bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the codon 72 polymorphism of TP53 and human papillomavirus infection in Iranian patients with prostate cancer
Authors: Salehi Zivar , Hadavi Mahvash
Published: July 2012

The TP53 gene is one of the most important tumor suppressor genes controlling DNA transcription and cell regulation. Common polymorphisms in p53 gene may play a role in some cancers. Some studies have reported an association between human papillomavirus (HPV) infections and prostate cancer. The aim of this study was to investigate whether the TP53 codon 72 polymorphism and HPV infection are responsible for susceptibility to prostate cancer in Iranian men. The prostate biopsies were taken during surgery from 68 Iranian prostatic cancer patients, and 85 patients with benign prostate hyperplasia. For genotyping of the p53 polymorphism at codon 72, PCRRFLP methods were used and the PCR products were digested with BstU1. An attempt was also made to detect HPV DNA in benign prostate hyperplasia and prostate cancer specimens. Among cancer cases, the distribution of Arg/Arg, Arg/Pro and Pro/Pro genotypes were 26.5%, 45.4%, and 19.1%, respectively. Among patients with benign prostate hyperplasia, the distribution of Arg/Arg, Arg/Pro, and Pro/Pro genotypes were 27%, 53%, and 20%, respectively. The allele frequencies did not differ significantly between prostate cancer and benign prostate hyperplasia samples. Human papillomavirus was detected only in three patients (4.4%; P = 0.71). The results from this study suggest that the TP53 codon 72 polymorphism and HPV infection do not confer susceptibility to prostate cancer in the Iranian population. Larger population‐based studies are needed to clarify the relation between prostate carcinoma and p53 polymorphism and HPV infection. J. Med. Virol. 84:1423–1427, 2012. © 2012 Wiley Periodicals, Inc.
Toll‐like receptor 3 polymorphism and its association with hepatitis B virus infection in Saudi Arabian patients
Authors: Al‐Qahtani Ahmed , Al‐Ahdal Mohammed , Abdo Ayman , Sanai Faisal , Al‐Anazi Mashael , Khalaf Nisreen , Viswan Nisha A. , Al‐Ashgar Hamad , Al‐Humaidan Hind , Al‐Suwayeh Riham , Hussain Zahid , Alarifi Saud , Al‐Okail Majid , Almajhdi Fahad N.
Published: July 2012

Hepatitis B virus (HBV) is the major causative agent of chronic liver complications including cirrhosis and hepatocellular carcinoma (HCC). Individuals infected with HBV show a wide spectrum of disease manifestations ranging from asymptomatic carriers to HCC. TLR3 is part of the innate immune system that recognizes double‐stranded RNA (dsRNA) and provides early immune response to exogenous antigens. The genetic polymorphisms such as single nucleotide polymorphisms (SNPs) in the TLR3 could be considered as factors for the susceptibility to viral pathogens including HBV. Due to lack of knowledge on the role of TLR3 polymorphisms in HBV infection, this study investigated the distribution of nine SNPs in the TLR3 gene and its association with Saudi Arabian patients infected with HBV. A total of 707 patients and 600 uninfected controls were examined for different parameters including the nine SNPs (rs5743311, rs5743312, rs1879026, rs5743313, rs5743314, rs5743315, rs111611328, rs78726532 and a newly identified SNP located at position 184322913 of chr4). The association analysis confirmed that only one SNP, rs1879026 (G/T), showed a significant difference (P = 0.0480; OR = 0.809, 95% CI = 0.655–0.999) in the distribution between HBV carriers and uninfected controls. While, the rest of the SNPs showed no significant association with regards to HBV infection or in the progression to cirrhosis of the liver and HCC. Furthermore, haplotype analysis revealed that one haplotype GCGA (rs1879026, rs5743313, rs5743314, and rs5743315, respectively), was associated significantly with HBV infection in this population. These findings indicate that genetic variations in the TLR3 gene could affect the outcome of HBV infection among Saudis. J. Med. Virol. 84:1353–1359, 2012. © 2012 Wiley Periodicals, Inc.
Diversity in the VP7 encoding genes of rotavirus strains isolated from adolescent and adult cases of acute gastroenteritis
Authors: Tatte Vaishali S. , Chitambar Shobha D.
Published: July 2012

A study was conducted to examine the diversity in the VP7 genes of rotavirus strains circulating in adolescent and adult cases of acute gastroenteritis during two different time periods, 1993–1996 and 2004–2007. The multiplex RT‐PCR carried out on 131 rotavirus positive fecal specimens detected 65 (49.6%) single and 48 (36.6%) mixed infections of VP7 genotypes that included 43G1 (38.1%), 37G2 (32.7%), 8G3 (7.1%), 15G4 (13.3%), and 10G9 (8.8%) specificities. Sequencing and phylogenetic analysis of the VP7 gene amplicons revealed the presence of G1‐IA (4.7%), G1‐IB (69.8%), and G1‐IC (25.5%) lineages within the G1 strains, G2‐IIb1 (70.3%) and G2‐IIb2 (29.7%) lineages within G2 strains, G3‐3S1 (12.5%) and G3‐3S4 (87.5%) lineages within G3 strains, G4‐Ia (6.7%) and G4‐Ib (93.3%) lineages within G4 strains, and G9‐III lineage within G9 strains. The variability within VP7 genotypes was evident by 1.4–8.0% and 1.3–3.9% amino acid divergence respectively from the prototype strains and between the groups of strains at the two time points. This is the first report describing the phylogenetic analysis of VP7 genes of rotaviruses from adolescent and adult cases of acute gastroenteritis in India. Since adults infected with rotavirus could act as a source of infection and affect the epidemiology of rotaviruses in children, genetic analysis of the rotavirus strains circulating in adults is required. The intragenotypic diversity within VP7 genes demonstrated by the present study highlights the need for constant surveillance of rotavirus infections to understand better the evolution and transmission of group A rotaviruses in the community. J. Med. Virol. 84:1481–1488, 2012. © 2012 Wiley Periodicals, Inc.
Correlation between pretreatment viral sequences and the emergence of lamivudine resistance in hepatitis B virus infection
Authors: Sueki Ryota , Maekawa Shinya , Miura Mika , Kadokura Makoto , Komase Kazuki , Shindo Hiroko , Kanayama Asuka , Ohmori Takako , Shindo Kuniaki , Amemiya Fumitake , Nakayama Yasuhiro , Uetake Tomoyoshi , Inoue Taisuke , Sakamoto Minoru , Enomoto Nobuyuki
Published: July 2012

