bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chondrocyte redifferentiation and construct mechanical property development in single‐component photocrosslinkable hydrogels
Authors: Levett Peter A. , Melchels Ferry P. W. , Schrobback Karsten , Hutmacher Dietmar W. , Malda Jos , Klein Travis J. 
Published: August 2013

AbstractHydrogels are promising materials for cartilage repair, but the properties required for optimal functional outcomes are not yet known. In this study, we functionalized four materials that are commonly used in cartilage tissue engineering and evaluated them using in vitro cultures. Gelatin, hyaluronic acid, polyethylene glycol, and alginate were functionalized with methacrylic anhydride to make them photocrosslinkable. We found that the responses of encapsulated human chondrocytes were highly dependent on hydrogel type. Gelatin hydrogels supported cell proliferation and the deposition of a glycosaminoglycan rich matrix with significant mechanical functionality. However, cells had a dedifferentiated phenotype, with high expression of collagen type I. Chondrocytes showed the best redifferentiation in hyaluronic acid hydrogels, but the newly formed matrix was highly localized to the pericellular regions, and these gels degraded rapidly. Polyethylene glycol hydrogels, as a bioinert control, did not promote any strong responses. Alginate hydrogels did not support the deposition of new matrix, and the stiffness decreased during culture. The markedly different response of chondrocytes to these four photocrosslinkable hydrogels demonstrates the importance of material properties for chondrogenesis and extracellular matrix production, which are critical for effective cartilage repair. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2544–2553, 2014.
Transmenopausal Changes in Trabecular Bone Quality
Authors: Gamsjaeger Sonja , Brozek Wolfgang , Recker Robert , Klaushofer Klaus , Paschalis Eleftherios P 
Published: August 2013

ABSTRACT

Bone strength depends on its amount and quality. Bone quality includes its structural and material properties. Bone material properties are dependent on bone turnover rates. Remodeling rates are significantly increased immediately after menopause. In the present study, we used Raman microspectroscopic analysis of double iliac crest biopsies with a spatial resolution of 1 µm obtained before and immediately after menopause (1 year after cessation of menses) in healthy females to investigate changes in material properties attributable to menopause. In particular, the mineral/matrix ratio, the relative proteoglycan and lipid content, the mineral maturity/crystallinity, and the relative pyridinoline collagen cross-link content were determined in trabecular bone as a function of surface metabolic activity and tissue age. The results indicate that significant changes (specifically in mineral/matrix ratio) were evident at active bone forming surfaces, whereas the relative proteoglycan content was altered at resorbing surfaces. These changes were not accompanied by altered mineral content or quality as monitored by Raman microspectroscopic analysis. © 2014 American Society for Bone and Mineral Research.
The 51 kDa FADS3 is Secreted in the ECM of Hepatocytes and Blood in Rat
Authors: Blanchard Hélène , Boulier‐Monthéan Nathalie , Legrand Philippe , Pédrono Frédérique 
Published: August 2013

ABSTRACTThe fatty acid desaturase (Fads) cluster is composed of three genes encoding for the Δ5‐ and Δ6‐desaturases and FADS3. The two former proteins are involved in the fatty acid biosynthesis; the latter one shares a high sequence identity but has still no attributed function. In a previous work performed in rat, we described three isoforms of FADS3 expressed in a tissue‐dependent manner. In the present study, we demonstrated a specific subcellular targeting depending on the isoform. In cultured hepatocytes, which mainly expressed the 51 kDa protein, FADS3 was unexpectedly present in the cytosolic fraction, but was also secreted in the extracellular matrix on fibronectin‐containing fibers. The secretion pathway was investigated and we determined the presence of exosome‐like vesicles on the FADS3‐stained fibers. In parallel, FADS3 was detected in blood of hepatic vessel, and particularly in serum. In conclusion, this study demonstrated a very specific intra‐ and extracellular location of FADS3 in comparison with the Δ5‐ and Δ6‐desaturases, suggesting a unique function for this putative desaturase, even if no activity has been yet identified neither in the extracellular matrix of hepatocytes nor in serum. J. Cell. Biochem. 115: 199–207, 2014. © 2013 Wiley Periodicals, Inc.
Influence of hydrodynamic shear on performance and microbial community structure of a hybrid anaerobic reactor
Authors: Kundu Kankana , Bergmann Ingo , Klocke Michael , Sharma Shilpi , Sreekrishnan Trichur Ramaswamy 
Published: August 2013

