bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradable natural polymer hydrogels for articular cartilage tissue engineering
Authors: Zhao Wen , Jin Xing , Cong Yang , Liu Yuying , Fu Jun
Published: November 2012

Articular cartilage has poor ability to heal once damaged. Tissue engineering with scaffolds of polymer hydrogels is promising for cartilage regeneration and repair. Polymer hydrogels composed of highly hydrated crosslinked networks mimic the collagen networks of the cartilage extracellular matrix and thus are employed as inserts at cartilage defects not only to temporarily relieve the pain but also to support chondrocyte proliferation and neocartilage regeneration. The biocompatibility, biofunctionality, mechanical properties, and degradation of the polymer hydrogels are the most important parameters for hydrogel‐based cartilage tissue engineering. Degradable biopolymers with natural origin have been widely used as biomaterials for tissue engineering because of their outstanding biocompatibility, low immunological response, low cytotoxicity, and excellent capability to promote cell adhesion, proliferation, and regeneration of new tissues. This review covers several important natural proteins (collagen, gelatin, fibroin, and fibrin) and polysaccharides (chitosan, hyaluronan, alginate and agarose) widely used as hydrogels for articular cartilage tissue engineering. The mechanical properties, structures, modification, and structure–performance relationship of these hydrogels are discussed since the chemical structures and physical properties dictate the in vivo performance and applications of polymer hydrogels for articular cartilage regeneration and repair. © 2012 Society of Chemical Industry
Morphology and SSU rRNA gene‐based phylogeny of two Diophrys‐like ciliates from northern china, with notes on morphogenesis of Pseudodiophrys nigricans (Protozoa, Ciliophora)
Authors: Fan Yangbo , Warren Alan , Al‐Farraj Saleh A. , Chen Xumiao , Shao Chen
Published: November 2012

Two free‐living marine euplotid ciliates, Pseudodiophrys nigricans and Diophrys japonica, collected from the coastal waters off Qingdao, northern China, were investigated using live observations and protargol impregnation methods. The cortical development of P. nigricans was observed during binary division. Although its general pattern of morphogenesis is similar to that of other Diophrys‐like species, three unusual features are noteworthy: 1) the frontoventral transverse cirral anlagen develop in the secondary mode, similar to that of Euplotes; 2) the undulating membrane anlage migrates far from the cytostome and does not split into two membranes; and 3) the parental adoral zone of membranelles remains nearly intact throughout the entire morphogenetic process. Diophrys japonica is redescribed based on a Chinese population and can be recognized by having one left marginal cirrus, densely arranged cortical granules, and a fragment kinety with three dikinetids. Phylogenetic analyses based on the small subunit rRNA (SSU rRNA) gene sequence data indicate that D. japonica is placed within the Diophrys clade and is most closely related to the well‐known D. apoligothrix. © J. Morphol., 2013. © 2012 Wiley Periodicals, Inc.
Similar growth plate morphology in stapling and tension band plating hemiepiphysiodesis: A porcine experimental histomorphometric study
Authors: Gottliebsen Martin , Rahbek Ole , Poulsen Hanne Damgaard , Møller‐Madsen Bjarne
Published: November 2012

The tension band plating technique for hemiepiphysiodesis is new and advocated because it is believed to reduce the risk of premature closure of the growth plate compared to stapling. The benefit of the tension band plating technique has not yet been proven in experimental or randomized clinical studies. Ten weeks old domestic pigs in two randomized, paired studies were used. Right proximal tibia was randomized to medial epiphysiodesis by either stapling or tension band plating. Left side received the opposite treatment. Study A (n = 10): 9 weeks treatment. Study B (n = 8): implant removal after 9 weeks of treatment and 5 weeks of housing. Fractions of the chondrocyte layers were determined using quantitative histomorphometry. Mean heights of the growth plates were measured. No significant changes were observed between histomorphometric parameters in neither study A or B. Areas with disorganized cartilage tissue were abundant in 13/16 samples from study B and observed after both treatment with tension band plating and staples. Chondrocyte zone fractions did not differ between tension band plating and staple treatment in this randomized, paired animal study. The growth plate responded to release of hemiepiphysiodesis with abundant disorganized cartilage tissue in both groups. The histological response to hemiepiphysiodesis by tension band plating and staples appear to be similar. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 574–579, 2013
Ectomycorrhizal‐fungal colonization induces physio‐morphological changes in Quercus serrata leaves and roots
Authors: Makita Naoki , Hirano Yasuhiro , Yamanaka Takashi , Yoshimura Kenichi , Kosugi Yoshiko
Published: November 2012

To determine how colonization by different ectomycorrhizal (ECM)‐fungal species affects the physiology and morphology of Quercus serrata seedlings, we assessed the net photosynthetic rate, the respiration rate of the lateral roots, leaf and root nitrogen (N) concentrations, specific leaf area, and specific root length in 9‐month‐old Q. serrata seedlings inoculated with Pisolithus tinctorius, Scleroderma citrinum, Laccaria amethystea, and Astraeus hygrometricus. While uninoculated control plants showed no colonization, the percentage of ECM colonization of root tips attained 35% with P. tinctorius and about 86% with the other three ECM species. Similar to ECM root colonization, the photosynthetic as well as the root‐respiration rates were higher in seedlings with S. citrinum, L. amethystea, and A. hygrometricus than that in the control and those with P. tinctorius. Both the photosynthetic and root‐respiration rates were positively correlated with ECM‐fungal colonization. Similar trends were observed for the N concentration, specific leaf area, and specific root length, which differed significantly among ECM‐fungal species and were related with ECM‐fungal colonization. The results suggest that both physiological and morphological traits are specific to ECM‐fungal species. As Q. serrata seedlings with high colonization can exhibit better resource‐acquisition ability, the identification of strongly colonizing ECM‐fungal species is essential. Comparisons with high‐ and low‐colonizing ECM‐fungal species improve our understanding of source–sink relationships in carbon allocation of forest tree species.
Classification of rice genotypes based on their mechanisms of adaptation to iron toxicity
Authors: Engel Katrin , Asch Folkard , Becker Mathias
Published: November 2012

