bluuebunny/crossref_metadata_2025 huggingface dataset:
Anatomical reconstructions of pediatric airways from endoscopic images: A pilot study of the accuracy of quantitative endoscopy
Authors: Meisner Eric M. , Hager Gregory D. , Ishman Stacey L. , Brown David , Tunkel David E. , Ishii Masaru
Published: May 2013

Objectives/Hypothesis

To evaluate the accuracy of three‐dimensional (3D) airway reconstructions obtained using quantitative endoscopy (QE). We developed this novel technique to reconstruct precise 3D representations of airway geometries from endoscopic video streams. This method, based on machine vision methodologies, uses a post‐processing step of the standard videos obtained during routine laryngoscopy and bronchoscopy. We hypothesize that this method is precise and will generate assessment of airway size and shape similar to those obtained using computed tomography (CT).

Study Design

This study was approved by the institutional review board (IRB). We analyzed video sequences from pediatric patients receiving rigid bronchoscopy.

Methods

We generated 3D scaled airway models of the subglottis, trachea, and carina using QE. These models were compared to 3D airway models generated from CT. We used the CT data as the gold standard measure of airway size, and used a mixed linear model to estimate the average error in cross‐sectional area and effective diameter for QE.

Results

The average error in cross sectional area (area sliced perpendicular to the long axis of the airway) was 7.7 mm2 (variance 33.447 mm4). The average error in effective diameter was 0.38775 mm (variance 2.45 mm2), approximately 9% error.

Conclusion

Our pilot study suggests that QE can be used to generate precise 3D reconstructions of airways. This technique is atraumatic, does not require ionizing radiation, and integrates easily into standard airway assessment protocols. We conjecture that this technology will be useful for staging airway disease and assessing surgical outcomes.

Level of Evidence

N/A. Laryngoscope, 123:2880–2887, 2013
Imaging of subcutaneous microcirculation vascular network by double correlation Optical Coherence Tomography
Authors: Doronin Alexander , Meglinski Igor
Published: May 2013

Spatial distribution of superficial blood vessels in human skin in vivo has been observed by using the double correlation Optical Coherence Tomography (OCT). To remove background noise, reduce the artifacts associated with patient motions and to increase the overall quality of the experimental OCT images an adaptive Wiener filtering technique has been employed. Fourier domain correlation has been subsequently applied to enhance spatial resolution of images of vascular network in human skin in vivo. Image processing has been performed on Graphics Processing Units (GPUs) utilizing Compute Unified Device Architecture (CUDA) framework in the frequency‐domain. This approach allows carrying out image processing in parallel significantly speeding up the computations. The presented results show that the double correlation method permits obtaining 2D/3D OCT images of subcutaneous microcirculation vascular network and its spatial distribution within the human skin with higher spatial resolution compare to the other OCT correlation‐based techniques developed earlier.
Blends of Plasticized Polyvinyl Butyral and Polyvinyl Chloride: Morphology Analysis in View of Recycling
Authors: Bendaoud Amine , Carrot Christian , Charbonnier Jordan , Pillon Caroline
Published: May 2013

The morphology development of blends of plasticized polyvinyl butyral (PVB) with plasticized polyvinyl chloride (PVC) is studied to obtain a droplet‐in‐matrix morphology. Such blends can be used for recycling wastes of plasticized PVB in PVC for flooring because migration of the plasticizer of PVB towards the surface is reduced. Model systems of PVC plasticized with diisodecyl phthalate (DIDP) and of PVB plasticized with dibutyl sebecate (DBS) are used as representatives of common compositions. The percolation threshold of the PVB phase occurs at 22 vol% of plasticized PVB. The morphology results of an equilibrium between break‐up and coalescence. The dependence of the characteristic dimension upon the volume fraction is described by a power‐law with exponent 1.5 slightly larger than the theoretical value.
UV‐Cured Epoxy–Zno Composites: Preparation and Characterization
Authors: Sangermano Marco , Sordo Federica , Giovine Mario , Kortaberria Galder
Published: May 2013

Epoxy–ZnO composites are prepared via UV‐induced cationic polymerization. Complete unsoluble materials are achieved after 10 min of irradiation. Thermal analyses shows an increase of Tg in the presence of the ZnO attributable to a strong hindrance effect of the polymer chain mobility. Electrical characterization of the cured materials shows the decrease of the real part of permittivity with frequency. Both permittivity and AC conductivity values increase with nanofiller content, especially for the highest contents. This is described as typical behavior of nanocomposites made from polymers and fillers with higher permittivity and conductivity values, in accordance with previous data reported in literature for similar composites.
Fabrication and Characterisation of Microgel/Polymer Composite Microfibres
Authors: Kehren Dominic , Pich Andrij
Published: May 2013

In this work microgel‐PVA composite fibres are prepared by means of an electrospinning process using aqueous solutions of poly(vinyl alcohol) (PVA) and poly(N‐vinylcaprolactam)‐based microgels. The optimal parameters are defined to fabricate homogenous composite fibres in which the microgels are embedded into a PVA matrix. It is demonstrated that the fibres can be physically and chemically crosslinked. The fibre morphology is visualised and its properties investigated by differential scanning calorimetry, DSC, thermo‐gravimetric analysis, TGA, and isothermal moisture sorption analysis. The results show that the thermo‐sensitive properties of the microgels are retained inside the fibres and that the degree of swelling and the moisture sorption kinetics can be tuned by changing the temperature.
Poly(2‐vinylpyridine)‐block ‐Poly(ϵ‐caprolactone) Single Crystals in Micellar Solution
Authors: Su Mei , Huang Haiying , Ma Xiaojing , Wang Qian , Su Zhaohui
Published: May 2013