AbstractBACKGROUNDHydrodynamic shear plays a major role in the formation, maintenance, structure, and metabolism of self‐immobilized microbial communities in reactors. The study attempts to correlate the performance and microbial community structure of granular sludge in a mesophilic hybrid anaerobic reactor under different upflow velocities to fluidize the bed. The reactor was started with an initial upflow velocity of 4 m h‐1, which was increased gradually till system deterioration to observe its effect on granule size, reactor performance, and microbial community structure. Monte Carlo method was used to quantify hydrodynamic shear range at different upflow velocities using a modified Ergun equation for the respective ranges of granule size.RESULTSUp to 6 m h‐1 performance was positively affected, but beyond this upflow velocity, the system started showing reduced performance and completely deteriorated at 10 m h‐1. Significant reduction in the abundance and diversity of both Archaea and Bacteria was observed. Among all methanogenic groups, Methanosaetaceae was most severely affected due to breakage and wash out of granules.CONCLUSIONIt can be concluded that hydrodynamic shear can be employed as a sensitive control parameter to improve reactor performance, and a specified range should be determined experimentally to avoid negative influences associated with this. © 2013 Society of Chemical Industry
Counting Independent Sets of a Fixed Size in Graphs with a Given Minimum Degree
Authors: Engbers John , Galvin David 
Published: August 2013

AbstractGalvin showed that for all fixed δ and sufficiently large n, the n‐vertex graph with minimum degree δ that admits the most independent sets is the complete bipartite graph . He conjectured that except perhaps for some small values of t, the same graph yields the maximum count of independent sets of size t for each possible t. Evidence for this conjecture was recently provided by Alexander, Cutler, and Mink, who showed that for all triples with , no n‐vertex bipartite graph with minimum degree δ admits more independent sets of size t than . Here, we make further progress. We show that for all triples with and , no n‐vertex graph with minimum degree δ admits more independent sets of size t than , and we obtain the same conclusion for and . Our proofs lead us naturally to the study of an interesting family of critical graphs, namely those of minimum degree δ whose minimum degree drops on deletion of an edge or a vertex.
Interval Non‐edge‐Colorable Bipartite Graphs and Multigraphs
Authors: Petrosyan Petros A. , Khachatrian Hrant H. 
Published: August 2013

AbstractAn edge‐coloring of a graph G with colors is called an interval t‐coloring if all colors are used, and the colors of edges incident to any vertex of G are distinct and form an interval of integers. In 1991, Erdős constructed a bipartite graph with 27 vertices and maximum degree 13 that has no interval coloring. Erdős's counterexample is the smallest (in a sense of maximum degree) known bipartite graph that is not interval colorable. On the other hand, in 1992, Hansen showed that all bipartite graphs with maximum degree at most 3 have an interval coloring. In this article, we give some methods for constructing of interval non‐edge‐colorable bipartite graphs. In particular, by these methods, we construct three bipartite graphs that have no interval coloring, contain 20, 19, 21 vertices and have maximum degree 11, 12, 13, respectively. This partially answers a question that arose in [T.R. Jensen, B. Toft, Graph coloring problems, Wiley Interscience Series in Discrete Mathematics and Optimization, 1995, p. 204]. We also consider similar problems for bipartite multigraphs.
On Generalized Ramsey Numbers for 3‐Uniform Hypergraphs
Authors: Dudek Andrzej , Mubayi Dhruv 
Published: August 2013

AbstractThe well‐known Ramsey number is the smallest integer n such that every ‐free graph of order n contains an independent set of size u. In other words, it contains a subset of u vertices with no K2. Erdős and Rogers introduced a more general problem replacing K2 by for . Extending the problem of determining Ramsey numbers they defined the numbers

urn:x-wiley:03649024:media:jgt21760:jgt21760-math-0005where the minimum is taken over all ‐free graphs G of order n. In this note, we study an analogous function for 3‐uniform hypergraphs. In particular, we show that there are constants c1 and c2 depending only on s such that

urn:x-wiley:03649024:media:jgt21760:jgt21760-math-0008
Autologous solution protects bovine cartilage explants from IL‐1α‐ and TNFα‐induced cartilage degradation
Authors: Matuska Andrea , O'shaughnessey Krista , King William , Woodell‐May Jennifer 
Published: August 2013