Iron (Fe) toxicity is a nutritional disorder that affects lowland rice (Oryza sativa L.). The occurrence of excessive amounts of reduced Fe(II) in the soil solution, its uptake by the rice roots, and its transpiration‐driven transport result in elevated Fe(II) concentrations in leaf cells that catalyze the formation of reactive oxygen species. The oxidative stress causes rusty brown spots on leaves (bronzing) and the reduction of biomass and yield. While the use of resistant genotypes is the most promising approach to address the problem, the stress appears to differentially affect rice plants as a function of plant age, climatic conditions, stress intensity and duration, and the prevailing adaptation mechanism. We comparatively assessed 21 contrasting 6‐week‐old rice genotypes regarding their response (symptom score, biomass, Fe concentrations and uptake) to a 6 d iron pulse of 1500 mg L–1 Fe(II). Eight selected genotypes were further compared at different stress intensities (0, 500, 1000, and 1500 mg L–1 Fe(II)) and at different developmental stages (4‐, 6‐, and 8‐week‐old plants). Based on Fe‐induced biomass reduction and leaf‐bronzing score, the tested spectrum was grouped in resistant and sensitive genotypes. Linking bronzing scores to leaf iron concentrations allowed further differentiation into includer and excluder types. Iron precipitation on roots and organ‐specific iron partitioning permitted to classify the adaptation strategies into root exclusion, stem and leaf sheath retention, and leaf blade tissue tolerance. The effectiveness of these strategies differed with stress intensity and developmental stage. The reported findings improve the understanding of Fe‐stress response and provide a basis for future genotype selection or breeding for enhancing Fe‐toxicity resistance in rice.
Yield promotion and phosphorus solubilization by plant growth–promoting rhizobacteria in extensive wheat production in Turkey
Authors: Turan Metin , Gulluce Medine , von Wirén Nicolaus , Sahin Fikrettin
Published: November 2012

Plant growth–promoting rhizobacteria (PGPR) have been reported to stimulate the growth and yield of grain crops, particularly when nutrient supply is poor. However, the mechanisms underlying stimulation of plant growth may vary depending not only on growth conditions and crop management but also on plant and bacterial species. The present study assessed the effect of an inoculation with single or multiple PGPR strains on phosphorus (P)‐solubilization processes in the soil and on grain yield in wheat. Single inoculation with Bacillus subtilis OSU‐142, Bacillus megaterium M3, or Azospirillum brasilense Sp245 increased grain yield by 24%, 19%, and 19%, respectively, while a mixed inoculation with OSU‐142, M3, and Sp245 increased grain yield by 33% relative to noninoculated plants. Single inoculations with Paenibacillus polymyxa RC05 or Bacillus megaterium RC07 were less effective. Single or mixed treatments with OSU‐142, M3, and Sp245 increased the concentrations of the labile and moderately labile P fractions in rhizosphere soil. The growth‐stimulating effect of OSU‐142, M3, and Sp245 was also reflected by higher P concentrations in most plant organs. Among all inocula tested, the highest plant P acquisition was obtained in the presence of M3 and accompanied by the highest microbial P levels and the highest phosphatase activities in the rhizosphere soil. In conclusion, seed inoculation with mixed PGPR strains may effectively substitute for a part of P‐fertilizer application in extensive wheat production, and in particular M3 appears to improve the solubilization of inorganic soil P.
Insitu Raman spectroscopic observation of sequential hydrolysis of stannous chloride to abhurite, hydroromarchite, and romarchite
Authors: Chen Xiaoyun , Grandbois Matthew
Published: November 2012

The sensitive character of tin oxidation and the effect of pH on the solubility of tin species highlight several challenges for further understanding tin speciation within aqueous solutions. Raman spectroscopic monitoring of aqueous stannous chloride solutions over a broad pH range resulted in the observation of several insoluble tin species (e.g. abhurite and hydroromarchite) suspended within the neutral and alkaline solutions. An aqueous tin speciation mechanism was proposed based on semi‐quantitative indirect hard modeling analysis of these solutions. The methods employed in this study demonstrate the usefulness of Raman spectroscopy for the characterization of complex heterogeneous mixtures. Copyright © 2012 John Wiley & Sons, Ltd.
Theoretical investigation on surface‐enhanced Raman evidence for conformation transition of dimercaptoazobenzene adsorbed on gold nanoclusters
Authors: Lang Xiu‐Feng , Yin Peng‐Gang , Tan En‐Zhong , You Ting‐Ting , Guo Lin
Published: November 2012

