全文获取类型
收费全文 | 1201篇 |
免费 | 90篇 |
专业分类
1291篇 |
出版年
2021年 | 17篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 12篇 |
2015年 | 26篇 |
2014年 | 37篇 |
2013年 | 45篇 |
2012年 | 52篇 |
2011年 | 48篇 |
2010年 | 33篇 |
2009年 | 36篇 |
2008年 | 46篇 |
2007年 | 46篇 |
2006年 | 36篇 |
2005年 | 55篇 |
2004年 | 42篇 |
2003年 | 44篇 |
2002年 | 33篇 |
2001年 | 31篇 |
2000年 | 30篇 |
1999年 | 29篇 |
1998年 | 20篇 |
1997年 | 20篇 |
1996年 | 14篇 |
1995年 | 10篇 |
1994年 | 16篇 |
1993年 | 16篇 |
1992年 | 29篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 11篇 |
1988年 | 19篇 |
1987年 | 21篇 |
1986年 | 14篇 |
1985年 | 16篇 |
1984年 | 19篇 |
1983年 | 10篇 |
1981年 | 14篇 |
1979年 | 9篇 |
1978年 | 17篇 |
1977年 | 10篇 |
1975年 | 11篇 |
1974年 | 8篇 |
1973年 | 16篇 |
1972年 | 15篇 |
1971年 | 13篇 |
1970年 | 11篇 |
1932年 | 9篇 |
排序方式: 共有1291条查询结果,搜索用时 0 毫秒
111.
112.
113.
Hozawa A Okamura T Oki I Murakami Y Kadowaki T Nakamura K Miyamatsu N Hayakawa T Kita Y Nakamura Y Nakamura Y Abbott RD Okayama A Ueshima H;NIPPON DATA Study Group 《Obesity (Silver Spring, Md.)》2008,16(7):1714-1717
As body composition in Asian populations is largely different from Western populations, a healthy BMI could also differ between the two populations. Thus, further study is needed to determine whether a healthy BMI in Asians should be lower than Western populations, as recommended by the World Health Organization (WHO). We investigated the relationship between BMI and mortality in a sample of 8,924 Japanese men and women without stroke or heart disease. During 19 years of follow-up, 1,718 deaths were observed. We found a U-shaped relationship between BMI and fatal events. Risk of total mortality was highest in participants with BMI <18.5 kg/m(2) and lowest in participants with BMI 23.0-24.9 kg/m(2). These findings persisted even after excluding the first 5 years of follow-up with a focus on healthy participants who never smoked, were aged <70 years, and had total cholesterol (TC) levels >or=4.1 mmol/l (N=3712). For both the full sample and healthy participants, all-cause mortality risk did not differ between BMI ranges 21.0-22.9 and 23.0-24.9 kg/m(2). Our findings do not support the recent WHO implications that BMIs <23.0 kg/m(2) is healthy for Asians. Therefore, further studies are needed to identify an optimal BMI range for Asia. 相似文献
114.
Variation in heat-shock proteins among species of desert fishes (Poeciliidae, Poeciliopsis) 总被引:4,自引:0,他引:4
Analysis of the heat-shock proteins (hsps) of six closely related species
of Poeciliopsis demonstrated the existence of biochemical diversity in the
hsp100, hsp70, hsp60, and hsp30 protein families among species. Each
species expressed five to seven hsp70-related isoforms. Constitutive 70-kD
isoforms were identical among species, but four different patterns of
heat-inducible isoforms were seen in these six species. Members of the
hsp70 family of molecular chaperones are included among the most highly
conserved proteins known, and the possibility of variation in hsp70 among
closely related species has rarely been addressed. The hsp30 family is
known to be less conserved than the hsp70 family, and, as expected, the
Poeciliopsis hsp30 patterns showed more variation. Most of the hsp30
isoforms characteristic of a particular species were unique to that
species. Hsp100 and hsp60 were identical in five of the species, but
alternate isoforms were found in P. monacha. The small size and limited
geographical distribution of the P. monacha population have probably
contributed to the uniqueness of the monacha pattern. Two of the species
were shown to acquire thermotolerance, the ability to withstand normally
lethal temperatures when subjected to a gradual temperature increase.