The emergence of amino acid or nucleotide substitutions leads to lamivudine resistance in hepatitis B virus (HBV) infected patients. The aim of this study was to investigate whether viral sequences help predict the emergence of lamivudine resistance. The study subjects comprised 59 consecutive patients infected with HBV treated with daily therapy of 100 mg lamivudine. Among those, 32 patients with adequate pretreatment serum preservation were investigated for the correlation between viral amino acid substitutions and the appearance of lamivudine resistance with consideration of clinical background by determining dominant HBV full open reading frames. Viral resistance to lamivudine emerged in 28 of 59 patients (47%) in a median period of 2.45 years. Sequence comparisons of HBV genomes between patients who later developed lamivudine resistance and patients who did not revealed the existence of significant differences between the two groups in the pre‐S1 84 (P = 0.042), pre‐S2 1 (P = 0.017) and 22 (P = 0.015), and polymerase tp 95 (P = 0.046), judged by a log‐rank test. Viral sequence analyses revealed the presence of amino acid substitutions in HBV pre‐S1 and pre‐S2 that may be associated with the emergence of lamivudine resistance during chronic HBV infection. J. Med. Virol. 84:1360–1368, 2012. © 2012 Wiley Periodicals, Inc.
Human immunodeficiency virus enhances hepatitis C virus replication by differential regulation of IFN and TGF family genes
Authors: Zhang Xiaozhen , Daucher Marybeth , Baeza Josue , Kim Cheol‐Woo , Russell Rodney , Kottilil Shyamasundaran
Published: July 2012

HIV co‐infection significantly impacts the natural history of hepatitis C virus (HCV) by increasing plasma HCV viral load, accelerating liver disease progression, and reducing rates of HCV clearance. Cytokines play an important role in regulating hepatic inflammation and fibrogenesis during chronic HCV infection, yet the impact of HIV on cytokine expression is unknown. In this study, an HCV continuous infection cell culture system was modified to permit co‐infection with HIV to test the hypothesis that virus‐induced disregulation of immune‐response genes, particularly interferons and TGF‐β, may create a permissive environment for the initial establishment of HIV/HCV co‐infection in the host. CCR5‐expressing Huh‐7.5 hepatoma cells were transduced with human CD4 antigen to allow HIV infection in vitro. Co‐infection of CD4+ Huh‐7.5 cells with HIV and HCV or co‐culture of HIV‐infected CD4+ Huh‐7.5 cells and HCV‐infected Huh‐7.5 cells increased the level of HCV RNA compared to HCV mono‐infection. Quantitative gene expression analysis revealed HIV‐induced up regulation of most tested IFN family genes when compared to HCV or co‐infection. HCV infection induced up regulation of many TGF family genes that were subsequently down‐regulated in the presence of HIV or HIV/HCV. Interestingly, co‐infection resulted in down regulation of several IFN genes and significant up regulation of TGF‐β genes leading to an overall enhancement of HCV replication. These data suggest that HIV infection may influence HCV replication in vitro by increasing levels of HCV RNA, possibly through the differential regulation of endogenous IFN and TGF family genes. J. Med. Virol. 84:1344–1352, 2012. © 2012 Wiley Periodicals, Inc.
Seroprevalence of neutralizing antibodies to human adenovirus type 5 in healthy adults in China
Authors: Yu Bin , Zhou Yan , Wu Hao , Wang Zhen , Zhan Yang , Feng Xiao , Geng Ranshen , Wu Yongge , Kong Wei , Yu Xianghui
Published: July 2012

Human adenoviruses have been used to develop candidate HIV vaccine vectors, but a major obstacle to the use of vectors derived from Ad5 and other common serotypes is the high prevalence of neutralizing antibodies (NAbs) in humans. Prior studies have reported a prevalence of Ad5 between 60% and 70% in Europe and US, and up to 98% in surveyed African and Asian (Thai) tropical countries. However, few studies have reported on the Ad5 prevalence in Chinese populations. In this study, a total of 1,250 healthy adult serum samples from six administratively separate regions of China were screened by high‐throughput luciferase‐based virus neutralization assays. Results showed that overall 72% of healthy adults were Ad5 seropositive, and 46.4% with baseline Ad5 NAb titers of >200 in China. Comprehensive analysis by geographical region and age showed that the seroprevalence of Ad5 in southern China such as Guangxi was higher than that in other regions. Geographical differences and climate were considered as the major factors affecting the titer levels of Ad5 in healthy adults. In addition, no apparent gender and ethnic difference was found in any group classified according to region, age, or NAb titer. The present study may provide useful insights for the future development of Ad5‐based vaccines and gene therapy. J. Med. Virol. 84:1408–1414, 2012. © 2012 Wiley Periodicals, Inc.
Molecular epidemiology of rotavirus and norovirus in Ile‐Ife, Nigeria: High prevalence of G12P[8] rotavirus strains and detection of a rare norovirus genotype
Authors: Japhet Margaret Oluwatoyin , Adesina Olufisayo Adeyemi , Famurewa Oladiran , Svensson Lennart , Nordgren Johan
Published: July 2012

