全文获取类型
收费全文 | 90篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
99篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2001年 | 8篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 15 毫秒
21.
Binding of the MIG1 repressor to the glucose-repressible GAL1 and GAL4 promoters was analyzed in vivo by cyclobutane dimer footprinting in two yeast strains that show different glucose repression responses. Mig1p binding to the two promoters in both strains was glucose-induced. In cells subject to rapid and stringent glucose repression (S288c), long-term Mig1p binding in glucose-grown cells was inhibited by the formation of a competing chromatin structure. Under conditions where glucose repression was only partially effective (gal80 - or low glucose), the chromatin structure did not form and long-term Mig1p binding was observed The same long-term binding of Mig1p was seen in cells of a different strain (W303A) that shows only partial glucose repression of the GAL1 promoter. We conclude from these experiments that Mig1p binding to glucose-repressed promoters is glucose-dependent but transient. We suggest that Mig1p functions at an early step in repression, but is not required to maintain the repressed state. 相似文献
22.
Rosalba Lepore Andriy Kryshtafovych Markus Alahuhta Harshul A. Veraszto Yannick J. Bomble Joshua C. Bufton Alex N. Bullock Cody Caba Hongnan Cao Owen R. Davies Ambroise Desfosses Matthew Dunne Krzysztof Fidelis Celia W. Goulding Manickam Gurusaran Irina Gutsche Christopher J. Harding Marcus D. Hartmann Christopher S. Hayes Andrzej Joachimiak Petr G. Leiman Peter Loppnau Andrew L. Lovering Vladimir V. Lunin Karolina Michalska Ignacio Mir-Sanchis AK Mitra John Moult George N. Phillips Jr Daniel M. Pinkas Phoebe A. Rice Yufeng Tong Maya Topf Jonathan D. Walton Torsten Schwede 《Proteins》2019,87(12):1037-1057
The functional and biological significance of selected CASP13 targets are described by the authors of the structures. The structural biologists discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP13 experiment. 相似文献
23.
24.
Adults of the human parasitic trematode Schistosoma mansoni, which causes
hepatosplenic/intestinal complications in humans, synthesize
glycoconjugates containing the Lewis x (Lex) Galbeta1-->4(Fucalpha1--
>3)GlcNAcbeta1-->R, but not sialyl Lewis x (sLex), antigen. We now
report on our analyses of Lexand sLexexpression in S.haematobium and
S.japonicum, which are two other major species of human schistosomes that
cause disease, and the possible autoimmunity to these antigens in infected
individuals. Antigen expression was evaluated by both ELISA and Western
blot analyses of detergent extracts of parasites using monoclonal
antibodies. Several high molecular weight glycoproteins in both S.
haematobium and S. japonicum contain the Lexantigen, but no sialyl
Lexantigen was detected. In addition, sera from humans and rodents infected
with S.haematobium and S.japonicum contain antibodies reactive with Lex.
These results led us to investigate whether Lexantigens are expressed in
other helminths, including the parasitic trematode Fasciola hepatica , the
parasitic nematode Dirofilaria immitis (dog heartworm), the ruminant
nematode Haemonchus contortus , and the free-living nematode Caenorhabditis
elegans . Neither Lexnor sialyl-Lexis detectable in these other helminths.
Furthermore, none of the helminths, including schistosomes, express Lea,
Leb, Ley, or the H- type 1 antigen. However, several glycoproteins from all
helminths analyzed are bound by Lotus tetragonolobus agglutinin , which
binds Fucalpha1-->3GlcNAc, and Wisteria floribunda agglutinin, which
binds GalNAcbeta1-->4GlcNAc (lacdiNAc or LDN). Thus, schistosomes may be
unique among helminths in expressing the Lexantigen, whereas many different
helminths may express alpha1,3-fucosylated glycans and the LDN motif.
相似文献
25.
26.
27.
A high yield of nifedipine-chitosan microspheres could be obtained using an emulsification phase-separation method. A high level of entrapment of nifedipine in the microspheres was achieved. The microspheres exhibited excellent swelling properties. Differential scanning calorimetry, X-ray diffractometry, and scanning electron microscopy confirmed that at 1.84% loading, nifedipine was dispersed molecularly. The microspheres exhibited faster release at low loadings compared to high loadings. Fitting the data to the coupled Fickian/case II equation, showed that at low loadings polymer relaxation coefficients (k2) were high. As the polymer content increased in the microspheres, the value of n (diffusional exponent characteristic of the release mechanism) approached one, which is indicative of zero order. 相似文献
28.
Background
Clinical data, such as patient history, laboratory analysis, ultrasound parameters-which are the basis of day-to-day clinical decision support-are often used to guide the clinical management of cancer in the presence of microarray data. Several data fusion techniques are available to integrate genomics or proteomics data, but only a few studies have created a single prediction model using both gene expression and clinical data. These studies often remain inconclusive regarding an obtained improvement in prediction performance. To improve clinical management, these data should be fully exploited. This requires efficient algorithms to integrate these data sets and design a final classifier.LS-SVM classifiers and generalized eigenvalue/singular value decompositions are successfully used in many bioinformatics applications for prediction tasks. While bringing up the benefits of these two techniques, we propose a machine learning approach, a weighted LS-SVM classifier to integrate two data sources: microarray and clinical parameters.Results
We compared and evaluated the proposed methods on five breast cancer case studies. Compared to LS-SVM classifier on individual data sets, generalized eigenvalue decomposition (GEVD) and kernel GEVD, the proposed weighted LS-SVM classifier offers good prediction performance, in terms of test area under ROC Curve (AUC), on all breast cancer case studies.Conclusions
Thus a clinical classifier weighted with microarray data set results in significantly improved diagnosis, prognosis and prediction responses to therapy. The proposed model has been shown as a promising mathematical framework in both data fusion and non-linear classification problems. 相似文献29.
30.
Organization of mouse mammary tumor virus-specific DNA endogenous to BALB/c mice. 总被引:6,自引:15,他引:6 下载免费PDF全文
We used restriction endonucleases to prepare physical maps of the mouse mammary tumor virus (MMTV)-specific DNA endogenous to the BALB/c mouse strain. The mapping was facilitated by the DNA transfer procedure, using complementary DNAs specific for the whole and for the 3' terminus of MMTV RNA to detect fragments containing viral sequences. The strategies used for the arrangement of fragments into physical maps included sequential digestions with two or three enzymes; preparative isolation of EcoRI fragments containing viral sequences; and comparisons of virus-specific fragments derived from the DNA of several mouse strains. Most of the MMTV-related DNA in the BALB/c genome is organized into two units (II and III) which strongly resemble proviruses acquired upon horizontal infection with milk-borne strains of MMTV and other retroviruses. These units contain approximately 6.0 x 10(6) Mr of apparently uninterrupted viral sequences, they bear redundant sequences totaling at least 700 to 800 base pairs at their termini, and the terminal redundancies include sequences derived from the 3' end of MMTV RNA. Units II and III are closely related in that they share 12 of 14 recognition sites for endonucleases, but cellular sequences flanking units II and III are dissimilar by this criterion. The remainder of the MMTV-related DNA endogenous to BALB/c mice is found in a single subgenomic unit (unit I) with a complexity of ca. 2 x 10(6) Mr; the structure of this unit has not been further defined. These results support the hypotheses that endogenous proviruses have been acquired by infection of germinal tissues with MMTV. The physical maps are also useful for identifying the MMTV genomes endogenous to BALB/c mice in studies of the natural history of mammary tumorigenesis. 相似文献