bluuebunny/crossref_metadata_2025 huggingface dataset:
Intraepithelial macrophage infiltration is related to a high number of regulatory T cells and promotes a progressive course of HPV‐induced vulvar neoplasia
Authors: van Esch Edith M.G. , van Poelgeest Mariette I.E. , Trimbos J. Baptist M.Z. , Fleuren Gert Jan , Jordanova Ekaterina S. , van der Burg Sjoerd H.
Published: September 2014

Human papilloma virus (HPV)‐induced usual‐type vulvar intraepithelial neoplasia (uVIN) is infiltrated by myeloid cells but the type and role of these cells is unclear. We used triple immunofluorescent confocal microscopy to locate, identify and quantify myeloid cells based on their staining pattern for CD14, CD33 and CD163 in a cohort of 43 primary and 20 recurrent uVIN lesions, 21 carcinomas and 26 normal vulvar tissues. The progressive course of uVIN is characterized by an increase in both intraepithelial and stromal mature M1 and M2 macrophages. While the M2 macrophages outnumber M1 macrophages in healthy controls and uVIN, they are matched in number by M1 macrophages in cancer. Importantly, uVIN patients with a dense intraepithelial infiltration with mature CD14+ macrophages (irrespective of M1 or M2 type) displayed approximately a six times higher risk to develop a recurrence and a high number of these cells constituted an independent prognostic factor for recurrence. In addition, a dense intraepithelial CD14+ cell infiltration was associated with high numbers of intraepithelial CD4+ Tregs and low numbers of stromal CD8+TIM3+ T cells. Patients with low numbers of intraepithelial CD14+ cells and high numbers of stromal CD8+TIM3+ cells showed the best recurrence‐free survival. These data clearly show the importance of the local immune response in HPV‐induced vulvar neoplasia and may be of help in predicting the prognosis of patients or their response to immunotherapy.
The solvent effect on two competing reaction mechanisms involving hypervalent iodine reagents (λ3‐iodanes): Facing the limit of the stationary quantum chemical approach
Authors: Sala Oliver , Lüthi Hans Peter , Togni Antonio
Published: September 2014

Trifluoromethylation of acetonitrile with 3,3‐dimethyl‐1‐(trifluoromethyl)−1λ3,2‐ benziodoxol is assumed to occur via reductive elimination (RE) of the electrophilic CF3‐ligand and MeCN bound to the hypervalent iodine. Computations in gas phase showed that the reaction might also occur via an SN2 mechanism. There is a substantial solvent effect present for both reaction mechanisms, and their energies of activation are very sensitive toward the solvent model used (implicit, microsolvation, and cluster‐continuum). With polarizable continuum model‐based methods, the SN2 mechanism becomes less favorable. Applying the cluster‐continuum model, using a shell of solvent molecules derived from ab initio molecular dynamics (AIMD) simulations, the gap between the two activation barriers (
) is lowered to a few kcal mol−1 and also shows that the activation entropies (
) and volumes (
) for the two mechanisms differ substantially. A quantitative assessment of
will therefore only be possible using AIMD. A natural bond orbital‐analysis gives further insight into the activation of the CF3‐reagent by protonation. © 2014 Wiley Periodicals, Inc.
Clinical Supervision of Psychotherapy: Essential Ethics Issues for Supervisors and Supervisees
Authors: Barnett Jeffrey E. , Molzon Corey H.
Published: September 2014

Clinical supervision is an essential aspect of every mental health professional's training. The importance of ensuring that supervision is provided competently, ethically, and legally is explained. The elements of the ethical practice of supervision are described and explained. Specific issues addressed include informed consent and the supervision contract, supervisor and supervisee competence, attention to issues of diversity and multicultural competence, boundaries and multiple relationships in the supervision relationship, documentation and record keeping by both supervisor and supervisee, evaluation and feedback, self‐care and the ongoing promotion of wellness, emergency coverage, and the ending of the supervision relationship. Additionally, the role of clinical supervisor as mentor, professional role model, and gatekeeper for the profession are discussed. Specific recommendations are provided for ethically and effectively conducting the supervision relationship and for addressing commonly arising dilemmas that supervisors and supervisees may confront.
Relational Mentoring in Clinical Supervision: The Transformational Supervisor
Authors: Johnson W. Brad , Skinner Cessily J. , Kaslow Nadine J.
Published: September 2014

Effective clinical supervision naturally incorporates many elements of mentoring. In this article, we us the Mentoring Relationship Continuum (MRC) model to frame a discussion of transformational supervision. We define transformational supervision as a rich developmental relationship characterized by increasing relational reciprocity, a greater range of career and psychosocial mentoring functions, and a strong sense of collegiality. As a strong supervisory relationship approaches the transformational end of the MRC, the supervisor offers increasing levels of support, empowerment, authenticity, and reciprocity; over time, the relationship has a more interdependent, egalitarian, and communitarian character. We employ a case example to illustrate excellent transformational supervision.
The Ingredients of Supervisor Failure
Authors: Ladany Nicholas
Published: September 2014

