bluuebunny/crossref_metadata_2025_split huggingface dataset:
Far‐reaching effects of a seal scarer on harbour porpoises, Phocoena phocoena
Authors: Brandt Miriam J. , Höschle Caroline , Diederichs Ansgar , Betke Klaus , Matuschek Rainer , Witte Sophia , Nehls Georg 
Published: December 2012

ABSTRACTAlthough seal scarers are widely used both to reduce economic losses at fish farms caused by seal predation and to reduce risks posed to marine mammals by offshore pile driving activities, the spatial extent of their deterrent effect on harbour porpoises is still largely unclear. However, this information is crucial to understanding the effects these devices have on the marine environment and to judge their potential as a mitigation measure.A study was conducted in the German North Sea, using passive acoustic monitoring and to some extent simultaneous aerial surveying to specifically study the spatial extent of the deterrence effects of a seal scarer on harbour porpoises. In order to link porpoise detections at various distances to actual sound levels, sound measurements of the seal scarer signal were carried out at several distances from the source.C‐POD recordings revealed a significant deterrence effect on harbour porpoises up to 7.5 km away (at about 113 dB re 1 μParms), much further than previously reported. During seal scarer operation the number of porpoise detections within 750 m of the C‐PODs decreased by between 52 and 95% of the value before the seal scarer was activated.An aerial survey revealed a significant decrease in porpoise density from 2.4 porpoises km‐2before to 0.3 porpoises km‐2during seal scarer operation within the 990 km2study area, showing that the decrease in porpoise detections by passive acoustic monitoring was probably indeed the result of a decrease in porpoise abundance.These results may raise serious concerns about unwanted disturbance effects on harbour porpoises in the context of seal scarer use at fish farms and also highlight the need for caution when applied as a mitigation measure during offshore construction.Copyright © 2012 John Wiley & Sons, Ltd.
Citrullinated calreticulin potentiates rheumatoid arthritis shared epitope signaling
Authors: Ling Song , Cline Erika N. , Haug Timothy S. , Fox David A. , Holoshitz Joseph 
Published: December 2012

AbstractObjectiveCitrullinated proteins are immunogenic in rheumatoid arthritis (RA), particularly in patients who carry shared epitope (SE)–coding HLA–DRB1 alleles. The mechanism underlying this association is unknown. We have previously identified the SE as a ligand that interacts with cell surface calreticulin (CRT) and activates immune dysregulation. This study was undertaken to determine the effect of CRT citrullination on SE signaling.MethodsCRT–SE binding affinity was measured by surface plasmon resonance. The role of individual CRT arginine residues was determined by site‐directed mutagenesis, and nitric oxide levels were measured using a fluorochrome‐based assay. CRT citrullination in synovial tissue samples and cell cultures was determined by 2‐dimensional gel electrophoresis, immunoblotting, and mass spectrometry techniques.ResultsSynovial tissue and fibroblast‐like synoviocytes from RA patients were found to express a higher abundance of citrullinated CRT than samples from osteoarthritis patients. Citrullinated CRT showed more robust interaction with the SE ligand, and transduced SE signaling at a 10,000‐fold higher potency, compared to noncitrullinated CRT. Site‐directed mutation analysis identified Arg205, which is spatially adjacent to the SE binding site in the CRT P‐domain, as a dominant inhibitor of SE–CRT interaction and signaling, while a more remote arginine residue, Arg261, was found to enhance these SE functions.ConclusionOur findings indicate that citrullinated CRT is overabundant in the RA synovium and potentiates SE‐activated signaling in vitro. These findings could introduce a new mechanistic model of gene–environment interaction in RA.
Syndecan 4 supports bone fracture repair, but not fetal skeletal development, in mice
Authors: Bertrand Jessica , Stange Richard , Hidding Heriburg , Echtermeyer Frank , Nalesso Giovanna , Godmann Lars , Timmen Melanie , Bruckner Peter , Dell'Accio Francesco , Raschke Michael J. , Pap Thomas , Dreier Rita 
Published: December 2012

