bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergency Nursing, Ebola, and Public Policy: The Contributions of Nursing to the Public Policy Conversation
Authors: Wolf Lisa , Ulrich Connie M. , Grady Christine
Published: September 2016

Excellent patient care within the emergency department requires interdisciplinary training, teamwork, and communication to manage the chaos of the environment. Specifically, invasive procedures required to manage airway, breathing, and circulation via intubation, chest compressions, and establishing intravenous access can provide a direct benefit to save lives but also have the potential to harm both patients and health care clinicians alike; emergency health care clinicians can be exposed to significant amounts of blood and body fluids as well as other threats of physical and psychological harm. The ethical components of care in this environment are often under‐recognized due to the need for rapid patient assessment and immediate action. Moreover, challenges to practice that can include lack of qualified personnel, equipment, and other resources to provide safe care to a large volume of patients can lead to moral distress in ED staff. Because the ED is a high‐uncertainty, high‐acuity environment, continuing interprofessional communication, collaboration, and planning is critical. Opportunities for multidisciplinary policy dialogue and the development of professional guidelines can make the ED a safer environment for both patients and providers.
Primary payer status, individual patient characteristics, and hospital‐level factors affecting length of stay and total cost of hospitalization in total laryngectomy
Authors: Mehta Vikas , Flores José M. , Thompson Richard Will , Nathan Cherie‐Ann
Published: September 2016

Background

Medicaid and uninsured patients anecdotally incur higher cost and length of stay because of nonmedical, discharge‐related factors. The purpose of this study was to investigate the association between primary payer and length of stay and cost, controlling for comorbidities and complications, in patients undergoing total laryngectomy.

Methods

The sample included 4128 patients who underwent total laryngectomy in the 2005 to 2010 National Inpatient Sample (NIS). Patients were categorized into 4 subgroups based on payer status: Medicare, Medicaid, uninsured, and private insurance. Using multilevel modeling, we examined differences in length of stay and hospitalization costs.

Results

The odds of being in the top quartile of length of stay increased for Medicaid patients by 41% (odds ratio [OR] = 1.41; 95% confidence interval [CI] = 1.03–1.92) compared with privately insured patients.

Conclusion

After controlling for medical factors, Medicaid patients had increased lengths of stay. Overall costs were highest for those with public insurance, but no difference was seen for the adjusted cost. © 2016 Wiley Periodicals, Inc. Head Neck 39: 311–319, 2017
Slow stabilization of concurrently acquired hippocampal context representations
Authors: Law L. Matthew , Bulkin David A. , Smith David M.
Published: September 2016

Hippocampal neurons exhibit spatially localized firing patterns that, at the population level, represent a particular environment or context. Many studies have examined how hippocampal neurons switch from an existing representation to a new one when the environment is changed, a process referred to as remapping. New representations were commonly thought to emerge rapidly, within a few minutes and then remain remarkably stable thereafter. However, a number of recent studies suggest that hippocampal representations may be more fluid than previously thought and most of the previous studies only required that subjects switch from a familiar environment to a novel one. In the present study, we examined the concurrent development of two distinct hippocampal representations by exposing rats to two distinct environmental contexts in an ABAB pattern and we recorded neuronal activity for eight daily training sessions. Hippocampal neurons exhibited normal place fields with typical firing properties during the initial exposure to each context on the first day. However, when the rats were returned to the original context after having spent 15 min in the second context, many of the neurons fired in new locations (i.e., they remapped) as if the rat had encountered a new environment. By the third day, the representations had stabilized and were highly consistent across visits to the same context. These results suggest that when subjects concurrently encode multiple contexts, hippocampal representations may require repeated experiences to fully stabilize. © 2016 Wiley Periodicals, Inc.
Energy restriction at young age, genetic variants in the insulin‐like growth factor pathway and colorectal cancer risk in the Netherlands Cohort Study
Authors: Simons Colinda C.J.M. , Schouten Leo J. , Godschalk Roger W. , van Engeland Manon , van den Brandt Piet A. , van Schooten Frederik J. , Weijenberg Matty P.
Published: September 2016

The energy restriction (ER)‐colorectal cancer (CRC) association is inconsistent in literature. To strengthen the biological plausibility of the ER‐CRC association, we investigated whether genetic variation in the insulin‐like growth factor (IGF) pathway, a putative underlying mechanism, modulated this association in the Netherlands Cohort Study. Participants completed a questionnaire (n = 120,852) and provided toenail clippings for DNA (∼75%) at baseline. Individuals living in a Western city during the Hunger Winter (1944–45) or Western rural versus non‐Western area were exposed to (severe) ER at young age. Genotyping was performed for 3,768 subcohort members and 2,580 CRC cases (case‐cohort with 16.3 years follow‐up). Cox hazard ratios for CRC were estimated across combined categories of ER and a genetic sum score of unfavorable alleles based on 18 single nucleotide polymorphisms in IGF‐related genes and ER and an IGF1 19‐CA repeat polymorphism. The reference included ER exposed individuals, so that increased hazard ratios were expected in higher combined categories for calculating relative excess risks due to interaction (additive interactions). Wald tests for multiplicative interactions were also performed. Multiplicative and additive interactions were nonsignificant. Combined ER‐genetic sum score categories showed increasing CRC risks in men, but confidence intervals were wide. Women carrying two variant IGF1 19‐CA repeat alleles versus those carrying two wild type IGF1 19‐CA repeat alleles were at an ∼50% decreased CRC risk, irrespective of ER exposure. In conclusion, data indicate that the IGF pathway might be involved in the ER‐CRC association in men, but not women, although interactions were nonsignificant, hampering definite conclusions.
Cell response to sterilized electrospun poly(ɛ‐caprolactone) scaffolds to aid tendon regeneration in vivo
Authors: Bhaskar Prajwal , Bosworth Lucy A. , Wong Richard , O'brien Marie A. , Kriel Haydn , Smit Eugene , McGrouther Duncan A. , Wong Jason K. , Cartmell Sarah H.
Published: September 2016