AbstractOsteoarthritis (OA) is characterized by deterioration of articular cartilage driven by an imbalance of pro‐ and anti‐inflammatory cytokines. To address the cartilage deterioration observed in OA, an autologous protein solution (APS) has been developed which has been shown to inhibit the production of destructive proteases and inflammatory cytokines from chondrocytes and monocytes, respectively. The purpose of this study was to determine the chondroprotective effect of APS on IL‐1α‐ or TNFα‐challenged bovine articular cartilage explants. Cartilage explants were cultured in the presence or absence of recombinant inflammatory cytokines, IL‐1α and TNFα. Explants under equivalent inflammatory conditions were pretreated with recombinant antagonists IL‐1ra, sTNF‐RI, or APS to measure their inhibition of matrix degradation. Explants were further evaluated with Safranin‐O, Masson's Trichrome, and Hematoxylin and Eosin histological staining. APS was more effective than recombinant antagonists in preventing cartilage matrix degradation and inhibited any measurable IL‐1α‐induced collagen release over a 21‐day culture period. APS treatment reduced the degree of Safranin‐O staining loss when cartilage explants were cultured with IL‐1α or TNFα. Micrographs of APS treated cartilage explants showed an increase in observed cellularity and apparent cell division. APS may have the potential to prevent cartilage loss associated with early OA. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1929–1935, 2013
Thermal stability of liquid antioxidative extracts from pomegranate peel
Authors: Qu Wenjuan , Li Pingping , Hong Jihua , Liu Zhiling , Chen Yufang , Breksa Andrew P , Pan Zhongli 
Published: August 2013

AbstractBACKGROUNDLiquid extracts from pomegranate peel have the potential for use as natural antioxidant products. This study investigates the quality changes of liquid extracts before and after thermal treatment during sterilization and storage. Liquid pomegranate peel extracts were prepared, sterilized under ultra‐high temperature (UHT) at 121 °C for 10 s and then stored at three temperatures (4, 25 and 37 °C) for up to 180 days. The industrial, color, UV‐visible spectrum profile and antioxidant (phenolics) characteristics were measured.RESULTSThermal sterilization treatment had no negative effects on the industrial, color, spectral and antioxidant characteristics of the extracts. After 180 days, the extracts stored at 4 °C retained 67% of the initial total soluble phenolic content and 58% of the original scavenging activity. The major antioxidant components in the extracts (stored at 4 °C for 180 days) were gallic acid, punicalagin A, punicalagin B and ellagic acid having concentrations of 19.3, 197.2, 221.1 and 92.4 mg L−1, respectively.CONCLUSIONThe results show that liquid pomegranate peel extracts had acceptable thermal stability after sterilization and storage. The recommended storage condition of this product was low temperature. © 2013 Society of Chemical Industry
The Role of Knowledge Intermediaries in the Management of Experience Knowledge
Authors: Franssila Heljä 
Published: August 2013

Effectively collecting, sharing and cultivating experience‐based knowledge in work organisations is demanding. As the challenges are getting more intensive, there is a need for dedicated personnel who are able to steer, enable and support knowledge sharing activities. In the knowledge management literature, these types of individuals may be characterised as knowledge intermediaries.This paper presents results from an empirical study of an inquiry into the work tasks of knowledge intermediaries. The study focused on exploring the challenges and demands knowledge intermediaries experienced in enabling experience knowledge sharing and reuse. The study was conducted in two industrial enterprises that both manufacture complex machinery products and provide after sales installation and maintenance services for the machines at clients' sites. Empirical data were collected through interviews with technical support personnel who serve as knowledge intermediaries in after sales services.The study analyses and describes prototypical activity episodes that illustrate the nature of knowledge intermediary work and the information interaction challenges faced in their work. Typical demands and challenges for the management of experience knowledge include the following: (i) problem space assembly and narrowing in urgent support request situations; (ii) assembly of the hidden experience‐based knowledge; and (iii) new component and product knowledge acquisition and updating. The paper contributes to the understanding of the needs for and practices of knowledge intermediaries, and it offers some guidelines for the enhancement of experience knowledge sharing in workplaces. Copyright © 2013 John Wiley & Sons, Ltd.
The Viscosity Law of Dendronized Linear Polymers
Authors: Zhang Baozhong , Kroeger Anja , Schlüter A. Dieter , Wegner Gerhard 
Published: August 2013