Self‐assembly of poly(2‐vinylpyridine)‐block‐poly(ϵ‐caprolactone) (P2VP‐b‐PCL) diblock copolymer in the presence of a selective solvent is investigated by transmission electron microscopy and atomic force microscopy. Addition of water into a P2VP‐b‐PCL solution in N,N‐dimethylformamide at 20 °C produces elongated truncated lozenge shaped single crystals of uniform size and shape in large quantities. The single crystals are composed of PCL single‐crystal layer sandwiched between two P2VP layers tethered on the top and bottom basal surfaces. The formation of the single crystals is found to depend on the temperature. These findings provide a facile approach to the preparation of uniform single crystals in large quantities.

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Methyl nutrients, DNA methylation, and cardiovascular disease
Authors: Glier Melissa B. , Green Timothy J. , Devlin Angela M.
Published: May 2013

Diet plays an important role in the development and prevention of cardiovascular disease (CVD), but the molecular mechanisms are not fully understood. DNA methylation has been implicated as an underlying molecular mechanism that may account for the effect of dietary factors on the development and prevention of CVD. DNA methylation is an epigenetic process that provides “marks” in the genome by which genes are set to be transcriptionally activated or silenced. Epigenomic marks are heritable but are also responsive to environmental shifts, such as changes in nutritional status, and are especially vulnerable during development. S‐adenosylmethionine is the methyl group donor for DNA methylation and several nutrients are required for the production of S‐adenosylmethionine. These methyl nutrients include vitamins (folate, riboflavin, vitamin B12, vitamin B6, choline) and amino acids (methionine, cysteine, serine, glycine). As such, imbalances in the metabolism of these nutrients have the potential to affect DNA methylation. The focus of this review is to provide an overview on the current understanding of the relationship between methyl nutrient status and DNA methylation patterns and the potential role of this interaction in CVD pathology.
Phenethyl isothiocyanate inhibits androgen receptor‐regulated transcriptional activity in prostate cancer cells through suppressing PCAF
Authors: Yu Chunguang , Gong Ai‐Yu , Chen Dongqing , Solelo Leon Daniel , Young Charles YF , Chen Xian‐Ming
Published: May 2013

Scope

Androgen receptor (AR) signaling is critical for all aspects of prostate growth and tumorigenesis. The glucosinolate‐derived phenethyl isothiocyanate (PEITC) has recently been demonstrated to reduce the risk of prostate cancer (PCa) and inhibit PCa cell growth. We previously reported that p300/CBP‐associated factor (PCAF), a co‐regulator for AR, is upregulated in PCa cells through suppression of the mir‐17 gene. Here, we assessed the effects of PEITC on PCAF expression and AR‐regulated transcriptional activity in PCa cells.

Methods and results

Using AR‐responsive LNCaP cells, we observed the inhibitory effects of PEITC on the dihydrotestosterone‐stimulated AR transcriptional activity and cell growth of PCa cells. Interestingly, overexpression of PCAF attenuated the inhibitory effects of PEITC on dihydrotestosterone‐stimulated AR transcriptional activity. Expression of PCAF was upregulated in PCa cells through suppression of miR‐17. PEITC treatment significantly decreased PCAF expression and promoted transcription of miR‐17 in LNCaP cells. Functional inhibition of miR‐17 attenuated the suppression of PCAF in cells treated by PEITC.

Conclusion

Our results indicate that PEITC inhibits AR‐regulated transcriptional activity and cell growth of PCa cells through miR‐17‐mediated suppression of PCAF, suggesting a new mechanism by which PEITC modulates PCa cell growth.
Human sperm CRISP2 is released from the acrosome during the acrosome reaction and re‐associates at the equatorial segment
Authors: Nimlamool Wutigri , Bean Barry S. , Lowe‐Krentz Linda J.
Published: May 2013

Sperm CRISP2 has been proposed to be involved in sperm–egg fusion. After the acrosome reaction, it appears at the equatorial segment (EqS) of human sperm; the mechanism underlying the appearance of CRISP2 at the EqS remains unknown, though. Here, we provide evidence showing the re‐association of sperm acrosomal CRISP2 at the EqS during the acrosome reaction. Results showed that F‐actin is not involved in the relocalization of CRISP2. We found that basic, but not acidic, conditions can solubilize CRISP2 from sperm cells, suggesting that CRISP2 is a component of the acrosome and that it is released from the acrosome during the acrosome reaction. Purified, biotinylated human sperm acrosomal CRISP2 binds to the EqS of acrosome‐reacted sperm in a dose‐dependent manner, revealing that CRISP2 detected at the EqS of acrosome‐reacted sperm comes from the population stored in the acrosome. The association of CRISP2 at the EqS is very strong, and does not depend on ionic interactions or intermolecular disulfide bonds. Interestingly, the restriction of CRISP2 at the EqS was diminished when EGTA was present in the media, indicating that Ca2+ is required for maintaining CRISP2 at the EqS. This study supports the possibility that CRISP2 may help modify the EqS membrane to make this domain fusion‐competent. Mol. Reprod. Dev. 80: 488–502, 2013. © 2013 Wiley Periodicals, Inc.
Indexed distribution analysis for improved significance testing of spatially heterogeneous parameter maps: Application to dynamic contrast‐enhanced MRI biomarkers
Authors: Rose Chris J. , O'Connor James P. B. , Cootes Tim F. , Taylor Chris J. , Jayson Gordon C. , Parker Geoff J. M. , Waterton John C.
Published: May 2013

Purpose

To develop significance testing methodology applicable to spatially heterogeneous parametric maps of biophysical and physiological measurements arising from imaging studies.

