bluuebunny/crossref_metadata_2025 huggingface dataset:
Análise de sobrevivência: teoria e aplicações em saúde
Authors: Carvalho Marilia Sá , Andreozzi Valeska Lima , Codeço Claudia Torres , Campos Dayse Pereira , Barbosa Maria Tereza Serrano , Shimakura Silvia Emiko
Published: February 2014

O livro Análise de Sobrevida ganha nova edição. Agora, porém, ele se chama Análise de Sobrevivência, termo mais utilizado em Portugal, onde o livro vem sendo bastante adotado. Nesta segunda edição, todos os capítulos foram reescritos e alguns foram desdobrados em dois, com atualizações e incorporação de novos temas. Embora tenha uma linguagem acessível, não se trata de uma obra somente introdutória: ela inclui desenvolvimentos bastante recentes, como modelos para tratamento de eventos múltiplos e modelos de efeitos aleatórios. A análise de sobrevivência consiste em técnicas estatísticas empregadas para estudar o tempo até a ocorrência de algum evento de saúde, que pode ser o óbito ou a cura, por exemplo. Esse conjunto de técnicas permite verificar de que forma uma variável – por exemplo, a adesão ao tratamento – influencia o tempo até a falha terapêutica de uma droga. Baseados em problemas e pesquisas reais, os exercícios de modelagem de dados de sobrevivência encontrados no livro utilizam o pacote estatístico R, um software livre
In-situ electron holography of carrier accumulation at SiO2/InGaZnO4 interface
Authors: Ikarashi Nobuyuki , Kaneko Kisyoh , Saitoh Motofumi , Takeda Hiroshi
Published: February 2014

Electron holography cross-sectional observation was used to reveal changes in the charge carrier distribution in an electrode/SiO2/InGaZnO4 stacked structure caused by the electrode voltage application. Direct observation of the carrier distribution at the SiO2/InGaZnO4 interface was enabled by examining the potential distribution around the interface. The observation revealed that the electrode voltage induced accumulation and depletion of the carriers at the interface. The observed response of the carrier distribution to the electrode voltage was reproduced by a simulated response of the carrier distribution at an interface between SiO2 and an n-type semiconductor of 10+16 cm−3 doping concentration.
Effect of ultrathin AlN spacer on electronic properties of GaN/SiC heterojunction bipolar transistors
Authors: Miyake Hiroki , Kimoto Tsunenobu , Suda Jun
Published: February 2014

GaN/SiC heterojunction bipolar transistors (HBTs) with an ultrathin AlN spacer layer at the n-GaN/p-SiC emitter junction are proposed for the control of the electronic properties of GaN/SiC heterojunctions. The insertion of an AlN spacer is found to be promising in terms of improving electron injection efficiency owing to the reduced potential barrier (0.54 eV) to electron injection and reduced recombination via interface traps. We also investigated the effect of pre-irradiation of active nitrogen atoms (N*) prior to AlN growth for the control of the electronic properties of GaN/AlN/SiC heterojunctions. We found that the potential barrier was further reduced to 0.46 eV by N* pre-irradiation. The HBT structure was successfully fabricated using our newly developed process featuring ion implantation and Pd ohmic contacts to obtain a low contact resistivity to a p-SiC base at a temperature as low as 600 °C. A fabricated HBT without an AlN layer showed a low current gain (α ∼ 0.001), whereas the GaN/AlN/SiC HBT showed improved current gains of 0.1 in the case of using a 1-nm-thick AlN spacer without N* pre-irradiation and 0.2 in the case of using a 2-nm-thick AlN spacer with N* pre-irradiation.
Quantum confinement effects in doped two-dimensional Si layers: Novel device design for two-dimensional pn-junction structures
Authors: Mizuno Tomohisa , Nakahara Yuhta , Nagata Yuhsuke , Suzuki Yuhya , Aoki Takashi , Sameshima Toshiyuki
Published: February 2014

We have experimentally studied the impurity dopant atom effects on band structure modulation (BSM) and phonon confinement effects (PCEs) in a two-dimensional (2D) Si layer. By the photoluminescence (PL) method, the effect of the dopant atom on the bandgap (E
G) of 2D-Si is found to be very small. However, the E
G narrowing effects of n+ 2D-Si are much smaller than those of conventional 3D n+-Si, which is characteristic of 2D-Si. On the other hand, Raman spectroscopy shows that the PCEs are completely independent of the phosphorous dopant density of n+ 2D-Si. Using the experimental BSM of 2D-Si, we introduce a device design for pn junction structures in 2D-Si for future complementary metal oxide semiconductor (CMOS) devices, to suppress the built-in potential increase of the pn junction, in spite of the E
G expansion in the 2D-Si channel region.
Crystal direction dependence of quantum confinement effects of two-dimensional Si layers fabricated on silicon-on-quartz substrates: modulation of phonon spectra and energy band structures
Authors: Mizuno Tomohisa , Nagata Yuhsuke , Suzuki Yuhya , Nakahara Yuhta , Nagamine Yoshiki , Saita Kengo , Aoki Takashi , Sameshima Toshiyuki
Published: February 2014

