检索结果-南通市图书馆

维普期刊数据库

Fecal cytolysin does not predict disease severity in acutely decompensated cirrhosis and acute-on-chronic liver failure

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2023年第5期22卷 474-481页

作者： Phillipp Hartmann Sonja Lang Robert Schierwagen Sabine klein Michael Praktiknjo Jonel Trebicka Bernd Schnabl Department of Pediatrics University of California San DiegoLa JollaCAUSA Division of Gastroenterology Hepatology&NutritionRady Children’s Hospital San DiegoSan DiegoCAUSA Department of Medicine University of California San DiegoLa JollaCAUSA Department of Gastroenterology and Hepatology Faculty of MedicineUniversity of CologneUniversity Hospital CologneCologneGermany Department of Internal Medicine B University of MünsterMünsterGermany European Foundation for the Study of Chronic Liver Failure BarcelonaSpain Department of Medicine VA San Diego Healthcare SystemSan DiegoCAUSA

Background:Cirrhosis with acute decompensation(AD)and acute-on-chronic liver failure(ACLF)are characterized by high morbidity and ***,a toxin from Enterococcus faecalis(***),is associated with mortality in alcohol-associated hepatitis(AH).It is unclear whether cytolysin also contributes to disease severity in AD and ***:We studied the role of fecal cytolysin in 78 cirrhotic patients with AD/*** DNA from fecal samples was extracted and real-time quantitative polymerase chain reaction(PCR)was *** association between fecal cytolysin and liver disease severity in cirrhosis with AD or ACLF was ***:Fecal cytolysin and *** abundance did not predict chronic liver failure(CLIF-C)AD and ACLF *** of fecal cytolysin was not associated with other liver disease markers,including Fibrosis-4(FIB-4)index,‘Age,serum Bilirubin,INR,and serum Creatinine(ABIC)’score,Child-Pugh score,model for end-stage liver disease(MELD)nor MELD-Na scores in AD or ACLF ***:Fecal cytolysin does not predict disease severity in AD and ACLF *** predictive value of fecal cytolysin positivity for mortality appears to be restricted to AH.

关键词： Liver disease Acute decompensation Acute-on-chronic liver failure Microbiome Model for end-stage liver disease

维普期刊数据库

Maize Development: Cell Wall Changes in Leaves and Sheaths

在线全文

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2017年第6期8卷 1248-1263页

作者： Ronald D. Hatfield Jane M. marita USDA-Agricultural Research Service U.S. Dairy Forage Research Center Madison Wisconsin USA

Developmental changes occur in maize (Zea mays L.) as it transitions from juvenile stages to the mature plant. Changes also occur as newly formed cells mature into adult cells. Maize leaf blades including the midribs and sheaths undergo cell wall changes as cells transition to fully mature cell types. As is common in grasses during cell wall maturation, the lignin in the plant tissue is acylated with p-coumarates (pCA). This work characterizes cell walls in maize that make up leaf blade, leaf midrib, and sheath tissues corresponding to tissue development. Maize plants grown in the greenhouse were harvested;leaf, leaf midrib, and sheath tissues from nodes 9 through 14 tissues were analyzed for cell wall composition. Cell wall carbohydrates varied with the type of maize tissue, but there was little change within a tissue type among the different nodes. Lignin concentrations were lowest in the leaf blade (70 - 88 g·kg-1 CW) followed by the sheath (123 - 140 g·kg-1 CW) and highest in the midrib (140 - 168 g·kg-1 CW). Incorporation of pCA into cell walls paralleled the lignification. Ferulates (FA) remained relatively constant as a proportion of the cell wall (3.1 - 6.4 g·kg-1 CW) across nodes and across all tissue types. The range of FA was 3.8 vs 5.7 g·kg-1 CW averaged over all nodes with leaf blades being the lowest. Lignin composition did not change significantly with cell wall maturation within a given tissue type. The aerial portions of maize plants excluding the stem showed little difference in cell wall composition along the different nodes. Higher levels of ferulates were found in the sheath and leaf midrib compared to the leaf blade tissues. Leaf midribs from the upper nodes of the plant contained the highest levels of lignin. Perhaps a reflection of the function to keep leaves extended and in an upward angle to help maximize photosynthetic capacity.

