bluuebunny/crossref_metadata_2025 huggingface dataset:
Casein and transglutaminase‐mediated modification of wool surface
Authors: Cui Li , Fan Xuerong , Wang Ping , Wang Qiang , Fu Guangtong
Published: February 2011

In this study, casein, a protein found in milk, was used as a surface‐coating material for improving wool fabric properties mediated by a microbial protein cross‐linking enzyme: transglutaminase (TGase). For the wool fabric used in this study, 4% casein (owf) treatment for 1 h combined with 20 U/g fabric of microbial TGase reduced the area shrinkage of the KMnO4‐pretreated wool fabric from 11.32±0.26 to 4.57±0.15%. The tensile strength increased from 275±5.0 to 315±2.1 N. The casein cross‐linked by TGase on wool exhibited better stability than that with the inactivated enzyme in warm water, Na2CO3 and SDS solutions. Scanning electron micrographs demonstrated that the casein and TGase treatment smoothened the wool fiber surface by coating or filling the raised scales of the wool.
Metabolic precursors enhance the production of poly‐ε‐lysine by Streptomyces noursei NRRL 5126
Authors: Bankar Sandip B. , Singhal Rekha S.
Published: February 2011

Poly‐ε‐lysine produced by streptomyces species is a promising biopolymer owing to its antimicrobial activity and safety for humans. A number of nutritional factors influencing poly‐ε‐lysine production by Streptomyces noursei NRRL 5126 were studied. Various metabolic precursors such as amino acids, tricarboxylic acid cycle intermediates and cofactors were investigated for improved production of poly‐ε‐lysine. Results indicated L‐aspartate (2 mM) and citric acid (5 mM) to substantially increase the poly‐ε‐lysine production from 97.08 to 409.94 mg/L. Addition of citric acid after 24 h and L‐aspartate after 36 h of fermentation medium further enhanced poly‐ε‐lysine production to 497.67 mg/L after a total fermentation time of 108 h. However, the use of cofactors of enzymes involved in the biosynthesis of poly‐ε‐lysine inhibited its production which is believed to be due to diversion of the flux to other metabolites.
Hyaluronic acid nanofiber wound dressing—production, characterization, and in vivo behavior
Authors: Uppal Rohit , Ramaswamy Gita N. , Arnold C. , Goodband Robert , Wang Y.
Published: February 2011

Hyaluronic acid (HA) was electrospun. The effects of flow rate, spin length, and the applied voltage on the diameter of the HA nanofibers were analyzed. The average thickness of the webs was 0.041 cm. The air permeability of sterilized HA nanofiber wound dressing was much higher than that of gauze with Vaseline. The degree of crystallinity of HA nanofibers was characterized using powder X‐ray technique and was found to be 20.6%. A preclinical study was conducted to compare healing of wounds covered by an adhesive bandage, a sterilized solid HA, gauze with Vaseline, an antibiotic dressing, and a sterilized HA nanofiber wound dressing. Results of the two methods of appraisal showed that the sterilized HA nanofiber wound dressing was the best type of dressing out of the five types of dressings compared. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Silver/hydroxyapatite composite coatings on porous titanium surfaces by sol‐gel method
Authors: Qu Jie , Lu Xiong , Li Dan , Ding Yonghui , Leng Yang , Weng Jie , Qu Shuxin , Feng Bo , Watari Fumio
Published: February 2011

Hydroxyapatite (HA) coatings loaded with nanosilver particles is an attractive method to impart the HA coating with antibacterial properties. Producing Ag/HA coatings on porous Ti substrates have been an arduous job since commonly used line‐of‐sight techniques are not able to deposit uniform coatings on the inner pore surfaces of the porous Ti. In this study, porous Ti scaffolds with high porosity and interconnected structures were prepared by polymer impregnating method. A sol‐gel process was used to produce uniform Ag/HA composite coatings on the surfaces of porous Ti substrates. Ca(NO3)2·4H2O and P2O5in an ethyl alcohol based system was selected to prepare the sol, which ensured the homogeneous distribution of Ag in the sol. The characterization revealed that silver particles uniformly distributed in the coatings without agglomeration. High antibacterial ratio (>95%), againstE. coliandS. albuswas expressed by the silver‐containing coatings (Ag/HA 0.8 and 1.6 wt %). The biocompatibility of the Ag/HA 0.8 surfaces was as good as that of pure HA surface, as revealed by culturing osteoblasts on them. The results indicated that Ag/HA 0.8 had the good balance between the biocompatibility and antibacterial properties of the coatings. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Development of a biodegradable tissue adhesive based on functionalized 1,2‐ethylene glycol bis(dilactic acid). II.
Authors: Rohm Henning W. , Lurtz Claudia , Wegmann Juergen , Odermatt Erich K. , Behrend Detlef , Schmitz Klaus‐Peter , Sternberg Katrin
Published: February 2011

In body regions where damage and bleeding must be avoided, a substitute for mechanical tissue fixation by sutures or staplers is needed. Since tissue adhesives provide easy and fast handling they are a promising alternative. The present study reports the development and analysis of a tissue adhesive that consists of two adhesive components: hexamethylene diisocyanate (HDI) functionalized 1,2‐ethylene glycol bis(dilactic acid) (ELA‐NCO) and chitosan chloride. This composition was chosen based on preliminary studies on several chain elongation agents. The present study evaluates this adhesive system by IR‐spectroscopy, tensile tests, and gel point measurements in comparison to fibrin glue. The system's in vitro biocompatibility was tested with mouse fibroblasts (L929) according to ISO 10993‐5. Furthermore, an implantation study was performed in SPF‐Wistar rats. The adhesive strength of manually applied mixtures or mixtures applied by double chamber syringes with a mixing extruder was determined to be significantly higher than that of fibrin glue on bovine muscle tissue at 37°C. Tensile strength increased further when exposure time of the adhesive was increased from 10 min to 48 h. The rheological gel point determination showed that the mixture of ELA‐NCO/DMSO and chitosan chloride offers a time window large enough to readjust the fused joint during surgery, as opposed to fibrin glue. Additionally, the in vitro and in vivo biocompatibility studies of the adhesive system revealed no toxic effects on the surrounding tissue. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Telomerase-deficient mice exhibit bone loss owing to defects in osteoblasts and increased osteoclastogenesis by inflammatory microenvironment
Authors: Saeed Hamid , Abdallah Basem M , Ditzel Nicholas , Catala-Lehnen Philip , Qiu Weimin , Amling Michael , Kassem Moustapha
Published: February 2011

