerance), newly diagnosed diabetes or previously diagnosed diabetes. Self-reported pain intensity and interference during the previous 4 weeks was estimated using the RAND 36-Item Health Survey 1.0. Information on use of pain medication during the past 12 months was obtained from the Social Insurance Institution of Finland.ResultsThere was no difference in pain intensity or interference between glucose regulation groups for neither men nor women after adjusting for covariates (age, body mass index, education years, Beck Depression Inventory and physical activity). In addition, use of pain medication was similar between glucose regulation groups.ConclusionsAlthough pain is a common symptom in the general population, impairments in glucose regulation alone does not seem to increase pain among older individuals. 相似文献
64.
Ushanandini Mohanraj Maija Jokinen Rajita Rayamajhi Thapa Minna Paloniemi Timo Vesikari Maija Lappalainen Eveliina Tarkka Zaiga Nora-Krkle Anda Vilmane Kim Vettenranta Charles Mangani Sami Oikarinen Yue-Mei Fan Per Ashorn Elina Visnen Maria Sderlund-Venermo 《Viruses》2021,13(3)
Three human protoparvoviruses, bufavirus (BuV), tusavirus (TuV) and cutavirus (CuV), have recently been discovered in diarrheal stool. BuV has been associated with diarrhea and CuV with cutaneous T-cell lymphoma, but there are hardly any data for TuV or CuV in stool or respiratory samples. Hence, using qPCR and IgG enzyme immunoassays, we analyzed 1072 stool, 316 respiratory and 445 serum or plasma samples from 1098 patients with and without gastroenteritis (GE) or respiratory-tract infections (RTI) from Finland, Latvia and Malawi. The overall CuV-DNA prevalences in stool samples ranged between 0–6.1% among our six patient cohorts. In Finland, CuV DNA was significantly more prevalent in GE patients above rather than below 60 years of age (5.1% vs 0.2%). CuV DNA was more prevalent in stools among Latvian and Malawian children compared with Finnish children. In 10/11 CuV DNA-positive adults and 4/6 CuV DNA-positive children with GE, no known causal pathogens were detected. Interestingly, for the first time, CuV DNA was observed in two nasopharyngeal aspirates from children with RTI and the rare TuV in diarrheal stools of two adults. Our results provide new insights on the occurrence of human protoparvoviruses in GE and RTI in different countries. 相似文献
65.
Nonconventional opioid binding sites mediate growth inhibitory effects of methadone on human lung cancer cells. 总被引:2,自引:0,他引:2
R Maneckjee J D Minna 《Proceedings of the National Academy of Sciences of the United States of America》1992,89(4):1169-1173
Methadone was found to significantly inhibit the in vitro and in vivo growth of human lung cancer cells. The in vitro growth inhibition (occurring at 1-100 nM methadone) was associated with changes in cell morphology and viability detectable within 1 hr and was irreversible after a 24-hr exposure to the drug. These effects of methadone could be reversed in the first 6 hr by naltrexone, actinomycin D, and cycloheximide, suggesting involvement of opioid-like receptors and the requirement for de novo mRNA and protein synthesis. The inhibitory effects of methadone on the growth of lung cancer cells also could be achieved by the less addictive (+) isomer of methadone. Characterization of the methadone binding to lung cancer cell membranes revealed high-affinity (nM), saturable binding sites for (+/-)-[3H]methadone, which cross-reacted with ligands for kappa, phencyclidine, sigma, but not mu, and delta opioid receptors, and the binding characteristics appeared to be different from methadone sites present in rat brain. Methadone decreases cAMP levels in lung cancer cells, but the receptors are not coupled to a pertussis toxin-sensitive guanine nucleotide-binding regulatory protein. We conclude that the lung cancer growth inhibitory effects of methadone are significant, occur at low concentrations, and are mediated by a nonconventional type of opioid binding site distinct from methadone receptors found in the brain. 相似文献
66.
Adenylate cyclase and acetylcholine release regulated by separate serotonin receptors of somatic cell hybrids.
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J MacDermot H Higashida S P Wilson H Matsuzawa J Minna M Nirenberg 《Proceedings of the National Academy of Sciences of the United States of America》1979,76(3):1135-1139
Serotonin activates adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] of NCB-20 neuroblastoma--brain hybrid cells with an activation constant of 530 nM, but has little or no effect on cellular cyclic AMP or cyclic GMP content of NIE-115 neuroblastoma or NG108-15 hybrid cells. In homogenates of NCB-20 hybrid cells, lysergic acid diethylamide stimulates adenylate cyclase activity (Kact = 12 nM) and partially inhibits (Ki = 10 nM) the stimulation of adenylate cyclase activity by serotonin. No desensitization was detected of serotonin receptors coupled to adenylate cyclase. Serotonin also depolarizes NCB-20, NG108-15, and NIE-115 cells and increases acetylcholine release. Serotonin receptors mediating depolarizing responses desensitize rapidly and reversibly, and the depolarizing effects of serotonin are neither mimicked nor inhibited by lysergic acid diethylamide. These results indicate that (i) NCB-20 cells possess at least two species of serotonin receptors, which independently regulate cellular functions, (ii) activation of adenylate cyclase does not directly affect membrane potential or acetylcholine release, and (iii) serotonin-dependent cell depolarization does not affect cyclic AMP or cyclic GMP synthesis in the cell lines tested. 相似文献
67.
68.
Anja Hottinen Minna Rytil‐Manninen Jenny Laurn Silva Autio Tero Laiho Nina Lindberg 《International journal of mental health nursing》2020,29(3):399-405
The Safewards model was created to reduce conflict and containment in psychiatric inpatient units. The model suggests alternative methods for containment and aims to create a safer hospital experience for both patients and staff. The evaluation of this model has provided evidence that it might be implemented on adolescent psychiatric wards. This study evaluated the impact of the implementation process of the Safewards model on the social climate of adolescent psychiatric inpatient wards by using the Essen Climate Evaluation Schema questionnaire. The study was carried out on six closed wards of one Finnish hospital district. Data were collected at baseline (42 adolescent inpatients and 134 staff members) and after the implementation of the model (39 inpatients and 115 staff members). The data were analysed using the Mann–Whitney U‐test. The findings of this preliminary study indicate that inpatients' experience of patient cohesion and therapeutic hold and staff members' experience of safety on adolescent psychiatric wards might be improved by the implementation of the Safewards model on adolescent psychiatric wards. 相似文献
69.
70.