bluuebunny/crossref_metadata_2025 huggingface dataset:
Fe2Si5N8: Access to Open‐Shell Transition‐Metal Nitridosilicates
Authors: Bielec Philipp , Janka Oliver , Block Theresa , Pöttgen Rainer , Schnick Wolfgang
Published: February 2018

Highly condensed nitridosilicates doped with Eu2+ or Ce3+ play an important role in saving energy by converting the blue light of (In,Ga)N‐LEDs. Although nitridosilicates are known for great structural variety based on covalent anionic Si‐N networks, elemental variety is restricted. Presenting a significant extension of the latter, this work describes a general access to open‐shell transition‐metal nitridosilicates. As a proof‐of‐principle, the first iron nitridosilicate, namely Fe2Si5N8, was prepared by exchanging Ca2+ in α‐Ca2Si5N8 applying a FeCl2 melt (salt metathesis). The title compound was analyzed by powder X‐ray diffraction, EDX, ICP‐OES, combustion analysis, TG/DSC, Mössbauer spectroscopy and magnetic susceptibility measurements. Furthermore, the structure of α‐Ca2Si5N8 was determined at 1073 and 1173 K confirming the anionic network of α‐Ca2Si5N8 providing possible migration pathways for the ion‐exchange reaction.
Recyclable bio‐based crosslinked polyurethanes with self‐healing ability
Authors: Gu Lin , Wu Qing‐Yun
Published: February 2018

We report the synthesis of a linear bio‐based polyurethane (bio‐PU) containing furan ring by using renewable polylactide copolymer diol and 2,5‐furandimethanol as a soft segment and chain extender, respectively, in which the reversible crosslinked covalent bonds between hard segments were incorporated via Diels–Alder (D‐A) reaction between the furan ring of the chain extender and bismaleimide (BM) crosslinker. By simply controlling the amount of BM, mechanical properties of the obtained crosslinked bio‐PUs (CBPUs) were varied widely. In particular, the CBPU100 sample shows the highest tensile strength of 10.8 MPa, Young's modulus of 193 MPa, and an elongation of 155%. The differential scanning calorimetry experiments verify the recycle property of the CBPUs by the D‐A/retro‐D‐A reaction at the proper temperature. The thermal recyclability and remolding ability of these materials are demonstrated by two kinds of polymer processing methods, i.e., solution casting and hot‐compression molding. The recycled CBPUs display almost identical elongation and slightly decreased tensile strength compared to the as‐synthesized samples. Furthermore, the CBPUs also exhibit excellent self‐healing ability. Therefore, the resulting CBPUs possess tunable mechanical properties, good thermal recyclability, re‐mending, and self‐healing ability, which makes the bio‐based materials more eco‐friendly. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46272.
Low corrosion optically clear adhesives for conducting glass: I. Effects of N,N‐diethylacrylamide and acrylic acid mixtures on optically clear adhesives
Authors: Kuo Chung‐Feng Jeffrey , Chen Jiong‐Bo , Chang Shu‐Hao
Published: February 2018

This study designs less corrosive optically clear adhesives (OCAs) with good rework properties, where copolymer and glycidyl methacrylate (GMA) are cured by ultraviolet to form OCAs. The copolymer are synthesized by using N,N‐diethylacrylamide (DMA), acrylic acid (AA), and 2‐ethylhexyl acrylate. The DMA and AA could form acid–base interaction and therefore lower the corrosion on metallic substrate caused by AA. Copolymer is applied in OCAs, as different adhesive properties are presented. In terms of the adhesive property of OCAs, the peel strength, shear strength, and transmittance property are decreased when the GMA concentration is increased. The tack and haze are enhanced accordingly. After 7 days' standing at 60 °C and 90% RH, OCAs have no obvious corrosion on the conductive glass circuits, and there is no residue after peeling off. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46277.
Impact of specialist management on survival from radiation-associated angiosarcoma of the breast
Authors: Feinberg L. , Srinivasan A. , Singh J. K. , Parry M. , Stevenson J. , Jeys L. , Grimer R. , Peart F. , Warner R. , Ford S. , Gourevitch D. , Hallissey M. , Desai A.
Published: February 2018

Background

Radiation-associated angiosarcoma of the breast (RAAS) is a rare complication of adjuvant radiotherapy associated with poor survival. The British Sarcoma Group guidelines recommend that all angiosarcomas are referred to a sarcoma multidisciplinary team, although there is no recommendation that patients are managed within a sarcoma service. The aims of this study were to compare survival, complete excision rates and local recurrence rates of patients managed within a sarcoma service and those managed within local hospitals.

Methods

All patients with RAAS referred to a regional sarcoma service between 1998 and 2015 were identified from prospective databases. Patient records, and radiology, pathology and operation notes were reviewed retrospectively.

Results

Thirty-six patients were operated on with curative intent; 26 were managed by the sarcoma service (of whom 21 underwent radical excision of the irradiated field followed by chest wall reconstruction) and ten were managed locally. Median age was 69·5 (range 43–85) years. Disease-specific survival was significantly longer in patients managed by the sarcoma service than in those managed locally: median 91·1 (range 69·2–113·0) versus 48·8 (18·6–79·1) months respectively (P = 0·012). Overall survival rates were similar (P = 0·112). There was no difference in complete excision rate (18 of 26 in sarcoma service versus 5 of 10 in local services; P = 0·456), although the local recurrence rate was significantly lower among patients managed by the sarcoma service (9 of 26 versus 8 of 10; P = 0·015).