The intrinsic viscosity [η] of dendronized linear macromolecules dissolved in thermodynamically good solvents depends both on chain length that is contour length Lc of the backbone of the polymer and on the persistence length lp. Investigating a set of samples of identical Lc but differing in the generation number for which data on lp are available, it becomes possible to establish a generalized viscosity law in the form [η] = K(M/Mp)α in which Mp denotes the molar mass of the objects per lp, M is the total molar mass, K is a constant, and α is the Mark–Howink exponent, which is found to be 0.55.
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Maternal vitamin D deficiency causes smaller muscle fibers and altered transcript levels of genes involved in protein degradation, myogenesis, and cytoskeleton organization in the newborn rat
Authors: Max Daniela , Brandsch Corinna , Schumann Sarah , Kühne Hagen , Frommhagen Matthias , Schutkowski Alexandra , Hirche Frank , Staege Martin S. , Stangl Gabriele I. 
Published: August 2013

ScopeEpidemiologic data reveal associations between low serum concentrations of 25‐hydroxyvitamin D (25(OH)D) and higher risk of falls and muscle weakness. Fetal stage is critical for the development of skeletal muscle, but little information is available on the impact of maternal vitamin D deficiency on muscles of offspring.Methods and resultsTo investigate the morphology and transcriptome of gastrocnemius muscle in newborns in response to maternal vitamin D deficiency, 14 female rats were fed either a vitamin D3 deficient (0 IU/kg) or a vitamin D3 adequate diet (1000 IU/kg) 8 weeks prior to conception, during pregnancy, and lactation. Analysis of cholecalciferol, 25(OH)D3 and 1,25‐dihydroxyvitamin D3 show that dams fed the vitamin D deficient diet and their newborns suffered from a relevant vitamin D deficiency. Muscle cells of vitamin D deficient newborns were smaller than those of vitamin D adequate newborns (p < 0.05). Muscle transcriptome of the newborns revealed 426 probe sets as differentially expressed (259 upregulated, 167 downregulated) in response to vitamin D deficiency (fold change ≥1.5, p < 0.05). The effected genes are involved in protein catabolism, cell differentiation and proliferation, muscle cell development, and cytoskeleton organization.ConclusionMaternal vitamin D deficiency has a major impact on morphology and gene expression profile of skeletal muscle in newborns.
Selective Extraction of N‐Heterocyclic Precursors of 1,3,5,7‐Tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX) Using Molecularly Imprinted Polymers
Authors: Wang Lei , Xu Zhi‐Bin , Wang Peng , Xue Min , Dong Xue‐Min , Meng Zi‐Hui , Lou Zhong‐Liang , Lin Zhi‐Hui , Lu Cheng‐Yi 
Published: August 2013

AbstractN‐heterocyclic compounds are key nitration precursors for some high energy density explosives such as 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX). Nitration of 1,3,5,7‐tetraacetyl‐1,3,5,7‐tetraazacyclooctane (TAT) yields HMX in high yields and purity. However, the analogue 1,3,5‐triacetyl‐1,3,5‐triazacyclohexane (TRAT) is easily co‐produced via the condensation of acetonitrile and 1,3,5‐trioxan. To selectively extract TAT from a mixture of TAT and TRAT, the molecular imprinting technology (MIT) was developed in this study. The capacity of the dry polymer is 16 mg g−1 and the recovery surpasses 75 %.
Synthesis and Characterization of Mono‐, Di‐, and Tetranitrated 7,8‐Disubstituted Glycolurils
Authors: Sherrill William M. , Johnson Eric C. , Paraskos Alexander J. 
Published: August 2013

AbstractThree 7,8‐disubstitited glycolurils were synthesized and subjected to various nitration conditions yielding the corresponding mono‐, di‐, and tetranitro derivatives. Prior to their synthesis, these nitrated compounds were evaluated computationally to determine their densities and heats of formation, from which explosive performance was predicted. Details on the methods used for the synthesis as well as the results from their computational analysis are discussed.
Conformational stability of CopC and roles of residues Tyr79 and Trp83
Authors: Song Zhen , Zheng Xiaoyan , Yang Binsheng 
Published: August 2013