We experimentally studied the crystal direction dependence of phonon confinement effects (PCEs) and bandgap (E
G) modulation of a two-dimensional (2D) Si layer fabricated on (100) silicon-on-quartz (SOQ) wafers without a handle Si substrate. For the first time, by polarization Raman spectroscopy, in the case of Raman intensity spectra in the asymmetrical broadening region owing to the PCEs in the 2D Si layer, we demonstrated that the incident laser polarization direction dependence of the Raman intensity deviates from the Raman selection rule. However, a photoluminescence (PL) method shows that the E
G expansion is isotropic in the 2D Si layer. On the other hand, the reflectivity of the 2D Si layer in UV region is also modulated. The reflectivity property modulation is possibly attributable to the energy band modulation in the 2D Si layer.
Channel length scaling limits of III–V channel MOSFETs governed by source–drain direct tunneling
Authors: Koba Shunsuke , Ohmori Masaki , Maegawa Yōsuke , Tsuchiya Hideaki , Kamakura Yoshinari , Mori Nobuya , Ogawa Matsuto
Published: February 2014

The difference in the impact of source–drain (SD) direct tunneling in In0.53Ga0.47As and InP metal–oxide–semiconductor field-effect transistors (MOSFETs) was investigated by a quantum Wigner Monte Carlo simulation. It was found that the subthreshold current increase due to SD direct tunneling is more marked in In0.53Ga0.47As MOSFETs owing to their lower effective mass. In addition, the critical channel length at which a drastic increase in subthreshold current occurs owing to SD direct tunneling was found to be about 20 nm for both In0.53Ga0.47As and InP MOSFETs. Since this value is significantly larger than that for Si MOSFETs, SD direct tunneling can be a major obstacle in downscaling III–V MOSFETs into L
ch < 20 nm. Hence, to go beyond the end of the roadmap, we will need a selection of materials to suppress SD direct tunneling.
Structural characterization of polycrystalline Ge thin films on insulators formed by diffusion-enhanced Al-induced layer exchange
Authors: Numata Ryohei , Toko Kaoru , Oya Naoki , Usami Noritaka , Suemasu Takashi
Published: February 2014

The low-temperature formation of the polycrystalline Ge thin film on an insulating substrate is investigated to develop advanced Ge-based devices onto plastic substrates. We propose a growth promotion technique in Al-induced crystallization (AIC) of amorphous Ge: the modulation of the interlayer between the Ge and Al layers for enhancing the diffusion rate of Ge atoms during annealing. By substituting a conventional AlO
x
interlayer with a GeO
x
interlayer, the growth temperature is significantly reduced from 325 to 200 °C, probably due to the difference of the diffusion coefficient of Ge in the interlayers. The electron backscatter diffraction measurement reveals that the grain size and the crystal orientation strongly depend on the annealing temperature. The 200 °C annealed sample yields a preferentially (111)-oriented Ge layer with large grains (average diameter: 57 µm). Therefore, a large-grained, orientation-controlled Ge layer is simultaneously achieved on an insulating substrate at a low temperature of 200 °C using the diffusion-enhanced AIC technique.
Fine patterning method for silver nanoparticle electrodes using differential hydrophobic and hydrophilic surface properties
Authors: Sugano Ryo , Takeda Yasunori , Kobayashi Yu , Fukuda Kenjiro , Kumaki Daisuke , Tokito Shizuo
Published: February 2014

Using a simple spin-coating process, we have demonstrated a fine patterning method for silver nanoparticle ink by combining hydrophobic and hydrophilic substrate surface properties. The hydrophobic/hydrophilic treated areas were precisely formed on a glass substrate by employing a hydrophobic photoresist and a hydrophilic polymer with a conventional photolithographic patterning process. Using this technique, fine silver electrodes with spaces of 5 µm were successfully formed. We applied this method to the short-channel source/drain electrodes in organic thin-film transistor (TFT) devices and succeeded in fabricating a TFT electrode array with a resolution of 100 ppi. The short-channel pentacene TFT with silver nanoparticle electrodes showed good electrical characteristics with high yields and no hysteresis.
Evolution of slip surface roughness through shear
Authors: Davidesko Guy , Sagy Amir , Hatzor Yossef H.
Published: February 2014

A significant part of displacement in fault zones occurs along discrete shear surfaces. The evolution of fault surface topography is studied here in direct shear laboratory experiments. Matching tensile fracture surfaces were sheared under imposed constant normal stress and sliding velocity. The roughness evolution was analyzed using measurements of surface topography before and after slip. We show that shearing reduces the initial surface roughness at all measurement scales. At all wavelengths, the roughness ratio between initial and final roughness increases as a function of the slip distance. For a given test, the roughness ratio increases with wavelength up to a few millimeters, beyond which the ratio becomes wavelength independent. At this region the roughness measured after slip follows a power law similar to that of the initial tensile fracture surface. We interpret this geometrical evolution as a consequence of the deformation stage of interlocked asperities which is followed by shear‐induced dilation.
The quasi‐electrostatic mode of chorus waves and electron nonlinear acceleration
Authors: Agapitov O. V. , Artemyev A. V. , Mourenas D. , Krasnoselskikh V. , Bonnell J. , Contel O. Le , Cully C. M. , Angelopoulos V.
Published: February 2014

Selected Time History of Events and Macroscale Interactions During Substorms observations at medium latitudes of highly oblique and high‐amplitude chorus waves are presented and analyzed. The presence of such very intense waves is expected to have important consequences on electron energization in the magnetosphere. An analytical model is therefore developed to evaluate the efficiency of the trapping and acceleration of energetic electrons via Landau resonance with such nearly electrostatic chorus waves. Test‐particle simulations are then performed to illustrate the conclusions derived from the analytical model, using parameter values consistent with observations. It is shown that the energy gain can be much larger than the initial particle energy for 10 keV electrons, and it is further demonstrated that this energy gain is weakly dependent on the density variation along field lines.
Hiyama cross‐coupling reaction catalyzed by a palladium salt of 1‐benzyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane chloride under microwave irradiation
Authors: Hajipour Abdol R. , Rafiee Fatemeh , Najafi Narges
Published: February 2014