Trainees all too often learn more about how not to conduct supervision than how to conduct supervision effectively. The purpose of this article is to present a conceptualization of the theoretical, empirical, and practical elements of supervisor failures. Specifically, the article attends to the following behaviors that may lead to supervisor failure: (a) denigrate the supervisory relationship; (b) demonstrate multicultural incompetence; (c) become an unethical supermodel; (d) use evaluation instruments that could not pass for an undergraduate thesis; (e) teach your trainee how to diagnose narcissism by example; (f) apply psychotherapy models in supervision as if there is a theoretical or empirical basis; (g) infantalize your trainee; (h) collude with your trainee; (i) make your trainee your surrogate psychotherapist; and (j) go on a date with your trainee. Recommendations for increasing supervisor success and limiting supervisor failure are provided.
Pervaporation catalytic membrane reactor study for the production of ethyl acetate using Zr(SO4)2.4H2O coated chitosan membrane
Authors: Unlu Derya , Hilmioglu Nilufer Durmaz
Published: September 2014

BACKGROUND

A pervaporation catalytic membrane reactor (PVCMR) can contain reaction and separation systems in one unit. This separation technique has attracted increasing attention in recent years due to its low energy requirement, environmentally friendly technology, easy control and scale‐up in integrated systems. The main aim of this present study is to develop a catalytic polymeric composite membrane for application in a PVCMR.

RESULTS

In this study, esterification of acetic acid and ethanol were studied as a model reaction in a batch reactor and in a PVCMR. A composite membrane was prepared by coating chitosan membrane with a thin layer of Zr(SO4)2.4H2O. Tests were carried out to optimize operating conditions such as initial molar ratio, catalyst concentration and temperature. The acetic acid conversion was increased from 22% to 85% using a PVCMR by removal of water from the reaction mixture in the optimum operating conditions. Under the tested conditions, a molar ratio of reactants 1:1, catalyst concentration 0.25 g L‐1 and temperature 70 °C were found to be optimum conditions for separation.

CONCLUSION

The PVCMR exhibited higher performances than the batch reactor in the esterification of ethanol and acetic acid. The PVCMR can be used efficiently for other esterification reactions. © 2014 Society of Chemical Industry
Asymptomatic “placental prolapse” with cervical funneling in a patient with complete placenta previa
Authors: Adekola Henry , Lam‐Rachlin Jennifer , Bronshtein Elena , Abramowicz Jacques S.
Published: September 2014

We describe the transvaginal sonographic findings in a patient with complete placenta previa and increased risk of preterm birth owing to a prior history of mid‐trimester pregnancy loss in whom we observed a short cervix and prolapse of the placenta and fetal membranes into the endocervical canal. We believe that this could lead to antepartum hemorrhage and mandate close observation when diagnosed. We introduced the term “placental prolapse” to describe our finding. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound, 43:122–125, 2015
Classification of Planning and Violent Behaviours in Serial Homicide: A Cross‐National Comparison Between South Africa and the US
Authors: Sorochinski Marina , Salfati C. Gabrielle , Labuschagne Gerard N.
Published: September 2014

Recent literature suggests that different ‘styles’ of homicide will most appropriately be reflected in the different types of behaviours committed by offenders during the crime. In the last few years, there has been a move to standardise classification systems of single homicides and establish their cross‐national generalisability. Literature on serial homicide to date has mostly centred on homicides occurring in the US. However, national differences due to factors such as culture, national identity, political, and socio‐economic circumstances may decrease the applicability of these models or certain aspects thereof in other countries and thus must be evaluated. The present study tested the applicability in the South African context of a recently developed US‐based serial homicide crime scene classification framework. Specifically, this study compared the thematic differentiation in planning and violent behaviours that the offenders engage in and how this differentiation compares with that in the US. The sample consisted of 25 homicides that were in total responsible for the murder of 267 victims. Results indicated that overall, the framework is useful and applicable in the South African sample, but important environmental and contextual constraints must be taken into account. Copyright © 2014 John Wiley & Sons, Ltd.
The Effects of Modafinil on Convergent and Divergent Thinking of Creativity: A Randomized Controlled Trial
Authors: Mohamed Ahmed Dahir
Published: September 2014

Modafinil is a drug licensed for the treatment of narcolepsy and sleep apnea. Recently, modafinil has been reported to be used as a pharmacological cognitive enhancer by healthy individuals with no psychiatric disorders. This paper reports on a study that investigated the effects of modafinil on divergent and convergent thinking tasks of creativity. Sixty‐four healthy male (n = 31) and female (n = 33) volunteers participated in a randomized double‐blind placebo‐controlled parallel group design study. For the convergent thinking tasks, modafinil had no significant main effect on the Group Embedded Figures Task and the Remote Associates Task (RAT). However, a median split analysis showed that modafinil participants low in creativity personality trait had significantly higher RAT scores (Mean [M] = 6.85, SD = 3.39; 95% confidence interval [95% CI]: 5.53–8.2) than those high in creativity personality trait (M = 4.27, SD = 3.0; 95% CI: 2.4–6.0). For the divergent thinking tasks, relative to placebo (M = 1.195, SD = 0.28; 95% CI: 1.0–1.3), modafinil (M = 0.77, SD = 0.37; 95% CI: 0.63–0.92) significantly reduced the performance of flexibility scores and marginally reduced the elaboration scores as measured by the Abbreviated Torrance Test for Adults (ATTA). Overall, participants on modafinil (M = 6.3, SD = 2.6; 95% CI: 5.3–7.4) had significantly lower ATTA scores relative to participants on placebo (M = 9.5, SD = 2.3; 95% CI: 8.6–10.4). These results indicate that modafinil might reduce divergent thinking of creativity in healthy individuals. They suggest that, rather than being a more general cognitive enhancer, modafinil might have negative and subtle effects on creativity. However, the results are from a small‐scale trial, which tested a small number of participants. Therefore, the results need to be interpreted with caution. A replication with a large sample of participants is recommended.
Nut traits and nutritional composition of hazelnut (Corylus avellanaL.) as influenced by zinc fertilization
Authors: Özenç Nedim , Bender Özenç Damla
Published: September 2014

