bluuebunny/crossref_metadata_2025 huggingface dataset:
On the gEUD biological optimization objective for organs at risk in Photon Optimizer of Eclipse treatment planning system
Authors: Fogliata Antonella , Thompson Stephen , Stravato Antonella , Tomatis Stefano , Scorsetti Marta , Cozzi Luca
Published: November 2017

Inverse planning optimization using biologically based objectives is becoming part of the intensity modulated optimization process. The performances and efficacy of the biologically based gEUD (generalized Equivalent Uniform Dose) objective implemented in the Photon Optimizer (PO) of Varian Eclipse treatment planning system have been here analyzed. gEUD is associated with the parameter a that accounts for the seriality of a structure, being higher for more serial organs. The PO was used to optimize volumetric modulated arc therapy (VMAT) plans on a virtual homogeneous cylindrical phantom presenting a target and an organ at risk (OAR). The OAR was placed at 4 mm, 1 and 2 cm distance, or cropped at 0, 2 and 4 mm from the target. Homogeneous target dose of 60 Gy in 20 fractions was requested with physical dose‐volume objectives, while OAR dose was minimized with the upper gEUD objective. The gEUD specific a parameter was varied from 0.1 to 40 to assess its impact to OAR sparing and target coverage. Actual head and neck and prostate cases, with one parotid and the rectum as test OAR, were also analyzed to translate the results in the more complex clinical environment. Increasing the a parameter value in the gEUD objective, the optimization achieved lower volumes of the OAR which received the highest dose levels. The maximum dose in the OAR was minimized well with a values up to 20, while further increase of a to 40 did not further improve the result. The OAR mean dose was reduced for the OAR located at 1 and 2 cm distance from the target, enforced with increasing a. For cropped OARs, a mean dose reduction was achieved for a values up to 3–5, but mean dose increased for higher a values. The optimal choice of the parameter a depends on the mutual OAR and target position, and seriality of the organ. Today no significant compendium of clinical and biological specific a and gEUD values are available for a wide range of OARs.
Commissioning of the world's first compact pencil‐beam scanning proton therapy system
Authors: Pidikiti Rajesh , Patel Bijal C. , Maynard Matthew R. , Dugas Joseph P. , Syh Joseph , Sahoo Narayan , Wu Hsinshun Terry , Rosen Lane R.
Published: November 2017

This paper summarizes clinical commissioning of the world's first commercial, clinically utilized installation of a compact, image‐guided, pencil‐beam scanning, intensity‐modulated proton therapy system, the IBA Proteus®ONE, at the Willis‐Knighton Cancer Center (WKCC) in Shreveport, LA. The Proteus®ONE is a single‐room, compact‐gantry system employing a cyclotron‐generated proton beam with image guidance via cone‐beam CT as well as stereoscopic orthogonal and oblique planar kV imaging. Coupling 220° of gantry rotation with a 6D robotic couch capable of in plane patient rotations of over 180° degrees allows for 360° of treatment access. Along with general machine characterization, system commissioning required: (a) characterization and calibration of the proton beam, (b) treatment planning system commissioning including CT‐to‐density curve determination, (c) image guidance system commissioning, and (d) safety verification (interlocks and radiation survey). System readiness for patient treatment was validated by irradiating calibration TLDs as well as prostate, head, and lung phantoms from the Imaging and Radiation Oncology Core (IROC), Houston. These results confirmed safe and accurate machine functionality suitable for patient treatment. WKCC also successfully completed an on‐site dosimetry review by an independent team of IROC physicists that corroborated accurate Proteus®ONE dosimetry.
Tolerance levels of CT number to electron density table for photon beam in radiotherapy treatment planning system
Authors: Nakao Minoru , Ozawa Shuichi , Yamada Kiyoshi , Yogo Katsunori , Hosono Fumika , Hayata Masahiro , Saito Akito , Miki Kentaro , Nakashima Takeo , Ochi Yusuke , Kawahara Daisuke , Morimoto Yoshiharu , Yoshizaki Toru , Nozaki Hiroshige , Habara Kosaku , Nagata Yasushi
Published: November 2017

The accuracy of computed tomography number to electron density (CT‐ED) calibration is a key component for dose calculations in an inhomogeneous medium. In a previous work, it was shown that the tolerance levels of CT‐ED calibration became stricter with an increase in tissue thickness and decrease in the effective energy of a photon beam. For the last decade, a low effective energy photon beam (e.g., flattening‐filter‐free (FFF)) has been used in clinical sites. However, its tolerance level has not been established yet. We established a relative electron density (ED) tolerance level for each tissue type with an FFF beam. The tolerance levels were calculated using the tissue maximum ratio (TMR) and each corresponding maximum tissue thickness. To determine the relative ED tolerance level, TMR data from a Varian accelerator and the adult reference computational phantom data in the International Commission on Radiological Protection publication 110 (ICRP‐110 phantom) were used in this study. The 52 tissue components of the ICRP‐110 phantom were classified by mass density as five tissues groups including lung, adipose/muscle, cartilage/spongy‐bone, cortical bone, and tooth tissue. In addition, the relative ED tolerance level of each tissue group was calculated when the relative dose error to local dose reached 2%. The relative ED tolerances of a 6 MVFFF beam for lung, adipose/muscle, and cartilage/spongy‐bone were ±0.044, ±0.022, and ±0.044, respectively. The thicknesses of the cortical bone and tooth groups were too small to define the tolerance levels. Because the tolerance levels of CT‐ED calibration are stricter with a decrease in the effective energy of the photon beam, the tolerance levels are determined by the lowest effective energy in useable beams for radiotherapy treatment planning systems.
Analysis of Optical Losses in a Photoelectrochemical Cell: A Tool for Precise Absorptance Estimation
Authors: Cendula Peter , Steier Ludmilla , Losio Paolo A. , Grätzel Michael , Schumacher Jürgen O.
Published: November 2017