An efficient catalytic system using 1‐benzyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane chloride ((BeDABCO)2Pd2Cl6) was developed for the Hiyama cross‐coupling reaction of various aryl halides with triethoxy(phenyl)silane. The substituted biaryls were produced in excellent yields in short reaction times using a catalytic amount of this catalyst in NMP at 100 °C. Copyright © 2014 John Wiley & Sons, Ltd.
Green conditions for the Suzuki reaction using microwave irradiation and a new HNT‐supported ionic liquid‐like phase (HNT‐SILLP) catalyst
Authors: Massaro Marina , Riela Serena , Lazzara Giuseppe , Gruttadauria Michelangelo , Milioto Stefana , Noto Renato
Published: February 2014

A new catalytic system based on modified halloysite nanotubes was employed in the Suzuki reaction under microwave irradiation. A set of solvents, times and bases was screened and the best experimental conditions were obtained when the reactions were carried out for 10 min in water–ethanol at 120 °C in presence of K2CO3 as base. Good recyclability was observed. The new catalytic system was employed using either 1 mol% or 0.1 mol%. The palladium catalyst displayed good activity, allowing the synthesis of several biphenyl compounds in high yield working with only 0.1 mol% palladium loading. The application of microwave irradiation decreased the reaction time and also improved conversion with respect to traditional heating. Copyright © 2014 John Wiley & Sons, Ltd.
Prospecting for New Questions: Integrating Geophysics to Define Anthropological Research Objectives and Inform Excavation Strategies at Monumental Sites
Authors: Horsley Timothy , Wright Alice , Barrier Casey
Published: February 2014

Geophysical data have the potential to significantly contribute to archaeological research projects when effectively integrated with more traditional methods. Although pre‐existing archaeological questions about a site may be answered using geophysical methods, beginning an investigation with an extensive geophysical survey can assist in understanding the function and archaeological potential of a site, and may even transform preconceptions about the type and spatial organisation of features that are present. In this way, these prospection tools not only accurately locate and map features to allow recovery of cultural material for identification and dating, we argue that they can go much further, allowing us to prospect for new and appropriate archaeological and anthropological research questions. Such an approach is best realised when geophysical and traditional archaeologists work together to define new objectives and strategies to address them, and by maintaining this collaboration to allow continual feedback between geophysical and archaeological data. A flexible research design is therefore essential in order to allow the methodologies to adapt to the site, the results, and the questions being posed. This methodology is demonstrated through two case studies from mound sites in southeast USA: the transitional Mississippian Washausen site in Illinois; and the Middle Woodland Garden Creek site in North Carolina. In both cases, integrating geophysical methods throughout the archaeological investigations has resulted in multiple phases of generating and addressing new research objectives. Although clearly beneficial at these two mound sites in southeast USA, this interdisciplinary approach has obvious implications well beyond these temporal and geographical areas. Copyright © 2014 John Wiley & Sons, Ltd.
Dosimetric study on eye's exposure to wide band radio frequency electromagnetic fields: Variability by the ocular axial length
Authors: Li Congsheng , Chen Qinghua , Xie Yi , Wu Tongning
Published: February 2014

This paper evaluates the variability of specific absorption rate (SAR) in the human eye. This variability results from changes in ocular axial length (OAL), which is common in many ophthalmologic and vision abnormalities, including myopia. A generic eye model was reconstructed according to published data. The feasibility of using the generic model in numerical research of electromagnetic fields (EMF) was demonstrated by means of comparative simulations with eye models reconstructed from magnetic resonance (MR) scans. Free‐form deformation (FFD) was used to deform the OAL of the generic eye model. Thus, 64 deformed eyes were created and were categorized according to the OAL increase. The finite‐difference time‐domain (FDTD) method was applied in the simulations. The results revealed that changing the OAL does not increase EMF absorption in the eyes or the eye tissues. No additional induced temperature rise was produced by the changes of OAL. The results also indicated that the non‐pathological increment of the OAL, which is inevitable during the childhood, does not increase the SAR in the eyes. Bioelectromagnetics. 35:324–336, 2014. © 2014 Wiley Periodicals, Inc.
BDNF Met66 modulates the cumulative effect of psychosocial childhood adversities on major depression in adolescents
Authors: Cruz‐Fuentes Carlos S. , Benjet Corina , Martínez‐Levy Gabriela A. , Pérez‐Molina Amado , Briones‐Velasco Magdalena , Suárez‐González Jesús
Published: February 2014

Background

The interplay among lifetime adversities and the genetic background has been previously examined on a variety of measures of depression; however, only few studies have focused on major depression disorder (MDD) in adolescence.

Methods

Using clinical data and DNA samples from mouthwash gathered from an epidemiological study on the prevalence of mental disorders in youths between 12 and 17 years old, we tested the statistical interaction between a set of psychosocial adversities experienced during childhood (CAs) with two common polymorphisms in the brain‐derived neurotrophic factor (BDNF) (Val66Met) and SLC6A4 (L/S) genes on the probability of suffering MDD in adolescence.

