bluuebunny/crossref_metadata_2025 huggingface dataset:
Flame retardant treated flax fibre reinforced phenolic composites: Ageing and thermal characteristics
Authors: Molaba Tshepiso Princess , Chapple Steve , John Maya Jacob
Published: July 2017

In this study, flax composites were prepared from flax fabric and phenolic resin. Chemical treatments were imparted to the fabric to improve adhesion between the fabric and the phenolic matrix. Diammonium phosphate was applied to improve the flammability of the composites. The thermal and flammability properties of the untreated, chemically treated, and flame retardant (FR) treated flax fabric reinforced phenolic composites were studied. Ageing studies were carried out by subjecting the composites to varying conditions of temperature and humidity in an environmental chamber for 2 weeks. FR treatment of flax fabric was shown to be very effective in improving flame retardancy of the composites due to decreased peak heat release rate (PHRR) and smoke production rate (SPR). Thermogravimetric analysis (TGA) of composites showed that after FR treatment, the decomposition temperatures shifted to lower temperatures. Ageing studies revealed that the mechanical properties of untreated, chemically treated and FR treated composites decreased with an increase in ageing temperature.
Synthesis and olfactory evaluation of (8S)‐(−)‐p‐Mentha‐1,3‐dien‐9‐ol and some of its esters
Authors: Radoias Georges , Bosilcov Alin , Ciocan‐Tarța Ilie , Bacher Markus
Published: July 2017

(8S)‐(−)‐p‐Mentha‐1,3‐dien‐9‐ol (3) has been synthesized and fully characterized, using dill ether as the starting material. Dill ether is a common constituent of the essential oil of dill weed, Anethum graveolens L. In the first step, (8S)‐(−)‐p‐mentha‐1,3‐dien‐9‐yl acetate was prepared by treating dill ether with anhydrous magnesium bromide, followed by the addition of acetic anhydride. Hydrolysis of this mixture with potassium hydroxide led to the formation of alcohol 3, with p‐cymen‐9‐ol as the main by‐product. The chemical identity of compound 3 has been confirmed by GC/MS, IR, one‐ and two‐dimensional NMR. Chiral analysis has shown that it consists of enantiomerically pure (8S)‐(−)‐p‐mentha‐1,3‐dien‐9‐ol. This has been corroborated by selective oxidation of p‐mentha‐1,3,8‐triene found in the essential oil of curly leaf parsley, Petroselinum crispum (Mill.) Fuss., to give a racemic mixture of p‐mentha‐1,3‐dien‐9‐ol. Other esters (propionate, butyrate and valerate) of alcohol 3 have been prepared in a similar way by treating dill ether with the corresponding acid anhydride. Olfactory evaluation of alcohol 3 revealed a floral character while its esters gave a range of fruity and herbaceous notes.
A Flower‐Shaped Thermal Energy Harvester Made by Metamaterials
Authors: Liu Wenmei , Lan Chuwen , Ji Muwei , Yao Jitan , Wang Jin , Li Bo , Zhou Ji
Published: July 2017

Harvesting thermal energy from arbitrary directions has become an exciting theoretical possibility. However, an exact 3D thermal energy harvester is still challenging to achieve for the stringent requirement of highly anisotropic and symmetrical structures with homogenous materials, as well as absence of effective characterization. In this Communication, a flower‐shaped thermal harvesting metamaterial is originally promoted. Numerical simulations imply that heat flux can be concentrated into the target core and a temperature gradient turns out to be more than two times larger than the applied one without obvious distortion or perturbation to the temperature profile outside the concentrator. Temperature transitions of the actual device are experimentally measured to validate the novel structure with consistency of the simulated results with original methods. With ultraefficiency independent of geometrical size, the flower‐shaped thermal harvester facilitates multiple scale energy harvesting with splendid efficient and might help to improve thermoelectric devices efficiency in a totally new perspective.
Age of crustal melting in Higher Himalayan Crystalline Sequence (Darjeeling, Eastern Himalaya): Constraints from SHRIMP U–Pb geochronology
Authors: Tewari S. , Prakash D.
Published: July 2017

The paper presents the petrological and geochronological studies of migmatite from an important section of Higher Himalayan Crystalline Sequence of Eastern Himalaya. Migmatites collected from the area characteristically contain biotite‐garnet‐sillimanite‐plagioclase‐K‐feldspar‐quartz as an important mineral assemblage, which has experienced extensive partial melting through dehydration melting reaction involving biotite. In this study, P–T evolution of these migmatites has been constrained through the use of multiequilibrium thermobarometry program winTWQ, conventional thermobarmetry, and pseudosection modelling in the MnNCKFMASHTO model system using Perple_X software. The unification of these three calculations demonstrates that the migmatite experienced peak pressure and temperature at 7.2 ± 0.5 kbar and 775 ± 20 °C, respectively. SHRIMP U–Pb chronological results yield the timing of crustal melting (21 Ma) in the migmatite.
Fractal characteristics of fault systems and their geological significance in the Hutouya poly‐metallic orefield of Qimantage, East Kunlun, China
Authors: He Hujun , An Le , Liu Wei , Yang Xingke , Gao Yaning , Yang Longwei
Published: July 2017