Telomere shortening owing to telomerase deficiency leads to accelerated senescence of human skeletal (mesenchymal) stem cells (MSCs) in vitro, whereas overexpression leads to telomere elongation, extended life span, and enhanced bone formation. To study the role of telomere shortening in vivo, we studied the phenotype of telomerase-deficient mice (Terc−/−). Terc−/− mice exhibited accelerated age-related bone loss starting at 3 months of age and during 12 months of follow-up revealed by dual-energy X-ray absorptiometric (DXA) scanning and by micro–computed tomography (µCT). Bone histomorphometry revealed decreased mineralized surface and bone-formation rate as well as increased osteoclast number and size in Terc−/− mice. Also, serum total deoxypyridinoline (tDPD) was increased in Terc−/− mice. MSCs and osteoprogenitors isolated from Terc−/− mice exhibited intrinsic defects with reduced proliferating cell number and impaired osteogenic differentiation capacity. In addition, the Terc−/−-MSC cultures accumulated a larger proportion of senescent β-galactosidase+ cells and cells exhibiting DNA damage. Microarray analysis of Terc−/− bone revealed significant overexpression of a large number of proinflammatory genes involved in osteoclast (OC) differentiation. Consistently, serum obtained from Terc−/− mice enhanced OC formation of wild-type bone marrow cultures. Our data demonstrate two mechanisms for age-related bone loss caused by telomerase deficiency: intrinsic osteoblastic defects and creation of a proinflammatory osteoclast-activating microenvironment. Thus telomerization of MSCs may provide a novel approach for abolishing age-related bone loss. © 2011 American Society for Bone and Mineral Research.
Exposure to community violence among Arab youth in Israel: rates and characteristics
Authors: Haj‐Yahia Muhammad M. , Leshem Becky , Guterman Neil
Published: February 2011

The research explored the rates and characteristics of exposure to community violence (CV) and its relevance to several sociodemographic factors among a sample of 833 Arab youth aged 14–18 years residing in diverse residential areas in Israel. Data were collected using a self‐report questionnaire. The frequency of exposure to CV during the past 12 months correlated significantly with the children's gender. The frequency of witnessing CV during that period was higher than the frequency of personally experiencing CV, and exposure to mild CV incidents during that period was higher than the frequency of exposure to severe CV incidents during the same period, with no significant relationship to sociodemographic factors. Participants reported higher rates of exposure to most CV incidents outside of the neighborhood; however, exposure to beating was higher inside the participants' neighborhood. Moreover, the highest overall rate of exposure to CV was at school. © 2011 Wiley Periodicals, Inc.
Social class as moderator of the relationship between (dis)empowering processes and psychological empowerment
Authors: Christens Brian D. , Speer Paul W. , Peterson N. Andrew
Published: February 2011

This study examined whether social class moderated the relationship between empowering and disempowering processes and psychological empowerment (PE) in a sample of individuals from five community organizing initiatives (N=490). Hierarchical regression analyses were used to test the relationship between community participation (CP) and alienation on the intrapersonal and interactional components of PE. For the intrapersonal component of PE, CP and alienation were, respectively, positive and negatively predictive. Social class was positively related to the intrapersonal component of PE, and no interaction effects were detected. For the interactional component of PE, CP was not a significant predictor, and alienation was a significant positive predictor. Social class was a negative predictor, and interaction effects between independent variables were detected. These paradoxical relationships between social class and the components of PE are pertinent to empowerment theory and measurement. Implications for social policy, community interventions, and evaluation are explored. © 2011 Wiley Periodicals, Inc.
Human salivary gland acinar cells spontaneously form three‐dimensional structures and change the protein expression patterns
Authors: Chan Yen‐Hui , Huang Tsung‐Wei , Young Tai‐Horng , Lou Pei‐Jen
Published: February 2011

Applying tissue engineering principles to design an auto‐secretory device is a potential solution for patients suffering loss of salivary gland function. However, the largest challenge in implementing this solution is the primary culture of human salivary gland cells, because the cells are highly differentiated and difficult to expand in vitro. This situation leads to the lack of reports on the in vitro cell biology and physiology of human salivary gland cells. This study used a low‐calcium culture system to selectively cultivate human parotid gland acinar (PGAC) cells from tissues with high purity in cell composition. This condition enables PGAC cells to continuously proliferate and retain the phenotypes of epithelial acinar cells to express secreting products (α‐amylase) and function‐related proteins (aquaporin‐3, aquaporin‐5, and ZO‐1). Notably, when the cells reached confluence, three‐dimensional (3D) cell aggregates were observed in crowded regions. These self‐formed cell spheres were termed post‐confluence structures (PCSs). Unexpectedly, despite being cultured in the same media, cells in PCSs exhibited higher expression levels and different expression patterns of function‐related proteins compared to the two‐dimensional (2D) cells. Translocation of aquoporin‐3 from cytosolic to alongside the cell boundaries, and of ZO‐1 molecules to the boundary of the PCSs were also observed. These observations suggest that when PGAC cells cultured on the 2D substrate would form PCSs without the help of 3D scaffolds and retain certain differentiation and polarity. This phenomenon implies that it is possible to introduce 2D substrates instead of 3D scaffolds into artificial salivary gland tissue engineering. J. Cell. Physiol. 226: 3076–3085, 2011. © 2011 Wiley‐Liss, Inc.
Chondrogenesis of the limbs and mesopodial ossification of Podocnemis expansa Schweigger, 1812 (Testudines: Podocnemidae)
Authors: Vieira Lucélia Gonçalves , Santos André L.Q. , Lima Fabiano Campos , Moura Lea Resende
Published: February 2011