Rotavirus (RV) and norovirus (NoV) are considered the most common causes of viral gastroenteritis in children. In this study, the prevalence of RV and NoV infection in 55 children with diarrhea from the rural community Akinlalu in Southwestern Nigeria was investigated using real‐time PCR assays. The RV and NoV strains were genotyped by PCR and/or sequencing. RV and NoV infections occurred with a prevalence of 34.5% and 25.5% respectively, with predominance in children <1 year. Most infections occurred during the dry season with increasing prevalence of RV as the dry season progressed (October–January). Infections with RV VP6 subgroup (SG) II were more prevalent (27.3%) than SGI (7.3%). Similarly, NoV genogroup II infections were more common (23.6%) than genogroup I (1.8%). Five children out of 55 (9.1%) were co‐infected with both RV and NoV. Notably, G12P[8] was the predominant RV strain (36.8%, n = 7), observed for the first time in Nigeria. The VP7 gene of the G12 strains clustered within lineage III, sharing high nucleotide identity with each other (>99%) indicating introduction in Nigeria from a single donor. Furthermore, a putative novel genotype within genogroup I NoV was detected, which till date has only been reported once in humans. To conclude, a high prevalence of the emerging G12P[8] RV strain was observed for the first time in Nigeria, as well as a putative novel NoV genotype in humans. These results provide new information which can be important for future vaccine evaluations and possible introduction in Nigeria. J. Med. Virol. 84:1489–1496, 2012. © 2012 Wiley Periodicals, Inc.
The prevalence and long term outcome of occult hepatitis B virus infections in community based populations
Authors: Minuk G.Y. , Kowalec K. , Caouette S. , Larke B. , Osiowy C.
Published: July 2012

Features of occult hepatitis B infection in community‐based populations have yet to be described. In this study we documented: (1) the prevalence and demographics, (2) associated serology and viral loads, and (3) clinical outcomes of occult hepatitis B infection in community‐based populations. Hepatitis B surface antigen (HBsAg)‐negative sera collected from three Northern Canadian communities (HBsAg prevalences: 11–12%) in 1983–1985 were tested for HBV‐DNA by nested stage polymerase chain reaction. Of 706 HBsAg negative sera, 9 (1.3%) were HBV‐DNA positive. The median age of occult hepatitis B infected patients at the time of sampling was 9.8 years (range 3.1–50.4 years) and six (67%) were female. Two (22%) individuals were anti‐HBs positive (in the absence of prior vaccination). Viral loads were undetectable in all but two samples (2.40 and 2.86 log10 IU/ml). Only one of the five (20%) patients who were assessed clinically, remained HBV‐DNA positive at 25–30 year follow‐up. There was no clinical, biochemical or radiologic evidence of chronic hepatitis, cirrhosis or hepatocellular carcinoma in these individuals or on review of the charts from the remaining four infected patients. The results of this study suggest that in community‐based populations: (1) occult hepatitis B infection is not as common as HBsAg positive infection, (2) the majority of infected subjects are young females, (3) a minority are anti‐HBs positive, (4) viral loads are either undetectable or low, and (5) in the absence of concurrent liver disease, occult hepatitis B infection does not appear to be associated with long term adverse clinical outcomes. J. Med. Virol. 84:1369–1375, 2012. © 2012 Wiley Periodicals, Inc.
Critical points of Brazil nuts: a beginning for food safety, quality control and Amazon sustainability
Authors: Lima Andriele M , Gonçalves Evonnildo C , Andrade Soraya S , Barbosa Maria SR , Barroso Karla FP , de Sousa Mayara B , Borges Larissa , Vieira Jozé LF , Teixeira Francisco M
Published: July 2012

BACKGROUND: One difficulty of self‐sustainability is the quality assurance of native products. This research was designed to study the risks and critical control points in the collection, handling and marketing of Brazil nuts from native forests and urban fairs in the Brazilian Amazon by characterisation of morphological aspects of fungi and posterior identification by molecular biology and determination of aflatoxins by high‐performance liquid chromatography.

RESULTS: Several corrective actions to improve product quality were found to be necessary in both sites. Growth of fungi was observed in 95% of fragments of Brazil nuts from both sites during the between‐harvest period. Aflatoxin levels indicated that, although fungal growth was observed in both sites, only Brazil nuts from the native forest showed a high risk to human health (total aflatoxin level of 471.69 µg kg−1).