The fault fractal dimension is the integrated reflection of the quantity, scale, degree of development, combination mode, and dynamic mechanism of a fault and can be used as a quantitative indicator of fault structure complexity. In Hutouya polymetallic orefield of Qinghai province, China, the faults are developed, and many ore belts are located in the fault zone, which indicated that the faults have an important role in controlling mineralization. The two‐dimensional horizontal distribution of fault systems in the IV, V, VI, and VII ore zones of Hutouya orefield was studied based on fractal geometry. The fault distribution has fractal dimension values for zones IV, V, VI, and VII of 1.05, 1.157, 1.311, and 1.05, respectively. From the perspective of favourable structure, the potential for metallogenesis in the four ore zones is VI > VII > V > IV. The main controlling factor on ore formation in the Qimantage region is fault structure, and the results are consistent with the actual results. This work provides new insights into the relationship between fault systems and metallogenesis.
Metavolcanics from Capo Malfatano, SW Sardinia, Italy: New insight on the age and nature of Ordovician volcanism in the Variscan foreland zone
Authors: Cruciani Gabriele , Franceschelli Marcello , Puxeddu Mariano , Tiepolo Masssimo
Published: July 2017

The tectonic/stratigraphic interpretation of the Cambro–Ordovician rocks exposed in the south‐westernmost sectors of the Sardinia island (i.e., belonging to the Bithia Formation or Unit) is still a hot point of discussion. A debated question is also the age of the metavolcanics interbedded in these rocks. In order to provide a clear answer to this problem, in this paper, we provide new U–Pb zircon dating and a petrographic–geochemical comparison of metavolcanics interbedded within the Bithia Formation with similar Sardinian Ordovician calc‐alkaline rocks. The Bithia metavolcanics plot in the rhyodacite/rhyolite field. They show negative troughs for Nb and Ta, negative anomalies for Sr, P, and Ti, and positive peaks for Cs, Rb, K, Th, U, and Pb in the multielement diagram normalized to primitive mantle and significant LREE enrichment, marked negative Eu anomaly, and flat HREE patterns in the chondrite‐normalized REE diagram. Owing to these geochemical features, the Bithia metavolcanics plot in the volcanic arc and active continental margin fields closely resembling Middle‐Late Ordovician felsic metavolcanics from the Sarrabus, Gerrei, Goceano, and Mt. Grighini units. A new U–Pb zircon age of 462.1 ± 4.3 Ma yielded by a metavolcanic layer within the Bithia Formation at Capo Malfatano must be interpreted as the emplacement age. The CL and BSE images of zircon grains do not show any evidence of interaction with late hydrothermal fluids that could have caused Pb loss and rejuvenated ages, confirming the Middle‐Late Ordovician age of the metavolcanics.
Genomic Justice and Imagined Communities
Authors: Schwartz‐Marin Ernesto
Published: July 2017

In this issue of the Hastings Center Report, Maya Sabatello and Paul Appelbaum explore the assumptions about community embedded in the U.S. Precision Medicine Initiative, which aims to recruit donor‐partners who reflect the United States’ racial and ethnic diversity. As Sabatello and Appelbaum discuss, the initiative is like other national biobanking efforts in bringing to life an imagined genetic community in need of critical attention, and given the public‐private forms of partnership at the heart of the PMI, such efforts could become avenues to deepen existing inequalities rather than to alleviate them. The notion of justice has underwritten debates about genomic medicine, informed consent, citizenship, benefit sharing, and profit making since the first national biobanking project emerged at the dawn of the twenty‐first century. In a paradigmatic case, the creation, by an Icelandic company, of the deCODE genomic biobank opened up fierce debates about the proper relationship between public good and private gain and became the first global example of the economic and political implications that imagined genetic communities could have in our shared future. In Mexico, in 2001, the Icelandic case fueled a policy agenda to deal with global health justice and the prospects of a future market‐based colonialism predicated on the intimate knowledge of DNA.
Expanding the Horizon of Our Obligations in the Clinician‐Patient Relationship
Authors: Truog Robert D.
Published: July 2017

Johan Brännmark's article “Patients as Rights Holders,” in this issue of the Hastings Center Report, squarely identifies some important problems with the way we in clinical practice conceive of our obligations to our patients. As a solution, he helpfully suggests augmenting our focus on autonomy and informed consent with a broader menu of considerations drawn from the literature on human rights. Respect for autonomy is, of course, one of the hallowed principles of bioethics. In our traditional understanding, our patients deserve our respect because they are capable of autonomous choice, and the way we demonstrate our respect is by seeking their informed consent for our care. This model is so deeply ingrained that many of us have difficulty imagining that there could be any other way of thinking about it. But this model has two very serious drawbacks, problems that speak to much of what is wrong with health care today.
Shared Decision‐Making in Pediatrics: Honoring Multiple Voices
Authors: Benedetti Daniel J.
Published: July 2017

Historically, parents looking for guidance turned to a small cadre of trusted individuals such as grandparents and pediatricians. In the Internet era, this paradigm has shifted. With a few keystrokes, anxious parents have access to a seemingly endless array of opinions from faceless sources with unknown agendas. For some parents, this can cause more uncertainty, and for the parents of a child with a medical condition, navigating this information can be overwhelming.