AbstractObjectiveSyndecan 4, a heparan sulfate proteoglycan, has been associated with osteoarthritis. The present study was undertaken to analyze the functional role of syndecan 4 in endochondral ossification of mouse embryos and in adult fracture repair, which, like osteoarthritis, involves an inflammatory component.MethodsSdc4 promoter activity was analyzed in Sdc4−/−lacZ‐knockin mice, using β‐galactosidase staining. Endochondral ossification in embryos from embryonic day 16.5 was assessed by histologic and immunohistologic staining. Bone fracture repair was analyzed in femora of adult mice on days 7 and 14 postfracture. To evaluate Sdc2 and Sdc4 gene expression with and without tumor necrosis factor α (TNFα) and Wnt‐3a stimulation, quantitative real‐time polymerase chain reaction was performed.ResultsIn Sdc4−/−lacZ‐knockin animals, syndecan 4 promoter activity was detectable at all stages of chondrocyte differentiation, and Sdc4 deficiency inhibited chondrocyte proliferation. Aggrecan turnover in the uncalcified cartilage of the epiphysis was decreased transiently in vivo, but this did not lead to a growth phenotype at birth. In contrast, among adult mice, fracture healing was markedly delayed in Sdc4−/−animals and was accompanied by increased callus formation. Blocking of inflammation via anti‐TNFα treatment during fracture healing reduced these changes in Sdc4−/−mice to levels observed in wild‐type controls. We analyzed the differences between the mild embryonic and the severe adult phenotype, and found a compensatory up‐regulation of syndecan 2 in the developing cartilage of Sdc4−/−mice that was absent in adult tissue. Stimulation of chondrocytes with Wnt‐3a in vitro led to increased expression of syndecan 2, while stimulation with TNFα resulted in up‐regulation of syndecan 4 but decreased expression of syndecan 2. TNFα stimulation reduced syndecan 2 expression and increased syndecan 4 expression even in the presence of Wnt‐3a, suggesting that inflammation has a strong effect on the regulation of syndecan expression.ConclusionOur results demonstrate that syndecan 4 is functionally involved in endochondral ossification and that its loss impairs fracture healing, due to inhibition of compensatory mechanisms under inflammatory conditions.
CD22 ligation inhibits downstream B cell receptor signaling and Ca2+ flux upon activation
Authors: Sieger N. , Fleischer S. J. , Mei H. E. , Reiter K. , Shock A. , Burmester G. R. , Daridon C. , Dörner T. 
Published: December 2012

AbstractObjectiveCD22 is a surface molecule exclusively expressed on B cells that regulates adhesion and B cell receptor (BCR) signaling as an inhibitory coreceptor of the BCR. Central downstream signaling molecules that are activated upon BCR engagement include spleen tyrosine kinase (Syk) and, subsequently, phospholipase Cγ2 (PLCγ2), which results in calcium (Ca2+) mobilization. The humanized anti‐CD22 monoclonal antibody epratuzumab is currently being tested in clinical trials. This study was undertaken to determine the potential mechanism by which this drug regulates B cell activation.MethodsPurified B cells were preincubated with epratuzumab, and the colocalization of CD22 and CD79α, without BCR engagement, was assessed by confocal microscopy. The phosphorylation of Syk (Y348, Y352) and PLCγ2 (Y759) as well as the Ca2+ flux in the cells were analyzed by flow cytometry upon stimulation of the BCR and/or Toll‐like receptor 9 (TLR‐9). The influence of CD22 ligation on BCR signaling was assessed by pretreating the cells with epratuzumab or F(ab′)2 fragment of epratuzumab, in comparison with control cells (medium alone or isotype‐matched IgG1).ResultsEpratuzumab induced colocalization of CD22 and components of the BCR independent of BCR engagement, and also reduced intracellular Ca2+ mobilization and diminished the phosphorylation of Syk and PLCγ2 after BCR stimulation in vitro. Inhibition of kinase phosphorylation was demonstrated in both CD27− and CD27+ B cells, and this appeared to be independent of Fc receptor signaling. Preactivation of the cells via the stimulation of TLR‐9 did not circumvent the inhibitory effect of epratuzumab on BCR signaling.ConclusionThese findings are consistent with the concept of targeting CD22 to raise the threshold of BCR activation, which could offer therapeutic benefit in patients with autoimmune diseases.
Multifunctional Uniform Core–Shell Fe3O4@mSiO2 Mesoporous Nanoparticles for Bimodal Imaging and Photothermal Therapy
Authors: Li Jingguo , Jiang Hao , Yu Zhiqiang , Xia Hongyan , Zou Gang , Zhang Qijin , Yu Yue 
Published: December 2012