BACKGROUND

Zinc is an essential element for plants and its deficiency is a widespread problem throughout the world, causing decreased yields and nutritional quality. In this study the effect of zinc fertilization on some nut traits and the nutritional composition of ‘Tombul’ hazelnut (Corylus avellanaL.) variety cultivated in the Black Sea region of Turkey was investigated and the contribution of this nut to human nutrition determined. Trials were carried out at ‘Tombul’ hazelnut orchards, and zinc fertilizers were applied at 0, 0.2, 0.4, 0.8 and 1.6 kg Zn ha−1in three consecutive years.

RESULTS

Significant differences in some nut traits and mineral composition (protein, total oil, ash, kernel percentage, empty and wrinkled nuts, copper, boron, manganese and molybdenum) were observed with zinc fertilizer applications. In terms of daily nutritional element requirements, 100 g of hazelnut provided about 44.74% phosphorus, 13.39% potassium, 19.32% calcium, 37.49% magnesium, 0.19% sodium, 51.63% iron, 25.73% zinc and 14.05% boron of the recommended daily amounts (RDAs), while copper, manganese and molybdenum contents exceeded theirRDAs.

CONCLUSION

In order to improve some nut traits and the mineral composition of hazelnut, 0.8 and 1.6 kg Zn ha−1fertilizations could be recommended in practice. © 2014 Society of Chemical Industry
Separation of triterpenoid saponins from the root of Bupleurum falcatum by counter current chromatography: The relationship between the partition coefficients and solvent system composition
Authors: Lee Kyoung Jin , Xu Mei‐Ying , Shehzad Omer , Seo Eun Kyoung , Kim Yeong Shik
Published: September 2014

A separation method using counter current chromatography coupled with an evaporative light‐scattering detection system was developed to purify five triterpenoid saponins from the roots of Bupleurum falcatum. The methanol extract was loaded onto a Diaion® HP20 column and fractionated by a methanol and water gradient elution. The saikosaponin‐enriched fraction was obtained by elution with 100% methanol. The two‐phase solvent systems used for separation were composed of chloroform/methanol/isopropanol/water at a volume ratio of 60:60:1:60 and 6:6:1:6. The relationship between the isopropanol ratio of each phase and the partition coefficients of the target compounds was investigated by calculating partition coefficient by high‐performance liquid chromatography and measuring the accurate composition of each phase by 1H NMR spectroscopy. Each fraction obtained was collected and dried, which yielded the following five saikosaponins from 700 mg of injected sample: saikosaponin B1 (8.7 mg), saikosaponin A (86 mg), saikosaponin B3 (17 mg), saikosaponin B2 (41 mg), and saikosaponin C (33 mg). Saikosaponin A showed the most potent cytotoxicity against human cancer cells (gastric cancer, AGS cells; breast cancer, MCF‐7 cells; and hepatoma, HepG2 cells) after 24 h. The IC50 values for the above three cell types were 34.6, 33.3, and 23.4 μmol/L, respectively.
Rapid End‐Group Modification of Polysaccharides for Biomaterial Applications in Regenerative Medicine
Authors: Bondalapati Somasekhar , Ruvinov Emil , Kryukov Olga , Cohen Smadar , Brik Ashraf
Published: September 2014

Polysaccharides have emerged as important functional materials because of their unique properties such as biocompatibility, biodegradability, and availability of reactive sites for chemical modifications to optimize their properties. The overwhelming majority of the methods to modify polysaccharides employ random chemical modifications, which often improve certain properties while compromising others. On the other hand, the employed methods for selective modifications often require excess of coupling partners, long reaction times and are limited in their scope and wide applicability. To circumvent these drawbacks, aniline‐catalyzed oxime formation is developed for selective modification of a variety of polysaccharides through their reducing end. Notably, it is found that for efficient oxime formation, different conditions are required depending on the composition of the specific polysaccharide. It is also shown how our strategy can be applied to improve the physical and functional properties of alginate hydrogels, which are widely used in tissue engineering and regenerative medicine applications. While the randomly and selectively modified alginate exhibits similar viscoelastic properties, the latter forms significantly more stable hydrogel and superior cell adhesive and functional properties. Our results show that the developed conjugation reaction is robust and should open new opportunities for preparing polysaccharide‐based functional materials with unique properties.