Theory

Heterogeneity can confound statistical analyses. Indexed distribution analysis (IDA) transforms a reference distribution, establishing correspondences across parameter maps to which significance tests are applied.

Methods

Well‐controlled simulated and clinical Ktrans data from a dynamic contrast‐enhanced magnetic resonance imaging study of bevacizumab were analyzed using conventional significance tests of parameter averages, histogram analysis, and IDA. Repeated pretreatment scans provided negative control; a post treatment scan provided positive control.

Results

Histogram analysis was insensitive to simulated and known effects. Simulation: conventional analysis identified treatment effect (P ≈ 5 × 10−4) and direction, but underestimated magnitude (relative error 67–81%); IDA identified treatment effect (P = 0.001), magnitude, direction, and spatial extent (100% accuracy). Bevacizumab: conventional analysis was sensitive to treatment effect (P = 0.01; 95% confidence interval on Ktrans decrease: 23–37%); IDA was sensitive to treatment effect (P < 0.05; Ktrans decrease approximately 25%), inferred its spatial extent to be 94–96%, and inferred that Ktrans decrease is independent of baseline value, an inference that conventional and histogram analyses cannot make.

Conclusions

In the presence of heterogeneity, IDA can accurately infer the magnitude, direction, and spatial extent of between samples of parametric maps, which can be visualized spatially with respect to the original parameter maps. Magn Reson Med 71:1299–1311, 2014. © 2013 Wiley Periodicals, Inc.
Simple anthropometrics are more correlated with health variables than are estimates of body composition in Yup'ik people
Authors: Bray Maria , Pomeroy Jeremy , Knowler William C. , Bersamin Andrea , Hopkins Scarlett , Brage S⊘ren , Stanhope Kimber , Havel Peter J. , Boyer Bert B.
Published: May 2013

Objectives

To (1) evaluate the relationships between several indices of obesity with obesity‐related risk factors; (2) compare the accuracy of body composition estimates derived from anthropometry and bioimpedance analysis (BIA) to estimates of body composition assessed by doubly‐labeled water (DLW); and (3) establish equations for estimating fat mass (FM), fat‐free mass (FFM), and percent body fat (PBF) in Yup'ik people.

Design and Methods

Participants included 1,056 adult Yup'ik people from 11 communities in Southwestern Alaska. In a sub‐study of 30 participants, we developed population‐specific linear regression models for estimating FM, FFM, and PBF from anthropometrics, age, sex, and BIA against criterion measures derived from total body water assessed with DLW. These models were then used with the population cohort and we analyzed the relationships between obesity indices and several health‐related and disease status variables: (1) fasting plasma lipids, (2) glucose, (3) HbA1c, (4) adiponectin, (5) blood pressure, (6) diabetes (DM), and (7) cerebrocoronary vascular disease (CCVD) which includes stroke and heart disease.

Results

The best model for estimating FM in the sub‐study used only three variables—sex, waist circumference (WC), and hip circumference and had multiple R2 = 0.9730. FFM and PBF were calculated from FM and body weight.

Conclusion

WC and other anthropometrics were more highly correlated with a number of obesity‐related risk factors than were direct estimates of body composition. Body composition in Yup'ik people can be accurately estimated from simple anthropometrics.
Global Partnerships for International Fieldwork in Occupational Therapy: Reflection and Innovation
Authors: Cameron Debra , Cockburn Lynn , Nixon Stephanie , Parnes Penny , Garcia Lesley , Leotaud Jacqui , MacPherson Kristina , Mashaka Peter A. , Mlay Ruth , Wango Julius , Williams Trish
Published: May 2013

International fieldwork placements (IFPs) have become very popular among healthcare students including those in occupational therapy programmes. There are many potential benefits that can accrue to the students; however, there are critiques of international placements especially for students going to underserviced areas. The purpose of this paper is to provide a case study/model programme description that critically reflects on six partnerships in three underserviced countries that provide IFPs to students from one Canadian university. The personal opinions of each partner were collected verbally, by email and by a qualitative review of the past 10 years of partnership interaction. Some of the benefits reported by partners include the development of an increased number of sustainable long‐term quality placements, orientation materials, student supports and the involvement of university faculty in research and capacity building projects in partner countries. A number of challenges were identified including the need for an expanded formal agreement, more bilateral feedback and examination of supervision models. This paper examines a limited number of partnerships with only one Canadian partner. Direct input of students is not utilized, although feedback given to co‐authors by students is reflected. More research is needed on perspectives of partners in IFPs, impact of IFPs on clinical practice in student's home countries, impact of IFPS on underserviced areas and effective strategies for debriefing. Copyright © 2013 John Wiley & Sons, Ltd.
Preparation and characterization of PPy doped with different anionic surfactants
Authors: Li Mei , Li Wenguang , Liu Jun , Yao Jinshui
Published: May 2013