The functional replacement of tendon represents an unmet clinical need in situations of tendon rupture, tendon grafting, and complex tendon reconstruction, as usually there is a finite source of healthy tendon to use as donors. The microfibrous architecture of tendon is critical to the function of tendon. This study investigates the use of electrospun poly(ɛ‐caprolactone) scaffolds as potential biomaterial substitutes for tendon grafts. We assessed the performance of two electrospinning manufacturers (small‐ and large‐scale) and the effect of two sterilization techniques—gamma irradiation and ethanol submersion—on cell response to these electrospun scaffolds after their implantation into a murine tendon model. Cell infiltration and proliferation analyses were undertaken to determine the effect on cell response within the implant over a 6‐week period. Immunohistochemical analysis was performed to characterize inflammatory response and healing characteristics (proliferation, collagen deposition, myofibroblast activity, and apoptosis). Neither the sterilization techniques nor the manufacturer was observed to significantly affect the cell response to the scaffold. At each time point, cell response was similar to the autograft control. This suggests that ethanol submersion can be used for research purposes and that the scaffold can be easily reproduced by a large‐scale manufacturer. These results further imply that this electrospun scaffold may provide an alternative to autograft, thus eliminating the need for sourcing healthy tendon tissue from a secondary site. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 389–397, 2017.
Osteocyte-Secreted Wnt Signaling Inhibitor Sclerostin Contributes to Beige Adipogenesis in Peripheral Fat Depots
Authors: Fulzele Keertik , Lai Forest , Dedic Christopher , Saini Vaibhav , Uda Yuhei , Shi Chao , Tuck Padrig , Aronson Jenna L , Liu Xiaolong , Spatz Jordan M , Wein Marc N , Divieti Pajevic Paola
Published: September 2016

Cells of the osteoblast lineage are increasingly identified as participants in whole-body metabolism by primarily targeting pancreatic insulin secretion or consuming energy. Osteocytes, the most abundant bone cells, secrete a Wnt-signaling inhibitor called sclerostin. Here we examined three mouse models expressing high sclerostin levels, achieved through constitutive or inducible loss of the stimulatory subunit of G-proteins (Gsα in mature osteoblasts and/or osteocytes). These mice showed progressive loss of white adipose tissue (WAT) with tendency toward increased energy expenditure but no changes in glucose or insulin metabolism. Interestingly beige adipocytes were increased extensively in both gonadal and inguinal WAT and had reduced canonical β-catenin signaling. To determine if sclerostin directly contributes to the increased beige adipogenesis, we engineered an osteocytic cell line lacking Gsα which has high sclerostin secretion. Conditioned media from these cells significantly increased expression of UCP1 in primary adipocytes, and this effect was partially reduced after depletion of sclerostin from the conditioned media. Similarly, treatment of Gsα-deficient animals with sclerostin-neutralizing antibody partially reduced the increased UCP1 expression in WAT. Moreover, direct treatment of sclerostin to wild-type mice significantly increased UCP1 expression in WAT. These results show that osteocytes and/or osteoblasts secrete factors regulating beige adipogenesis, at least in part, through the Wnt-signaling inhibitor sclerostin. Further studies are needed to assess metabolic effects of sclerostin on adipocytes and other metabolic tissues. © 2016 American Society for Bone and Mineral Research.
Interfering of the Reelin/ApoER2/PSD95 Signaling Axis Reactivates Dendritogenesis of Mature Hippocampal Neurons
Authors: Ampuero Estibaliz , Jury Nur , Härtel Steffen , Marzolo María‐Paz , van Zundert Brigitte
Published: September 2016

Reelin, an extracellular glycoprotein secreted in embryonic and adult brain, participates in neuronal migration and neuronal plasticity. Extensive evidence shows that reelin via activation of the ApoER2 and VLDLR receptors promotes dendrite and spine formation during early development. Further evidence suggests that reelin signaling is needed to maintain a stable architecture in mature neurons, but, direct evidence is lacking. During activity‐dependent maturation of the neuronal circuitry, the synaptic protein PSD95 is inserted into the postsynaptic membrane to induce structural refinement and stability of spines and dendrites. Given that ApoER2 interacts with PSD95, we tested if reelin signaling interference in adult neurons reactivates the dendritic architecture. Unlike findings in developing cultures, the presently obtained in vitro and in vivo data show, for the first time, that reelin signaling interference robustly increase dendritogenesis and reduce spine density in mature hippocampal neurons. In particular, the expression of a mutant ApoER2 form (ApoER2‐tailless), which is unable to interact with PSD95 and hence cannot transduce reelin signaling, resulted in robust dendritogenesis in mature hippocampal neurons in vitro. These results indicate that reelin/ApoER2/PSD95 signaling is important for neuronal structure maintenance in mature neurons. Mechanistically, obtained immunofluorescent data indicate that reelin signaling impairment reduced synaptic PSD95 levels, consequently leading to synaptic re‐insertion of NR2B‐NMDARs. Our findings underscore the importance of reelin in maintaining adult network stability and reveal a new mode for reactivating dendritogenesis in neurological disorders where dendritic arbor complexity is limited, such as in depression, Alzheimer's disease, and stroke. J. Cell. Physiol. 232: 1187–1199, 2017. © 2016 Wiley Periodicals, Inc.
Allometry Is a Reasonable Choice in Pediatric Drug Development
Authors: Liu Tao , Ghafoori Parima , Gobburu Jogarao V. S.
Published: September 2016

