40,668 research outputs found
The granulocytic inducer C/EBPalpha inactivates the myeloid master regulator PU.1
No full textVerschiedene Transkriptionsfaktoren spielen eine Rolle in der Entwicklung myeloischer Zellen. PU.1, ein Transkriptionsfaktor aus der ETS-Familie, ist sowohl für die Entwicklung lymphatischer als auch für die Entwicklung myeloischer Zellen von Bedeutung. Der Transkriptions
faktor C/EBPalpha, ein an den CCAAT-Enhancer bindendes Protein, ist hingegen wesentlich verantwortlich für die Entwicklung von Granulozyten. Wir stellen hier den ersten Nachweis dafür vor, dass C/EBPalpha die Funktion von PU.1 blockiert. PU.1 und C/EBPalpha können einander binden und sind in myeloischen Zellen kolokalisiert. Wenn C/EBPalpha PU.1 bindet, kann PU.1 einen minimalen Promotor mit Bindungsstelle für PU.1 nicht mehr aktivieren. Wir zeigen, dass der Leuzin-Zipper in der DNA-bindenden Domäne von C/EBPalpha mit der beta3/beta4-Region in der DNA-bindenden Domäne von PU.1 interagieren kann. Dadurch wird der Koaktivator von PU.1, c-jun, aus seiner Bindung mit PU.1 verdrängt. C/EBPalpha hemmt PU.1 nicht, indem es Korepressoren rekrutiert. Vielmehr vermindert C/EBPalpha die Expression von PU.1 in U-937-Zellen mit induzierbarem C/EBPalpha, indem es den autoregulatorischen Effekt PU.1 auf den PU.1-Promotor hemmt.
Ausserdem blockiert C/EBPalpha die durch PU.1 bedingte Entwicklung dendritischer Zellen aus CD34+ menschlichen Nabel blutzellen. Diese funktionelle Blockade von PU.1 durch C/EBPalpha könnte einer der Mechanismen sein, mit denen C/EBPalpha den durch PU.1 determinierten Weg der Zelldifferenzierung hemmt und sich Zellen unter dem Einfluss von C/EBPalpha zu Granulozyten entwickeln.Several transcription factors have been shown to play a role in myelopoiesis. PU.1, an ets-family transcription factor, is required for the development of both myeloid and lymphoid lineages while the transcription factor CCAAT/enhancer binding protein family member C/EBPalpha is essential for granulocytic development. We present here the first evidence that C/EBPalpha blocks the function of PU.1. PU.1 and C/EBPalpha interact physically and co-localize in myeloid cells. As a consequence of this interaction C/EBPalpha can inhibit the function of PU.1 to activate a minimal promoter containing only PU.1 DNA binding sites. We further demonstrate that the leucine zipper in the DNA binding domain of C/EBPalpha interacts with the beta3/beta4 region in the DNA binding domain of PU.1, and as a result displaces the PU.1 co-activator c-Jun. Finally, C/EBPalpha blocks PU.1 induced dendritic cell development from CD34+ human cord blood cells. The functional blocking of PU.1 by C/EBPalpha could be the mechanism by which C/EBPalpha inhibits the cell fates specified by PU.1, and directs cell development to the granulocytic lineage
Recall this Book 14: In Focus: Cixin Liu
No full textIn this episode, John and Brandeis professor Pu Wang talk with the bestselling science fiction author Cixin Liu. Mr. Liu is the author of The Three Body Problem, The Dark Forest, Death's End, and other works. When he visited Brandeis to receive an honorary degree, Liu paid a visit to the RTB lair to record this interview. He spoke in Chinese and Pu translated his remarks in this English version of the interview: if you would rather listen to the original Chinese conversation, you will find it on the RTB website and in your podcast stream (see Episode 14c). They discuss the evolution of Mr. Liu's science fiction fandom, and the powerful influence of Leo Tolstoy on Mr. Liu's work, which leads to a consideration of realism and its relationship to science fiction. Science fiction is also compared and contrasted with myth, mathematics, and technology. Lastly, they consider translation, and the special capacity that science fiction has to emerge through the translation process relatively unscathed. This is a testament to science fiction's taking as its subject the affairs of the whole human community-compared to the valuable but distinctly Chinese concerns of Mo Yan, or the distinctly Russian concerns of Tolstoy
Li han lin quan ji: si shi er juan, mu lu si juan, nian pu. v.1
