bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of plasma duty cycle on silver nanoparticles loading of cotton fabrics for durable antibacterial properties
Authors: Airoudj Aissam , Ploux Lydie , Roucoules Vincent 
Published: August 2014

ABSTRACTA facile method for strongly anchoring silver nanoparticles (AgNPs) onto cotton fabrics was reported. It consists in loading AgNPs onto the cotton fiber preliminary coated with maleic anhydride plasma polymer layer. This results in hydrolyzis and ring opening of anhydride groups followed by electrovalent bonding of silver ions and reduction in NaBH4. X‐ray photoelectron spectroscopy (XPS), infrared spectroscopy, and scanning electron microscope (SEM) were used to analyze changes in the surface chemical composition and morphology of the plasma modified fibers. The presence of AgNPs was confirmed by UV–Visible spectroscopy and atomic force microscopy (AFM) images. Remarkably, varying plasma duty cycle for plasma polymer deposition allowed tailoring the amount of loaded AgNPs. The highest amount of AgNPs was obtained with the lowest duty cycle values. Qualitative tests showed that silver containing plasma modified cotton displays significant antibacterial activity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41279.
The influence of consolidation and artificial weathering on all‐PP composite behavior
Authors: Ferluga Alessio , Caniato Marco , Sbaizero Orfeo 
Published: August 2014

ABSTRACTThe purpose of this work was to evaluate the effect of consolidation parameters on the mechanical properties of all‐polypropylene composites. Consolidation time does not induce any significant influence, whereas processing temperature and in particular coextruded tape characteristics deeply affect laminate performance. The DSC analysis demonstrated that the proximity of copolymer and homopolymer melting points results in a reduction in the operating window. This suggests the implementation of a more effective temperature control during thermoforming to avoid reinforcement relaxation and localized melting. Artificial weathering was conducted under noon summer light condition to assess the effect of ultraviolet exposure on laminates. After 100 and 250 h, sample performance drops significantly, with overall strength and elongation reduction up to 70 and 88%, respectively. Low molecular weight by‐products were identified using Raman spectroscopy on specimens surface, confirming the mechanical property decrement due to photo‐oxidation process. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41283.
Preparation and characterization of Fe‐Tetranitro phthalocyanine/polyurethane blends
Authors: Ti Yang , Chen Dajun 
Published: August 2014

ABSTRACTIn this article, Fe‐Tetranitro phthalocyanine (Fe‐TNPc)/polyurethane (PU) blends were prepared by solution blending. The mechanical properties of the samples were studied by tensile tests. The results showed that the tensile strength and the elongation at break of the samples increased with increasing Fe‐TNPc content. The improved mechanical properties for the samples containing Fe‐TNPc was attributed to the increased microphase separation degree of PU, which was further investigated by dynamic mechanical analysis (DMA) and Fourier transform infrared analysis. The lower Tg of the soft segments and the higher Tg of the hard segments for the samples containing Fe‐TNPc indicated an increase of microphase separation degree of PU. The increased hydrogen bonded carbonyl groups in the samples with increasing Fe‐TNPc content also proved the conclusion. Quantitative evaluation of the interaction between Fe‐TNPc and PU was also investigated by analyzing the physical crosslinking density of the samples. The results indicated that the physical crosslinking density of the samples increased with increasing Fe‐TNPc content. The antibacterial properties of the samples were investigated. The results showed that the percentage bacterial inactivation toward S. aureus and E. coli of the samples were 98.9% and 90.9%, respectively, when Fe‐TNPc was added to 1%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41284.
Intravital microscopy of localized stem cell delivery using microbubbles and acoustic radiation force
Authors: Kokhuis T.J.A. , Skachkov I. , Naaijkens B.A. , Juffermans L.J.M. , Kamp O. , Kooiman K. , van der Steen A.F.W. , Versluis M. , de Jong N. 
Published: August 2014