We address the chondrogenic formation of the limbs and the mesopodial ossification pattern of the Pleurodira Podocnemis expansa, to resolve the homology of these elements as well as the pattern of connection of the autopodial elements and the origin of the digital arch. Embryos and juveniles of P. expansa were cleared and stained for cartilage and bone. The fore‐ and hind‐limbs were also studied histologically. We describe the development of the stylopodium and zeugopodium originating from a Y‐shaped cartilaginous condensation, and the differentiation of the primary axis and the digital arch in the initial stages of limb development. The most pronounced changes were observed in the chondrogenic pattern and ossification of the mesopodium, although development of the digits is similar and we found no ontogenetic reduction such as that described for other Testudines. In this study, as in previous research involving several groups of reptilian sauropsids, we found an inconsistent pattern between the chondrogenic formation and mesopodial ossification of the limbs, indicating that these developmental events are dissociated. In summary, the chondrogenic and ossification sequences of these elements do not follow the same pattern. In addition, the differences found between P. expansa and other species to which it was compared clearly indicate that these events follow more than one pattern in Testudines. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
Angioarchitecture of the bovine spermatic cord
Authors: Polguj Michał , Jȩdrzejewski Kazimierz S. , Topol Mirosław
Published: February 2011

We described the topography and morphometry of the testicular artery, pampiniform plexus veins, and indirect connections between them in the spermatic cord of the bull. Sixty microcorrosive casts of bovine spermatic cords were analyzed macroscopically, by stereomicroscopy, and by scanning electron microscopy. The average size of the testicles was 94.6 × 49.7 × 54.7 mm. The testicular artery formed a superiorly pointed cone‐like structure with its base fixed to the proximal part of the gonad. The artery gave off one or two branches to the head of epididymis and to the deferens duct. The pampiniform plexus originated from intra‐tunical veins. Veins of the pampiniform plexus were of smaller diameter but larger number than intra‐tunical ones. The density of the veins of the pampiniform plexus was 9.37 ± 1.07 mm−2. The testicular vein began 90–121 mm above the superior pole of the testis. In 2.9% of specimens, the testicular vein was doubled. Numerous anastomoses among veins of pampiniform plexus were observed. Additionally, indirect anastomoses between the testicular artery and pampiniform plexus veins formed by the capillary network of the vasa vasorum of the testicular artery were visualized by scanning electron microscopy. In all cases, narrowings in the casts of the precapillary vessel were observed. We also documented the vasa vasorum of the testicular artery in bulls. The density of these vessels was 22.87 ± 11.48 mm−2. The indirect arteriovenous connections together with the presence of circular constrictions of the lumen in precapillary vessels may play a role in testicular blood flow regulation. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
Neurotoxic properties of the anabolic androgenic steroids nandrolone and methandrostenolone in primary neuronal cultures
Authors: Caraci Filippo , Pistarà V. , Corsaro A. , Tomasello Flora , Giuffrida Maria Laura , Sortino Maria Angela , Nicoletti Ferdinando , Copani Agata
Published: February 2011

Anabolic‐androgenic steroid (AAS) abuse is associated with multiple neurobehavioral disturbances. The sites of action and the neurobiological sequels of AAS abuse are unclear at present. We investigated whether two different AASs, nandrolone and methandrostenolone, could affect neuronal survival in culture. The endogenous androgenic steroid testosterone was used for comparison. Both testosterone and nandrolone were neurotoxic at micromolar concentrations, and their effects were prevented by blockade of androgen receptors (ARs) with flutamide. Neuronal toxicity developed only over a 48‐hr exposure to the steroids. The cell‐impermeable analogues testosterone‐BSA and nandrolone‐BSA, which preferentially target membrane‐associated ARs, were also neurotoxic in a time‐dependent and flutamide‐sensitive manner. Testosterone‐BSA and nandrolone‐BSA were more potent than their parent compounds, suggesting that membrane‐associated ARs were the relevant sites for the neurotoxic actions of the steroids. Unlike testosterone and nandrolone, toxicity by methandrostenolone and methandrostenolone‐BSA was insensitive to flutamide, but it was prevented by the glucocorticoid receptor (GR) antagonist RU‐486. Methandrostenolone‐BSA was more potent than the parent compound, suggesting that its toxicity relied on the preferential activation of putative membrane‐associated GRs. Consistently with the evidence that membrane‐associated GRs can mediate rapid effects, a brief challenge with methandrostenolone‐BSA was able to promote neuronal toxicity. Activation of putative membrane steroid receptors by nontoxic (nanomolar) concentrations of either nandrolone‐BSA or methandrostenolone‐BSA became sufficient to increase neuronal susceptibility to the apoptotic stimulus provided by β‐amyloid (the main culprit of AD). We speculate that AAS abuse might facilitate the onset or progression of neurodegenerative diseases not usually linked to drug abuse. © 2011 Wiley‐Liss, Inc.
Involvement of interleukin‐1 in lipopolysaccaride‐induced microglial activation and learning and memory deficits
Authors: Tanaka S. , Kondo H. , Kanda K. , Ashino T. , Nakamachi T. , Sekikawa K. , Iwakura Y. , Shioda S. , Numazawa S. , Yoshida T.
Published: February 2011