CONCLUSION: This study has shown the main issues related to the process design of Brazil nuts, supporting the necessity for research on new strategies to improve the quality of nuts. Also, the habit of eating Brazil nuts stored throughout the year may represent a risk to farmers. © 2012 Society of Chemical Industry
Enantioseparation of chiral sulfonates by liquid chromatography and subcritical fluid chromatography
Authors: Pell Reinhard , Schuster Georg , Lämmerhofer Michael , Lindner Wolfgang
Published: July 2012

Tert‐butylcarbamoyl‐quinine and ‐quinidine weak anion‐exchange chiral stationary phases (Chiralpak® QN‐AX and QD‐AX) have been applied for the separation of sodium β‐ketosulfonates, such as sodium chalconesulfonates and derivatives thereof. The influence of type and amount of co‐ and counterions on retention and enantioresolution was investigated using polar organic mobile phases. Both columns exhibited remarkable enantiodiscrimination properties for the investigated test solutes, in which the quinidine‐based column showed better enantioselectivity and slightly stronger retention for all analytes compared to the quinine‐derived chiral stationary phase. With an optimized mobile phase (MeOH, 50 mM HOAc, 25 mM NH3), 12 of 13 chiral sulfonates could be baseline separated within 8 min using the quinidine‐derivatized column. Furthermore, subcritical fluid chromatography (SubFC) mode with a CO2‐based mobile phase using a buffered methanolic modifier was compared to HPLC. Generally, SubFC exhibited slightly inferior enantioselectivities and lower elution power but also provided unique baseline resolution for one compound.
Keep in touch: Does spatial overlap correlate with contact rate frequency?
Authors: Robert Karine , Garant Dany , Pelletier Fanie
Published: July 2012

Quantifying animal contact rate is crucial both in fundamental and applied studies to understand the evolution of sociality and predict the spread of infectious diseases. Researchers typically use home‐range overlap among individuals as a proxy of contact rate, assuming a positive correlation. However, very few studies have assessed how the correlation between home‐range overlap and contact rate may vary with ecological context. We used proximity loggers to quantify intraspecific contact rate among raccoons (Procyon lotor) and explored the correlation between contact rate and home‐range overlap in different seasons. We monitored 15 female raccoons that formed 121 dyads during summer 2010 and winter 2011. We compared contact rate with the 5 most common overlap indices: home‐range overlap proportion, home‐range overlap probability, utilization distribution overlap index (UDOI), volume of intersection index, and Bhattacharyya's affinity index. Our results generally supported the contention of a positive and significant correlation between home‐range overlap and intraspecific contact rate in raccoons. The strength of the relationship differed among seasons and indices, being weaker during winter than summer for home‐range overlap proportion and home‐range overlap probability. When contact rates were high, their frequency had stronger correlations with the UDOI and volume of intersection index indices than with the other indices. Our results suggest that the UDOI performs better than other indices, as we obtained a good contact rate–home‐range overlap correlation with this index with animals both aggregated and randomly distributed in space. © 2012 The Wildlife Society.
Allergic fungal otomastoiditis: A case report
Authors: Chen Chiung‐Ming , Chiang Ching‐Wen
Published: July 2012

Allergic mucin is described as thick, peanut butter‐like mucus impacted in the paranasal sinuses of patients with allergic fungal rhinosinusitis. The presence of allergic mucin in the middle ear has never been reported. We encountered a 65‐year‐old female with allergic mucin found impacted in her left middle ear and mastoid cavity during revised tympanoplasty surgery at our institute. Bilateral endoscopic sinus surgery performed 3 months later showed no evidence of fungal infection or allergic mucin in her paranasal sinuses. We report the case herein and propose the term allergic fungal otomastoiditis for this disease entity.
Coherent fiber supercontinuum for biophotonics
Authors: Tu Haohua , Boppart Stephen A.
Published: July 2012

Biophotonics and nonlinear fiber optics have traditionally been two independent fields. Since the discovery of fiber‐based supercontinuum generation in 1999, biophotonics applications employing incoherent light have experienced a large impact from nonlinear fiber optics, primarily because of the access to a wide range of wavelengths and a uniform spatial profile afforded by fiber supercontinuum. However, biophotonics applications employing coherent light have not benefited from the most well‐known techniques of supercontinuum generation for reasons such as poor coherence (or high noise), insufficient controllability, and inadequate portability. Fortunately, a few key techniques involving nonlinear fiber optics and femtosecond laser development have emerged to overcome these critical limitations. Despite their relative independence, these techniques are the focus of this review, because they can be integrated into a low‐cost portable biophotonics source platform. This platform can be shared across many different areas of research in biophotonics, enabling new applications such as point‐of‐care coherent optical biomedical imaging.
Fano resonance in novel plasmonic nanostructures
Authors: Rahmani Mohsen , Luk'yanchuk Boris , Hong Minghui
Published: July 2012

Recently, a large number of experimental and theoretical works have revealed a variety of plasmonic nanostructures with the capabilities of Fano resonance (FR) generation. Among these structures, plasmonic oligomers consisting of packed metallic nanoelements with certain configurations have been of significant interest. Oligomers can exhibit FR independently of the polarization direction based on dipole–dipole antiparallel modes without the need to excite challenging high‐order modes. The purpose of this review article is to provide an overview of recent achievements on FR of plasmonic nanostructures in recent years. Meanwhile, more attention is given to the optical properties of plasmonic oligomers due to the high potential of such structures in optical spectra engineering.
Fabrication of multilayer metamaterials by femtosecond laser‐induced forward‐transfer technique
Authors: Tseng M.L. , Wu P.C. , Sun S. , Chang C.M. , Chen W.T. , Chu C.H. , Chen P.L. , Zhou L. , Huang D.W. , Yen T.J. , Tsai D.P.
Published: July 2012