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Multidetector Thermal Field‐Flow Fractionation as a Novel Tool for the Microstructure Separation of Polyisoprene and Polybutadiene
Authors: Greyling Guilaume , Pasch Harald
Published: September 2014

For the first time, it is demonstrated that thermal field‐flow fractionation (ThFFF) is an efficient tool for the fractionation of polyisoprene (PI) and polybutadiene (PB) with regard to molecular microstructure. ThFFF analysis of 1,4‐ and 3,4‐PI as well as 1,4‐ and 1,2‐PB samples in tetrahydrofuran (THF), THF/cyclohexane, and cyclohexane reveals that isomers of the same polymer family having similar molar masses exhibit different Soret coefficients depending on microstructure for each solvent. The separation according to microstructure is found to be based on the cooperative influence of the normal and the thermal diffusion coefficient. Of the three solvents, cyclohexane has the greatest influence on the fractionation of the isomers. In order to determine the distribution of isomeric structures in the PI and PB samples, the samples are fractionated by ThFFF in cyclohexane and subsequently analyzed by 1H NMR. The isomeric distributions determined from NMR data correlate well with ThFFF retention data of the samples and thus further highlight the unique fractionating capabilities of ThFFF. The interplay of the normal and thermal diffusion coefficients that are influenced by temperature and the mobile phase opens the way to highly selective fractionations without the drawbacks of column‐based separation methods.

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Identification and characterization of genes differentially expressed in X and Y sperm using suppression subtractive hybridization and cDNA microarray
Authors: Chen Xiaoli , Yue Yang , He Yanan , Zhu Huabin , Hao Haisheng , Zhao Xueming , Qin Tong , Wang Dong
Published: September 2014

Differential expression of genes leads to variations in the phenotypes of X and Y sperm, although some differentially expressed gene products are shared through intercellular bridges. Genes differentially expressed in bovine X and Y sperm were identified by a combination of suppression subtractive hybridization (SSH), cDNA microarray, and sequence‐homology analysis. Microarray data and Significance Analysis of Microarrays software were used to identify 31 differentially expressed genes, only four of which were previously identified. These genes are involved in fundamental life processes of mature sperm, and may be associated with the differences between X and Y sperm since 27 versus 4 were upregulated in X versus Y sperm, respectively. The levels of expression of seven genes—including the known genes UTY, DPH3, CYTB, and ISCU, and the unknown genes X + Y contig 41, X + Y contig 18, and Y + X contig 16—were validated by quantitative real‐time PCR, and some genes were clearly differentially expressed by X and Y sperm, despite the presence of intercellular bridges among spermatids. These results provide a theoretical basis for research on gene expression during sperm development, as well as on sex control at the level of sperm. Mol. Reprod. Dev. 81: 908–917, 2014. © 2014 Wiley Periodicals, Inc.
Simultaneous exposure to MRI‐related static and low‐frequency movement‐induced time‐varying magnetic fields affects neurocognitive performance: A double‐blind randomized crossover study
Authors: van Nierop Lotte E. , Slottje Pauline , van Zandvoort Martine , Kromhout Hans
Published: September 2014

Purpose

This experimental study aims to separate neurocognitive effects resulting from exposure to static magnetic stray fields (SMF) alone and the combination of SMF and low‐frequency movement‐induced time‐varying magnetic fields (TVMF) using a 7 Tesla (T) MRI scanner in stand‐by mode.

Methods

In a double‐blind randomized crossover experiment, 36 healthy volunteers underwent four sessions, two exposed conditions, and two corresponding sham conditions. The exposure conditions were in front of the scanner bore and consisted of 1.0 T SMF with or without 2.4 T/s TVMF, induced by standardized head movements before each of the five neurocognitive tasks. These specific tasks were selected because previous experiments showed negative effects of SMF + TVMF exposure on test performance.

Results

Exposure to SMF in combination with TVMF decreased verbal memory performance significantly and changed visual acuity. Similarly, attention and concentration were negatively affected with borderline significance. Exposure to SMF only did not have significant effects on the performance on any of the tasks.

Conclusion

Neurocognitive effects were only observed when simultaneously exposed to SMF and TVMF from a 7 T MRI scanner. Therefore, exposure to TVMF seems essential in eliciting the neurocognitive effects in our present study and, presumably, previous experiments. Magn Reson Med 74:840–849, 2015. © 2014 Wiley Periodicals, Inc.
In vitro study to simulate the intracardiac magnetohydrodynamic effect
Authors: Buchenberg Waltraud B. , Mader Wolfgang , Hoppe Georg , Lorenz Ramona , Menza Marius , Büchert Martin , Timmer Jens , Jung Bernd
Published: September 2014

Purpose

Blood flow causes induced voltages via the magnetohydrodynamic (MHD) effect distorting electrograms (EGMs) made during magnetic resonance imaging. To investigate the MHD effect in this context MHD voltages occurring inside the human heart were simulated in an in vitro model system inside a 1.5 T MR system.

Methods

The model was developed to produce MHD signals similar to those produced by intracardiac flow and to acquire them using standard clinical equipment. Additionally, a new approach to estimate MHD distortions on intracardiac electrograms is proposed based on the analytical calculation of the MHD signal from MR phase contrast data.

Results

The recorded MHD signals were similar in magnitude to intracardiac signals that would be measured by an electrogram of the left ventricle. The dependency of MHD signals on magnetic field strength and electrode separation was well reflected by an analytical model. MHD signals reconstructed from MR flow data were in excellent agreement with the MHD signal measured by clinical equipment.