Conclusion

Specialist management of RAAS leads to fewer local recurrences and improved disease-specific survival. Early referral and management within specialist units is recommended.
Tricuspid regurgitation as a complication of Edwards Sapien XT valve implantation in pulmonary position a problem to deal with
Authors: Faccini Alessia , Butera Gianfranco
Published: February 2018

Nowadays, percutaneous pulmonary valve implantation (PPVI) is a suitable alternative to surgical procedure in patients with right ventricle outflow tract dysfunction. Two valves are currently available for PPVI: the Melody valve and the Edwards Sapien valve. The following complications may occur: coronary artery compression, deformation of the aortic root, stent or valve embolization, damage of distal pulmonary arteries, access site injuries. Here, we report on three cases of severe tricuspid regurgitation due to valvular and subvalvular apparatus damage during Edwards Sapien XT valve implantation.
Purification of Recombinant L‐Asparaginase II Using Solvent‐Freeze‐Out Technology
Authors: Yu Xiaoxi , Wu Yining , Huang Fang , Ulrich Joachim , Wang Jingkang
Published: February 2018

The purification of recombinant L‐asparaginase II from an Escherichia coli fermentation broth was carried out by using solvent‐freeze‐out technology on the lab scale. Preliminary crystallization conditions were determined by using batch crystallization screening. The purification of L‐asparaginase II was performed afterwards. Protein crystals with rhombic shape were obtained from the solvent‐freeze‐out crystallization using ethanol. The purity of the crystals was evaluated with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) together with UV spectrophotometry. It was found that DNA could be mostly removed by using solvent‐freeze‐out crystallization. Furthermore, the enzymatic activity was preserved.
Electrochemical Water Oxidation and Stereoselective Oxygen Atom Transfer Mediated by a Copper Complex
Authors: Kafentzi Maria‐Chrysanthi , Papadakis Raffaello , Gennarini Federica , Kochem Amélie , Iranzo Olga , Le Mest Yves , Le Poul Nicolas , Tron Thierry , Faure Bruno , Simaan A. Jalila , Réglier Marius
Published: February 2018

Water oxidation by copper‐based complexes to form dioxygen has attracted attention in recent years, with the aim of developing efficient and cheap catalysts for chemical energy storage. In addition, high‐valent metal–oxo species produced by the oxidation of metal complexes in the presence of water can be used to achieve substrate oxygenation with the use of H2O as an oxygen source. To date, this strategy has not been reported for copper complexes. Herein, a copper(II) complex, [(RPY2)Cu(OTf)2] (RPY2=N‐substituted bis[2‐pyridyl(ethylamine)] ligands; R=indane; OTf=triflate), is used. This complex, which contains an oxidizable substrate moiety (indane), is used as a tool to monitor an intramolecular oxygen atom transfer reaction. Electrochemical properties were investigated and, upon electrolysis at 1.30 V versus a normal hydrogen electrode (NHE), both dioxygen production and oxygenation of the indane moiety were observed. The ligand was oxidized in a highly diastereoselective manner, which indicated that the observed reactivity was mediated by metal‐centered reactive species. The pH dependence of the reactivity was monitored and correlated with speciation deduced from different techniques, ranging from potentiometric titrations to spectroscopic studies and DFT calculations. Water oxidation for dioxygen production occurs at neutral pH and is probably mediated by the oxidation of a mononuclear copper(II) precursor. It is achieved with a rather low overpotential (280 mV at pH 7), although with limited efficiency. On the other hand, oxygenation is maximum at pH 8–8.5 and is probably mediated by the electrochemical oxidation of an antiferromagnetically coupled dinuclear bis(μ‐hydroxo) copper(II) precursor. This constitutes the first example of copper‐centered oxidative water activation for a selective oxygenation reaction.
Current developments in immunotherapy in the treatment of multiple myeloma
Authors: Köhler Martin , Greil Christine , Hudecek Michael , Lonial Sagar , Raje Noopur , Wäsch Ralph , Engelhardt Monika
Published: February 2018

Multiple myeloma (MM) is the second most common hematologic malignancy and represents approximately 10% of all hematological neoplasms. Standard therapy consists of induction therapy followed by high‐dose chemotherapy and autologous stem cell transplantation (ASCT) or, if ASCT cannot be performed, standard doublet, triplet, or quadruplet, novel agent–containing induction treatment until progression. Although MM is still regarded as mostly incurable by current standards, the development of several novel compounds, combination therapies, and immunotherapy approaches has raised great hopes about transforming MM into an indolent, chronic disease and possibly achieving a cure for individual patients. Several new inhibitory and immunological agents have been approved or are under intensive investigation and may lead to new therapeutic options for patients with relapsed/refractory MM, for patients ineligible for ASCT, and for patients after ASCT. Especially in the field of immunotherapy, including monoclonal antibodies, checkpoint inhibition, and chimeric antigen receptor T cells, current advances are rapid and highly promising. This review aims to summarize the newest and most promising immunotherapeutic agents for MM, their clinical efficacy, their adverse event (AE) profiles, and the ways in which these AEs can best be overcome or avoided. Cancer 2018;124:2075‐85. © 2018 American Cancer Society.
Highly segregated localization of the functionally related vps10p receptors sortilin and SorCS2 during neurodevelopment
Authors: Boggild Simon , Molgaard Simon , Glerup Simon , Nyengaard Jens Randel
Published: February 2018