Optical losses in a photoelectrochemical (PEC) cell account for a substantial part of solar‐to‐hydrogen conversion losses, but limited attention is paid to the detailed investigation of optical losses in PEC cells. In this work, an optical model of combined coherent and incoherent light propagation in all layers of the PEC cell based on spectroscopic measurements is presented. Specifically, photoelectrodes using transparent conductive substrates such as F:SnO2 coated with thin absorber films are focused. The optical model is verified for hematite photoanodes fabricated by atomic layer deposition and successfully used to determine wavelength‐dependent reflection, transmission, layer absorptances, and charge generation rates. Furthermore, the calculated absorptances enable 20–30% more accurate calculations of the absorbed photon‐to‐current efficiency of PEC cells. Our optical model is a powerful tool for the optimization of the optical performance of PEC cells focusing on single absorber or tandem configurations and represents a cornerstone of a complete (optical and electrical) model for PEC water splitting cells.
Influence of Radiation on the Properties and the Stability of Hybrid Perovskites
Authors: Lang Felix , Shargaieva Oleksandra , Brus Viktor V. , Neitzert Heinz C. , Rappich Jörg , Nickel Norbert H.
Published: November 2017

Organic–inorganic perovskites are well suited for optoelectronic applications. In particular, perovskite single and perovskite tandem solar cells with silicon are close to their market entry. Despite their swift rise in efficiency to more than 21%, solar cell lifetimes are way below the needed 25 years. In fact, comparison of the time when the device performance has degraded to 80% of its initial value (T80 lifetime) of numerous solar cells throughout the literature reveals a strongly reduced stability under illumination. Herein, the various detrimental effects are discussed. Most notably, moisture‐ and heat‐related degradation can be mitigated easily by now. Recently, however, several photoinduced degradation mechanisms have been observed. Under illumination, mixed perovskites tend to phase segregate, while, further, oxygen catalyzes deprotonation of the organic cations. Additionally, during illumination photogenerated charge can be trapped in the NH antibonding orbitals causing dissociation of the organic cation. On the other hand, organic–inorganic perovskites exhibit a high radiation hardness that is superior to crystalline silicon. Here, the proposed degradation mechanisms reported in the literature are thoroughly reviewed and the microscopic mechanisms and their implications for solar cells are discussed.
Strong Coupling in a Photonic Molecule Formed by Trapping a Microsphere in a Microtube Cavity
Authors: Wang Jiawei , Yin Yin , Hao Qi , Zhang Yang , Ma Libo , Schmidt Oliver G.
Published: November 2017

A photonic molecule formed by trapping a microsphere cavity into a hollow microtube cavity is demonstrated, which provides a novel design over conventional photonic molecules comprised of solid‐core whispering gallery mode microcavities with externally tangent configuration. Periodic spectral modulations of mode intensity, resonant mode shift, and quality factor are observed owing to the largely mismatched cavity sizes. The intercavity coupling strength can be tuned by shifting the excitation position off the tangent point of the microsphere‐tube system along the tube axis, rather than the conventional strategy of changing the spacing between coupled cavities. In particular, anticrossing feature of coupled modes is revealed to verify the existence of optical strong coupling in the microsphere‐tube system. Numerical simulation results show an excellent agreement with the experimental observations. The present work provides a flexible strategy for designing photonic molecules and tuning the coupling behavior of resonant modes, which is of high interest for both fundamental and applied studies.
Environmental TEM Investigation of Electrochemical Stability of Perovskite and Ruddlesden–Popper Type Manganite Oxygen Evolution Catalysts
Authors: Mierwaldt Daniel , Roddatis Vladimir , Risch Marcel , Scholz Julius , Geppert Janis , Abrishami Majid Ebrahimizadeh , Jooss Christian
Published: November 2017

The sluggish kinetics of the oxygen evolution reaction (OER) is a grand challenge for energy storage technologies. Several perovskites and other oxides of earth‐abundant elements are found to exhibit improved catalytic OER activity. However, less attention is paid to the electrochemical stability, an important factor for large‐scale application. The ongoing search for stable catalysts calls for characterizing active catalyst surfaces and identifying mechanisms of deactivation, activation, or repair. In situ techniques are indispensable for these tasks. This study uses environmental transmission electron microscopy on the highly correlated perovskite Pr1–xCaxMnO3 and the Ruddlesden–Popper Pr0.5Ca1.5MnO4 as model electrodes to elucidate the underlying mechanisms of the stability trends identified on rotating ring disk electrodes. An electron beam at fluxes well below those that would cause radiation damage is used to induce positive local electrode potentials due to secondary electron emission, driving electrochemical reactions in H2O vapor. The stability of the model systems increases with increasing ionic character of the MnO bond, while more covalent bonds are prone to corrosion, which is triggered by formation of point defects in the oxygen sublattice.
Lead‐Free Hybrid Perovskite Absorbers for Viable Application: Can We Eat the Cake and Have It too?
Authors: Liang Lusheng , Gao Peng
Published: November 2017