Conclusion

The in vitro model allows investigation of MHD effects on intracardiac electrograms. A phase contrast MR scan was successfully applied to characterize and estimate the MHD distortion on intracardiac signals allowing correction of these effects. Magn Reson Med 74:850–857, 2015. © 2014 Wiley Periodicals, Inc.
Maternal Behavior and Infant Physiology During Feeding in Premature and Term Infants Over the First Year of Life
Authors: Weber Ashley M. , Harrison Tondi M.
Published: September 2014

Little is known about the relationship between maternal behavior and the stability of premature infants' physiologic responses during feeding. In a secondary data analysis, we examined relationships between quality of maternal behavior and cardiorespiratory physiology during feeding in 61 premature and 53 term infants at four times over the first year of life. Measures included heart rate (HR), respiratory rate (RR), and oxygen saturation; Child Feeding Skills Checklist; and Parent‐Child Early Relational Assessment. Birthweight, gestational age, and neurodevelopmental risk were covariates. Quality of maternal behavior did not predict infants' physiologic response to feeding. However, birthweight was related to infant feeding physiology among all infants over the first year of life. Stress during fetal life, which may lead to impaired intrauterine growth and low birthweight, may have longitudinal effects on cardiorespiratory functioning of premature infants. Research is needed to further investigate the biological pathways by which maternal–infant interaction supports behavioral and physiologic feeding outcomes of premature infants. © 2014 Wiley Periodicals, Inc.
Morphology and mechanical properties of PP/POE/nano‐CaCO3 composites
Authors: Liang Ji‐Zhao , Zhu Bo , Ma Wen‐Yong
Published: September 2014

The mechanical properties including tensile, flexural, and impact of the nanometer on calcium carbonate (nano‐CaCO3) filled polypropylene (PP)/poly (ethylene‐co‐octene) (POE) composites were measured at room temperature to identify the effects of the POE content on the mechanical properties. It was found that the Young's modulus, tensile strength, and tensile elongation at break decreased nonlinearly while the tensile fracture strength varied slightly with increasing the POE weight fraction; the V‐notched and unnotched Izod impact fracture strength increased nonlinearly with an increase of the POE weight fraction; the flexural modulus and strength decreased roughly linearly with increasing the POE weight fraction. Furthermore, the impact fracture surface of the specimens was observed by means of a scanning electronic microscope to discuss the toughening mechanisms. POLYM. COMPOS., 37:539–546, 2016. © 2014 Society of Plastics Engineers
Properties of Cu nanoparticles–poly(N‐methylpyrrole) composites
Authors: Sanchez‐Jiménez Margarita , Estrany Francesc , Alemán Carlos
Published: September 2014

Spherical copper nanoparticles (Cu‐NPs) have been immobilized on the compact surface of potentiostatically generated poly(N‐methylpyrrole) (PNMPy) films by applying a reduction potential of −0.60 V to a deionized water solution of CuCl2. Although the number density of Cu‐NPs obtained using this procedure is not high (4·106 cm−2), the average diameter is relatively high (∼50 nm). The surface topology and roughness of films with Cu‐NPs–PNMPy are intermediate between those obtained for as prepared PNMPy and reduced PNMPy. Analysis of the electrochemical properties indicates that Cu‐NPs promote the electroactivity of the PNMPy, this effect being more evident for composited made with the thinnest PNMPy films. In opposition, the electrostability and electrical conductivity are not enhanced by deposited Cu‐NPs. Similar findings are obtained for bilayered PNMPy–Cu‐NPs–PNMPy films. POLYM. COMPOS., 37:594–601, 2016. © 2014 Society of Plastics Engineers
Effect of hybridization and chemical treatment on the mechanical properties of coir pith/nylon/epoxy hybrid composites
Authors: Narendar R. , Dasan K. Priya , Jayachandran Jeenet
Published: September 2014

The aim of the work was to develop environmental friendly coir pith–based composites with a good balance of mechanical properties. Multilayered coir pith/nylon fabric/epoxy hybrid composites were fabricated by the hand lay‐up technique followed by compression molding. A set of composites of same composition having chemically treated coir pith was also prepared. Mechanical properties of composites such as tensile strength, impact strength, flexural strength, hardness, and abrasion resistance were evaluated. The hybridization with nylon fabric and the chemical treatment of coir pith enhances the mechanical properties of composites. Chemical resistance and void content of the composites were also determined and reported. A comparative evaluation is done between composites having chemically treated coir pith and untreated coir pith. Coir pith was subjected to different treatments such as sodium hydroxide treatment followed by sulfuric acid, dicumyl peroxide, sodium hypochlorite, acrylic acid, and acetic acid. POLYM. COMPOS., 37:649–657, 2016. © 2014 Society of Plastics Engineers
Studying the mechanical properties of composites made of Kenaf‐Nylon 66 fabric, silica nanoparticles, and epoxy resin
Authors: Alizadeh Masoud , Lohrasby Farshad , Khajavi Ramin , Kordani Naser , Baharvandi Hamid Reza , Rezanejad Moein
Published: September 2014

