bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the mitochondrial genome ofAnalcellicampa xanthosomagen. et sp. nov. (Hymenoptera: Tenthredinidae)
Authors: Niu Gengyun , Zhang Yaoyao , Li Zhenyi , Wei Meicai
Published: May 2019

A new genus with a new species of the tribe Hoplocampini of Hoplocampinae was described from China:Analcellicampa xanthosomaWei & Niu,gen. et sp. nov.Hoplocampa danfengensisG. Xiao 1994 was designated as the type species of the new genus. The characters ofAnalcellicampa danfengensis(G. Xiao)comb. nov.were briefly discussed. A key to the tribes and known genera of Hoplocampinae was provided. The nearly complete mitochondrial genome ofA. xanthosomawas characterized as having a length of 15,512 bp and containing 37 genes (22 tRNAs, 13 protein-coding genes (PCGs), and 2 rRNAs). The gene order of this new specimen was the same as that in the inferred insect ancestral mitochondrial genome. All PCGs were initiated by ATN codons and ended with TAA or T stop codons. All tRNAs had a typical cloverleaf secondary structure, except fortrnS1. Remarkably, the helices H991 ofrrnSand H47 ofrrnLwere redundant, while helix H563 ofrrnLwas highly conserved. A phylogeny based on previously reported symphytan mitochondrial genomes showed thatA. xanthosomais a sister group toMonocellicampa pruni, with high support values. We suggest thatA. xanthosomaandM. prunibelong to the tribe Hoplocampini of Hoplocampinae.
Capital social e desenvolvimento econômico: um estudo bibliométrico
Authors: Rech Munique , Clamer Roberto , Terribile Sandra Regina Isoton , Macke Janaina
Published: May 2019

O capital social contribui com o desenvolvimento das comunidades, uma vez que aspectos da cultura interagem com o desenvolvimento econômico. Porém, essa relação entre capital social e desenvolvimento econômico é recente na literatura, sendo reconhecida apenas após a definição de capital social feita por Robert Putnam, em 1995. O desenvolvimento até então considerava apenas variáveis econômicas, não abordando o capital social. O objetivo deste estudo é analisar a produção acadêmica sobre a relação entre capital social e desenvolvimento econômico, os principais autores que tratam o assunto, como evoluíram no tempo e seus desafios. Para tanto, foi desenhada uma pesquisa bibliométrica de caráter exploratório, na base de dados Science Direct. A pesquisa revelou 76 artigos, 16 dos quais foram escolhidos a partir do critério de livre acesso (os demais tinham o acesso restrito ao pagamento monetário). A análise da produção acadêmica revelou que esses temas começaram a ser tratados conjuntamente no ano de 2011, tendo o seu ápice em 2016, o que revela ser um assunto recente. Além disso, evidenciou-se que a maioria dos artigos é constituída de obras estrangeiras, o que pode estar relacionado à restrição de estudos e obras nacionais sobre o tema.
Comparative Study on Proximate, Mineral and Anti-Nutrient Content of Composite Roasted Corn Flour with Its Traditional Roasted Corn Counterpart for Homemade Complementary Foods
Authors: Paterne ROUGBO N’djoman , Gladys DOUE Ginette , Bernard SEHA Téhi , Anicet ENVIN Bogui
Published: May 2019

The present study aimed to produce and evaluate the physicochemical composition of an improved and enriched roasted corn flour with soybean (5%) and groundnut (5%) flours comparatively to its traditional preparation for homemade complementary foods. Samples of (corn, soybean and groundnut) were dried and milled to produce two types of roasted corn flour: the roasted corn flour with soy and peanut and the traditional roasted corn flour with corn only. Laboratory analyses of chemical proximate like nutrients, minerals and anti-nutrients properties were determined according to standard procedures. Data generated were subjected to one way analysis of variance using using SPSS 11.0 software. The results showed that there were significant differences (P<0.05) among the samples.