Results

Genotype or allele frequencies for both polymorphisms were similar between groups of comparison (MDD N = 246; controls N = 270). The CAs factors: Abuse, neglect, and family dysfunctions; parental maladjustment, parental death, and to have experienced a life‐threatening physical illness were predictors of clinical depression in adolescents. Remarkably, the cumulative number of psychosocial adversities was distinctly associated with an increase in the prevalence of depression but only in those Val/Val BDNF individuals; while the possession of at least a copy of the BDNF Met allele (i.e., Met +) was statistically linked with a “refractory” or resilient phenotype to the noticeable influence of CAs.

Conclusion

Liability or resilience to develop MDD in adolescence is dependent of a complex interplay between particular environmental exposures and a set of plasticity genes including BDNF. A better understanding of these factors is important for developing better prevention and early intervention measures.
The Struggle for Web eQuality by Persons with Cognitive Disabilities
Authors: Blanck Peter
Published: February 2014

This article is based on the book eQuality: The Struggle for Web Accessibility by Persons with Cognitive Disabilities (2014, Cambridge University Press). It contends that the rights of individuals with cognitive disabilities to equal access to web content are not only protected under law, but may also be implemented and supported by current user‐based, semantic and cloud technologies. Consistent with the Americans with Disabilities Act and the U.N. Convention on the Rights of Persons with Disabilities, web content equality is defined through functional, rather than disability‐specific, approaches and techniques to enable personalization and customized usage across online functions. Legal challenges brought forward by individuals with cognitive and other disabilities illustrate the barriers still faced by individuals with disabilities to web equality as well as some of the solutions to and outcomes of these challenges. In closing, a view for the full and equal enjoyment of web content, which considers technology, financial benefits, and the role of advocacy and regulations, is discussed. Copyright © 2014 John Wiley & Sons, Ltd.
A molecular targeting against nuclear factor‐κB, as a chemotherapeutic approach for human malignant mesothelioma
Authors: Nishikawa Sho , Tanaka Akane , Matsuda Akira , Oida Kumiko , Jang Hyosun , Jung Kyungsook , Amagai Yosuke , Ahn Ginae , Okamoto Noriko , Ishizaka Saori , Matsuda Hiroshi
Published: February 2014

Chronic inflammation due to the absorption of asbestos is an important cause of mesothelioma. Although the increased prevalence of mesothelioma is a serious problem, the development of effective chemotherapeutic agents remains incomplete. As the nuclear factor‐κB (NF‐κB) pathway contributes to malignant transformation of various types of cells, we explored NF‐κB activity in three different pathological types of malignant mesothelioma cells, and evaluated the therapeutic potential of a recently reported NF‐κB inhibitor, IMD‐0354. NF‐κB was constantly activated in MSTO‐211H, NCI‐H28, and NCI‐H2052 cells, and the proliferation of these cell lines was inhibited by IMD‐0354. D‐type cyclins were effectively suppressed in mixed tissue type MSTO‐211H, leading to cell cycle arrest at sub G1/G1 phase. IMD‐0354 reduced cyclin D3 in both epithelial tissue type NCI‐H28 and sarcomatoid tissue type NCI‐H2052. In a sphere formation assay, IMD‐0354 effectively decreased the number and diameter of MSTO‐211H spheres. Preincubation of MSTO‐211H cells with IMD‐0354 delayed tumor formation in transplanted immunodeficient mice. Furthermore, administration of IMD‐0354 markedly rescued the survival rate of mice that received intrathoracic injections of MSTO‐211H cells. These results indicate that a targeted drug against NF‐κB might have therapeutic efficacy in the treatment of human malignant mesothelioma.
Gamma Knife radiosurgery to four or more brain metastases in patients without prior intracranial radiation or surgery
Authors: Ojerholm Eric , Lee John Y. K. , Kolker James , Lustig Robert , Dorsey Jay F. , Alonso‐Basanta Michelle
Published: February 2014

Data on stereotactic radiosurgery (SRS) for four or more metastases are limited. Existing studies are confounded by significant proportions of patients receiving prior whole‐brain radiation therapy (WBRT) or concurrent WBRT with SRS. Furthermore, published results disagree about the impact of tumor volume on overall survival. A retrospective review identified 38 patients without prior intracranial radiation or surgery who received Gamma Knife (GK) as sole treatment to ≥4 brain metastases in a single session. Twenty‐eight cases with follow‐up imaging were analyzed for intracranial progression. Prognostic factors were examined by univariate (log‐rank test) and multivariate (Cox proportional hazards model) analyses. Common primary tumors were non‐small cell lung (45%), melanoma (37%), and breast (8%). Cases were recursive partitioning analysis class II (94%) or III (6%). Patients harbored a median five tumors (range 4–12) with median total tumor volume of 1.2 cc. A median dose of 21 Gy was prescribed to the 50% isodose line. Patients survived a median 6.7 months from GK. Local treatment failure occurred in one case (4%) and distant failure in 22 (79%). On multivariate analysis, total tumor volume ≥3 cc was significantly associated with distant failure and worsened overall survival (P = 0.042 and 0.040). Fourteen patients (37%) underwent salvage WBRT at a median 10.3 months from GK and seven patients received repeat GK. GK as sole initial treatment for four or more simultaneous metastases spares some patients WBRT and delays it for others. Increased total tumor volume (≥3 cc) is significantly associated with worsened overall survival.
Working through challenges of subclavian, innominate, and aortic arch regions during transradial approach
Authors: Patel Tejas , Shah Sanjay , Pancholy Samir , Deora Surender , Prajapati Kiran , Coppola John , Gilchrist Ian C.
Published: February 2014

Objectives

The aim of this review is to discuss different methods of working through subclavian, innominate, and aortic arch anatomical challenges to increase the success rate of transradial approach (TRA).