关键词： Maize Cell Walls Lignin Phenolics Structural Carbohydrates

Two-dimensional modeling of fine sediment transport with mixed sediment and consolidation: Application to the Gironde Estuary,France

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2021年第6期36卷 736-746页

作者： Sylvain Orseau Nicolas Huybrechts Pablo Tassi Damien Pham Van Bang Fabrice klein Cerema Direction Technique Eau Mer et Fleuves Sorbonne Universités Université de Technologie de Compiégne CNRSFRE2012 RobervalCentre de Recherche Royallieu Electricité de France R&D Department Laboratoire d'Hydraulique Saint Venant (ENPC-EDF/R&D-CEREMA) 5. Centre Eau Terre et Environnement INRS-ETE 6. Grand Port Maritime de Bordeaux

In order to optimize ship navigation in the macrotidal Gironde Estuary, a recent project funded by the port of Bordeaux aims at better understand and forecast hydrodynamic and fine sediment transport within the estuary. In the framework of this project, a two-dimensional hydro-sedimentary model is built. The model includes hydrodynamic forcings, mixed-sediment transport, and consolidation processes. The harmonic analysis of the astronomical tides reveals a strong distortion of the tidal wave inducing the growth of overtide constituents and the non-significant effect of tide-surge interactions in annual-scale prediction. Depending on hydrological conditions, river discharge can considerably alter the model accuracy due to the migration of the turbidity maximum zone modifying the bottom *** with measurements shows the ability of the model to reproduce suspended-sediment concentrations in the central Estuary. Sensitivity of the model to sediment features has also been discussed in regard of suspended-sediment concentrations and fluid mud deposits. The model will be further coupled with ship squat predictions and a morphodynamic model.

关键词： Sediment transport Numerical modeling Mixed sediment Gironde Estuary Opentelemac

Tetraphenylethylene-BODIPY aggregation-induced emission luminogens for near-infrared polymer light-emitting diodes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第8期61卷 932-939页

作者： Sebnem Baysec Alessandro Minotto Patrick klein Simone Poddi Andrea Zampetti Sybille Allard Franco Cacialli Ullrich Scherf Macromolecular Chemistry and Institute for Polymer Technology Bergische Universitat Wuppertal Wuppertal 42097 Germany Department of Physics and Astronomy and London Centre for Nanotechnology University College London London WCIE 6BT UK

The aggregation-induced emission(AIE) phenomenon provides a new direction for the development of organic light-emitting devices. Here, we present a new class of emitters based on 4,4-difluoro-4-bora-3 a,4 a-diaza-s-indacene(BODIPY), functionalized at different positions with tetraphenylethylene(TPE), which is one of the most famous AIE luminogens. Thanks to this modification, we were able to tune the photoluminescence of the BODIPY moiety from the green to the near-infrared(NIR)spectral range and achieve PL efficiencies of ~50% in the solid state. Remarkably, we observed an enhancement of the AIE and up to ~100% photoluminescence efficiencies by blending the TPE-substituted BODIPY fluorophores with a poly[(9,9-di-noctylfluorene-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,7-diyl)](F8 BT) matrix. By incorporating these blends in organic lightemitting diodes(OLEDs), we obtained electroluminescence peaked in the range 650–700 nm with up to 1.8% external quantum efficiency and ~2 m W/cm2 radiance, a remarkable result for red/NIR emitting and solution-processed OLEDs.

关键词： BODIPY organic light-emitting diode aggregation-induced emission NIR emission photoluminescence electro luminescence

维普期刊数据库

Morphological alterations and redox changes associated with hepatic warm ischemia-reperfusion injury

在线全文

学校读者我要写书评

暂无评论

World Journal of Hepatology 2017年第34期9卷 1261-1269页

作者： Rim Jawad Melroy D'souza Lisa Arodin Selenius marita Wallenberg Lundgren Olof Danielsson Greg Nowak Mikael Bjornstedt Bengt Isaksson Division of Pathology Department of Laboratory Medicine Karolinska Institutet Department of Clinical Science Intervention and Technology (CLINTEC) Division of Surgery Karolinska Institutet Karolinska University Hospital Department of Clinical Science Intervention and Technology (CLINTEC) Division of Transplantation Surgery Karolinska Institutet Karolinska University Hospital

AIM To study the effects of warm ischemia-reperfusion(I/R) injury on hepatic morphology at the ultrastructural level and to analyze the expression of the thioredoxin(TRX)and glutaredoxin(GRX) *** Eleven patients undergoing liver resection were subjected to portal triad clamping(PTC). Liver biopsies were collected at three time points; first prior to PTC(baseline), 20 min after PTC(post-ischemia) and 20 min after reperfusion(post-reperfusion). Electron microscopy and morphometry were used to study and quantify ultrastructural changes, respectively. Additionally, gene expression analysis of TRX and GRX isoforms was performed by quantitative PCR. For further validation of redox protein status, immunogold staining was performed for the isoforms GRX1 and *** Post-ischemia, a significant loss of the liver sinusoidal endothelial cell(LSEC) lining was observed(P = 0.0003) accompanied by a decrease of hepatocyte microvilli in the space of Disse. Hepatocellular morphology was well preserved apart from the appearance of crystalline mitochondrial inclusions in 7 out of 11 patients. Postreperfusion biopsies had similar features as post-ischemia with the exception of signs of a reactivation of the LSECs. No changes in the expression of redox-regulatory genes could be observed at mR NA level of the isoforms of the TRX family but immunoelectron microscopy indicated a redistribution of TRX1 within the *** At the ultrastructural level, the major impact of hepatic warm I/R injury after PTC was borne by the LSECs with detachment and reactivation at ischemia and reperfusion, respectively. Hepatocytes morphology were well preserved. Crystalline inclusions in mitochondria were observed in the hepatocyte after ischemia.