Nervous system development is a precisely orchestrated series of events requiring a multitude of intrinsic and extrinsic cues. Sortilin and SorCS2 are members of the Vps10p receptor family with complementary influence on some of these cues including the neurotrophins (NTs). However, the developmental time points where sortilin and SorCS2 exert their activities in conjunction or independently still remain unclear. In this study we present the characterization of the spatiotemporal expression pattern of sortilin and SorCS2 in the developing murine nervous system. Sortilin is highly expressed in the fetal nervous system with expression localized to distinct cell populations. Expression was high in neurons of the cortical plate and developing allocortex, as well as subpallial structures. Furthermore, the neuroepithelium lining the ventricles and the choroid plexus showed high expression of sortilin, together with the developing retina, spinal ganglia, and sympathetic ganglia. In contrast, SorCS2 was confined in a marked degree to the thalamus and, at E13.5, the floor plate from midbrain rostrally to spinal cord caudally. SorCS2 was also found in the ventricular zones of the ventral hippocampus and nucleus accumbens areas, in the meninges and in Schwann cells. Hence, sortilin and SorCS2 are extensively present in several distinct anatomical areas in the developing nervous system and are rarely co‐expressed. Possible functions of sortilin and SorCS2 pertain to NT signaling, axon guidance and beyond. The present data will form the basis for hypotheses and study designs for unravelling the functions of sortilin and SorCS2 during the establishment of neuronal structures and connections.
How do similarities in spatial distributions and interspecific associations affect the coexistence of Quercus species in the Baotianman National Nature Reserve, Henan, China
Authors: Yuan Zhiliang , Wei Boliang , Chen Yun , Jia Hongru , Wei Qingning , Ye Yongzhong
Published: February 2018

Congeneric species often have similar ecological characteristics and use similar resources. These similarities may make it easier for them to co‐occur in a similar habitat but may also lead to strong competitions that limit their coexistence. Hence, how do similarities in congeneric species affect their coexistence exactly? This study mainly used spatial point pattern analysis in two 1 hm2 plots in the Baotianman National Nature Reserve, Henan, China, to compare the similarities in spatial distributions and interspecific associations of Quercus species. Results revealed that Quercus species were all aggregated under the complete spatial randomness null model, and aggregations were weaker under the heterogeneous Poisson process null model in each plot. The interspecific associations of Quercus species to non‐Quercus species were very similar in Plot 1. However, they can be either positive or negative in different plots between the co‐occurring Quercus species. The spatial distributions of congeneric species, interspecific associations with non‐Quercus species, neighborhood richness around species, and species diversity were all different between the two plots. We found that congeneric species did have some similarities, and the closely related congeneric species can positive or negative associate with each other in different plots. The co‐occurring congeneric species may have different survival strategies in different habitats. On the one hand, competition among congenerics may lead to differentiation in resource utilization. On the other hand, their similar interspecific associations can strengthen their competitive ability and promote local exclusion to noncongeneric species to obtain more living space. Our results provide new knowledge for us to better understand the coexistence mechanisms of species.
Repurposing environmental DNA samples—detecting the western pearlshell (Margaritifera falcata) as a proof of concept
Authors: Dysthe Joseph C. , Rodgers Torrey , Franklin Thomas W. , Carim Kellie J. , Young Michael K. , McKelvey Kevin S. , Mock Karen E. , Schwartz Michael K.
Published: February 2018

Information on the distribution of multiple species in a common landscape is fundamental to effective conservation and management. However, distribution data are expensive to obtain and often limited to high‐profile species in a system. A recently developed technique, environmental DNA (eDNA) sampling, has been shown to be more sensitive than traditional detection methods for many aquatic species. A second and perhaps underappreciated benefit of eDNA sampling is that a sample originally collected to determine the presence of one species can be re‐analyzed to detect additional taxa without additional field effort. We developed an eDNA assay for the western pearlshell mussel (Margaritifera falcata) and evaluated its effectiveness by analyzing previously collected eDNA samples that were annotated with information including sample location and deposited in a central repository. The eDNA samples were initially collected to determine habitat occupancy by nonbenthic fish species at sites that were in the vicinity of locations recently occupied by western pearlshell. These repurposed eDNA samples produced results congruent with historical western pearlshell surveys and permitted a more precise delineation of the extent of local populations. That a sampling protocol designed to detect fish was also successful for detecting a freshwater mussel suggests that rapidly accumulating collections of eDNA samples can be repurposed to enhance the efficiency and cost‐effectiveness of aquatic biodiversity monitoring.
A taxonomic, functional, and phylogenetic perspective on the community assembly of passerine birds along an elevational gradient in southwest China
Authors: He Xuelian , Luo Kang , Brown Calum , Lin Luxiang
Published: February 2018

Integrating multiple facets of biodiversity to describe spatial and temporal distribution patterns is one way of revealing the mechanisms driving community assembly. We assessed the species, functional, and phylogenetic composition and structure of passerine bird communities along an elevational gradient both in wintering and breeding seasons in the Ailao Mountains, southwest China, in order to identify the dominant ecological processes structuring the communities and how these processes change with elevation and season. Our research confirms that the highest taxonomic diversity, and distinct community composition, was found in the moist evergreen broadleaf forest at high elevation in both seasons. Environmental filtering was the dominant force at high elevations with relatively cold and wet climatic conditions, while the observed value of mean pairwise functional and phylogenetic distances of low elevation was constantly higher than expectation in two seasons, suggested interspecific competition could play the key role at low elevations, perhaps because of relative rich resource result from complex vegetation structure and human‐induced disturbance. Across all elevations, there was a trend of decreasing intensity of environmental filtering whereas increasing interspecific competition from wintering season to breeding season. This was likely due to the increased resource availability but reproduction‐associated competition in the summer months. In general, there is a clear justification for conservation efforts to protect entire elevational gradients in the Ailao Mountains, given the distinct taxonomic, functional, and phylogenetic compositions and also elevational migration pattern in passerine bird communities.
Synthesis of N→Ga Coordinated Gallium(II)–Gallium(II) Compounds
Authors: Řičica Tomáš , Dostál Libor , Růžičková Zdeňka , Jambor Roman
Published: February 2018