Polypyrrole (PPy) was successfully prepared by chemical oxidation in various anionic surfactant solvents and an interesting regulation of the molar ratio of the oxidant and the monomer was firstly discovered which was closely related to the conductivity of the PPy when the molar ratio of the anionic surfactant to the monomer was 0.3. The value of conductivity reached its maximum when the molar ratio of the oxidant and the monomer was 1.1. A series of testing results including scanning electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Four‐Point Probes Resistivity Measurement System showed that the morphology and conducting characteristic of obtained PPy were greatly influenced by the anionic surfactant. The doping level and the degree of the structural order of counterions in the polymer chains influence the conductivity of the obtained doped PPy. POLYM. ENG. SCI., 53:2465–2469, 2013. © 2013 Society of Plastics Engineers
MULTIPLE DIMENSIONS OF PARENTAL INVOLVEMENT AND ITS LINKS TO YOUNG ADOLESCENT SELF‐EVALUATION AND ACADEMIC ACHIEVEMENT
Authors: Kaplan Toren Nurit
Published: May 2013

Drawing on early research on parental involvement and its effect on children's school functioning, it was hypothesized in this study that parents’ educational involvement is positively related to two indicators of school functioning: academic self‐competence and academic achievement. However, in light of research on the distinction between parents’ home‐ and school‐based educational involvement in terms of their different provisions of parents’ school‐related support, this study examined the relationship between each of these two bases and two adolescent outcomes: self‐evaluation (consisting of global self‐worth and scholastic self‐evaluation) and school‐reported academic achievement. Analyses using structural equation modeling (SEM) on data collected from 397 (187 girls) Israeli seventh‐graders (first year of junior high school) confirm the distinction between home‐ and school‐based parental involvement and their different links to adolescent outcomes. SEM analyses carried out separately for girls and boys showed positive links between home‐based parental involvement for girls and parent's volunteering for boys and global self‐worth. This analysis also showed direct negative links between school‐based parental involvement and academic achievement for boys. The discussion addresses these differences and their implication for the school experiences of young adolescents in the wake of the transition to junior high school.
Gas Temperature Effect on Reactive Species Generation from the Atmospheric Pressure Air Plasma
Authors: Kim Ho Young , Kang Sung Kil , Kwon Hyoung Cheol , Lee Hyun Woo , Lee Jae Koo
Published: May 2013

Using surface type air atmospheric pressure plasma, we investigated the amount of ozone and other reactive species generation with variations of the surface temperature of an electrode through an optical emission spectrum and a tube type gas detector. Reduced version of global model (GM) was employed to complement these experimental observations. The results of the model matched well with the experimental data. The amount of ozone generated from the surface type air plasma device was dramatically reduced with increasing temperature. Atomic oxygen (O) and nitric oxide (NO) radicals, which are important agents for biomedical applications, proportionally increased with increasing temperature. We also elucidated the dominant reaction related to the generation or loss of these radicals based on temperature variation through our GM.
The highly dynamic oligomeric structure of bradavidin II is unique among avidin proteins
Authors: Leppiniemi Jenni , Meir Amit , Kähkönen Niklas , Kukkurainen Sampo , Määttä Juha A. , Ojanen Markus , Jänis Janne , Kulomaa Markku S. , Livnah Oded , Hytönen Vesa P.
Published: May 2013

Bradavidin II is a biotin‐binding protein from Bradyrhizobium japonicum that resembles chicken avidin and bacterial streptavidin. A biophysical characterization was carried out using dynamic light scattering, native mass spectrometry, differential scanning calorimetry, and isothermal titration calorimetry combined with structural characterization using X‐ray crystallography. These observations revealed that bradavidin II differs from canonical homotetrameric avidin protein family members in its quaternary structure. In contrast with the other avidins, bradavidin II appears to have a dynamic (transient) oligomeric state in solution. It is monomeric at low protein concentrations but forms higher oligomeric assemblies at higher concentrations. The crystal structure of bradavidin II revealed an important role for Phe42 in shielding the bound ligand from surrounding water molecules, thus functionally replacing the L7,8 loop essential for tight ligand binding in avidin and streptavidin. This bradavidin II characterization opens new avenues for oligomerization‐independent biotin‐binding protein development.
Physics and paintings – a note on the cover
Authors: Bucklow Spike
Published: May 2013

A basic understanding of the physical composition of historic works of art, such as Old Master paintings, is essential for their long‐term preservation. Such a broad understanding has largely been obtained over the last fifty years. However, a more sophisticated understanding of paintings' complex structures can also provide evidence of their modes of production. Such research can offer insights into historic technologies, of which surviving paintings are some of the finest products. This paper is an overview that uses a few examples to illustrate the sophisticated scientific and technological infrastructures that supported the creation of European art up to the 17th century. It briefly indicates how knowledge about material behaviour was transmitted and then lost. It treats great paintings as engineered structures made to the most exacting specifications and suggests that the physical nature of artworks offers researchers significant challenges.
Sparse inverse kernel Gaussian Process regression
Authors: Das Kamalika , Srivastava Ashok N.
Published: May 2013

