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LiYF_(4):Yb/LiYF_(4) and LiYF_(4):Yb,Er/LiYF_(4) core/shell nanocrystals with luminescence decay times similar to YLF laser crystals and the upconversion quantum yield of the Yb,Er doped nanocrystals

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Nano Research 2021年第3期14卷 797-806页

作者： Frederike Carl Leonie Birk bettina Grauel Monica Pons Christian Würth Ute Resch-Genger Markus Haase Institute of Chemistry of New Materials Department Biology/ChemistryUniversity OsnabrueckBarbarastr.749076OsnabrueckGermany Division 1.2 Biophotonics Federal Institute for Materials Research and Testing(BAM)Richard-Willstaetter-Str.1112489BerlinGermany

We developed a procedure to prepare luminescent LiYF_(4):Yb/LiYF_(4) and LiYF_(4):Yb,Er/LiYF_(4) core/shell nanocrystals with a size of approximately 40 nm revealing luminescence decay times of the dopant ions that approach those of high-quality laser crystals of LiYF_(4):Yb(Yb:YLF)and LiYF_(4):Yb,Er(Yb,Er:YLF)with identical doping *** the luminescence decay times of Yb^(3+)and Er^(3+)are known to be very sensitive to the presence of quenchers,the long decay times of the core/shell nanocrystals indicate a very low number of defects in the core particles and at the core/shell *** improvement in the performance was achieved by introducing two important modifications in the commonly used oleic acid based ***,the shell was prepared via a newly developed method characterized by a very low nucleation rate for particles of pure LiYF_(4) shell ***,anhydrous acetates were used as precursors and additional drying steps were applied to reduce the incorporation of OH−in the crystal lattice,known to quench the emission of Yb^(3+)*** power density(P)-dependent absolute measurements of the upconversion luminescence quantum yield(ΦUC)of LiYF_(4):Yb,Er/LiYF_(4) core/shell particles reveal a maximum value of 1.25%at P of 180 W·cm^(−2).Although lower than the values reported for NaYF4:18%Yb,2%Er core/shell nanocrystals with comparable sizes,theseΦUC values are the highest reported so far for LiYF_(4):18%Yb,2%Er/LiYF_(4) nanocrystals without additional *** improvements may nevertheless be possible by optimizing the dopant concentrations in the LiYF_(4) nanocrystals.

关键词： nanocrystal decay time luminescence LiYF_(4) quantum yield upconversion

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Wound-Induced Shoot-to-Root Relocation of JA-Ile Precursors Coordinates Arabidopsis Growth

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Molecular Plant 2019年第10期12卷 1383-1394页

作者： Adina Schulze Marlene Zimmer Stefan Mielke Hagen Stellmach Charles WMelnyk bettina Hause Debora Gasperini Department of Molecular Signal Processing Leibniz Institute of Plant BiochemistryWeinberg 306120 Halle(Saale)Germany Department of Cell and Metabolic Biology Leibniz Institute of Plant Biochemistry06120 Halle(Saale)Germany Department of Plant Biology.Swedish University of Agricultural Sciences 75651 UppsalaSweden

Multicellular organisms rely on the movement of signaling molecules across cells,tissues,and organs to communicate among distal *** plants,localized leaf damage activates jasmonic acid(JA)-dependent transcriptional reprogramming in both harmed and unharmed *** it has been indicated that JA species can translocate from damaged into distal sites,the identity of the mobile compound(s),the tissues through which they translocate,and the effect of their relocation remain ***,we found that following shoot wounding,the relocation of endogenous jasmonates through the phloem is essential to initiate JA signaling and stunt growth in unharmed roots of Arabidopsis *** employing grafting experiments and hormone profiling,we uncovered that the hormone precursor cis-12-oxo-phytodienoic acid(OPDA)and its derivatives,but not the bioactive JA-Ile conjugate,translocate from wounded shoots into undamaged *** root relocation,the mobile precursors cooperatively regulated JA responses through their conversion into JA-Ile and JA signaling ***,our findings demonstrate the existence of long-distance translocation of endogenous OPDA and its derivatives,which serve as mobile molecules to coordinate shoot-to-root responses,and highlight the importance of a controlled redistribution of hormone precursors among organs during plant stress acclimation.

