全文获取类型
收费全文 | 423篇 |
免费 | 27篇 |
出版年
2023年 | 2篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2016年 | 5篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 35篇 |
2012年 | 21篇 |
2011年 | 33篇 |
2010年 | 19篇 |
2009年 | 17篇 |
2008年 | 39篇 |
2007年 | 29篇 |
2006年 | 20篇 |
2005年 | 23篇 |
2004年 | 29篇 |
2003年 | 36篇 |
2002年 | 16篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有450条查询结果,搜索用时 31 毫秒
1.
Multifunctional low-density lipoprotein (LDL) receptor-related protein 1 (LRP1) recognizes and internalizes a large number of diverse ligands, including LDL and factor VIII. However, little is known about the regulation of LRP1 endocytosis. Here, we show that a microtubule-based motor protein, KIF13B, in an unexpected and unconventional function, enhances caveolin-dependent endocytosis of LRP1. KIF13B was highly expressed in the liver and was localized on the sinusoidal plasma membrane of hepatocytes. KIF13B knockout (KO) mice showed elevated levels of serum cholesterol and factor VIII, and KO MEFs showed decreased uptake of LDL. Exogenous KIF13B, initially localized on the plasma membrane with caveolae, was translocated to the vesicles in the cytoplasm with LRP1 and caveolin-1. KIF13B bound to hDLG1 and utrophin, which, in turn, bound to LRP1 and caveolae, respectively. These linkages were required for the KIF13B-enhanced endocytosis of LRP1. Thus, we propose that KIF13B, working as a scaffold, recruits LRP1 to caveolae via LRP1–hDLG1–KIF13B–utrophin–caveolae linkage and enhances the endocytosis of LRP1. 相似文献
2.
Enzymatic desulfurization of dibenzothiophene by a cell-free system of Rhodococcus erythropolis D-1 总被引:1,自引:0,他引:1
Abstract Pseudomonas syringae cells were exposed to Cu2+ alone or in the precence of acetate, proline or cysteine, at concentrations that reduced free Cu2+ to 1/10 of the total copper. Ligand concentrations (designated as isoeffective) were determined experimentally using a Cu2+ -selective electrode and confirmed by computer calculations using published stability constants. Exposure of P. syringae cells to Cu2+ alone resulted in rapid and pronounced cell death, and binding of most of the copper in solution. The addition of acetate, proline or cysteine, a few minutes after Cu2+ treatment, resulted in a significant reduction in cell death, and in the amount of copper bound to the cells. For short exposures to Cu2+ , cysteine was more effective than acetate or proline, but after 60 min of treatment, similar results were observed with these ligands. The addition of ligands before Cu2+ resulted in even more reduced copper toxicity. The results showed that, at isoeffective concentrations, weak and moderate copper-ligands can effectively antagonize copper toxicity, and that this protective effect does not require previously equilibrated copper-ligand solutions and is not very dependent of the nature of the ligand. 相似文献
3.
Elfride De Baere Yoshimitsu Fukushima Kent Small Nitin Udar Guy Van Camp Kristien Verhoeven Aarno Palotie Anne De Paepe Ludwine Messiaen 《Genomics》2000,68(3):296
The blepharophimosis syndrome (BPES) is a rare genetic disorder characterized by blepharophimosis, ptosis, epicanthus inversus, and telecanthus. In type I, BPES is associated with female infertility, while in type II, the eyelid defect occurs by itself. The BPES syndrome has been mapped to 3q23. Previously, we constructed a YAC-, PAC-, and cosmid-based physical map surrounding the 3q23 translocation breakpoint of a t(3;4)(q23;p15.2) BPES patient, containing a 110-kb PAC (169-C 10) and a 43-kb cosmid (11-L 10) spanning the breakpoint. In this report, we present the identification of BPESC1 (BPES candidate 1), a novel candidate gene that is disrupted by the translocation on chromosome 3. Cloning of the cDNA has been performed starting from a testis-specific EST, AI032396, found in cosmid 11-L 10. The cDNA sequence of BPESC1 is 3518 bp in size and contains an open reading frame of 351 bp. No significant similarities with known proteins have been found in the sequence databases. BPESC1 contains three exons and spans a genomic fragment of 17.5 kb. Expression of BPESC1 was observed in adult testis tissue. We performed mutation analysis in 28 unrelated familial and sporadic BPES patients, but, apart from the disruption by the translocation, found no other disease-causing mutations. These data make it unlikely that BPESC1 plays a major role in the pathogenesis of BPES. 相似文献
4.
Dongdong Mu Manuel Montalbán-López Yoshimitsu Masuda Oscar P. Kuipers 《Applied and environmental microbiology》2013,79(14):4503-4508
Here, we report a new zinc-inducible expression system for Lactococcus lactis, called Zirex, consisting of the pneumococcal repressor SczA and PczcD. PczcD tightly regulates the expression of green fluorescent protein in L. lactis. We show the applicability of Zirex together with the nisin-controlled expression system, enabling simultaneous but independent regulation of different genes. 相似文献
5.