A novel method based on femtosecond laser‐induced forward transfer for high‐throughput and efficient fabrication of periodic multilayer plasmonic metamaterials is demonstrated. With precisely controlling laser raster path applied on sputtered multilayer thin films, the laser‐ablated materials can be transferred to another substrate leaving the fabricated multilayer structure on the original substrate. Subsequently, three‐dimensional metamaterials can be made by multilayer structuring. Moreover, all the experimental results show that to create such multilayer split resonant rings (SRRs) with uniform profile, the laser fluence should be fine controlled under proper conditions. The optical property of fabricated multilayer SRR array is investigated by optical measurements and finite‐difference time‐domain simulations, showing various resonant modes in the middle‐IR region. The calculated induced current distributions exhibit rich resonance properties of the structures as well. This work markedly extends the laser direct writing technique to a wide application in fabricating complicated metamaterials and plasmonic devices efficiently.
Some characterizations of generalized Hölder spaces
Authors: Kreit Damien , Nicolay Samuel
Published: July 2012

In this paper, we show that the main properties of the usual Hölder spaces can be transposed in the setting of the Hölder spaces defined via admissible sequences. In particular, we give several alternative definitions of these spaces.
Morse homology for the heat flow – Linear theory
Authors: Weber Joa
Published: July 2012

Consider the linear parabolic partial differential equation \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal {D}}_u\xi =0$\end{document} which arises by linearizing the heat flow on the loop space of a Riemannian manifold M. The solutions are vector fields along infinite cylinders u in M. For these solutions we establish regularity and a priori estimates. We show that for nondegenerate asymptotic boundary conditions the solutions decay exponentially in L2 in forward and backward time. In this case \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal {D}}_u$\end{document} viewed as linear operator from the parabolic Sobolev space \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal {W}}^{1,p}$\end{document} to Lp is Fredholm whenever p > 1. We close with an Lp estimate for products of first order terms which is a crucial ingredient in the sequel 13 to prove regularity and the implicit function theorem. The results of the present text are the base to construct in 13 an algebraic chain complex whose homology represents the homology of the loop space.
Surface Functionalization of Poly(ether imide) Membranes with Linear, Methylated Oligoglycerols for Reducing Thrombogenicity
Authors: Lange Maik , Braune Steffen , Luetzow Karola , Richau Klaus , Scharnagl Nico , Weinhart Marie , Neffe Axel T. , Jung Friedrich , Haag Rainer , Lendlein Andreas
Published: July 2012

Materials for biomedical applications are often chosen for their bulk properties. Other requirements such as a hemocompatible surface shall be fulfilled by suitable chemical functionalization. Here we show, that linear, side‐chain methylated oligoglycerols (OGMe) are more stable to oxidation than oligo(ethylene glycol) (OEG). Poly(ether imide) (PEI) membranes functionalized with OGMes perform at least as good as, and partially better than, OEG functionalized PEI membranes in view of protein resistance as well as thrombocyte adhesion and activation. Therefore, OGMes are highly potent surface functionalizing molecules for improving the hemocompatibility of polymers.
Producing a particle‐reinforced AlCuMgMn alloy by means of mechanical alloying
Authors: Siebeck S. , Nestler D. , Wielage B.
Published: July 2012

Ein geeignetes Verfahren zur Herstellung partikelverstärkter Aluminiumwerkstoffe ist das Hochenergie‐Kugelmahlen (HEM) mit anschließender Kompaktierung. Der Schritt HEM hat dabei die Aufgabe harte Partikel in duktilem metallischem Pulver möglichst homogen zu verteilen. Eine andere Anwendung von HEM ist das mechanische Legieren. Der vorliegende Beitrag beschäftigt sich mit der Kombination beider Effekte. Rein metallische Pulver (Al, Cu, Mg, Mn) wurden dazu gemeinsam mit SiC‐Pulver als Verstärkungskomponente bis zu 10 h gemahlen. Die Zusammensetzung der metallischen Pulver entspricht der der Legierung EN AW‐2017 (3,9% Cu, 0,7% Mg, 0,6% Mn). In bisherigen Versuchen wurde diese Legierung in Form von verdüstem Pulver verwendet. Die mikrostrukturellen Vorgänge innerhalb der sich bildenden Pulverteilchen während des Mahlens werden ausführlich mittels Lichtmikroskopie, REM, EDXS und XRD untersucht. Die Ergebnisse zeigen, dass die Herstellung von Verbundpulver in nur einem Schritt möglich ist. Dies erlaubt nicht nur die wirtschaftlichere Herstellung derartiger Pulver, sondern ermöglicht auch die Verwendung von Legierungszusammensetzungen, welche nicht oder nur schwer schmelzmetallurgisch herstellbar sind. Die Herstellung von tailor‐made‐Legierungen bietet sich an.
Gradation extrusion – Severe plastic deformation with defined gradient
Authors: Neugebauer R. , Sterzing A. , Selbmann R. , Zachäus R. , Bergmann M.
Published: July 2012

In Severe Plastic Deformation (SPD) processes usually the whole material volume is subjected to the severe deformation. The generated fine‐grained structure is proposed to be uniformly distributed throughout the component. The resulting physical and mechanical properties have a comparatively even distribution at a homogeneous level. The goal of the presented research work is to generate a defined inhomogeneous structure with advantageous property distributions corresponding to local loads on the component. The new forming technology gradation extrusion has been developed for this purpose. This method is the base for the manufacture of cylindrical parts with a defined gradation of the grain size allowing new local combinations of physical and mechanical properties. The new technology has the potential to produce an ultrafine‐grained structure which can extend up to several mm deep below the surface. This layer is characterized by an increased strength while the inner material with a coarse grained structure has excellent ductility. Such a property combination has a high relevance for many practical applications. The presented technological approach can bridge the gap between methods refining the complete volume and methods of surface refinement only.
FE simulation of coated forming tools for high strength aluminium alloys
Authors: Neugebauer R. , Schmidt G. , Oppermann C. , Wielage B. , Lampke T. , Rupprecht C. , Nehrkorn S.
Published: July 2012