关键词： grafting jasmonate OPDA phloem phytohormone

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Self-expanding metal stents for the palliation of malignant gastric outlet obstruction in patients with peritoneal carcinomatosis

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World Journal of Gastroenterology 2016年第43期22卷 9554-9561页

作者： Christoph Rademacher Matthias Bechtler Steffen Schneider bettina Hartmann Johannes Striegel Ralf Jakobs Medizinische Klinik C Klinikum der Stadt Ludwigshafen Department of Statistics/Stiftung IHF Institut für Herzinfarktforschung

AIM To evaluate the efficacy of self-expanding metal stents(SEMS) for the palliation of malignant gastric outlet obstruction in patients with and without peritoneal carcinomatosis(PC).METHODS We performed a retrospective analysis of 62 patients who underwent SEMS placement for treatment of malignant gastroduodenal obstruction at our hospital over a six-year period. Stents were deployed through the scope under combined fluoroscopic and endoscopic guidance. Technical success was defined as successful stent placement and expansion. Clinical success was defined as an improvement in the obstructive symptoms and discharge from hospital without additional parenteral nutrition. According to carcinomatosis status, patients were assigned into groups with or without evidence of peritoneal *** In most cases, obstruction was caused by pancreatic(47%) or gastric cancer(23%). Technical success was achieved in 96.8%(60/62), clinical success in 79%(49/62) of all patients. Signs of carcinomatosis were identified in 27 patients(43.5%). The diagnosis was confirmed by pathology or previous operation in 7 patients(11.2%) and suspected by CT, MRI or ultrasound in 20 patients(32.2%). Presence of carcinomatosis was associated with a significantly lower clinical success rate compared to patients with no evidence of peritoneal disease(66.7% vs 88.6%, P = 0.036). There was no significant difference in overall survival between patients with or without PC(median 48 d vs 70 d, P = 0.21), but patients showed significantly longer survival after clinical success of SEMS placement compared to those experiencing clinical failure(median 14.5 d vs 75 d, P = 0.0003).CONCLUSION Given the limited therapeutic options and a clinical success rate of at least 66.7%, we believe that SEMS are a reasonable treatment option in patients with malignant gastric outlet obstruction with peritoneal carcinomatosis.

关键词： Gastric outlet obstruction Self-expanding metal stents Peritoneal carcinomatosis Palliation Endoscopy

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Enhanced migration of tissue inhibitor of metalloproteinase overexpressing hepatoma cells is attributed to gelatinases: Relevance to intracellular signaling pathways

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World Journal of Gastroenterology 2005年第8期11卷 1096-1104页

作者： Elke Roeb Anja-Katrin Bosserhoff Sabine Hamacher bettina Jansen Judith Dahmen Sandra Wagner Siegfried Matern Department of Internal Medicine Ⅲ Institute of Pathology

AIM: To study the effect of gelatinases (especially MMP-9) on migration of tissue inhibitor of metalloproteinase (TIMP-1) overexpressing hepatoma cells. METHODS: Wild type HepG2 cells, cells stably transfected with TIMP-1 and TIMP-1 antagonist (MMP-9-H401A, a catalytically inactive matrix metalloproteinase (MMP) which still binds and neutralizes TIMP-1) were incubated in Boyden chambers either with or without Galardin (a synthetic inhibitor of MMP-1, -2, -3, -8, -9) or a specific inhibitor of gelatinases. RESULTS: Compared to wild type HepG2 cells, the cells overexpressing TIMP-1 showed 115% migration (P<0.05) and the cells overexpressing MMP-9-H401A showed 62% migration (P<0.01). Galardin reduced cell migration dose dependently in all cases. The gelatinase inhibitor reduced migration in TIMP-1 overexpressing cells predominantly. Furthermore, we examined intracellular signal transduction pathways of TIMP-1-dependent HepG2 cells. TIMP-1 deactivates cell signaling pathways of MMP-2 and MMP-9 involving p38 mitogen-activated protein kinase. Specific blockade of the ERK pathway suppresses gelatinase expression either in the presence or absence of TIMP-1. CONCLUSION: Overexpressing functional TIMP-1-enhanced migration of HepG2-TIMP-l cells depends on enhanced MMP-activity, especially MMP-9.