In this study, the effect of the relationship between yarn material and yarn count tex on the mechanical behavior of plainly woven hybrid fabrics impregnated with silica nanoparticles and epoxy resin has been investigated. First, various types of bicomponent and single‐component fabrics with plain weaves are prepared using kenaf and nylon‐66 yarns with yarn tex count of 334 and 427. To prepare the composite, silica nanoparticles with a particle size of 200 nm are mechanically mixed into glycol polyethylene with a molecular weight of 200 along with ethanol in proportions of 6:1. The weight percent of silica particles in the suspension has been selected as 60%. Using a round edge indenter, the concentrated indentation force test has been performed based on the 6264D standard to determine the strength of each fabric sample. Then, by impregnating the mentioned fabrics with polymer materials (silica nanoparticles and epoxy resin) and performing the concentrated force tests again, it is found that the hybrid fabrics with a yarn tex count of 427 and impregnated with polymer material enjoy the highest shear thickening properties. POLYM. COMPOS., 37:674–683, 2016. © 2014 Society of Plastics Engineers
Enhancement of organoclay on thermal and flame retardant properties of polystyrene/magnesium hydroxide composite
Authors: Liu Jichun , Zhang Yanbin , Yu Zhuoli , Yang Weiyuan , Luo Jie , Pan Bingli , Lu Chang
Published: September 2014

Organoclay (organically modified montmorillonite, OMMT) was introduced to the composite of polystyrene/magnesium hydroxide (PS/MH) by melt compounding. The structure of the obtained PS/MH/OMMT composite was characterized by X‐ray diffraction and transmission electron microscopy. Thermal degradation behavior and flame retardancy of the composite were investigated by various means. It is shown that the PS/MH/OMMT composite has an intercalated nanostructure with the PS chains intercalated between the OMMT layers and the MH particles dispersed evenly in the PS matrix. Compared with the PS/MH composite containing identical amount of flame retardant, the introduction of OMMT has increased the thermal degradation temperature and lowered the mass loss rate at high temperatures. The PS/MH/OMMT nanocomposite can produce a more continuous and compact charred residue layer upon degradation both in air and burnt in flame than the PS/MH composite. Because of formation of this highly thermally stable and insulating charred residue layer, the nanocomposite exhibits much improved thermal endurance, flame retardancy, smoke suppression, and dripping resistance. Moreover, the combination of MH and OMMT makes the composite more difficult to ignite and decreases the release of toxic gas. The advantage of the PS/MH/OMMT nanocomposite is more pronounced in the early stage of combustion. POLYM. COMPOS., 37:746–755, 2016. © 2014 Society of Plastics Engineers
High permittivity nanocomposites fabricated from electrospun polyimide/BaTiO3 hybrid nanofibers
Authors: Xu Wenhui , Ding Yichun , Jiang Shaohua , Ye Wan , Liao Xiaojian , Hou Haoqing
Published: September 2014

High dielectric permittivity, good mechanical properties, and excellent thermal stability are highly desired for the dielectric materials used in the embedded capacitors and energy‐storage devices. This study reports polyimide (PI)/barium titanate (BaTiO3) nanocomposites fabricated from electrospun PI/BaTiO3 hybrid nanofibers. The PI/BaTiO3 nanocomposites were investigated using Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscope, thermal gravimetric analysis, an electromechanical testing machine, a LCR meter and an electric breakdown strength tester. The results showed that BaTiO3 fillers were uniformly dispersed up to 50 vol% in PI matrix. The dielectric permittivity of the composite (50 vol% BaTiO3) was 29.66 with a dielectric loss of 0.009 at 1 kHz and room temperature. The dielectric permittivity showed a very small dependence on temperature (up to 150°C) and frequency (100 Hz–100 kHz). The nanocomposites also showed high thermal stability and good mechanical properties. The PI/BaTiO3 nanocomposites will be a promising candidate for uses in embedded capacitors, especially in high temperature circumstance. POLYM. COMPOS., 37:794–801, 2016. © 2014 Society of Plastics Engineers
Strategies for Improving Codes of Ethics Implementation in Construction Organizations
Authors: Olugbenga Oladinrin T. , Ho Christabel Man-Fong
Published: September 2014

It is necessary to reconsider the assumptions upon which the process of implementing compliance with ethical programs rests, in both theoretical and practical terms. These assumptions should hinge on organizational enablers that allow embeddedness of codes of ethics in the web of an organization's processes. This article sets out to describe an approach that will facilitate implementation of codes of ethics in construction organizations and a comprehensive literature survey approach is adopted to achieve this. The paper equally employs the application of the European Foundation for Quality Management (EFQM) model as a tool to stimulate ethical behavior in an organization, with the focus on the enabler criterion of the model. The authors discuss organizational enablers in relation to the implementation of ethical codes. The study demonstrates how ethics can be managed in an organization by proposing a framework to enhance codes of ethics embeddedness in the web of an organization. The paper indicates current research gaps and future opportunities for both academics and practitioners.
Influence of Trade-Level Coordination Problems on Project Productivity
Authors: Hwang Bon-Gang , Zhao Xianbo , van Do Thi Hong
Published: September 2014

This study aims to investigate the influence of coordination problems in glass and metal curtain wall (GMCW) installation on project productivity in Singapore. Trade-level coordination problems in GMCW installation were identified through literature review and included in a survey questionnaire. The survey results indicated that, on average, 66.5 days of rework and 52.5 days of waiting resulted from coordination problems, and that “last-minute changes in design by the client” led to the longest rework and waiting time. Additionally, the rework and waiting time caused by trade-level coordination problems were correlated with the total rework and waiting time.
Perspectives on the Formal Authority between Project Managers and Change Managers
Authors: Pollack Julien , Algeo Chivonne
Published: September 2014