In this modern paradigm, the pediatrician's duty has also become more complex, especially with the shift from paternalism to patient autonomy in medical decision‐making. It is within this context that Alan Fleischman's book, Pediatric Ethics: Protecting the Interests of Children, should be examined. A pediatrician and neonatologist, Fleischman has witnessed this evolution over more than five decades of practice. As a clinical and academic bioethicist, he has also witnessed a transformation in the field of bioethics, with shifting perspectives on areas such as research ethics and medical decision‐making. Because of his rich experience and deep understanding of the past and present of ethical issues in pediatrics, Fleischman approaches this subject with a perspective that warrants attention and thoughtful consideration.
miR‐130b directly targets ARHGAP1 to drive activation of a metastatic CDC42‐PAK1‐AP1 positive feedback loop in Ewing sarcoma
Authors: Satterfield Laura , Shuck Ryan , Kurenbekova Lyazat , Allen‐Rhoades Wendy , Edwards Dean , Huang Shixia , Rajapakshe Kimal , Coarfa Cristian , Donehower Lawrence A. , Yustein Jason T.
Published: July 2017

Ewing Sarcoma (ES) is a highly aggressive bone tumor with peak incidence in the adolescent population. It has a high propensity to metastasize, which is associated with dismal survival rates of approximately 25%. To further understand mechanisms of metastasis we investigated microRNA regulatory networks in ES. Our studies focused on miR‐130b due to our analysis that enhanced expression of this microRNA has clinical relevance in multiple sarcomas, including ES. Our studies provide insights into a novel positive feedback network involving the direct regulation of miR‐130b and activation of downstream signaling events contributing toward sarcoma metastasis. Specifically, we demonstrated miR‐130b induces proliferation, invasion, and migration in vitro and increased metastatic potential in vivo. Using microarray analysis of ES cells with differential miR‐130b expression we identified alterations in downstream signaling cascades including activation of the CDC42 pathway. We identified ARHGAP1, which is a negative regulator of CDC42, as a novel, direct target of miR‐130b. In turn, downstream activation of PAK1 activated the JNK and AP‐1 cascades and downstream transcriptional targets including IL‐8, MMP1 and CCND1. Furthermore, chromatin immunoprecipitation of endogenous AP‐1 in ES cells demonstrated direct binding to an upstream consensus binding site within the miR‐130b promoter. Finally, small molecule inhibition of PAK1 blocked miR‐130b activation of JNK and downstream AP‐1 target genes, including primary miR‐130b transcripts, and miR‐130b oncogenic properties, thus identifying PAK1 as a novel therapeutic target for ES. Taken together, our findings identify and characterize a novel, targetable miR‐130b regulatory network that promotes ES metastasis.
Timing of births and oral contraceptive use influences ovarian cancer risk
Authors: Wu Anna H. , Pearce Celeste Leigh , Lee Alice W. , Tseng Chiuchen , Jotwani Anjali , Patel Prusha , Pike Malcolm C.
Published: July 2017

Increasing parity and duration of combined oral contraceptive (COC) use provide substantial protection against ovarian carcinoma (cancer). There are limited data on the impact of the age of the births or age of COC use on reducing ovarian cancer risk. Here, we examined the effects of age at first and last births and age at use of COCs using data from studies conducted in Los Angeles County, California, USA (1,632 cases, 2,340 controls). After adjusting for the number of births, every 5 years that a first birth was delayed reduced the risk of ovarian cancer by 13% (95% CI 5–21%; p = 0.003); a first birth after age 35 was associated with a 47% lower risk than a first birth before age 25. COC use before age 35 was associated with greater protection per year of use than COC use at older ages. Considering previously published results as well as the results presented here, increasing parity and a later age at births are both important protective factors against ovarian cancer and the protection extends over 30 or more years from last birth. Current models of the etiology of ovarian cancer do not encompass an effect of late age at births. Our result of an attenuation of the protective effect with COC use after around age 35 needs further investigation as it has not been seen in all studies.
Contracted Schrödinger equation in quantum phase‐space
Authors: Frishberg Carol , Cohen Leon
Published: July 2017

The phase space formulation of quantum mechanics is equivalent to standard quantum mechanics where averages are calculated by way of phase space integration as in the case of classical statistical mechanics. We derive the quantum hierarchy equations, often called the contracted Schrödinger equation, in the phase space representation of quantum mechanics which involves quasi‐distributions of position and momentum. We use the Wigner distribution for the phase space function and the Moyal phase space eigenvalue formulation to derive the hierarchy. We show that the hierarchy equations in the position, momentum, and position‐momentum representations are very similar in structure. © 2017 Wiley Periodicals, Inc.
A Structural Model of Nitro‐Porphyrin Dyes Based on Spectroscopy and Density Functional Theory
Authors: Farley Christopher , Aggarwal Amit , Singh Sunaina , Dolor Aaron , To Philip , Falber Alexander , Crossley Maxwell , Drain Charles Michael
Published: July 2017

Nitro‐porphyrins are an important class of commercial dyes with a range of potential applications. The nitro group is known to dramatically affect the photophysics of the porphyrin, but there are few systematic investigations of the contributing factors. To address this deficiency, we present spectroscopic studies of a series of nitro‐porphyrins, accompanied by density functional theory calculations to elucidate their structures. In particular, we explore how the positions of the substituents affect the energy levels and nuclear geometry. As expected, nitro groups on the meso‐phenyl rings cause small changes to the orbital energies by induction, while those at the β‐pyrrole positions more strongly conjugate into the aromatic system. In addition, however, we find evidence that β‐pyrrole nitro groups distort the porphyrin, creating two non‐planar conformations with distinct properties. This unexpected result helps explain the anomalous photophysics of nitro‐porphyrins reported throughout the literature, including inhomogeneous line broadening and biexponential fluorescence decay. © 2017 Wiley Periodicals, Inc.
Ab Initio energetics of SiO bond cleavage
Authors: Hühn Carolin , Erlebach Andreas , Mey Dorothea , Wondraczek Lothar , Sierka Marek
Published: July 2017