Pharmacokinetics (PK) plays a key role in bridging drug efficacy and safety from adults to pediatric patients. The principal purpose of projecting dosing in pediatrics is to guide trial design, not to waive the study per se. This research was designed to evaluate whether the allometric scaling (AS) approach is a satisfactory method to design PK studies in pediatric patients aged 2 years and older. We systematically evaluated drugs that had pediatric label information updated from 1998 to 2015. Only intravenous (IV) or oral administration drugs with available PK information in both children and adults from FDA‐approved labels were included. The allometric scaling approach was used to extrapolate adult clearance to pediatric clearance. The relative difference between the observed and the allometric scaling approach–predicted clearance was summarized and used to evaluate the predictive power of the allometric scaling approach. A total of 36 drugs eliminated by a metabolic pathway and 10 drugs by the renal pathway after intravenous (IV) or oral administration were included. Regardless of the administration route, elimination pathway, and age group, the allometric scaling approach can predict clearance in pediatric patients within a 2‐fold difference; 18 of the included drugs were predicted within a 25% difference, and 31 drugs within a 50% difference. The allometric scaling approach can adequately design PK studies in pediatric subjects 2 years and older.
Greater Growth of Proximal Metatarsals in Bird Embryos and the Evolution of Hallux Position in the Grasping Foot
Authors: Botelho João Francisco , Smith‐Paredes Daniel , Soto‐Acuña Sergio , Núñez‐León Daniel , Palma Verónica , Vargas Alexander O.
Published: September 2016

In early theropod dinosaurs—the ancestors of birds—the hallux (digit 1) had an elevated position within the foot and had lost the proximal portion of its metatarsal. It no longer articulated with the ankle, but was attached at about mid‐length of metatarsal 2 (mt2). In adult birds, the hallux is articulated closer to the distal end of mt2 at ground level with the other digits. However, on chick embryonic day 7, its position is as in early theropods at half‐length of mt2. The adult distal location is acquired during embryonic days 8–10. To assess how the adult phenotype is acquired, we produced fate maps of the metatarsals of day 6 chicken embryos injecting the lipophilic tracer DiI. The fates of these marks indicate a larger expansion of the metatarsals at their proximal end, which creates the illusory effect that d1 moves distally. This larger proximal expansion occurs concomitantly with growth and early differentiation of cartilage. Histological analysis of metatarsals shows that the domains of flattened and prehypertrophic chondrocytes are larger toward the proximal end. The results suggest that the distal position of the hallux in the avian foot evolved as a consequence of an embryological period of expansion of the metatarsus toward the proximal end. It also brings attention to the developmental mechanisms leading to differential growth between epiphyses and their evolutionary consequences.
Indole‐Fused Epoxy‐1,5‐Diazocines as Cancer‐Selective Cytotoxic Agents
Authors: Faraj Fadhil Lafta , Khaledi Hamid , Karimian Hamed , Ali Hapipah Mohd
Published: September 2016

Dimerization of 2‐(diformylmethylene)‐3,3‐dimethylindole by the action of tosyl chloride (TsCl) led to the creation of an epoxy‐[1,5]‐diazocine bicycle. The structure of the molecule resembles that of the naturally occurring C‐curarine‐I. The molecule shows significant cytotoxicity against cancer lines MCF‐7 and MDA‐MB‐231, but not toward the normal cell line CCD‐841. A series of substituted 2‐(diformylmethylene)‐3,3‐dimethylindoles was accordingly dimerized, and the products were studied for their cytotoxic activities.
Mathematics as a conduit for translational research in post‐traumatic osteoarthritis
Authors: Ayati Bruce P. , Kapitanov Georgi I. , Coleman Mitchell C. , Anderson Donald D. , Martin James A.
Published: September 2016

Biomathematical models offer a powerful method of clarifying complex temporal interactions and the relationships among multiple variables in a system. We present a coupled in silico biomathematical model of articular cartilage degeneration in response to impact and/or aberrant loading such as would be associated with injury to an articular joint. The model incorporates fundamental biological and mechanical information obtained from explant and small animal studies to predict post‐traumatic osteoarthritis (PTOA) progression, with an eye toward eventual application in human patients. In this sense, we refer to the mathematics as a “conduit of translation.” The new in silico framework presented in this paper involves a biomathematical model for the cellular and biochemical response to strains computed using finite element analysis. The model predicts qualitative responses presently, utilizing system parameter values largely taken from the literature. To contribute to accurate predictions, models need to be accurately parameterized with values that are based on solid science. We discuss a parameter identification protocol that will enable us to make increasingly accurate predictions of PTOA progression using additional data from smaller scale explant and small animal assays as they become available. By distilling the data from the explant and animal assays into parameters for biomathematical models, mathematics can translate experimental data to clinically relevant knowledge. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:566–572, 2017.
Behavioral development and habitat structure affect postfledging movements of songbirds
Authors: Jenkins Julianna M. A. , Thompson Frank R. , Faaborg John
Published: September 2016