Probing and controlling the configurations and mechanical motions of the azobenzenes adsorbed on the metal substrates are preliminary for their applicability in various functional devices. In this work, we presented a detailed investigation of Raman properties of the dimercaptoazobenzene (DMAB) bound to gold nanoclusters using density functional calculations. It is demonstrated that the spectral features of the trans conformation of DMAB are quite different from the cis conformation, and the Raman intensities of the trans‐DMAB are much larger. Magnitude of chemical enhancement for the adsorbed trans‐DMAB is found to be close to or less than that for the adsorbed cis‐DMAB for the molecule–cluster complexes. This change trend can be, to a large extent, governed by the energy difference between the highest occupied energy level of the molecule and the lowest unoccupied energy level of the gold. Moreover, it is further demonstrated that differences in Raman intensities of the two conformations can be amplified for the cluster–molecular–cluster junctions, and thus chemical enhancement is much larger for the trans conformation than the cis conformation, possibly facilitating the experimental identification of the trans/cis DMAB. Copyright © 2012 John Wiley & Sons, Ltd.
Changes in fatty acid profile of feta cheese including conjugated linoleic acid
Authors: Laskaridis Kostas , Serafeimidou Amalia , Zlatanos Spiros , Gylou Evgenia , Kontorepanidou Evdokia , Sagredos Angelos
Published: November 2012

Background

During the last two decades much attention has been given to conjugated linoleic acid (CLA) because of its potentially beneficial biological effects. Cheese is one of the major dietary sources of CLA. However, the CLA content of Greek cheeses is variable and affected by many factors. Fatty acid analysis of feta cheese, made of sheep's milk, was conducted at different stages of the manufacturing process in order to monitor and explain fatty acid and especially CLA changes.

Results

CLA content in fresh milk and during the early stages of manufacture was 0.66 ± 0.02 g 100 g−1 fatty acids; it increased during the ripening process (0.75 ± 0.06 g 100 g−1 fatty acids) and decreased during storage (0.52 ± 0.15 g 100 g−1 fatty acids). Saturated fatty acids (SFA), increased after 37 and 48 days of aging, while monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), showed the opposite tendency.

Conclusion

CLA content significantly increased during the ripening stages and decreased during aging (P ≤ 0.05). CLA is not stable during manufacture and storage of feta cheese, a fact which should be resolved, since this biologically active substance can be obtained from the diet.© 2012 Society of Chemical Industry
Characterization of starch phosphorylases in barley grains
Authors: Higgins Jody E , Kosar‐Hashemi Behjat , Li Zhongyi , Howitt Crispin A , Larroque Oscar , Flanagan Bernadine , Morell Matthew K , Rahman Sadequr
Published: November 2012

Background

Starch is synthesized in both leaves and storage tissues of plants. The role of starch syntheses and branching enzymes is well understood; however, the role of starch phosphorylase is not clear.

Results

A gene encoding Pho1 from barley was characterized and starch phosphorylases from both developing and germinating grain were characterized and purified. Two activities were detected: one with a molecular mass of 110 kDa and the other of 95 kDa. It was demonstrated through the use of antisera that the 110 kDa activity was located in the amyloplast and could correspond to the polypeptide encoded by the Pho1 gene cloned. The 95 kDa activity was localized to the cytoplasm, most strongly expressed in germinating grain, and was classified as a Pho2‐type sequence. Using RNAi technology to reduce the content of Pho1 in the grain to less than 30% of wild type did not lead to any visible phenotype, and no dramatic alterations in the structure of the starch were observed.

Conclusion

Two starch phosphorylase activities were identified and characterized in barley grains, and shown to be present during starch synthesis. However, their role in starch synthesis still remains to be elucidated.© 2012 Society of Chemical Industry
Ammonium as sole N source improves grain quality in wheat
Authors: Fuertes‐Mendizábal Teresa , González‐Torralba Jon , Arregui Luis M , González‐Murua Carmen , González‐Moro M Begoña , Estavillo José M
Published: November 2012

Background

The skilful handling of N fertilizer, including N source type and its timing, is necessary to obtain maximum profitability in wheat crops in terms of production and quality. Studies on grain yield and quality with ammonium as sole N source have not yet been conducted. The aim of this study was to evaluate the effect of N source management (nitrate vs. ammonium), and splitting it into two or three amendments during the wheat life cycle, on grain yield and quality under irrigated conditions.

Results

This experiment demonstrates that Cezanne wheat plants growing with ammonium as exclusive N source are able to achieve the same yield as plants growing with nitrate and that individual wheat plants grown in irrigated pots can efficiently use late N applied in GS37. Ammonium nutrition increased both types of grain reserve proteins (gliadins and glutenins) and also increased the ratio gli/glu with respect to nitrate nutrition. The splitting of the N rate enhanced the ammonium effect on grain protein composition.