We have developed an animal model of learning and memory impairment associated with activation of microglia in the mouse brain. Injection of lipopolysaccharide into the CA1 region of the mouse hippocampus resulted in an increased production of inflammatory cytokines, such as interleukin‐1β. Immunostaining for interleukin‐1β revealed an increase in the signal at 6 hr after lipopolysaccharide injection. Immunopositive cells for interleukin‐1β were colocalized with those immunopositive for CD11b. When subacute lipopolysaccharide treatment (20 μg/2 μl/injection, bilaterally for 5 consecutive days) was performed, long‐term activation of microglia and learning and memory deficits as evaluated using a step‐through passive avoidance test were observed in the wild‐type mice. Gene expression of the N‐methyl‐D‐aspartate receptor NR1 and NR2A subunits was also decreased by the lipopolysaccharide treatment. In contrast, activation of microglia and the associated behavioral deficits were not observed in mice lacking interleukin‐1α and ‐1β following the subacute lipopolysaccharide treatment, together with little change in the gene expression of NR1 and NR2A subunits. However, the subacute lipopolysaccharide treatment produced almost similar changes in those parameters in the tumor necrosis factor‐α knockout mice as in the wild‐type animals. The injection of interleukin‐1β neutralizing antibody with lipopolysaccharide for 5 consecutive days resulted in the improvement of lipopolysaccharide‐induced learning and memory deficits. These findings suggest that the expression of interleukin‐1 plays an important role in lipopolysaccharide‐induced activation of microglia and the associated functional deficits in learning and memory. © 2011 Wiley‐Liss, Inc.
Differential effects of the HESR/HEY transcription factor family on dopamine transporter reporter gene expression via variable number of tandem repeats
Authors: Kanno Kouta , Ishiura Shoichi
Published: February 2011

The 3′‐untranslated region (UTR) of the human dopamine transporter (DAT1) gene contains a variable number of tandem repeats (VNTR) domain, which is thought to be associated with dopamine‐related psychiatric disorders, personality, and behavior. However, the molecular and neuronal functions of polymorphisms within the VNTR domain are unknown. We previously identified the transcription factor HESR1 (HEY1) as a VNTR‐binding protein. Hesr1 knockout mice exhibit DAT up‐regulation in the brain and low levels of spontaneous activity. Other members of the HESR (HEY) family, including HESR2 (HEY2) and 3 (HEYL), have similar DNA‐binding domains. In this study, we analyzed the effects of HESR1, ‐2, and ‐3 on DAT1 expression in human neuroblastoma SH‐SY5Y cells using luciferase reporter assays. We found that the VNTR domain played an inhibitory role in DAT1 reporter gene expression and that HESR1 and ‐2 inhibited expression via both the core promoter and the VNTR. The inhibitory effects of HESR family members on DAT reporter gene expression differed depending on the number of repeats in the VNTR domain. We also found that each Hesr was expressed in the dopaminergic neurons in the mouse midbrain. These results suggest that the HESR family is involved in DAT expression via the VNTR domain. © 2011 Wiley‐Liss, Inc.
Global network initiative: An ethical compass for information and communications firms in the internet age
Authors: Hope Dunstan
Published: February 2011

With the explosive growth of communications technologies, organizations are facing new ethical challenges in using, gathering, storing, and sharing information that can cast them in a negative light and lead to restrictions on how they conduct business. As Yahoo!, Microsoft, and Google discovered, developing agreed‐upon principles and guidelines to direct behavior, co‐drafted by a range of stakeholders, is a practical step toward maintaining the public's trust while preserving organizational business models and protecting human rights. Moreover, their experience with the Global Network Initiative offers practical lessons on how to effectively forge multistakeholder collaboration to address complex policy. © 2011 Wiley Periodicals, Inc.
Taking a fast‐cycle approach to align organizational culture with business plans
Authors: Recardo Ronald J.
Published: February 2011

Studies show that organizations that closely align their culture in support of their business strategy outperform their competitors in both the short and long term. As this organization's experience illustrates, companies of all sizes can tap into their existing technology, organization, and process architecture to effect long‐lasting change in less than 50 percent of the time of other programs. To do so, they need to analyze their strategic direction and identify the gaps between their actual and desired cultural characteristics, values, and behaviors. © 2011 Wiley Periodicals, Inc.
Comprehensive two‐dimensional liquid chromatography with evaporative light‐scattering detection for the analysis of triacylglycerols in Borago officinalis
Authors: Mondello Luigi , Beccaria Marco , Donato Paola , Cacciola Francesco , Dugo Giovanni , Dugo Paola
Published: February 2011

An optimized 2‐D liquid chromatography (LC×LC) set‐up, based on the different selectivities of a silver ion (Ag) and a non‐aqueous reversed phase (NARP), employed in the first (D1) and the second dimension (D2), respectively, in combination with evaporative light‐scattering detection (ELSD), has been developed for the analysis of the triacylglycerol (TAG) fraction in a Borago officinalis oil. The 2‐D set‐up, thanks to the complementary separation selectivity provided by the two columns, allowed to distribute 78 TAGs throughout the 2‐D LC retention plane otherwise unachievable by 1‐D LC.
Phototherapy for chronic rhinosinusitis
Authors: Krespi Yosef P. , Kizhner Victor
Published: February 2011

Objectives

Near‐infrared laser illumination (NILI), with or without photo‐activated (PA) agents, has bactericidal and wound healing promoting effects. NILI may have a potential role managing chronic rhinosinusitis (CRS).