No full text[李白].綫裝, 1函.框20.3x14.8公分, 9行18字, 小字雙行同. 白口, 左右雙邊, 單白魚尾. 版心中鐫"李集"及卷次, 下鐫葉次.書根印有"李翰林集"前有王樨登序, 李陽冰《李翰林詩序》, 樂史《別集序》, 宋敏求後序, 曾鞏後序, 毛漸題跋.書中樂史《別集序》載"李翰林歌詩李陽冰纂為草堂集十卷史又別收歌詩十卷與草堂集互有得失因校勘排為二十卷號曰李翰林集"With: 李翰林年譜 / 薛仲邕編 ; 舊唐書列傳 ; 新唐書列傳 ; 李翰林墓誌銘 / 李華 ; 碣記 / 劉全 ; 碑陰記 / 蘇軾.Xian zhuang, 1 han.Kuang 20.3 x 14.8 gong fen, 9 hang 18 zi, xiao zi shuang hang tong. Bai kou, zuo you shuang bian, dan bai yu wei. Ban xin zhong juan "Li ji"ji juan ci, xia juan ye ci.Shu gen yin you "Li han lin ji"Qian you Wang Xideng xu, Li Yangbing "Li han lin shi xu", Yue Shi "Bie ji xu", Song Minqiu hou xu, Zeng Gong hou xu, Mao Jian ti ba.Shu zhong Yue Shi "Bie ji xu" zai "Li han lin ge shi Li Yangbing zuan wei Cao tang ji shi juan shi you bie shou ge shi shi juan yu Cao tang ji hu you de shi yin jiao kan pai wei er shi juan hao yue Li han lin ji"[Li Bai].With: Li han lin nian pu / Xue Zhongyong bian ; Jiu Tang shu lie zhuan ; Xin Tang shu lie zhuan ; Li han lin mu zhi ming / Li Hua ; Jie ji / Liu Quan ; Bei yin ji / Su Shi
Influence of the height of carbon nanotubes on hot switching of Au/Cr-Au/MWCNT contact pairs
No full textGold coated Multi-Walled Carbon Nanotube (MWCNT) composites have been used for electrical contact surfaces in previous studies. It was shown that the composite could significantly improve switch lifetime, and exhibited potential as a useful contact material for MEMS switches. The reason is attributed to the contribution of the compressibility of the MWCNT forest, which creates a compliant layer under the gold films. In this study, experiments were performed for samples with different heights of MWCNT forests, namely 30 µm, 50 µm and 80 µm. The influence of MWCNT height on the switching behavior and lifetime were studied. An outcome of the work was that the sample with 80 µm height forests showed the longest lifetime, however the composites with 30 µm and 50 µm forest heights showed lower contact resistances, a parameter of high importance for MEMS switch applications
Liu Kang
No full textLiu Kang: Essays on Art and Culture is a testament to the inexorable passion of an artist who knew no boundaries. This collection of essays, which Liu Kang wrote over 44 years, offers an insight into the artist’s myriad interests as well as his contributions as a first generation Nanyang artist and art educator. Translated into English for this volume, Liu Kang’s essays are accompanied by commentaries and photographs of the artist-author and his subjects
Nan fang qi di: qi chang hua ju.
No full text南方汽笛 /濮思溫, 劉振烝, 羅國良編劇濮思溫, 劉振烝, 羅國良編劇.Pu Siwen, Liu Zhencheng, Luo Guoliang bian ju
Mechanical characterization of a Au coated carbon nanotube multi-layered structure
No full textMultiwalled Carbon Nanotube (MWCNT) -coated surfaces have been proved to be able to provide stable resistance for the electrical contact under low force conditions since they can offer a compliant support for the conducting gold layer. However, the contact mechanics of the Au/MWCNTs composite have not been understood. In this study, a finite element multi-layered contact model was developed, in which the top layer was modeled as a composite and under layer was modeled as CNT forest. The study shows that this complex surface is best modeled as a multi-layered structure. The model is optimized and validated with nano-indenter data. The model can help to better understand the structure and material properties of Au/CNTs surfaces, and can provide guidance to optimize the surface in terms of contact resistance performance in MEMS switches
Pu-erh Tea Restored Circadian Rhythm Disruption by Regulating Tryptophan Metabolism
No full textPu-erh tea is a healthy beverage
rich in phytochemicals, and its
effect on the risk of inducing circadian rhythm disorders (CRD) is
unclear. In this study, healthy mice were given water or 0.25% (w/v)
Pu-erh tea for 7 weeks, followed by a 40 day disruption of the light/dark
cycle. CRD caused dysregulation of neurotransmitter secretion and
clock gene oscillations, intestinal inflammation, and disruption of
intestinal microbes and metabolites. Pu-erh tea boosted the indole
and 5-hydroxytryptamine pathways of tryptophan metabolism via the
gut–liver–brain axis. Furthermore, its metabolites (e.g.,
IAA, Indole, 5-HT) enhanced hepatic glycolipid metabolism and down-regulated
intestinal oxidative stress by improving the brain hormone release.