Many years since the booming of research on perovskite solar cells (PSCs), the hybrid perovskite materials developed for photovoltaic application form three main categories since 2009: (i) high‐performance unstable lead‐containing perovskites, (ii) low‐performance lead‐free perovskites, and (iii) moderate performance and stable lead‐containing perovskites. The search for alternative materials to replace lead leads to the second group of perovskite materials. To date, a number of these compounds have been synthesized and applied in photovoltaic devices. Here, lead‐free hybrid light absorbers used in PV devices are focused and their recent developments in related solar cell applications are reviewed comprehensively. In the first part, group 14 metals (Sn and Ge)‐based perovskites are introduced with more emphasis on the optimization of Sn‐based PSCs. Then concerns on halide hybrids of group 15 metals (Bi and Sb) are raised, which are mainly perovskite derivatives. At the same time, transition metal Cu‐based perovskites are also referred. In the end, an outlook is given on the design strategy of lead‐free halide hybrid absorbers for photovoltaic applications. It is believed that this timely review can represent our unique view of the field and shed some light on the direction of development of such promising materials.
Modified Back Contact Interface of CZTSe Thin Film Solar Cells: Elimination of Double Layer Distribution in Absorber Layer
Authors: Zhang Zhaojing , Yao Liyong , Zhang Yi , Ao Jianping , Bi Jinlian , Gao Shoushuai , Gao Qing , Jeng Ming‐Jer , Sun Guozhong , Zhou Zhiqiang , He Qing , Sun Yun
Published: November 2017

Double layer distribution exists in Cu2SnZnSe4 (CZTSe) thin films prepared by selenizing the metallic precursors, which will degrade the back contact of Mo substrate to absorber layer and thus suppressing the performance of solar cell. In this work, the double‐layer distribution of CZTSe film is eliminated entirely and the formation of MoSe2 interfacial layer is inhibited successfully. CZTSe film is prepared by selenizing the precursor deposited by electrodeposition method under Se and SnSex mixed atmosphere. It is found that the insufficient reaction between ZnSe and Cu‐Sn‐Se phases in the bottom of the film is the reason why the double layer distribution of CZTSe film is formed. By increasing Sn content in the metallic precursor, thus making up the loss of Sn because of the decomposition of CZTSe and facilitate the diffusion of liquid Cu2Se, the double layer distribution is eliminated entirely. The crystallization of the formed thin film is dense and the grains go through the entire film without voids. And there is no obvious MoSe2 layer formed between CZTSe and Mo. As a consequence, the series resistance of the solar cell reduces significantly to 0.14 Ω cm2 and a CZTSe solar cell with efficiency of 7.2% is fabricated.
Assessing consumers’ preferences and willingness to pay for novel sliced packed fresh pears: A latent class approach
Authors: Ikiz Dila , Gallardo R. Karina , Dhingra Amit , Hewitt Seanna
Published: November 2017

The North American fresh pear industry faces marketing challenges that could jeopardize its’ long‐term economic profitability. The production of sliced fresh pears is a promising alternative to overcome the lack of supplying consistently a product with superior quality with added convenience, potentially able to increase domestic consumption. In this paper, we used sensory evaluation and a Vickrey experimental auction to elicit consumers’ preferences and willingness to pay for sliced packed fresh pears treated with SmartFresh™ (1‐methylcyclopropene) and subsequently with a ripening compound (RC) in the form of glyoxylic acid at different concentration levels (1%, 2%, 3%, and control). Panelists were willing to pay a price premium equivalent to $0.119/2 oz packet for the 2% RC sample, $0.055/2 oz packet for the 3% RC sample, and $0.025/2 oz packet for the 1% RC sample compared to the control sample. Results from a market segmentation analyses indicate the presence of two groups in the panelist sample. The group that liked sliced pears assigned higher importance to locally grown fruit and price, shopped at conventional retailer grocery stores, had fewer children in the household, and were younger compared to the group that disliked sliced pears. [EconLit citation: Q13].
Combining sensory evaluations and experimental auctions to assess consumers’ preferences for fresh fruit quality characteristics
Authors: Gallardo R. Karina , Hanrahan Ines , Yue Chengyan , McCracken Vicki A. , Luby James , McFerson James R. , Ross Carolyn , Carrillo‐Rodriguez Lilian
Published: November 2017

A combination of sensory evaluation and experimental auctions was used to analyze consumer preferences for external and internal quality characteristics of two fresh apple varieties “Honeycrisp” and “Gala.” A group of 384 panelists in three locations in the United States evaluated the appearance, the internal quality characteristics, in three sequential rounds, for the two apple variety samples. Each panelist responded to a sensory evaluation questionnaire, and then bid on the samples in an incentive compatible second price auction. We found that panelists’ bids increased with the amount of information given. Also, we found that for some attributes such as sweetness, panelists preferred levels closer to their ideal rather than objectively measured higher levels. When evaluating consumers’ preference and valuation for different fresh fruit varieties, a greater explanatory power is obtained when including an indicator variable for the variety along with the set of quality attributes. The indicator variable could improve the control of inherent factors related with the varieties but cannot be observed or inferred easily. Finally, our findings add to previous studies in that flavor, when expressed as a combination of sweetness and acidity in addition to textural attributes, are important determinants of consumers’ acceptance. [EconLit citations: Q13]
For the Good of the Group? Balancing Individual and Collective Risks and Benefits in Community Psychology Research
Authors: Dworkin Emily R. , Allen Nicole E.
Published: November 2017

Highlights

Research risks and benefits are typically considered in relation to individual research participants.