Methods

A prospective randomized study with 23 symptomatic post‐surgical CRS patients with positive cultures was conducted. Two groups (GR1 and GR2) were treated with NILI. Objective nasal endoscopic scoring (NES) was elaborated. GR1 was treated with a 940 nm laser, while GR2 was treated with a topical PA agent, indocyanine‐green, followed with 810 nm laser. SNOT20 scores, NES, and cultures were obtained prior to illumination. Saccharin test was performed 1 week following treatment.

Results

Some cultures remained positive through treatment, with Staph. aureus predominating. Both therapy arms demonstrated clinical efficacy. The SNOT20 score change was 0.9, 0.8 for GR1 and GR2, respectively (P < 0.05). Improvement (P < 0.05) was observed based on NES. No significant difference was observed between two treatment groups. All passed the saccharin test. Therapeutic effect was sustained for a minimum of 2 months. Side effects were minimal.

Conclusions

NILI was objectively and subjectively beneficial in managing CRS, safe, reproducible, sustained and appeared not to interfere with ciliary motility. CRS exacerbation was avoided without using antibiotics or steroids. Lasers Surg. Med. 43:187–191, 2011. © 2011 Wiley‐Liss, Inc.
Measurements of fluorine depth‐profiles on TiAl turbine blades using ion beam analytical techniques
Authors: Neve S. , Masset P. J. , Zschau H.‐E. , Schütze M.
Published: February 2011

Intermetallic TiAl alloys are foreseen to substitute Ni‐based alloys in several high‐temperature applications such as turbine blades for aeronautics. Because of their low density the mass of these components could be reduced by half. However, a mixed oxide scale of TiO2 and Al2O3 which provides no oxidation protection is growing at temperatures above 700 °C. By means of the halogen‐effect the high‐temperature oxidation resistance of TiAl alloys can be improved by orders of magnitude. Therefore fluorine was introduced into turbine blades using two different chemical fluorination methods. The application of a fluorine treatment promotes the growth of a pure and dense alumina scale which prevents the alloy from increased oxidation. In previous work it has been shown that an appropriate fluorine content after oxidation and its location beneath the surface are indicators of a successful fluorine effect. In the present work, the fluorine content was measured before and after oxidation of TNB alloy as a function of depth by using proton induced gamma‐ray emission (PIGE) in a specially designed vacuum chamber at the 2.5 MV van‐de‐Graaff accelerator at the IKF. Additionally, composition and thickness of the oxide scale was determined by Rutherford backscattering spectrometry (RBS). The ion beam techniques are non‐destructive and thus offer a method for quality assurance of the halogen treatment.
The effect of Ca on corrosion behavior of heat‐treated Mg–Al–Zn alloy
Authors: Wang Y.‐Q. , Li M.‐Z. , Li C. , Li X.‐Y. , Fan L.‐Q. , Jia T.
Published: February 2011

The effect of 0.5, 1.0, and 1.5 wt% Ca additions on the microstructure and corrosion resistance of the heat‐treated Mg–Al–Zn alloy was investigated. Addition of 0.5 wt% Ca did not form any new phase but suppressed the discontinuous precipitation of the β‐Mg17Al12 phase by being dissolved in both the second phase and magnesium matrix. In the materials containing higher amounts of Ca, however, metallographic investigation shows that Ca added to Mg–Al–Zn can obviously decrease the size of β‐Mg17Al12 and forms Al4Ca intermetallic compounds in the shape of bone‐like morphology. The corrosion tests used include constant immersion technique, and potentiodynamic polarization experiments and salt spray test. Surface examination and analytical studies were carried out using optical and scanning electron microscopy, EDX, and XRD. The results of corrosion tests show that magnesium alloy Mg–Al–Zn with 1.0 wt% Ca addition has the best corrosion resistance behavior.
Study of overheating effects in SiGe‐based p‐type heterostructures: Methods of the hole temperature determination
Authors: Berkutov I. B. , Andrievskii V. V. , Komnik Y. F. , Mironov O. A.
Published: February 2011

The effect of charge carrier overheating is studied in the p‐type Si/Si0.87Ge0.13/Si heterostructure. The hole temperature Th can be calculated using three different methods: From a comparison of the changes in the amplitude of the Shubnikov‐de Haas oscillations under the influences of temperature and current, from a comparison of the change of phase relaxation time in the weak localization effect obtained at different temperatures and minimum current and at a given temperature but at different values of current, and from a comparison of the temperature and current dependence of the sample resistance. The temperature dependences values of Th obtained using three different methods were identical and exhibit transition of the two‐dimensional system under study from the regime of “partial inelasticity” to that of small angle scattering at temperature lowering.

Die Überhitzung der Ladungsträger wurde in p‐Typ Si/Si 0.87 Ge 0.13/Si Heterostrukturen untersucht. Die Lochtemperatur Th kann mit drei unterschiedlichen Methoden berechnet werden: Durch den Vergleich der Amplitudenänderungen der Shubnikov‐de Haas Oszillationen unter den Einflüssen von Temperatur und Stromstärke, durch den Vergleich der Änderung der Phasenrelaxationszeit im schwachen Lokalisierungseffekt bei unterschiedlichen Temperaturen, minimaler Stromstärke und bei gegebener Temperatur und unterschiedlicher Stromstärke, sowie durch den Vergleich die Abhängigkeit des Probenwiderstandes von Temperatur‐ und Stromstärke. Die Werte der Temperaturabhängigkeit von Th, die nach drei verschiedenen Methoden erhalten wurden, waren identisch und zeigten einen Übergang des betrachteten zweidimensionalen Systems vom Bereich der “partiellen Inelastizität” zur Kleinwinkelstreuung bei tieferer Temperatur.
One‐dimensional magnetophotonic crystals based on double‐layer Bi‐substituted iron garnet films
Authors: Berzhansky V. N. , Shaposhnikov A. N. , Prokopov A. R. , Karavainikov A.V. , Mikhailova T. V. , Semuk E. Y. , Sharipova M. I. , Dolgova T. V. , Fedyanin A. A. , Kotov V. A. , Golub V. O.
Published: February 2011