Rapid-heating protocols commonly used to establish critical thermal maxima
of organisms do not include this inducible component of thermoresistance
and therefore do not adequately assess an organism's capacity to withstand
thermal stress.
相似文献
115.
Robert W. Keane Ursula K. Abbott J.Lynne Brown Vernon M. Ingram 《Developmental biology》1974,38(2):229-236
A new autosomal codominant hemoglobin mutation alters hemoglobin M of the primitive red cell line and hemoglobin D found in definitive cells. That Hb M and Hb D are altered by the same gene mutation supports the idea that Hb M shares a polypeptide chain with Hb D. It is concluded that in the switch from primitive hemoglobins to those of the definitive type, there are at least two α chains conserved; αA of Hb E in Hb A and αD of Hb M in Hb D. 相似文献
116.
Coordinated regulation of Toll-like receptor and NOD2 signaling by K63-linked polyubiquitin chains 总被引:2,自引:1,他引:2 下载免费PDF全文
Abbott DW Yang Y Hutti JE Madhavarapu S Kelliher MA Cantley LC 《Molecular and cellular biology》2007,27(17):6012-6025
K63 polyubiquitin chains spatially and temporally link innate immune signaling effectors such that cytokine release can be coordinated. Crohn's disease is a prototypical inflammatory disorder in which this process may be faulty as the major Crohn's disease-associated protein, NOD2 (nucleotide oligomerization domain 2), regulates the formation of K63-linked polyubiquitin chains on the I kappa kinase (IKK) scaffolding protein, NEMO (NF-kappaB essential modifier). In this work, we study these K63-linked ubiquitin networks to begin to understand the biochemical basis for the signaling cross talk between extracellular pathogen Toll-like receptors (TLRs) and intracellular pathogen NOD receptors. This work shows that TLR signaling requires the same ubiquitination event on NEMO to properly signal through NF-kappaB. This ubiquitination is partially accomplished through the E3 ubiquitin ligase TRAF6. TRAF6 is activated by NOD2, and this activation is lost with a major Crohn's disease-associated NOD2 allele, L1007insC. We further show that TRAF6 and NOD2/RIP2 share the same biochemical machinery (transforming growth factor beta-activated kinase 1 [TAK1]/TAB/Ubc13) to activate NF-kappaB, allowing TLR signaling and NOD2 signaling to synergistically augment cytokine release. These findings suggest a biochemical mechanism for the faulty cytokine balance seen in Crohn's disease. 相似文献
117.
James G. Abbott Lisa M. Campbell Clinton J. Hay Tor F. Næsje John Purvis 《Human ecology: an interdisciplinary journal》2007,35(5):559-574
This paper examines small-scale fish vending in a southern African floodplain from two perspectives: as a link between natural
resource use and consumption, and as a livelihood in itself. We used a combination of observation, surveys and semistructured
interviews in a market in Katima Mulilo, Namibia, to determine sources of fish, preferences and constraints to vending, average
investment and profit, as well different routes into fish vending and perceptions regarding vending. Most vendors come from
fishing households, but their stock is often an accumulation of purchases from other fishers. There is little evidence of
formal arrangements between fishers and vendors, yet most adapt to the highly variable natural and social environments of
the region. Although all vendors ranked selling fish as their most important livelihood activity, a wide range of investment
and profit exists among individuals. Our findings indicate that fisheries management proposed for the area must be developed
with a careful understanding of how changes in access and use will affect vending livelihoods.
相似文献
John PurvisEmail: |
118.