Conclusions

The application of ammonium N source, especially when split into three amendments, has an analogous effect on grain protein content and composition to applications at a higher N rate, leading to higher N use efficiency. © 2012 Society of Chemical Industry
Analysis of kresoxim‐methyl and its thermolabile metabolites in Korean plum: An application of pepper leaf matrix as a protectant for GC amenable metabolites
Authors: Rahman Md. Musfiqur , Park Jong‐Hyouk , Abd El‐Aty A. M. , Choi Jeong‐Heui , Cho Soon‐Kil , Yang Angel , Park Ki Hun , Shim Jae‐Han
Published: November 2012

A new method was developed for kresoxim‐methyl (parent compound) and its two thermolabile metabolites, BF 490‐2 and BF 490‐9, in Korean plum, introducing pepper leaf matrix as a natural analyte protectant for GC‐amenable metabolites using a GC‐electron capture detector. Samples were extracted with a simple and rapid method using a mixture of ethyl acetate–n‐hexane (1:1) and salts, and purified via SPE. Due to the elution gap between parent compound and metabolites in the SPE cartridge and matrix interference, kresoxim‐methyl was isolated separately from its metabolites. An optimized amount of pepper leaf matrix (0.25 g/mL) was added to the metabolites prior to each injection. Calibration curves were linear over the concentration ranges with coefficient of determination (r2) ≥ 0.999. The method was validated in triplicate at two fortification levels, giving recoveries ranging between 74.3 and 101.4%, and RSDs less than 5%. The LOD and LOQ were 0.015 and 0.05 mg/kg, respectively. The method was successfully applied to real samples where kresoxim‐methyl residues were detected in field‐incurred plum samples. Residues were confirmed using GC‐MS.
Preliminary extraction of tannins by 1‐butyl‐3‐methylimidazole bromide and its subsequent removal from Galla chinensis extract using macroporous resins
Authors: Lu Chunxia , Luo Xiaoling , Lu Liliang , Li Hongmin , Chen Xia , Ji Yong
Published: November 2012

In recent years, ionic liquids have become increasingly attractive as ‘green solvents’ used in the extraction of bioactive compounds from natural plant. However, the separation of ionic liquid from the target compounds was difficult, due to their low vapour pressure and high stabilities. In our study, ionic liquid‐based ultrasonic and microwave‐assisted extraction was used to obtain the crude tannins, then the macroporous resin adsorption technology was further employed to purify the tannins and remove the ionic liquid from crude extract. The results showed that XDA‐6 had higher separation efficiency than other tested resins, and the equilibrium experimental data were well fitted to Langmuir isotherms. Dynamic adsorption and desorption were performed on XDA‐6 packed in glass columns to optimise the separation process. The optimum conditions as follows: the ratio of column height to diameter bed was 1:8, flow rate 1 BV/h (bed volume per hour), 85% ethanol was used as eluant while the elution volume was 2 BV. Under the optimised conditions, the adsorption and desoption rate of tannins in XDA‐6 were 94.81 and 91.63%, respectively. The content of tannins was increased from 70.24% in Galla chinensis extract to 85.12% with a recovery of 99.06%. The result of ultra‐performance liquid chromatography (UPLC)‐MS/MS analysis showed that [bmim]Br could be removed from extract.
Separation selectivity patterns of fully charged achiral compounds in capillary electrophoresis with a neutral cyclodextrin
Authors: Soonthorntantikul Wasura , Srisa‐art Monpichar , Leepipatpiboon Natchanun , Nhujak Thumnoon
Published: November 2012

Based on the separation selectivity equation, related to the dimensionless parameters for fully charged achiral analytes using a neutral CD, the separation selectivity can be classified into seven patterns. With respect to CZE without CD, the presence of CD in the buffer may improve, or reduce, the separation selectivity with this effect being accompanied by the same or reversed electrophoretic mobility order for charged analytes. This can depend on the separation selectivity of the two analytes in free solution, the binding selectivity, the separation selectivity of analyte–CD complexes and the ratio of electrophoretic mobility of the analytes in free, and complexed forms. Using positional isomers of benzoic acids and phenoxy acids as test analytes and α‐CD as a selector, the observed separation selectivity shapes were found to be in excellent agreement with the predicted separation selectivities.
Monitoring of alcohol markers by capillary electrophoresis
Authors: Caslavska Jitka , Thormann Wolfgang
Published: November 2012

Work dealing with the monitoring of alcohol markers by CE performed during the past two decades led to the development of assays for carbohydrate‐deficient transferrin (CDT), ethyl sulfate, ethyl glucuronide, and phosphatidylethanol in body fluids and first attempts for the detection of the urinary 5‐hydroxytryptophol/5‐hydroxyindoleacetic acid ratio and stable hemoglobin acetaldehyde adducts. Most notably are assays for CDT that have been commercialized and are being used in many laboratories under routine conditions. This paper provides insight into the development, specifications, and use of the currently known CE‐based assays suitable to detect alcohol markers. The achievements reached so far indicate that CE is an attractive technology for monitoring alcohol markers. This is particularly seen with the CDT assays that do not require an elaborate sample pretreatment and thus could be fully automated for high‐throughput analyses on multicapillary instruments.
Simulation of the chromatographic separation process in HPLC employing suspended‐state NMR spectroscopy – comparison of interaction behavior for monomeric and hydride‐modified C18 stationary phases
Authors: Yeman Helen , Nicholson Tim , Matyska Maria T. , Pesek Joseph J. , Albert Klaus
Published: November 2012