Background

Anatomical challenges in the subclavian, innominate, and aortic arch regions are important reasons for failure of TRA. There is limited modern literature describing methods to overcome these challenges and reduce TRA failure.

Methods

A number of primary subclavian, innominate, and aortic arch anatomical challenges are identified and management techniques to overcome them are discussed.

Results

Subclavian, innominate, and aortic arch anatomical challenges can be divided into five subsets, including (1) tortuosity, (2) loop, (3) stenosis, (4) congenital aberrancy, and (5) combined challenges. In depth discussion with supportive examples for the identification and management of these challenges are provided.

Conclusions

Despite lower rates of bleeding and vascular complications as compared to transfemoral approach, the adoption of TRA has been relatively slow in part due to frustration from operator failure during the learning curve. Anatomical challenges of subclavian, innominate, and aortic arch regions play an important role in TRA procedural failure. Using a simple, conceptual, framework to classify the anatomical or functional problem and then applying a logical approach to these challenges can facilitate management and augment operator success rates for TRA. © 2014 Wiley Periodicals, Inc.
Facile one step‐synthesis and characterisation of high aspect ratio core‐shell copper‐polyaniline nanowires
Authors: Sarvi Ali , Gelves Genaro A. , Sundararaj Uttandaraman
Published: February 2014

Metal nanowire/polyaniline core‐shell nanoparticles have significant potential for the development of materials for electrostatical dissipation, electromagnetic interference shields, chemical and biological sensors, charge and hydrogen storage. In this study, the synthesis of novel core‐shell nanostructures of polyaniline‐coated copper nanowires (PANI/CuNWs) is presented. CuNWs of 25 nm in diameter and several microns in length were synthesised using hard template method and were subsequently coated with doped or undoped polyanilines to obtain high aspect ratio core‐shell nanoparticles. SEM, TEM, XPS and electrical conductivity measurements were used to characterise these novel nanomaterials. TEM characterisation showed a smooth polyaniline nanocoating of about 6 nm in thickness over the CuNW surface. The thickness of the coating can be controlled by changing PANI concentration in the solution. XPS results indicate that spontaneous adsorption of polyaniline results from the strong surficial interaction between copper atoms at the nanowire surface and imine groups in the polyaniline backbone.
Gestational cortisol and social play shape development of marmosets' HPA functioning and behavioral responses to stressors
Authors: Mustoe Aaryn C. , Taylor Jack H. , Birnie Andrew K. , Huffman Michelle C. , French Jeffrey A.
Published: February 2014

Both gestational cortisol exposure (GCE) and variability in postnatal environments can shape the later‐life behavioral and endocrine outcomes of the hypothalamic‐pituitary‐adrenal (HPA) axis. We examined the influence of GCE and social play on HPA functioning in developing marmosets. Maternal urinary cortisol samples were collected across pregnancy to determine GCE for 28 marmoset offspring (19 litters). We administered a social separation stressor to offspring at 6, 12, and 18 months of age, during which we collected urinary cortisol samples and behavioral observations. Increased GCE was associated with increased basal cortisol levels and cortisol reactivity, but the strength of this relationship decreased across age. Increased social play was associated with decreased basal cortisol levels and a marginally greater reduction in cortisol reactivity as offspring aged, regardless of offspring GCE. Thus, GCE is associated with HPA functioning, but socially enriching postnatal environments can alter the effects associated with increased fetal exposure to glucocorticoids. © 2014 Wiley Periodicals, Inc. Dev Psychobiol 56: 1229–1243, 2014.
Development of left/right asymmetry in the Caenorhabditis elegans nervous system: From zygote to postmitotic neuron
Authors: Hobert Oliver
Published: February 2014

Despite their gross morphological symmetry, animal nervous systems can perceive and process information in a left/right asymmetric manner. How left/right asymmetric functional features develop in the context of a bilaterally symmetric structure is a very poorly understood problem, in part because very few morphological or molecular correlates of functional asymmetries have been identified so far in vertebrate or invertebrate nervous systems. One of the very few systems in which a molecular correlate for functional lateralization has been uncovered is the taste sensory system of the nematode Caenorhabditis elegans, which is composed of a pair of bilaterally symmetric neurons, ASE left (ASEL) and ASE right (ASER). ASEL and ASER are similar in morphology, connectivity, and molecular composition, but they express distinct members of a putative chemoreceptor gene family and respond in a fundamentally distinct manner to taste cues. Extensive forward and reverse genetic analysis has uncovered a complex gene regulatory network, composed of transcription factors, miRNAs, chromatin regulators, and intercellular signals, that instruct the asymmetric features of these two neurons. In this review, this system is described in detail, drawing a relatively complete picture of asymmetry control in a nervous system. genesis 52:528–543, 2014. © 2014 Wiley Periodicals, Inc.
Nuclear translocation of FGFR1 and FGF2 in pancreatic stellate cells facilitates pancreatic cancer cell invasion
Authors: Coleman Stacey J , Chioni Athina‐Myrto , Ghallab Mohammed , Anderson Rhys K , Lemoine Nicholas R , Kocher Hemant M , Grose Richard P
Published: February 2014