The defatted sclerotia powder was partially hydrolyzed with dilute acid, and the material obtained was fractionated by carbon column chromatography, separated into two disaccharides, three trisaccharides and three tetrasaccharides, respectively. In these hydrolyzates α, α-trehalose, Iaminaribiose, and gentiobiose were identified. 相似文献
6.
Takuro Nunoura Yoshihiro Takaki Hiromi Kazama Jungo Kakuta Shigeru Shimamura Hiroko Makita Miho Hirai Masayuki Miyazaki Ken Takai 《PloS one》2014,9(8)
Strain Hiromi 1, a sulfur-oxidizing gammaproteobacterium was isolated from a hydrothermal vent chimney in the Okinawa Trough and represents a novel genus that may include a phylogenetic group found as endosymbionts of deep-sea gastropods. The SSU rRNA gene sequence similarity between strain Hiromi 1 and the gastropod endosymbionts was approximately 97%. The strain was shown to grow both chemolithoautotrophically and chemolithoheterotrophically with an energy metabolism of sulfur oxidation and O2 or nitrate reduction. Under chemolithoheterotrophic growth conditions, the strain utilized organic acids and proteinaceous compounds as the carbon and/or nitrogen sources but not the energy source. Various sugars did not support growth as a sole carbon source. The observation of chemolithoheterotrophy in this strain is in line with metagenomic analyses of endosymbionts suggesting the occurrence of chemolithoheterotrophy in gammaproteobacterial symbionts. Chemolithoheterotrophy and the presence of homologous genes for virulence- and quorum sensing-related functions suggest that the sulfur-oxidizing chomolithotrophic microbes seek animal bodies and microbial biofilm formation to obtain supplemental organic carbons in hydrothermal ecosystems. 相似文献
7.
Yoshimitsu Yamazaki Hidekatsu Maeda 《Bioscience, biotechnology, and biochemistry》2013,77(11):3203-3213
One hundred and nineteen strains of microorganisms (yeasts, bacteria, actinomycetes and fungi) were screened as to the hydroxylation of bicyclo[2.2.1]heptane-7-carboxylic acid, bicyclo[2.2.1]hept-2-ene-7-syn-carboxylic acid, and their methyl esters. Several species belonging to the genera, Bacillus, Streptomyces, Penicillium, Aspergillus, Absidia, Beauveria, Cunninghamella, Drechslera, Mucor and Chaetomium, were found to asymmetrically hydroxylate some or all of the substrates. Bacillus thuringiensis and Aspergillus awamori were the most effective microorganisms for obtaining the chiral products, (lR)-2-hydroxy acids or esters, with enantiomeric purities of 75~90% e.e., which are potential intermediates for (?)-methyl jasmonate or natural prostaglandins. 相似文献
8.
9.
10.
Application of chimeric glucanase comprising mutanase and dextranase for prevention of dental biofilm formation 下载免费PDF全文
Ryoko Otsuka Susumu Imai Takatoshi Murata Yoshiaki Nomura Masaaki Okamoto Hideaki Tsumori Erika Kakuta Nobuhiro Hanada Yasuko Momoi 《Microbiology and immunology》2015,59(1):28-36
Water‐insoluble glucan (WIG) produced by mutans streptococci, an important cariogenic pathogen, plays an important role in the formation of dental biofilm and adhesion of biofilm to tooth surfaces. Glucanohydrolases, such as mutanase (α‐1,3‐glucanase) and dextranase (α‐1,6‐glucanase), are able to hydrolyze WIG. The purposes of this study were to construct bi‐functional chimeric glucanase, composed of mutanase and dextranase, and to examine the effects of this chimeric glucanase on the formation and decomposition of biofilm. The mutanase gene from Paenibacillus humicus NA1123 and the dextranase gene from Streptococcus mutans ATCC 25175 were cloned and ligated into a pE‐SUMOstar Amp plasmid vector. The resultant his‐tagged fusion chimeric glucanase was expressed in Escherichia coli BL21 (DE3) and partially purified. The effects of chimeric glucanase on the formation and decomposition of biofilm formed on a glass surface by Streptococcus sobrinus 6715 glucosyltransferases were then examined. This biofilm was fractionated into firmly adherent, loosely adherent, and non‐adherent WIG fractions. Amounts of WIG in each fraction were determined by a phenol‐sulfuric acid method, and reducing sugars were quantified by the Somogyi–Nelson method. Chimeric glucanase reduced the formation of the total amount of WIG in a dose‐dependent manner, and significant reductions of WIG in the adherent fraction were observed. Moreover, the chimeric glucanase was able to decompose biofilm, being 4.1 times more effective at glucan inhibition of biofilm formation than a mixture of dextranase and mutanase. These results suggest that the chimeric glucanase is useful for prevention of dental biofilm formation. 相似文献