A multilevel approach that combines high‐level ab initio quantum chemical methods applied to a molecular model of a single, strain‐free SiOSi bridge has been used to derive accurate energetics for SiO bond cleavage. The calculated SiO bond dissociation energy and the activation energy for water‐assisted SiO bond cleavage of 624 and 163 kJ mol−1, respectively, are in excellent agreement with values derived recently from experimental data. In addition, the activation energy for H2O‐assisted SiO bond cleavage is found virtually independent of the amount of water molecules in the vicinity of the reaction site. The estimated reaction energy for this process including zero‐point vibrational contribution is in the range of −5 to 19 kJ mol−1. © 2017 Wiley Periodicals, Inc.
Comparing pairwise‐additive and many‐body generalized Born models for acid/base calculations and protein design
Authors: Villa Francesco , Mignon David , Polydorides Savvas , Simonson Thomas
Published: July 2017

Generalized Born (GB) solvent models are common in acid/base calculations and protein design. With GB, the interaction between a pair of solute atoms depends on the shape of the protein/solvent boundary and, therefore, the positions of all solute atoms, so that GB is a many‐body potential. For compute‐intensive applications, the model is often simplified further, by introducing a mean, native‐like protein/solvent boundary, which removes the many‐body property. We investigate a method for both acid/base calculations and protein design that uses Monte Carlo simulations in which side chains can explore rotamers, bind/release protons, or mutate. The fluctuating protein/solvent dielectric boundary is treated in a way that is numerically exact (within the GB framework), in contrast to a mean boundary. Its originality is that it captures the many‐body character while retaining the residue‐pairwise complexity given by a fixed boundary. The method is implemented in the Proteus protein design software. It yields a slight but systematic improvement for acid/base constants in nine proteins and a significant improvement for the computational design of three PDZ domains. It eliminates a source of model uncertainty, which will facilitate the analysis of other model limitations. © 2017 Wiley Periodicals, Inc.
Electric fields accelerate cell polarization and bypass myosin action in motility initiation
Authors: Sun Yao‐Hui , Sun Yuxin , Zhu Kan , Reid Brian , Gao Xing , Draper Bruce W. , Zhao Min , Mogilner Alex
Published: July 2017

Stationary symmetrical fish keratocyte cells break symmetry and become motile spontaneously but slowly. We found that applying electric field (EF) accelerates the polarization by an order of magnitude. While spontaneously polarized cells move persistently for hours, the EF‐induced polarity is lost in a majority of cells when the EF is switched off. However, if the EF is applied for a long time and then switched off, the majority of cell move stably. Myosin inhibition abolishes spontaneous polarization, but does not slow down EF‐induced polarization, and after the EF is turned off, motility does not stop; however, the cell movements are erratic. Our results suggest that the EF rapidly polarizes the cells, but that resulting polarization becomes stable slowly, and that the EF bypasses the requirement for myosin action in motility initiation.
Pharmacokinetics and Safety of Brexpiprazole Following Multiple‐Dose Administration to Japanese Patients With Schizophrenia
Authors: Ishigooka Jun , Iwashita Shuichi , Higashi Koushi , Liew Ei Leen , Tadori Yoshihiro
Published: July 2017

Brexpiprazole is currently approved in the United States for the treatment of schizophrenia and as adjunctive treatment of major depressive disorder. In Canada, it is approved for the treatment of schizophrenia. This study evaluated the pharmacokinetics (PK) and safety of brexpiprazole in Japanese patients with schizophrenia. This phase 1 study comprised a 14‐day multiple‐dose administration of brexpiprazole 1, 4, and 6 mg/day (n = 7, 8, and 6, respectively). Plasma concentrations and PK parameters and the influence of CYP2D6 polymorphisms (intermediate metabolizers [IMs] and extensive metabolizers [EMs]) on PK were evaluated. Adverse events (AEs) were recorded. The Cmax and AUC24h of brexpiprazole and its metabolite, DM‐3411, showed dose‐proportionality. The Cmax and AUC24h of brexpiprazole showed accumulation of about 2.5‐ to 5.5‐fold on day 14, compared with those on day 1. The median tmax and the mean elimination half‐life of brexpiprazole were 4–5 and 52–92 hours, respectively, across all doses on day 14. The C24h of brexpiprazole reached steady state after day 10 in all dose groups. The dose‐normalized Cmax and AUC24h of brexpiprazole on day 14 were higher in IM patients than in EM patients. AEs were generally mild to moderate, with transient serum prolactin increase being the most common event. No clinically significant changes were observed for other clinical laboratory values. Brexpiprazole was safe and well tolerated in the studied Japanese patients with schizophrenia.
Polymorphism of IL10, IL4, CTLA4, and DAO Genes in Cross‐Reactive Nonsteroidal Anti‐inflammatory Drug Hypersensitivity
Authors: Ferreira Vasconcelos Luciana Mabel , Rodrigues Raphael de Oliveira , Albuquerque Andressa Almeida , Barroso Gabrielle Dantheias , Sasahara Greyce Luri , Severo Ferreira Janaira Fernandes , Francelino Eudiana Vale , Cardoso Cynthia Chester , Barem Rabenhorst Silvia Helena , de Almeida Thereza Lúcia Prata , Nagao‐Dias Aparecida Tiemi
Published: July 2017