AbstractMultimodal imaging and simultaneous therapy is highly desirable because it can provide complementary information from each imaging modality for accurate diagnosis and, at the same time, afford an imaging‐guided focused tumor therapy. In this study, indocyanine green (ICG), a near‐infrared (NIR) imaging agent and perfect NIR light absorber for laser‐mediated photothermal therapy, was successfully incorporated into superparamagnetic Fe3O4@mSiO2 core–shell nanoparticles to combine the merit of NIR/magnetic resonance (MR) bimodal imaging properties with NIR photothermal therapy. The resultant nanoparticles were homogenously coated with poly(allylamine hydrochloride) (PAH) to make the surface of the composite nanoparticles positively charged, which would enhance cellular uptake driven by electrostatic interactions between the positive surface of the nanoparticles and the negative surface of the cancer cell. A high biocompatibility of the achieved nanoparticles was demonstrated by using a cell cytotoxicity assay. Moreover, confocal laser scanning microscopy (CLSM) observations indicated excellent NIR fluorescent imaging properties of the ICG‐loaded nanoparticles. The relatively high r2 value (171.6 mM−1 s−1) of the nanoparticles implies its excellent capability as a contrast agent for MRI. More importantly, the ICG‐loaded nanoparticles showed perfect NIR photothermal therapy properties, thus indicating their potential for simultaneous cancer diagnosis as highly effective NIR/MR bimodal imaging probes and for NIR photothermal therapy of cancerous cells.
Effect of Ganglioside GM3 Synthase Gene Knockout on the Glycoprotein N‐Glycan Profile of Mouse Embryonic Fibroblast
Authors: Nagahori Noriko , Yamashita Tadashi , Amano Maho , Nishimura Shin‐Ichiro 
Published: December 2012

AbstractThe structural and clinical significance of cellular glycoproteins and glycosphingolipids (GSLs) are often separately discussed. Considering the biosynthetic pathway of glycoconjugates, glycans of cell‐surface glycoproteins and GSLs might partially share functions in maintaining cellular homeostatis. The purpose of this study is to establish a general and comprehensive glycomics protocol for cellular GSLs and N‐glycans of glycoproteins. To test the feasibility of a glycoblotting‐based protocol, whole glycans released both from GSLs and glycoproteins were profiled concurrently by using GM3 synthase‐deficient mouse embryonic fibroblast GM3(−/−). GM3(−/−) cells did not synthesize GM3 or any downstream product of GM3 synthase. Instead, expression levels of o‐series gangliosides involving GM1‐b and GD1‐α increased dramatically, whereas a‐/b‐series gangliosides were predominantly detected in wild‐type (WT) cells. We also discovered that glycoprotein N‐glycan profiles of GM3(−/−) cells are significantly altered as compared to WT cells, although GM3 synthase is responsible only for GSLs synthesis and is not associated with glycoprotein N‐glycan biosynthesis. The present approach allows for high‐throughput profiling of cellular glycomes enriched by different classes of glycoconjugates, and our results demonstrated that gene knockout of the enzymes responsible for GSL biosynthesis significantly influences the N‐glycans of glycoproteins.
Heterogeneously Catalysed Mild Hydrogenolytic Depolymerisation of Lignin Under Microwave Irradiation with Hydrogen‐Donating Solvents
Authors: Toledano Ana , Serrano Luis , Labidi Jalel , Pineda Antonio , Balu Alina Mariana , Luque Rafael 
Published: December 2012

AbstractA series of hydrogen‐donating solvents have been investigated in lignin depolymerisation practices by using a mild, microwave‐assisted, hydrogen‐free, hydrogenolytic approach promoted by the use of in situ hydrogen generating reagents with Ni 10 % Al‐SBA‐15 as a heterogeneous catalyst. Selected solvents were tetralin, isopropanol, glycerol and formic acid. Final identified products, namely bio‐oil, biochar and residual lignin were characterised by using GC–MS, matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry and high‐performance size‐exclusion chromatography to evaluate the extension of the hydrogenolytic process. Interestingly, the obtained phenolic monomeric products were found to be remarkably affected by the type of hydrogen‐donating solvent, with the best results obtained with formic acid, a potentially renewable derived solvent, which unexpectedly provided no biochar as compared to a maximum of 38 % obtained for tetralin. The reported protocol constitutes another step towards the development of fully sustainable and “green” methodologies of low environmental impact for lignin depolymerisation.
Performance of a New Geometry of Deoiling Hydrocyclones: Experiments and Numerical Simulations
Authors: Nascimento M. R. M. , Bicalho I. C. , Mognon J. L. , Ataíde C. H. , Duarte C. R. 
Published: December 2012

AbstractA new geometry of liquid‐liquid hydrocyclones is proposed seeking to perform the separation of oil emulsified in water. The hydrocyclone performance was investigated by means of a factorial experimental design (23) leading to a total of ten experiments. The results enabled the determination of empirical mathematical models that describe capacity, total separation efficiency, and flow ratio as a function of oil concentration in the feed inlet, operating pressure drop, and presence or absence of a vortex finder in the geometry. Numerical simulations were also carried out to further understand the flow field characteristics in the studied hydrocyclone.
3D Modeling and Simulation of Mass Transfer in Vapor Transport through Porous Membranes
Authors: Shirazian S. , Ashrafizadeh S. N. 
Published: December 2012

