bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of neural potential of human umbilical cord blood–derived multipotent mesenchymal stem cells in response to a range of neurogenic stimuli
Authors: Zwart Isabel , Hill Andrew J. , Girdlestone John , Manca Maria F. , Navarrete Roberto , Navarrete Cristina , Jen Ling‐Sun
Published: March 2008

We investigated the neurogenic potential of full‐term human umbilical cord blood (hUCB)–derived multipotent mesenchymal stem cells (MSCs) in response to neural induction media or coculture with rat neural cells. Phenotypic and functional changes were assessed by immunocytochemistry, RT‐PCR, and whole‐cell patch‐clamp recordings. Naive MSCs expressed both mesodermal and ectodermal markers prior to neural induction. Exposure to retinoic acid, basic fibroblast growth factor, or cyclic adenosine monophosphate (cAMP) did not stimulate neural morphology, whereas exposure to dibutyryl cAMP and 3‐isobutyl‐1‐methylxanthine stimulated a neuron‐like morphology but also appeared to be cytotoxic. All protocols stimulated increases in expression of the neural precursor marker nestin, but expression of mature neuronal or glial markers MAP2 and GFAP was not observed. Nestin expression increases were serum level dependent. Electrophysiological properties of MSCs were studied with whole‐cell patch‐clamp recordings. The MSCs possessed no ionic currents typical of neurons before or after neural induction protocols. Coculture of hUCB‐derived MSCs and rat neural cells induced some MSCs to adopt an astrocyte‐like morphology and express GFAP protein and mRNA. Our data suggest hUCB‐derived MSCs do not transdifferentiate into mature functioning neurons in response to the above neurogenic protocols; however, coculture with rat neural cells led to a minority adopting an astrocyte‐like phenotype. © 2008 Wiley‐Liss, Inc.
Impaired activation of celiac ganglion neurons in vivo after damage to their sympathetic nerve terminals
Authors: Mundinger Thomas O. , Mei Qi , Taborsky Gerald J.
Published: March 2008

Because damage to sympathetic nerve terminals occurs in a variety of diseases, we tested the hypothesis that nerve terminal damage per se is sufficient to impair ganglionic neurotransmission in vivo. First, we measured the effect of nerve terminal damage produced by the sympathetic nerve terminal toxin 6‐hydroxydopamine (6‐OHDA) on ganglionic levels of several neurotrophins thought to promote neurotransmission. 6‐OHDA‐induced nerve terminal damage did not decrease the expression of neurotrophin‐4 or brain‐derived neurotrophic factor mRNA in the celiac ganglia but did decrease the ganglionic content of both nerve growth factor protein (nadir = −63%) and the mRNA of the alpha‐3 subunit of the nicotinic cholinergic receptor (nadir = −49%), a subunit required for neurotransmission. Next, we tested whether this degree of receptor deficiency was sufficient to impair activation of celiac ganglia neurons. Impaired fos mRNA responses to nicotine administration in the celiac ganglia of 6‐OHDA‐pretreated rats correlated temporally with suppressed expression of functional nicotinic receptors. We verified by Fos protein immunohistochemistry that this ganglionic impairment was specific to principal ganglionic neurons. Last, we tested whether centrally initiated ganglionic neurotransmission is also impaired following nerve terminal damage. The principal neurons in rat celiac ganglia were reflexively activated by 2‐deoxy‐glucose‐induced glucopenia, and the Fos response in the celiac ganglia was markedly inhibited by pretreatment with 6‐OHDA. We conclude that sympathetic nerve terminal damage per se is sufficient to impair ganglionic neurotransmission in vivo and that decreased nicotinic receptor production is a likely mediator. © 2008 Wiley‐Liss, Inc.
Bilirubin as an endogenous modulator of neurotrophin redox signaling
Authors: Mancuso Cesare , Capone Caterina , Ranieri Sofia Chiatamone , Fusco Salvatore , Calabrese Vittorio , Eboli Maria Luisa , Preziosi Paolo , Galeotti Tommaso , Pani Giovambattista
Published: March 2008

Bilirubin is neurotoxic upon excess accumulation in the brain, but it also plays important physiological roles related to its antioxidant properties. Here we report that exposure of PC12 and primary rat cerebellar granule neurons to bilirubin (0.5–10 μM) drastically decreases nerve growth factor (NGF)/brain‐derived neurotrophic factor signaling to Akt and extracellular signal‐regulated kinases (ERKs), indicating a direct interference of the molecule with crucial prosurvival signaling pathways. This effect likely involves the scavenging capacity of bilirubin, the latter being able to inhibit, in PC12 cells, accumulation of intracellular reactive oxygen species and phosphorylation of Akt and ERKs in response to extracellular hydrogen peroxide. Interestingly, in the absence of exogenous growth factor, bilirubin elicited the phosphorylation of ERKs and of the cAMP responsive element binding (CREB) transcription factor, a signature of NGF‐dependent survival signaling. These growth factor‐like signaling effects were paralleled by the induction of the neuronal nitric oxide synthase (nNOS) and generation of nitric oxide (NO). Pharmacological dissection of the signaling cascade triggered by bilirubin revealed that phosphorylation of ERKs requires NO signaling through soluble guanylyl cyclase, and, further upstream, influx of extracellular calcium is necessary for nNOS induction and NO release, likely through calcium‐dependent phosphorylation of CREB. Importantly, the cascade elicited by bilirubin through NO and ERK is cytoprotective, as revealed by exacerbated bilirubin toxicity in cultures treated by either NOS or MEK inhibitors. Taken together, these observations indicate an important action of bilirubin on redox signaling by neurotrophins, with either inhibitory or agonistic effects based on growth factor availability. © 2008 Wiley‐Liss, Inc.
Hypothesis of active components in volatile oil from a Chinese herb formulation, ‘Shao‐Fu‐Zhu‐Yu decoction’, using GC‐MS and chemometrics
Authors: Su Shulan , Hua Yongqing , Duan Jin‐ao , Shang Erxin , Tang Yuping , Bao Xingjie , Lu Yin , Ding Anwei
Published: March 2008

