bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of renewable poly(amidoamine)/hemicellulose hydrogels for heavy metal adsorption
Authors: Ferrari Elena , Ranucci Elisabetta , Edlund Ulrica , Albertsson Ann‐Christine 
Published: November 2014

ABSTRACTRenewable poly(amidoamine)/hemicellulose hydrogels were prepared from O‐acetylated galactoglucomannan (AcGGM)‐rich biomass and shown to display a significantly high adsorption capacity for Cu2+, Cd2+, Pb2+, Zn2+, Ni2+, Co2+, and
. Two different acrylamido end‐capped poly(amidoamine) oligomers (PAA) were prepared and covalently immobilized onto an in situ formed polysaccharide network via water‐based free radical graft copolymerization and cross‐linking. The synthetic approach was shown to be viable when using a highly purified AcGGM or a crude spruce hydrolysate, an AcGGM and lignin containing biomass fraction as a reactant. Homogeneous reaction mixtures were obtained in both cases with polysaccharide contents up to 20% by weight. Oscillatory shear measurements indicated a predominantly solid‐like behavior of the hydrogels with an increase in shear storage modulus with increasing cross‐link density. The mechanical integrity of the PAA/hemicellulose hydrogels showed higher water swelling capacity and less fragility than the parent PAA hydrogels and they retained the heavy metal ion absorption ability of the PAA component, even in the presence of the least purified hemicellulose fraction. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41695.
Osmoprotective polymer additives attenuate the membrane pore‐forming activity of antimicrobial peptoids
Authors: Smith Peter T. , Huang Mia L. , Kirshenbaum Kent 
Published: November 2014

ABSTRACTAntimicrobial peptides (AMPs) are critical components of the innate immune system and exhibit bactericidal activity against a broad spectrum of bacteria. We investigated the use of N‐substituted glycine peptoid oligomers as AMP mimics with potent antimicrobial activity. The antimicrobial mechanism of action varies among different AMPs, but many of these peptides can penetrate bacterial cell membranes, causing cell lysis. We previously hypothesized that amphiphilic cyclic peptoids may act through a similar pore formation mechanism against methicillin‐resistant Staphylococcus aureus (MRSA). Peptoid‐induced membrane disruption is observed by scanning electron microscopy and results in a loss of membrane integrity. We demonstrate that the antimicrobial activity of the peptoids is attenuated with the addition of polyethylene glycol osmoprotectants, signifying protection from a loss of osmotic balance. This decrease in antimicrobial activity is more significant with larger osmoprotectants, indicating that peptoids form pores with initial diameters of ∼2.0–3.8 nm. The initial membrane pores formed by cyclic peptoid hexamers are comparable in diameter to those formed by larger and structurally distinct AMPs. After 24 h, the membrane pores expand to >200 nm in diameter. Together, these results indicate that cyclic peptoids exhibit a mechanism of action that includes effects manifested at the cell membrane of MRSA. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 227–236, 2015.
Thermal‐ and urea‐induced unfolding processes of glutathione S‐transferase by molecular dynamics simulation
Authors: Li Jiahuang , Chen Yuan , Yang Jie , Hua Zichun 
Published: November 2014

ABSTRACTThe Schistosoma juponicum 26 kDa glutathione S‐transferase (sj26GST) consists of the N‐terminal domain (N‐domain), containing three alpha‐helices (named H1‐H3) and four anti‐parallel beta‐strands (S1‐S4), and the C‐terminal domain (C‐domain), comprising five alpha‐helices (named H4‐H8). In present work, molecular dynamics simulations and fluorescence spectroscopic were used to gain insights into the unfolding process of sj26GST. The molecular dynamics simulations on sj26GST subunit both in water and in 8 M urea were carried out at 300 K, 400 K and 500 K, respectively. Spectroscopic measurements were employed to monitor structural changes. Molecular dynamics simulations of sj26GST subunit induced by urea and temperature showed that the initial unfolding step of sj26GST both in water and urea occurred on N‐domain, involving the disruption of helices H2, H3 and strands S3 and S4, whereas H6 was the last region exposed to solution and was the last helix to unfold. Moreover, simulations analyses combining with fluorescence and circular dichroism spectra indicated that N‐domain could not fold independent, suggesting that correct folding of N‐domain depended on its interactions with C‐domain. We further proposed that the folding of GSTs could begin with the hydrophobic collapse of C‐domain whose H4, H5, H6 and H7 could move close to each other and form a hydrophobic core, especially H6 wrapped in the hydrophobic center and beginning spontaneous formation of the helix. S3, S4, H3, and H2 could form in the wake of the interaction between C‐domain and N‐domain. The paper can offer insights into the molecular mechanism of GSTs unfolding. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 247–259, 2015.
A Green and Sustainable Approach: Celebrating the 30th Anniversary of the Asymmetricl‐Menthol Process
Authors: Emura Makoto , Matsuda Hiroyuki 
Published: November 2014