关键词： HepG2 MMP-2 MMP-9 p38MAPK Galardin Genistein

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Preprotein Import into Chloroplasts via the Toc and Tic Complexes Is Regulated by Redox Signals in Pisum sativum

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Molecular Plant 2009年第6期2卷 1181-1197页

作者： Anna Stengel J. Philipp Benz Bob B. Buchanan Jurgen Soil bettina Bolter Munich Center for Integrated Protein Science CiPS^M Ludwig-Maximilians-Universitat Munchen Feodor-Lynen-Strasse 25 D-81377 Munich Germany Department of Biology I Botany Ludwig-Maximilians-Universitat Munchen Groβhaderner Strasse 2-4 D-82152 Planegg-Martinsried Germany Department of Plant and Microbial Biology University of California 411 Koshland Hall Berkeley CA 94720 USA

The import of nuclear-encoded preproteins is necessary to maintain chloroplast function. The recognition and transfer of most precursor proteins across the chloroplast envelopes are facilitated by two membrane-inserted protein complexes, the translocons of the chloroplast outer and inner envelope （Toc and Tic complexes, respectively）. Several signals have been invoked to regulate the import of preproteins. In our study, we were interested in redox-based import regulation mediated by two signals： regulation based on thiols and on the metabolic NADP＋/NADPH ratio. We sought to identify the proteins participating in the regulation of these transport pathways and to characterize the preprotein subgroups whose import is redox-dependent. Our results provide evidence that the formation and reduction of disulfide bridges in the Toc receptors and Toc translocation channel have a strong influence on import yield of all tested preproteins that depend on the Toc complex for translocation. Furthermore, the metabolic NADP＋/NADPH ratio influences not only the composition of the Tic complex, but also the import efficiency of most, but not all, preproteins tested. Thus, several Tic subcomplexes appear to participate in the translocation of different preprotein subgroups, and the redox-active compo- nents of these complexes likely play a role in regulating transport.

关键词： Metabolic regulation molecular transport transport processes/kinetics chloroplast biology protein targeting.

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Plants as concept generators for biomimetic light-weight structures with variable stiffness and self-repair mechanisms

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Journal of Bionic Engineering 2004年第4期1卷 199-205页

作者： Thomas Speck Tom Masselter bettina Prim Olga Speck Rolf Luchsinger Siegfried Fink KompetenznetzBiomimetik der Universit tFreiburg Sch nzlestr.1 D179104 Freiburg Germany Botanischer Garten der Universit t Freiburg Sch nzlestr.1D179104 FreiburgGermany Prospective conceptsag Flughofstr.41 CH18152 Glattbrugg Switzerland Institut fur Forsfbotanik und Baumphysiologie der UniversittFreiburg Sch nzlest:1D179104 FreiburgGemmany

Plants possess many structural and functional properties that have a high potential to serve as concept generators for the production of biomimetic technical materials and structures. We present data on two features of plants (variable stiffness due to pressure changes in cellular structures and rapid self-repair functions) that may be used as models for biomimetic projects.

