全文获取类型
收费全文 | 1359篇 |
免费 | 131篇 |
专业分类
1490篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 14篇 |
2021年 | 33篇 |
2020年 | 25篇 |
2019年 | 26篇 |
2018年 | 26篇 |
2017年 | 35篇 |
2016年 | 33篇 |
2015年 | 58篇 |
2014年 | 80篇 |
2013年 | 105篇 |
2012年 | 129篇 |
2011年 | 112篇 |
2010年 | 78篇 |
2009年 | 57篇 |
2008年 | 83篇 |
2007年 | 83篇 |
2006年 | 98篇 |
2005年 | 75篇 |
2004年 | 68篇 |
2003年 | 62篇 |
2002年 | 65篇 |
2001年 | 4篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 20篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有1490条查询结果,搜索用时 15 毫秒
101.
Gideon Y. Stein Gabriel Herscovici Roman Korenfeld Shlomi Matetzky Shmuel Gottlieb Danny Alon Natalie Gevrielov-Yusim Zaza Iakobishvili Shmuel Fuchs 《PloS one》2014,9(1)
Background
Type-II MI is defined as myocardial infarction (MI) secondary to ischemia due to either increased oxygen demand or decreased supply. This categorization has been used for the last five years, yet, little is known about patient characteristics and clinical outcomes. In the current work we assessed the epidemiology, causes, management and outcomes of type II MI patients.Methods
A comparative analysis was performed between patients with type-I and type-II MI who participated in two prospective national Acute Coronary Syndrome Israeli Surveys (ACSIS) performed in 2008 and 2010.Results
The surveys included 2818 patients with acute MI of whom 127 (4.5%) had type-II MI. The main causes of type-II MI were anemia (31%), sepsis (24%), and arrhythmia (17%). Patients with type-II MI tended to be older (75.6±12 vs. 63.8±13, p<0.0001), female majority (43.3% vs. 22.3%, p<0.0001), had more frequently impaired functional level (45.7% vs. 17%, p<0.0001) and a higher GRACE risk score (150±32 vs. 110±35, p<0.0001). Patients with type-II MI were significantly less often referred for coronary interventions (36% vs. 89%, p<0.0001) and less frequently prescribed guideline-directed medical therapy. Mortality rates were substantially higher among patients with type-II MI both at thirty-day (13.6% vs. 4.9%, p<0.0001) and at one-year (23.9% vs. 8.6%, p<0.0001) follow-ups.Conclusions
Patients with type-II compared to type-I MI have distinct demographics, increased prevalence of multiple comorbidities, a high-risk cardiovascular profile and an overall worse outcome. The complex medical condition of this cohort imposes a great therapeutic challenge and specific guidelines with recommended medical treatment and invasive strategies are warranted. 相似文献102.
Nitric oxide (NO) is a critical biological mediator involved in numerous diseases. However, the short lifetime of this molecule in biological conditions can make its study in situ complicated. Here, we review some recent results on the role of NO in angiogenesis, obtained using a biocompatible microelectrode array. This simple system allowed for the quick and easy quantification of NO released from cells grown directly on the surface of the sensor. We have used this technology to demonstrate that angiogenin induces NO release, and to partially elucidate its intracellular transduction pathway. 相似文献
103.
104.
Randomized controlled trial of a nationally available weight control program tailored for adults with type 2 diabetes 下载免费PDF全文
Patrick M. O'Neil Peter W. Tuerk Lynne E. Becker Thomas A. Wadden Ken Fujioka Priscilla L. Hollander Robert F. Kushner W. Timothy Garvey Domenica M. Rubino Robert J. Malcolm Daniel Weiss William J. Raum Jonny L. Salyer Kathie L. Hermayer Jan L. Veliko Nicoleta D. Sora 《Obesity (Silver Spring, Md.)》2016,24(11):2269-2277
105.
106.
107.