Synthesis of the N→Ga coordinated gallium(II)–gallium(II) compounds containing the N,C,N‐chelating ligand L [L: {2,6‐(Me2NCH2)2C6H3}–] is reported. Attempts to stabilize the subvalent digallene [LGa]2 by reduction of [L(Cl)Ga]2 (1) or by hydrogen elimination from [L(H)Ga]2 (2) failed, but an unexpected complex, [L(C6H5CH2)Ga]2 (3), was isolated. It is possibly the product of the reaction of the parent digallene [LGa]2 with toluene.
One‐Pot Preparation of 3‐Arylisoxazole‐4,5‐dicarboxylates from Benzylic Chlorides and Acetylenedicarboxylates
Authors: Imai Taro , Togo Hideo
Published: February 2018

Various diethyl 3‐arylisoxazole‐4,5‐dicarboxylates were efficiently prepared in good to moderate yields by the successive treatment of benzylic chlorides and alkyl p‐tosylates with N‐methylmorpholine N‐oxide (NMO) and then hydroxylamine hydrochloride and potassium carbonate followed by Oxone® and diethyl acetylenedicarboxylates. This one‐pot proccess was carried out under mild, transition‐metal‐free conditions.
An Electrochemical Biosensor with Dual Signal Outputs for Ratiometric Monitoring the Levels of H2O2 and pH in the Microdialysates from a Rat Brain
Authors: Li Shuai , Tian Yang
Published: February 2018

The serious damage of ischemia to brain function has attracted extensive attention. As two of vital signal molecules, development of biosensors for monitoring of hydrogen peroxide (H2O2) and pH in vivo is significant to understand the roles of H2O2 and pH playing in rat brain followed by ischemia. Herein, a selective and accuracy ratiometric electrochemical biosensor was developed for quantifying H2O2 and pH through both current and potential outputs in a rat brain upon ischemia. Catalase (Cat) was first employed as a specific recognition element for both H2O2 and pH. Meanwhile, an inner reference molecule, ferrocene (Fc), independent of H2O2 and pH, was used as a built‐in correction to improve the accuracy. The reduction peak current of Cat increased with increasing concentration of H2O2 from 1.0 to 230 μM. Meanwhile, the peak potential negatively shifted with increasing pH from 5.91 to 7.81, resulting in determination of H2O2 and pH. Thus, combined with the remarkable analytical performance of the developed biosensor and the desirable biocompatibility of carbon fibre microelectrode (CFME), a direct and reliable approach was established to monitoring H2O2 and pH in the microdialysates collected from rat brain followed by cerebral ischemia.
Recent Advancements in Transition Metal‐Nitrogen‐Carbon Catalysts for Oxygen Reduction Reaction
Authors: Gu Wenling , Hu Liuyong , Li Jing , Wang Erkang
Published: February 2018

It remains a great challenge to replace platinum‐based catalysts with earth‐abundant materials to accelerate the sluggish oxygen reduction reaction (ORR) at the cathode, which is crucial for the future commercialization of fuel cells. Owing to the high catalytic activity, long‐term durability and low cost, transition metal‐nitrogen‐carbon (M−N/C, M=Fe, Co, Ni, Mn, etc) materials have been widely recognized as the most promising non‐precious metal catalysts (NPMCs) for ORR. In this review, the recent understanding of the ORR catalytic mechanism and the intrinsic nature of active sites is briefly introduced. Then, two crucial factors involved with careful selection of suitable M−N/C precursors and preferable control over the geometric structures of the catalysts are presented. Finally, we provide the insights into the remaining debates and challenges to illuminate the further development of ORR catalysts.
Extremal graphs for the k‐flower
Authors: Yuan Long‐Tu
Published: February 2018

The Turán number of a graph H, , is the maximum number of edges in any graph of order n that does not contain an H as a subgraph. A graph on vertices consisting of k triangles that intersect in exactly one common vertex is called a k‐fan, and a graph consisting of k cycles that intersect in exactly one common vertex is called a k‐flower. In this article, we determine the Turán number of any k‐flower containing at least one odd cycle and characterize all extremal graphs provided n is sufficiently large. Erdős, Füredi, Gould, and Gunderson determined the Turán number for the k‐fan. Our result is a generalization of their result. The addition aim of this article is to draw attention to a powerful tool, the so‐called progressive induction lemma of Simonovits.
Spectral modulation of stimulated Raman scattering signal: Beyond weak Raman pump limit
Authors: Lim Sohee , Chon Bonghwan , Rhee Hanju , Cho Minhaeng
Published: February 2018