Our aim was to evaluate genetic polymorphism of molecules involved in immunoregulatory/allergic processes in patients who presented with cutaneous hypersensitivity caused by chemically unrelated nonsteroidal anti‐inflammatory drugs. Polymorphisms at IL10 (–1082 G>A), IL4 (–589 C>T), CTLA4 (+49A>G), and DAO (+8956 C>G) genes were studied in 55 cases and 97 controls by the polymerase chain reaction‐restriction fragment length polymorphism technique. With regard to the polymorphism at IL10 –1082, higher frequencies of the AG genotype (57% vs 39%) and G allele carriers (70% vs 48%) were found among the patients, indicating a risk effect (odds ratio [OR] = 2.56 and P = .01 for AG genotype and OR = 2.52; P = .01 for AG/GG). For the CTLA4 +49 A/G single‐nucleotide polymorphism (SNP), AG genotype (31.0%) (P = .02) and G carrier (54.0%) (P = .05) frequencies were found to be significantly lower in the patient group compared with the control group (51.0% and 69.0%, respectively). The SNP DAO +8956 C>G was associated with a strong protective effect, with OR values of 0.83 for CG and 0.11 for GG genotype (P = .04 for the codominant model), suggesting an allele dose effect. The combination of IL10 and DAO SNPs in a multivariate model did not alter the OR values, suggesting independent effects for both SNPs. The results are striking. In conclusion, these results suggest that polymorphisms in regulatory targets of the immune response and in DAO gene could modulate an individual's susceptibility to nonsteroidal anti‐inflammatory drug hypersensitivity reactions. Further studies will be necessary to complement our results.
Changes in margin re‐excision rates: Experience incorporating the “no ink on tumor” guideline into practice
Authors: Patten Caitlin R. , Walsh Kendall , Sarantou Terry , Hadzikadic‐Gusic Lejla , Forster Meghan R. , Robinson Myra , White Richard L.
Published: July 2017

Introduction

Prior to the “no ink on tumor” SSO/ASTRO consensus guideline, approximately 20% of women with stage I/II breast cancers undergoing breast conservation surgery at our institution underwent margin re‐excision. On May 20, 2013, our institution changed the definition of negative margins from 2 mm to “no ink on tumor.”

Methods

A retrospective review was conducted of patients who had surgery at our institution with clinical stage I/II breast cancers between June 1, 2011 and May 1, 2015. In the pre‐guideline cohort (pre) and post‐guideline cohort (post), negative margins were 2 mm and “no ink on tumor,” respectively.

Results

Implementation of the guideline resulted in a significant decrease in the positive/close margin rate (29.6% pre vs 10.1% post; P < 0.001) and numerical decrease in re‐excision rate (20.4% pre vs 16.3% post; P = 0.104). No significant difference was found in local recurrence between the cohorts with limited follow‐up (1.2% pre vs 1.5% post; P = 0.787).

Conclusion

The implementation of the “no ink on tumor” guideline at our institution has resulted in a significant decrease in positive margin rates and a numerical decrease in margin re‐excisions. In addition to margin status, surgeons continue to use individual patient and histologic factors to decide for or against margin re‐excision.
Effect of fabrication strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized polymethacrylate monoliths: A comparative evaluation
Authors: Lin Yuanjing , Guo Jialiang , Lin Hang , Wang Jincai , Somsen Govert W. , Crommen Jacques , Jiang Zhengjin
Published: July 2017

To evaluate the effect of the preparation strategy on the enantioseparation performance of β‐cyclodextrin‐functionalized monoliths, a series of β‐cyclodextrin‐functionalized organic polymeric monolithic columns were prepared through two‐step, single‐step, and one‐pot approaches, using the same cyclodextrin, linker–spacer, and crosslinker. Physicochemical characterization of the columns was carried out by determining the morphology, β‐cyclodextrin density, permeability, and chromatographic efficiency. For each type of monolithic column, the enantioresolution of 22 chiral compounds, including mandelic acid derivatives, nonsteroidal anti‐inflammatory drugs, N‐derivatized amino acids, and herbicides, was comparatively studied under optimum chromatographic conditions. The β‐cyclodextrin‐functionalized monolithic columns prepared through the one‐pot approach exhibited higher enantioresolution for most chiral compounds, and they have the advantage of good controllability and simple preparation. On the other hand, the enantioresolution obtained on columns prepared through the single‐step approach was quite unsatisfactory, and therefore the effect of using different linking spacers and crosslinkers was studied. A significant improvement of enantioresolution for 2‐chloro‐mandelic acid was obtained by using N,N‐methylenebisacrylamide instead of ethylene dimethacrylate as the crosslinker in the single‐step preparation.
Who is ethnic neighborhood tourism for anyway? Considering perspectives of the dominant cultural group
Authors: Maruyama Naho U. , Woosnam Kyle M. , Boley Bynum B.
Published: July 2017

Past studies regarding “ethnic neighborhood tourism” (ENT) have primarily reflected perspectives of the ethnic minority group whose culture is represented to tourists. Therefore, this study explored how members of the ethnic “majority” group who live in the ethnic neighborhood perceive ENT in their own community. The interpretive analysis of 31 interviews with Japanese residents in a Brazilian neighborhood in Oizumi, Gunma, Japan, revealed that the Japanese residents are reluctant and somewhat antagonistic towards ENT in their community. This study also illustrates that ENT reinforced the ethnic divide within the town rather than healing past tensions between the 2 groups.
Ultrasound Curricula in Undergraduate Medical Education: A Scoping Review
Authors: Tarique Usman , Tang Brandon , Singh Manni , Kulasegaram Kulamakan Mahan , Ailon Jonathan
Published: July 2017