Regarding proximate composition, the composite roasted corn flour is distinguished by higher crude fat (5.83%), protein (19.66%), carbohydrate (62.31%), fiber (3.67%), ash (1.85%) and calorific (442.99 Kcal/100 g) value. Likewise, mineral contents increased significantly (p<0.05) in the composite roasted corn flour with high value in all the studied minerals including potassium (779.11 mg/100 g), phosphorus (242.83 mg/100 g), calcium (132.45 mg/100 g), zinc (2.67 mg/100 g) and iron (1.44 mg/100 g). The studied of anti-nutrients, showed that composite roasted corn flour also exhibit lower value in oxalate (8.03 mg/100 g) and phytic acid (3.48 mg/100 g). It could be concluded that the composite roasted corn flour appears to be suitable for homemade complementary foods to cover infant and young children needs.
On the General Linear Recursive Sequences
Authors: Kim Aeran
Published: May 2019

In this paper we investigate the properties of the general linear recursive sequences started from the Lucas sequence and give an application to matrices.
Clientele Satisfaction of Extension Services Provided by KVKs of Meghalaya
Authors: Dkhar Sao Evalwell , Devarani Loukham
Published: May 2019

The Krishi Vigyan Kendras (KVKs) are very important organisations for promoting agricultural development at the district level through the various trainings and other development programmes they offer. One way of knowing how effective these KVKs are in catalysing district agricultural development is to study the clienteles’ satisfaction of the farmers involved with those KVKs. In this study, 150 farmers across five districts of Meghalaya were interviewed to study the clienteles’ satisfaction, it was found that the client farmers of the KVKs were highly satisfied with the outputs and services of the KVKs since the overall clienteles’ satisfaction index was found to be 76.49. The farmers however did express a few problems such as non-timely delivery of relevant inputs/services, lack of innovative need based technologies and the lack of relevant market information. There should be more initiatives from the KVKs to provide regular market information to the farmers through the use of ICTs. Development programmes should be delivered timely so that farmers can plan their farming activities accordingly and more effort should be given by the KVKs to increase participation of farmers in programme planning and execution to help develop innovative need based solutions in accordance to the farmers’ problems.
Role of CCTV Camera Security Project on the Sustainability of Tourism Industry in Zanzibar: A Case of Old Stone Town, Urban West Region, Zanzibar
Authors: Mahmoud Ayoub Mohammed
Published: May 2019

This study reveals the less known role of CCTV camera security project on the sustainability of tourism industry in Zanzibar. This study attempted to answer the following three research questions: firstly what is the level of awareness of CCTV camera security project practices? secondly what are the impacts of CCTV camera security project on tourism industry? and thirdly what are the factors influencing the effectiveness of CCTV camera security project? The study applied a descriptive case study method of cross-sectional research design. Various data collection methods including observation, interviews and questionnaire survey were used to collect information from 120 respondents from the study area. The analysis of the collected qualitative and quantitative data was done through content analysis and descriptive statistics respectively. Based on the analyzed data, the findings revealed 33% of all 120 respondents were very much aware of CCTV camera security project practices in Zanzibar. Also the study revealed the presence of six major common types of crimes in the study area namely stealing, robbery, vehicles disorders, theft by servants, breaking and assault. The study findings further revealed the main impacts of CCTV camera security project on tourism industry including ensuring secured business environment, crime prevention, decline in private security costs and increase opening hours for business. The study finally concludes CCTV security project being of high usefulness in ensuring secured business environment. Finally the study recommends the use of public-private partnership model to enhance access and adoption of CCTV security cameras in many areas of Zanzibar.
An On-Farm Study for Feeding Impact of Total Mixed Ration (TMR) in Milking Cow
Authors: Sarker Nathu Ram , Yeasmin Dilruba , Tabassum Farah , Habib Md. Ahsan
Published: May 2019

Aims: To compare the compatibility of maize stover based Total Mixed Ration (TMR) over conventional feeding in terms of dry matter intake, milk production and composition and economic outcome from cows.

Study Design: CRD.

Place and Duration of Study: This field trial was carried out for a period of 60 days on 10 early lactating Holstein Friesian crossbred cows belonging to the farmers of Sirajgonj district.

Methodology: Cows were divided into two homogenous groups considering lactation status and yield. In control (T0) group, cows were provided conventional feeds comprising of 20.0 kg Napier grass, 5.0 kg paddy straw, 2 kg pelleted feed and 10.0 kg concentrate mixture (composed of 5 kg wheat bran, 2 kg pulse bran, 2 kg red gram bran and 1.0 kg oil cake), while in another group (T1), cows were fed TMR comprising of maize stover and concentrate with 50:50 proportions, according to their nutrient requirements. The DM and CP contents in concentrate mixture of T0 and T1 were 90.33% and 15.6% and 38.01% and 16.7%, respectively. The data were analyzed by "SPSS 20.0" statistical program.

Result: Fresh feed intakes were significantly (P<0.001) higher in T0 (37.4±0.008) than those of animals in T1; CP intakes were significantly (P=0.008) higher in T1 (1.60±0.02). Differences were not significant (P=0.07) in case of DMI and DMI on %live weight between two treatment groups. Milk yield and fat content significantly (P=0.05) differed between groups. Highest milk yield (9.99±0.07 kg) and milk fat (3.62±0.06%) were observed in cows of T1. However, milk protein, lactose and SNF did not vary significantly between groups. Considering milk price @BDT 60.0/ltr, profit gained maximum in T1 group.