ABSTRACTThe use of stem cells for the repair of damaged cardiac tissue after a myocardial infarction holds great promise. However, a common finding in experimental studies is the low number of cells delivered at the area at risk. To improve the delivery, we are currently investigating a novel delivery platform in which stem cells are conjugated with targeted microbubbles, creating echogenic complexes dubbed StemBells. These StemBells vibrate in response to incoming ultrasound waves making them susceptible to acoustic radiation force. The acoustic force can then be employed to propel circulating StemBells from the centerline of the vessel to the wall, facilitating localized stem cell delivery. In this study, we investigate the feasibility of manipulating StemBells acoustically in vivo after injection using a chicken embryo model. Bare stem cells or unsaturated stem cells (<5 bubbles/cell) do not respond to ultrasound application (1 MHz, peak negative acoustical pressure P_ = 200 kPa, 10% duty cycle). However, stem cells which are fully saturated with targeted microbubbles (>30 bubbles/cell) can be propelled toward and arrested at the vessel wall. The mean translational velocities measured are 61 and 177 μm/s for P‐ = 200 and 450 kPa, respectively. This technique therefore offers potential for enhanced and well‐controlled stem cell delivery for improved cardiac repair after a myocardial infarction. Biotechnol. Bioeng. 2015;112: 220–227. © 2014 Wiley Periodicals, Inc.
Aniline Carbamates: A Versatile and Removable Motif for Palladium‐Catalyzed Directed CH Activation
Authors: Uhlig Nick , Li Chao‐Jun 
Published: August 2014

AbstractThe aniline carbamate is introduced as a new removable directing group for CH activation. Its versatility and ability as a directing group are demonstrated by its use in the ortho‐arylation of a wide variety of aniline derivatives under palladium(II) catalysis, with symmetric diaryliodonium salts as aryl donors. The reaction differs from previously reported arylations in its selectivity and its mechanism, as elucidated by kinetic and isotopic experiments. The directing group can also be easily removed under a variety of conditions.
Swiprosin‐1/EFhd2 limits germinal center responses and humoral type 2 immunity
Authors: Brachs Sebastian , Turqueti‐Neves Adriana , Stein Merle , Reimer Dorothea , Brachvogel Bent , Bösl Michael , Winkler Thomas , Voehringer David , Jäck Hans‐Martin , Mielenz Dirk 
Published: August 2014

Activated B cells are selected for in germinal centers by regulation of their apoptosis. The Ca2+‐binding cytoskeletal adaptor protein Swiprosin‐1/EFhd2 (EFhd2) can promote apoptosis in activated B cells. We therefore hypothesized that EFhd2 might limit humoral immunity by repressing both the germinal center reaction and the expected enhancement of immune responses in the absence of EFhd2. Here, we established EFhd2−/− mice on a C57BL/6 background, which revealed normal B‐ and T‐cell development, basal Ab levels, and T‐cell independent type 1, and T‐cell independent type 2 responses. However, T cell‐dependent immunization with sheep red blood cells and infection with the helminth Nippostrongylus brasiliensis (N.b) increased production of antibodies of multiple isotypes, as well as germinal center formation in EFhd2−/− mice. In addition, serum IgE levels and numbers of IgE+ plasma cells were strongly increased in EFhd2−/− mice, both after primary as well as after secondary N.b infection. Finally, mixed bone marrow chimeras unraveled an EFhd2‐dependent B cell‐intrinsic contribution to increased IgE plasma cell numbers in N.b‐infected mice. Hence, we established a role for EFhd2 as a negative regulator of germinal center‐dependent humoral type 2 immunity, with implications for the generation of IgE.
Regulation of IFN‐γ by IL‐13 dictates susceptibility to secondary postinfluenza MRSA pneumonia
Authors: Rynda‐Apple Agnieszka , Harmsen Ann , Erickson Anfin S. , Larson Kyle , Morton Rachelle V. , Richert Laura E. , Harmsen Allen G. 
Published: August 2014

Superinfection in mice at day 7 postinfluenza infection exacerbates bacterial pneumonia at least in part via downstream effects of increased IFN‐γ signaling. Here we show that up to 3 days postinfluenza infection, mice have reduced susceptibility to superinfection with methicillin‐resistant Staphylococcus aureus (MRSA), but that superinfection during that time exacerbated influenza disease. This was due to IL‐13 signaling that was advantageous for resolving MRSA infection via inhibition of IFN‐γ, but was detrimental to the clearance of influenza virus. However, if superinfection did not occur until the near resolution of influenza infection (day 7), IL‐13 signaling was inhibited, at least in part by upregulation of IL‐13 decoy receptor (IL‐13Rα2), which in turn caused increases in IFN‐γ signaling and exacerbation of bacterial infection. Understanding these cytokine sequelae is critical to development of immunotherapies for influenza‐MRSA coinfection since perturbations of these sequelae at the wrong time could increase susceptibility to MRSA and/or influenza.
HINT1 peptide/Hsp70 complex induces NK‐cell‐dependent immunoregulation in a model of autoimmune demyelination
Authors: Galazka Grazyna , Jurewicz Anna , Domowicz Malgorzata , Cannella Barbara , Raine Cedric S. , Selmaj Krzysztof 
Published: August 2014