The clinical applications of point‐of‐care ultrasound (US) have expanded rapidly over the past decade. To promote early exposure to point‐of‐care US, there is widespread support for the integration of US curricula within undergraduate medical education. However, despite growing evidence and enthusiasm for point‐of‐care US education in undergraduate medical education, the curricular design and delivery across undergraduate medical education programs remain variable without widely adopted national standards and guidelines. This article highlights the educational and teaching applications of point‐of‐care US with a focus on outcomes. We then review the evidence on curricular design, delivery, and integration and the assessment of competency for point‐of‐care US in undergraduate medical education.
Highly cis‐1,4 Selective Living Polymerization of Unmasked Polar 2‐(2‐Methylidenebut‐3‐enyl)Furan and Diels–Alder Addition
Authors: Long Shiyu , Lin Fei , Yao Changguang , Cui Dongmei
Published: July 2017

The polymerization of a new polar diene‐based monomer 2‐(2‐methylidenebut‐3‐enyl)furan (MBEF) without masking is achieved by using the bis(phosphino)carbazoleide‐ligated yttrium (Y) alkyl complex upon the activation of [Ph3C][B(C6F5)4]. Under mild conditions, the polymerizations under the monomer‐to‐Y ratios ranging from 100:1 to 500:1 perform fluently in high yields. The afforded polydienes bearing pendant terminal furan groups have high cis‐1,4‐regularity up to 98.6% and molecular weights close to the theoretic values and narrow polymer dispersity index(PDI) (1.13–1.17) suggesting a livingness polymerization mode. In addition, this novel polydiene is an excellent building block for preparing functional rubber materials. For example, via Diels–Alder addition of furan groups under mild conditions, hydroxyl groups are successfully introduced on the side chains efficiently in a 75% conversion. Furthermore, the copolymerization of polar MBEF and nonpolar isoprene is also successfully realized by the bis(phosphino) carbazoleide‐ligated scandium analog to access furan‐modified cis‐1,4 (>97%) polyisoprene with different MBEF contents (5.3%, 8.7%).
The Origin of Hierarchical Structure Formation in Highly Grafted Symmetric Supramolecular Double‐Comb Diblock Copolymers
Authors: Hofman Anton H. , Reza Mehedi , Ruokolainen Janne , ten Brinke Gerrit , Loos Katja
Published: July 2017

Involving supramolecular chemistry in self‐assembling block copolymer systems enables design of complex macromolecular architectures that, in turn, could lead to complex phase behavior. It is an elegant route, as complicated and sensitive synthesis techniques can be avoided. Highly grafted double‐comb diblock copolymers based on symmetric double hydrogen bond accepting poly(4‐vinylpyridine)‐block‐poly(N‐acryloylpiperidine) diblock copolymers and donating 3‐nonadecylphenol amphiphiles are realized and studied systematically by changing the molecular weight of the copolymer. Double perpendicular lamellae‐in‐lamellae are formed in all complexes, independent of the copolymer molecular weight. Temperature‐resolved measurements demonstrate that the supramolecular nature and ability to crystallize are responsible for the formation of such multiblock‐like structures. Because of these driving forces and severe plasticization of the complexes in the liquid crystalline state, this supramolecular approach can be useful for steering self‐assembly of both low‐ and high‐molecular‐weight block copolymer systems.
Frictional versus Kelvin‐Voigt damping in a transmission problem
Authors: Portillo Oquendo Higidio
Published: July 2017

We consider 2 transmission problems. The first problem has 2 damping mechanisms acting in the same part of the body, one of frictional type and other of Kelvin‐Voigt type. In this case, we show that, even though it has too much dissipation, the semigroup is not exponentially stable. The second problem also has those damping terms but they act in complementary parts of the body. For this case, we show that the semigroup is exponentially stable and it is not analytic.
Rotating periodic solutions for asymptotically linear second‐order Hamiltonian systems with resonance at infinity
Authors: Liu Guanggang , Li Yong , Yang Xue
Published: July 2017

In this paper, we consider a class of asymptotically linear second‐order Hamiltonian system with resonance at infinity. We will use Morse theory combined with the technique of penalized functionals to obtain the existence of rotating periodic solutions.
A multi‐functional tri‐mode patch antenna supporting dual‐band GPS and wireless communication system
Authors: Cai Y.‐M. , Li K. , Yin Y. , Zhao L.
Published: July 2017

This letter presents a trimode multi‐functional patch antenna for GPS and wireless communication applications. The antenna consists of a folded annular slot, a section of coaxial cable, shorting copper columns and the ground plane. Tri‐band operation is realized by exciting three different working modes including microstrip antenna mode, slot antenna mode and monopole antenna mode. The proposed antenna is designed to cover the GPS L1 and L2 bands, UMTS‐band 5. At the GPS bands, the antenna is unidirectional with right‐hand circular polarization. At the telecommunication band, an omnidirectional radiation pattern is realized with linear polarization. The design is fabricated by standard PCB technologies, and its performance is validated by measurement.
Dual‐band circularly polarized hybrid antenna for WLAN/WiMAX applications
Authors: Sharma Anand , Das Gourab , Gangwar Ravi Kumar
Published: July 2017