AbstractTakasagohas been devoted to producingl‐menthol since 1954, and our long history of manufacturing this important aroma chemical is reviewed here. The current asymmetric catalytic process had its 30th anniversary in 2013. Ourl‐menthol process is considered carbon‐neutral, and, therefore, ‘green’ and sustainable. It uses renewable myrcene obtained from gum rosin as a starting material. In addition, the Rh‐BINAP (=2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl) catalytic system is highly efficient. This pathway not only leadsl‐menthol, but a variety of 100% biobased aroma chemical products as well. By measuring the14C levels in a material, one can determine the percentage of carbon that is biobased. This biobased assay, described as the ratio plant‐derived C/fossil‐derived C, can clarify how renewable a product really is. This will be highlighted for several ofTakasago's key aroma chemicals.
Robust, Efficient, and Recyclable Catalysts from the Impregnation of Preformed Dendrimers Containing Palladium Nanoparticles on a Magnetic Support
Authors: Deraedt Christophe , Wang Dong , Salmon Lionel , Etienne Laetitia , Labrugère Christine , Ruiz Jaime , Astruc Didier 
Published: November 2014

AbstractThe simple impregnation of γ‐Fe2O3(core)/SiO2(shell) magnetic nanoparticles with a dendrimer that contains stabilized Pd nanoparticles is presented as a new method to produce highly efficient heterogeneous catalysts. This technique provides much better stability, recyclability, and activity in CC cross‐coupling reactions and selective oxidation of benzyl alcohol to benzaldehyde in water than unsupported Pd nanoparticles.
The Generation Effect: Cavity Accessibility in Dense‐Shell Polyphenylene Dendrimers
Authors: Brutschy Malte , Stangenberg René , Beer Cornelia , Lubczyk Daniel , Baumgarten Martin , Müllen Klaus , Waldvogel Siegfried R. 
Published: November 2014

AbstractSize exclusion is a widespread phenomenon in supra‐ and macromolecular chemistry. Herein, the size exclusion properties of polyphenylene dendrimers on the surface of high fundamental frequency quartz crystal microbalances are reported. For this purpose, a new dense fifth‐generation polyphenylene dendrimer, which was previously not possible owing to the high steric demand of the dendron arms, was synthesized. By increasing the volume and size of subjected analytes an affinity shift from smaller to larger dendrimers can be obtained.
Lipase‐catalyzed synthesis of glucose‐6‐O‐hexanoate in deep eutectic solvents
Authors: Pöhnlein Martin , Ulrich Jonas , Kirschhöfer Frank , Nusser Michael , Muhle‐Goll Claudia , Kannengiesser Bastian , Brenner‐Weiß Gerald , Luy Burkhard , Liese Andreas , Syldatk Christoph , Hausmann Rudolf 
Published: November 2014

Enzymatic synthesis of sugar fatty acid esters in organic solvents is a well‐described procedure to synthesize glycolipids. This study aims at replacing these solvents with deep eutectic solvents (DES), a group of solvents that gained more and more interest during the last years, since they can be easily produced from non‐toxic resources. Enzymatic glycolipid synthesis in deep eutectic solvents was investigated, employing Candida antarctica lipase B (Novozyme 435) in various deep eutectic solvents. A successful lipase‐catalyzed synthesis of glucose fatty acid esters gave proof of this concept, while using the two deep eutectic solvents consisting of choline chloride and urea (CC : U) and choline chloride and glucose (CC : Glc). Additionally the DES consisting of choline chloride and glucose was observed to act as solvent and substrate for the synthesis at the same time.Practical applicationsGlycolipids find applications in many everyday products like cosmetic and pharmaceutical formulations, food and classic cleaning products, utilizing their good detergent or emulsification properties. Glycolipids can, among other routes, be synthesized via lipase‐catalyzed reactions, which are often carried out in organic solvents. By replacing these organic solvents with more ecologically friendly solvents like deep eutectic solvents, the reaction might be improved and the amount of waste produced could be reduced.The lipase‐catalyzed synthesis of glucose‐6‐O‐hexanoate employing glucose and vinyl hexanoate in different deep eutectic solvents was demonstrated within the manuscript.
Enantioselective Epoxidation of Dihydroquinolines by Using Iminium Salt Organocatalysts
Authors: Bulman Page Philip C. , Day David P. , Chan Yohan 
Published: November 2014

