全文获取类型
收费全文 | 247篇 |
免费 | 14篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 22篇 |
2012年 | 23篇 |
2011年 | 14篇 |
2010年 | 4篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 11篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1951年 | 1篇 |
1938年 | 1篇 |
1858年 | 1篇 |
排序方式: 共有261条查询结果,搜索用时 62 毫秒
211.
Patricia Renz Elias Imahorn Iris Spoerri Magomet Aushev Oliver P. March Hedwig Wariwoda Sarah Von Arb Andreas Volz Peter H. Itin Julia Reichelt Bettina Burger 《Journal of cellular and molecular medicine》2019,23(12):8442-8452
Ichthyosis with confetti (IWC) is a genodermatosis associated with dominant‐negative variants in keratin 10 (KRT10) or keratin 1 (KRT1). These frameshift variants result in extended aberrant proteins, localized to the nucleus rather than the cytoplasm. This mislocalization is thought to occur as a result of the altered carboxy (C)‐terminus, from poly‐glycine to either a poly‐arginine or ‐alanine tail. Previous studies on the type of C‐terminus and subcellular localization of the respective mutant protein are divergent. In order to fully elucidate the pathomechanism of IWC, a greater understanding is critical. This study aimed to establish the consequences for localization and intermediate filament formation of altered keratin 10 (K10) C‐termini. To achieve this, plasmids expressing distinct KRT10 variants were generated. Sequences encoded all possible reading frames of the K10 C‐terminus as well as a nonsense variant. A keratinocyte line was transfected with these plasmids. Additionally, gene editing was utilized to introduce frameshift variants in exon 6 and exon 7 at the endogenous KRT10 locus. Cellular localization of aberrant K10 was observed via immunofluorescence using various antibodies. In each setting, immunofluorescence analysis demonstrated aberrant nuclear localization of K10 featuring an arginine‐rich C‐terminus. However, this was not observed with K10 featuring an alanine‐rich C‐terminus. Instead, the protein displayed cytoplasmic localization, consistent with wild‐type and truncated forms of K10. This study demonstrates that, of the various 3′ frameshift variants of KRT10, exclusively arginine‐rich C‐termini lead to nuclear localization of K10. 相似文献
212.
213.
Titanium dental implants have been used successfully in implantology for more than 40 years. Recent research, however, suggests that titanium might have more side effects than previously believed. Zirconia ceramics have been employed in orthopaedic surgery for approximately 30 years and were recently introduced into dentistry as a metal replacement for crown and bridge work as well as implant abutments. Zirconium dioxide has been shown in both in vitro and in vivo studies to have desirable osseointegrative properties. This clinical study shows that dental implants made from zirconia are a feasible alternative to titanium dental implants. In addition to excellent cosmetic results, zirconia implants allow a degree of osseointegration and soft tissue response that is superior to titanium dental implants. 相似文献
214.
Two general classes of glycoproteins have been identified in the colonic epithelial cells of the Sprague Dawley rat. Glycoproteins belonging to the first of these classes contain sialic acids both with and without side chain o-acyl substituents, abundant o-sulphate ester and 'neutral sugars' (hexose, 6-deoxyhexose or N-acetyl hexosamine residues) with oxidisable vicinal diols and are located in the goblet cells of the descending colon and in goblet cells populating the upper halves of the crypts of the ascending colon. In the descending colon, the sulphosialoglycoproteins in the goblet cells in the base of the crypts contain sialic acids without side chain o-acyl substituents. It appears that as these cells migrate up the crypts, there is o-acylation of the side chains of the sialic acids of the glycoproteins and an increase in the quantity of 'neutral sugars' without a corresponding increase in sialic acid. Glycoproteins with similar properties to those of the goblet cells of the upper halves of the crypts of the descending colon, but containing less sulphate, are found in the goblet cells of the upper half of the crypts of the ascending colon. The second general class of glycoproteins contain sialic acids all, or almost all of which, are substituted at position C8 and only relatively small quantities of sulphate. They are located in the mucous cells of the descending colon, the deep crypt secretory cells of the ascending colon and the columnar absorptive cell brush border.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
215.
216.
Littoral zone marine sediment and sand, spiny lobster and conch were examined for yeasts. Nineteen yeast species were found to exist in varying abundance. Previous studies in the series examined the marine fungi (17), fresh water fungi (16), and keratinophilic fungi (15) of Abaco Island, The Bahamas. 相似文献
217.