Traditional Chinese medicine (TCM) with few or no side effects has increasingly attracted attention all over the world. However, the bioactive components and the therapeutic mechanisms are usually not understood because of the complex chemical compositions of these medicines. In this paper, GC–MS coupled with a chemometric method was developed for analysis of active components in volatile oil from a Chinese herb formulation, “Shao‐Fu‐Zhu‐Yu Decoction”. The volatile oils, obtained by hydrodistillation from “Shao‐Fu‐Zhu‐Yu Decoction” (SFZYD) and its constituent herbs with abundant volatile oil (Angelica sinensis, Ligusticum chuanxiong, Cinnamomum cassia, Foeniculum vulgare, Zingiber officinale), were chemically analyzed using GC–MS and bioassayed using oxytocin‐induced uterine contraction assay in vitro. Then, a mathematic model relating the chemical compositions and their activities in inhibiting mice uterine contraction was established for hypothesis of the bioactive compounds based on chemometrics. As a result, nine compounds which might contribute to the inhibition of oxytocin‐induced uterine contraction were selected, and the activities of some of them were further confirmed by our experiments and/or the literature. The data suggest that the developed method is helpful for screening bioactive components from complex mixtures, such as the extracts of TCM.
Ultra‐performance LC/TOF MS analysis of medicinal Panax herbs for metabolomic research
Authors: Xie Guoxiang , Plumb Robert , Su Mingming , Xu Zhaohui , Zhao Aihua , Qiu Mingfeng , Long Xiangbao , Liu Zhong , Jia Wei
Published: March 2008

In this study, metabolite profiling of five medicinal Panax herbs including Panax ginseng (Chinese ginseng), Panax notoginseng (Sanchi), Panax japonicus (Rhizoma Panacis Majoris), Panax quinquefolium L. (American ginseng), and P. ginseng (Korean ginseng) were performed using ultra‐performance LC‐quadrupole TOF MS (UPLC‐QTOFMS) and multivariate statistical analysis technique. Principal component analysis (PCA) of the analytical data showed that the five Panax herbs could be separated into five different groups of phytochemicals. The chemical markers such as ginsenoside Rf, 20(S)‐pseudoginsenoside F11, malonyl gisenoside Rb1, and gisenoside Rb2 accountable for such variations were identified through the loadings plot of PCA, and were identified tentatively by the accurate mass of TOFMS and partially verified by the available reference standards. Results from this study indicate that the proposed method is reliable for the rapid analysis of a group of metabolites present in herbal medicines and other natural products and applicable in the differentiation of complex samples that share similar chemical ingredients.
Human and spatial dimensions of retail density: Revisiting the role of perceived control
Authors: Rompay Thomas J. L. van , Galetzka Mirjam , Pruyn Ad T. H. , Garcia Jaime Moreno
Published: March 2008

Previous research in environmental psychology and consumer behavior has demonstrated mostly negative effects of human density on consumer experience in retail settings. The effects of spatial density, however, have received scant attention. Results from previous studies show that retail density affects shoppers' emotional and behavioral responses through perceived control.Work in social psychology, however, indicates that there are differences in the extent to which people strive for control, suggesting that having control in retail settings may be more important to some consumers than to others. In the experimental study reported in this paper, the effects of both forms of retail density were studied as a function of consumers' desire for control. Results indicate that the effects of human and spatial density vary with consumers' desire for control. Theoretical and managerial implications are discussed. © 2008 Wiley Periodicals, Inc.
Corporate image and product similarity—Assessing major demand drivers for counterfeits in a multi‐country study
Authors: Penz Elfriede , Stöttinger Barbara
Published: March 2008

The demand for counterfeits has become a major headache for brand name manufacturers across the globe. This paper investigates two key demand drivers: (1) corporate image, in the form of evaluative and descriptive judgments of the original manufacturer and the counterfeiter, and (2) product attributes, split into physical, beneficial, and symbolic aspects, and their impact on consumers' intentions to buy fakes, based on the tripartite model of attitudes and by applying Peabody's concept of unconfounding evaluative and descriptive judgments (Peabody, 1984; Peabody & Goldberg, 1989; Saucier, 1994; Saucier, Ostendorf, & Peabody, 2001). In total, 1846 consumers were surveyed in six different countries: the United States, Austria, Mexico, Sweden, Slovakia, and the Ukraine. According to the results, corporate image and product characteristics show a strong impact on the consumers' intention to buy fakes. The relative importance of the concepts' sub‐dimensions, however, differs substantially across the countries selected. With respect to the corporate image, respondents use mainly emotional responses to describe the image of original manufacturers and counterfeiters, and they clearly distinguish them based on image. Product‐level comparisons revealed that looks, functionality, image, and physical appearance differed between originals and fakes across countries, whereas quality and durability of originals and fakes are perceived very similarly. The paper closes with managerial implications and avenues for future research. © 2008 Wiley Periodicals, Inc.
Consumers' preference shifts under the deletion of common features with varying attractiveness: An examination of competing explanations
Authors: Chiou Wen‐Bin
Published: March 2008