Project management and change management both contribute to the management and delivery of changes to organizations; however, they are based on distinct bodies of knowledge, and practitioners of these disciplines have disparate views on how change should be managed. There is a lack of consensus about how these disciplines should work together to deliver organizational change projects, which may result in conflict. This research delves into practitioners' perspectives on formal authority, the reporting relationship between these disciplines, and also reveals the fundamental differences in how practitioners of these disciplines view the practice of organizational change.
Ambidexterity and Knowledge Strategy in Major Projects: A Framework and Illustrative Case Study
Authors: Turner Neil , Maylor Harvey , Lee-Kelley Liz , Brady Tim , Kutsch Elmar , Carver Stephen
Published: September 2014

We develop a framework to analyze the multilevel knowledge requirements of complex, major projects in terms of ambidexterity–-the ability to exploit (refine existing knowledge) and explore (develop new knowledge). This is an important theme within the wider literature, yet practical operationalization methods for managers and researchers are not evident. We demonstrate the ambidexterity view through an illustrative case study of telecommunications delivery for the London 2012 Olympic Games and show how these concepts can be used to create an effective knowledge strategy. We offer a structure for the analysis of knowledge utilization in projects.
Empirical valence bond simulations of the hydride transfer step in the monoamine oxidase B catalyzed metabolism of dopamine
Authors: Repič Matej , Vianello Robert , Purg Miha , Duarte Fernanda , Bauer Paul , Kamerlin Shina C. L. , Mavri Janez
Published: September 2014

Monoamine oxidases (MAOs) A and B are flavoenzymes responsible for the metabolism of biogenic amines such as dopamine, serotonin and noradrenaline. In this work, we present a comprehensive study of the rate‐limiting step of dopamine degradation by MAO B, which consists in the hydride transfer from the methylene group of the substrate to the flavin moiety of the FAD prosthetic group. This article builds on our previous quantum chemical study of the same reaction using a cluster model (Vianello et al., Eur J Org Chem 2012; 7057), but now considering the full dimensionality of the hydrated enzyme with extensive configurational sampling. We show that MAO B is specifically tuned to catalyze the hydride transfer step from the substrate to the flavin moiety of the FAD prosthetic group and that it lowers the activation barrier by 12.3 kcal mol−1 compared to the same reaction in aqueous solution, a rate enhancement of more than nine orders of magnitude. Taking into account the deprotonation of the substrate prior to the hydride transfer reaction, the activation barrier in the enzyme is calculated to be 16.1 kcal mol−1, in excellent agreement with the experimental value of 16.5 kcal mol−1. Additionally, we demonstrate that the protonation state of the active site residue Lys296 does not have an influence on the hydride transfer reaction. Proteins 2014; 82:3347–3355. © 2014 Wiley Periodicals, Inc.
Polyanion binding accelerates the formation of stable and low‐toxic aggregates of ALS‐linked SOD1 mutant A4V
Authors: Zhao Dan , Zhang Shibing , Meng Yan , Xiongwei Dong , Zhang Dan , Liang Yi , Wang Li , Liu Changlin
Published: September 2014

The toxic property thus far shared by both ALS‐linked SOD1 variants and wild‐type SOD1 is an increased propensity to aggregation. However, whether SOD1 oligomers or aggregates are toxic to cells remains to be well defined. Moreover, how the toxic SOD1 species are removed from intra‐ and extracellular environments also needs to be further explored. The DNA binding has been shown to be capable of accelerating the aggregatio\n of wild‐type and oxidized SOD1 forms under acidic and neutral conditions. In this study, we explore the binding of DNA and heparin, two types of essential life polyanions, to A4V, an ALS‐linked SOD1 mutant, under acidic conditions, and its consequences. The polyanion binding alters the A4V conformation, neutralizes its local positive charges, and increases its local concentrations along the polyanion chain, which are sufficient to lead to acceleration of the pH‐dependent A4V aggregation. The accelerated aggregation, which is ascribed to the polyanion binding‐mediated removal or shortening of the lag phase in aggregation, contributes to the formation of amorphous A4V nanoparticles. The prolonged incubation with polyanions not only results in the complete conversion of likely soluble toxic A4V oligomers into non‐ and low‐toxic SDS‐resistant aggregates, but also increases their stability. Although this is only an initial step toward reducing the toxicity of SOD1 mutants, the accelerating role of polyanions in protein aggregation might become one of the rapid pathways that remove toxic forms of SOD1 mutants from intra‐ and extracellular environments. Proteins 2014; 82:3356–3372. © 2014 Wiley Periodicals, Inc.
Hints for the metallic phase in Rb4C60 under pressure
Authors: Francis E. A. , Kuntscher C. A.
Published: September 2014

The alkali fulleride Rb4C60 was investigated by infrared spectroscopy under high pressure, to study the vibrational and electronic excitations. The material exhibits a bad metal behavior in the measured pressure range (0.8–8 GPa). With increasing pressure the Drude term in the far‐infrared region increases, which signals an increasing metallic character. By following the optical excitations under pressure, we could attribute the underlying mechanism of the pressure‐induced insulator‐to‐metal transition in Rb4C60 to the closing of the charge gap, and the nanoscale phase separation scenario discussed in the literature seems to be unlikely.
Theoretical electron energy loss spectroscopy of isolated graphene
Authors: Mowbray Duncan J.
Published: September 2014

