全文获取类型
收费全文 | 2877篇 |
免费 | 224篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 160篇 |
妇产科学 | 22篇 |
基础医学 | 536篇 |
口腔科学 | 56篇 |
临床医学 | 271篇 |
内科学 | 587篇 |
皮肤病学 | 18篇 |
神经病学 | 313篇 |
特种医学 | 107篇 |
外科学 | 358篇 |
综合类 | 10篇 |
预防医学 | 199篇 |
眼科学 | 5篇 |
药学 | 186篇 |
中国医学 | 5篇 |
肿瘤学 | 253篇 |
出版年
2024年 | 4篇 |
2023年 | 21篇 |
2022年 | 58篇 |
2021年 | 95篇 |
2020年 | 70篇 |
2019年 | 80篇 |
2018年 | 80篇 |
2017年 | 78篇 |
2016年 | 69篇 |
2015年 | 101篇 |
2014年 | 102篇 |
2013年 | 162篇 |
2012年 | 219篇 |
2011年 | 218篇 |
2010年 | 110篇 |
2009年 | 123篇 |
2008年 | 192篇 |
2007年 | 208篇 |
2006年 | 179篇 |
2005年 | 178篇 |
2004年 | 165篇 |
2003年 | 134篇 |
2002年 | 152篇 |
2001年 | 25篇 |
2000年 | 17篇 |
1999年 | 23篇 |
1998年 | 36篇 |
1997年 | 24篇 |
1996年 | 26篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 3篇 |
1989年 | 10篇 |
1988年 | 3篇 |
1987年 | 8篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 8篇 |
1971年 | 2篇 |
排序方式: 共有3111条查询结果,搜索用时 15 毫秒
51.
Adil A. Shah Umar F. Bhatti Mikael Petrosyan George Washington Wasay Nizam Mallory Williams Daniel Tran Edward E. Cornwell Terrence M. Fullum 《American journal of surgery》2019,217(4):732-738
Background
Laparoscopic cholecystectomy (LC) is the standard operative intervention for gallbladder disease. Complications may necessitate conversion to an open cholecystectomy (OC). This study aims to determine the cost-consequences of laparoscopic-to-open conversion using a nationally-representative sample.Methods
Using the National Inpatient Sample (2007–2011), adult patients undergoing emergent LC were identified. Patients undergoing secondary-conversion to OC were subsequently identified. Multivariable regression analyses, accounting for differences in propensity-quintile, mortality, length of stay, and hospital-level factors were then performed to assess for differences in the odds of conversion and total predicted mean costs per index-hospitalization.Results
Of 225,805 observations, conversion to open occurred in 1.86% (n?=?4203) of cases. Increased age, African-American ethnicity, public-insurance and teaching-hospital status were associated with a higher likelihood of conversion (p?<?0.05) after risk-adjustment. Risk-adjusted odds of conversion increased by 34% (95%CI:1.33–1.36) for each day surgery was delayed. Risk-adjusted costs, were 259% higher (absolute-difference $23,358,p?<?0.05) with conversion. Mortality was higher amongst patients undergoing conversion to open (4.98% vs 0.34%,p?<?0.001).Conclusion
Patients undergoing conversion from laparoscopic to open cholecystectomy are at an increased risk of receiving disparate care and increased mortality. 相似文献52.
53.
Pia Bükmann Larsen Elin Storjord Åsne Bakke Tone Bukve Mikael Christensen Joakim Eikeland 《Scandinavian journal of clinical and laboratory investigation》2017,77(2):115-121
Regular measurement of prothrombin time as an international normalized ratio PT (INR) is mandatory for optimal and safe use of warfarin. Scandinavian evaluation of laboratory equipment for primary health care (SKUP) evaluated the microINR portable coagulometer (microINR®) (iLine Microsystems S.L., Spain) for measurement of PT (INR). Analytical quality and user-friendliness were evaluated under optimal conditions at an accredited hospital laboratory and at two primary health care centres (PHCCs). Patients were recruited at the outpatient clinic of the Laboratory of Medical Biochemistry, St Olav’s University Hospital, Trondheim, Norway (n?=?98) and from two PHCCs (n?=?88). Venous blood samples were analyzed under optimal conditions on the STA-R®Evolution with STA-SPA?+?reagent (Stago, France) (Owren method), and the results were compared to capillary measurements on the microINR®. The imprecision of the microINR® was 6% (90% CI: 5.3–7.0%) and 6.3% (90% CI: 5.1–8.3) in the outpatient clinic and PHCC2, respectively for INR ≥2.5. The microINR® did not meet the SKUP quality requirement for imprecision ≤5.0%. For INR <2.5 at PHCC2 and at both levels in PHCC1, CV% was ≤5.0. The accuracy fulfilled the SKUP quality goal in both outpatient clinic and PHCCs. User-friendliness of the operation manual was rated as intermediate, defined by SKUP as neutral ratings assessed as neither good nor bad. Operation facilities was rated unsatisfactory, and time factors satisfactory. In conclusion, quality requirements for imprecision were not met. The SKUP criteria for accuracy was fulfilled both at the hospital and at the PHCCs. The user-friendliness was rated intermediate. 相似文献
54.