In the present work the fabrication process and properties of periodic one‐dimensional magnetophotonic crystal GGG (111)/M1/SiO2/[M2/M1/SiO2]4 in which as magnetic active layers were used double‐layer Bi‐substituted iron garnet films with high (Bi2.8Y0.2Fe5O12 : M1) and low (Bi1.0Y0.5Gd1.5Fe4.2.Al0.8O12 : M2) bismuth content were described. The Faraday effect and the parameters of ferromagnetic resonance were measured at different stages of magnetophotonic crystal formation. The theoretical and experimental magnetophotonic crystal transmission spectra displayed three photonic band gaps in the wavelength range of 450–1800 nm. The Faraday effect enhancement at the vicinity of the second photonic band gap at wavelength 710 nm was 2.6 times in comparison with combined (M1 + M2) layer and the effective value of Faraday rotation at the same wavelength reached –6.7°/μm.

Diese Arbeit beschreibt das Herstellungsverfahren und die Eigenschaften von periodischen eindimensionalen magnetophotonischen Kristallen GGG (111)/M1/SiO2/[M2/M1/SiO2]4 mit einer magnetoaktiven Schicht aus Doppelschicht‐Bismut‐substituierten Ferritgranat‐Filmen mit niedrigem (Bi1.0Y0.5Gd1.5Fe4.2.Al0.8O12 : M2) und hohen (Bi2.8Y0.2Fe5O12 : M1) Gehalt an Bismut. Der Faraday‐Effekt und die Parameter der ferromagnetischen Resonanz wurden in verschiedenen Stadien der Magnetophotonenkristallbildung gemessen. Theoretische und experimentelle Transmissionsspektren des Magnetophotonenkristalle zeigen drei photonische Bandlücken im Wellenlängenbereich von 450–1800 nm. Der Faraday‐Effekt in der zweiten photonische Bandlücke bei einer Wellenlänge von 750 nm ist 2,6 mal größer als in der kombinierten (M1 + M2) Schicht. Der spezifische Wert der Faraday‐Rotation auf der gleichen Wellenlänge erreicht –6,7°/μm.
Mixed magnetic state of sodium‐doped manganites and its transformation in the course of para‐ to ferromagnetic transition
Authors: Dzyublyuk V. V. , Tovstolytkin A. I. , Pogorily A. M.
Published: February 2011

The features of the transformation of the mixed magnetic state in the course of a para‐ to ferromagnetic transition have been specified for the thin films of sodium‐doped lanthanum manganites, by means of electron spin resonance measurements. It was found that the process of the ferromagnetic phase nucleation is spatially non‐uniform and includes a few successive stages upon lowering temperature. At the first step, the regions with a shape close to oblate spheroids are formed in a paramagnetic matrix. The next step includes the formation of the spheroids elongated perpendicular to a film plane, and finally, all these entities merge together to form continuous ferromagnetic regions. It is concluded that the second kind of ferromagnetic nuclei is likely to be related to the isolated crystallites, which are characterized by weakened exchange interactions.

Die Umwandlung gemischter magnetischer Zustände von Natrium‐dotierten Manganiten im Hinblick auf den Übergang von Para‐ zu Ferromagnetismus wurde an dünnen Filmen aus Natrium‐dotierten Lanthanmanganiten mittels Elektronspin‐Resonanz untersucht. Es wurde gefunden, dass der Prozess der ferromagnetischen Phasennukleation räumlich nicht einheitlich ist und einige schrittweise Stufen bei niedrigeren Temperaturen einschließt. Bei der ersten Stufe werden die Regionen mit einer Form nahe an abgeflachten Sphäroiden in einer paramagnetischen Matrix geformt. Die nächste Stufe schließt die Bildung von Sphäroiden ein, die gestreckt in Richtung der Filmebene sind. Schließlich verschmelzen diese Formen und bilden kontinuierliche ferromagnetische Regionen. Die zweite Art der ferromagnetischen Kerne ist wahrscheinlich mit den isolierten Kristalliten verbunden, die durch eine schwache Austauschwechselwirkung charakterisiert sind.
Low‐frequency two‐phonon modes step‐like dispersion in resonance raman scattering of single‐walled carbon nanotubes
Authors: Gubanov V.O. , Biliy M.M. , Rozhylo O.V. , Strelchuk V.V. , Nikolenko A.S. , Valakh M.Y. , Prylutskyy Y.I. , Ritter U. , Scharff P.
Published: February 2011

Single‐walled carbon nanotubes (SWCNT) synthesized by the arc‐discharge method were investigated by Raman spectroscopy in detail. In particular, the sharp peaks in (200.–400) cm–1 spectral range of SWCNT, associated with low‐frequency two‐phonon modes, arising from flexural 2D graphite (graphene) ZO‐ (optical branch) and ZA‐ (acoustical branch) modes, have been firstly observed.