关键词： bionics biomimetics self-repair pneumatic structures Tensairity Aristolochia

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Yb-and Er concentration dependence of the upconversion luminescence of highly doped NaYF_(4):Yb,Er/NaYF_(4):Lu core/shell nanocrystals prepared by a water-free synthesis

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Nano Research 2022年第10期15卷 9639-9646页

作者： Christian Würth bettina Grauel Monika Pons Florian Frenzel Philipp Rissiek Kerstin Rücker Markus Haase Ute Resch-Genger Federal Institute for Materials Research and Testing(BAM) Division BiophotonicsRichard-Willstaetter-Str.1112489 BerlinGermany Institut für Chemie Neuer Materialien Fachbereich Biologie/ChemieUniversität OsnabrückBarbarastraße 749076 OsnabrückGermany

High sensitizer and activator concentrations have been increasingly examined to improve the performance of multi-color emissive upconversion(UC)nanocrystals(UCNC)like NaYF_(4):Yb,Er and first strategies were reported to reduce concentration quenching in highly doped *** luminescence(UCL)is,however,controlled not only by dopant concentration,yet by an interplay of different parameters including size,crystal and shell quality,and excitation power density(P).Thus,identifying optimum dopant concentrations requires systematic studies of UCNC designed to minimize additional quenching pathways and quantitative ***,we quantify the dopant concentration dependence of the UCL quantum yield(ΦUC)of solid NaYF_(4):Yb,Er/NaYF_(4):Lu upconversion core/shell nanocrystals of varying Yb3+and Er3+concentrations(Yb3+series:20%‒98%Yb3+;2%Er3+;Er3+series:60%Yb3+;2%‒40%Er3+).To circumvent other luminescence quenching processes,an elaborate synthesis yielding OH-free UCNC with recordΦUC of~9%and~25 nm core particles with a thick surface shell were *** Yb3+concentrations barely reduceΦUC from~9%(20%Yb3+)to~7%(98%Yb3+)for an Er3+concentration of 2%,thereby allowing to strongly increase the particle absorption cross section and UCNC *** an increased Er3+concentration reducesΦUC from~7%(2%Er3+)to 1%(40%)for 60%Yb3+.Nevertheless,at very high P(>1 MW/cm^(2))used for microscopic studies,highly Er3+-doped UCNC display a high brightness because of reduced *** findings underline the importance of synthesis control and will pave the road to many fundamental studies of UC materials.

关键词： highly doped upconversion nanocrystals core/shell nanoparticles upconversion luminescence efficiency NaYF_(4):Yb Er concentration quenching

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Spontaneous elimination of hepatitis C virus infection: A retrospective study on demographic, clinical, and serological correlates

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World Journal of Gastroenterology 2007年第31期13卷 4224-4229页

作者： Perdita Wietzke-Braun Larissa bettina Mnhardt Albert Rosenberger Angela Uy Giuliano Ramadori Sabine Mihm Department of Gastroenterology and Endocrinology Robert-Koch-Str.40 37075 Gttingen Germany Department of Genetic Epidemiology Humboldtallee 32 Gttingen 37073 Germany Department of Microbiology Kreuzbergring 57 Gttingen Georg-August-Universitt Gttingen 37075 Germany

To find correlates to spontaneous clearance of hepatitis C virus （HCV） infection, this study compared individuals with self-limited and chronic infection with regard to clinical, demographic, and serological pa- rameters. METHODS： Sixty-seven anti-HCV positive and repeatedly HCV RNA negative individuals were considered to have resolved HCV infection spontaneously. To determine the viral genotype these patients had been infected with HCV serotyping was performed. For comparison reasons, 62 consecutive patients with chronic hepatitis C were enrolled. Cases and controls were compared stratified for age and sex. RESULTS： Retrospective analysis showed （1） a lower humoral reactivity to HCV in patients with self-limited compared to chronic HCV-infection and （2） that younger age, history of iv drug use, and acute/post-acute hepatitis A or B co-infections, but not viral genotypes, are independent correlates for spontaneous HCV clearance. CONCLUSION： The stronger humoral reactivity to HCV in patients with persistent infections and in those with a history of iv drug use is supposed to be due to continuous or repeated contact（s） to the antigen. Metachronous hepatitis A or hepatitis B infections might favor HCV clearance.