Research may also involve risks and benefits to contexts such as groups, systems, and society.

We discuss strategies for balancing individual and contextual risks/benefits using a case example.

We explain how risks and benefits can be analogous across levels of analysis.

We demonstrate how changing risks/benefits at one level affects risks/benefits at other levels.
Community Data Collection with Children of Mothers Living withHIV: Boundaries of the Researcher Role
Authors: LeCroix Rebecca Hill , Goodrum Nada M. , Hufstetler Schell , Armistead Lisa P.
Published: November 2017

Highlights

Describes experiences of depression by mothers living with HIV and their children.

Provides vignette compilation to illustrate the ways in which children have expressed depression.

Suggests ways that researchers conduct ethical and thorough risk assessment to provide resources.

Describes how community psychology values influence boundaries and ethics of researchers.
Valuing Our Communities: Ethical Considerations for Economic Evaluation of Community‐Based Prevention
Authors: Crowley Max , Jones Damon
Published: November 2017

Restricted public budgets and increasing efforts to link the impact of community interventions to public savings have increased the use of economic evaluation. While this type of evaluation can be important for program planning, it also raises important ethical issues about how we value the time of local stakeholders who support community interventions. In particular, researchers navigate issues of scientific accuracy, institutional inequality, and research utility in their pursuit of even basic cost estimates. We provide an example of how we confronted these issues when estimating the costs of a large‐scale community‐based intervention. Principles for valuing community members’ time and conducting economic evaluations of community programs are discussed.
Estimation of minimal disease prevalence from population genomic data: Application to primary familial brain calcification
Authors: Nicolas Gaël , Charbonnier Camille , Campion Dominique , Veltman Joris A.
Published: November 2017

Primary Familial Brain Calcification (PFBC) is a rare calcifying disorder of the brain with autosomal dominant inheritance, of unknown prevalence. Four causal genes have been identified so far: SLC20A2, PDGFB, PDGFRB, and XPR1, with pathogenic, probably pathogenic or missense variants of unknown significance found in 27.7% probands in the French PFBC series. Estimating PFBC prevalence from a clinical input is arduous due to a large diversity of symptoms and ages of onset and to incomplete clinical penetrance. Abnormal calcifications on CT scan can be used as a reliable diagnostic biomarker whatever the clinical status, but differential diagnoses should be ruled out including the challenging exclusion of common basal ganglia calcifications. Our primary aim was to estimate the minimal prevalence of PFBC due to a variant in one of the known genes. We extracted variants from the four known genes present in the gnomAD database gathering genomic data from 138,632 individuals. We interpreted all variants based on their predicted effect, their frequency, and previous studies on PFBC patients. Using the most conservative estimate, the minimal prevalence of PFBC related to a variant in one of the four known genes was 4.5 p. 10,000 (95%CI [3.4–5.5] p. 10,000). We then used variant detection rates in patients to extrapolate an overall minimal prevalence of PFBC to 2.1 p. 1,000 (95%CI [1.9–2.4] p. 1,000). The population‐based genomic analysis indicates that PFBC is not an exceptionally rare disorder, still underestimated and underdiagnosed.
Association of IMMP2L deletions with autism spectrum disorder: A trio family study and meta‐analysis
Authors: Zhang Yanqing , Liu Yi , Zarrei Mehdi , Tong Winnie , Dong Rui , Wang Ying , Zhang Haiyan , Yang Xiaomeng , MacDonald Jeffrey R. , Uddin Mohammed , Scherer Stephen W. , Gai Zhongtao
Published: November 2017

IMMP2L, the gene encoding the inner mitochondrial membrane peptidase subunit 2‐like protein, has been reported as a candidate gene for Tourette syndrome, autism spectrum disorder (ASD) and additional neurodevelopmental disorders. Here we genotyped 100 trio families with an index proband with autism spectrum disorder in Han Chinese population and found three cases with rare exonic IMMP2L deletions. We have conducted a comprehensive meta‐analysis to quantify the association of IMMP2L deletions with ASD using 5,568 cases and 10,279 controls. While the IMMP2L deletions carried non‐recurrent breakpoints, in contrast to previous reports, our meta‐analysis found no evidence of association (P > 0.05) between IMMP2L deletions and ASD. We also observed common exonic deletions impacting IMMP2L in a separate control (5,971 samples) cohort where subjects were screened for psychiatric conditions. This is the first systematic review and meta‐analysis regarding the effect of IMMP2L deletions on ASD, but further investigations in different populations, especially Chinese population may be still needed to confirm our results.
Additive genetic variation in the craniofacial skeleton of baboons (genus Papio) and its relationship to body and cranial size
Authors: Joganic Jessica L. , Willmore Katherine E. , Richtsmeier Joan T. , Weiss Kenneth M. , Mahaney Michael C. , Rogers Jeffrey , Cheverud James M.
Published: November 2017

Objectives

Determining the genetic architecture of quantitative traits and genetic correlations among them is important for understanding morphological evolution patterns. We address two questions regarding papionin evolution: (1) what effect do body and cranial size, age, and sex have on phenotypic (VP) and additive genetic (VA) variation in baboon crania, and (2) how might additive genetic correlations between craniofacial traits and body mass affect morphological evolution?