When necessary, marketers might delete common features of a promotional package that have also been deleted by competitors. This research examined two hypotheses of how the deletion of common features of varying attractiveness affects consumers' prior preferences. When participants were informed that a common feature of their available choices was unavailable, their preference decreased relatively for one alternative compared with another alternative. This effect was not contingent on the deleted feature's attractiveness. The findings reveal that the deletion of common features tends to motivate consumers to disregard the overall utility of the prior preferred option rather than to activate confirmatory reasoning for consolidating a previous choice. Thus, by deleting common features of a promotional package, marketers risk altering consumers' prior preferences and may lose their advantage over competitors. © 2008 Wiley Periodicals, Inc.
Implementing management tools in Turkish public hospitals: the impact of culture, politics and role status
Authors: Ozturk Ali Osman , Swiss James E.
Published: March 2008

The government of Turkey has attempted to substantially improve the management of its public hospitals. However, an analysis of the performance of the quality certified hospitals finds only minor improvements. This study seeks to explain these disappointing results by interviewing 46 hospital managers and employees about the successes and failures of the management reform effort. The interviews suggest that traditional Turkish organisational culture often hinders attempts to decrease hierarchy, but, more positively, it also encourages the use of frontline teams and group rewards. Moreover, Turkey's hybrid system of allowing public doctors to maintain private practices has provided doctors with both the resources and the incentives to fight management reform efforts. Finally, organisational decentralisation in Turkey has evoked fierce political opposition, ironically even from many pro‐modernising forces that fear it could increase the power of Islamic fundamentalists. Turkey's experience suggests a number of broader points about management reform in non‐western societies. It suggests that decentralisation can often impede, rather than strengthen the other aspects of management reform; that a hybrid market organisation is often harder to move toward market efficiencies than a purely governmental one; and that national cultures should help guide the order in which reform tools are implemented. Copyright © 2008 John Wiley & Sons, Ltd.
Does homeownership counseling affect the prepayment and default behavior of affordable mortgage borrowers?
Authors: Quercia Roberto , Spader Jonathan
Published: March 2008

The lack of industrywide data on homeownership education and counseling (HEC) programs has severely limited evaluation. In particular, very little evidence exists on the relationship between HEC completion and loan prepayment, an outcome of interest to both mortgage lenders and consumer advocates. Where mortgage prepayment directly influences the sustainability of affordable mortgage products, it also reflects the ability of underserved borrowers to access lower‐cost credit through refinancing. This study uses a uniquely rich data set to examine the impact of HEC completion on prepayment and defaultamongborrowers receivingHECfrom a variety of providers across 42 states. The loans, originated between 1999 and 2003, are observed through the first quarter of 2006, a period in which strong housing appreciation and decreasing interest rates generated substantial refinancing activity. Using a competing risks model of mortgage prepayment and default, we find that HEC programs based on classroom instruction and individual counseling improve a borrower's exercise of the mortgage prepayment option, but that programs based on home study or telephone counseling did not affect borrower behavior. Counseling shows no effect on default propensities. © 2008 by the Association for Public Policy Analysis and Management.
Does the public sector outperform the nonprofit and for‐profit sectors? Evidence from a national panel study on nursing home quality and access
Authors: Amirkhanyan Anna A. , Kim Hyun Joon , Lambright Kristina T.
Published: March 2008

Are public and private organizations fundamentally different? This question has been among the most enduring inquiries in public administration. Our study explores the impact of organizational ownership on two complementary aspects of performance: service quality and access to services for impoverished clients. Derived from public management research on performance determinants and nursing home care literature, our hypotheses stipulate that public, nonprofit, and forprofit nursing homes use different approaches to balance the strategic tradeoff between two aspects of performance. Panel data on 14,423 facilities were analyzed to compare measures of quality and access across three sectors using different estimation methods. Findings indicate that ownership status is associated with critical differences in both quality and access. Public and nonprofit organizations are similar in terms of quality, and both perform significantly better than their forprofit counterparts. When compared to nonprofit and, in some cases, for‐profit facilities, public nursing homes have a significantly higher share of Medicaid recipients. The paper proposes strategies to address the identified long‐term care divide. © 2008 by the Association for Public Policy Analysis and Management.
Welfare and child support: Complements, not substitutes
Authors: Cancian Maria , Meyer Daniel R. , Caspar Emma
Published: March 2008