Tryptophan metabolites and bile acids also promoted liver lipid metabolism
and inhibited intestinal inflammation (MyD88/NF-κB) via the
enterohepatic circulation. Collectively, 0.25% (w/v) Pu-erh tea has
the potential to prevent CRD by promoting indole and 5-HT pathways
of tryptophan metabolism and signaling interactions in the gut–liver–brain
axis
Thermodynamic modeling of the Mg-Pu and Cu-Pu systems
No full text通讯作者地址: Liu, XJ (通讯作者), Xiamen Univ, Dept Mat Sci & Engn, Coll Mat, Xiamen 361005, Peoples R China
地址:
1. Xiamen Univ, Dept Mat Sci & Engn, Coll Mat, Xiamen 361005, Peoples R China
2. Xiamen Univ, Res Ctr Mat Design & Applicat, Xiamen 361005, Peoples R China
电子邮件地址: [email protected] thermodynamic assessment of the Mg-Pu and Cu-Pu systems was carried out by using the calculation of phase diagrams (CALPHAD) method on the basis of experimental data including thermodynamic properties and phase equilibria. The Gibbs free energies of the liquid, fcc, hcp, alpha Pu, beta Pu, gamma Pu, delta Pu, delta'Pu, and epsilon Pu phases were described by the subregular solution model with a Redlich-Kister equation, and those of the intermetallic compounds in the Mg-Pu and Cu-Pu binary systems were described by the sublattice model. A consistent set of thermodynamic parameters were derived for describing the Gibbs free energies of solution phases and intermetallic compounds in the Mg-Pu and Cu-Pu binary systems. An agreement between the calculated results and experimental data is obtained. (C) 2009 Elsevier B.V. All rights reserved.National Natural Science Foundation of China 50425101
5077108
Estudo de matrizes elastoméricas de borracha natural e PU/PBDO para aplicação tecnológicas
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2014.Esta tese de doutorado aborda estudos relativos à síntese e caracterização de sistemas elastoméricos de borracha natural e uretano/uréia (PU/PBDO) visando aplicações tecnológicas. Foram investigados diferentes compósitos e/ou sistemas elastoméricos. Sendo caracterizado em função da relação elastômero/dopante e/ou funcionalizações específicas. Assim, cada trabalho seguiu objetivos específicos bem definidos para cada compósito e/ou sistema produzido. Dessa forma podemos dividir os trabalhos em dois grandes grupos, um baseado em amostras contendo a borracha natural outro para amostras produzidas com PU/PBDO. Para o grande grupo da borracha natural, investigou-se o efeito de relaxação inversa em filmes finos dopados com moléculas de azocorante produzidos por casting e submetidos ao processo de fotoalinhamento, onde as anisotropias do substrato combinadas ao processo de secagem produzem a orientação das cadeias poliméricas. Em outro trabalho foram investigados os efeitos de diferentes solventes orgânicos na morfologia de membranas de borracha natural utilizando microscopia de força atômica e análises de leis de escala, onde processos experimentais permitiram obter membranas com baixa rugosidade e/ou altamente rugosas, além disso, uma relação da morfologia com a volatilidade dos solventes foi proposta. Visando propósitos biomédicos, blendas de borracha natural com fosfatos de cálcio (Ca/P) foram produzidas e investigadas, onde buscou-se combinar técnicas experimentais de purificação do processo de centrifugação do látex e incorporação de partículas de Ca/P no volume da matriz de borracha. Neste estudo foram analisadas as interações entre proteínas, na forma de vesículas, remanescentes do látex e partículas de Ca/P, onde verificou-se que as partículas de Ca/P são envolvidas pelas vesículas de proteínas dispersas no volume da matriz polimérica. As propriedades ópticas de membranas de borracha natural, pura e dopada com moléculas orgânicas luminescentes, bem como, a produção por eletrofiação de fibras altamente paralelas com diâmetros micro e sub-micrométricos de borracha natural pura e dopada com luminescente também foram investigadas. Por fim, a fabricação e caracterização de eletrodos elastoméricos pela deposição de nanotubos de carbono, por spray ultrassônico, sobre ?substratos? de borracha natural foram estudadas.Para o sistema elastomérico PU/PBDO realizamos os estudos dasxivpropriedades ópticas, morfológicas e mecânicas para membranas dopadas com diferentes moléculas luminescentes, onde