Pancreatic cancer is characterised by desmoplasia, driven by activated pancreatic stellate cells (PSCs). Over‐expression of FGFs and their receptors is a feature of pancreatic cancer and correlates with poor prognosis, but whether their expression impacts on PSCs is unclear. At the invasive front of human pancreatic cancer, FGF2 and FGFR1 localise to the nucleus in activated PSCs but not cancer cells. In vitro, inhibiting FGFR1 and FGF2 in PSCs, using RNAi or chemical inhibition, resulted in significantly reduced cell proliferation, which was not seen in cancer cells. In physiomimetic organotypic co‐cultures, FGFR inhibition prevented PSC as well as cancer cell invasion. FGFR inhibition resulted in cytoplasmic localisation of FGFR1 and FGF2, in contrast to vehicle‐treated conditions where PSCs with nuclear FGFR1 and FGF2 led cancer cells to invade the underlying extra‐cellular matrix. Strikingly, abrogation of nuclear FGFR1 and FGF2 in PSCs abolished cancer cell invasion. These findings suggest a novel therapeutic approach, where preventing nuclear FGF/FGFR mediated proliferation and invasion in PSCs leads to disruption of the tumour microenvironment, preventing pancreatic cancer cell invasion.
Processes for Production of Solar‐Grade Silicon Using Hydrogen Reduction and/or Thermal Decomposition
Authors: Yasuda Kouji , Morita Kazuki , Okabe Toru H.
Published: February 2014

High‐purity Si used for photovoltaic applications, namely, solar‐grade Si (SOG‐Si), is commercially manufactured using the Siemens process. Although the present levels of supply satisfy the demand, there can potentially be a shortage of SOG‐Si in the long term. To overcome the low productivity of the Siemens process, various types of SOG‐Si production/purification processes have been developed as post‐Siemens processes. Some processes are under development as new commercial processes. These processes can be classified into the following three categories: (1) hydrogen reduction and/or thermal decomposition of silane‐based gases in improved Siemens‐based processes, (2) metallothermic reduction of silicon halides by Zn or Al, and (3) upgrading metallurgical‐grade Si by employing metallurgical purification methods. This paper presents a review of various types of SOG‐Si production processes, particularly those based on the hydrogen reduction and/or thermal decomposition of halides and silane‐based gases. These processes are classified on the basis of Si compounds used and the reaction types; further, the features of these processes are also analyzed. Future prospects for the development of new high‐purity Si production process are also presented.
Highly Enriched Nickel‐63 Radionuclide for β‐Voltaic Nuclear Batteries
Authors: Bryskin B. , Pustovalov A. , Tsvetkov L. , Fedorov V. , Kostylev A.
Published: February 2014

The requirements for nickel‐63 (Ni‐63) in β‐voltaic nuclear batteries were analyzed. For commercial use, the degree of Ni‐63 enrichment should in the range of 70–90 % instead of the currently available commercial product (18–20 % enrichment). Such a significant increase in the enrichment level would improve the energy conversion efficiency of the β‐particles by ten times. An industrial scheme for production of highly enriched Ni‐63 is proposed.
Keyhole‐3D phase contrast magnetic resonance angiography: A time‐resolved reconstruction method
Authors: Lee Dong‐Hoon , Hong Cheol‐Pyo , Lee Man‐Woo , Han Bong‐Soo
Published: February 2014

In this study, we studied the keyhole imaging technique to 3D Phase‐contrast magnetic resonance angiography (PC MRA) to improve its temporal resolution. Previously, our research group has already studied the 2D PC MRA combined with keyhole technique, and evaluated the applicability. For keyhole‐3D PC MRA, the keyhole factor was used from 12.5% to 50% of the full k‐space. With keyhole factors above 50%, the images were similar to the original image and the vessels in the brain were well observed. We believe the keyhole‐3D PC MRA will give some advantages for improving the temporal resolution of MR systems.
Performance analysis of EM, SVD, and SVM classifiers in classification of carcinogenic regions of medical images
Authors: Rajaguru Harikumar , Bojan Vinoth Kumar
Published: February 2014

In this article, the performance analysis of Expectation Maximization (EM), Singular Value Decomposition (SVD), and Support Vector Machines (SVM) classifiers for classification of carcinogenic regions from various medical images is carried out. Cancer detection is one of the critical issues where excessive care needs to be taken for better diagnosis. Any classifier needs to detect the cancer with respect to the efficiency in time of detection and performance. Due to these, three classifiers are selected: Expectation Maximization (EM), Singular Value Decomposition (SVD), and Support Vector Machines (SVM). EM classifier performs as the optimizer and SVD classifier performs as the dual class classifier. SVM classifier is used as both optimizer and classifier for multiclass classification procedure and for wide stage cancer detection procedures. The performance analysis of all the three classifiers are analyzed for a group of 100 cancer patients based on the benchmark parameter such as Performance Measures and Quality Metrics. From the experimental results it is evident, that the SVM classifier significantly outperforms other classifiers in the classification of carcinogenic regions of medical images.
Brain tumor severity analysis using modified multi‐texton histogram and hybrid kernel SVM
Authors: Jayachandran A. , Dhanasekaran R.
Published: February 2014