In most states, child support paid on behalf of Temporary Assistance for Needy Families (TANF) participants is used to offset TANF and child support administrative expenditures; this policy primarily benefits taxpayers. In contrast, Wisconsin allowed most custodial parents to keep all support paid on their behalf. This policy, which treats welfare and child support as complements, was evaluated through an experimental design. This paper reports the key results of the experimental evaluation, using state administrative data to examine the effects on child support outcomes and governmental cost. We find that when custodial mothers keep all child support paid on their behalf, paternity establishment occurs more quickly, noncustodial fathers are more likely to pay support, and custodial families receive more support. These outcomes are achieved at no significant governmental cost. © 2008 by the Association for Public Policy Analysis and Management.
Variability of polymorphic families of three types of xylanase inhibitors in the wheat grain proteome
Authors: Croes Evi , Gebruers Kurt , Robben Johan , Noben Jean‐Paul , Samyn Bart , Debyser Griet , Van Beeumen Jozef , Delcour Jan A. , Courtin Christophe M.
Published: March 2008

Cereals contain proteinaceous inhibitors of endo‐β‐1,4‐xylanases (E.C.3.2.1.8, xylanases). Since these xylanase inhibitors (XIs) are only active against xylanases of microbial origin and do not interact with plant endogenous xylanases, they are believed to act as a defensive barrier against phytopathogenic attack. So far, three types of XIs have been identified, i.e. Triticum aestivum XI (TAXI), xylanase inhibiting protein (XIP), and thaumatin‐like XI (TLXI) proteins. In this study the variation in XI forms present in wheat grain was elucidated using high‐resolution 2‐DE in combination with LC‐ESI‐MS/MS and biochemical techniques. Reproducible 2‐DE fingerprints of TAXI‐, XIP‐, and TLXI‐type XIs, selectively purified from whole meal of three European wheat cultivars using cation exchange chromatography followed by affinity chromatography, were obtained using a pH‐gradient of 6 to 11 and a molecular mass range of 10 to 60 kDa. Large polymorphic XI families, not known to date, which exhibit different pI‐ and/or molecular mass values, were visualised by colloidal CBB staining. Identification of distinct genetic variants by MS/MS‐analysis provides a partial explanation for the observed XI heterogeneity. Besides genetic diversity, PTMs, such as glycosylation, account for the additional complexity of the 2‐DE patterns.
Protein expression profile of Gluconacetobacter diazotrophicus PAL5, a sugarcane endophytic plant growth‐promoting bacterium
Authors: Lery Leticia M. S. , Coelho Ana , von Kruger Wanda M. A. , Gonçalves Mayla S. M. , Santos Marise F. , Valente Richard H. , Santos Eidy O. , Rocha Surza L. G. , Perales Jonas , Domont Gilberto B. , Teixeira Katia R. S. , Bisch Paulo M.
Published: March 2008

This is the first broad proteomic description of Gluconacetobacter diazotrophicus, an endophytic bacterium, responsible for the major fraction of the atmospheric nitrogen fixed in sugarcane in tropical regions. Proteomic coverage of G. diazotrophicus PAL5 was obtained by two independent approaches: 2‐DE followed by MALDI‐TOF or TOF‐TOF MS and 1‐DE followed by chromatography in a C18 column online coupled to an ESI‐Q‐TOF or ESI‐IT mass spectrometer. The 583 identified proteins were sorted into functional categories and used to describe potential metabolic pathways for nucleotides, amino acids, carbohydrates, lipids, cofactors and energy production, according to the Enzyme Commission of Enzyme Nomenclature (EC) and Kyoto Encyclopedia of genes and genomes (KEGG) databases. The identification of such proteins and their possible insertion in conserved biochemical routes will allow comparisons between G. diazotrophicus and other bacterial species. Furthermore, the 88 proteins classified as conserved unknown or unknown constitute a potential target for functional genomic studies, aiming at the understanding of protein function and regulation of gene expression. The knowledge of metabolic fundamentals and coordination of these actions are crucial for the rational, safe and sustainable interference on crops. The entire dataset, including peptide sequence information, is available as Supporting Information and is the major contribution of this work.
The mouse sperm proteome characterized via IPG strip prefractionation and LC‐MS/MS identification
Authors: Baker Mark A. , Hetherington Louise , Reeves Gabi M. , Aitken R. John
Published: March 2008

Proteomic profiling of the mouse spermatozoon has generated a unique and valuable inventory of candidates that can be mined for potential contraceptive targets and to further our understanding of the PTMs that regulate the functionality of this highly specialized cell. Here we report the identification of 858 proteins derived from mouse spermatozoa, 23 of which demonstrated testis only expression. The list contained many proteins that are known constituents of murine spermatozoa including Izumo, Spaca 1, 3, and 5, Spam 1, Zonadhesin, Spesp1, Smcp, Spata 6, 18, and 19, Zp3r, Zpbp 1 and 2, Spa17, Spag 6, 16, and 17, CatSper4, Acr, Cylc2, Odf1 and 2, Acrbp, and Acrv1. Certain protein families were highly represented in the proteome. For example, of the 42 gene products classified as proteases, 26 belonged to the 26S‐proteasome. Of the many chaperones identified in this proteome, eight proteins with a TCP‐1 domain were found, as were seven Rab guanosine triphosphatases. Finally, our list yielded three putative seven‐transmembrane proteins, two of which have no known tissue distribution, an extragenomic progesterone receptor and three unique testis‐specific kinases all of which may have some potential in the future regulation of male fertility.
A simple and highly successful C‐terminal sequence analysis of proteins by mass spectrometry
Authors: Kuyama Hiroki , Shima Keisuke , Sonomura Kazuhiro , Yamaguchi Minoru , Ando Eiji , Nishimura Osamu , Tsunasawa Susumu
Published: March 2008