Heat shock proteins (Hsps) interact with the immune system and have been shown to contribute to immunoregulation. As efficient chaperones, Hsps bind many peptides and these complexes have many yet‐to‐be‐clarified functions. We have shown that Hsp70 is complexed within the mouse CNS with peptide CLAFHDISPQAPTHFLVIPK derived from histidine triad nucleotide‐binding protein‐1 (HINT138–57/Hsp70). Only this complex, in contrast to other peptides complexed with Hsp70, was able to prevent experimental autoimmune encephalomyelitis (EAE) by induction of immunoregulatory mechanisms dependent on NK cells. Pretreatment of proteolipid protein peptide 139–151 (PLP139–151) sensitized SJL/J mice with HINT138–57/Hsp70 prevented the development of EAE, suppressed PLP139–151‐induced T‐cell proliferation, and blocked secretion of IL‐17. HINT138–57/Hsp70 stimulation of NK cells depended on synergistic activation of two NK‐cell receptors, CD94 and NKG2D. NK cells with depleted CD94 or with blocked NKG2D did not inhibit PLP139–151‐induced spleen cell (SC) proliferation. The HINT138–57/Hsp70 complex enhanced surface expression of the NKG2D ligand—H60. Downstream signaling of CD94 and NKG2D converged at the adaptor proteins DAP10 and DAP12, and in response to HINT138–57/Hsp70 stimulation, expression of DAP10 and DAP12 was significantly increased in NK cells. Thus, we have shown that the HINT138–57/Hsp70 complex affects NK‐cell function by enhancing NK‐cell‐dependent immunoregulation in the EAE model of autoimmune demyelination.
Sediment connectivity: a framework for understanding sediment transfer at multiple scales
Authors: Bracken Louise J. , Turnbull Laura , Wainwright John , Bogaart Patrick 
Published: August 2014

AbstractA major challenge for geomorphologists is to scale up small‐magnitude processes to produce landscape form, yet existing approaches have been found to be severely limited. New ways to scale erosion and transfer of sediment are thus needed. This paper evaluates the concept of sediment connectivity as a framework for understanding processes involved in sediment transfer across multiple scales. We propose that the concept of sediment connectivity can be used to explain the connected transfer of sediment from a source to a sink in a catchment, and movement of sediment between different zones within a catchment: over hillslopes, between hillslopes and channels, and within channels. Using fluvial systems as an example we explore four scenarios of sediment connectivity which represent end‐members of behaviour from fully linked to fully unlinked hydrological and sediment connectivity. Sediment‐travel distance – when combined with an entrainment parameter reflecting the frequency–magnitude response of the system – maps onto these end‐members, providing a coherent conceptual model for the upscaling of erosion predictions. This conceptual model could be readily expanded to other process domains to provide a more comprehensive underpinning of landscape‐evolution models. Thus, further research on the controls and dynamics of travel distances under different modes of transport is fundamental. Copyright © 2014 John Wiley & Sons, Ltd.
The effects of hydroxylated multiwalled carbon nanotubes on the toxicity of nickel to Daphnia magna under different pH levels
Authors: Wang Chao , Wei Zhongbo , Feng Mingbao , Wang Liansheng , Wang Zunyao 
Published: August 2014

Abstract

Hydroxylated multiwalled carbon nanotubes (OH-MWCNTs), with large amounts of hydrophilic groups attached on the nanoparticle surface, have caused considerable concern because of their inevitable release into aquatic environments. They may interact with other contaminants such as heavy metals and even influence their toxicity, fate, and transport. In the present study, the stability of OH-MWCNTs suspended in aerated Nanjing tap water (moderately hard) was evaluated using the spectrophotometric method. The toxicity of OH-MWCNTs to Daphnia magna was determined, and nontoxic concentrations were used in acute toxicity, accumulation, and sorption tests. It was found that OH-MWCNTs increased the Ni toxicity in a concentration-dependent manner under different pH levels. Nickel adsorption onto the OH-MWCNTs and the uptake of OH-MWCNTs increased the exposure of D. magna to Ni, which was verified by sorption and accumulation tests conducted under different pH levels. The lower pH level contributed to a higher overall toxicity, which could be interpreted by the increasing amount of Ni adsorption onto OH-MWCNTs with the decreasing pH levels. Environ Toxicol Chem 2014;33:2522–2528. © 2014 SETAC
Size-dependent impacts of silver nanoparticles on the lifespan, fertility, growth, and locomotion of Caenorhabditis elegans
Authors: Contreras Elizabeth Q. , Puppala Hema L. , Escalera Gabriela , Zhong Weiwei , Colvin Vicki L. 
Published: August 2014