Es wird auf die Notwendigkeit der FE‐Simulation und die dabei anfallenden Arbeitsschritte bei der Optimierung von beschichteten Umformwerkzeugen eingegangen. Nach der auf die konkrete Anwendung abgestimmten Schichtauswahl werden Materialparameter bestimmt und die dabei auftretenden Probleme bei Dünnschichten (Dicke in der Größenordnung von 2 μm) werden diskutiert. Die speziellen Probleme bei der numerischen Lösung der Modelle werden ebenfalls angesprochen. Letztendlich werden Ergebnisse der Simulation erläutert und Modifikationen in Variantenrechnungen untersucht.
On the simulation of multi‐stage forming processes: invariance under change of the reference configuration
Authors: Shutov A. V. , Pfeiffer S. , Ihlemann J.
Published: July 2012

The need to change the reference configuration can naturally appear during the numerical simulation of multi‐stage metal forming processes. In the current work, a refined approach to the consideration of previously induced plastic anisotropy is discussed, which is based on such configuration change. The model of finite strain viscoplasticity proposed by Shutov and Kreißig is considered in this study as a practical tool, suitable to capture the evolution of mechanical properties of material during inelastic deformation. The initial plastic anisotropy can be considered within this model by a special choice of initial conditions imposed on the relevant internal variables. A simple transformation law which is based on the isochoric change of the reference configuration is obtained in the current study. This transformation allows to obtain relevant initial conditions with respect to a new reference configuration. Thus, the initial conditions are formulated using the simulation results from the foregoing loading. The advocated approach is exemplified by the numerical simulation of equal channel angular pressing of cylindrical billets. The plastic anisotropy accumulated during a single ECAP pass is estimated using a series of virtual tension tests. These tests were performed on samples cut from processed billet with their gage lengths in different directions. Finally, the impact of the plastic anisotropy on the rotation of the workpiece within the output channel during ECAP is numerically estimated.
Cost Calculation of tools for manufacturing aluminum‐based lightweight materials using the example of an extrusion recipient
Authors: Götze U. , Morgenstern S. , Schmidt A. , Strehl G. , Zönnchen S.
Published: July 2012

Strangpressen stellt eines der wirtschaftlichsten Umformverfahren für Aluminiumwerkstoffe dar und weist zugleich ein hohes Weiterentwicklungspotenzial für neue Verfahrensvarianten und Anwendungsgebiete auf. Für die konkrete Produktivität des Strangpressens wiederum spielt der Rezipient, als Komponente des Werkzeugsatzes, eine entscheidende Rolle. Um nun die Wirtschaftlichkeit des Verfahrens im spezifischen Anwendungsfall sowie verschiedene Werkzeugkonzepte beurteilen und zudem zielgerichtet Angebotspreise festlegen zu können, ist die Kenntnis der Kosten, die durch die Herstellung und/oder den Einsatz des Rezipienten verursacht werden, erforderlich. Daher wird eine Kalkulationsmethodik benötigt, die in der Lage ist, im Rahmen der Entwicklung und Konstruktion von Rezipienten – bei einer noch schmalen Informationsbasis – eine fundierte und relativ exakte Aussage über die Kostenhöhe zu generieren. Die Entwicklung einer solchen Methodik sowie deren Umsetzung in einem IT‐gestützten Kalkulationstool sind Gegenstand dieses Beitrags.
Influence of anodic oxide coatings on screwing behaviour and susceptibility to stress corrosion cracking of self‐tapping aluminium screws
Authors: Sieber M. , Scharf I. , Härtel M. , Hellmig R. J. , Lampke T.
Published: July 2012

Enhanced use of lightweight materials, namely aluminium and magnesium, requires the application of appropriate production techniques. Self‐tapping screws represent an innovative joining technology. High‐strength aluminium alloys can be used as screw material. Stringent requirements regarding the wear resistance of screw surfaces result from the thread‐forming process. These requirements are met by oxide ceramic conversion layers produced by hard anodizing. Based on application‐oriented testing methods, the influence of hard anodized layers on the screwing behaviour and susceptibility to stress corrosion cracking of high‐strength aluminium screws is examined.
Decision making, impulsivity, and addictions: Do Parkinson's disease patients jump to conclusions?
Authors: Djamshidian Atbin , O'Sullivan Sean S. , Sanotsky Yanosh , Sharman Stephen , Matviyenko Yuriy , Foltynie Thomas , Michalczuk Rosanna , Aviles‐Olmos Iciar , Fedoryshyn Ludmyla , Doherty Karen M. , Filts Yuriy , Selikhova Marianna , Bowden‐Jones Henrietta , Joyce Eileen , Lees Andrew J. , Averbeck Bruno B.
Published: July 2012

Links between impulsive‐compulsive behaviors (ICBs) in treated Parkinson's disease (PD), behavioral addictions, and substance abuse have been postulated, but no direct comparisons have been carried out so far. We directly compared patients with PD with and without ICBs with illicit drug abusers, pathological gamblers, and age‐matched healthy controls using the beads task, a test of reflection impulsivity, and a working memory task. We found that all patients with PD made more impulsive and irrational choices than the control group. PD patients who had an ICB showed similar behavior to illicit substance abusers, whereas patients without ICBs more closely resembled pathological gamblers. In contrast, we found no difference in working memory performance within the PD groups. However, PD patients without ICBs remembered distractors significantly less than all other patients during working memory tests. We were able to correctly classify 96% of the PD patients with respect to whether or not they had an ICB by analyzing three trials of the 80/20 loss condition of the beads task with a negative prediction value of 92.3%, and we propose that this task may prove to be a powerful screening tool to detect an ICB in PD. Our results also suggest that intact cortical processing and less distractibility in PD patients without ICBs may protect them from developing behavioral addictions. © 2012 Movement Disorder Society
Combined use of free jejunum and pectoralis major muscle flap with skin graft for reconstruction after salvage total pharyngolaryngectomy
Authors: Miyamoto Shimpei , Sakuraba Minoru , Nagamatsu Shogo , Kamizono Kenichi , Fujiki Masahide , Hayashi Ryuichi
Published: July 2012