Regression problems on massive data sets are ubiquitous in many application domains including the Internet, earth and space sciences, and finances. Gaussian Process regression (GPR) is a popular technique for modeling the input–output relations of a set of variables under the assumption that the weight vector has a Gaussian prior. However, it is challenging to apply GPR to large data sets since prediction based on the learned model requires inversion of an ordernkernel matrix. Approximate solutions for sparse Gaussian Processes have been proposed for sparse problems. However, in almost all cases, these solution techniques are agnostic to the input domain and do not preserve the similarity structure in the data. As a result, although these solutions sometimes provide excellent accuracy, the models do not have interpretability. Such interpretable sparsity patterns are very important for many applications. We propose a new technique for sparse GPR that allows us to compute a parsimonious model while preserving the interpretability of the sparsity structure in the data. We discuss how the inverse kernel matrix used in Gaussian Process prediction gives valuable domain information and then adapt the inverse covariance estimation from Gaussian graphical models to estimate the Gaussian kernel. We solve the optimization problem using the alternating direction method of multipliers that is amenable to parallel computation. We compare the performance of this algorithm to different existing methods for sparse covariance regression in terms of both speed and accuracy. We demonstrate the performance of our method in terms of accuracy, scalability, and interpretability on two different satellite data sets from the climate domain. © 2013 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 6: 205–220, 2013
Secure transmission for big data based on nested sampling and coprime sampling with spectrum efficiency
Authors: Chen Junjie , Liang Qilian , Wang Jie
Published: May 2013

Big data presents critical requirements for security in data collection and transmission of selected data through a communication network. This paper presents a new secure transmission for big data based on nested sparse sampling and coprime sampling. With nested sampling and coprime sampling, besides the advantage of higher spectrum efficiency, big data could also achieve higher power spectral density for binary frequency shift keying (BFSK) signal. When the sampling spacing pairs are big enough, the spectrum of BFSK signal performs like frequency hopping. This property has great advantage in the security of big data collection and transmission using FH/BFSK, as it could achieve low error probability. With the same multitone interfering signal added to FH/BFSK, the error probability becomes much lower using nested sampling and coprime sampling compared with the original FH/BFSK signal. This proves that both nested sampling and coprime sampling could be used in big data transmission to resist interference, while guaranteeing the transmission performance. Copyright © 2013 John Wiley & Sons, Ltd.
A Bayesian approach to strengthen inference for case‐control studies with multiple error‐prone exposure assessments
Authors: Zhang Jing , Cole Stephen R. , Richardson David B. , Chu Haitao
Published: May 2013

In case‐control studies, exposure assessments are almost always error‐prone. In the absence of a gold standard, two or more assessment approaches are often used to classify people with respect to exposure. Each imperfect assessment tool may lead to misclassification of exposure assignment; the exposure misclassification may be differential with respect to case status or not; and, the errors in exposure classification under the different approaches may be independent (conditional upon the true exposure status) or not. Although methods have been proposed to study diagnostic accuracy in the absence of a gold standard, these methods are infrequently used in case‐control studies to correct exposure misclassification that is simultaneously differential and dependent. In this paper, we proposed a Bayesian method to estimate the measurement‐error corrected exposure‐disease association, accounting for both differential and dependent misclassification. The performance of the proposed method is investigated using simulations, which show that the proposed approach works well, as well as an application to a case‐control study assessing the association between asbestos exposure and mesothelioma. Copyright © 2013 John Wiley & Sons, Ltd.
Photosensitizer–Gold Nanorod Composite for Targeted Multimodal Therapy
Authors: Wang Jian , You Mingxu , Zhu Guizhi , Shukoor Mohammed Ibrahim , Chen Zhuo , Zhao Zilong , Altman Meghan B. , Yuan Quan , Zhu Zhi , Chen Yan , Huang Cheng Zhi , Tan Weihong
Published: May 2013

In this work, a DNA inter‐strand replacement strategy for therapeutic activity is successfully designed for multimodal therapy. In this multimodal therapy, chlorin e6 (Ce6) photosensitizer molecules are used for photodynamic therapy (PDT), while aptamer‐AuNRs, are used for selective binding to target cancer cells and for photothermal therapy (PTT) with near infrared laser irradiation. Aptamer Sgc8, which specifically targets leukemia T cells, is conjugated to an AuNR by a thiol‐Au covalent bond and then hybridized with a Ce6‐labeled photosensitizer/reporter to form a DNA double helix. When target cancer cells are absent, Ce6 is quenched and shows no PDT effect. However, when target cancer cells are present, the aptamer changes structure to release Ce6 to produce singlet oxygen for PDT upon light irradiation. Importantly, by combining photosensitizer and photothermal agents, PTT/PDT dual therapy supplies a more effective therapeutic outcome than either therapeutic modality alone.
Formation of Heteroepitaxy in Different Shapes of Au–CdSe Metal–Semiconductor Hybrid Nanostructures
Authors: Haldar Krishna Kanta , Pradhan Narayan , Patra Amitava
Published: May 2013