Conclusion: TMR improved substantial amount of milk yield and quality with concurrent reduction of milk production cost.
Sensitivity of Cashew (Anacardium occidentale) Leaf Extract against Selected Urinary Tract Pathogens
Authors: Hassan I. A. , Abdulraheem I. , Emun H. O. , Shonowo O. M.
Published: May 2019

Aims: The study was carried out to investigate cashew extract as anti – urinary tract infection.

Methods: The leaves of cashew (Anacardium occidentale) were extracted using ethanol and distilled water; however the leaf extracts of cashew were screened for anti-microbial activities by the in vitro cup-plate method of agar diffusion technique with concentration of about 10-5 s cells/ml of the selected bacteria; using ethanol and distilled water as control. Simultaneously; the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the two extracts on selected bacteria were also determined.

Results: The minimum inhibitory concentration (MIC) of ethanolic and aqueous extract against the two organisms was 0.0625 g/l; namely E. coli and S. aureus except K. pneumoniae that occurred at 0.125 g/l. The two extracts were bactericidal at 0.25 g/l and above; below this concentration there were differentiations in the organism’s reaction to the extracts; for instance, the two extracts at 0.125 g/l were cidal; to the other two organisms; only K. pneumoniae was static. However at 0.0625g/l of the two extracts; the two organisms were static but K. pneumoniae showed growth.

Conclusion: Hence the leaf extract of Anacardium occidentale dissolved in distilled water and ethanol are good potential for the development of antibacterial drugs for urinary tract pathogens like Klebsiella pneumoniae, Escherichia coli and Staphylococcus aureus.
Assessment of Oral Health Knowledge, Attitude and Practice for Public Primary School Teachers in the City of Madinah, Saudi Arabia
Authors: Al-Johani Wejdan Ali , Elanbya May Gamar
Published: May 2019

Background: School teachers can play an important role in helping to instill good health habits in their students. Consequently, teachers need to have an adequate knowledge and a proper attitude regarding oral health.

Method and Materials: This is a cross sectional study conducted among public primary school teachers in Al-Madinah city. A questionnaire was distributed in 10 randomly selected schools. All teachers were asked to participate. Data was analyzed using SPSS software.

Results:  200 teachers were asked to participate all of them responded. 81% of the teachers were aware that caries are caused by bacteria in the oral cavity. 69.5% of teachers thinks that fluorides strength teeth. 44.5 % of the teachers brushed their teeth twice a day. Only 15% of the teachers regularly discuss oral health topics with their students. 74.5% of them think that it is necessary to treat tooth caries in primary teeth. 70.5% think that dental health education should be included in the primary school curriculum. 64% of them believed that schools should restrict the consumption of caries causing snacks during school hours.

Conclusion: Teachers’ knowledge regarding oral health needs improvement. Their own oral health practices are fair; however, their attitude towards oral health is very positive.
Estimation of primary radiation output for wide‐beam computed tomography scanner
Authors: Fukuda Atsushi , Lin Pei‐Jan P. , Ichikawa Nao , Matsubara Kosuke
Published: May 2019

Purpose

To estimate in‐air primary radiation output in a wide‐beam multidetector computed tomography (CT) scanner.

Materials and methods

A 6‐cc ionization chamber was placed free‐in‐air at the isocenter, and two sheets of lead (1‐mm thickness) were placed on the bottom of the gantry cover, forming apertures of 40–80 mm in increments of 8 mm. The air‐kerma rate profiles were measured with and without the apertures (, ) for 4.8 s at tube potentials of 80, 100, 120, and 135 kVp, tube current of 50 mA, and rotation time of 0.4 s. The nominal beam width was varied from 40 to 160 mm in increments of 40 mm. Upon completion of data acquisition, the were plotted as a function of the measured beam width, and the extrapolated dose rates () at zero beam width were calculated by second‐order least‐squares estimation. Similarly, the were plotted as a function of the radiation field (measured beam width × aperture size at the isocenter), and the extrapolated dose rates () were compared with the .