The interactions of different analytes with monomeric and hydride‐modified stationary phases have been investigated employing suspended‐state NMR spectroscopy. The suspended‐state high‐resolution/magic‐angle‐spinning 1H‐NMR spectrum of an analyte in the presence of C18 SP material shows a splitting into two sets of signals for the analyte molecule. One state reflects a closer interaction between analyte and C18‐modified surface that results in an upfield shift and broader signal half‐widths. This phenomenon suggests that the analyte exists in two environments. We report a systematic approach upon the investigation on the interaction in the interface of analyte, mobile phase, and modified silica through synthesis of differently modified silica with a gradual increase in surface coverage. The determination of the signal half‐widths and chemical shifts revealed a relationship between the modification technique of the C18 SPs and the chromatographic and NMR spectroscopic behavior. Increasing ligand density results in higher shielding of the NMR signals for the analyte in the “adsorbed” state. The measurement of spin‐lattice relaxation times T1 of the analyte molecule correlate NMR parameter together with separation behavior in HPLC. Furthermore, suspended‐state and solid‐state NMR measurements revealed different alkyl chain mobilities for the monomeric and hydride‐modified SPs.
Determination of crystal violet in seawater and seafood samples through off‐line molecularly imprinted SPE followed by HPLC with diode‐array detection
Authors: Lian Ziru , Wang Jiangtao
Published: November 2012

A highly selective sample cleanup procedure combined with molecularly imprinted SPE was developed for the isolation of crystal violet from seawater and seafood samples. The molecularly imprinted polymer was prepared using crystal violet as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross‐linker. The crystal violet‐imprinted polymer was used as the selective sorbent for the SPE of crystal violet. An off‐line molecularly imprinted SPE method followed by HPLC with diode‐array detection for the analysis of crystal violet was also established. Good linearity on the molecularly imprinted SPE columns was obtained from 0 to 200 μg/L (R2 > 0.99). The result demonstrated that the proposed method can be used for the direct determination of crystal violet in seawater and seafood samples. Finally, five samples were analyzed and the following crystal violet concentrations were obtained: 0.92 and 0.52 μg/L in two seawater samples, as well as 0.36 and 0.27 μg/kg in two seafood samples. There is no crystal violet detected in the third seawater sample.
Mesenchymal Stem Cells Overexpressing C-X-C Chemokine Receptor Type 4 Improve Early Liver Regeneration of Small-for-Size Liver Grafts
Authors: Du Zhiyong , Wei Cuifeng , Yan Jiqi , Han Baosan , Zhang Mingjun , Peng Chenghong , Liu Yingbin
Published: November 2012

Mesenchymal stem cell (MSC) therapy can prevent hepatic parenchymal cell loss and promote tissue repair. However, poor MSC engraftment is one of the primary barriers to the effectiveness of cell therapy because culture-expanded MSCs progressively down-regulate C-X-C chemokine receptor type 4 (CXCR4) expression and lose their ability to migrate toward a concentration gradient of stromal cell–derived factor 1a (SDF1a). In this study, we investigated whether a CXCR4-MSC infusion could protect hepatocytes and stimulate regeneration in 50% reduced size liver transplantation (RSLT). Rats that underwent 50% RSLT were randomly divided into 3 groups: a phosphate-buffered solution group (PBS), a green fluorescent protein (GFP)–MSC group, and a CXCR4-MSC group. Rats received 1 mL of PBS with or without a resuspension of GFP-MSCs or CXCR4-MSCs. The factors secreted by MSCs, the graft function, the apoptosis and proliferation of hepatocytes, the efficacy of MSC engraftment, and the expression of SDF1α, albumin (Alb), and cytokeratin 18 (CK18) in engrafted GFP-positive MSCs were assessed. A systemic infusion of GFP-MSCs led to a reduction of the release of liver injury biomarkers and apoptosis of hepatocytes; CXCR4 overexpression did not further reduce the liver injury. However, CXCR4 overexpression enhanced MSC engraftment in liver grafts, improved the effect on the proliferation of hepatocytes, and thus provided a significant 1-week survival benefit. SDF1α expression in grafts was elevated after transplanted CXCR4-MSCs were recruited to the remnant liver. However, engrafted MSCs did not express the markers of hepatocytes, including Alb and CK18, in vivo 168 hours after transplantation. CXCR4 overexpression enhanced the mobilization and engraftment of MSCs into small-for-size liver grafts, in which these cells promoted the early regeneration of the remnant liver not by direct differentiation but perhaps by a paracrine mechanism. Liver Transpl 19:215-225, 2013. © 2012 AASLD.
National survey of provider opinions on controversial characteristics of liver transplant candidates
Authors: Secunda Katharine , Gordon Elisa J. , Sohn Min W. , Shinkunas Laura A. , Kaldjian Lauris C. , Voigt Michael D. , Levitsky Josh
Published: November 2012

Candidate selection for liver transplantation presents challenging ethical issues that require balancing the principles of justice and utility. The goal of this study was to assess the opinions of US transplant providers regarding the ways in which controversial medical and psychosocial characteristics influence patient eligibility for liver transplantation. An online, anonymous survey about adult patient characteristics was sent to providers (hepatologists, surgeons, psychiatrists, and social workers) at all 102 active adult liver transplant centers in the United States. A majority of the providers (251/444 or 56.5%) completed the survey. The providers were queried about 8 characteristics, and the 3 that were ranked most controversial were incarceration, marijuana use, and psychiatric diagnoses. Most providers identified a patient age ≥ 80 years (62.7%), a body mass index ≥ 45 kg/m2 (56.6%), and current incarceration with a lifetime sentence (54.7%) as absolute contraindications to liver transplantation. In a multivariate analysis, the identification of absolute contraindications varied significantly with the provider type, the center volume, and the geographical region. Less than half of the providers reported that their centers had written policies regarding most of the characteristics examined. In conclusion, providers differ significantly in their opinions on controversial patient characteristics and transplant contraindications. Along with a paucity of literature data on outcomes, these provider differences may play a role in the fact that many centers do not have formal policies for selecting patients with these characteristics. Evidence-based data on the outcomes of such patients are needed to guide the formation of written policies to better standardize eligibility criteria. Liver Transpl 19:395–403, 2013. © 2012 AASLD.
Chemical Vapor Deposition for Solvent‐Free Polymerization at Surfaces
Authors: Yagüe Jose Luis , Coclite Anna Maria , Petruczok Christy , Gleason Karen K.
Published: November 2012