关键词： Hepatic ischemia-reperfusion injury Ischemia reperfusion injury Warm ischemia-reperfusion injury Glutaredoxins Thioredoxins Electron microscopy Oxidative stress Portal triad clamping

Redox-Dependent Regulation of the Stress-Induced Zinc-Finger Protein SAP12 in Arabidopsis thaliana

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2009年第2期2卷 357-367页

作者： Elke Stroeher Xin-Jia Wang Nils Roloff Peter klein Arne Husemann Karl-Josef Dietz Biochemistry and Physiology of Plants Bielefeld University 33501 Bielefeld Germany

The stress-associated protein SAP12 belongs to the stress-associated protein （SAP） family with 14 members in Arabidopsis thaliana. SAP12 contains two AN1 zinc fingers and was identified in diagonal 2D redox SDS-PAGE as a protein undergoing major redox-dependent conformational changes. Its transcript was strongly induced under cold and salt stress in a time-dependent manner similar to SAP10, with high levels after 6 h and decreasing levels after 24 and 48 h. The tran- script regulation resembled those of the stress marker peroxiredoxin PrxllD at 24 and 48 h. Recombinant SAP12 protein showed redox-dependent changes in quaternary structure as visualized by altered electrophoretic mobility in non-reducing SDS polyacrylamide gel electrophoresis. The oxidized oligomer was reduced by high dithiothreitol concentrations, and also by E. coli thioredoxin TrxA with low dithiothreitol （DTF） concentrations or NADPH plus NADPH-dependent thioredoxin reductase. From Western blots, the SAP12 protein amount was estimated to be in the range of 0.5 ngμg^-1 leaf protein. SAP12 protein decreased under salt and cold stress. These data suggest a redox state-linked function of SAP12 in plant cells particularly under cold and salt stress.

关键词： abiotic/environmental stress cold acclimation cell signaling gene expression Arabidopsis A20 and AN1 Zinc finger domains redox regulation stress associated protein thioredoxin.

Tribological behaviour of sintered iron based self-lubricating composites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2017年第3期5卷 285-307页

作者： Jose Daniel Biasoli DE MELLO Cristiano BINDER Gisele HAMMES Roberto BINDER Aloisio Nelmo klein Laboratorio de Materiais(LabMat) Universidade Federal de Santa Catarina Florianópolis 88.040-900 SC BrazilLaboratorio de Tribologia e Materiais Universidade Federal de Uberl(a)ndia Uberl(a)ndia 38.400-902 MG Brazil Laboratorio de Materiais(LabMat) Universidade Federal de Santa Catarina Florianópolis 88.040-900 SC Brazil Whirlpool Embraco Unit Joinville 89.219-900 SC Brazil

This work is a review of previous works,presenting and discussing the most important results obtained by an ongoing research program towards the development of innovative,low-cost,self-lubricating composites with a low friction coefficient and high mechanical strength and wear *** emphasis is given to uniaxial die pressing of solid lubricant particles mixed with matrix powders and to metal injection moulding associated with in situ generation of solid lubricant ***,a microstructural model/processing route (powder injection moulding followed by plasma-assisted debinding and sintering) produced a homogeneous dispersion of in situ generated solid lubricant *** nodules of graphite with diameter smaller than 20 μm were formed,constituting a nanostructured stacking of graphite foils with nanometric *** Raman analysis indicated that the graphite nodules were composed of turbostratic 2D graphite having highly misaligned graphene planes separated by large interlamellae *** interplanar distance between the graphene foils and misalignment of these foils were confirmed by transmission electron microscopy and were,probably,the origin of the outstandingly low dry friction coefficient (0.04).The effect of sintering temperature,precursor content,metallic matrix composition and surface finish is also ***,the influence of a double-pressing/double-sintering (DPDS) technique on the tribological performance of self-lubricating uniaxially die-pressed hBN + graphite-Fe-Si-C-Mo composite is also ***,the tribological behaviour of die-pressed Fe-Si-C matrix composites containing 5,7.5 and 10 wt％ solid lubricants (hBN and graphite) added during the mixing step is analysed in terms of mechanical properties and wear ***,the synergy between solid lubricant particles dispersed in a metallic matrix and fluid lubricants in a cooperative mixed lubrication regime is presented.