Formation of heteroepitaxy and designing different‐shaped heterostructured nanomaterials of metal and semiconductor in solution remains a frontier area of research. However, it is evident that the synthesis of such materials is not straightforward and needs a selective approach to retain both metal and semiconductor identities in the reaction system during heterostructure formation. Herein, the epitaxial growth of semiconductor CdSe on selected facets of metal Au seeds is reported and different shapes (flower, tetrapod, and core/shell) hetero‐nanostructures are designed. These results are achieved by controlling the reaction parameters, and by changing the sequence and timing for introduction of different reactant precursors. Direct evidence of the formation of heteroepitaxy between {111} facets of Au and (0001) of wurtzite CdSe is observed during the formation of these three heterostructures. The mechanism of the evolution of these hetero‐nanostructures and formation of their heteroepitaxy with the planes having minimum lattice mismatch are also discussed. This shape‐control growth mechanism in hetero‐nanostructures should be helpful to provide more information for establishing the fundamental study of heteroepitaxial growth for designing new nanomaterials. Such metal–semiconductor nanostructures may have great potential for nonlinear optical properties, in photovoltaic devices, and as chemical sensors.
An E3‐14.7K Peptide that Promotes Microtubules‐Mediated Transport of Plasmid DNA Increases Polyplexes Transfection Efficiency
Authors: Pigeon Lucie , Gonçalves Cristine , Gosset David , Pichon Chantal , Midoux Patrick
Published: May 2013

Chemical vectors as cationic polymers and cationic lipids are promising alternatives to viral vectors for gene therapy. Beside endosome escape and nuclear import, plasmid DNA (pDNA) migration in the cytosol toward the nuclear envelope is also regarded as a limiting step for efficient DNA transfection with non‐viral vectors. Here, the interaction between E3‐14.7K and FIP‐1 to favor migration of pDNA along microtubules is exploited. E3‐14.7K is an early protein of human adenoviruses that interacts via FIP‐1 (Fourteen.7K Interacting Protein 1) protein with the light‐chain components of the human microtubule motor protein dynein (TCTEL1). This peptide is conjugated with pDNA and mediates interaction of pDNA in vitro with isolated microtubules as well as with microtubules in cellulo. Videomicroscopy and tracking treatment of images clearly demonstrate that P79‐98/pDNA conjugate exhibits a linear transport with large amplitude along microtubules upon 2 h transfection with polyplexes whereas control pDNA conjugate exhibits small non‐directional movements in the cytoplasm. Remarkably, P79‐98/peGFP polyplexes enhance by a factor 2.5 (up to 76%) the number of transfected cells. The results demonstrate, for the first time, that the transfection efficiency of polyplexes can be drastically increased when the microtubules migration of pDNA is facilitated by a peptide allowing pDNA docking to TCTEL1. This is a real breakthrough in the non viral gene delivery field that opens hope to build artificial viruses.
Organic Field‐Effect Transistor Memory Devices Using Discrete Ferritin Nanoparticle‐Based Gate Dielectrics
Authors: Kim Beom Joon , Ko Yongmin , Cho Jeong Ho , Cho Jinhan
Published: May 2013

Organic field‐effect transistor (OFET) memory devices made using highly stable iron‐storage protein nanoparticle (NP) multilayers and pentacene semiconductor materials are introduced. These transistor memory devices have nonvolatile memory properties that cause reversible shifts in the threshold voltage (Vth) as a result of charge trapping and detrapping in the protein NP (i.e., the ferritin NP with a ferrihydrite phosphate core) gate dielectric layers rather than the metallic NP layers employed in conventional OFET memory devices. The protein NP‐based OFET memory devices exhibit good programmable memory properties, namely, large memory window ΔVth (greater than 20 V), a fast switching speed (10 μs), high ON/OFF current ratio (above 104), and good electrical reliability. The memory performance of the devices is significantly enhanced by molecular‐level manipulation of the protein NP layers, and various biomaterials with heme FeIII/FeII redox couples similar to a ferrihydrite phosphate core are also employed as charge storage dielectrics. Furthermore, when these protein NP multilayers are deposited onto poly(ethylene naphthalate) substrates coated with an indium tin oxide gate electrode and a 50‐nm‐thick high‐k Al2O3 gate dielectric layer, the approach is effectively extended to flexible protein transistor memory devices that have good electrical performance within a range of low operating voltages (<10 V) and reliable mechanical bending stability.
Abi3bp Is a Multifunctional Autocrine/Paracrine Factor that Regulates Mesenchymal Stem Cell Biology
Authors: Hodgkinson Conrad P. , Naidoo Vinogran , Patti Karl G. , Gomez Jose A. , Schmeckpeper Jeffrey , Zhang Zhiping , Davis Bryce , Pratt Richard E. , Mirotsou Maria , Dzau Victor J.
Published: May 2013

Mesenchymal stem cells (MSCs) transplanted into injured myocardium promote repair through paracrine mechanisms. We have previously shown that MSCs over-expressing AKT1 (Akt-MSCs) exhibit enhanced properties for cardiac repair. In this study, we investigated the relevance of Abi3bp toward MSC biology. Abi3bp formed extracellular deposits with expression controlled by Akt1 and ubiquitin-mediated degradation. Abi3bp knockdown/knockout stabilized focal adhesions and promoted stress-fiber formation. Furthermore, MSCs from Abi3bp knockout mice displayed severe deficiencies in osteogenic and adipogenic differentiation. Knockout or stable knockdown of Abi3bp increased MSC and Akt-MSC proliferation, promoting S-phase entry via cyclin-d1, ERK1/2, and Src. Upon Abi3bp binding to integrin-β1 Src associated with paxillin which inhibited proliferation. In vivo, Abi3bp knockout increased MSC number and proliferation in bone marrow, lung, and liver. In summary, we have identified a novel extracellular matrix protein necessary for the switch from proliferation to differentiation in MSCs.
Synthesis of Tetrodotoxin, a Classic but Still Fascinating Natural Product
Authors: Nishikawa Toshio , Isobe Minoru
Published: May 2013