AbstractThe first examples of asymmetric epoxidation of dihydroquinoline substrates using iminium salt organocatalysts are reported. The 3,4‐epoxytetrahydroquinoline products are obtained in good yields and with moderate to good enantioselectivities.
Conducting polymer‐based flexible supercapacitor
Authors: Shown Indrajit , Ganguly Abhijit , Chen Li‐Chyong , Chen Kuei‐Hsien 
Published: November 2014

AbstractFlexible supercapacitors, a state‐of‐the‐art material, have emerged with the potential to enable major advances in for cutting‐edge electronic applications. Flexible supercapacitors are governed by the fundamentals standard for the conventional capacitors but provide high flexibility, high charge storage and low resistance of electro active materials to achieve high capacitance performance. Conducting polymers (CPs) are among the most potential pseudocapacitor materials for the foundation of flexible supercapacitors, motivating the existing energy storage devices toward the future advanced flexible electronic applications due to their high redox active‐specific capacitance and inherent elastic polymeric nature. This review focuses on different types of CPs‐based supercapacitor, the relevant fabrication methods and designing concepts. It describes recent developments and remaining challenges in this field, and its impact on the future direction of flexible supercapacitor materials and relevant device fabrications.
Phenolic Metabolites from the Stems and Leaves of Sophora flavescens
Authors: Zhang Chi , Wang Yan‐Min , Zhao Feng‐Chun , Chen Liang‐Mian , Zhang Qi‐Wei , Gao Hui‐Min , Wang Zhi‐Min 
Published: November 2014

AbstractTwo new compounds, (−)‐(6aR,11aR)‐4‐methoxy‐8,9‐(methylenedioxy)pterocarpan 3‐O‐β‐D‐glucopyranoside (1) and 5‐hydroxy‐7‐methoxyisoflavone 4′‐O‐β‐D‐xylopyranosyl‐(1→6)‐β‐D‐glucopyranoside (2), were isolated, together with 30 known compounds from the stems and leaves of Sophora flavescens Aition. Their structures were elucidated by extensive spectroscopic analysis, including HR‐ESI‐MS data. A preliminary comparison of phenolic metabolite profiles, based on the qualitative HPLC analysis, indicated that the composition of the roots and the aerial parts were significantly different.
Terminology Related to the Phenomenon ‘Self‐Disproportionation of Enantiomers’ (SDE)
Authors: Soloshonok Vadim A. , Klika Karel D. 
Published: November 2014

AbstractTerms related to the phenomenon self‐disproportion of enantiomers (SDE) are discussed, particularly with respect to recently suggested alternative terms. Of the numerous terms proffered to describe this phenomenon, it is recommended that the acronym SDE be retained based on its qualities and the fact that its perceived shortcomings are invalid. The term can be readily applied to any process that exhibits the phenomenon of transforming a scalemic sample into fractions containing different enantiomeric compositions in comparison to the enantiomeric composition of the starting sample, and is not restricted solely to chromatographic occurrences. Chromatographic observations, though, can be specifically described by the term enantiomer self‐disproportionation over achiral chromatography (ESDAC). Use of the term homochiral in concert with its intended original meaning is also advocated.
Attenuating noise from computed tomography medical images using a coefficients‐driven total variation denoising algorithm
Authors: Al‐Ameen Zohair , Sulong Ghazali 
Published: November 2014

ABSTRACTThe aim of image denoising is to recover a visually accepted image from its noisy observation with as much detail as possible. The noise exists in computed tomography images due to hardware errors, software faults and/or low radiation dose. Because of noise, the analysis and extraction of accurate medical information is a challenging task for specialists. Therefore, a novel modification on the total variational denoising algorithm is proposed in this article to attenuate the noise from CT images and provide a better visual quality. The newly developed algorithm can properly detect noise from the other image components using four new noise distinguishing coefficients and reduce it using a novel minimization function. Moreover, the proposed algorithm has a fast computation speed, a simple structure, a relatively low computational cost and preserves the small image details while reducing the noise efficiently. Evaluating the performance of the proposed algorithm is achieved through the use of synthetic and real noisy images. Likewise, the synthetic images are appraised by three advanced accuracy methods –Gradient Magnitude Similarity Deviation (GMSD), Structural Similarity (SSIM) and Weighted Signal‐to‐Noise Ratio (WSNR). The empirical results exhibited significant improvement not only in noise reduction but also in preserving the minor image details. Finally, the proposed algorithm provided satisfying results that outperformed all the comparative methods.
Improved resolution of 3D printed scaffolds by shrinking
Authors: Chia Helena N. , Wu Benjamin M. 
Published: November 2014