AbstractCopC is a periplasmic copper Chaperone protein that has a β‐barrel fold and two metal‐binding sites distinct for Cu(II) and Cu(I). In the article, four mutants (Y79F, Y79W, Y79WW83L, Y79WW83F) were obtained by site‐directed mutagenesis. The far‐UV CD spectra of the proteins were similar, suggesting that mutations did not bring any significant changes in secondary structures. Meanwhile the effects of mutations on the protein's function were manifested by Cu(II) binding. Fluorescence lifetime measurement and quenching of tryptophan fluorescence by acrylamide and KI showed that the microenvironment around Trp83 was more hydrophobic than that around Tyr79 in apoCopC. Unfolding experiments induced by guanidinium chloride (GdnHCl), urea provided the conformational stability of each protein. The Δ<ΔG0element> obtained using the model of structural elements was used to show the role of Tyr79 and Trp83. On the one hand, the <ΔG0element> induced by urea for Y79F, Y79W have a loss of 6.51, 2.03 kJ/mol, respectively, compared with apoCopC, proving that replacement of Tyr79 by Phe or Trp all decreased the protein stability, meaning that the hydrogen bonds interactions between Tyr79 and Thr75 played an important role in stabilizing apoCopC. On the other hand, the <ΔG0element> induced by urea for Y79WW83L have a loss of 11.44 kJ/mol, but for Y79WW83F did a raise of 1.82 kJ/mol compared with Y79W. The replacement of Trp83 by Phe and Leu yields opposite effects on protein stability, which suggested that the aromatic ring of Trp83 was important in maintaining the hydrophobic core of apoCopC.
Insecticidal activity of pogostone against Spodoptera litura and Spodoptera exigua (Lepidoptera: Noctuidae)
Authors: Huang Si‐Han , Xian Ji‐Dong , Kong Song‐Zhi , Li Yu‐Cui , Xie Jian‐Hui , Lin Ji , Chen Jian‐Nan , Wang Hong‐Feng , Su Zi‐Ren 
Published: August 2013

AbstractBACKGROUNDEssential oil of Pogostemon cablin (Blanco) Benth. has been reported to exhibit strong insecticidal activities, but few studies have focused on the insecticidal activity of its main individual constituent, pogostone (PO). The goal of this research was to investigate the insecticidal activity of PO against two harmful noctuid insects, Spodoptera litura (Fabricius) and Spodoptera exigua (Hübner).RESULTSIn a no‐choice assay, PO exhibited strong antifeedant activity against S. litura and S. exigua. PO showed pronounced larvicidal activities, including oral toxicity (LC50 986.88 mg L−1 and 545.61 mg L−1 respectively) and contact toxicity (LC50 1041.42 mg L−1 and 519.48 mg L−1 respectively) against these two noctuid insects. Additionally, PO treatment significantly increased the larval and pupal developmental period. Furthermore, PO showed moderate ovicidal activities and influenced the emergence and deformity of the moth. However, PO failed to exert a potent effect on adult development. These tested parameters proved to be dose dependent for both insect species.CONCLUSIONPO possesses strong insecticidal activities, especially antifeedant, larvicidal, growth inhibitory and pupicidal activities, against S. litura and S. exigua. PO may partly account for the insecticidal activity of patchouli oil and may be a promising candidate for the control of agricultural insects. © 2013 Society of Chemical Industry
Power spectrum of electronic heat current fluctuations
Authors: Zhan Fei , Denisov Sergey , Hänggi Peter 
Published: August 2013

We analyze the fluctuations of an electronic thermal current across an idealized molecular junction. The focus here will be on the spectral features of the resulting heat fluctuations. By use of the Green function method we derive an explicit expression for the frequency‐dependent power spectral density of the emerging energy fluctuations. The complex expression simplifies considerably in the limit of zero frequency, yielding the noise intensity of the heat current. The spectral density for the electronic heat fluctuations still depends on the frequency in the zero‐temperature limit, assuming different asymptotic behaviors in the low‐ and high‐frequency regions. We further address subtleties and open problems from an experimental view point for measurements of frequency‐dependent power spectral densities.Sketch of a molecular junction setup used in the text. The average heat flow is generated by electrons moving from a hot electrode across the molecular junction towards a neighboring cold electrode . The inter‐electrode electronic level can be tuned continuously.