Results

The means and standard errors of the with 40‐, 80‐, 120‐, and 160‐mm nominal beam widths at 120 kVp were 10.94 ± 0.01, 11.13 ± 0.01, 11.22 ± 0.01, and 11.31 ± 0.01 mGy/s, respectively, and the was reduced to 10.67 ± 0.02 mGy/s. The of 40‐, 80‐, 120‐, and 160‐mm beam widths were reduced to 10.6 ± 0.1, 10.6 ± 0.2, 10.5 ± 0.1, and 10.6 ± 0.1 mGy/s and were not significantly different from the .

Conclusions

A method for describing the in‐air primary radiation output in a wide‐beam CT scanner was proposed that provides a means to characterize the scatter‐to‐primary ratio of the CT scanner.
Conjugated Polymer–Assisted Grain Boundary Passivation for Efficient Inverted Planar Perovskite Solar Cells
Authors: Chen Wei , Wang Yingfeng , Pang Guotao , Koh Chang Woo , Djurišić Aleksandra B. , Wu Yinghui , Tu Bao , Liu Fang‐zhou , Chen Rui , Woo Han Young , Guo Xugang , He Zhubing
Published: May 2019

Grain boundaries in lead halide perovskite films lead to increased recombination losses and decreased device stability under illumination due to defect‐mediated ion migration. The effect of a conjugated polymer additive, poly(bithiophene imide) (PBTI), is investigated in the antisolvent treatment step in the perovskite film deposition by comprehensive characterization of perovskite film properties and the performance of inverted planar perovskite solar cells (PSCs). PBTI is found to be incorporated within grain boundaries, which results in an improvement in perovskite film crystallinity and reduced defects. The successful defect passivation by PBTI yields reduces recombination losses and consequently increases power conversion efficiency (PCE). In addition, it gives rise to improved photoluminescence stability and improved PSC stability under illumination which can be attributed to reduced ion migration. The optimal devices exhibit a PCE of 20.67% compared to 18.89% of control devices without PBTI, while they retain over 70% of the initial efficiency after 600 h under 1 sun illumination compared to 56% for the control devices.
Humidity‐Tolerant Roll‐to‐Roll Fabrication of Perovskite Solar Cells via Polymer‐Additive‐Assisted Hot Slot Die Deposition
Authors: Kim Jueng‐Eun , Kim Seok‐Soon , Zuo Chuantian , Gao Mei , Vak Doojin , Kim Dong‐Yu
Published: May 2019

Heating‐assisted deposition is an industry‐friendly scalable deposition method. This manufacturing method is employed together with slot die coating to fabricate perovskite solar cells via a roll‐to‐roll process. The feasibility of the method is demonstrated after initial testing on a rigid substrate using a benchtop slot die coater in air. The fabricated solar cells exhibit power conversion efficiencies (PCEs) up to 14.7%. A nonelectroactive polymer additive is used with the perovskite formulation and found to improve its humidity tolerance significantly. These deposition parameters are also used in the roll‐to‐roll setup. The perovskite layer and other solution‐processed layers are slot die‐coated, and the fabricated device shows PCEs up to 11.7%, which is the highest efficiency obtained from a fully roll‐to‐roll processed perovskite solar cell to date.
Biodegradable Fe(III)@WS2‐PVP Nanocapsules for Redox Reaction and TME‐Enhanced Nanocatalytic, Photothermal, and Chemotherapy
Authors: Wu Chenyao , Wang Shige , Zhao Jiulong , Liu Yiyun , Zheng Yuting , Luo Yu , Ye Changqing , Huang Mingxian , Chen Hangrong
Published: May 2019

In this study, biocompatible Fe(III) species‐WS2‐polyvinylpyrrolidone (Fe(III) @ WS2‐PVP) nanocapsules with enhanced biodegradability and doxorubicin (DOX) loading capacity are one‐pot synthesized. In this nanocapsule, there exists a redox reaction between Fe(III) species and WS2 to form Fe2+ and WO42−. The formed Fe2+ could be oxidized to Fe3+, which reacts with Fe(III) @ WS2‐PVP again to continuously produce Fe2+ and WO42−. Such a repeated endogenous redox reaction leads to an enhanced biodegradation and DOX release of DOX @ Fe(III) @ WS2‐PVP. More strikingly, the Fe2+ generation and DOX release are further accelerated by the overexpressed H2O2 and the mild acidic tumor microenvironment (TME), since H2O2 and H+ can accelerate the oxidation of Fe2+. The continuously generated Fe2+ catalyzes a fast Fenton reaction with the innate H2O2 in tumor cells and produces abundant highly toxic hydroxyl radicals for nanocatalytic tumor therapy. Together with the high photothermal transforming capability, the DOX @ Fe(III) @WS2‐PVP nanocapsules successfully achieve the endogenous redox reaction and exogenous TME‐augmented tumor photothermal therapy, chemo and nanocatalytic therapy outcome. The concept of material design can be innovatively extended to the synthesis of biodegradable Fe(III) @ MoS2‐PVP nanocomposite, thus paving a promising novel way for the rational design of intelligent theranostic agents for highly efficient treatment of cancer.
Birnessite Nanosheet Arrays with High K Content as a High‐Capacity and Ultrastable Cathode for K‐Ion Batteries
Authors: Lin Baowei , Zhu Xiaohui , Fang Lingzhe , Liu Xinyi , Li Shuang , Zhai Teng , Xue Liang , Guo Qiubo , Xu Jing , Xia Hui
Published: May 2019