A simple and efficient method for C‐terminal sequencing of proteins has long been pursued because it would provide substantial information for identifying the covalent structure, including post‐translational modifications. However, there are still significant impediments to both direct sequencing from C termini of proteins and specific isolation of C‐terminal peptides from proteins. We describe here a highly successful, de novo C‐terminal sequencing method of proteins by employing succinimidyloxycarbonylmethyl tris (2,4,6‐trimethoxyphenyl) phosphonium bromide and mass spectrometry.
Precision enhancement of MALDI‐TOF MS using high resolution peak detection and label‐free alignment
Authors: Tracy Maureen B. , Chen Haijian , Weaver Dennis M. , Malyarenko Dariya I. , Sasinowski Maciek , Cazares Lisa H. , Drake Richard R. , Semmes O. John , Tracy Eugene R. , Cooke William E.
Published: March 2008

We have developed an automated procedure for aligning peaks in multiple TOF spectra that eliminates common timing errors and small variations in spectrometer output. Our method incorporates high‐resolution peak detection, re‐binning, and robust linear data fitting in the time domain. This procedure aligns label‐free (uncalibrated) peaks to minimize the variation in each peak's location from one spectrum to the next, while maintaining a high number of degrees of freedom. We apply our method to replicate pooled‐serum spectra from multiple laboratories and increase peak precision (t/σt) to values limited only by small random errors (with σt less than one time count in 89 out of 91 instances, 13 peaks in seven datasets). The resulting high precision allowed for an order of magnitude improvement in peak m/z reproducibility. We show that the CV for m/z is 0.01% (100 ppm) for 12 out of the 13 peaks that were observed in all datasets between 2995 and 9297 Da.
Optically induced strain relaxation in anisotropically strained M ‐plane GaN films
Authors: Flissikowski T. , Brandt O. , Misra P. , Grahn H. T.
Published: March 2008

We study the anisotropic in‐plane strain in M ‐plane GaN films by photoreflectance, photoluminescence, Raman, and time‐resolved pump‐and‐probe spectroscopy. We find that a highly strained film partially relaxes, if it is pumped by an intense optical pulse. The strain relaxation can be observed by a shift of the E2‐Raman line to lower energies and by a shift of the fundamental interband transition energies in the photoreflectance spectra. The photoluminescence intensity of the exposed areas is significantly reduced as compared to the one for areas, which have not been exposed to the intense optical pulse. This suggests that the strain relaxation is connected to the introduction of defects, which can act as non‐radiative recombination centers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of buffer‐trapping effects on gate lag, drain lag and current collapse in AlGaN/GaN HEMTs
Authors: Horio K. , Nakajima A.
Published: March 2008

Transient simulations of AlGaN/GaN HEMTs are performed in which a deep donor and a deep acceptor are considered in a semi‐insulating buffer layer. Quasi‐pulsed I‐V curves are derived from the transient characteristics, and are compared with steady‐state I‐V curves. It is shown that the lag phenomena and current collapse could be reproduced. Particularly, the gate lag is correlated with relatively high source access resistance of the FETs. The current collapse is shown to bemore pronounced when the deep‐acceptor density in the buffer layer is higher and when an off‐state drain voltage is higher, because trapping effects become more significant. It is suggested that to minimize current collapse in AlGaN/GaN HEMTs, an acceptor density in the buffer layer should be made low, although the current cutoff behavior may be degraded. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Filling the green gap: A first‐principles study of the LiMg1‐xZnxN alloy
Authors: Walsh Aron , Wei Su‐Huai
Published: March 2008

The lack of an efficient emitter in the 500‐600nm range is limiting the adoption of LEDs for indoor lighting applications. The degradation in performance of current InGaN alloys in this range is due to the large lattice mismatch between InN and GaN and associated alloy phase instabilities. We propose and investigate, using first‐principles methods, the electronic structure of an alternative LiMg1‐xZnxN alloy which has the potential to fill this gap. The small lattice mismatch between LiMgN and LiZnN, along with electronic band gaps spanning the visible range, make them, in principle, ideal candidates for white LED applications. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bluish‐green semipolar GaInN/GaN light emitting diodes on {1$ \bar 1 $01} GaN side facets
Authors: Wunderer T. , Lipski F. , Hertkorn J. , Brückner P. , Scholz F. , Feneberg M. , Schirra M. , Thonke K. , Chuvilin A. , Kaiser U.
Published: March 2008

Bluish‐green semipolar GaInN/GaN light emitting diodes were realized on the {1$ \bar 1 $01} side facets of selectively grown GaN stripes with an on‐wafer optical output power of 240 mW@20mA for about 500 nm emission wavelength. Structural investigations using TEM, SEM, HRXRD and AFM could be related to the luminescence properties in PL and CL. The defect‐related luminescence peaks at 3.3 eV and 3.41 eV, typically observed in non‐ and semipolar GaN, could be eliminated in our facet LEDs by optimized growth conditions. Furthermore, a 50% higher indium incorporation for these {1$ \bar 1 $01} facets compared to c ‐plane growth is found, what helps significantly to achieve longer wavelength emission in spite of the reduced Quantum Confined Stark Effect. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High resolution Laplace deep level transient spectroscopy studies of electron and hole traps in n‐type GaN
Authors: Emiroglu D. , Evans‐Freeman J. , Kappers M. J. , McAleese C. , Humphreys C. J.
Published: March 2008