Phosphoglycerides of Trichophyton terrestre and One Phenotype Selected from the Apollo 16 Microbial Ecology Evaluation Device
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Total lipid extracted from wild-type Trichophyton terrestre CDC-X285 was found to be 2.0 percent of the dry cell weight. The total lipid contained the following phospholipid components identified by silicic acid-impregnated thin-layer and paper chromatography: phosphatidyl inositol, phosphatidyl choline, phosphatidyl serine, and phosphatidic acid. The total lipid extracted from the phenotype T. terrestre 7048-1 isolated from the Apollo 16 Microbial Ecology Evaluation Device (MEED) was found to vary according to the time at which the phospholipids were extracted. The Trichophyton phenotype was selected from a cuvette housed in the MEED exposed to specific space parameters including ultraviolet light of known wavelengths and energy levels in deep space. The phospholipid components, identified in the phenotype were phosphatidyl ethanolamine and cardiolipin. The major lipid fraction was composed of digalactosyl diglyceride and monogalactosyl diglyceride. An unusual lipid was detected in the phenotype, which appeared to be sterol glycoside. 相似文献
218.
An expressed -tubulin gene (TUBB) has previously been localized to chromosome region 6pter-p21 in man. By using a panel of deletion mutant cell lines and radiation-reduced hybrids containing fragments of chromosome 6, the TUBB locus could be mapped to the HLA class I region at 6p21.3. A long range restriction map including TUBB and several HLA class I genes was then generated by rotating field gel electrophoresis. The results show that TUBB maps to a segment 170–370 kb telomeric of HLA-C. This location suggests that a mutation at the TUBB locus could be the cause for certain forms of HLAlinked microtubule dysfunction, including immotile cilia syndrome. 相似文献
219.
Tyrosine 106 of CheY plays an important role in chemotaxis signal transduction in Escherichia coli. 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
CheY is the response regulator in the signal transduction pathway of bacterial chemotaxis. Position 106 of CheY is occupied by a conserved aromatic residue (tyrosine or phenylalanine) in the response regulator superfamily. A number of substitutions at position 106 have been made and characterized by both behavioral and biochemical studies. On the basis of the behavioral studies, the phenotypes of the mutants at position 106 can be divided into three categories: (i) hyperactivity, with a tyrosine-to-tryptophan mutation (Y106W) causing increased tumble signaling but impairing chemotaxis; (ii) low-level activity, with a tyrosine-to-phenylalanine change (Y106F) resulting in decreased tumble signaling and chemotaxis; and (iii) no activity, with substitutions such as Y106L, Y106I, Y106V, Y106G, and Y106C resulting in no chemotaxis and a smooth-swimming phenotype. All three types of mutants can be phosphorylated by CheA-phosphate in vitro to a level similar to that of wild-type CheY. Autodephosphorylation rates are similar for all categories of mutants. All mutant proteins displayed less than twofold increased rates compared with wild-type CheY. Binding of the mutant proteins to FliM was similar to that of the wild-type CheY in the CheY-FliM binding assays. The combined results from in vivo behavioral and in vitro biochemical studies suggest that the diverse phenotypes of the Y106 mutants are not due to a variation in phosphorylation or dephosphorylation ability nor in affinity for the switch. With reference to the structures of wild-type CheY and the T871 CheY mutant, our results suggest that rearrangements of the orientation of the tyrosine side chain at position 106 are involved in the signal transduction of CheY. These data also suggest that the binding of phosphoryl-CheY to the flagellar motor is a necessary, but not sufficient, event for signal transduction. 相似文献
220.
Volz E 《Journal of mathematical biology》2008,56(3):293-310
Random networks with specified degree distributions have been proposed as realistic models of population structure, yet the
problem of dynamically modeling SIR-type epidemics in random networks remains complex. I resolve this dilemma by showing how
the SIR dynamics can be modeled with a system of three nonlinear ODE’s. The method makes use of the probability generating
function (PGF) formalism for representing the degree distribution of a random network and makes use of network-centric quantities
such as the number of edges in a well-defined category rather than node-centric quantities such as the number of infecteds
or susceptibles. The PGF provides a simple means of translating between network and node-centric variables and determining
the epidemic incidence at any time. The theory also provides a simple means of tracking the evolution of the degree distribution
among susceptibles or infecteds. The equations are used to demonstrate the dramatic effects that the degree distribution plays
on the final size of an epidemic as well as the speed with which it spreads through the population. Power law degree distributions
are observed to generate an almost immediate expansion phase yet have a smaller final size compared to homogeneous degree
distributions such as the Poisson. The equations are compared to stochastic simulations, which show good agreement with the
theory. Finally, the dynamic equations provide an alternative way of determining the epidemic threshold where large-scale
epidemics are expected to occur, and below which epidemic behavior is limited to finite-sized outbreaks.
相似文献