Einwandige Kohlenstoffnanoröhren (Single‐walled Carbon Nanotubes, SWCNT), hergestellt im Lichtbogenverfahren, wurden mit Raman‐spektroskopischen Methoden detailliert untersucht. Erstmals wurden zwischen 200–400 cm–1 im Raman Spektrum zwei scharfe Peaks bei der Untersuchung von SWCNT gefunden. Die Peaks sind verbunden mit der niedrigfrequenten zwei‐Phononen‐Mode und resultieren aus den 2D‐Graphit (Graphene) Moden ZO (optischer Zweig) und ZA (akustischer Zweig).
Comparative study on protection properties of anionic surfactants (SDS, SDBS) and DNA covering of single‐walled carbon nanotubes against pH influence: luminescence and absorption spectroscopy study
Authors: Karachevtsev V.A. , Glamazda A.Y. , Plokhotnichenko A.M. , Leontiev V.S. , Linnik A.S.
Published: February 2011

The pH effect on luminescence and absorption spectra of semiconducting Single‐walled carbon nanotubes (SWNTs) (produced by CoMoCAT® method) covered with anionic surfactants (sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS)) or DNA in aqueous solutions have been studied in visible and near‐infrared (NIR) ranges. With lowering pH from 11 till 3 the emission intensity of SWNTs decreases, the largest luminescence quenching was observed with nanotubes covered by SDS intensity of which dropped by 95% and the smallest one occurred in SWNTs covered by SDBS, which decreased by 35%. The absorption intensity of the most intensive band corresponding to (6,5) nanotube (E11S transition) covered by SDBS or DNA changes weakly in the range ph = 3–11, however, in SDS surrounding the intensity of this band is reduced essentially. This observation indicated that SDBS protection ability of SWNT against pH influence is more significant compared to that of SDS. DNA takes the intermediate position among surfactants studied. The possible reason of such pH influence on optical properties of SWNTs in different surfactants or polymer surrounding is discussed.

Der Einfluss des pH‐Wertes auf die Lumineszenz‐ und Absorption‐Spektren von Kohlenstoffnanoröhren (CNT) (synthetisiert nach der CoMoCat Methode), die mit anionische Tensiden(SDBS oder SDS) oder DNA bedeckt sind, in wässriger Suspension wurde im sichtbaren Bereich und Nahinfrarotbereich untersucht. Bei Verringerung des pH‐Wertes von 11 bis auf 3 vermindert sich die Leuchtstärke der CNTs, wobei die größte Lumineszenzlöschung (um 95%) bei Nanoröhren mit SDS‐Funktionalisierung Beschichtung beobachtet wurde. Die geringste Lumineszenzlöschung (um 35%) wurde bei Nanoröhren mit SDBS‐Beschichtung beobachtet. Der Absorptionsgrad der intensiveren Bande, der einer (6,5)‐Nanoröhre mit SDBS‐ bzw. DNA‐Beschichtung entspricht (E11S‐Übergang), änderte sich wenig im pH‐Wert‐Bereich von 3 bis 11. Bei einer SDS‐Funktionalisierung sank die Intensität dieser Bande. Diese Beobachtung zeigt, dass SDBS den Einfluss des pH‐Wertes wesentlich besser zurückdrängen kann als SDS. DNA nimmt dabei einen Mittelwert ein. Mögliche Ursachen des Einflusses des pH‐Wertes auf die optische Eigenschaften der CNTs bei Beschichtung mit verschiedenen Tensiden oder Polymeren werden diskutiert.
Electrophoretic deposition of calcium phosphate nanoparticles on a nanostructured silicon surface
Authors: Epple M. , Neumeier M. , Dörr D. , LeHarzic R. , Sauer D. , Stracke F. , Zimmermann H.
Published: February 2011

Nanostructured silicon surfaces were electrophoretically coated with calcium phosphate nanoparticles. Positively charged calcium phosphate nanoparticles were synthesized by precipitation and then functionalized with poly(ethyleneimine). This permits the electrophoretic deposition on a conductive surface from a dispersion in 2‐propanol. The following parameters affected the deposition of the nanoparticles: The deposition potential, the deposition time, and the deposition temperature.

Nanostrukturierte Silicium‐Oberflächen wurden elektrophoretisch mit Calciumphosphat‐Nanopartikeln beschichtet. Die positiv geladenen Calciumphosphat‐Nanopartikel wurden durch Fällung und anschließende Funktionalisierung mit Poly(ethylenimin) hergestellt. Dies erlaubt die elektrophoretische Abscheidung aus der Dispersion in 2‐Propanol. Der Einfluss der Parameter Spannung, Zeit und Temperatur auf die Abscheidung wurde untersucht.
Controlled reduction of palladium nanoparticles on surface of chemically modified silicas
Authors: Ivashchenko N. , Tertykh V. , Yanishpolskii V. , Khainakov S. , Dikhtiarenko A.
Published: February 2011

The reduction of palladium ions by silicon hydride groups grafted to the surface of silica matrices was applied for the synthesis of palladium‐containing nanocomposites. Ordered mesoporous silicas, such as MCM‐41 and SBA‐15, along with silochrom type silica were used as supports for palladium nanoparticles in order to obtain encapsulated in pores metal particles. The synthesized nanocomposites have been studied by IR‐spectroscopy, X‐ray diffraction analysis, low‐temperature nitrogen adsorption and transmission electron microscopy.

Die Reduktion von Palladiumionen durch Siliciumhydrid‐Gruppen an der Oberfläche einer Silikatmatrix wurde für die Synthese von Palladium‐haltigen Nanokompositen eingesetzt. Geordnete mesoporöse Silikate wie MCM‐41 oder SBA‐15 wurden gemeinsam mit silochromen Silikattypen als Träger für die Palladiumnanopartikel genutzt, um sie in Metallporen einzuschließen. Die synthetisierten Nanopartikel wurden mit IR‐Spektroskopie, Röntgenbeugung, Tieftemperaturstickstoffadsorption und Transmissionselektronen‐Mikroskopie untersucht.
Estimation of the dispersion error in the numerical wave number of standard and stabilized finite element approximations of the Helmholtz equation
Authors: Steffens Lindaura Maria , Parés Núria , Díez Pedro
Published: February 2011

