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排序方式: 共有187条查询结果,搜索用时 31 毫秒
21.
Dr. Tarja Kokkola Dr. Tiina Suuronen Dr. Maija Pesonen Prof. Panagis Filippakopoulos Dr. Antero Salminen Dr. Elina M. Jarho Dr. Maija Lahtela‐Kakkonen 《Chembiochem : a European journal of chemical biology》2015,16(14):1997-2001
Control of histone acetylation is a part of the epigenetic mechanism that regulates gene expression and chromatin architecture. The members of the bromodomain and extra terminal domain (BET) protein family are a group of epigenetic readers that recognize histone acetylation, whereas histone deacetyl‐ ases such as sirtuin 1 (SIRT1) function as epigenetic erasers. We observed that BET inhibition by the specific inhibitor JQ1 upregulated SIRT1 expression and activated SIRT1. Moreover, we observed that BET inhibition functionally reversed the pro‐inflammatory effect of SIRT1 inhibition in a cellular lung disease model. SIRT1 activation is desirable in many age‐related, metabolic and inflammatory diseases; our results suggest that BET protein inhibition would be beneficial in treatment of those conditions. Most importantly, our findings demonstrate a novel mechanism of SIRT1 activation by inhibition of the BET proteins. 相似文献
22.
An active single-chain antibody containing a cellulase linker domain is secreted by Escherichia coli
Takkinen Kristiina; Laukkanen Marja-Leena; Sizmann Dorothea; Alfthan Kaija; Immonen Tiina; Vanne Liisa; Kaartinen Matti; Knowles Jonathan K.C.; Teeri Tuula T. 《Protein engineering, design & selection : PEDS》1991,4(7):837-841
Single-chain antibodies consist of the variable, antigen-bindingdomains of antibodies joined to a continuous polypeptide bygenetically engineered peptide linkers. We have used the flexibleinterdomain linker region of a fungal cellulase to link togetherthe variable domains of an anti-2-phenyloxazolone IgGl and showhere that the resulting single-chain antibody is efficientlysecreted and released to the culture medium of Escherichia coli.The yield of affinity-purified single-chain antibody is 1 -2mg/1 of culture medium and its affinity and stability are comparableto those of the corresponding native IgG. 相似文献
23.
The purpose of this paper is to study optimal pricing in a mobile distributed network with transmit power control. The paper proposes a linear congestion pricing scheme for the optimal distributed control of a wireless network. The optimal congestion price applies for the optimal resource control in a congested communication network where decisions on resource usage are made locally by the mobile nodes applying a learning automaton. Numerical examples for the convergence of a price controlled wireless network to a Pareto-optimal transmit power allocation are presented. 相似文献
24.
This paper presents a review of existing analog implementations of the median and other ranked-order filter operations. The basic properties of median signal processing are first reviewed. Different analog median filter architectural approaches and implementations, introduced by several authors, are then discussed. These include filters based on analog delay lines and either nonlinear selection networks or ramp voltage generators. The Linear-Median Hybrid filter concept is presented and two examples of analog circuit implementations are given. Finally, a neural network approach is discussed. 相似文献
25.
Tiina Tamm 《Yeast (Chichester, England)》2009,26(1):55-66
A single‐step PCR‐based epitope tagging enables fast and efficient gene targeting with various epitope tags. This report presents a series of plasmids for the E2 epitope tagging of proteins in Saccharomyces cerevisiae and Schizosaccharomyces pombe. E2Tags are 10‐amino acids (epitope E2a: SSTSSDFRDR)‐ and 12 amino acids (epitope E2b: GVSSTSSDFRDR)‐long peptides derived from the E2 protein of bovine papillomavirus type 1. The modules for C‐terminal tagging with E2a and E2b epitopes were constructed by the modification of the pYM‐series plasmid. The N‐terminal E2a and E2b tagging modules were based on pOM‐series plasmid. The pOM‐series plasmids were selected for this study because of their use of the Cre–loxP recombination system. The latter enables a marker cassette to be removed after integration into the loci of interest and, thereafter, the tagged protein is expressed under its endogenous promoter. Specifically for fission yeast, high copy pREP plasmids containing the E2a epitope tag as an N‐terminal or C‐terminal tag were constructed. The properties of E2a and E2b epitopes and the sensitivity of two anti‐E2 monoclonal antibodies (5E11 and 3F12) were tested using several S. cerevisiae and Sz. pombe E2‐tagged strains. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
26.
Addition of nitrogen (N) to the field layer of boreal forests has been shown to increase the occurrence of the parasitic fungus Valdensia heterodoxa on Vaccinium myrtillus plants. We investigated whether N addition to soil alters the levels of polyamines in V. myrtillus shoots, and discuss here whether such changes could promote the spread of the parasitic fungus on V. myrtillus. Using HPLC, we analyzed the concentrations of free and conjugated polyamines in healthy and naturally V. heterodoxa-infected V. myrtillus plants, which had received a moderate or high dose of N fertilizer, or no additional N. Fertilization with N increased the concentrations of free diamines (putrescine and diaminopropane), but had no significant effect on conjugated amines. Thus, N-induced changes in the constitutive levels of soluble conjugated amines do not seem to explain the increased parasite susceptibility of V. myrtillus under N enrichment. Generally, the concentrations of free diamines and insoluble conjugated putrescine were higher in diseased than in healthy shoots, suggesting parasite-induced accumulation of diamines. Free spermine seemed to accumulate in unfertilized, diseased plants, but in fertilized plants this induction was dampened, suggesting that N-induced alterations in spermine metabolism may promote the spread of parasites on V. myrtillus under N-enrichment. 相似文献
27.