Potassium‐ion batteries (PIBs) are one of the emerging energy‐storage technologies due to the low cost of potassium and theoretically high energy density. However, the development of PIBs is hindered by the poor K+ transport kinetics and the structural instability of the cathode materials during K+ intercalation/deintercalation. In this work, birnessite nanosheet arrays with high K content (K0.77MnO2⋅0.23H2O) are prepared by “hydrothermal potassiation” as a potential cathode for PIBs, demonstrating ultrahigh reversible specific capacity of about 134 mAh g−1 at a current density of 100 mA g−1, as well as great rate capability (77 mAh g−1 at 1000 mA g−1) and superior cycling stability (80.5% capacity retention after 1000 cycles at 1000 mA g−1). With the introduction of adequate K+ ions in the interlayer, the K‐birnessite exhibits highly stabilized layered structure with highly reversible structure variation upon K+ intercalation/deintercalation. The practical feasibility of the K‐birnessite cathode in PIBs is further demonstrated by constructing full cells with a hard–soft composite carbon anode. This study highlights effective K+‐intercalation for birnessite to achieve superior K‐storage performance for PIBs, making it a general strategy for developing high‐performance cathodes in rechargeable batteries beyond lithium‐ion batteries.
Interfacial Thermal Contact Conductance inside the Graphene–Bi2Te3 Heterostructure
Authors: Pyun Kyung Rok , Kihm Kenneth David , Cheon Sosan , Kim Hong Goo , Lee Woomin , Lim Gyumin , Lee Woorim , Kim Sung‐Jin , Han Mi‐Kyung , Ko Seung Hwan
Published: May 2019

Graphene–Bi2Te3, a graphene‐based compound with a metal/metalloid heterostructure, is recently discovered to be a potentially novel thermoelectric material, demonstrating unprecedently enhanced thermoelectric efficiencies. The interfacial thermal transport must play an important role in determining the thermoelectric performance of this heterostructure. In particular, the interfacial thermal contact conductance (Gc) must be known in order to correctly elaborate the thermoelectric performances of graphene–Bi2Te3. Furthermore, the large nonlinear optoelectric response of this heterostructure redefines both the graphene thermal conductivity (kg) and its optical absorbance (Ag). A significantly suppressed Ag is predicted as low as 0.86% from its nominal value of 2.72% when suspended, from the transfer matrix calculations based on the Fresnel principle. Both Gc and kg are simultaneously determined from the optothermal Raman thermometry by duplexing the Raman data sets using two different objective magnifications (20× and 100×), which allows for the matching of the number of unknowns (Gc and kg) with the corresponding two Raman data sets. The thermal properties of Gc and kg for the graphene–Bi2Te3 heterostructure are first determined as 3.455 ± 0.619 × 106 W m−2 K−1 and 440.124 ± 76.265 W m−1 K−1, respectively.
Bioactive Antifouling Surfaces by Visible‐Light‐Triggered Polymerization
Authors: Kuzmyn Andriy R. , Nguyen Ai T. , Zuilhof Han , Baggerman Jacob
Published: May 2019

Hierarchical bioactive surfaces are created by visible‐light‐induced surface‐initiated living radical polymerization employing tris[2‐phenylpyridinato‐C2,N]iridium(III) as a photocatalyst. The hierarchical antifouling diblock copolymer structures consist of N‐(2‐hydroxypropyl)‐methacrylamide (first block) and carboxybetaine methacrylate (second block). The living nature of the polymerization is shown by a linear increase in layer thickness (as measured by atomic force microscopy) and reinitiation of the polymerization to create a patterned second block of polymer. The chemical structure of the brushes is confirmed by X‐ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy measurements. The block copolymer brushes demonstrate excellent antifouling properties when exposed to single‐protein solutions or to bovine serum. The second carboxybetaine block of the hierarchical antifouling structures can effectively be biofunctionalized with an anti‐fibrinogen antibody. The coated surfaces show a high affinity and specificity to fibrinogen, while preventing nonspecific adsorption from other proteins in bovine serum.
Light Emission by a Thermalized Ensemble of Emitters Coupled to a Resonant Structure
Authors: Wojszvzyk Léo , Monin Hector , Greffet Jean‐Jacques
Published: May 2019