In this article, a dual‐band circularly polarized hybrid antenna is examined and discussed. In this composition, the diagonally trimmed square shaped slot (modified slot) acts as a radiator and the feeding network of CDRA. Modified slot has been adopted to excite the orthogonal modes (
and
) in CDRA, which is responsible for the origination of circularly polarized (CP) waves in lower frequency band (2.68–3.04 GHz). Furthermore, a combination of V‐shaped microstrip line with modified slot is utilized to generate CP waves in upper frequency band (5.12–5.34 GHz). The sense of polarization can be altered by taking mirror image of the modified slot. To verify the simulated outcomes, the archetype of proposed design is fabricated and tested. Experimental results show good settlement with simulated results. The proposed radiator operates over two frequency bands, i.e. 2.36–3.22 GHz and 5.0–5.34 GHz with the fractional bandwidth of 30.82 and 6.57%, respectively. Measured 3‐dB axial ratio bandwidth is ∼12.20 and 4.2% in lower and upper frequency band, respectively. The proposed antenna structure is quite appropriate for WLAN (2.4/5.2 GHz) and WiMAX (2.5 GHz) applications.
Single‐polarized wideband array antenna of all‐metal structure with modified TSA elements
Authors: Kim In‐Seon , Lee Chang‐Hoon , Choi Sam‐Yeul , Kim Joon‐Yong
Published: July 2017

This article presents a wideband wide‐angle tapered slot array (TSA) antenna with no grating lobes in the 6–18 GHz band and the required scan range (azimuth angle ≤ |42.5°|, elevation angle ≤ |22.5°|). The unit element in the array antenna is a modified type of the existing TSA elements. We studied the various parameters for the proposed structure to investigate their effect. A single antenna and an 8 × 8 array antenna with the proposed structure were designed and fabricated. The validity of the proposed structure and design procedure has been verified by the agreement between the simulated and measured results.
Ultrawideband doubly tapered slot antenna (DTSA) with integrated balun as a feed for time‐domain target detection
Authors: Pegwal Saurabh , Abegaonkar Mahesh P. , Koul Shiban K.
Published: July 2017

This article discusses the design of an ultrawideband doubly tapered slot antenna (DTSA) using an ultrawideband balun at its input feeding network. The proposed antenna with integrated balun is completely planar in nature with a conventional microstrip feed. The complete antenna structure with integrated balun realized on an 8 mil Rogers's RO4003C substrate shows a measured return loss of better than 10 dB from 4 to 36 GHz and measured peak gain of 2.08–8.44 dB for the entire band. The time domain characteristics of the transmitting/receiving system using the proposed ultrawideband (DTSA) antenna is also investigated giving a low variation in group delay (≤0.18 nsec). This transmitting/receiving system with the proposed antenna is further used to demonstrate possibility of using this antenna for target detection.
Dual‐mode dual‐band microstrip bandstop filter design with independently tunable center frequencies
Authors: Gorur Ali Kursad , Basmaci Filiz Ayse Nihan , Dogan Engin , Karpuz Ceyhun , Gorur Adnan
Published: July 2017

In this article, a novel dual‐mode dual‐band bandstop filter design with independently tunable center frequencies is presented by using dual‐mode square loop resonators. Tuning operation can be achieved with a constant fractional bandwidth. Varactor diodes are used instead of perturbation and reference elements. Two dual‐mode square loop resonators in different electrical lengths are coupled to a transmission line connecting input and output ports. Center frequencies of both stopbands can be independently tuned by changing the capacitances of varactor diodes of both perturbation and reference elements. While the perturbation and reference varactors tune even mode resonance frequency together, odd mode resonance frequency can only be tuned by reference varactors. The designed filter was also fabricated for the experimental studies and it exhibits acceptable tunability operations in measurements. Center frequencies of the first and second stopbands can be tuned between 2.2 and 2.54 GHz and between 3 and 3.38 GHz, respectively. Rejection levels for both stopbands were obtained as better than −13 dB in the whole tuning range.
A new double T‐U‐shaped biaxial compact double‐negative meta‐atom for multiband applications
Authors: Hossain Mohammad Jakir , Faruque Mohammad R. I. , Islam Mohammad T.
Published: July 2017

In this research, a new biaxial double‐negative (DNG) meta‐atom for multiband operation has been designed, fabricated, and measured that can work in the microwave region. The proposed meta‐atom structure offers DNG properties for three axes (x, y, and z) electromagnetic (EM) wave propagation through the meta‐atom structure. For along the x‐axis EM wave propagation, meta‐atom exhibits DNG characteristics in the L‐band. Similarly, for along the y‐axis EM wave propagation, it displays DNG characteristics in the C‐band. The meta‐atom shows DNG properties in Ku‐band for along the z‐axis propagation. Commercially available Computer Simulation Technology electromagnetic simulator was adopted to examine the design of the meta‐atom. The measured results showed good agreement with the simulated one. The meta‐atom has exhibited multiband response in conjunction with the DNG property over the certain frequency bands in the microwave spectra.
A bandwidth enhanced metasurface antenna for wireless applications
Authors: Rajak Neha , Chattoraj Neela
Published: July 2017

This article presents a two layer metasurface antenna in which the top layer is metasurface and the bottom layer is patch antenna. The metasurface enhances the bandwidth and gain of the patch antenna. The metasurface is composed of an array of radiating element which is arranged in 5 × 6 layout. Complementary split ring resonator is used as radiating element. The substrate used for metasurface and patch antenna is Rogers RO4350B having loss tangent of 0.0037, relative permittivity of 3.48 and thickness of 1.524 mm.The overall length and width of the total structure is 0.72λo × 0.95λo (38 × 50 mm2). The metasurface is acting as Double Negative material in which permeability and permittivity both are negative so as a result refractive index will also be negative. The waves coming out of the patch antenna is affected by the array of radiating element on the metasurface, which is above the patch antenna due to which equivalent relative permittivity and permeability of the structure changes and therefore there is change in the performance of the patch antenna. The proposed antenna resonates at 5.7 GHz with bandwidth enhancement from 150 to 260 MHz with gain of 5.8 dBi. The return loss bandwidth is found to be 2.83% (5.64–5.8 GHz) under simulation and 4.64% (5.62–5.78 GHz) under measurement at the resonating frequency when metasurface is used with patch antenna. Overall 39% increase in return loss bandwidth is achieved. The fractional bandwidth of 55.22% is achieved. The proposed antenna is useful for WiFi application.
Compact microstrip patch antenna proclaiming super wideband characteristics
Authors: Rahman M. N. , Islam M. T. , Mahmud M. Z. , Samsuzzaman M.
Published: July 2017