Postfledging survival of neotropical migrant songbirds has been linked to seasonal and annual changes in the environment and to individual condition. Understanding what influences variation in postfledging movements may provide insight into the differential value of habitat across life‐history stages. We conducted a radio‐telemetry study of postfledging ovenbirds (Seiurus aurocapilla; n = 45) and Acadian flycatchers (Empidonax virescens; n = 62) in mature‐forest fragments from 2012 to 2015 in Missouri, USA. We documented variability in behavior and space use and used generalized linear mixed models to evaluate the relationship of postfledging movement rates to individuals’ condition, temporal variables, and local habitat variables. We found effects of age and season on movement distances for both study species. Additionally, daily movements of fledgling ovenbirds were negatively related to understory foliage density, a characteristic previously linked to increased survival. Habitat features are useful in predicting the postfledging movements of ovenbirds. By including behavioral development (age) and season in movement models, we were able to isolate and detect habitat effects on movement of ovenbirds and Acadian flycatchers. We suggest researchers use models of daily movement to further strengthen resource quality hypotheses generated by habitat selection and survival studies. © 2016 The Wildlife Society.
Habitat modification as a means of restoring crested auklet colonies
Authors: Major Heather L. , Buxton Rachel T. , Schacter Carley R. , Conners Melinda G. , Jones Ian L.
Published: September 2016

Seabirds that forage in dense groups can be especially vulnerable to anthropogenic threats at sea. To mitigate these threats to populations, nesting habitat restoration may be a viable option by reducing negative density dependence. Accordingly, we undertook a before‐after control‐impact (BACI) experiment to test whether habitat modification could be an effective means of restoring nesting habitat of crested auklets (Aethia cristatella) breeding on Gareloi Island, Alaska, USA. Despite supporting large numbers of crevice‐nesting auklets, many lava flows at Gareloi Island are in a stage of late vegetative succession that may prevent birds from accessing subterranean nesting habitat. We hypothesized that crested auklet density is highest in unvegetated blocky and porous lava, and predicted that removing vegetation from the surface would allow new recruits to secure previously unavailable nesting sites. In 2009 and 2010, we delineated 34 200‐m2 plots throughout the southeast colony at Gareloi, and color marked a subset of crested auklets landing in each plot to measure movement and abundance. We removed vegetative overgrowth and peat from half of each plot at the end of the 2009 (4 plots) and 2010 (30 plots) breeding seasons. Before and after vegetation removal, we counted the number of active nesting sites and calculated the ratio of banded to un‐banded breeders on the surface of each plot half. Overall, active nesting sites, number of individuals on the surface, and number of breeders landing did not increase after vegetation removal. However, among banded individuals that moved among plot halves, birds were 1.7 times more likely to move to a de‐vegetated plot half. Based on our experimental results, we found no evidence that vegetation removal increased crested auklet numbers at Gareloi Island, and thus in the short term this may not be a viable option for increasing crested auklet abundance. © 2016 The Wildlife Society.
Processing and Characterization of Composites Curing by Microwave Irradiation
Authors: Kersting Daniel F. , Wiebeck Helio , Esper Fábio J.
Published: September 2016

The present study aimed to assess the curing of composites based on fiberglass and epoxy resin subjected to various microwave irradiation power level and time. The conditions studied were monitored in order to provide thermal images of different times during the irradiation, allowing the visualization of the temperature distribution over time on the test specimens . The heating profile tests resulted in samples that were later analyzed. Pores and voids content, density and thickness were also evaluated according to ASTM. The existing composite were then analyzed via optical microscopy.The samples obtained by thermal curing are less than the amount of pores and voids. Moreover, the cure via microwave required only twenty minutes to accomplish what has been produced in more than thirty hours of thermal curing.
Influence of Binary Curing System on the Nitrile Rubber Mechanical Properties
Authors: Linhares Felipe N. , Kersch Michaela , Sousa Ana Maria F. , Leite Marcia Christina A.M. , Altstädt Volker , Furtado Cristina R.G.
Published: September 2016

The effect of different sulphur‐based curing systems on the nitrile rubber mechanical properties was assessed. High acrylonitrile content nitrile rubber compositions were prepared with different amounts of N‐cyclohexyl‐2‐benzothiazole‐sulfenamide (CBS), tetramethylthiuram disulfide (TMTD) and sulphur. The following tests were conducted: crosslink density, hardness, and stress‐strain tests. Scanning electron microscopy, infrared and NMR spectroscopies, and statistical analyses were carried out to bring new interesting aspects to this topic. Crosslink density was statistically influenced by the amount of TMTD and sulphur, whereas no significance was observed for CBS content. Tensile strength was above the optimum point regarding the crosslink density. Time‐dependent exudation of TMTD was observed when added in higher concentration.
Mechanical and Thermal Behavior of PLA/PEgAA Blends
Authors: de Araújo Jeane P. , Silva Reinaldo C. , Lima Jéssica C. C. , Agrawal Pankaj , de Mélo Tomás J. A.
Published: September 2016