Magnetic resonance image (MRI) segmentation refers to a process of assigning labels to set of pixels or multiple regions. It plays a major role in the field of biomedical applications as it is widely used by the radiologists to segment the medical images input into meaningful regions. In recent years, various brain tumor detection techniques are presented in the literature. In this article, we have developed an approach to brain tumor detection and severity analysis is done using the various measures. The proposed approach comprises of preprocessing, segmentation, feature extraction, and classification. In preprocessing steps, we need to perform skull stripping and then, anisotropic filtering is applied to make image suitable for extracting features. In feature extraction, we have modified the multi‐texton histogram (MTH) technique to improve the feature extraction. In the classification stage, the hybrid kernel is designed and applied to training of support vector machine to perform automatic detection of tumor region in MRI images. For comparison analysis, our proposed approach is compared with the existing works using K‐cross fold validation method. From the results, we can conclude that the modified multi‐texton histogram with non‐linear kernels has shown the accuracy of 86% but the MTH with non‐linear kernels shows the accuracy of 83.8%.
fMRI analysis of excessive binocular disparity on the human brain
Authors: Kim Dongchan , Jung Yong Ju , Han Yeji , Choi Joonsung , Kim Eunwoo , Jeong BumSeok , Ro Yong Man , Park HyunWook
Published: February 2014

The aim of this study is to evaluate brain regions related with excessive binocular disparity that may be linked to stereoscopic visual fatigue. In stereoscopic displays, excessive binocular disparity may generate blurring or double vision in the stereovision and induce unnatural oscillations in accommodation and vergence. These phenomena may lead to visual fatigue and activation (or deactivation) of human brain related with sensory and eye movement functions. A functional magnetic resonance imaging (fMRI) method is used to investigate the effect of excessive binocular disparity on human brain. Subjective assessments of visual fatigue are also conducted with the same stimuli as the fMRI experiment. Based on the subjective assessment results, participants are classified into low‐ and high‐fatigue groups. From the fMRI experiments, the high‐fatigue group showed more activation at the intraparietal sulcus (IPS) than the low‐fatigue group, when viewing an excessive disparity stimulus. The results showed that the excessive binocular disparity stimulus may induce overload to the IPS region, which is related with stereo processing and saccadic eye movement. In addition, it could be possible to use fMRI as an objective measurement method for understanding the stereoscopic visual fatigue when stimuli with excessive binocular disparity are applied.
Does Consumers' Feeling Affect Their Quality of Life? Roles of Consumption Emotion and Its Consequences
Authors: Lee Seonjeong (Ally) , Manthiou Aikaterini , Jeong Miyoung , Tang Liang (Rebecca) , Chiang Lanlung (Luke)
Published: February 2014

Emphasizing the importance of attendees' consumption emotion, this study investigates the impact of festival attendees' consumption emotion on their psychological outcomes such as satisfaction, perceived quality of life and loyalty toward the festival. Structural equation modeling is used to test the dynamics of festival attendees' consumption behavior and its consequences. Results of this study indicate that festival attendees' emotional behavior has a positive relationship with their overall satisfaction, which is identified as a key predictor for their loyalty and quality of life. The study's theoretical contributions and practical implications are discussed in detail along with its limitations. Copyright © 2014 John Wiley & Sons, Ltd.
Significant Reductions in Posttraumatic Stress Symptoms in Congolese Refugees Within 10 days of Transcendental Meditation Practice
Authors: Rees Brian , Travis Fred , Shapiro David , Chant Ruth
Published: February 2014

This follow‐up pilot study tested whether Transcendental Meditation® (TM) practice would significantly reduce symptoms of posttraumatic stress in Congolese refugees within 10 days after instruction. The Posttraumatic Stress Disorder Checklist–Civilian (PCL‐C) was administered to nonmatched waitlist controls from a previous study 3 times over a 90‐day period. Within 8 days of the third baseline measure, 11 refugees were taught TM, then retested 10 days and 30 days after instruction. Average PCL‐C scores dropped 29.9 points from 77.9 to 48.0 in 10 days, then dropped another 12.7 points to 35.3 at 30 days. Effect size at 10 days was high (d = 4.05). There were no adverse events. All participants completed the study and were able to practice TM.
Posttraumatic Stress and Stigma in Active‐Duty Service Members Relate to Lower Likelihood of Seeking Support
Authors: Blais Rebecca K. , Renshaw Keith D. , Jakupcak Matthew
Published: February 2014

Posttraumatic stress disorder (PTSD) is a common mental health concern for returning service members. Social support is a robust predictor of resiliency and recovery from PTSD; however, barriers to seeking support are understudied. PTSD and anticipated enacted stigma from family and friends were explored as correlates of the likelihood of seeking support among 153 Iraq/Afghanistan U.S. service members. Results showed that PTSD (r = −.31, p < .001) and anticipated enacted stigma (r = −.22, p ≤ .01) were negatively associated with likelihood of seeking support. Post hoc analyses showed that only dysphoria (r = −.32, p < .001) was significantly related to the likelihood of seeking support after accounting for anticipated enacted stigma and other PTSD clusters. Implications of these findings and ways to increase likelihood of seeking support are discussed.
Critical point equation on four‐dimensional compact manifolds
Authors: Barros Abdênago , Ribeiro Ernani
Published: February 2014