Deep Level Transient Spectroscopy (DLTS) and Laplace DLTS (LDLTS) have been applied to MOVPE‐grown n‐type GaN, grown at 1020 °C on c‐plane sapphire. DLTS measured up to 600 K initially recorded three peaks due to electron emission. However, when the next rate window was sampled immediately afterwards, the DLTS scan showed a large negative peak which dominated the scan at 410K. The polarity of the feature means that this is due to hole emission. An electron trap initially present at 400 K in the DLTS spectrum gradually disappeared up to a measurement temperature of 520 K; beyond this the hole trap was observed. It then remained detectable by DLTS for up to one week, although cooling under bias decreased its intensity severely. LDLTS reveals that this hole trap is not a simple point defect as it has three emission rates. It is discussed in the context of the VGa‐ON(x) defect, where different emission rates present could reflect VGa complexed with different numbers of O atoms. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inhibition of Ulmus davidiana Planch (Ulmaceae) on bone resorption mediated by processing of Cathepsin K in cultured mouse osteoclasts
Authors: Kim Kyung‐Woon , Park Jun‐Sung , Kim Kap‐Sung , Jin Un‐Ho , Kim June‐Ki , Suh Seok‐Jong , Kim Cheorl‐Ho
Published: March 2008

Ulmus davidiana Planch (Ulmaceae) (UD) has long been known to be antiinflammatory in traditional Korean medicine. This experiment investigated the effects of UD on bone resorption using bone cell culture. Different concentrations of crude extract of UD were added to mouse bone cell culture. The mitochondrial activity of the bone cells after exposure of UD was determined by colorimetric 3‐(4,5‐dimethylthiazolyl‐2)‐2,5‐diphenyltetrazolium bromide (MTT). It was demonstrated that UD has potential effects on bone cell culture without cytotoxicity. The most effective concentration of UD in bone cells was 100 µg/mL. Cathepsin K (Cat K) is the major cysteine protease expressed in osteoclasts and is thought to play a key role in matrix degradation during bone resorption. When mouse long bone cells including osteoclasts and osteoblasts were treated with UD, UD prevented the osteoclast‐mediated intracellular processing of Cat K, suggesting that UD may disrupt the intracellular transport of pro Cat K. Since secreted proenzymes have the potential to reenter the cell via the mannose‐6‐phosphate (M6P) receptor, to prevent this possibility, UD was tested in the absence or presence of M6P. Inhibition of Cat K processing by UD was observed in a dose‐dependent manner. Furthermore, the addition of M6P resulted in enhanced potency of UD. UD dose‐dependently inhibited in vitro bone resorption with a potency similar to that observed for inhibition of Cat K processing. Copyright © 2008 John Wiley & Sons, Ltd.
Capsaicin modulates pulmonary antioxidant defense system during benzo(a)pyrene‐induced lung cancer in swiss albino mice
Authors: Anandakumar P. , Kamaraj S. , Jagan S. , Ramakrishnan G. , Vinodhkumar R. , Devaki T.
Published: March 2008

The effect of a pungent ingredient of red pepper, capsaicin, on oxidative stress induced changes in the antioxidant defense system by benzo(a)pyrene in the lungs of mice was studied. Oral gavage administration of benzo(a)pyrene (50 mg/kg body weight) to mice led to a marked increase in oxidative stress indicated by alterations in pulmonary lipid peroxidation, enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione‐S‐transferase and glucose‐6‐phosphate dehydrogenase) and non‐enzymic antioxidants (reduced glutathione, vitamin C, vitamin E and vitamin A). Pre‐co‐treatment with capsaicin (10 mg/kg body weight i.p.) restored cellular normalcy, highlighting the antioxidant potential of capsaicin in mitigating the oxidative stress mediated damage produced during benzo(a)pyrene‐induced lung cancer. Copyright © 2008 John Wiley & Sons, Ltd.
How to justify teaching false science
Authors: Slater Matthew H.
Published: March 2008

We often knowingly teach false science. Such a practice conflicts with a prima facie pedagogical value placed on teaching only what is true. I argue that only a partial dissolution of the conflict is possible: the proper aim of instruction in science is not to provide an armory of facts about what things the world contains, how they interact, and so on, but rather to contribute to an understanding of how science as a human endeavor works and what sorts of facts about the world science aims to provide. Such an aim legislates for an increased prominence of history and philosophy in even secondary science education. © 2008 Wiley Periodicals, Inc. Sci Ed 92:526–542, 2008
Students' inventory of social actors concerned by the controversy surrounding cellular telephones: A case study
Authors: Pouliot Chantal
Published: March 2008