Kun Sun Jeanette Br?ms Moa Lavander Bharat Kumar Gurram Per-Anders Enquist C. David Andersson Mikael Elofsson Anders Sj?stedt 《Antimicrobial agents and chemotherapy》2014,58(7):4123-4130
The type VI secretion system (T6SS) is the most prevalent bacterial secretion system and an important virulence mechanism utilized by Gram-negative bacteria, either to target eukaryotic cells or to combat other microbes. The components show much variability, but some appear essential for the function, and two homologues, denoted VipA and VipB in Vibrio cholerae, have been identified in all T6SSs described so far. Secretion is dependent on binding of an α-helical region of VipA to VipB, and in the absence of this binding, both components are degraded within minutes and secretion is ceased. The aim of the study was to investigate if this interaction could be blocked, and we hypothesized that such inhibition would lead to abrogation of T6S. A library of 9,600 small-molecule compounds was screened for their ability to block the binding of VipA-VipB in a bacterial two-hybrid system (B2H). After excluding compounds that showed cytotoxicity toward eukaryotic cells, that inhibited growth of Vibrio, or that inhibited an unrelated B2H interaction, 34 compounds were further investigated for effects on the T6SS-dependent secretion of hemolysin-coregulated protein (Hcp) or of phospholipase A1 activity. Two compounds, KS100 and KS200, showed intermediate or strong effects in both assays. Analogues were obtained, and compounds with potent inhibitory effects in the assays and desirable physicochemical properties as predicted by in silico analysis were identified. Since the compounds specifically target a virulence mechanism without affecting bacterial replication, they have the potential to mitigate the virulence with minimal risk for development of resistance. 相似文献
55.
56.
57.
Erik Smedler Christoph Ab Erik Plsson Martin Ingvar Mikael Landn 《Journal of psychiatry & neuroscience : JPN》2020,45(3):182
BackgroundThe CACNA1C gene encodes the 1C subunit of L-type voltage-gated calcium channels and has been associated with several psychiatric syndromes — including bipolar disorder — in many genome-wide association studies. Experimental and clinical studies have reported changes with respect to behaviour and biomarkers in risk allele carriers, corroborating the essential role of the CACNA1C gene in neurons, during development and in the mature brain. However, the association of this gene with regional cortical thickness has not been evaluated in patients with bipolar disorder.MethodsUsing magnetic resonance imaging, we measured the average cortical thickness of 68 brain regions in 87 patients genotyped for the single-nucleotide polymorphism rs1006737 in CACNA1C.ResultsWe found associations with the mean thickness of several cortical areas: the left lateral orbitofrontal and rostral anterior cingulate cortices, as well as other parts of the frontal and parietal cortices.Limitations: This cross-sectional cohort study could not fully differentiate correlation from causation.ConclusionThe CACNA1C polymorphism rs1006737 is associated with the mean thickness of cortical brain areas that have been shown to be altered in bipolar disorder. 相似文献
58.
59.
Karla Klein Murdock Mikael Horissian Caroline Crichlow-Ball 《Behavioral sleep medicine》2017,15(3):228-241
Emerging adults use text messaging as a principal form of social communication, day and night, and this may compromise their sleep. In this study, a hypothetical model was tested linking daytime and nighttime text message use with multiple sleep characteristics. Subjective and objective measures of texting and sleep were utilized to assess 83 college students over a seven-day period during an academic term. Greater number of daily texts, awareness of nighttime cell phone notifications, and compulsion to check nighttime notifications were significantly associated with poorer subjective sleep quality. Awareness of nighttime notifications was significantly associated with higher self-reported global sleep problems and more sleep disruptions. Results suggest potential benefits of targeting nighttime texting habits in health promotion efforts for emerging adults. 相似文献
60.