Materials and Methods

We use a large captive pedigreed baboon sample to estimate quantitative genetic parameters for craniofacial dimensions (EIDs). Our models include nested combinations of the covariates listed above. We also simulate the correlated response of a given EID due to selection on body mass alone.

Results

Covariates account for 1.2–91% of craniofacial VP. EID VA decreases across models as more covariates are included. The median genetic correlation estimate between each EID and body mass is 0.33. Analysis of the multivariate response to selection reveals that observed patterns of craniofacial variation in extant baboons cannot be attributed solely to correlated response to selection on body mass, particularly in males.

Discussion

Because a relatively large proportion of EID VA is shared with body mass variation, different methods of correcting for allometry by statistically controlling for size can alter residual VP patterns. This may conflate direct selection effects on craniofacial variation with those resulting from a correlated response to body mass selection. This shared genetic variation may partially explain how selection for increased body mass in two different papionin lineages produced remarkably similar craniofacial phenotypes.
Predicting the bending properties of long bones: Insights from an experimental mouse model
Authors: Peacock Sarah J. , Coats Brittney R. , Kirkland J. Kyle , Tanner Courtney A. , Garland Theodore , Middleton Kevin M.
Published: November 2017

Objectives

Analyses of bone cross‐sectional geometry are frequently used by anthropologists and paleontologists to infer the loading histories of past populations. To address some underlying assumptions, we investigated the relative roles of genetics and exercise on bone cross‐sectional geometry and bending mechanics in three mouse strains: high bone density (C3H/He), low bone density (C57BL/6), and a high‐runner strain homozygous for the Myh4Minimsc allele (MM).

Methods and Materials

Weanlings of each strain were divided into exercise (wheel) or control (sedentary) treatment groups for a 7‐week experimental period. Morphometrics of the femoral mid‐diaphysis and mechanical testing were used to assess both theoretical and ex vivo bending mechanics.

Results

Across all measured morphological and bending traits, we found relatively small effects of exercise treatment compared to larger and more frequent interstrain differences. In the exercised group, total distance run over the experimental period was not a predictor of any morphological or bending traits. Cross‐sectional geometry did not accurately predict bone response to loading.

Discussion

Results from this experimental model do not support hypothesized associations among extreme exercise, cross‐sectional geometry, and bending mechanics. Our results suggest that analysis of cross‐sectional geometry alone is insufficient to predict loading response, and questions the common assumption that cross‐sectional geometry differences are indicative of differential loading history.
Iron(II)‐Catalyzed Direct Synthesis of NH Sulfoximines from Sulfoxides
Authors: Yu Hao , Li Zhen , Bolm Carsten
Published: November 2017

Free NH‐sulfoximines were directly prepared from sulfoxides through iron catalysis by applying a readily available, shelf‐stable hydroxylamine triflic acid salt. No additional oxidant is needed, and the substrate scope is broad, including a range of heterocyclic compounds.
Catalytic Dibenzocyclooctene Synthesis via Cobalt(III)–Carbene Radical and ortho‐Quinodimethane Intermediates
Authors: te Grotenhuis Colet , van den Heuvel Naudin , van der Vlugt Jarl Ivar , de Bruin Bas
Published: November 2017

The metalloradical activation of ortho‐benzallylaryl N‐tosyl hydrazones with [Co(TPP)] (TPP=tetraphenylporphyrin) as the catalyst enabled the controlled exploitation of the single‐electron reactivity of the redox non‐innocent carbene intermediate. This method offers a novel route to prepare eight‐membered rings, using base metal catalysis to construct a series of unique dibenzocyclooctenes through selective Ccarbene−Caryl cyclization. The desired eight‐membered‐ring products were obtained in good to excellent yields. A large variety of aromatic substituents are tolerated. The proposed reaction mechanism involves intramolecular hydrogen atom transfer (HAT) to CoIII–carbene radical intermediates followed by dissociation of an ortho‐quinodimethane that undergoes 8π cyclization. The mechanism is supported by DFT calculations, and the presence of radical‐type intermediates was confirmed by trapping experiments.
Mono‐ and Bis(imidazolidinium ethynyl) Cations and Reduction of the Latter To Give an Extended Bis‐1,4‐([3]Cumulene)‐p‐carboquinoid System
Authors: Barry Brian M. , Soper R. Graeme , Hurmalainen Juha , Mansikkamäki Akseli , Robertson Katherine N. , McClennan William L. , Veinot Alex J. , Roemmele Tracey L. , Werner‐Zwanziger Ulrike , Boeré René T. , Tuononen Heikki M. , Clyburne Jason A. C. , Masuda Jason D.
Published: November 2017

An extended π‐system containing two [3]cumulene fragments separated by a p‐carboquinoid and stabilized by two capping N‐heterocyclic carbenes (NHCs) has been prepared. Mono‐ and bis(imidazolidinium ethynyl) cations have also been synthesized from the reaction of an NHC with phenylethynyl bromide or 1,4‐bis(bromoethynyl)benzene. Cyclic voltammetry coupled with synthetic and structural studies showed that the dication is readily reduced to a neutral, singlet bis‐1,4‐([3]cumulene)‐p‐carboquinoid as a result of the π‐accepting properties of the capping NHCs.
Nanoscale Trimetallic Metal–Organic Frameworks Enable Efficient Oxygen Evolution Electrocatalysis
Authors: Li Fei‐Long , Shao Qi , Huang Xiaoqing , Lang Jian‐Ping
Published: November 2017