The present article scrutinizes the manner with which a group of three postsecondary students (in Quebec, Canada) describe the social actors concerned by the controversy surrounding cellular telephones. The study was conducted on the basis of an ethnographic approach. Participant observation was performed by the researcher for 3 hours during each of 15 weeks. The theoretical framework developed by Callon, Lascoumes, and Barthe (2001) was drawn on to show how the group assigns roles relating to public representation and the production of legitimate knowledges; in particular, it assigns to scientists the role of conducting research; to government the roles of building citizens' awareness about the risks related to cellular telephone use, protecting users, and guiding the conduct of the cellular telephone industry; and to citizens the roles of becoming/staying informed and of making limited use of cellular telephones. The study reported here also illustrates that, in the process, the group airs their views concerning the terms best suited to defining the subject of the controversy, constituting research “collectives,” and disseminating knowledge. One main conclusion is that science education research projects drawing on the contributions of Callon et al. (2001) hold out considerable promise in terms of relevance and fruitfulness. © 2008 Wiley Periodicals, Inc. Sci Ed 92:543–559, 2008
Toxins from cone snails: properties, applications and biotechnological production
Authors: Becker Stefan , Terlau Heinrich
Published: March 2008

Cone snails are marine predators that use venoms to immobilize their prey. The venoms of these mollusks contain a cocktail of peptides that mainly target different voltage- and ligand-gated ion channels. Typically, conopeptides consist of ten to 30 amino acids but conopeptides with more than 60 amino acids have also been described. Due to their extraordinary pharmacological properties, conopeptides gained increasing interest in recent years. There are several conopeptides used in clinical trials and one peptide has received approval for the treatment of pain. Accordingly, there is an increasing need for the production of these peptides. So far, most individual conopeptides are synthesized using solid phase peptide synthesis. Here, we describe that at least some of these peptides can be obtained using prokaryotic or eukaryotic expression systems. This opens the possibility for biotechnological production of also larger amounts of long chain conopeptides for the use of these peptides in research and medical applications.
Surgical Resection of Stage IV Colorectal Cancer and Prognosis
Authors: Katoh Hiroshi , Yamashita Keishi , Kokuba Yukihito , Satoh Takeo , Ozawa Heita , Hatate Kazuhiko , Ihara Atsushi , Nakamura Takatoshi , Onosato Wataru , Watanabe Masahiko
Published: March 2008

Background

Colorectal cancer (CRC) harbors accumulated genetic alterations with cancer progression, which results in uncontrollable disease. To regulate the most malignant CRC, we have to know the most dismal phenotype of stage IV disease.

Methods

A retrospective review of the Kitasato University Hospital was performed (from 1990 to 2001) to extract the 162 resected stage IV CRC. Clinical variables were tested for their relationship to survival in a multivariate prognostic analysis and revealed the interaction of the prognostic factors.

Results

In stage IV CRC with noncurable resection, the most robust univariate predictors for poor prognosis were preoperative high value of CA19‐9, peritoneal dissemination, depth of invasion, age, extent of liver metastases, pathologic lymph node metastasis status, and gender as tumor factors, and postoperative therapy, perioperative transfusion, and lymph node dissection extent as treatment factors. Among these factors, postoperative therapy (p< 0.0001), perioperative transfusion (0.0002), CA19‐9 (0.001), extent of liver metastases (0.004), and peritoneal dissemination (0.02) were identified as independent prognostic factors by multivariate analysis. Interestingly, among the independent prognostic factors, treatment factors did not depend upon tumor factors and the combination of the three tumor factors (CA19‐9, extent of liver metastases, and peritoneal dissemination) can clearly classify the patients into the definite prognostic groups.

Conclusion

Our results suggested that the most dismal CRC harbors three definite vectors that may represent the strongest phenotype of putative systemic immune (CA19‐9), distant metastasis (extent of liver metastases), and local progression (peritoneal dissemination).
Evidence for the Role of Perioperative PTH Measurement after Total Thyroidectomy as a Predictor of Hypocalcemia
Authors: Grodski Simon , Serpell Jonathan
Published: March 2008

Background

Total thyroidectomy is now accepted worldwide as the standard surgical procedure for the management of benign bilateral nodular thyroid disease. Hypocalcemia is the most common complication of that procedure and a variety of strategies for diagnosing and managing post‐thyroidectomy hypocalcemia have been advocated. Increasingly, the use of intact parathyroid hormone (PTH) has been utilized to try to predict those patients at risk of developing post‐thyroidectomy hypocalcemia.

Methods

A Medline search of English language literature was performed and we reviewed the evidence in relation to the following three issues: the accuracy of PTH in predicting hypocalcemia, the optimal timing for measuring PTH, and the routine use of oral calcium supplements.

Results

Post‐thyroidectomy PTH levels accurately predict hypocalcemia but lack 100% accuracy. Progressive and severe hypocalcemia is unlikely in the setting of a normal PTH level and hence PTH can be cautiously used to facilitate discharge within 24 h for many patients. In addition, PTH levels can be used to implement early treatment with calcium and/or vitamin D supplements to reduce the incidence and severity of hypocalcemia. A single PTH measurement taken any time from 10 min to several hours postoperative will provide equally accurate results for predicting post‐thyroidectomy hypocalcemia. Routine use of oral calcium supplements may reduce the incidence and severity of post‐thyroidectomy hypocalcemia.

Conclusion

Postoperative PTH can be used to stratify the risk of patients developing hypocalcemia after thyroidectomy. In addition, the routine use of oral calcium supplements can lead to decreased incidence and severity of post‐thyroidectomy hypocalcemia. Protocols based on PTH and the routine use of oral calcium supplements can lead to improved patient outcomes after thyroidectomy.
Preoperative Neutrophil‐to‐Lymphocyte Ratio as a Prognostic Predictor after Curative Resection for Hepatocellular Carcinoma
Authors: Gomez D. , Farid S. , Malik H. Z. , Young A. L. , Toogood G. J. , Lodge J. P. A. , Prasad K. R.
Published: March 2008

Background

This study was designed to evaluate the impact of an elevated preoperative neutrophil‐to‐lymphocyte ratio (NLR) on outcome after curative resection for hepatocellular carcinoma (HCC).