An estimator for the error in the wave number is presented in the context of finite element approximations of the Helmholtz equation. The proposed estimate is an extension of the ideas introduced in Steffens and D'ıez (Comput. Methods Appl. Mech. Engng 2009; 198:1389–1400). In the previous work, the error assessment technique was developed for standard Galerkin approximations. Here, the methodology is extended to deal also with stabilized approximations of the Helmholtz equation. Thus, the accuracy of the stabilized solutions is analyzed, including also their sensitivity to the stabilization parameters depending on the mesh topology. The procedure builds up an inexpensive approximation of the exact solution, using post‐processing techniques standard in error estimation analysis, from which the estimate of the error in the wave number is computed using a simple closed expression. The recovery technique used in Steffens and Díez (Comput. Methods Appl. Mech. Engng 2009; 198:1389–1400) is based in a polynomial least‐squares fitting. Here a new recovery strategy is introduced, using exponential (in a complex setup, trigonometric) local approximations respecting the nature of the solution of the wave problem. Copyright © 2011 John Wiley & Sons, Ltd.
Finite element approximation of transmission conditions in fluids and solids introducing boundary subgrid scales
Authors: Codina Ramon , Baiges Joan
Published: February 2011

Terms involving jumps of stresses on boundaries are proposed for the finite element approximation of the Stokes problem and the linear elasticity equations. These terms are designed to improve the transmission conditions between subdomains at three different levels, namely, between the element domains, between the interfaces in homogeneous domain interaction problems and at the interface between the fluid and the solid in fluid–structure interaction problems. The benefits in each case are respectively the possibility of using discontinuous pressure interpolations in a stabilized finite element approximation of the Stokes problem, a stronger enforcement of the stress continuity in homogeneous domain decomposition problems and a considerable improvement of the behavior of iterative schemes to couple the fluid and the solid in fluid–structure integration algorithms. The motivation to introduce these terms stems from a decomposition of the unknown into a conforming and a non‐conforming part, a hybrid formulation for the latter and a simple approximation for the unknowns involved in the hybrid problem. Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of high‐order curved finite elements
Authors: Sevilla Ruben , Fernández‐Méndez Sonia , Huerta Antonio
Published: February 2011

Several finite element techniques used in domains with curved boundaries are discussed and compared, with particular emphasis in two issues: the exact boundary representation of the domain and the consistency of the approximation. The influence of the number of integration points on the accuracy of the computation is also studied. Two‐dimensional numerical examples, solved with continuous and discontinuous Galerkin formulations, are used to test and compare all these methodologies. In every example shown, the recently proposed NURBS‐enhanced finite element method (NEFEM) provides the maximum accuracy for a given spatial discretization, at least one order of magnitude more accurate than classical isoparametric finite element method (FEM). Moreover, NEFEM outperforms Cartesian FEM and p‐FEM, stressing the importance of the geometrical model as well as the relevance of a consistent approximation in finite element simulations. Copyright © 2011 John Wiley & Sons, Ltd.
Differential expression of adipose tissue proteins between obesity‐susceptible and ‐resistant rats fed a high‐fat diet
Authors: Joo Jeong In , Oh Tae Seok , Kim Dong Hyun , Choi Duk Kwon , Wang Xia , Choi Jung‐Won , Yun Jong Won
Published: February 2011

One of the major questions in the field of obesity is why some humans become obese (obesity prone, OP) and others resist the development of obesity (obesity resistant, OR) when exposed to a high‐calorie diet, which has not been completely studied. Therefore, in the present study, in order to gain insight into the molecular mechanisms underlying this propensity, we have performed a comparative analysis of protein expression profiles in white adipose tissue (WAT) and brown adipose tissue (BAT) of rats fed a high‐fat diet by 2‐DE and MALDI‐TOF‐MS. Protein mapping of homogenates revealed significant alterations to a number of proteins; 60 and 70 proteins were differentially regulated in BAT and WAT, respectively. For careful interpretation of proteomic results, we categorized the identified proteins into two groups by analysis of both average spot density of pooled six rat adipose tissues and individual spot density of each adipose tissue of six rats as a function of body weight. One of the most striking findings of this study was that significant changes of Ehd1 and laminin receptor in BAT as well as antiquitin, DJ‐1 protein, and paraoxonase 2 in WAT were found for the first time in obese rats. In addition, we confirmed the increased expression of some thermogenic enzymes and decreased lipogenic enzymes in adipose tissues of OR rats by immunoblot analysis. To our knowledge, this is the first proteomic study of profiling of protein modulation in OP and OR rats, thereby providing the first global evidence for different propensities to obesity between OP and OR rats.
Measuring disease burden in the older population using the slope‐intercept method for population log‐linear estimation (SIMPLE)
Authors: Cohen Steven A. , Chui Kenneth K. H. , Naumova Elena N.
Published: February 2011

Estimating disease burden in the older
population can be problematic, due to a dearth of measurements that take into
account population dynamics, small population sizes, and age‐related disease
distribution issues. Age itself explains a substantial amount of the variability
in population disease rates. However, in many common techniques to account
for age, such as age standardization and age categorization, age is treated as
a nuisance parameter. In this paper, we present a method, the slope‐intercept
method for population log‐linear estimation (SIMPLE), to assess disease burden in the Medicare population of the US. We demonstrate the utility and potential
limitations of this straightforward and crude method in assessing age‐related
morbidity, mortality, and case‐fatality on multiple geographic levels. We highlight several examples of when this measure is most applicable using examples
abstracted from a comprehensive administrative database of hospitalizations in
older adults. Traditional measurements of disease burden are compared with the
measurements extracted from this modeling method for comparison purposes.
We also present spatial and temporal associations between the two measurements the SIMPLE method produces. Copyright © 2011 John Wiley & Sons, Ltd.