Tetrodotoxin, a toxic principle of puffer fish intoxication, is one of the most famous marine natural products due to its densely functionalized structure and potent toxicity. Despite its small molecular size (MW 319 g mol−1), tetrodotoxin has long been well known as a formidable molecule in natural product synthesis. We have devoted more than twenty years to developing synthetic strategies for this molecule, resulting in the preparation of a variety of analogues of tetrodotoxin for biological experiments. This account describes a brief history of tetrodotoxin research and an overview of our synthetic efforts toward tetrodotoxin with the underlying logic and strategy.
A new modified centroid classifier approach for automatic text classification
Authors: Elmarhoumy Mahmoud , Abdel Fattah Mohamed , Suzuki Motoyuki , Ren Fuji
Published: May 2013

To enhance the automatic text classification task, this paper proposes a novel approach for treating the problem of inductive bias incurred by the centroid classifier assumption. This approach is a trainable classifier, which takes into account tfidf as a text feature. The main goal of the proposed approach is to take advantage of the most similar training errors in the classification model for successively updating that model based on a certain threshold. The proposed approach is practical and flexible to implement. The complete performance of the proposed approach is measured at several threshold values on the Reuters‐21578 text categorization collection. Experimental results show that the proposed approach can improve the performance of the centroid classifier better than traditional approaches (traditional centroid classifier, support vector machines, decision trees, Bayes nets, and N Bayes) by 1, 1.2, 4.1, 7.5, and 11%, respectively. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Nonlinear simulation of transverse flow interactions with chemically driven convective mixing in porous media
Authors: Hejazi S. H. , Azaiez J.
Published: May 2013

Buoyancy‐driven hydrodynamic instabilities of a miscible reactive interface in a homogeneous porous medium is examined. A bimolecular chemical reaction (A+B→C) is triggered at the interface between two reactant solutions A and B resulting in a chemical product solution C with different density and the viscosity from those of the reactants. The effects of the chemical reaction and a transverse flow parallel to the initial interface between the reactants are numerically analyzed. It was found that as a result of the transverse flow, fingers with sharp concentration gradients tend to develop and advance fast downward leading to higher rates of chemical production. Furthermore, a detailed analysis of the finger growth and the effects of buoyancy, transverse flow and chemical reaction allowed to reach a physical interpretation of the trends observed. Finally, a special tuning of the transverse velocity is proposed to ensure maximum or minimum chemical production applicable to subsurface flows.
On the elemental composition of PM2.5 in central Cairo, Egypt
Authors: Boman Johan , Shaltout Abdallah A. , Abozied Asmaa M. , Hassan Salwa K.
Published: May 2013

Aerosol particles are among the criteria pollutants identified by many countries because of their effects on human health and the environment. Information about the elemental composition of the aerosol particles is useful for source apportionment and determining the possible negative effects of the particulate air pollution. In this study, fine aerosol particles (PM2.5) were collected over 24 h once a week at roof level at the National Research Center in the center of Cairo, Egypt, between September 2010 and May 2011 using a cyclonic sampler. The site is representative of urban residential areas in the center of this megacity. Elemental determination was performed using an energy dispersive X‐ray fluorescence spectrometer with a Mo secondary target, and the measured concentrations were evaluated using the quantitative X‐ray analysis system/AXIL software package. The concentrations of 16 elements were determined in the collected aerosol samples, although some were generally not present at levels above the method's limit of detection. The concentrations of many of the elements exceeded those in other urban environments. The concentration of Pb was 95 ± 200 ng/m3, well below the Egyptian legal limit of 500 ng/m3. This represents a significant decrease since 1997, when concentrations above 3 µg/m3 were measured. The decrease is due to the banning of Pb in vehicle fuel in 1997 and the movement of Pb smelters from the central part of Cairo in 2002. Analysis of the elemental concentrations revealed seasonal variation in their levels and possible sources of the emissions, and enabled us to estimate their effects on human health. Copyright © 2013 John Wiley & Sons, Ltd.
Enzymatic Demulsification of the Oil‐Rich Emulsion Obtained by Aqueous Extraction of Peanut Seeds
Authors: Zhang Shao Bing , Liu Xiang Jun , Lu Qi Yu , Wang Zi Wei , Zhao Xiang
Published: May 2013

This study details the enzymatic destabilization of the emulsion formed during aqueous extraction of peanut seeds and the quality of the resulting oil. The emulsion was exposed to enzymatic treatment and pH adjustment. The experimental results suggest that the alkaline endopeptidase Mifong®2709 was the most effective demulsifier, while Phospholipase A2 and pH adjustment had little effect on emulsion stability. The demulsifying conditions of Mifong®2709 were optimized by response surface methodology (RSM). The optimal conditions which produced a free oil yield of ~94 % were: 1:1 water‐to‐emulsion ratio, enzyme concentration of 1,600 IU/g of emulsion and 70 min hydrolysis time at 50 °C. We found that these conditions resulted in a positive relationship (R2= 0.9671) between free oil yield and the degree of protein hydrolysis. Increased protease treatment produced a smaller number of oil droplets, but the size of these droplets increased significantly. When compared to demulsified oil products obtained by using thermal treatment, the oil obtained by Mifong®2709 exhibited lower acid and peroxide values, contained more tocopherols and had a longer induction time as determined in the Rancimat test. The high yield and quality of peanut oil obtained by enzymatic treatment makes enzyme demulsification a promising approach to recovering free oil in aqueous extractions of peanuts.
Cell‐penetrating peptides: 20 years later, where do we stand?
Authors: Bechara Chérine , Sagan Sandrine
Published: May 2013