The aim of this article is to study the space of metrics with constant scalar curvature of volume 1 that satisfies the critical point equation for simplicity CPE metrics. It has been conjectured that every CPE metric must be Einstein. Here, we shall focus our attention for 4‐dimensional half conformally flat manifolds M4. In fact, we shall show that for a nontrivial must be isometric to a sphere and f is some height function on
Molecular targets of isothiocyanates in cancer: Recent advances
Authors: Gupta Parul , Kim Bonglee , Kim Sung‐Hoon , Srivastava Sanjay K.
Published: February 2014

Cancer is a multistep process resulting in uncontrolled cell division. It results from aberrant signaling pathways that lead to uninhibited cell division and growth. Various recent epidemiological studies have indicated that consumption of cruciferous vegetables, such as garden cress, broccoli, etc., reduces the risk of cancer. Isothiocyanates (ITCs) have been identified as major active constituents of cruciferous vegetables. ITCs occur in plants as glucosinolate and can readily be derived by hydrolysis. Numerous mechanistic studies have demonstrated the anticancer effects of ITCs in various cancer types. ITCs suppress tumor growth by generating reactive oxygen species or by inducing cycle arrest leading to apoptosis. Based on the exciting outcomes of preclinical studies, few ITCs have advanced to the clinical phase. Available data from preclinical as well as available clinical studies suggest ITCs to be one of the promising anticancer agents available from natural sources. This is an up‐to‐date exhaustive review on the preventive and therapeutic effects of ITCs in cancer.
Computational simulation of gas separation using nonporous polymeric membranes: Experimental and theoretical studies
Authors: Marjani Azam , Abkhiz Vahid , Fadaei Farzad
Published: February 2014

In this study, preparation and simulation of polydimethylsiloxane (PDMS) membranes for gas separation is carried out. The membranes are synthesized by solution‐casting method via silicon oil as precursor. Gas permeation experiments for single gases of CH4 and N2 were conducted at different feed pressures (2–10 bars). PDMS membrane as a rubbery polymer showed that are more permeable toward more condensable gases, i.e., CH4 compared to N2. It was indicated that increasing feed pressure enhances permeability of CH4 through the membrane slightly, but the permeability of nitrogen was almost constant over enhancement of feed pressure. Moreover, a mathematical model was developed to predict the permeation of gases across PDMS membrane. The model is based on solving conservation equations for gases in the membrane phase. Finite element analysis was utilized for numerical simulation of the governing equations. The simulation results were used to predict the concentration of gases inside the membrane. POLYM. ENG. SCI., 55:54–59, 2015. © 2014 Society of Plastics Engineers
The kinetics of isothermal nicotinamide release from poly(acrylic‐co‐methacrylic acid) loaded xerogel
Authors: Djajic Tatjana , Jovanovic Jelena , Potkonjak Biljana , Adnadjevic Borivoj
Published: February 2014

The isothermal kinetics of in vitro nicotinamide release from poly(acrylic‐co‐methacrylic acid) loaded xerogel into water was evaluated. The isothermal kinetics curves of nicotinamide release from poly(acrylic‐co‐methacrylic acid) xerogel were measured at different temperatures ranging from 296 K to 315 K. It was proven that the kinetics of nicotinamide release from poly(acrylic‐co‐methacrylic acid) xerogel was a kinetically complex process which was neither controlled by the processes of drug diffusion nor with the relaxation of the xerogel. The kinetic of nicotinamide release from poly(acrylic‐co‐methacrylic acid) may be described by the kinetics model of reversible first order chemical reaction and the apparent activation energy have value of Ea,M = 14.1 kJ mol−1 and preexponential factor ln(AM min−1) = 2.3. The rate constants of nicotinamide release (
) and the rate constants of its reversible absorption reaction (
) were calculated and found to fall within the range 0.019 min−1−0.033 min−1 for
and 0.014 min−1−0.016 min−1 for
. The value of activation energy for the nicotinamide releas, Ea.R =21.25 kJ mol−1, is significantly higher than the value for the process of nicotinamide absorption (Ea,A = 2.6 kJ mol−1). The rate of nicotinamide release was predetermined with the rate of nicotinamide molecules distribution between the hydrogel and surrounding solution. POLYM. ENG. SCI., 55:60–69, 2015. © 2014 Society of Plastics Engineers
The morphology, properties, and shape memory behavior of polylactic acid/thermoplastic polyurethane blends
Authors: Jing Xin , Mi Hao‐Yang , Peng Xiang‐Fang , Turng Lih‐Sheng
Published: February 2014

Biodegradable polylactic acid (PLA) was compounded with thermoplastic polyurethane (TPU) by twin‐screw extrusion at weight ratios of 90/10, 80/20, 70/30, and 60/40. The blends were investigated based on their phase morphology, thermal and mechanical properties, and shape memory properties. The tensile results showed that PLA was successfully toughened by TPU. When the TPU content was 40%, the elongation‐at‐break increased to 400%. The SEM morphology showed that TPU was dispersed uniformly in the PLA matrix; DMA and DSC results indicated that the two polymers were immiscible. Most interestingly, it was found that the blends exhibited a shape memory behavior and, unlike most of the existing shape memory polymers (SMPs), the PLA/TPU blends could be deformed at room temperature without an extra heating and cooling step. During the deformation process, TPU acted as a toughening agent that prevented the PLA/TPU blends from breaking; thus, the temporary shape could be kept and internal stress was stored in the blends. Upon heating to above the glass transition temperature of PLA (about 60°C), the deformed parts regained their original shapes quickly along with the release of the stress. POLYM. ENG. SCI., 55:70–80, 2015. © 2014 Society of Plastics Engineers