AbstractThree‐dimensional printing (3DP) uses inkjet printheads to selectively deposit liquid binder to adjoin powder particles in a layer‐by‐layer fashion to create a computer‐modeled 3D object. Two general approaches for 3DP have been described for biomedical applications (direct and indirect 3DP). The two approaches offer competing advantages, and both are limited by print resolution. This study describes a materials processing strategy to enhance 3DP resolution by controlled shrinking net‐shape scaffolds. Briefly, porogen preforms are printed and infused with the desired monomer or polymer solution. After solidification or polymerization, the porogen is leached and the polymer is allowed to shrink by controlled drying. Heat treatment is performed to retain the dimensions against swelling forces. The main objective of this study is to determine the effects of polymer content and post‐processing on dimension, microstructure, and thermomechanical properties of the scaffold. For polyethylene glycol diacrylate (PEG‐DA), reducing polymer content corresponded with greater shrinkage with maximum shrinkage of ∼80 vol% at 20% vol% PEG‐DA. The secondary heat treatment retains the microarchitecture and new dimensions of the scaffolds, even when the heat‐treated scaffolds are immersed into water. To demonstrate shrinkage predictability, 3D components with interlocking positive and negative features were printed, processed, and fitted. This material processing strategy provides an alternative method to enhance the resolution of 3D scaffolds, for a wide range of polymers, without optimizing the binder‐powder interaction physics to print each material combination. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1415–1423, 2015.
Anti-Sclerostin Antibody Treatment in a Rat Model of Progressive Renal Osteodystrophy
Authors: Moe Sharon M , Chen Neal X , Newman Christopher L , Organ Jason M , Kneissel Michaela , Kramer Ina , Gattone Vincent H , Allen Matthew R 
Published: November 2014

ABSTRACT

Chronic kidney disease (CKD) is associated with abnormalities in bone quantity and quality, leading to increased fractures. Recent studies suggest abnormalities of Wnt signaling in animal models of CKD and elevated sclerostin levels in patients with CKD. The goal of this study was to evaluate the effectiveness of anti-sclerostin antibody treatment in an animal model of progressive CKD with low and high parathyroid hormone (PTH) levels. Cy/+ male rats (CKD) were treated without or with calcium in the drinking water at 25 weeks of age to stratify the animals into high PTH and low PTH groups, respectively, by 30 weeks. Animals were then treated with anti-sclerostin antibody at 100 mg/kg i.v. weekly for 5 doses, a single 20-µg/kg subcutaneous dose of zoledronic acid, or no treatment, and were then euthanized at 35 weeks. As a positive control, the efficacy of anti-sclerostin antibody treatment was also evaluated in normal littermates. The results demonstrated that the CKD animals with high PTH had lower calcium, higher phosphorus, and lower FGF23 compared to the CKD animals with low PTH. Treatment with anti-sclerostin antibody had no effect on any of the biochemistries, whereas zoledronic acid lowered dkk-1 levels. The anti-sclerostin antibody increased trabecular bone volume/total volume (BV/TV) and trabecular mineralization surface in animals with low PTH, but not in animals with high PTH. Neither anti-sclerostin antibody nor zoledronic acid improved biomechanical properties in the animals. Cortical porosity was severe in high-PTH animals and was unaffected by either treatment. In contrast, in normal animals treated with anti-sclerostin antibody, there was an improvement in bone volume, cortical geometry, and biomechanical properties. In summary, this is the first study to test the efficacy of anti-sclerostin antibody treatment on animals with advanced CKD. We found efficacy in improving bone properties only when the PTH levels were low. © 2014 American Society for Bone and Mineral Research
Bisphosphonates for the Prevention of Fractures in Osteogenesis Imperfecta: Meta-Analysis of Placebo-Controlled Trials
Authors: Hald Jannie D , Evangelou Evangelos , Langdahl Bente L , Ralston Stuart H 
Published: November 2014