Chemical vapor deposition (CVD) methods are a powerful technology for engineering surfaces. When CVD is combined with the richness of organic chemistry, the resulting polymeric coatings, deposited without solvents, represent an enabling technology in many different fields of application. This article focuses on initiated chemical vapor deposition (iCVD), a new technique that utilizes benign reaction conditions to yield conformal and functional polymer thin films. The latest achievements in coating surfaces and 3D substrates with functional materials, and the use of the technique for biotechnology and selective permeation applications are reviewed, and future directions for iCVD technology are discussed.
A probabilistic approach to the maximal diameter theorem
Authors: Kuwada Kazumasa
Published: November 2012

Under a positive curvature and a finite dimension in terms of the Bakry‐Émery tensor on a Riemannian manifold, the Bonnet‐Myers type diameter bound and the rigidity theorem are extended. The corresponding second order generator need not be symmetrizable. The proof is based on the Laplacian comparison theorem and stochastic analysis of radial processes.
New Trends for Utilization of Rubber Wastes
Authors: Yehia A. , Abdelbary E. M. , Mull M. , Ismail M. N. , Hefny Y.
Published: November 2012

Summary: The scrape rubber is difficult to recycle, since it is not thermoplastic material. Consequently, it must be converted into a powder. The scrape rubber powder can be reused via different ways: a‐ Reclamation The reclamation process was studied. This process converts the rubber powder into elastic‐plastic materials. The obtained reclaims were introduced into NR formulations. The obtained data reveal that, 10–30% reclaimed rubber can replace virgin NR without scarifying the basic properties of the rubber vulcanizates. In such way we can gain cost reduction. b‐ Reuse as filler‐extender The rubber powder was treated with some oxidizing agents and namely HNO3 and H2O2 to modify its surface. The result of such treatment creates some functional groups such as carbonyl groups. The treated rubber powder was used as filler‐extender in NR formulations. The treated rubber powder improves the tensile strength of the vulcanizates to some extent (62%). On the other hand, the treated powder was used in combinations with the classical reinforcing carbon black (HAF). The obtained results showed that, 20–40% of HAF can be replaced by the treated powder in NR mixes. The obtained vulcanizates have good physico‐mechanical properties. In such way the production cost can be reduced. c‐ Utilization of sulfonated rubber powder as ion exchanger The rubber powder was sulfonated with Sulfuric and chlorosulfonic acids. The sulfonated product was evaluated as ion exchange resin to clear the industrial wastewater from heavy metals. The data showed that the Sodium salt form is more efficient ion exchanger than the acid form. d‐ Utilization in pavement The rubber powder is mixed with asphalt used in road pavement. The performance of asphalt concrete greatly depends on the particle size of the rubber powder used. The fine powder greatly improves the mechanical performance of the road pavement. The rubber powder was chemically modified. It was found that such modification had greatly improved the performance road pavement.
Fabrication of Bioactive Polyoxymethylene Nanocomposites for Bone Tissue Replacement
Authors: Jose Ajith James , Alagar M.
Published: November 2012

Summary: Stearic acid modified nano hydroxyapatite (n‐SHA) filled polyoxymethylene (POM) nanocomposites were prepared by melt mixing method for bone tissue replacement and regeneration applications. Contact angle measurements of POM nanocomposites were carried out to understand the effect of n‐SHA addition on the hydrophobicity of nanocomposites. The mechanical properties like tensile strength, Young's modulus and elongation at break were found to be increased significantly by the incorporation of n‐SHA into the POM matrix. The bone‐bonding ability of the nanocomposites was evaluated by examining the apatite formation on their surface after soaking in simulated body fluid (SBF) and apatite formation was studied by atomic force microscopy (AFM). The protein adhesion studies revealed the enhanced biocompatibility of the nanocomposites due to the presence of n‐SHA nanofillers on the surface and it provides favorable binding sites for protein adsorption. The significant improvement in the biocompatibility as well as mechanical, thermal and hydrophobic properties of the POM nanocomposites makes it a potential future material for bone implantation.
Cell cycle‐dependent expression of p42.3 promotes mitotic progression in malignant transformed cells
Authors: Mao Linlin , Sun Wei , Li Wenmei , Cui Jiantao , Zhang Jingyu , Xing Rui , Lu Youyong
Published: November 2012