The aim of this work was to evaluate the effect different polyethylene grafted with acrylic acid (PEgAA) copolymer content on the mechanical and thermal properties and morphology of poly(lactic acid) (PLA) biopolymer. The PLA/PEgAA blends containing 5, 10, 15 and 20% (wt) of PEgAA copolymer were prepared by extrusion followed by injection molding and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA), mechanical properties and Scanning Electron Microscopy (SEM). FTIR analysis indicated that a polyesterification reaction between the hydroxyl groups of PLA and the carboxyl groups of PEgAA may have occurred. DSC and DMTA analyzes indicated that the addition of PEgAA to PLA lead to the decrease in cold crystallization (Tcc) temperature of PLA. The impact strength of PLA was increased with the increase in the PEgAA content up to 15%. The PEgAA domains size increased with the increase in the PEgAA content, indicating a weak interaction between the PLA and PEgAA phases.
Nanocomposites of Polyethylene Blends Using Organomica
Authors: Oliveira Patrícia L. , Araújo Rafael S. , Oliveira Vital R. , Morais Jacson S. , de Fátima V. Marques Maria
Published: September 2016

This study aims to incorporate LLDPE into HDPE in order to improve its processability, as well as to employ a nanoclay for maintaining the HDPE stiffness. Thermal, dynamic‐mechanical and rheological properties of polyethylene composites were investigated. Muscovite mica was treated with lithium nitrate for seven cycles, followed by exchange with quaternary ammonium salt to produce organomica. Initially, organomica was added to HDPE at 2% wt. using a tween‐screw mini‐extruder. The blend HDPE/LLDPE (1:1 by weight) was also evaluated at the same mica content, with and without the introduction of maleated polyethylene (PEMA) as compatibilizer in order to increase adhesion of polymers with the mineral clay. The samples were evaluated by thermogravimetry (TGA), while melting and crystallization temperatures, and the degree of crystallinity were measured by differential scanning calorimetry (DSC). Rheological properties were evaluated during blending using viscosity and torque curves as a function of processing time. The results showed that stability to thermal degradation of the polyethylene blend with mica increased with the addition of 2% wt. PEMA, where the temperature of maximum degradation rate overcame that of HDPE. The melting endotherm remained narrow in the mixture HDPE/LLDPE/mica, showing good miscibility of the polymer blend; and there was a slight decrease in the melting temperature. The reduction in viscosity during blending revealed improved processing conditions.
Mechanical and Morphological Properties of PLA/BioPE Blend Compatibilized with E‐GMA and EMA‐GMA Copolymers
Authors: Brito Gustavo F. , Agrawal Pankaj , Mélo Tomás J. A.
Published: September 2016

In this work, the effect of Ethylene‐Glycidyl Methacrylate (E‐GMA) and Ethylene‐Methyl Acrylate‐Glycidyl Methacrylate (EMA‐GMA) copolymers on the mechanical and morphological properties on the blends of poly (lactic acid) (PLA) with biopolyethylene (BioPE) was evaluated. Uncompatibilized and compatibilized blends were prepared by extrusion followed by injection molding and characterized by Melt Flow Index (MFI), Fourier Transform Infrared Spectroscopy (FTIR), mechanical properties, Scanning (SEM) and Transmission electron microscopy (TEM). The results of mechanical tests showed that E‐GMA and EMA‐GMA copolymers acted promoting the compatibilization of the PLA/BioPE blend. MFI measurements along with FTIR and morphology analysis by SEM indicated the formation of in‐situ copolymers due to reactions between hydroxyl and carboxyl functional groups of PLA and the epoxy groups of E‐GMA and EMA‐GMA copolymers.
Preparation of Polyurethane Foams Based on Maltodextrin and Their Potential Use in Methyl Ester (Biodiesel) Purification
Authors: Kubota Tatiana , de Araújo Márcia Valéria Gaspar , de Sá Daniel Jorge Cardoso , Luneli Carlos Eduardo , Barbosa Ronilson Vasconcelos , Ramos Luiz Pereira , Zawadzki Sônia Faria
Published: September 2016

Biodiesel can be obtained by transesterification of the triglycerides present in the vegetable oil and animal fat. After the reaction it is necessary to purify the alkyl esters. One way to obtain this is making the dry wash. Thus, this study proposes the preparation of polyurethane foams with maltodextrin as sorbents for use in the biodiesel purification. The foams were prepared and characterized by ATR‐FTIR, TGA, DSC and water absorption test (ASTM D570). The FTIR spectra showed typical bands of polyurethane, TGA curves showed weight loss in two stages, the DSC analysis of the foams based on maltodextrin revealed a Tg value higher than that observed for the control foam, moreover, the absorption test in water showed that the foams based on maltodextrin showed a more hydrophilic character. The efficiency of the foams as possible sorbents for biodiesel purification was monitored by two indicators: soap concentration (AOCS Cc 17‐19) and acidity index (AOCS Ca 5a‐40). The results indicated that the foams were promising candidates in the removal of contaminants.
Evaluation of Thermal Properties of Nanocomposites Based on Ecobras Matrix and Vermiculite Modified with Alkylphosphonium Salt
Authors: Oliveira Marcelo F. L. , Braga Fernanda C. F. , Leite Márcia C. A. M. , Oliveira Marcia G.
Published: September 2016