Abstract

The increased bioavailability of nanoparticles engineered for good dispersion in water may have biological and environmental impacts. To examine this issue, the authors assessed the biological effects in nematodes as they relate to exposure to silver nanoparticles (AgNPs) of different sizes at low (1 mg/L Ag), medium (10 mg/L Ag), and high concentrations (100 mg/L Ag). Over multiple generations, the authors found that the smallest particle, at 2 nm, had a notable impact on nematode fertility. In contrast, the largest particle, at 10 nm, significantly reduced the lifespan of parent nematodes (P0) by 28.8% and over the span of 3 generations (F1–F3). In addition, a computer vision system automatically measured the adverse effects in body length and motility, which were not size-dependent. Environ Toxicol Chem 2014;33:2716–2723. © 2014 SETAC
Accumulation of mercury and cadmium in rice from paddy soil near a mercury mine
Authors: Li W.C. , Ouyang Y. , Ye Z.H. 
Published: August 2014

Abstract

Paddy soil and rice (Oryza sativa L.) in the Wanshan mining area in Guizhou Province, China, have been contaminated by toxic trace metals such as cadmium (Cd) and mercury (Hg). The present study examined correlations between the types and physicochemical parameters of the soil and the contents of trace metals and the different forms of Hg in rice. The health risks of consuming contaminated rice from the Wanshan mining area were also assessed. Sequential extraction procedures were used to investigate the chemical behavior of Hg in the soil. The results showed that Hg and Cd were the most abundant trace metals in the Wanshan mining area. The toxic methylmercury (MeHg) content was substantial in brown rice, and the total amounts of total Hg (THg), diethylenetriaminepentaacetic acid–Hg, and water-soluble Hg varied in the rhizosphere and non-rhizosphere soils. An antagonistic interaction between Mn in brown rice, straw, and husk and MeHg in brown rice was also shown. An analysis of calculated dietary intake, target hazard quotients, and hazard indexes showed a potential risk of transferring Hg, MeHg, and Cd to humans when rice from the Wanshan mining area is consumed. Therefore, it must be concluded that consuming contaminated rice near the Wanshan mining area is a potential threat to human health. Environ Toxicol Chem 2014;33:2438–2447. © 2014 SETAC
Toward a reduction of mesh imprinting
Authors: Lung T. B. , Roe P. L. 
Published: August 2014

SUMMARYThis paper is the initial investigation into a new Lagrangian cell‐centered hydrodynamic scheme that is motivated by the desire for an algorithm that resists mesh imprinting and has reduced complexity. Key attributes of the new approach include multidimensional construction, the use of flux‐corrected transport (FCT) to achieve second order accuracy, automatic determination of the mesh motion through vertex fluxes, and vorticity control. Toward this end, vorticity preserving Lax–Wendroff (VPLW) type schemes for the two‐dimensional acoustic equations were analyzed and then implemented in a FCT algorithm. Here, mesh imprinting takes the form of anisotropic dispersion relationships. If the stencil for the LW methods is limited to nine points, four free parameters exist. Two parameters were fixed by insisting that no spurious vorticity be created. Dispersion analysis was used to understand how the remaining two parameters could be chosen to increase isotropy. This led to new VPLW schemes that suffer less mesh imprinting than the rotated Richtmyer method. A multidimensional, vorticity preserving FCT implementation was then sought using the most promising VPLW scheme to address the problem of spurious extrema. A well‐behaved first order scheme and a new flux limiter were devised in the process. The flux limiter is unique in that it acts on temporal changes and does not place a priori bounds on the solution. Numerical results have demonstrated that the vorticity preserving FCT scheme has comparable performance to an unsplit MUSCL‐H algorithm at high Courant numbers but with reduced mesh imprinting and superior symmetry preservation. Copyright © 2014 John Wiley & Sons, Ltd.
Immunomodulation of cystic fibrosis epithelial cells via NF‐κB decoy oligonucleotide‐coated polysaccharide nanoparticles
Authors: Wardwell Patricia R. , Bader Rebecca A. 
Published: August 2014