Methods

Patients undergoing resection for HCC from January 1994 to May 2007 were identified from the hepatobiliary database. Demographics, laboratory analyses, and histopathology data were analyzed.

Results

A total of 96 patients were identified with a median age at diagnosis of 65 (range, 15–85) years. The 1‐, 3‐, and 5‐year overall survival rates were 80%, 58%, and 52%, respectively. Although the presence of microvascular invasion, NLR ≥5, and R1 resection margin were adverse predictors of overall survival, there were no independent predictors identified on multivariate analysis. The 1‐, 3‐, and 5‐year disease‐free survival rates were 74%, 63%, and 57%, respectively. Preoperative tumor biopsy, NLR ≥ 5, multiple liver tumors, microvascular invasion, and R1 resection margin were all predictors of poorer disease‐free survival. Multivariate analysis showed that a NLR ≥ 5 and R1 resection margin were independent predictors of poorer disease‐free survival. The median disease‐free survival of those with a NLR ≥ 5 was 8 months compared with 18 months for those with a NLR < 5.

Conclusion

Preoperative NLR ≥ 5 was an adverse predictor of disease‐free and overall survival.
Preventing acute infection in total hip prostheses implanted after external fixation of the femur: is there a need for a staged procedure?
Authors: Massè A. , Aprato A. , Guzzi Susini E.
Published: March 2008

We report two cases of acute infection of an uncemented femoral component in a hip prosthesis implanted after external fixation of a femoral fracture. In both cases, the surgical access did not cross over the pin scars. When the prosthesis was implanted the stem crossed one or more pin tracts. The preoperative clinical examination, laboratory tests and bone scintigraphy with marked granulocytosis did not show signs of local infection in either case. We suggest that every patient destined to receive a prosthesis after external fixation should be treated with a staged procedure, the first step being excision of the soft tissues around the pin tracts and curettage or drilling of the bony holes, followed by prosthesis implant.
Elastofibroma dorsi: 8 case reports and a literature review
Authors: Muratori F. , Esposito M. , Rosa F. , Liuzza F. , Magarelli N. , Rossi B. , Folath H. M. , Pacelli F. , Maccauro G.
Published: March 2008

A series of 8 cases of elastofibroma is reported, and the clinical, pathological and imaging features and different therapeutic modalities are reviewed. On this basis, we suggest an algorithm for the diagnosis and treatment of elastofibroma. Briefly, marginal excision is the treatment of choice in symptomatic patients, while followup appears to be a good solution in asymptomatic ones.
Bridging Science and Practice in Violence Prevention: Addressing Ten Key Challenges
Authors: Saul Janet , Duffy Jennifer , Noonan Rita , Lubell Keri , Wandersman Abraham , Flaspohler Paul , Stillman Lindsey , Blachman Morris , Dunville Richard
Published: March 2008

This article illustrates ideas for bridging science and practice generated during the Division of Violence Prevention's (DVP) dissemination/implementation planning process. The difficulty of moving what is known about what works into broader use is near universal, and this planning process pushed us to look beyond the common explanations (e.g., providers were resistant/unwilling to change practice) and think about the multiple layers and systems involved. As part of this planning process, the Interactive Systems Framework for Dissemination and Implementation (ISF) was developed and then applied to the fields of child maltreatment and youth violence prevention. Challenges for each of the three systems in the ISF are discussed as well as and action and research ideas to address the challenges. Also described are actions taken by DVP in response to the planning process to illustrate how a funder can use the ISF to bridge science and practice.
Change in Pain Severity With Open Label Venlafaxine Use in Patients With a Depressive Symptomatology: An Observational Study in Primary Care
Authors: Begré Stefan , Traber Martin , Gerber Martin , von Känel Roland
Published: March 2008

Purpose.

Venlafaxine has shown benefit in the treatment of depression and pain. Worldwide data are extensively lacking investigating the outcome of chronic pain patients with depressive symptoms treated by venlafaxine in the primary care setting. This observational study aimed to elucidate the efficacy of venlafaxine and its prescription by Swiss primary care physicians and psychiatrists in patients with chronic pain and depressive symptomatology.

Subjects and methods.

We studied 505 patients with depressive symptoms suffering from chronic pain in a prospective naturalistic Swiss community based observational trial with venlafaxine in primary care. These patients have been treated with venlafaxine by 122 physicians, namely psychiatrists, general practitioners, and internists.

Results.

On average, patients were treated with 143 ± 75 mg (0–450 mg) venlafaxine daily for a follow-up of three months. Venlafaxine proved to be beneficial in the treatment of both depressive symptoms and chronic pain.

Discussion.

Although side effects were absent in most patients, physicians might have frequently omitted satisfactory response rate of depression by underdosing venlafaxine. Our results reflect the complexity in the treatment of chronic pain in patients with depressive symptoms in primary care.

Conclusion.

Further randomized dose-finding studies are needed to learn more about the appropriate dosage in treating depression and comorbid pain with venlafaxine.