The use of biodegradable polymers to produce nanocomposites with mineral fillers leads to the production of new materials with low cost and reduced environmental impact, combined with improvements in mechanical and thermal properties. Nanocomposites based on poly(butylene adipate‐co‐terephthalate) and starch blend (Ecobras) and vermiculite (VMT) modified with hexadecyltributylphosphonium bromide (P‐VMT) were prepared by melt intercalation in a mixing chamber at 140 °C, keeping the amount of clay at 4%wt. The intercalation of P‐VMT in Ecobras was characterized by X‐ray diffraction (XRD) and infrared spectroscopy (FTIR). VMT organophilization was confirmed by the appearance of FTIR bands characteristic of the long alkyl chain of the phosphonium salt used and also by displacement of the basal peak towards lower 2θ values in the diffractogram compared to pure vermiculite. The thermal properties of Ecobras and its compositions were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of VMT and P‐VMT in Ecobras increased the crystallization temperature (Tc) and crystalline melting temperature (Tm), as observed by DSC analysis. The result of the thermogravimetric analysis showed that the addition of P‐VMT in Ecobras improved thermal stability of the nanocomposite. The Young's modulus of the composite with 4 wt% of P‐VMT indicated an increase in stiffness compared to the pure matrix.
Preparation and Characterization of Okra Mucilage (Abelmoschus esculentus) Edible Films
Authors: de Alvarenga Pinto Cotrim Monique , Mottin Artur Caron , Ayres Eliane
Published: September 2016

Okra (Abelmoschus esculentus) is a perishable fruit with an extremely short post‐harvesting period. In the present study we have investigated the development of edible films obtained from mucilage of rejected okra fruits. The obtained okra mucilage was characterized by FTIR, percentage yield, swelling index in water, percentage solubility in water, XRD, TGA and DSC. The TGA curve has showed that okra mucilage has good thermal stability and low moisture content, which was demonstrated by the low initial mass loss. Edible films were prepared with two mucilage concentrations (1% and 1.5% w/v) combined with three plasticizer contents (PEG‐200), 0.25%, 0.50% and 0.75% v/v. The produced films were evaluated for their wettability, folding endurance, water solubility and color analysis of L*a*b color parameters. All analyses have demonstrated that plasticizer plays a key role in the system. The results obtained indicated that okra mucilage has potential to be used as edible film.
1H NMR study and multivariate data analysis of reindeer skin tanning methods
Authors: Zhu Lizheng , Ilott Andrew J. , Del Federico Eleonora , Kehlet Cindie , Klokkernes Torunn , Jerschow Alexej
Published: September 2016

Reindeer skin clothing has been an essential component in the lives of indigenous people of the arctic and sub‐arctic regions, keeping them warm during harsh winters. However, the skin processing technology, which often conveys the history and tradition of the indigenous group, has not been well documented. In this study, NMR spectra and relaxation behaviors of reindeer skin samples treated with a variety of vegetable tannin extracts, oils and fatty substances are studied and compared. With the assistance of principal component analysis (PCA), one can recognize patterns and identify groupings of differently treated samples. These methods could be important aids in efforts to conserve museum leather artifacts with unknown treatment methods and in the analysis of reindeer skin tanning processes. Copyright © 2016 John Wiley & Sons, Ltd.
PAVM: a framework for policy‐aware virtual machine management
Authors: Durrani Muhammad Nouman , Zahid Feroz , Shamsi Jawwad A.
Published: September 2016

The problem of efficient placement of virtual machines (VMs) in cloud computing infrastructure is well studied in the literature. VM placement decision involves selecting a physical machine in the data center to host a specific VM. This decision could play a pivotal role in yielding high efficiency for both the cloud and its users. Also, reallocation of VMs could be performed through migrations to achieve goals like higher server consolidation or power saving. VM placement and reallocation decisions may consider affinities such as memory sharing, CPU processing, disk sharing, and network bandwidth requirements between VMs defined in multiple dimensions. Considering the NP‐hard complexity associated with computing an optimal solution for this VM placement decision problem, existing research employs heuristic‐based techniques to compute an efficient solution. However, most of these approaches are restricted to only a single attribute at a time. That is, a given technique of using heuristics to compute VM placement considers only a single attribute, while completely ignoring the impact of other dimensions of placing VMs. While this approach may improve the efficiency with respect to the affinity attribute in consideration, it may yield degraded performance with respect to other affinities. In addition, the criteria for determining VM‐placement efficiency may vary for different applications. Hence, the overall goal of achieving VM placement efficiency becomes difficult and challenging. We are motivated by this challenging problem of efficient VM placement and propose policy‐aware virtual machine management (PAVM), a generic framework that can be used for efficient VM management in a cloud computing platform based on the service provider‐defined policies to achieve the desired system‐wide goals. This involves efficient means to profile different VM affinities and to use profiled information effectively by intelligent and efficient VM migrations at run time considering multiple attributes at a time. By conducting extensive evaluation through simulation and real experiments that involve VM affinities on the basis of network and memory, we confirmed that the PAVM architecture is capable of improving the efficiency of a cloud system. We elaborate the architecture of a PAVM system, describe its implementation, and present details of our experiments. Copyright © 2016 John Wiley & Sons, Ltd.
Implicit dynamic analysis using an isogeometric Reissner–Mindlin shell formulation
Authors: Sobota P. M. , Dornisch W. , Müller R. , Klinkel S.
Published: September 2016