Metal–organic frameworks (MOFs) are a class of promising materials for diverse heterogeneous catalysis, but they are usually not directly employed for oxygen evolution electrocatalysis. Most reports focus on using MOFs as templates to in situ create efficient electrocatalysts through annealing. Herein, we prepared a series of Fe/Ni‐based trimetallic MOFs (Fe/Ni/Co(Mn)‐MIL‐53 accordingly to the Material of Institute Lavoisier) by solvothermal synthesis, which can be directly adopted as highly efficient electrocatalysts. The Fe/Ni/Co(Mn)‐MIL‐53 shows a volcano‐type oxygen evolution reaction (OER) activity as a function of compositions. The optimized Fe/Ni2.4/Co0.4‐MIL‐53 can reach a current density of 20 mA cm−2 at low overpotential of 236 mV with a small Tafel slope of 52.2 mV dec−1. In addition, the OER performance of these MOFs can be further enhanced by directly being grown on nickel foam (NF).
Paleo‐inspired Systems: Durability, Sustainability, and Remarkable Properties
Authors: Bertrand Loïc , Gervais Claire , Masic Admir , Robbiola Luc
Published: November 2017

The process of mimicking properties of specific interest (such as mechanical, optical, and structural) observed in ancient and historical systems is designated here as paleo‐inspiration. For instance, recovery in archaeology or paleontology identifies materials that are a posteriori extremely resilient to alteration. All the more encouraging is that many ancient materials were synthesized in soft chemical ways, often using low‐energy resources and sometimes rudimentary manufacturing equipment. In this Minireview, ancient systems are presented as a source of inspiration for innovative material design in the Anthropocene.
Synthesis and Reactivity of Nickel‐Stabilised μ2:η2,η2‐P2, As2 and PAs Units
Authors: Hierlmeier Gabriele , Hinz Alexander , Wolf Robert , Goicoechea Jose M.
Published: November 2017

The reactivity of two paramagnetic nickel(I) compounds, CpNi(NHC) (where Cp=cyclopentadienyl; NHC=1,3‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene (IMes) or 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr)), towards [Na(dioxane)x][PnCO] (Pn=P, As) is described. These reactions afford symmetric bimetallic compounds (μ2:η2,η2‐Pn2){Ni(NHC)(CO)}2. Several novel intermediates en route to such species are identified and characterised, including a compound containing the PCO− anion in an unprecedented μ2:η2,η2‐binding mode. Ultimately, on treatment of the (μ2:η2,η2‐Pn2){Ni(IMes)(CO)}2 compounds with carbon monoxide, the Pn2 units can be released, affording P4 in the case of the phosphorus‐containing species, and elemental arsenic in the case of (μ2:η2,η2‐As2){Ni(IMes)(CO)}2.
Toward poly(furfuryl alcohol) applications diversification: Novel self‐healing network and toughening epoxy–novolac resin
Authors: Moazzen Khadijeh , Zohuriaan‐Mehr Mohammad Jalal , Jahanmardi Reza , Kabiri Kourosh
Published: November 2017

Poly(furfuryl alcohol) bioresin (PFA) was synthesized and utilized through two distinct alloying strategies. It was crosslinked by a bismaleimide (BMI) via a Diels–Alder (DA) reaction. The novel PFA–BMI polyadduct network was spectrally, thermally, and thermo‐mechanically characterized and its thermally repeatable self‐healing behavior was visually established. The network showed a high pyrolytic thermostability (char yield ∼51% at 600 °C). PFA was also used for modification of epoxy–novolac resin (EP). EP hybrid resins containing 5, 10, and 15 wt % of PFA were cured by a polyamine hardener. Despite of different curing mechanisms of the two resins, PFA had no effect on EP curing behavior as revealed by differential scanning calorimetry, which proved homogeneous formation of the thermosets. PFA at the composition of 15 wt % improved tensile properties and toughness of EP, so that it almost doubled tensile modulus and elongation at break. However, PFA slightly deteriorated flexural properties of EP. PFA also decreased Tg of EP, with a maximum decrease of 22 °C. Besides, PFA disfavored initial thermostability of EP, but improved its pyrolytic char yield. In conclusion, PFA can be beneficial from smart materials to toughen hybrid epoxy thermosets with potential applications in composites, adhesives, and surface coatings. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45921.
Enhancement of char‐forming and water resistance on ABS modified by poly(4‐nitrophenoxy)‐phosphazene
Authors: Yang Yunyun , Kong Weibo , Luo Hang , Cao Xilei , Cai Xufu
Published: November 2017

Poly(4‐nitrophenoxy)‐phosphazene (DPP) was used as charring and water resistance agent in Acrylonitrile–butadiene–styrene (ABS) composites. The char‐forming capability of DPP and combustion behavior of DPP‐based ABS (ABS‐DPP) were studied by thermogravimetric analysis (TGA) and cone calorimeter, respectively. TGA‐coupled Fourier transform infrared (TGA/FTIR) was used to research the releasing intensity of gaseous products during decomposition. Moreover, the char formation morphology of ABS, DPP, and ABS‐DPP were observed by scanning electron microscopy analysis. The water resistance of DPP was measured by the boiled water tests, the FTIR and static water contact angle analysis. The flame properties of samples and the samples treated by boiled water were studied by LOI and UL‐94, and the tensile properties of ABS‐DPP samples were assessed by tensile testing at high temperature. The results showed that the residues yield of ABS‐DPP samples increased from 0 to more than 20% under nitrogen and from 0.7 to 3.9% under air compared with pure ABS. The combustibility of ABS was decreased by DPP; however, the water resistance of ABS was not affected. At high temperature, tensile strength of ABS‐DPP decreased and the elongation at break enhanced with the addition of DPP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45988.
Solid lipid nanoparticles loaded thermoresponsive pluronic–xanthan gum hydrogel as a transdermal delivery system
Authors: Lee Min Hyeock , Shin Gye Hwa , Park Hyun Jin
Published: November 2017