Salvage total pharyngolaryngectomy after failed organ‐preserving therapy often results in composite defects involving the alimentary tract, trachea, and neck skin. This retrospective study examined combined use of the free jejunum flap and the pectoralis major muscle flap with skin graft for such a complex reconstruction. We reviewed 11 patients who underwent free jejunum transfer for alimentary reconstruction and pedicled pectoralis major muscle flap transfer with a skin graft on the muscle for simultaneous neck skin resurfacing after salvage total pharyngolaryngectomy from 2005 through 2010. The operative morbidity rate was 27.3%. No pharyngocutaneous fistula developed in this series. Oral intake could be resumed within 3 weeks after surgery in all patients. Seven of 11 patients had a functional tracheostoma with adequate stomal patency. Combined use of free jejunum and pectoralis major muscle flap with skin graft provided secure wound closure even for complicated cases. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.
Subacute and delayed period microsurgical management of traumatic extremity injuries in pediatric population
Authors: Arslan Hakan , Çinar Can , Bingöl Uǧur Anil , Yücel Osman Akin
Published: July 2012

The purpose of the present report is to evaluate the outcome of subacute and delayed period microsurgical reconstructions of traumatic extremity defects of the pediatric patients. Eighteen free tissue transfers had been performed in 18 patients. Patients ranged in age from 5 to 17 years of age and had a median age of 12.05 years. The time between trauma and free flap transfer varied between 8 and 86 days (mean, 30.8 days). Hospital stay ranged from 8 to 90 days, with a mean stay of 38.7 days. Postoperative complications were seen in 8 of 18 patients (44.4%). Re‐exploration for venous thrombosis was necessary in two patients, and total flap loss occurred in one case. The average follow‐up time was 34 months. One could conclude from our report and the reference literature that the frequently quoted dogma of a definitive defect closure within 7 days may have lost much of its justification. The final results obtained after delayed definitive soft tissue reconstruction compare favorably with results previously reported in the literature from patient groups whose wounds could be closed in the early period within 7 days. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Justification of the Ginzburg–Landau approximation for an instability as it appears for Marangoni convection
Authors: Schneider Guido , Zimmermann Dominik
Published: July 2012

The Ginzburg–Landau equation appears as a universal amplitude equation for spatially extended pattern forming systems close to the first instability. It can be derived via multiple scaling analysis for the Marangoni convection problem that is driven by temperature‐dependent surface tension and is the subject of our interest. In this paper, we prove estimates between this formal approximation and true solutions of a scalar pattern forming model problem showing the same spectral picture as the Marangoni convection problem in case of a thin fluid. The new difficulties come from neutral modes touching the imaginary axis for the wave number k = 0 and from identical group velocities at the critical wave number k = kc and the wave number k = 0. The problem is solved by using the reflection symmetry of the system and by using the fact that the modes concentrate at integer multiples of the critical wave number k = kc. The paper presents a method that is applicable whenever this kind of instability occurs. Copyright © 2012 John Wiley & Sons, Ltd.
An inverse source problem for a two dimensional time fractional diffusion equation with nonlocal boundary conditions
Authors: Kirane Mokhtar , Malik Salman A. , Al‐Gwaiz Mohammed A.
Published: July 2012

We consider the inverse source problem for a time fractional diffusion equation. The unknown source term is independent of the time variable, and the problem is considered in two dimensions. A biorthogonal system of functions consisting of two Riesz bases of the space L2[(0,1) × (0,1)], obtained from eigenfunctions and associated functions of the spectral problem and its adjoint problem, is used to represent the solution of the inverse problem. Using the properties of the biorthogonal system of functions, we show the existence and uniqueness of the solution of the inverse problem and its continuous dependence on the data. Copyright © 2012 John Wiley & Sons, Ltd.
Navigating Motherhood Choices in the context of Rheumatoid Arthritis: Women's Stories
Authors: Meade T. , Sharpe L. , Hallab L. , Aspanell D. , Manolios N.
Published: July 2012

Objective

Planning a family is a complex decision. For women with chronic conditions such as rheumatoid arthritis (RA), there are additional concerns about their own and their baby's health. This qualitative study examined women's experiences of negotiating their family decisions in the context of RA.

Methods

A qualitative study was conducted in 14 women who provided a written account of their motherhood decisions and experiences. Those ‘stories’ were then thematically analysed.

Results

RA was found to affect women's motherhood decisions and experiences. Three key themes were identified for both the process of decision making and the experience of that decision: capacity, uncertainty and acceptance. Only two of the women decided not to have children, while for others the decision centred on changing expectations from the number of children they planned to have, to parenting within the restrictions of their physical abilities.