Twenty years ago, the discovery of peptides able to cross cellular membranes launched a novel field in molecular delivery based on these non‐invasive vectors, most commonly called cell‐penetrating peptides (CPPs) or protein transduction domains (PTDs). These peptides were shown to efficiently transport various biologically active molecules inside living cells, and thus are considered promising devices for medical and biotechnological developments. Moreover, CPPs emerged as potential tools to study the prime mechanisms of cellular entry across the plasma membrane. This review is dedicated to CPP fundamentals, with an emphasis on the molecular requirements and mechanism of their entry into eukaryotic cells.
The Evi5 family in cellular physiology and pathology
Authors: Lim Yi Shan , Tang Bor Luen
Published: May 2013

The Ecotropic viral integration site 5 (Evi5) and Evi5‐like (Evi5L) belong to a small subfamily of the Tre‐2/Bub2/Cdc16 (TBC) domain‐containing proteins with enigmatically divergent roles as modulators of cell cycle progression, cytokinesis, and cellular membrane traffic. First recognized as a potential oncogene and a cell cycle regulator, Evi5 acts as a GTPase Activating Protein (GAP) for Rab11 in cytokinesis. On the other hand, its homologue Evi5L has Rab‐GAP activity towards Rab10 as well as Rab23, and has been implicated in primary cilia formation. Recent genetic susceptibility analysis points to Evi5 as an important factor in susceptibility to multiple sclerosis. We discuss below the myriad of cellular functions exhibited by the Evi5 family members, and their associations with disease conditions.
Diabetes mellitus due to the toxic misfolding of proinsulin variants
Authors: Weiss Michael A.
Published: May 2013

Dominant mutations in the human insulin gene can lead to pancreatic β‐cell dysfunction and diabetes mellitus due to toxic folding of a mutant proinsulin. Analogous to a classical mouse model (the Akita mouse), this monogenic syndrome highlights the susceptibility of human β‐cells to endoreticular stress due to protein misfolding and aberrant aggregation. The clinical mutations directly or indirectly perturb native disulfide pairing. Whereas the majority of mutations introduce or remove a cysteine (leading in either case to an unpaired residue), non‐cysteine‐related mutations identify key determinants of folding efficiency. Studies of such mutations suggest that the evolution of insulin has been constrained not only by its structure and function, but also by the susceptibility of its single‐chain precursor to impaired foldability.
Minireview: pH and synaptic transmission
Authors: Sinning Anne , Hübner Christian A.
Published: May 2013

As a general rule a rise in pH increases neuronal activity, whereas it is dampened by a fall of pH. Neuronal activity per se also challenges pH homeostasis by the increase of metabolic acid equivalents. Moreover, the negative membrane potential of neurons promotes the intracellular accumulation of protons. Synaptic key players such as glutamate receptors or voltage‐gated calcium channels show strong pH dependence and effects of pH gradients on synaptic processes are well known. However, the processes and mechanisms that allow controlling the pH in synaptic structures and how these mechanisms contribute to normal synaptic function are only beginning to be resolved.
Predictors and pregnancy outcomes associated with a newborn birth weight of 4000 g or more in Lusaka, Zambia
Authors: Liu Katherine C. , Joseph Jessica A. , Nkole Theresa B. , Kaunda Eugine , Stringer Jeffrey S.A. , Chi Benjamin H. , Stringer Elizabeth M.
Published: May 2013

Objective

To identify predictors and outcomes associated with a birth weight of 4000 g or more in Lusaka, Zambia.

Methods

Data from women who delivered between February 2006 and August 2011 were obtained from electronic perinatal records at 25 public sector facilities in Lusaka. Macrosomia was defined as a birth weight of 4000 g or more and normal birth weight as 2500–3999 g. Maternal and newborn characteristics were analyzed for association with macrosomia.

Results

There were 4717 macrosomic and 187 117 normal birth weight newborns. The strongest predictors of macrosomia were high BMI (adjusted odds ratio [AOR], 2.88; 95% confidence interval [CI], 1.95–4.24), prior macrosomic newborn (AOR, 7.60; 95% CI, 6.81–8.49), and history of diabetes (AOR, 3.09; 95% CI, 1.36–6.98). Macrosomic newborns were at increased risk for cesarean delivery (AOR, 1.63; 95% CI, 1.35–1.96), fresh stillbirth (AOR, 2.24; 95% CI, 1.56–3.21), Apgar score of under 7 at 5 minutes (AOR, 2.03; 95% CI, 1.33–3.11), and neonatal intensive care admission (AOR, 2.07; 95% CI, 1.32–3.23).

Conclusion

Screening for macrosomia should be considered for high‐risk patients in Sub‐Saharan Africa. Institutional delivery at facilities with operating rooms and neonatal intensive care services should be encouraged.