Light emission by ensembles of emitters can be tailored using resonators such as cavities or plasmonic antennas. While concepts such as field enhancement, Purcell effect, and quenching can be used to understand the interplay between a two‐level system and a resonator, they fail to account for light emission by ensembles of emitters. Recent experiments reporting light emission by thermalized molecules, quantum dots, and hot electrons excited optically or electrically are reviewed. It is shown that the local Kirchhoff's law provides a unified framework to discuss photoluminescence, electroluminescence, and thermal radiation by ensembles of thermalized emitters coupled to resonators.
Surface Correction Control Based on Plasticized Multilayer P(VDF‐TrFE‐CFE) Actuator—Live Mirror
Authors: Thetpraphi Kritsadi , Le Minh Quyen , Houachtia Afef , Cottinet Pierre‐Jean , Petit Lionel , Audigier David , Kuhn Jeff , Moretto Gil , Capsal Jean‐Fabien
Published: May 2019

The interdisciplinary approach presented here creates next‐generation large mirrors using electroactive polymer (EAP) actuators without classical glass abrasive polishing (“live mirrors”). The outstanding electromechanical coupling properties of terpolymer are taken advantage of, particularly when doped with plasticizer, e.g., diisononyl phthalate (DINP). This doped terpolymer creates a large strain response as well as excellent mechanical energy density under relatively low electric fields. Classical EAPs (e.g., polyurethane, silicone) require extremely high input voltages to reach sufficient mechanical strain. Using the high‐permittivity doped terpolymer and the concept of stacking multilayers, high displacements and large forces are generated. The actuation performance of multilayered terpolymer filled with DINP has been proven to shape mirror glass with a preliminary prototype of an 8‐layer actuator stack. The experimental results demonstrate surface deformations under load conditions of several microns. This is large enough to usefully control large optical telescope mirrors. This technology may enable much larger high‐quality optical mirror systems for ground‐ and space‐based astronomy and communications telescopes.
Grating Diffraction or Bragg Diffraction? Coloration Mechanisms of the Photonic Ball
Authors: Ohnuki Ryosuke , Isoda Shinji , Sakai Miki , Takeoka Yukikazu , Yoshioka Shinya
Published: May 2019

The coloration mechanism of the photonic ball is investigated, which is a spherical aggregation of submicrometer‐sized colloidal particles. An interesting optical property is reported for photonic balls with colloidal particles larger than 400 nm: a ring‐like iridescent reflection appears on the peripheral part of the ball when observed under an optical microscope. Previous studies considered grating diffraction or Bragg diffraction separately to explain this iridescence. Here, it is shown from detailed structural and optical investigations that both diffraction mechanisms are important. In particular, Bragg diffraction explains the presence of a specific color for the photonic ball when observed with the naked eye in contrast to the iridescence seen under the microscope. The essential idea of the optical analysis is to combine the Bragg diffraction that occurs in the 3D periodic structure with the grating diffraction that originates from the surface with a 2D periodicity. The macroscopic color is almost independent of the angle of observation because of this unique reflection mechanism; hence, the photonic ball can be a suitable candidate for the structurally colored pigment.
Hybrid Digital Coding Metasurface for Independent Control of Propagating Surface and Spatial Waves
Authors: Wang Meng , Ma Hui Feng , Wu Liang Wei , Sun Shi , Tang Wen Xuan , Cui Tie Jun
Published: May 2019

A metasurface is a kind of planar metamaterial made by placing subwavelength‐scale structures into a 2D pattern on a surface or interface. It has been attracting much attention in recent years. In this paper, a concept for a hybrid digital coding metasurface is proposed that can manipulate the radiation of surface waves (SWs) and spatially propagating waves (SPWs), independently and simultaneously, in the same frequency band. By independently controlling the coding sequences of digital elements “0” and “1” for surface impedance and metasurface reflection phase, the SW radiation and SPW reflection can be reconfigured and manipulated in both the elevation and azimuth directions, respectively, with weak mutual coupling. To the best of our knowledge, this is the first attempt to simultaneously manipulate SW and SPW radiation using only a single metasurface with a shared aperture. Full‐wave simulations and experimental measurements are presented to validate the proposed theory and new physical phenomena.
Computational Dissection of 2D SiC7 Monolayer: A Direct Band Gap Semiconductor and High Power Conversion Efficiency
Authors: Guan Jintong , Zhang Lingyan , Deng Kaiming , Du Yongping , Kan Erjun
Published: May 2019