Stimulated Raman scattering has recently been used in label‐free vibrational imaging studies of live cells. Important attempts to develop super‐resolution Raman imaging with intense Raman pump or decoherence beam have been made. However, the intense beams beyond weak stimulated Raman scattering limit could complicate spectral characteristics of Raman gain or loss signals. Here, the dependences of stimulated Raman loss signal on Raman pump intensity and pump‐probe delay time (Δt) are specifically investigated through both experimental and simulation studies. In the strong pump regime, a pronounced spectral modulation in stimulated Raman loss is observed at the Raman peaks of aromatic compounds with relatively large optical Kerr non‐linearity. We perform a numerical simulation for the coupled wave propagation to investigate the effect of cross‐phase modulation (XPM) on the stimulated Raman scattering (SRS). Our simulation involving both vibrationally resonant SRS and non‐resonant XPM effects in part accounts for the Δt‐dependent peak shift and spectral broadening as well as the appearance of a gain signal at negative time delays (Δt < 0). At the high pump intensity, it is found that the anti‐symmetric XPM signal with respect to the time zero (Δt = 0) cannot be selectively eliminated to produce pure SRS signal by time‐integration over Δt because of the increased interference term of the SRS and XPM at the Raman‐active frequency region. We believe that the experimental and simulation results discussed here would be of use in developing a super‐resolution coherent Raman imaging microscope in the near future.
Quantitative Raman spectroscopic study of the H2─CH4 gaseous system
Authors: Fang Jing , Chou I‐Ming , Chen Ying
Published: February 2018

The Raman spectra of pure H2 and CH4 gases and their 5 gaseous mixtures were collected at pressures from 1 to 40 MPa at ambient temperature. They were systematically analyzed in order to establish methodology for quantitative determination of composition and pressure of H2─CH4 bearing fluid inclusions. The peak positions of 4 vibrational bands of H2 in pure H2 gas decrease first and then increase after reaching their minima values at about 30 MPa. The wavenumbers of ʋ1 band of CH4 in pure CH4 gas decreases in wavenumber monotonically in the entire investigated pressure range. In H2─CH4 gaseous mixtures, both the peak positions of H2 and CH4 shift to lower wavenumbers with increasing pressure. The peak positions of ʋ1 band of CH4 can be used to determine the pressure of pure CH4 and CH4‐dominated fluids, where the peak position shifts are sufficiently large for precise pressure determination. The peak widths of H2 and CH4 in pure H2 and CH4 gases and H2─CH4 gaseous mixtures broaden as pressure increases. The peak area ratios and the peak height ratios between CH4 and H2 in H2─CH4 binary mixtures are sensitive to composition (i.e., molar ratio between CH4 and H2) but are almost independent of pressure. Thus, the peak area or peak height ratios can be used to determine the composition of H2─CH4 fluids. On the other hand, the peak height ratios of Q1(1) to Q1(3) bands in pure H2 gas or H2‐dominated gaseous mixtures are sensitive to pressure and insensitive to composition. Therefore, in H2‐dominated fluids, the relative peak heights of Q1(1) and Q1(3) of H2 is a better alternative for pressure determination. Based on our established Raman quantitative analysis method, we determined the composition and internal pressure of a natural H2─CH4‐bearing melt inclusion in quartz from Jiajika granite.
Anisotropic temperature‐dependence of optical phonons in layered PbI2
Authors: Zhang Zhaojun , Zheng Wei , Wang Weiliang , Zhong Dingyong , Huang Feng
Published: February 2018

The temperature‐dependence of wavenumbers of in‐plane E‐mode and out‐of‐plane A‐mode optical phonons of layered PbI2 were studied through analysis on its temperature‐dependent Raman spectra from 80 to 350 K. The temperature coefficient of the wavenumbers of in‐plane Eg phonon (−0.018 cm−1/K) and Eu phonon (−0.01 cm−1/K) are 3 and 10 times that of out‐of‐plane A1g phonon (−0.006 cm−1/K) and A2u phonon (−0.001 cm−1/K), respectively. Such anisotropy originated from the anisotropic thermal expansion of layered PbI2. These results will be beneficial for the design of PbI2‐based optoelectronic devices in the future.
Nondestructive prediction and visualization of plumpness in live Eriocheir sinensis using low‐field 1H magnetic resonance imaging
Authors: Zhang Hongcai , Mei Jun , Chen Shunsheng , Wu Xugan
Published: February 2018

BACKGROUND

The plumpness of hepatopancreas and gonad tissues in live Chinese mitten crabs (Eriocheir sinensis) depends on the grading scale and its commercial value. In this work, a low‐field T1‐weighted 1H magnetic resonance imaging (LF‐1H MRI) technique was developed to nondestructively analyze the plumpness of hepatopancreas and gonad tissues in live E. sinensis. Both male and female E. sinensis were characterized by two‐dimensional (2D) LF‐1H MRI. Moreover, a three‐dimensional (3D) LF‐1H MRI model that quantitatively integrated the total volume of lipid tissues in live E. sinensis was used.

RESULTS

The results showed 2D LF‐1H MRI could accurately discriminate the plumpness of hepatopancreas and gonad tissues in live E. sinensis. The results of the 3D LF‐1H MRI model displayed that the lipid volume of E. sinensis could be used to quantify lipid accumulation in lipid tissues.

CONCLUSION

LF‐1H MRI technology was successfully developed to accurately discriminate the development of E. sinensis hepatopancreas and gonad tissues in a nondestructive manner, indicating its application potential in grading commercial live crabs or advising crab farmers on breeding and fattening processes. © 2018 Society of Chemical Industry
Application of the ideal profile method to identify an ideal sufu for nonregular consumers
Authors: Chen Yan Ping , Chung Hau Yin
Published: February 2018

BACKGROUND

Sufu is a fermented soybean food with unique odor, flavor, and texture, which might not be appreciated by nonregular consumers. To identify the attributes that nonregular consumers appreciated, 12 commercial products bought from a Hong Kong market were tested by 113 consumers according to the ideal profile method (IPM), and rated on 22 attributes.