The aim of this study was to develop and investigate thermoresponsive hydrogel incorporating curcumin (Cur) for application as a transdermal delivery system. Cur was encapsulated within solid lipid nanoparticles via ultrasonic homogenization, and these were introduced into a thermoresponsive hydrogel composed of pluronic F68 (PF68) and F127 (PF127). The hydrogel composed of PF68 and PF127 in 10:90 ratio transformed from sol to gel at 29.3 °C close to skin temperature. The skin adhesiveness and adhesive strength of the hydrogel with 0.2% (w/w) of XG was 1.64 and 1.24 times higher than those of the hydrogel without XG, respectively. The physiochemical characteristics of prepared formulations were investigated via observation of particle size, polydispersity index, transmission electron microscopy, and scanning electron microscopy. Moreover, Fourier transform infrared spectroscopy analysis was performed at physiological temperature, which revealed lower hydrogen bonding intensity at gel phase than at sol phase. The cumulative amount of Cur that penetrated significantly increased compared with the Cur ethanol solution. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46004.
Thermo‐mechanical behavior of poly(butylene terephthalate)/silica nanocomposites
Authors: Russo P. , Costantini A. , Luciani G. , Tescione F. , Lavorgna M. , Branda F. , Silvestri B.
Published: November 2017

In this work, experimental results about poly(butylene terephthalate) (PBT) based nanocomposites filled with various amounts of silica nanoparticles (NPs) are reported. Two different types of filler are used: silica gel NPs, produced through the Stöber method, and a commercial fumed silica, both coated by a PBT shell. Melt‐mixed samples have been thoroughly investigated by scanning and transmission electron microscopy, infrared Fourier transform spectroscopy (FTIR), thermal gravimetric analysis, differential scanning calorimetry, wide and small angle X‐ray diffraction, and dynamic mechanical analysis. A fine and very good dispersion of NPs into the polymeric matrix is revealed through the morphological analysis when Stöber NPs were used as filler with respect to systems including commercial fumed silica particles. This evidence, combined with matrix–filler interactions revealed by FTIR spectroscopy, justifies the enhancement of both storage modulus and glass transition temperature of the former samples in comparison with reference pristine PBT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46006.
Microporous membrane fabricated by AMS‐GMA‐TPE terpolymer grafted polypropylene prepared via extrusion
Authors: Jiang Shan , Wang Wei , Huang Tianya , Ma Jie , Ding Yonghong , Yu Qiang
Published: November 2017

Terpolymer poly(α‐methylstyrene‐co‐glycidyl methacrylate‐co‐4‐acryloyl tetraphenylethylene) (PAGT) was synthesized by radical copolymerization using α‐methylstyrene, glycidyl methacrylate, and trace fluorescent monomer 4‐acryloyl tetraphenylethylene. Thermal decomposition of α‐methylstyrene constitutional units in copolymer chains is known to produce macromolecular radicals at temperatures exceeding 90 °C, which may be melt‐grafted to polypropylene (PP) without other initiators by means of extrusion. In this study, the PP‐g‐PAGT microporous material was prepared by casting and stretching. The structure and properties of the PAGT were characterized by Fourier transform infrared spectroscopy, 1H‐nuclear magnetic resonance, and thermogravimetic analysis. The grafting degree and rheological properties proved that the PAGT chains were successfully grafted onto the PP. The uniformity of the PAGT in the PP‐g‐PAGT was observed using a spectrofluorophotometer. The polarity of the cast membrane was characterized by the water contact angle. The results showed that the PAGT evenly grafted onto the PP, and the polarity and hydrophilicity of the cast membranes were improved. The microporous structure of the separator was observed via scanning electron microscopy. Testing of the performance of the lithium battery showed that the impedance decreased and the ionic conductivity increased with the introduction of PAGT onto PP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46020.
Highly flame‐retardant bio‐based polyurethanes using novel reactive polyols
Authors: Bhoyate Sanket , Ionescu M. , Radojcic D. , Kahol P. K. , Chen J. , Mishra S. R. , Gupta Ram K.
Published: November 2017