Pugia MJ Jortani SA Basu M Sommer R Kuo HH Murphy S Williamson D Vranish J Boyle PJ Budzinski D Valdes R Basu SC 《Glycoconjugate journal》2007,24(1):5-15
Urinary trypsin inhibitors (uTi) suppress serine proteases during inflammation. After liberation from proinhibitors (P-alpha-I
and I-alpha-I) by the white blood cell (WBC) response, uTi readily pass through the kidneys into urine. A key uTi, bikunin,
is attached to O-linked and N-linked glycoconjugates. Recently, uTi inhibitors, called uristatins, were found to lack the
O-linked glycoconjugates. Monoclonal antibodies were produced using purified uristatin and screened for binding differences
to uristatin, bikunin, P-α-I, and I-α-I. Antibody-binding patterns were characterized using immunoaffinity binding onto protein-chip
surfaces and analysis by Surface Enhanced Laser Desorption/Ionization mass spectrometry (SELDI), using specimens from patients
and from purified uTi standards. Antibodies were developed and used in an enzyme-linked immunosorbent assay (ELISA) method
for uTi measurement in urine and plasma specimens. ELISA was performed on specimens from normal, presumed healthy, controls
and from patients who had been screened for inflammation using a high sensitivity C-reactive protein (CRP) test and a complete
blood count (CBC). Polyclonal antibody against uTi showed cross-reactivity with the Tamm–Horsfall protein (THP) and with proinhibitors.
Screening of anti-uTi monoclonal antibodies (Mab) revealed antibodies that did not cross-react with either of the above, thus
providing a tool to measure both uristatin and bikunin in urine with Mab 3G5 and in plasma with Mab 5D11. The monoclonal antibody
5D11 cross-reacts with specific N-linked glycoconjugates of uristatin present in plasma. In ca 96% of healthy adults, uTi
were present at <12 mg/l in urine and <4 mg/l in plasma. We also found that patients with an inflammation and a CRP of >2.0 mg/l
had higher urinary concentrations of uTi than the control population in every subject. Free uristatin and bikunin pass readily
into urine and are primarily bound to heavy chains that constitute the proinhibitor form in plasma. 相似文献
108.
We investigated the long-term effects of divorce and early separation from one parent on HPA axis reactivity, in young adults without psychopathology. Participants were 44 young subjects, 22 whose parents divorced before they reached age 10, and 22 controls. Psychiatric symptomatology was measured with the Brief Symptom Inventory (BSI), family perceived stress by the Dyadic Adjustment Scale (DAS), and bonding by the Parental Bonding Instrument (PBI). Assessment of HPA axis function included baseline morning cortisol and ACTH and cortisol response to a CRH stimulation test. No baseline or stimulated group differences were observed for ACTH. Cortisol levels were consistently but insignificantly lower in the divorce group throughout the CRH stimulation reaching statistical significance only at 5 min (p<0.03). Group by time effect reached a trend level (p<0.06). A correlation was found between psychiatric symptomatology and PBI scores; however, both parameters did not correlate with HPA axis activity. A significant correlation was found between DAS scores and ACTH. A regression model revealed a contributing effect for both family stress and child-parent bonding to stimulated ACTH levels. These preliminary findings suggest that even in the absence of adult psychopathology, a history of childhood separation from one parent due to divorce may lead to detectable, albeit mild, long-term alterations in HPA axis activity. Furthermore, they suggest that level of stress at home and parental bonding are important determinants of this effect. It is likely that divorce has significant and sustained effects on children's HPA axis only in the context of a traumatic separation. 相似文献
109.
Objectives To explore whether the apparent impact of income inequality on health, which has been shown for wealthier nations, is replicated worldwide, and whether the impact varies by age.Design Observational study. Setting 126 countries of the world for which complete data on income inequality and mortality by age and sex were available around the year 2002 (including 94.4% of world human population).Data sources Data on mortality were from the World Health Organization and income data were taken from the annual reports of the United Nations Development Programme.Main outcome measures Mortality in 5-year age bands for each sex by income inequality and income level.Results At ages 15-29 and 25-39 variations in income inequality seem more closely correlated with mortality worldwide than do variations in material wealth. This relation is especially strong among the poorest countries in Africa. Mortality is higher for a given level of overall income in more unequal nations.Conclusions Income inequality seems to have an influence worldwide, especially for younger adults. Social inequality seems to have a universal negative impact on health. 相似文献
110.
The Latin word "facultas" literally means "opportunity." Facultative heterochromatin (fHC) then designates genomic regions in the nucleus of a eukaryotic cell that have the opportunity to adopt open or compact conformations within temporal and spatial contexts. This review focuses on the molecular and functional aspects of fHC that distinguish it from constitutive heterochromatin (cHC) and euchromatin (EC) and discusses various concepts regarding the regulation of fHC structure. We begin by revisiting the historical developments that gave rise to our current appreciation of fHC. 相似文献