RESULTS

Data provided from nonregular consumers were consistent at both panel and consumer levels. The predicted ideal profile received a higher hedonic score (7.0) than the tested products (6.0). Compared with commercial samples, the ideal sufu has low intensity in the attributes of fermented (aroma and flavor), moldy (aroma), and hard (texture), but high intensity in the soybean‐like (aroma and flavor) and sesame oil‐like (aroma and flavor) attributes.

CONCLUSION

IPM could be used as an alternative approach to collect sensory profiles and preference data directly from consumers for product characterization. It could also be applied to identify the attributes that nonregular consumers appreciated. © 2018 Society of Chemical Industry
Graded contractions of filiform Lie algebras
Authors: Escobar José M. , Núñez Valdés Juan , Pérez‐Fernández Pedro
Published: February 2018

The study of contractions of Lie algebras is profusely extended in the last decades. In this paper we study the graded contractions of some lower‐dimensional filiform Lie algebras which have not been studied earlier. Particularly, we deal with graded contractions of model filiform Lie algebras of dimension less than or equal to 6 and with the ones of a nonmodel 6‐dimensional filiform Lie algebra.
An auto‐classification procedure for concealed weapon detection in millimeter‐wave radiometric imaging systems
Authors: Işiker Hakan , Ünal İlhami , Tekbaş Mustafa , Özdemir Caner
Published: February 2018

In this work, we developed and proposed an auto‐classification technique for concealed weapon detection (CWD) for passive millimeter‐wave (PMMW) imaging systems. This technique has the ability to detect, classify and image hidden objects beneath the cloth of human targets. The algorithm was based on segmentation of normalized gray‐scale images for raw passive millimeter‐wave captured images and employing a decisive criterion for the classification of the targets. First, we tested our algorithm with the simulated data that were created numerically. Next, we examined our CWD technique with the measured data that were collected with PMMW radiometric imaging system at Marmara Research Center of TÜBİTAK. After producing the raw passive radar images, we have applied our passive CWD technique to the measured raw images to assess the performance of the algorithm. Produced edge‐detected final images of the concealed objects provide successful operation of the proposed technique.
Design of compact UWB monopole planar antenna with modified partial ground plane
Authors: Sahoo Swarnaprava , Mishra Laxmi Prasad , Mohanty Mihir Narayan , Mishra Rabindra Kishore
Published: February 2018

In this article, an improved double‐sided printed compact UWB monopole planar radiator and a method for improving its bandwidth for ultra‐wideband application is suggested. Results show that using right angled triangular slots on the partial ground plane under the microstrip feed line (a patch radiator with a compact dimension of 14.5 × 14.75 mm2) is achieved a bandwidth of 14.3 GHz. It varies from 3.2 to 17.5 GHz for S11 < −10 dB (VSWR < 2) with center frequency of 10.35 GHz, whereas the measured bandwidth 14 GHz varies from 3.1 to 17.1 GHz. Moreover, it has a stable radiation pattern across the whole bandwidth and attains an average gain of 4.2 dBi and highest gain of 6.4 dBi at 12.5 GHz.
77 GHz phase‐locked loop for automobile radar system in 90‐nm CMOS technology
Authors: Lin Yo‐Sheng , Lan Kai‐Siang , Wang Chien‐Chin , Lin Hsin‐Chen
Published: February 2018

The design and implementation of a 77 GHz phase‐locked loop (PLL) for automobile radar system in 90 nm CMOS technology is demonstrated. To enhance the operation frequency range of the voltage‐controlled oscillator in the PLL, reversely tunable LC source degeneration technique is adopted. To improve the frequency locking range of the divide‐by‐3 injection‐locked frequency divider in the PLL, a parallel inductor is used to parallel resonate the parasitic capacitance of the cross‐coupled transistors. In addition, a phase and frequency detector with enhanced D flip flops is used to effectively reduce the dead zone. The PLL consumes only 49.6 mW and exhibits an operation range of 2.4 GHz (76.8∼79.2 GHz) and reference sidebands of <–56 dBc. The chip area of the PLL is only 0.656 mm2 excluding the test pads.
A design methodology of envelope tracking power amplifier based on harmonic impedance tuning
Authors: Huang Fei , Chen Wenhua , Zhang Qian , Li Jing , Lv Guansheng , Feng Zhenghe
Published: February 2018

A design methodology of utilizing the harmonic impedance tuning for the envelope tracking (ET) power amplifier (PA) is proposed in this letter. Owing to the assistance of harmonic tuning, the PA efficiency can be enhanced obviously. Experimental results show that PA prototype exhibits higher than 60% efficiency in the 7‐dB backoff power region and 36% average efficiency including envelope amplifier (EA) when driven by a 7‐dB PAPR long‐term evolution (LTE) signal.
An optimal operating frequency selection scheme for maximizing inductive power link efficiency
Authors: Cheng Yuhua , Xuan Dongdong , Su Xiang , Wu Wei , Wang Gaofeng
Published: February 2018