Conclusion

While many women struggled through the negotiations of their motherhood choices, those who chose to have children reported great joy in that experience. The challenges faced by women with RA contemplating motherhood, however, highlight the need for understanding and support from health professionals and the provision of resources so that women can make informed choices. Copyright © 2012 John Wiley & Sons, Ltd.
Polysialic acid expression is not necessary for motor neuron target selectivity
Authors: Robinson Grant A. , Madison Roger D.
Published: July 2012

Introduction: Recovery after peripheral nerve lesions depends on guiding axons back to their targets. Polysialic acid upregulation by regrowing axons has been proposed recently as necessary for this target selectivity. Methods: We reexamined this proposition using a cross‐reinnervation model whereby axons from obturator motor neurons that do not upregulate polysialic acid regenerated into the distal femoral nerve. Our aim was to assess their target selectivity between pathways to muscle and skin. Results: After simple cross‐repair, obturator motor neurons showed no pathway preference, but the same repair with a shortened skin pathway resulted in selective targeting of these motor neurons to muscle by a polysialic acid–independent mechanism. Conclusion: The intrinsic molecular differences between motor neuron pools can be overcome by manipulation of their access to different peripheral nerve pathways such that obturator motor neurons preferentially project to a terminal nerve branch to muscle despite not upregulating the expression of polysialic acid. Muscle Nerve 47: 364–371, 2013
Long‐term effects of neck irradiation on cardiovascular autonomic function: A study in nasopharyngeal carcinoma patients after radiotherapy
Authors: Huang Chih‐Cheng , Huang Tai‐Lin , Hsu Hsuan‐Chih , Chen Hui‐Chun , Lin Hsin‐Ching , Chien Chih‐Yen , Fang Fu‐Min , Chang Hsueh‐Wen , Tsai Nai‐Wen , Chang Wen‐Neng , Chen Shu‐Fang , Lin Tzu‐Kong , Tan Teng‐Yeow , Chang Chuang‐Rung , Wang Hung‐Chen , Lin Wei‐Che , Lu Cheng‐Hsien
Published: July 2012

Introduction

Baroreflex failure has been reported as a late sequalum of neck radiotherapy. In this study we investigated cardiovascular autonomic function in patients after neck radiotherapy to determine predictive factors associated with outcome.

Methods

Eighty‐nine patients with nasopharyngeal carcinoma were evaluated ≥6 months after radiotherapy for cardiovascular autonomic function and compared with 48 control subjects. Inflammatory markers and carotid intima–media thickness were also assessed.

Results

Autonomic parameters of heart rate response to deep breathing and Valsalva ratio were significantly lower in the patient group. Cardiovascular autonomic impairment was generally mild with relative sparing of the efferent cardiovagal pathway. By univariate and multivariate analyses, the time after radiotherapy and C‐reactive protein level were significantly associated with the degree of cardiovascular autonomic dysfunction.

Conclusions

Radiation‐induced cardiovascular autonomic impairment is a dynamic and progressive process that occurs long after radiotherapy. Chronic inflammation plays a major role in this process. Muscle Nerve 47:344‐350, 2013
Factors associated with night‐time calf muscle cramps: A case–control study
Authors: Hawke Fiona , Chuter Vivienne , Burns Joshua
Published: July 2012

Introduction: Although highly prevalent and painful, night‐time calf muscle cramping is poorly understood, and no treatment has shown consistent efficacy or safety. Methods: One hundred sixty adults were recruited from New South Wales, Australia, including 80 who had night‐time calf cramping at least once per week and 80 age‐ and gender‐matched adults who did not. Participants were assessed using reliable tests of lower limb strength, flexibility, morphometrics, circulation, and sensation, and were questioned about health and lifestyle factors, diet, medications, exercise, symptomatology, sleeping habits, and footwear. Results: Conditional logistic regression identified 3 factors independently associated with night‐time calf muscle cramps: muscle twitching (OR 4.6, 95% CI 1.6–15.5, P = 0.01); lower limb tingling (OR 4.1, 95% CI 1.6–10.3, P = 0.003); and foot dorsiflexion weakness (OR 1.02, 95% CI 1.01–1.03, P = 0.002), which represented other measures of lower limb weakness in the model. Conclusions: Night‐time calf muscle cramps were associated with markers of neurological dysfunction and potential musculoskeletal therapeutic targets. Muscle Nerve 47:339‐343, 2013
Validation of the modified LDIFlare technique: A simple and quick method to assess C‐fiber function
Authors: Vas Prashanth R.J. , Rayman Gerry
Published: July 2012

Introduction

In this study we validated a modified laser Doppler imager method (mLDIf) for assessing C‐fiber function and compared it to the original (oLDIf). Both measure flare size in foot skin after heating, but the mLDIf uses 47°C (vs. 44°C), making it quicker and better suited for clinical use.

Methods

To confirm that mLDIf assesses C‐fiber function, 5 healthy controls (HC) were studied before and after local anesthesia (LA). Reproducibility and comparison with oLDIf was assessed in HC (n = 16). Finally, diabetes subjects with (DN+, n = 10) and without (DN−, n = 16) neuropathy were studied.

Results

LA almost abolished the flare (9.3 ± 3.0 cm2 vs. 1.7 ± 0.3 cm2, P < 0.0001). mLDIf produced larger flares (9.9 ± 3.4 vs. 5.7 ± 2.3 cm2, P < 0.0001), but correlated with oLDIf (r = 0.81, P < 0.001). mLDIf was reduced in DN− (6.8 ± 2.8 vs. HC, P = 0.003), markedly so in DN+ (2.0 ± 1.1 vs. HC and DN−, P < 0.0001).

Conclusion

The mLDIf is a quick, practical method for assessing C‐fiber function in the clinical setting. Muscle Nerve 47:351‐356, 2013