Tiina Vainio-Kaila Aino Kyyhkynen Pertti Viitaniemi Anja Siitonen 《Holz als Roh- und Werkstoff》2011,69(3):391-395
The survival of two bacteria, Escherichia coli and Listeria monocytogenes was observed on pine heartwood and glass surfaces by using a simple test method. The development of the number of bacterial cells was evaluated by titration after vortexing the samples in BHI broth and culturing the resulting broth on agar plates. The bacterial count decreased clearly faster on pine heartwood than on glass surfaces. This result was confirmed by studying the wooden samples also one day after to exclude possible adherence of the bacterial cells on the porous surface. This study confirms the results of several other studies that suggest wood to have antibacterial properties. 相似文献
28.
Fabien Cremona Alo Laas Toomas Kiv Margot Sepp Peeter Nges Tiina Nges 《Lakes & Reservoirs: Research and Management》2019,24(1):18-23
Theoretical pelagic primary production of phytoplankton and benthic primary production of periphyton were modelled for two small lakes in Estonia (Northeast Europe). Although located only 500 m apart, the water colour and light attenuation of these two lakes differed markedly. The Secchi depth (SD) in the clear‐water lake was 4.5 m and only 0.47 m in the dark‐water lake. The total phosphorus (TP) concentrations were, respectively, 15 μg/l and 28 μg/l. An empirical model whose inputs were morphometric, light conditions and dissolved organic carbon parameters obtained from in situ measurements was employed for the present study. The model calculated primary production with a time‐step of 10 min, and a spatial resolution of 10 cm, from sunrise to sunset and from lake surface to lake bottom. The primary production of periphyton and phytoplankton was almost equal in the clear lake, whereas only phytoplankton contributed to whole‐lake primary production in the dark lake because of the stronger light attenuation in the water column. The results of the present study indicated the depth‐distribution profiles differed dramatically between the two lakes. The clear lake had a deep, U‐shaped curve, with the productive layer reaching considerable depth soon after sunrise and maintaining a similar profile throughout the light hours. In contrast, the dark lake production declined rapidly with increasing depth, whereas the profile changed over the day reaching the greatest depth at noon. 相似文献
29.
Leiviskä T Nurmesniemi H Pöykiö R Rämö J Kuokkanen T Pellinen J 《Water research》2008,42(14):3952-3960
Pulp and paper mill wastewater was characterizated, before (influent) and after (effluent) biological wastewater treatment based on an activated sludge process, by microfiltration (8, 3, 0.45 and 0.22mum) and ultrafiltration (100, 50, 30 and 3kDa) of the wastewater samples into different size fractions. Various parameters were measured on each fraction: molecular weight distribution (MWD) using high performance size exclusion chromatography (HPSEC), total organic carbon (TOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), phosphate phosphorus (PO(4)-P), electrical conductivity, pH, turbidity, charge quantity and zeta potential. The MWD, TOC and COD(Cr) results indicated that the majority of the material present in both the influent and effluent was in the medium molecular weight (MW) range (i.e. MW<10kDa) with three main MW sub-fractions. There were no significant differences in the range of the MWD between the influent and effluent samples. The magnitude of the MWD in the effluent was about one half that in the influent, the greatest reduction being in the 6kDa fraction. The 3kDa fractions of both the influent and effluent showed a considerable increase in BOD(7), probably due to the removal of compounds harmful to bacteria in 3kDa ultrafiltration. Influent turbidity decreased considerably in microfiltration (8-0.22mum). As the turbidity was removed by 0.22mum filtration, the anionic charge quantity started to decrease. Particles in the influent and effluent contained 19-29% and 14-20% of the total phosphorus, respectively. The major phosphorus fraction was in the form of soluble phosphate. 相似文献
30.
Pól J Kauppila TJ Haapala M Saarela V Franssila S Ketola RA Kotiaho T Kostiainen R 《Analytical chemistry》2007,79(9):3519-3523
The first microchip version of sonic spray ionization (SSI) as an atmospheric pressure ionization source for mass spectrometry (MS) is presented. The microchip used for SSI has recently been developed in our laboratory, and it has been used before as an atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) source. Now the ionization is achieved simply by applying high (sonic) speed nebulizer gas, without heat, corona discharge, or high voltage. The microchip SSI was applied to the analysis of tetra-N-butylammonium, verapamil, testosterone, angiotensin I, and ibuprofen. The limits of detection were in the range of 15 nM to 4 microM. The technique was found to be highly dependent on the position of the chip toward the mass spectrometer inlet, and on the gas and the sample solution flow rates. The microchip SSI provided dynamic linearity following a pattern similar to that used with electrospray, good quantitative repeatability (RSD=16%), and long-term signal stability. 相似文献