Improving the efficiency of the inductive wireless power transfer (WPT) is an effective way to increase the power transfer distance, reduce the power exposure, and popularize the WPT application. If the geometrical sizes of the transmitting and receiving coils and the distance between them have been determined, an operating frequency exists to maximize the power transfer efficiency. In this work, a method to find this optimal frequency is introduced by virtue of analytical models of self‐ and mutual‐inductances and parasitic resistances and capacitances of the coils, and verified via simulations and measurements.
A new compact dual band CP antenna design
Authors: Saygin Hasan , Rafiei Vahid , Karamzadeh Saeid
Published: February 2018

This article presents a novel compact size (20 mm × 16 mm × 0.8 mm) Tai‐chi‐shaped antenna for wireless applications. Dual frequency operation (3.14–4.58 GHz and 4.97–6.53 GHz) is achieved by optimizing the antenna during designing steps. The antenna gives circulary polarization from 3.26 to 4.42 GHz and from 5.45 to 6.63 GHz frequency ranges. The 4.2 dBic stable gain is another evident advantage of proposed work.
Proposal of a fractal geometry with double similarity ratio for application in frequency selective surfaces with insensitive resonance frequency as a function of cell periodicity
Authors: Dantas Sergio R. , Cadineli Erico Braz , Campos Antonio L. P. Siqueira , Gomes Neto Alfredo
Published: February 2018

In this article, we proposed a new fractal geometry with double similarity for application in frequency selective surfaces (FSS) to obtain a structure insensitive to the resonance frequency as a periodicity function. Therefore, the bandwidth can changes only by changing the FSS periodicity, without any changes to the resonance frequency. Simulations were performed with the ANSYS HFSS commercial software and two prototypes were built for validation purposes. A good convergence between numerical and experimental results was obtained.
Compact wideband filtering microstrip crossover with separated operating frequencies
Authors: Zhang Bo , Yu Cuiping , Wu Yongle , Liu Yuanan
Published: February 2018

In this article, a compact wideband crossover with filtering performance is presented, with separated operating frequencies in two transmission paths. First, a novel crossover core circuit is presented based on cross‐shaped coupled lines. The odd‐even mode method is adopted to extract the transmission and isolation characteristics. Then, the loading sections are added in the core circuit to construct the proposed crossover, which can achieve enhanced filtering and isolating performances. The detailed design procedures of specific crossover are presented. Finally, a wideband filtering crossover centered at 2.03 and 3.54 GHz with measured bandwidths of 0.6 and 0.62 GHz is fabricated and measured, which verifies the proposed structures well. As to isolate these two signal paths by adopting conventional crossover with same frequency, the operating bandwidth of crossover should be wider than 2.11 GHz with center frequency of 2.78 GHz.
Efficient compact monopole antenna for on‐body applications
Authors: Hamsagayathri P. , Sampath P.
Published: February 2018

This research paper presents the design and implementation of low profile printed monopole antenna for Bio medical applications. The proposed antenna is designed for industrial, scientific, and medical frequency band (2.4–2.48 GHz). Four different patch geometries are considered and their performance is analyzed. The various parameter studies on ground length and slot width is performed and the precise dimensions are chosen. The slotted geometry along with stepped ground plane increases the current path and reduces the antenna size. To alleviate the impedance matching, proposed structure is endowed with stub tuning and hence minimum return loss −31 dB is attained. The proposed antenna is built on FR4 substrate and overall dimension (l, w, h) of this antenna is 20 mm × 20 mm × 1.6 mm. Antenna simulations are performed using ADS. The performance parameters of the proposed antenna is examined through simulations and verified with measured data. The measured result shows good concurrence with the simulated results. The proposed antenna exhibits good isolation of −35 dB between co‐ and cross‐polarization. It has stable gain of 2.92 dBi over the frequency range of 2.4–2.48 GHz and achieves 98.6% radiation efficiency.
Design of broadband leaky‐wave antenna based on permeability‐negative transmission line
Authors: Yan Shi , Li Yuan Chang
Published: February 2018

In this paper, a planar broadband leaky‐wave antenna (LWA) has been designed to achieve a full‐space scanning property with a stable high gain. The proposed LWA consists of 9 permeability‐negative transmission line unit cells. With the use of the unit cell, the space harmonic with n = −2 mode in a wide frequency band is generated, and thus a scanning range from −90° to 0° is realized when one port of the LWA is excited and the other is connected to a matched load. Considering the symmetry of the proposed antenna structure, the scanning range from 0° to 90° can be achieved by exchanging the excitation port. A prototype was fabricated and measured. The experimental results show that the proposed LWA has an impedance bandwidth for SWR ≤ 2 from 11 to 17.5 GHz, a scanning range from −85° to +85°, and a stable gain of 10.7 ± 2 dB.
Wideband and low RCS planar circularly polarized array based on polarization conversion of metasurface
Authors: Zheng Qi , Guo Chenjiang , Ding Jun
Published: February 2018

In this article, a planar wideband circularly polarized (CP) slot antenna array based on metasurface (MS) with low radar cross section (RCS) is proposed. The array is comprised of
CP MS‐based antennas fed with a sequentially rotated feeding network. For each CP antenna, the CP radiation is achieved due to polarization conversion of the MS. Simultaneously, the total MS patches of the array can be viewed as checkerboard composed of MS array and mirror array. A
phase difference between the MS units and the mirror units ensures RCS reduction. Simulated results demonstrate that about 34.6% operating bandwidth in the frequency of 4.3–6.1 GHz (both S11
–10 dB and AR < 3 dB). In addition, over 5 dB RCS reduction is obtained in the entire operation band under normal incidence with respect to the array without MS for both x‐ and y‐polarizations. The simulated monostatic RCS less than −30.9 dBsm is observed at 5.0 GHz. A prototype of the array is fabricated and measured, which are in good agreement with simulated results.
Novel fluorosilicone thermoplastic vulcanizates prepared via core‐shell dynamic vulcanization: Effect of fluororubber/silicone rubber ratio on morphology, crystallization behavior, and mechanical properties
Authors: Chen Yukun , Gong Zhou , Cao Liming , Wang Youhong , Yuan Daosheng , Xu Chuanhui
Published: February 2018