In an earlier study, we cloned the p42.3 gene and showed that its expression was specific to tumors in a number of tumor cell lines and primary tumor tissues. However, the biological role and function of this gene remains largely unknown. In this study, p42.3 expression was found to be cell cycle‐dependent at both the mRNA and protein levels in several human tumor cell lines. Typically, abundant expression was detected at G1 and M phases compared with S and G2 phases. Expression peaked at early G1 phase then decreased drastically at late G1, S, and G2. Furthermore, transfection of the p42.3 gene into NIH3T3 cells promoted malignant transformation, accompanied by accelerated mitotic progression and altered chromosome segregation. It was also observed that Cyclin B1 was upregulated and Cdc2‐Tyr15 was downregulated following p42.3 overexpression in NIH3T3 cells. Combined, these results indicate that p42.3 as a cell cycle‐regulated gene contributes to promoting cell cycle progression through disruption of mitotic regulation, and may play important roles in malignant transformation. © 2012 Wiley Periodicals, Inc.
Evolution of PLS for Modeling SAR and omics Data
Authors: Hasegawa Kiyoshi , Funatsu Kimito
Published: November 2012

In quantitative structure‐activity relationship (QSAR), multivariate statistical methods are commonly used for data analysis. Partial least squares (PLS) is of particular interest because it can analyze data with strongly collinear, noisy and numerous X variables, and also simultaneously models several activity variables Y. PLS provides several prediction regions and diagnostic plots as statistical measures. PLS has evolved for coping with the severe demands imposed by complex data structures. In this review article, we outline the algorithms of five advanced PLS techniques and provide some representative examples of each. The selected models are Nonlinear PLS, Multiway PLS, Hierarchical PLS, Orthogonal PLS, and Bi‐modal PLS. Studies of particular aspects of living cells (such as the set of genes or proteins in the cell and their interactions) are collectively known as the ‐omics fields. Omics integrate heterogeneous scientific disciplines and include chemogenomics, proteomics, and metabolomics. The datasets produced within the omics fields are numerous, megavariate and extremely complex. The data structures are frequently incomplete, noisy, nonlinear and collinear demanding modern and powerful multivariate data analysis methods. In particular, the omics technologies have steered biology towards the adoption of orthogonal PLS. We also describe future prospects for the use of PLS algorithms in the omics fields.
Inversion recovery at 7 T in the human myocardium: Measurement of T1, inversion efficiency and B1+
Authors: Rodgers Christopher T. , Piechnik Stefan K. , DelaBarre Lance J. , Van de Moortele Pierre‐François , Snyder Carl J. , Neubauer Stefan , Robson Matthew D. , Vaughan J. Thomas
Published: November 2012

At clinical MRI field strengths (1.5 and 3 T), quantitative maps of the longitudinal relaxation time T1 of the myocardium reveal diseased tissue without requiring contrast agents. Cardiac T1 maps can be measured by Look‐Locker inversion recovery sequences such as ShMOLLI at 1.5 and 3 T. Cardiovascular MRI at a field strength of 7 T has recently become feasible, but doubts have remained as to whether magnetization inversion is possible in the heart due to subject heating and technical limitations. This work extends the repertoire of 7 T cardiovascular MRI by implementing an adiabatic inversion pulse optimized for use in the heart at 7 T. A “ShMOLLI+IE” adaptation of the ShMOLLI pulse sequence has been introduced together with new postprocessing that accounts for the possibility of incomplete magnetization inversion. These methods were validated in phantoms and then used in a study of six healthy volunteers to determine the degree of magnetization inversion and the T1 of normal myocardium at 7 T within a 22‐heartbeat breathhold. Using a scanner with 16 × 1 kW radiofrequency outputs, inversion efficiencies ranging from −0.79 to −0.83 (intrasegment means; perfect 180° would give −1) were attainable across the myocardium. The myocardial T1 was 1925 ± 48 ms (mean ± standard deviation). Magn Reson Med, 70:1038–1046, 2013. © 2012 Wiley Periodicals, Inc.
Researching children's health experiences: The place for participatory, child‐centered, arts‐based approaches
Authors: Carter Bernie , Ford Karen
Published: November 2012

A central concern when conducting qualitative health research with children is eliciting data that genuinely reflect their perspectives. Invariably, this involves being child‐centered and participatory. Drawing and photography increasingly accompany dialogic methods to facilitate children's communication through arts‐based and verbal modes of expression. However, little literature is available on how arts‐based tools shape data. We suggest that researchers need to be attentive to how such tools can liberate, constrain and frame data generated by children, drawing attention to the promises of such approaches as well as the conundrums that can arise from their use. We explore the place for participatory, child‐centered, arts‐based approaches using examples of the use of drawing and photography in our own studies. © 2012 Wiley Periodicals, Inc. Res Nurs Health 36:95–107, 2013
Assembly of a cohort of children treated for acute myeloid leukemia at free‐standing children's hospitals in the United States using an administrative database
Authors: Kavcic Marko , Fisher Brian T. , Torp Kari , Li Yimei , Huang Yuan‐Shung , Seif Alix E. , Vujkovic Marijana , Aplenc Richard
Published: November 2012

Pediatric Health Information System data were used to establish a multi‐center cohort of 1,686 children treated for newly diagnosed acute myeloid leukemia (AML). The cohort assembly process, which included myeloid leukemia ICD‐9 discharge diagnosis codes and manual review of induction chemotherapy, was validated by chart review at a single institution. The use of ICD‐9 codes alone resulted in a poor positive predictive value (PPV; 31%). Inclusion of the results from the chemotherapy review improved the PPV to 100% without compromising sensitivity (95.7%). This cohort provides a reliable source for future comparative effectiveness and clinical epidemiology studies in pediatric AML. Pediatr Blood Cancer 2013; 60: 508–511. © 2012 Wiley Periodicals, Inc.
Association of midtrimester short femur and short humerus with fetal growth restriction
Authors: de Carvalho Ana Alice Vidal , Carvalho José Antônio , Figueiredo Israel , Velarde Luis Guillermo Coca , Marchiori Edson
Published: November 2012

Objective

To investigate the association between the midtrimester presence of short femur and short humerus and intrauterine growth restriction.