In isogeometric analysis, identical basis functions are used for geometrical representation and analysis. In this work, non‐uniform rational basis splines basis functions are applied in an isoparametric approach. An isogeometric Reissner–Mindlin shell formulation for implicit dynamic calculations using the Galerkin method is presented. A consistent as well as a lumped matrix formulation is implemented. The suitability of the developed shell formulation for natural frequency analysis is demonstrated by a numerical example. In a second set of examples, transient problems of plane and curved geometries undergoing large deformations in combination with nonlinear material behavior are investigated. Via a zero‐thickness stress algorithm for arbitrary material models, a J2‐plasticity constitutive law is implemented. In the numerical examples, the effectiveness, robustness, and superior accuracy of a continuous interpolation method of the shell director vector is compared with experimental results and alternative numerical approaches. Copyright © 2016 John Wiley & Sons, Ltd.
Novel deletion in 11p15.5 imprinting center region 1 in a patient with Beckwith–Wiedemann syndrome provides insight into distal enhancer regulation and tumorigenesis
Authors: Bachmann Nadine , Crazzolara Roman , Bohne Florian , Kotzot Dieter , Maurer Kathrin , Enklaar Thorsten , Prawitt Dirk , Bergmann Carsten
Published: September 2016

Background

Beckwith–Wiedemann syndrome (BWS) is an early‐onset overgrowth disorder with a high risk for embryonal tumors. It is mainly caused by dysregulation of imprinted genes on chromosome 11p15.5; however, the driving forces in the development of tumors are not fully understood.

Procedure

We report on a female patient presenting with macrosomia, macroglossia, organomegaly and extensive bilateral nephroblastomatosis. Adjuvant chemotherapy was initiated; however, the patient developed hepatoblastoma and Wilms tumor at 5 and 12 months of age, respectively. Subsequent radiofrequency ablation of the liver tumor and partial nephrectomy followed by consolidation therapy achieved complete remission.

Results

Molecular genetic analysis revealed a maternally derived large deletion of the complete H19‐differentially methylated region (H19‐DMR; imprinting control region‐1 [ICR1]), the whole H19 gene itself as well as large parts of the distal enhancer region within the imprinting cluster‐1 (IC1). Extended analysis showed highly elevated insulin‐like growth factor 2 (IGF2) expression, possibly explaining at least in part the distinct BWS features and tumor manifestations.

Conclusions

This study of a large maternal deletion encompassing the H19 gene and complete ICR1 is the first to demonstrate transcriptional consequences on IGF2 in addition to methylation effects resulting in severe overgrowth and occurrence of multiple tumors in a BWS patient. Studying this deletion helps to clarify the complex molecular processes involved in BWS and provides further insight into tumorigenesis.
Shape memory induced structural evolution of high performance copolyimides
Authors: Yang Zenghui , Song Fuzhi , Wang Qihua , Wang Tingmei
Published: September 2016

In this work, two kinds of high temperature shape memory copolyimides were prepared and the shape memory cycles induced structural evolution of macromolecular chains was investigated in detail. The glass transition temperature (Tg) of poly(benzoxazole‐co‐imide) (PI1) and poly(benzimidazole‐co‐imide) (PI2) are 280 °C and 355 °C, respectively. The results show that PI1 could keep stable macromolecular chain structure under shape memory cycles and exhibit outstanding shape memory performance (Rf > 98%, Rr > 97%) under different stretch condition. Whereas, shape memory cycles induced orientation with more ordered macromolecular chains packing is formed for PI2 after several thermal mechanical cycles, which strongly affect physical crosslinking points, thermal mechanical properties as well as shape memory behaviors. The study on macroscopic property and microscopic structure evolution will promote a better understanding of the shape memory effect of polyimides and accelerate development of high performance polyimides for shape memory applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3858–3867
Diethynylbenzo[1,2‐b:4,5‐b′]dithiophene‐based small molecule and cross‐conjugated copolymers for organic solar cells
Authors: Xie Ruihao , Xu Rongguo , Liang Yiming , Yin Qingwu , Huang Yunping , Ying Lei , Huang Fei , Cao Yong
Published: September 2016

In this manuscript we reported the synthesis of diethynylbenzo[1,2‐b:4,5‐b′]dithiophene(DEBDT)‐based small molecule BDTTIPS and three new cross‐conjugated copolymers PBDTE‐Th, PBDTE‐FBT, and PBDTE‐DPP that consist of DEBDT unit. The thermal, optophysical, and electronic properties of these materials were systematically investigated. The small molecule BDTTIPS exhibited higher absorption coefficient than the cross‐conjugated copolymers. The LUMO/HOMO energy levels of such three cross‐conjugated copolymers were −3.74/5.51, −3.77/–5.53, and −4.02/–5.58 eV as estimated from cyclic voltammetry measurements, which were lower than that of −3.63/–5.39 eV for the small molecule BDTTIPS. Due to the unique molecular structure and electronic properties of cross‐conjugated polymers, hole mobilities of PBDTE‐Th and PBDTE‐DPP were higher than that of BDTTIPS. Photovoltaic performances were investigated by fabricating organic solar cells with the configuration of ITO/PEDOT:PSS/donor:PC61BM/Ca/Al. The small molecule chromophore BDTTIPS exhibited a power conversion efficiency of 4.19%, which was much higher than those obtained from devices based on conjugated polymers as the photoactive layer. These observations indicated that the DEBDT can be a promising building block for the construction of organic semiconducting materials for organic solar cell applications, and the rational molecular design was required for the attainment of high photovoltaic performances. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 660–671
Understanding the Compatibility of the Energetic Binder PolyNIMMO with Energetic Plasticizers: Experimental and DFT Studies
Authors: Shee Sujit Kumar , Shah Priya Nitin , Athar Javaid , Dey Abhijit , Soman R. R. , Sikder Arun Kanti , Pawar Suman , Banerjee Shaibal
Published: September 2016