It is well known that zero‐gap character of graphene and silicene limits their applications, which stimulates the great passions to open an energy gap in graphene (silicene) and develop their application in optoelectronic devices. Recently, it is reported that SixC1 − x monolayers hold great potential in solar cells. In this paper, based on the global particle‐swarm optimization algorithm and the density functional theory methods, two new novel stable SiC7 (α‐SiC7 and β‐SiC7) was predicted, which are 22 meV per atom and 86 meV per atom lower than g‐SiC7 in energy, respectively. Among them, β‐SiC7 presents graphene‐like honeycomb configuration, having a direct band gap of 1.01 eV, which covers the main energy of the solar spectrum. Moreover, its hole mobility can reach ≈10 000 cm2 V−1 s−1, which is much higher than that of silicon. These advantages make it a promising candidate as a donor material for excitonic solar cells. The authors’ theoretical simulations show a considerably high power conversion efficiency of 20.5% for the primarily designed β‐SiC7/g‐SiC7 excitonic solar cells.
On the Origins of Fracture Toughness in Advanced Teleosts: How the Swordfish Sword's Bone Structure and Composition Allow for Slashing under Water to Kill or Stun Prey
Authors: Schmidt Felix N. , Zimmermann Elizabeth A. , Walsh Flynn , Plumeyer Christine , Schaible Eric , Fiedler Imke A. K. , Milovanovic Petar , Rößle Manfred , Amling Michael , Blanchet Clément , Gludovatz Bernd , Ritchie Robert O. , Busse Björn
Published: May 2019

The osseous sword of a swordfish (Xiphias gladius) is specialized to incapacitate prey with stunning blows. Considering the sword's growth and maturation pattern, aging from the sword's base to the tip, while missing a mechanosensitive osteocytic network, an in‐depth understanding of its mechanical properties and bone quality is lacking. Microstructural, compositional, and nanomechanical characteristics of the bone along the sword are investigated to reveal structural mechanisms accounting for its exceptional mechanical competence. The degree of mineralization, homogeneity, and particle size increase from the base toward the tip, reflecting aging along its length. Fracture experiments reveal that crack‐growth toughness vastly decreases at the highly and homogeneously mineralized tip, suggesting the importance of aging effects. Initiation toughness, however, is unchanged suggesting that aging effects on this hierarchical level are counteracted by constant mineral/fibril interaction. In conclusion, the sword of the swordfish provides an excellent model reflecting base‐to‐tip‐wise aging of bone, as indicated by increasing mineralization and decreasing crack‐growth toughness toward the tip. The hierarchical, structural, and compositional changes along the sword reflect peculiar prerequisites needed for resisting high mechanical loads. Further studies on advanced teleosts bone tissue may help to unravel structure–function relationships of heavily loaded skeletons lacking mechanosensing cells.
Low‐Conductance and Multilevel CMOS‐Integrated Nanoscale Oxide Memristors
Authors: Sheng Xia , Graves Catherine E. , Kumar Suhas , Li Xuema , Buchanan Brent , Zheng Le , Lam Sity , Li Can , Strachan John Paul
Published: May 2019

Using memristors, such as oxide and phase change resistive switches, as tunable resistors to construct analog computing hardware accelerators is gaining keen attention. Such accelerators have demonstrated the potential to significantly outperform digital computers in highly relevant applications such as machine learning and image processing. However, improvements in device‐level performance of memristors, including reducing power consumption and high current–induced metal migration in interconnects, need continued developments. Nanoscaling and complementary metal‐oxide semiconductor (CMOS) integration are also of significant importance in commercialization of such accelerators. Here tantalum oxide memristors scaled down to 25 nm sizes and integrated on CMOS transistor circuits are presented. The memristor conductance is programmable with a 6 order‐of‐magnitude operating range, especially with 3‐bits below 10 µS for low current operation. The stability of such levels and the size scaling of the operating parameters are further studied. These results will aid device engineering of memristors and bolster development of neuromorphic hardware accelerators.
Structural Anisotropy in Stretchable Silicon
Authors: Curtis Sabrina M. , Tompkins Randy P. , Nichols Barbara M. , Graziano Milena B. , Kierzewski Iain , Smith Gabriel , Leite Marina S. , Lazarus Nathan
Published: May 2019