ABSTRACT

Bisphosphonates are widely used off-label in the treatment of patients with osteogenesis imperfecta (OI) with the intention of reducing the risk of fracture. Although there is strong evidence that bisphosphonates increase bone mineral density in osteogenesis imperfecta, the effects on fracture occurrence have been inconsistent. The aim of this study was to gain a better insight into the effects of bisphosphonate therapy on fracture risk in patients with osteogenesis imperfecta by conducting a meta-analysis of randomized controlled trials in which fractures were a reported endpoint. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials in which the effects of bisphosphonates on fracture risk in osteogenesis imperfecta were compared with placebo and conducted a meta-analysis of these studies using standard methods. Heterogeneity was assessed using the I2 statistic. Six eligible studies were identified involving 424 subjects with 751 patient-years of follow-up. The proportion of patients who experienced a fracture was not significantly reduced by bisphosphonate therapy (Relative Risk [RR] = 0.83 [95% confidence interval 0.69–1.01], p = 0.06) with no heterogeneity between studies (I2 = 0). The fracture rate was reduced by bisphosphonate treatment when all studies were considered (RR = 0.71 [0.52–0.96], p = 0.02), but with considerable heterogeneity (I2 = 36%) explained by one study where a small number of patients in the placebo group experienced a large number of fractures. When this study was excluded, the effects of bisphosphonates on fracture rate was not significant (RR = 0.79 [0.61–1.02], p = 0.07, I2 = 0%). We conclude that the effects of bisphosphonates on fracture prevention in osteogenesis imperfecta are inconclusive. Adequately powered trials with a fracture endpoint are needed to further investigate the risks and benefits of bisphosphonates in this condition. © 2014 American Society for Bone and Mineral Research.
MiR-497∼195 Cluster MicroRNAs Regulate Osteoblast Differentiation by Targeting BMP Signaling
Authors: Grünhagen Johannes , Bhushan Raghu , Degenkolbe Elisa , Jäger Marten , Knaus Petra , Mundlos Stefan , Robinson Peter N , Ott Claus-Eric 
Published: November 2014

ABSTRACT

MicroRNAs play important roles during cell reprogramming and differentiation. In this study, we identified the miR-497∼195 cluster, a member of the miR-15 family, as strongly upregulated with age of postnatal bone development in vivo and late differentiation stages of primary osteoblasts cultured in vitro. Early expression of miR-195–5p inhibits differentiation and mineralization. Microarray analyses along with quantitative PCR demonstrate that miR-195–5p alters the gene regulatory network of osteoblast differentiation and impairs the induction of bone morphogenetic protein (BMP) responsive genes. Applying reporter gene and Western blot assays, we show that miR-195–5p interferes with the BMP/Smad-pathway in a dose-dependent manner. Systematically comparing the changes in mRNA levels in response to miR-195–5p overexpression with the changes observed in the natural course of osteoblast differentiation, we demonstrate that microRNAs of the miR-15 family affect several target genes involved in BMP signaling. Predicted targets including Furin, a protease that cleaves pro-forms, genes encoding receptors such as Acvr2a, Bmp1a, Dies1, and Tgfbr3, molecules within the cascade like Smad5, transcriptional regulators like Ski and Zfp423 as well as Mapk3 and Smurf1 were validated by quantitative PCR. Taken together, our data strongly suggest that miR-497∼195 cluster microRNAs act as intracellular antagonists of BMP signaling in bone cells. © 2014 American Society for Bone and Mineral Research.
Permanents and Determinants of Latin Squares
Authors: Donovan Diane , Johnson Kenneth , Wanless Ian M. 
Published: November 2014

AbstractLet L be a latin square of indeterminates. We explore the determinant and permanent of L and show that a number of properties of L can be recovered from the polynomials and per(L). For example, it is possible to tell how many transversals L has from per(L), and the number of 2 × 2 latin subsquares in L can be determined from both and per(L). More generally, we can diagnose from or per(L) the lengths of all symbol cycles. These cycle lengths provide a formula for the coefficient of each monomial in and per(L) that involves only two different indeterminates. Latin squares A and B are trisotopic if B can be obtained from A by permuting rows, permuting columns, permuting symbols, and/or transposing. We show that nontrisotopic latin squares with equal permanents and equal determinants exist for all orders that are divisible by 3. We also show that the permanent, together with knowledge of the identity element, distinguishes Cayley tables of finite groups from each other. A similar result for determinants was already known.