AbstractA 3D mathematical model is developed to predict the transport of water vapor through porous membranes. The model is based on solving the continuity, momentum as well as energy equations for water in the membrane contactor. The model's equations are numerically solved using the finite element method to obtain the concentration and temperature distributions of water in the membrane contactor. The model findings were in good agreement with experimental data. The proposed 3D model proved to be appropriate for predicting the performance of a membrane evaporator. Simulations were carried out in order to study the influence of different operating parameters and membrane structure on the membrane evaporation effectiveness. The results of simulation indicate that the gas velocity is a favorable parameter in the membrane evaporation process due to its tendency to keep the process far from the thermodynamic equilibrium.
Multiphase reacting flow studies of bubble column ozonation reactor for water remediation
Authors: Perdigoto M. , Larachi F. , Lopes R. 
Published: December 2012

AbstractA multiphase Volume‐of‐fluid (VOF) model was developed to gain further insights into the reactive flow parameters and electrical capacitance tomography (ECT) measurements on the remediation of hazardous organic pollutants. Low ozone bubble frequencies were obtained for high surface tension fluids, and the liquid viscosity affected the ozone bubbling frequency. The VOF model indicated that the increase of inlet gas velocity enriched the ozone bubble detachment and concomitantly generated larger ozone bubbles, decreasing the detoxification rates. VOF mappings and ECT visualizations of gas‐liquid unveiled preferential routes and highlighted the attenuation of the axisymmetric behavior of the ozonation bubble column under high‐interaction regimes.
Effects and New Applications of Pulsed Flow
Authors: Walzel P. 
Published: December 2012

AbstractPulsed flow has been widely applied in the past for special applications as in jigging or sorting devices, extraction columns, and fluidized‐bed dryers. Recent developments and detailed examinations demonstrate several effects which can be achieved in pulsed operation modes. Here, low‐frequency oscillations are considered, providing a more or less uniform phase state along the flow. Secondary flow is induced at obstacles and can be widely controlled by pulsation parameters keeping the backmixing effect low, despite of high transversal mass or heat exchange intensification. At walls, lift forces on particles within the thin boundary layers are beneficial for keeping particles from building deposits on surfaces or on permeable membranes. Broken symmetry devices generate a directed flow even when operated by a harmonically pulsed fluid. At oscillating interfaces, a distinct secondary flow is observed, well‐suited to intensify mass transfer.
Enzyme‐Responsive Silica Mesoporous Supports Capped with Azopyridinium Salts for Controlled Delivery Applications
Authors: Mas Núria , Agostini Alessandro , Mondragón Laura , Bernardos Andrea , Sancenón Félix , Marcos M. Dolores , Martínez‐Máñez Ramón , Costero Ana M. , Gil Salvador , Merino‐Sanjuán Matilde , Amorós Pedro , Orzáez Mar , Pérez‐Payá Enrique 
Published: December 2012

AbstractThe preparation of a new capped silica mesoporous material, Rh‐Azo‐S, for on‐command delivery applications in the presence of target enzymes is described. The material consists of nanometric mesoporous MCM‐41‐like supports loaded with Rhodamine B and capped with an azopyridine derivative. The material was designed to show “zero delivery” and to display a cargo release in the presence of reductases and esterases, which are usually present in the colon, mainly due to intestinal microflora. The opening and cargo release of Rh‐Azo‐S in vitro studies were assessed and seen to occur in the presence of these enzymes, whereas no delivery was noted in the presence of pepsine. Moreover, Rh‐Azo‐S nanoparticles were used to study controlled Rhodamine B dye delivery in intracellular media. HeLa cells were employed for testing the “non”‐toxicity of nanoparticles. Moreover, delivery of the dye in these cells, through internalization and enzyme‐mediated gate opening, was confirmed by confocal microscopy. Furthermore, the nanoparticles capped with the Azo group and loaded with a cytotoxic camptothecin (CPT) were also prepared (solid CPT‐Azo‐S) and used as delivery nanodevices in HeLa cells. When this solid was employed, the cell viability decreased significantly due to internalization of the nanoparticles and delivery of the cytotoxic agent.
Mechanism and Cellular Kinetic Studies of the Enhancement of Antioxidant Activity by Using Surface‐Functionalized Gold Nanoparticles
Authors: Du Libo , Suo Siqingaowa , Wang Guangqing , Jia Hongying , Liu Ke Jian , Zhao Baolu , Liu Yang 
Published: December 2012