AbstractActivation of the transcription factor nuclear factor‐kappa B (NF‐κB) signaling pathway is associated with enhanced secretion of pro‐inflammatory mediators and is thought to play a critical role in diseases hallmarked by inflammation, including cystic fibrosis (CF). Small nucleic acids that interfere with gene expression have been proposed as promising therapeutics for a number of diseases. However, applications have been limited by low cellular penetration and a lack of stability. Nano‐sized carrier systems have been suggested as a means of improving the effectiveness of nucleic acid‐based treatments. In this study, we successfully coated polysialic acid‐N‐trimethyl chitosan (PSA–TMC) nanoparticles with NF‐κΒ decoy oligonucleotides (ODNs). To demonstrate anti‐inflammatory activity, the decoy ODN‐coated PSA–TMC nanoparticles were administered to an in vitro model of CF generated via interleukin‐1β or P. aeruginosa lipopolysaccharides stimulation of IB3‐1 bronchial epithelial cells. While free ODN and PSA–TMC nanoparticles coated with scrambled ODNs did not have substantial impacts on the inflammatory response, the decoy ODN‐coated PSA–TMC nanoparticles were able to reduce the secretion of interleukin‐6 and interleukin‐8, pro‐inflammatory mediators of CF, by the epithelial cells, particularly at longer time points. In general, the results suggest that NF‐κB decoy ODN‐coated TMC‐PSA nanoparticles may serve as an effective method of altering the pro‐inflammatory environment associated with CF. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1622–1631, 2015.
An investigation of scavenger receptor A mediated leukocyte binding to polyanionic and uncharged polymer hydrogels
Authors: Love Ryan J. , Patenaude Mathew , Dorrington Michael , Bowdish Dawn M. E. , Hoare Todd , Jones Kim S. 
Published: August 2014

AbstractCell adhesion to biomaterials can be mediated in part by mechanisms aside from the traditionally recognized opsinization and integrin binding mechanisms. In this study, we investigated the role of scavenger receptor A (SR‐A) in leukocyte binding to a series of well‐controlled polyanionic and uncharged hydrogels based on a poly(N‐isopropylacrylamide) backbone. The hydrogels were injected in the peritoneal cavity of SR‐A knockout (KO) and wild‐type mice using a minimally invasive procedure and allowed to set in situ. After 24 h, the hydrogels were recovered and analyzed, the peritoneal cavity was lavaged, and cytokine concentrations were assessed by ELISA. The polyanionic hydrogels retrieved from the KO animals were found to be completely devoid of adherent leukocytes, which were present in other materials regardless of the mouse strain in which they were injected. Results from a subsequent in vitro cellular adhesion study with a RAW264.7 cell line failed to yield a similarly definitive role for SR‐A in the cellular binding of a polyanionic hydrogel. Taken together, the results of this study show that SR‐A mediates leukocyte adhesion to a polyanionic hydrogel in the peritoneal cavity, but other adhesion mechanisms contribute to cellular binding in vitro. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1605–1612, 2015.
Strontium exerts dual effects on calcium phosphate cement: Accelerating the degradation and enhancing the osteoconductivity both in vitro and in vivo
Authors: Kuang Guan‐Ming , Yau W. P. , Wu Jun , Yeung Kelvin W. K. , Pan Haobo , Lam W. M. , Lu W. W. , Chiu K. Y. 
Published: August 2014

AbstractCalcium phosphate cements (CPCs) have long been used as osteoconductive bone substitutes in the treatment of bone defects. However, the degradation rate of CPC is typically too slow to match the new bone growth rate. It is known that strontium increases the solubility of hydroxyapatite as well as exerts both anabolic and anticatabolic effects on bone. Therefore, we hypothesized that the incorporation of strontium would accelerate the degradation rate and enhance the osteoconductivity of CPC. In this study, Three groups, CPC (0% Sr‐CPC), 5% Sr‐CPC, and 10% Sr‐CPC, were prepared, with the total molar ratio for Sr/(Sr+Ca) in the cement powder phase being 0, 5, and 10%, respectively. In the immersion test, less residual weight was observed in both 5% Sr‐CPC and 10% Sr‐CPC groups than CPC group. In addition, a higher osteoblastic cell proliferation rate and alkaline phosphatase activity were obtained in the strontium groups. In a rat femur bone defect model comparing CPC with 10% Sr‐CPC, at 2 weeks postoperation, early endochondral ossification was found in the 10% Sr‐CPC group, whereas only fibrous tissue was observed in control group; at 4–16 weeks postoperation, progressive osteoconduction toward the cement was observed in both groups. At 32 weeks, a higher peri‐cement bone area and reduced cement area were noted in the 10% Sr‐CPC group. In conclusion, in the 10% Sr‐CPC group, strontium exerts dual effects on CPC: accelerating degradation rate and enhancing osteoconductivity, as shown here both in vitro and in vivo. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1613–1621, 2015.