Methods

This retrospective study included ultrasound examinations of 1043 fetuses. Fetuses with normal‐length bones were compared with fetuses that had femoral or humeral lengths below the 5th percentile for gestational age by Student's t‐test and the chi‐squared test. The association between short bones and fetal growth restriction development was evaluated by Fisher's exact test. Fetuses with estimated weight below the 10th percentile for gestational age and abnormal umbilical artery flow were considered to have growth restriction.

Results

Femoral and humeral lengths were normal in 974 (93.4%) fetuses; 19 (1.8%) fetuses had short femora, 65 (6.2%) had short humeri, and 15 (1.4%) had short femora and humeri combined. Of fetuses included in the analysis, 603 (57.8%) underwent Doppler examination. Short femur [odds ratio = 9.7, 95% confidence interval = 1.9–50.2, P = 0.03] and short humerus (odds ratio = 13, 95% confidence interval = 4.9–34.6, P < 0.001) were associated with fetal growth restriction.

Conclusion

Fetuses with midtrimester short femur, short humerus, or short femur and humerus combined require more intensive surveillance for growth restriction development. © 2012 John Wiley & Sons, Ltd.
Synthesis, structure, and thermal stability of poly(methyl methacrylate)‐co‐ poly(3‐tri(methoxysilyil)propyl methacrylate)/ montmorillonite nanocomposites
Authors: Carvalho Hudson W.P. , Suzana Ana F. , Santilli Celso V. , Pulcinelli Sandra H.
Published: November 2012

The structure and the thermodegradation behavior of both poly(methyl methacrylate)‐co‐poly(3‐tri(methoxysilyil)propyl methacrylate) polymer modified with silyl groups and of intercalated poly(methyl methacrylate)‐co‐poly(3‐tri(methoxysilyil)propyl methacrylate)/Cloisite 15A™ nanocomposite have been in situ probed. The structural feature were comparatively studied by Fourier transform infrared spectroscopy (FTIR), 13C and 29Si nuclear magnetic resonance (NMR), and small angle X‐ray scattering (SAXS) measurements. The intercalation of polymer in the interlayer galleries was evidenced by the increment of the basal distance from 31 to 45 Å. The variation of this interlayer distance as function of temperature was followed by in situ SAXS. Pristine polymer decomposition pathway depends on the atmosphere, presenting two steps under air and three under N2. The nanocomposites are more stable than polymer, and this thermal improvement is proportional to the clay loading. The experimental results indicate that clay nanoparticles play several different roles in polymer stabilization, among them, diffusion barrier, charring, and suppression of degradation steps by chemical reactions between polymer and clay. Charring is atmosphere dependent, occurring more pronounced under air. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Origin of dielectric response and conductivity of some alicyclic polyimides
Authors: Ioan Silvia , Hulubei Camelia , Popovici Dumitru , Musteata Valentina Elena
Published: November 2012

High‐performance alicyclic‐containing polyimides for advanced applications, derived from 5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic acid anhydride or bicyclo[2.2.2]oct‐7‐ene‐2,3,5,6‐ tetracarboxylic dianhydride and two flexible aromatic diamines, were synthesized by a classical two‐step polycondensation reaction. The dielectric spectra behavior over wide frequency and temperature ranges of 1 Hz‐1 MHz and –150°C÷+250°C, respectively, was investigated according to chemical and micro‐structural aspects. The dielectric constants have low values and are dependent on dianhydride flexibility and diamine links, in relation with the charge–transfer complex (CTC) and free volume, and, consequently, with packing of the polymer chains and polarizable groups per volume units. All polyimide films develop two relaxation processes, i.e., γ and β relaxation, involving different enthalpy and entropy contributions induced by their chemical structures. Frequency–temperature‐dependent conductivity showed that conductivity increased with frequency and also that energy bandgap representation could be suitable for explaining the temperature influence on AC‐conductivity. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Characterization of morphology and gas separation performance of dry‐cast polycarbonate membranes
Authors: Fu Ywu‐Jang , Chen Jung‐Tsai , Chen Chun‐Chieh , Liao Kuo‐Sung , Hu Chien‐Chieh , Lee Kueir‐Rarn , Lai Juin‐Yih
Published: November 2012

The development of the morphology and microstructure in dry‐cast membranes from polycarbonate (PC)/dichloromethane (DCM) and PC/tetrahydrofuran (THF) solutions was investigated in this work. It was shown that changing the relative humidity (RH) of the air altered the transparency and the surface morphology of the membranes. Positron lifetime spectra for membranes with different surface morphology gave similar free volume parameters, which are believed to be mainly responsible for the constant selectivity of the membranes. In this study, the permeation and adsorption properties of the PC membranes cast from PC/DCM and PC/THF solutions were characterized as a function of the RH. Results demonstrated that the permeability of membranes increased with increasing RH of the air. The change in the permeability is presumably related to the forming of pores on the membrane surface due to the vapor‐induced phase separation during casting. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers