全文获取类型
收费全文 | 288篇 |
免费 | 42篇 |
出版年
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 10篇 |
2010年 | 12篇 |
2009年 | 15篇 |
2008年 | 18篇 |
2007年 | 12篇 |
2006年 | 7篇 |
2005年 | 22篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1969年 | 4篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 3篇 |
1962年 | 2篇 |
1961年 | 1篇 |
1960年 | 2篇 |
排序方式: 共有330条查询结果,搜索用时 15 毫秒
1.
Citrate synthase (E.C. 4.1.3.7) has been isolated from bean mitochondria by an improved procedure. The purified enzyme had a specific activity of 50. In most respects (e.g. sedimentation constant, Kms, pH sensitivity and ionic strength inhibition) the enzyme is similar to that prepared from mammalian sources. The feature distinguishing the plant enzyme from the others was its inhibition by several sulfhydryl reagents. The substrates conferred either complete protection (acetyl coenzyme A) or partial protection (oxalacetic acid) against the inhibition. Dithiothreitol (DTT) was capable of partially reversing the inhibition. The efficacy of DTT varied with the sulfhydryl reagent and was inversely related to the period of incubation of the enzyme with the reagent. 相似文献
2.
Marcia Divoll David J. Greenblatt 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1981,222(1):125-128
A simple and sensitive high-performance liquid chromatographic assay of methotrexate (MTX) and its two active metabolites, 7-hydroxymethotrexate (7-OH-MTX) and 2,4-di-amino-N10-methylpteroic acid (APA) in plasma, saliva and urine was developed. The method involved deproteinization with acetonitrile followed by addition of isoamyl alcohol and ethyl acetate. After extraction the sample was chromatographed on a cation-exchange column and monitored at 313 nm. The retention times were 5, 7 and 9 min and detection limits 20, 10 and 5 ng/ml for 7-OH-MTX, MTX and APA, respectively. For concentrations greater than 100 ng/ml one-step deproteinization of 0.1 ml sample with 0.25 ml acetonitrile was satisfactory for sample preparation. The method has been evaluated in samples from patients and rabbits receiving MTX. 相似文献
3.
4.
Carney D. Matheson Kim K. Vernon Arlene Lahti Renee Fratpietro Mark Spigelman Shimon Gibson Charles L. Greenblatt Helen D. Donoghue 《PloS one》2009,4(12)
The Tomb of the Shroud is a first-century C.E. tomb discovered in Akeldama, Jerusalem, Israel that had been illegally entered and looted. The investigation of this tomb by an interdisciplinary team of researchers began in 2000. More than twenty stone ossuaries for collecting human bones were found, along with textiles from a burial shroud, hair and skeletal remains. The research presented here focuses on genetic analysis of the bioarchaeological remains from the tomb using mitochondrial DNA to examine familial relationships of the individuals within the tomb and molecular screening for the presence of disease. There are three mitochondrial haplotypes shared between a number of the remains analyzed suggesting a possible family tomb. There were two pathogens genetically detected within the collection of osteological samples, these were Mycobacterium tuberculosis and Mycobacterium leprae. The Tomb of the Shroud is one of very few examples of a preserved shrouded human burial and the only example of a plaster sealed loculus with remains genetically confirmed to have belonged to a shrouded male individual that suffered from tuberculosis and leprosy dating to the first-century C.E. This is the earliest case of leprosy with a confirmed date in which M. leprae DNA was detected. 相似文献
5.
Sanjiv M. Baxi Ruth M. Greenblatt Peter Bacchetti Chengshi Jin Audrey L. French Marla J. Keller Michael H. Augenbraun Stephen J. Gange Chenglong Liu Wendy J. Mack Monica Gandhi Women’s Interagency HIV Study 《PloS one》2015,10(6)
Effective antiretroviral (ARV) therapy depends on adequate drug exposure, yet methods to assess ARV exposure are limited. Concentrations of ARV in hair are the product of steady-state pharmacokinetics factors and longitudinal adherence. We investigated nevirapine (NVP) concentrations in hair as a predictor of treatment response in women receiving ARVs. In participants of the Women’s Interagency HIV Study, who reported NVP use for >1 month from 2003–2008, NVP concentrations in hair were measured via liquid-chromatography-tandem mass-spectrometry. The outcome was virologic suppression (plasma HIV RNA below assay threshold) at the time of hair sampling and the primary predictor was nevirapine concentration categorized into quartiles. We controlled for age, race/ethnicity, pre-treatment HIV RNA, CD4 cell count, and self-reported adherence over the 6-month visit interval (categorized ≤ 74%, 75%–94% or ≥ 95%). We also assessed the relation of NVP concentration with changes in hepatic transaminase levels via multivariate random intercept logistic regression and linear regression analyses. 271 women contributed 1089 person-visits to the analysis (median 3 of semi-annual visits). Viral suppression was least frequent in concentration quartile 1 (86/178 (48.3%)) and increased in higher quartiles (to 158/204 (77.5%) for quartile 4). The odds of viral suppression in the highest concentration quartile were 9.17 times (95% CI 3.2–26, P < 0.0001) those in the lowest. African-American race was associated with lower rates of virologic suppression independent of NVP hair concentration. NVP concentration was not significantly associated with patterns of serum transaminases. Concentration of NVP in hair was a strong independent predictor of virologic suppression in women taking NVP, stronger than self-reported adherence, but did not appear to be strongly predictive of hepatotoxicity. 相似文献
6.
7.
JF Yuan SJ Zhang O Jafer RA Furlong OE Chausiaux CA Sargent GH Zhang NA Affara 《BMC microbiology》2009,9(1):246
Background
Pseudorabies virus (PRV) is an alphaherpesviruses whose native host is pig. PRV infection mainly causes signs of central nervous system disorder in young pigs, and respiratory system diseases in the adult. 相似文献8.
Background
Most studies examining the commensal human oral microbiome are focused on disease or are limited in methodology. In order to diagnose and treat diseases at an early and reversible stage an in-depth definition of health is indispensible. The aim of this study therefore was to define the healthy oral microbiome using recent advances in sequencing technology (454 pyrosequencing). 相似文献9.
Jae-Hyuck Shim Matthew B Greenblatt Min Xie Michael D Schneider Weiguo Zou Bo Zhai Steven Gygi Laurie H Glimcher 《The EMBO journal》2009,28(14):2028-2041
TGFβ activated kinase 1 (TAK1), a member of the MAPKKK family, controls diverse functions ranging from innate and adaptive immune system activation to vascular development and apoptosis. To analyse the in vivo function of TAK1 in cartilage, we generated mice with a conditional deletion of Tak1 driven by the collagen 2 promoter. Tak1col2 mice displayed severe chondrodysplasia with runting, impaired formation of secondary centres of ossification, and joint abnormalities including elbow dislocation and tarsal fusion. This phenotype resembled that of bone morphogenetic protein receptor (BMPR)1 and Gdf5-deficient mice. BMPR signalling was markedly impaired in TAK1-deficient chondrocytes as evidenced by reduced expression of known BMP target genes as well as reduced phosphorylation of Smad1/5/8 and p38/Jnk/Erk MAP kinases. TAK1 mediates Smad1 phosphorylation at C-terminal serine residues. These findings provide the first in vivo evidence in a mammalian system that TAK1 is required for BMP signalling and functions as an upstream activating kinase for Smad1/5/8 in addition to its known role in regulating MAP kinase pathways. Our experiments reveal an essential role for TAK1 in the morphogenesis, growth, and maintenance of cartilage. 相似文献
10.