The development of energetic binders with suitable energetic plasticizers is required to enhance the mechanical properties and to reduce the glass transition temperature of propellant and explosive formulations. The compatibility of the energetic binder poly(3‐nitratomethyl‐3‐methyloxetane) (polyNIMMO) with five different energetic plasticizers viz. bis(2,2‐dinitro propyl)acetal (BDNPA), dinitro‐diaza‐alkanes (DNDA‐57), 1,2,4‐butanetriol trinitrate (BTTN), N‐N‐butyl‐N‘(2‐nitroxy‐ethyl) nitramine (BuNENA) and diethyleneglycoldinitrate (DEGDN) was studied by differential scanning calorimetry (DSC), rheology, and DFT methods. The results obtained for the pure binder were compared with the results obtained for the binder/plasticizer blend in regard of the decomposition temperature and the format of the peak indicated the compatibility of polyNIMMO with the plasticizers. The glass transition temperatures of the blends were determined by low temperature DSC and showed desirable lowering of glass transition temperature with single peak. The rheological evaluation revealed that the viscosity of the binder is considerably lowered by means of flow behavior upon addition of 20 % (w/w) plasticizer. The addition of BuNENA and DEGDN has maximum effect on the lowering of viscosity of polyNIMMO. The predicted relative trend of interaction energies between plasticizer and binder is well correlated with the corresponding trend of viscosity of binder/plasticizer blends. These experimental studies verified by theoretical methods are valuable to design practical blends of new plasticizers and binders.
Evaluation of a novel PXR‐knockout in HepaRG™ cells
Authors: Williamson Beth , Lorbeer Mathias , Mitchell Michael D. , Brayman Timothy G. , Riley Robert J.
Published: September 2016

The nuclear pregnane X receptor (PXR) regulates the expression of genes involved in the metabolism, hepatobiliary disposition, and toxicity of drugs and endogenous compounds. PXR is a promiscuous nuclear hormone receptor (NHR) with significant ligand and DNA‐binding crosstalk with the constitutive androstane receptor (CAR); hence, defining the precise role of PXR in gene regulation is challenging. Here, utilising a novel PXR‐knockout (KO) HepaRG cell line, real‐time PCR analysis was conducted to determine PXR involvement for a range of inducers. The selective PXR agonist rifampicin, a selective CAR activator, 6‐(4‐chlorophenyl)imidazo[2,1‐b][1,3]thiazole‐5‐carbaldehyde O‐(3,4‐dichlorobenzyl)oxime (CITCO), and dual activators of CAR and PXR including phenobarbital (PB) were analyzed. HepaRG control cells (5F clone) were responsive to prototypical inducers of CYP2B6 and CYP3A4. No response was observed in the PXR‐KO cells treated with rifampicin. Induction of CYP3A4 by PB, artemisinin, and phenytoin was also much reduced in PXR‐KO cells, while the response to CITCO was maintained. This finding is in agreement with the abolition of functional PXR expression. The apparent EC50 values for PB were in agreement between the cell lines; however, CITCO was ~threefold (0.3 μmol/L vs. 1 μmol/L) lower in the PXR‐KO cells compared with the 5F cells for CYP2B6 induction. Results presented support the application of the novel PXR‐KO cells in the definitive assignment of PXR‐mediated CYP2B6 and CYP3A4 induction. Utilization of such cell lines will allow advancement in composing structure activity relationships rather than relying predominantly on pharmacological manipulations and provide in‐depth mechanistic evaluation.
Combined thermionic and field emission reverse current for ideal graphene/n‐Si Schottky contacts in a modified Landauer formalism
Authors: Varonides Argyrios
Published: September 2016

Fundamental understanding of carrier transport is needed for current graphene‐based devices (e.g. graphene based Schottky diodes, FET geometries, solar cells) involving single layer graphene grown directly over n‐ or p‐ type semiconductors. In an intimate (ideal) G/n‐Si junction under reverse bias, carriers may (a) tunnel through the junction and/or (b) thermionically overcome the junction barrier. Tunneling occurring at the junction is in essence thermionic field emission of carriers with energy levels below the junction barrier, with a less‐than‐one tunneling probability; thermal escape may occur as long as carriers have sufficient energy to overcome the barrier at the interface. The total current is expected to be the sum of two current components, thermionic emission (TE) and thermionic field emission (TFE), respectively, representing carriers surmounting and tunneling through the barrier, in the form I = ITE + ITFE, and is strongly dependent on temperature and doping. Specifically, we derive explicit results for both currents within the general Schottky diode current‐voltage characteristic: I = Io (eqV/kT–1). The combined current prefactor includes strong dependencies on (a) temperature as T3/2 and T5/2 for TE and TFE components, respectively, (b) junction barrier qΦB, (c) graphene layer thickness δ and (d) different Richardson constants for both components. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)