A thorough understanding of the electronic structure is a necessary first step for the design of nanoelectronics, chemical/bio‐sensors, electrocatalysts and nanoplasmonics using graphene. As such, theoretical spectroscopic techniques to describe collective excitations of graphene are of fundamental importance. Starting from density functional theory (DFT), linear response time dependent DFT in frequency‐reciprocal space within the random phase approximation (TDDFT‐RPA) is used to describe the loss function for isolated graphene. To ensure any spurious interactions between layers are removed, both radial cutoff of the Coulomb kernel, and extra vacuum directly at the TDDFT‐RPA level are employed. A combination of both methods is found to provide a correct description of the electron energy loss spectra of isolated graphene, at a significant reduction in computational cost compared to standard methods.
p‐Times differentiable unbounded functions for robust control of uncertain switched nonlinear systems with tracking constraints
Authors: Niu Ben , Zhao Xudong , Zhang Lixian , Li Hongyi
Published: September 2014

This paper investigates the problem of robust controller design for output‐constrained and state‐constrained uncertain switched nonlinear systems. By using the idea of p‐times differentiable unbounded functions and the backstepping technique, a constructive method is proposed to design effective controllers such that the output of a class of uncertain switched nonlinear systems in lower triangular form can asymptotically track a constant reference signal without violation of the output tracking error constraint. Furthermore, the explored method is applied to the state‐constrained robust stabilization problem for a class of general uncertain switched nonlinear systems. Finally, a simulation example is provided to demonstrate the effectiveness of the developed results. Copyright © 2014 John Wiley & Sons, Ltd.
Dense Omnidirectional RGB‐D Mapping of Large‐scale Outdoor Environments for Real‐time Localization and Autonomous Navigation
Authors: Meilland Maxime , Comport Andrew I. , Rives Patrick
Published: September 2014

This paper presents a novel method and innovative apparatus for building three‐dimensional (3D) dense visual maps of large‐scale unstructured environments for autonomous navigation and real‐time localization. The main contribution of the paper is focused on proposing an efficient and accurate 3D world representation that allows us to extend the boundaries of state‐of‐the‐art dense visual mapping to large scales. This is achieved via an omnidirectional key‐frame representation of the environment, which is able to synthesize photorealistic views of captured environments at arbitrary locations. Locally, the representation is image‐based (egocentric) and is composed of accurate augmented spherical panoramas combining photometric information (RGB), depth information (D), and saliency for all viewing directions at a particular point in space (i.e., a point in the light field). The spheres are related by a graph of six degree of freedom (DOF) poses (3 DOF translation and 3 DOF rotation) that are estimated through multiview spherical registration. It is shown that this world representation can be used to perform robust real‐time localization (in 6 DOF) of any configuration of visual sensors within their environment, whether they be monocular, stereo, or multiview. Contrary to feature‐based approaches, an efficient direct image registration technique is formulated. This approach directly exploits the advantages of the spherical representation by minimizing a photometric error between a current image and a reference sphere. Two novel multicamera acquisition systems have been developed and calibrated to acquire this information, and this paper reports for the first time the second system. Given the robustness and efficiency of this representation, field experiments demonstrating autonomous navigation and large‐scale mapping will be reported in detail for challenging unstructured environments, containing vegetation, pedestrians, varying illumination conditions, trams, and dense traffic.
Automatic Extrinsic Calibration of Vision and Lidar by Maximizing Mutual Information
Authors: Pandey Gaurav , McBride James R. , Savarese Silvio , Eustice Ryan M.
Published: September 2014

This paper reports on an algorithm for automatic, targetless, extrinsic calibration of a lidar and optical camera system based upon the maximization of mutual information between the sensor‐measured surface intensities. The proposed method is completely data‐driven and does not require any fiducial calibration targets—making in situ calibration easy. We calculate the Cramér‐Rao lower bound (CRLB) of the estimated calibration parameter variance, and we show experimentally that the sample variance of the estimated parameters empirically approaches the CRLB when the amount of data used for calibration is sufficiently large. Furthermore, we compare the calibration results to independent ground‐truth (where available) and observe that the mean error empirically approaches zero as the amount of data used for calibration is increased, thereby suggesting that the proposed estimator is a minimum variance unbiased estimate of the calibration parameters. Experimental results are presented for three different lidar‐camera systems: (i) a three‐dimensional (3D) lidar and omnidirectional camera, (ii) a 3D time‐of‐flight sensor and monocular camera, and (iii) a 2D lidar and monocular camera.
Water ethics on a human‐dominated planet: rationality, context and values in global governance
Authors: Schmidt Jeremy J. , Peppard Christiana Z.
Published: September 2014

A discourse on water ethics has emerged as a field linking practical water demands, social practices, and hydrological constraints to philosophic norms. The field arose parallel to growing, global understandings of the interconnected nature of water management and governance challenges. As such, it has been inflected with issues and contests across a range of policy concerns—from holistic and integrated water management to economics, justice, and human rights. The emerging water ethics discourse challenges both traditional environmental ethics and conventional approaches to resource management on issues of gender, power relations, and ecological concerns. It suggests an alternate, place‐specific approach for linking shared water concerns to normative contests.WIREs Water2014, 1:533–547. doi: 10.1002/wat2.1043

This article is categorized under:

Human Water > Rights to Water

Human Water > Value of Water

Human Water > Water Governance