a birrefringência para a membrana pura e a emissão polarizada de um luminescente específico para uma membrana dopada foram testadas em função do alinhamento da matriz polimérica devido a deformação mecânica. Esferas luminescentes com uma face enrugada e outra lisa, chamadas de esferas Janus luminescentes, foram produzidas para o sistema PU/PBDO dopado com Alq3 e caracterizadas via técnicas de microscopia (força atômica, eletrônica de varredura e luminescência óptica) e espectroscopia UV-Vis, além disso, para esse mesmo sistema esferas luminescentes micrométricas foram produzidas pela técnica de microfluídica, onde, para ambos os estudos, o controle das condições experimentais foi alcançado. Por fim, a produção e as caracterizações ópticas de esferas de PU/PBDO luminescentes dopadas com diferentes compostos emissores foram investigadas.Abstract : This PhD thesis report the studies carried using as elastomeric materials the natural rubber (NR) and the urethane/urea synthetic elastomer (polyurethane/polybutadienediol - PU/PBDO) for technological applications. Different composites and/or elastomeric systems were investigated and characterized according to the specific elastomer/dopant system and/or due to their added functionalizations. Therefor, this study followed a specific well-defined objectives for each composite system produced. In this way we can divide this PhD thesis in two large groups, one based on samples containing natural rubber and another for samples produced with PU / PBDO. For the large group of natural rubber, we investigated the effect of inverse relation in thin films doped with azo-dye molecules produced by casting and subjected to photoalignment process. Where the anisotropy of the substrates combined with the drying process produces the orientation on the polymer chains. In another study we investigate the effects in the morphology for natural rubber membranes produced using different organic solvents. For this analyses we used the atomic force microscopy (AFM) combinated with scaling laws. This investigation allowed the achievement of membranes with low and/or high roughness. Moreover, we propose the dependence of the morphology due to the volatility of the solvents. In other study, blends of NR with calcium/phosphorous compounds (NR-Ca/P) were produced to be used in biomedical applications. In this study the interactions between NR protein-particles with pseudomicellar form that are remained after latex centrifugation process and Ca/P particles were investigated. Confocal laser scanning microscopy was used to observe these interactions and we can see that the Ca/P particles are involved by the NR protein-particles dispersed in the polymer matrix and a model was proposed to explain that. Optical properties of natural rubber membranes undoped and doped with luminescent organic molecules were investigated. Moreover, highly parallel fibers with diameters in the micro and sub-micrometer range produced by electrospinning from NR solutions undoped and doped with luminescent were also investigated. Finally, were studied the fabrication of elastomeric electrodes produced using NR membranes as substrate and depositing single-walled carbon nanotubes (SWNT) by ultrasonic spray deposition.xviFor the large group of PU/PBDO elastomeric system, we have studied the optical, mechanical and morphological properties of PU/PBDO membranes undoped and doped with luminescent organic molecules. The polarized photoemission for PU/PBDO luminescent membranes were tested on function of the polymer matrix alignment by mechanical deformation. In another study, we investigate the production of luminescent spheres with tuned surface, where one side was wrinkled and other has remained smooth. This spheres are called luminescent Janus spheres and were produced from PU/PBDO system doped with Alq3. Morphological and optical properties were characterized, being determinated the best parameters of the Janus obtention. In addition, micrometer spheres were produced from the same PU/PBDO-Alq3 system using the microfluidics technique, where the diameter sizes of this spheres were changed adjusting the experimental conditions. Finally, we investigate others luminescent compounds for production of new luminescent PU/PBDO spheres
- …