In this study, a compact crescent‐shaped microstrip patch antenna is proposed for super wideband (SWB) applications. The antenna consists of a rectangular, slotted partial ground plane and a crescent shape radiating patch to cover wider frequency band than the ultrawideband. The proposed antenna is fabricated on an FR4 substrate and is fed with a 50 Ω microstrip feed line. The substrate has a thickness of 1.60 mm with the relative permittivity of 4.4, and a dielectric loss tangent of 0.02. The proposed antenna has a compact size of 32 mm × 22 mm with the electrical dimension of 0.27λ × 0.18λ. The simulated results agree with the measured results. The result shows that the proposed antenna achieves reflection coefficient less than −10 dB (VSWR < 2) from 2.5 GHz to 29.0 GHz that is a 168.25% fractional bandwidth with 11.6:1 bandwidth ratio. The proposed antenna achieves the durable omnidirectional radiation pattern throughout the operating band with 6.10 dBi of maximum gain. The bandwidth dimension ratio of the presented antenna is 3462.02. As the antenna shows the SWB characteristics, it can be used in the high fidelity short pulse applications. The proposed antenna can be used in S, C, X, Ku, K, ISM, Wi‐Fi, WLAN, WiMAX, and MVDDS wireless communication systems.
A flexible UWB inverted‐F antenna for wearable application
Authors: Xu Li‐Jie , Wang Hui , Chang Yumei , Bo Yaming
Published: July 2017

A novel flexible antenna is proposed for communication with implanted devices in this letter. Polyimide is adopted as flexible substrate for conformal property. Based on inverted‐F structure, bow‐tie shaped structure is introduced on the top layer to achieve wideband performance. Besides, top and bottom layers are connected with a metal wall, which not only helps with miniaturization, but also leads to single‐sided fabrication requirement. Furthermore, the communication link with implanted antenna is estimated. Finally, the proposed flexible antenna is measured both in the air and around wrist in conformal form, showing good agreement with simulation results.
Design of high return loss logarithmic spiral antenna
Authors: Morbidel Leonardo , Bulus Rossini Laureano A. , Costanzo Caso Pablo A.
Published: July 2017

We propose a new strategy for designing a logarithmic spiral antenna and the impedance adapter to operate in a frequency range of 1 to 10 GHz. Numerical and experimental results show a decrease in return loss being higher than 20 dB in almost the entire range of operation.
Mechanically pattern reconfigurable dual‐band antenna with omnidirectional/directional pattern for 2.4/5GHz WLAN application
Authors: Li Peng Kai , You Chang Jiang , Yu Hong Fang , Cheng Yu Jian
Published: July 2017

A mechanically pattern reconfigurable dual‐band antenna with an omnidirectional radiation pattern or a directional pattern for 2.4/5GHz dual‐band WLAN application is presented. By manually rotating the top substrate, the antenna can operate at patch state or monopole state, respectively. A novel U‐gap structure consisting of an outer patch, an inner patch and a U‐shaped gap is introduced to achieve the dual band feature at both operation states. The measured overlapped bands of the two states are 2.4–2.56 GHz and 5.22–6 GHz, covering the 2.4–2.48 GHz and most of the 5.15–5.85 GHz WLAN band. The measured peak gain is 2.4 dBi at 2.5GHz, 6.2 dBi at 5.5 GHz for monopole state, and 5.8 dBi at 2.5 GHz, 7.2 dBi at 5.5 GHz for patch state.
A fully integrated W‐band pulse compression radar CMOS transceiver
Authors: Oh Juntaek , Jang Jingyu , Hong Songcheol
Published: July 2017

A fully integrated ultra‐wideband (UWB) W‐band pulse compression radar transceiver in a 65‐nm CMOS technology is presented. The transceiver adopts a pulse compression scheme for high power spectral density with low TX leakage. Two identical voltage controlled oscillators, which are coupled through the second harmonic, are designed to achieve high output power and low phase noise without buffers. A transformer‐based local oscillator distribution network is proposed to achieve both small chip area and high port‐to‐port isolation. The transceiver chip produces 7.5‐GHz UWB RF pulses with 14.5‐dBm peak output power in the tuning range of 75–81 GHz, while the receiver shows a dynamic range of above 60 dB. The radar module was realized with waveguide transitions from a micro‐strip to a WR‐10 waveguide, and was capable of differentiating two targets with 6.5‐cm separation within 30 m distance.
Finger‐worn end‐fire antenna for MM‐wave applications
Authors: Mantash M. , Denidni T. A.
Published: July 2017

A novel antenna candidate for intelligent wearable systems at 30 GHz is presented in this letter. It consists of a compact axial‐mode helical antenna with a ground plane mounted on a plastic ring. This choice allows to achieve a wide bandwidth and circular polarization in a compact package. A prototype is manufactured, and the different classical key antenna metrics are investigated: return loss, realized gain, axial ratio and radiation pattern. The bandwidth and radiation characteristics obtained make the wearable ring antenna suitable to be used for MM‐wave applications within the frequency band from 25 to 33 GHz.