Recently, we have reported a novel core‐shell dynamic vulcanization method to prepare poly(vinylidene fluoride) (PVDF)/fluororubber (FKM)/silicone rubber (SR) thermoplastic vulcanizates (TPVs) with cross‐linked rubber core‐shell particles. However, the shell thickness on the properties has not been studied in detail. Herein, these PVDF‐based TPVs different FKM‐shell thickness were prepared by changing FKM/SR ratios. The effect of FKM‐shell/SR‐core ratio on morphology, crystallization, and mechanical properties of the ternary TPVs was studied. The results showed that the FKM shell had more positive effect on interfacial‐induced crystallization behavior than the SR core due to its better compatibility with PVDF. When the FKM/SR ratio was <1, FKM was not enough to encapsulate SR completely, which resulted in the formation of imperfect core‐shell structure. However, when the FKM/SR ratio was >1, perfect core‐shell structure was formed. Therefore, the mechanical properties improved with increasing FKM content; especially, a remarkable improvement was observed when FKM/SR ratio was >1. This study could provide more information for the design of TPVs with core‐shell structure.
Synergistic toughening of nanocomposite hydrogel based on ultrasmall aluminum hydroxide nanoparticles and hydroxyapatite nanoparticles
Authors: Lei Yu , Zhang Gongzheng , Jiang Haoyang , Li Feibo , Liu Huanqing , Xia Yanhong , Zhang Yaqian , Xin Fangyun , Zhang Xiaoling , Li Huanjun
Published: February 2018

The development of hydrogels combining superior mechanical property attracts researchers' attention in recent years. Here, a novel nanocomposite hydrogel is prepared by one‐step photo‐polymerization of acrylic acid (AA) and N,N‐dimethylacrylamide (DMAA) in the presence of hydroxyapatite nanoparticles (HAp NPs) and aluminum hydroxide nanoparticles (Al(OH)3 NPs). The resulting transparent hydrogel exhibits ultrahigh toughness of 28.3 MJ m−3, high strength of 2.8 MPa, large elongation of 1300%, excellent self‐recovery and good biocompatibility. The crosslinking mechanism is contributed to the ionic coordination interaction between cations absorbing on the surface of nanoparticles and carboxyl groups of the polymer chain, and the synergistic toughening effect between HAp NPs and Al(OH)3 NPs is responsible for improving the strength and toughness simultaneously. Furthermore, this synergistic toughening strategy may provide a universal method for designing and constructing high strength nanocomposite hydrogels in many applications, especially for artificial cartilages. POLYM. COMPOS., 40:942–951, 2019. © 2018 Society of Plastics Engineers
Effect of amino acid addition on the micelle formation of the surface‐active ionic liquid 1‐tetradecyl‐3‐methylimidazolium bromide in aqueous solution
Authors: Rojas Mabel , Miskolczy Zsombor , Biczók László , Pavez Paulina
Published: February 2018

The effect of 3 amino acids on the self‐assembly properties of the surface‐active ionic liquid: 1‐tetradecyl‐3‐methyl imidazolium bromide, [C14mim][Br], was studied in neutral and basic aqueous solution. The critical micelle concentrations were determined by different techniques, and the thermodynamic parameters of micellization (ΔG0mic, ΔH0mic, and ΔS0mic) were measured by isothermal titration calorimetry.

The critical micelle concentration values decrease in the presence of all the amino acids used in this study. The most substantial effect was observed in the presence of L‐tryptophan at pH 12, due to the electrostatic and π‐π interactions with the imidazolium headgroup of the surfactant. Always entropy‐driven micellization occurred. Both the enthalpy and entropy changes upon association to micelles increased when the pH was enhanced from 7 to 12.

1H NMR measurements demonstrated that among the used amino acids, L‐tryptophan interacts most strongly with the headgroup of the surfactant cation.

The knowledge on the surfactant‐amino acid interactions significantly contributes to the deeper understanding of the effect of surfactants on the properties of peptides.
Registration‐free monitoring of multimode near‐circular shape profiles
Authors: Wang Kai , Li Jian , Tsung Fugee
Published: February 2018

Traditional shape profile monitoring of product geometric features mostly focuses on one type or mode of shapes in the discrete‐part manufacturing. Little attention has been paid to monitoring of multimode shape profiles, where different modes of shapes appear in a sample in the batch production process. Motivated by a real example of a powder material production process, we exploit the statistical process monitoring of multimode near‐circular shape profiles. First, we develop a feature extraction approach that is invariant to shape rotation and thus requires no registration for a mixture of different modes of shape profiles. The extracted feature vectors capture shape features well, based on which different modes of shape profiles are separated into several clusters. This enables us to build a Gaussian mixture model for the multimodality in the feature vector space. In process surveillance, a control chart is constructed based on the likelihood ratio test for detecting shifts in both the proportions and the shape features of multimode near‐circular shape profiles. Numerical simulations and real case studies demonstrate the effectiveness of our proposed chart.