关键词： tribological behaviour powder metallurgy iron based self-lubricating composites turbostratic graphite

Tree diversity and nectar composition affect arthropod visitors on extrafloral nectaries in a diversity experiment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2017年第1期10卷 201-212页

作者： Michael Staab Joel Methorst Jan Peters Nico Blüthgen Alexandra-Maria klein Faculty of Environment and Natural Resources Chair of Nature Conservation and Landscape EcologyUniversity of FreiburgTennenbacher Straße 479106 FreiburgGermany Institute of Ecology Leuphana University of LüneburgScharnhorststraße 121335 LüneburgGermany Ecological Network Group Department of BiologyTechnical University DarmstadtSchnittspahnstraße 1064287 DarmstadtGermany

Aims Plants with extrafloral nectaries(EFNs)are common in tropical and subtropical habitats and,despite many other arthropods also forage for EFN,most studies solely focused on the defense mutualisms between EFN plants and *** study aims at a quantitative assessment of the entire arthropod community that visits EFN trees to compare visitor communities between different tree species to disentangle the mechanisms that may drive EFN visitor community *** also test for tree diversity effects on EFN visitors,as it is unknown if local tree species richness relates to the abundance and species richness of arthropods foraging for *** We sampled EFN-visiting arthropods in the experimental tree species richness gradient of the BEF-China Experiment,the currently largest forest diversity experiment in the world,and tested if tree species richness affects EFN visitors and if visitor community composition differs between EFN tree *** a second step,we analyzed the EFN of Ailanthus altissima and Triadica cochinchinensis,the two EFN tree species with highest visitor abundance,for sugars and amino acids(AA)to test if tree species-specific differences in nectar chemistry translate to differing visitor ***,we conducted a choice experiment using different artificial nectar solutions to test if nectar quality affects foraging decisions of ants,the most frequent EFN visitors in our study *** Findings EFN trees in young successional forests in subtropical South-East China are visited by a diverse assemblage of arthropods including ants,beetles,flies,and *** ants accounted for about 75%of all individuals,non-ant visitors were by far more species *** abundance and species richness declined with increasing tree species richness,suggesting a resource dilution effect,because plots with more tree species had proportionally less EFN tree individuals and thus lower nectar *** altissima and ***

关键词： amino acids BEF-China choice experiment formicidae HPLC chemical analysis

Impact of Expressing p-Coumaryl Transferase in Medicago sativa L. on Cell Wall Chemistry and Digestibility

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2016年第17期7卷 2553-2569页

作者： Jane M. marita Dave Rancour Ronald Hatfield Paul Weimer CWBURU of U.S. Dairy Forage Research Center Madison WI USA

The addition of p-coumaric acid (pCA) to lignin molecules is frequently found in members of the grass family. The role of this addition is not clearly understood, but is thought to potentially aid in the formation of syringyl-type lignin. This is because the incorporation is as a conjugate of pCA ester linked to sinapyl alcohol, a major component of lignin. The forage legume alfalfa (Medicago sativa L.) does not contain appreciable levels of pCA in its more heavily lignified stem tissues. The maize p-coumaryltransferase (pCAT) gene was used to transform alfalfa to determine its impact upon lignin composition and its potential to alter cell wall digestibility. A constitutive expression vector using the cassava vein mosaic virus (CsVMV) promoter was used to drive expression of maize pCAT in alfalfa. Expression of the pCAT transgene was detected in both leaves and stems. Though there was a range of pCAconcentration in transformed alfalfa stems (0.2 - 1.79 micrograms (μg)), this was a clear increase over bound pCA in control stems (0.15 - 0.2 mean = 0.17 micrograms (μg)). This did not lead to consistent responses concerning total lignin in the stem tissues. Leaf tissue, on the other hand, already has a relatively high level of pCA (0.85 - 1.2, mean = 0.99 micrograms (μg)) and those expressing pCAT gene showed on average a small increase, but there is a wide range of values among the transformants (0.38 - 1.55, mean = 1.06 micrograms (μg)). Lignin in leaves did not appear to be significantly impacted. However, incorporation of pCA into the wall appears to cause a shift in lignin composition. Testing the pCAT expressing stem cell walls for digestibility using a rumen in vitro system showed there was no change in the digestibility of the stem compared to empty vectors and control alfalfa stems. Although expression of pCAT gene in alfalfa changes the amount of wall bound pCA, it does not appear to change lignin levels or impact digestibility.

关键词： Alfalfa p-Coumarate Cell Wall Lignin Digestibility