关键词： Hepatitis C virus Hepatitis Self-limitedinfection Anti-HCV antibodies Co-infection HCVserotype

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Ecological characterization of soil-inhabiting and hypolithic soil crusts within the Knersvlakte,South Africa

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Ecological Processes 2013年第1期2卷 85-97页

作者： bettina Weber Dirk CJ Wessels Kirstin Deutschewitz Stephanie Dojani Hans Reichenberger Burkhard Büdel Department of Biology University of KaiserslauternPlant Ecology and SystematicsPO Box 3049Kaiserslautern 67653Germany Department of Multiphase Chemistry Max Planck Institute for ChemistryHahn-Meitner-Weg 1Mainz 55128Germany Department of Biodiversity School of Molecular and Life SciencesUniversity of LimpopoTurfloop CampusPrivate Bag X106Sovenga 0727South Africa URS Deutschland GmbH Europaallee 3-5Kaiserslautern 67657Germany.

Introduction:Within the Knersvlakte,cyanobacteria occur hypolithically underneath translucent quartz stones in areas with quartz pavement and,outside pavement areas,they are soil-inhabiting within the uppermost millimeters of the *** habitats were characterized in terms of biomass and growth patterns of ***-term microclimatic conditions were ***:Biomass of organisms within both habitats was determined by means of chlorophyll analyses.A transect approach was used to determine the frequency of hypolithic growth depending on the size,weight,and embedding depth of the quartz *** were identified by means of microscopic analyses of the *** conditions within both habitats,i.e.,temperature,light intensity,air humidity,and soil moisture,were recorded bi-hourly from September 23,2004 through September 7,***:The biomass of hypolithic and soil-inhabiting crusts was almost identical,88 vs.86 mg Chla/m^(2)and 136 vs.134 mg Chla+b/m^(2).Within the quartz fields,46.8%of the surface area was covered by quartz stones with 69%of translucent quartz stones colonized by hypolithic cyanobacteria and *** quartz stones were significantly thicker,heavier,and more deeply embedded in the soil than uncolonized *** the annual mean temperature on top of quartz stones was nearly identical to that underneath thin and thick quartz stones,daily temperature amplitudes were largest on the stone surface(up to 48.1K),compared to the hypolithic habitats(up to 39.4K).Light intensity in the hypolithic habitat was between 15 and 30%of the ambient light intensity during *** condensation in the absence of rain occurred during 50%of the nights on the quartz stone surface,but only during 34%of the nights on the soil surface during winter months within 1 *** moisture beneath quartz layers was greater and less variable than beneath soil-inhabiting ***:In spite of the large differences in

关键词： Hypolithic Quartz Temperature Microclimate

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Differential selection in HIV-1 gp120 between subtype B and East Asian variant B'

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Virologica Sinica 2014年第1期29卷 40-47页

作者： Stefan Dang Yan Wang bettina Budeus Jens Verheyen Rongge Yang Daniel Hoffmann Research Group Bioinformatics Center of Medical Biotechnology and Faculty of BiologyUniversity of Duisburg-Essen AIDS and HIV Research Group State Key Laboratory of VirologyWuhan Institute of VirologyChineseAcademy of Sciences Institute of Virology University of Duisburg-Essen

HIV-1 evolves strongly and undergoes geographic differentiation as it spreads in diverse host populations around the *** instance,distinct genomic backgrounds can be observed between the pandemic subtype B,prevalent in Europe and North-America,and its offspring clade B＇ in East *** we ask whether this differentiation affects the selection pressure experienced by the *** answer this question we evaluate selection pressure on the HIV-1 envelope protein gp120 at the level of individual codons using a simple and fast estimation method based on the ratio ka/ks of amino acid changes to synonymous *** validate the approach we compare results to those from a state-of-the-art mixed-effect *** agreement is acceptable,but the analysis also demonstrates some limitations of the simpler ***,we find similar distributions of codons under stabilizing and directional selection pressure in gp120 for subtypes B and B＇ with more directional selection pressure in variable loops and more stabilizing selection in the constant *** on codons with increased ka/ks values in B＇,we show that these codons are scattered over the whole of gp120,with remarkable clusters of higher density in regions flanking the variable *** identify a significant statistical association of glycosylation sites and codons with increased ka/ks values.

关键词： human immunodeficiency virus 1 selection pressure genomic background

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