AbstractThe enhanced antioxidant activity of surface‐functionalized gold nanoparticles (AuNPs) synthesized by self‐assembly has attracted great attention, but little is known about the mechanism behind the enhanced activity. To address this challenge, the antioxidant activity of Au@PEG3SA (i.e., surface‐functionalization of spherical AuNPs with the antioxidant salvianic acid A) was used as an example to illustrate the mechanism of the enhanced activity. Evaluation of the antioxidant activity was performed in a radical‐scavenging reaction between Au@PEG3SA and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical. As expected, the rate constant for the reaction of Au@PEG3SA with DPPH was about nine times greater than that for the salvianic acid A monomer. A comparative analysis of the spectral characteristics of Au@PEG3SA and the salvianic acid A monomer further imply that the enhancement of the antioxidative reaction kinetics may be ascribed to the variation in the transition state for the DPPH‐radical scavenging reaction through π–π stacking interactions between and among adjacent groups on the surface of Au@PEG3SA. On the other hand, the kinetic enhancement of Au@PEG3SA on reactive‐oxygen‐species (ROS) scavenging can be observed in living cells and in vivo, which possibly provides new insight for the bioapplication of self‐assembly of surface‐functionalized AuNPs.
Ligand‐Free Synthesis of 1,4‐Disubstituted‐1,3‐diynes by Iron/Copper Cocatalyzed Homocoupling of Terminal Alkynes
Authors: Wang Peipei , Liu Xiaoyan , Zhang Songlin 
Published: December 2012

AbstractA simple and efficient protocol for Fe/Cu cocatalyzed oxidative homocoupling reaction of terminal alkynes to symmetrical 1,4‐disubstituted‐1,3‐diynes was presented. The results showed that both CuBr and FeCl3 played crucial roles in the reaction. It is noteworthy that this protocol employs mild, efficient, aerobic and ligand free conditions. The alkynes, including aromatic, heteroaromatic and aliphatic alkynes, were transformed into the corresponding 1,3‐diynes in good to excellent yields.
Thermal Drying and Alkaline Treatment of Biosolids: Effects on Nitrogen Mineralization
Authors: Silva‐Leal Jorge , Torres‐Lozada Patricia , Cardoza Yasmin J. 
Published: December 2012

AbstractBiosolids from the Cañeveralejo WWTP were dehydrated by filter press and then applied two processes to reduce pathogens (PRP): thermally dried biosolid (TDB) and alkalinized biosolid (AB). Untreated, dehydrated biosolid (DB) was used as a control. We evaluated the impact of thermal drying and alkaline treatments on nitrogen mineralization in these substrates. Moreover, agronomic rates for biosolid applications to sugarcane were estimated for each of the treatments leading to application rates of 35.8, 36.4, and 54.5 t/ha for DB, TDB, and AB, respectively, to meet the nitrogen requirement (200 kg N/ha) for sugarcane cultivation (Saccharum officinarum). The results showed that the biosolid rates used increased the mineral nitrogen content of soils by an average of 93.8 and 439.8 mg/kg for all biosolids and the PRP (thermal drying and alkaline treatment) in biosolids had significant effects on mineralization rate, showing better results for the TDBs.
Fins improve the swimming performance of fish sperm: A hydrodynamic analysis of the Siberian sturgeon Acipenser baerii
Authors: Gillies Eric A. , Bondarenko Volodymyr , Cosson Jacky , Pacey Allan A. 
Published: December 2012

AbstractThe flagella of sturgeon sperm have an ultrastructure comprising paddle‐like fins extending along most of their length. These fins are seen in several other marine and freshwater fish. The sperm of these fish are fast swimmers and are relatively short lived: it is therefore tempting to think of these fins as having evolved for hydrodynamic advantage, but the actual advantage they impart, at such a small length scale and slow speed, is unclear. The phrase “the fins improve hydrodynamic efficiency” is commonly found in biological literature, yet little hydrodynamic analysis has previously been used to support such conjectures. In this paper, we examine various hydrodynamic models of sturgeon sperm and investigate both swimming velocity and energy expenditure. All of the models indicate a modest hydrodynamic advantage of finned sperm, in both straight line swimming speed and a hydrodynamic efficiency measure. We find a hydrodynamic advantage for a flagellum with fins, over one without fins, of the order of 15–20% in straight line propulsive velocity and 10–15% in a hydrodynamic efficiency measure. © 2012 Wiley Periodicals, Inc