J Watkins E C Abbott C N Hensby J Webster C T Dollery 《BMJ (Clinical research ed.)》1980,281(6242):702-705
The effects of 100 mg indomethacin daily for three weeks on blood pressure and urinary excretion of prostaglandin F2 alpha were studied in a double-blind, placebo-controlled comparison of two groups of patients with essential hypertension, eight receiving propranolol and seven thiazide diuretics. Compared with placebo, adding indomethacin to the patients'' established antihypertensive treatment increased blood pressure by 14/5 Hg supine and 16/9 mm Hg erect in the patients receiving propranolol, and by 13/9 mm Hg supine and 16/9 mm Hg erect in the patients receiving thiazide diuretics (all p less than or equal to 0.05). The excretion of the major urinary metabolite of prostaglandin F2 alpha was reduced by 67% in the propranolol-treated patients and by 57% in those receiving a thiazide diuretic. Body weight increased by 0 . 8 kg (propranolol) and 1 . 1 kg (thiazide diuretic) when indomethacin was given, but there were no significant changes in creatinine clearance, urinary sodium excretion, or packed cell volume in either treatment group. These results suggest that products formed by the arachidonic acid cyclo-oxygenase contribute to the regulation of blood pressure during treatment with both propranolol and thiazide diuretics. Inhibition of the cyclo-oxygenase with indomethacin partially antagonises the hypotensive effect of these drugs. 相似文献
119.
Abbott DE Pritchard C Clegg NJ Ferguson C Dumpit R Sikes RA Nelson PS 《Genome biology》2003,4(12):R79
Background
The prostate gland is an organ with highly specialized functional attributes that serves to enhance the fertility of mammalian species. Much of the information pertaining to normal and pathological conditions affecting the prostate has been obtained through extensive developmental, biochemical and genetic analyses of rodent species. Although important insights can be obtained through detailed anatomical and histological assessments of mouse and rat models, further mechanistic explanations are greatly aided through studies of gene and protein expression. 相似文献120.
Davide Danovi Amos Folarin Sabine Gogolok Christine Ender Ahmed M. O. Elbatsh P?r G. Engstr?m Stefan H. Stricker Sladjana Gagrica Ana Georgian Ding Yu Kin Pong U Kevin J. Harvey Patrizia Ferretti Patrick J. Paddison Jane E. Preston N. Joan Abbott Paul Bertone Austin Smith Steven M. Pollard 《PloS one》2013,8(10)
Glioblastoma multiforme (GBM) is the most common primary brain cancer in adults and there are few effective treatments. GBMs contain cells with molecular and cellular characteristics of neural stem cells that drive tumour growth. Here we compare responses of human glioblastoma-derived neural stem (GNS) cells and genetically normal neural stem (NS) cells to a panel of 160 small molecule kinase inhibitors. We used live-cell imaging and high content image analysis tools and identified JNJ-10198409 (J101) as an agent that induces mitotic arrest at prometaphase in GNS cells but not NS cells. Antibody microarrays and kinase profiling suggested that J101 responses are triggered by suppression of the active phosphorylated form of polo-like kinase 1 (Plk1) (phospho T210), with resultant spindle defects and arrest at prometaphase. We found that potent and specific Plk1 inhibitors already in clinical development (BI 2536, BI 6727 and GSK 461364) phenocopied J101 and were selective against GNS cells. Using a porcine brain endothelial cell blood-brain barrier model we also observed that these compounds exhibited greater blood-brain barrier permeability in vitro than J101. Our analysis of mouse mutant NS cells (INK4a/ARF−/−, or p53−/−), as well as the acute genetic deletion of p53 from a conditional p53 floxed NS cell line, suggests that the sensitivity of GNS cells to BI 2536 or J101 may be explained by the lack of a p53-mediated compensatory pathway. Together these data indicate that GBM stem cells are acutely susceptible to proliferative disruption by Plk1 inhibitors and that such agents may have immediate therapeutic value. 相似文献