Poor flame retardancy of polyurethanes (PU) is a global issue as it limits their applications particularly in construction, automobile, and household appliances industries. The global challenge of high flammability of PU can be addressed by incorporating flame‐retardant materials. However, additive flame‐retardants are non‐compatible and depreciate the properties of PU. Hence, reactive flame‐retardants (RFR) based on aliphatic (Ali‐1 and Ali‐2) and aromatic (Ar‐1 and Ar‐2) structured bromine compounds were synthesized and used to prepare bio‐based PU using limonene dimercaptan. The aromatic bromine containing foams showed higher close cell content (average 97 and 100%) and compressive strength (230 and 325 kPa) to that of aliphatic bromine containing foams. Similar behavior was observed for a horizontal burning test where with a low concentration of bromine (5 wt %) in the foams for Ar‐1 and Ar‐2 displayed a burning time of 12.5 and 11.8 s while, Ali‐1 and Ali‐2 displayed burning time of 25.7 and 37 s, respectively. Neat foam showed a burning time of 74 s. The percentage weight loss for neat PU foam was 26.5%, while foams containing 5 wt % bromine in Ali‐1, Ali‐2, Ar‐1, and Ar‐2 foams displayed weight loss of 11.3, 14, 7.9, and 14%, respectively. Our results suggest that flame retardant PU foams could be prepared effectively by using RFR materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46027.
Long‐term stable hydrophilic surface modification of poly(ether ether ketone) via the multilayered chemical grafting method
Authors: Kim Kyung Hak , Im Sang Hyuk , Park Bum Jun
Published: November 2017

The aging phenomena of a poly(ether ether keton) (PEEK) surface hydrophilically modified via various protocols was investigated. The use of plasma treatment or chemical etching methods offers a relatively convenient surface modification route. However, the effects of hydrophilic treatment quickly disappeared and its original surface property was recovered within a few hours or a few days when stored at ambient conditions. Surface treatment based on a single‐layered chemical grafting method rendered an excellent hydrophilic surface with an initial contact angle of <15° and an improved retardation of surface aging. However, the contact angle of the modified PEEK specimen gradually increased with time and eventually reached ∼50° after 23 days. A new method for the long‐term stable hydrophilic surface treatment of PEEK using a multilayered chemical grafting strategy was also developed. With this regard, aging of the modified surface could be significantly retarded over ∼90 days. It was believed that the effectiveness of the surface modification and the retarded aging phenomena via the multilayered hydrophilic treatment could be attributed to mechanical and chemical stability of the covalently bonded active surface groups on the grafted polymer networks. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46042.
Using State Birth Defects Registries to Evaluate Regional Critical Congenital Heart Disease Newborn Screening
Authors: Case Amy Peterson , Miller Stephanie D. , McClain Monica R.
Published: November 2017

Background

Most states have now passed legislation mandating pulse oximetry for all newborns, or have promulgated regulations or guidelines to encourage use of routine pulse oximetry. State‐based birth defects registries may be well positioned to track and evaluate critical congenital heart disease (CCHD) screening coverage and outcomes. This purpose of this study was to determine: (1) the proportion of cases detected by screening, (2) health services use by children with CCHDs during the first year of life, and (3) mortality outcomes.

Methods

Records of children born in 2012 to 2013 with any of seven CCHD lesions were identified in New England birth defects databases. Information was abstracted from each child's medical record. Descriptive statistics were used to report results.

Results

From nearly 160,000 live births, 208 CCHD diagnoses were noted in the records of 157 children. Screening was noted in 67% of records of confirmed cases of CCHDs. Data completeness varied by state; for example, information was available regarding prenatal diagnosis in 91% of records and age at first surgery in 85% among states with active surveillance compared with 35% and 75%, respectively, with passive surveillance. Documentation of screening results in medical records was inconsistent. The one year survival was 85% (77/91).

Conclusion

Birth defects surveillance systems can provide information on outcomes for infants with CCHDs. However, information varies by surveillance method and by hospital practices. Engaging hospitals in standardizing recording procedures and enhancing training and quality control could increase the value of birth defects registries records in assessing outcomes for children identified through CCHD screening. Birth Defects Research 109:1414–1422, 2017.© 2017 Wiley Periodicals, Inc.
Proximity to Pediatric Cardiac Surgical Care among Adolescents with Congenital Heart Defects in 11 New York Counties
Authors: Sommerhalter Kristin M. , Insaf Tabassum Z. , Akkaya‐Hocagil Tugba , McGarry Claire E. , Farr Sherry L. , Downing Karrie F. , Lui George K. , Zaidi Ali N. , Van Zutphen Alissa R.
Published: November 2017

Background

Many individuals with congenital heart defects (CHDs) discontinue cardiac care in adolescence, putting them at risk of adverse health outcomes. Because geographic barriers may contribute to cessation of care, we sought to characterize geographic access to comprehensive cardiac care among adolescents with CHDs.

Methods

Using a population‐based, 11‐county surveillance system of CHDs in New York, we characterized proximity to the nearest pediatric cardiac surgical care center among adolescents aged 11 to 19 years with CHDs. Residential addresses were extracted from surveillance records documenting 2008 to 2010 healthcare encounters. Addresses were geocoded using ArcGIS and the New York State Street and Address Maintenance Program, a statewide address point database. One‐way drive and public transit time from residence to nearest center were calculated using R packages gmapsdistance and rgeos with the Google Maps Distance Matrix application programming interface. A marginal model was constructed to identify predictors associated with one‐way travel time.

Results

We identified 2522 adolescents with 3058 corresponding residential addresses and 12 pediatric cardiac surgical care centers. The median drive time from residence to nearest center was 18.3 min, and drive time was 30 min or less for 2475 (80.9%) addresses. Predicted drive time was longest for rural western addresses in high poverty census tracts (68.7 min). Public transit was available for most residences in urban areas but for few in rural areas.

Conclusion

We identified areas with geographic barriers to surgical care. Future research is needed to determine how these barriers influence continuity of care among adolescents with CHDs. Birth Defects Research 109:1494–1503, 2017.© 2017 Wiley Periodicals, Inc.