Patterned planar silicon (Si) semiconductor structures able to conform around 3D surfaces are promising candidates for wearable devices from solar cells to displays. Despite the known anisotropic material properties of crystalline semiconductors, prior evaluations have assumed isotropic stretchable mechanical behavior. The effect of structural anisotropy on the mechanical stretching behavior of {100} single crystalline Si planes is demonstrated through models and experiments. 3D finite element analysis results show serpentines fabricated and strained loaded on the dense {111} family of planes will have maximum von Mises peak stresses that are 20% higher than those fabricated in the <100> direction on the {100} family of planes. A fabrication process is presented to release in‐plane Si serpentine test structures from (100) silicon‐on‐insulator wafers aligned parallel to the <110> and <100> crystallographic orientations. The released test structures can accommodate strains to 84%. Raman spectroscopy is used to characterize anisotropic effects on the internal stresses of Si serpentines. Raman measurements confirm two different maximum stress locations on <110> and <100> Si serpentines, resulting in two different break locations. All results show anisotropy plays a critical role in the mechanical behavior of stretchable Si serpentines and must be considered during design of stretchable semiconductor structures.
Highly Sensitive and Stretchable CNT‐Bridged AgNP Strain Sensor Based on TPU Electrospun Membrane for Human Motion Detection
Authors: Huang Jieyu , Li Dawei , Zhao Min , Mensah Alfred , Lv Pengfei , Tian Xiaojuan , Huang Fenglin , Ke Huizhen , Wei Qufu
Published: May 2019

Highly stretchable, conductive, and sensitive strain‐sensing materials have aroused wide interest owing to their potential in wearable devices. A facile and scalable method to fabricate a carbon‐nanotube‐ (CNT‐) bridged silver nanoparticles (AgNPs) strain sensor based on thermoplastic polyurethane electrospun membrane (TPUEM), which exhibits a large strain range with a high gauge factor simultaneously, is demonstrated. It exhibits a high stretchability with large workable strain range of up to 550%, high gauge factor of 7066, good durability over 1000 cycles, and comparable stability under various strains. Importantly, it can be used for human motion detection, including subtle movements and large‐scale human motion, showing its promising application in flexible and wearable devices.
Identifying Catalytic Active Sites of Trimolybdenum Phosphide (Mo3P) for Electrochemical Hydrogen Evolution
Authors: Kondori Alireza , Esmaeilirad Mohammadreza , Baskin Artem , Song Boao , Wei Jialiang , Chen Wei , Segre Carlo U. , Shahbazian‐Yassar Reza , Prendergast David , Asadi Mohammad
Published: May 2019

Solid‐state electrocatalysis plays a crucial role in the development of renewable energy to reshape current and future energy needs. However, finding an inexpensive and highly active catalyst to replace precious metals remains a big challenge for this technology. Here, tri‐molybdenum phosphide (Mo3P) is found as a promising nonprecious metal and earth‐abundant candidate with outstanding catalytic properties that can be used for electrocatalytic processes. The catalytic performance of Mo3P nanoparticles is tested in the hydrogen evolution reaction (HER). The results indicate an onset potential of as low as 21 mV, H2 formation rate, and exchange current density of 214.7 µmol s−1 g−1cat (at only 100 mV overpotential) and 279.07 µA cm−2, respectively, which are among the closest values yet observed to platinum. Combined atomic‐scale characterizations and computational studies confirm that high density of molybdenum (Mo) active sites at the surface with superior intrinsic electronic properties are mainly responsible for the remarkable HER performance. The density functional theory calculation results also confirm that the exceptional performance of Mo3P is due to neutral Gibbs free energy (ΔGH*) of the hydrogen (H) adsorption at above 1/2 monolayer (ML) coverage of the (110) surface, exceeding the performance of existing non‐noble metal catalysts for HER.
Testosterone moderates the effects of social support on cardiovascular disease risk factors among older US men
Authors: Gettler Lee T. , Sarma Mallika S. , Gengo Rieti G. , Oka Rahul C. , McKenna James J.
Published: May 2019

Objectives

Social support positively affects health through pathways such as shaping intrapersonal emotional and psychological well‐being. Lower testosterone often interrelates with psychological and behavioral orientations that are beneficial to participation in emotionally supportive relationships. Yet, little research has considered the ways in which testosterone may contribute to health outcomes related to emotional support.

Methods

We draw on testosterone, social support data, and cardiovascular disease (CVD)‐relevant indicators (inflammatory markers; blood pressure [BP]) from older men (n = 366) enrolled in the National Health and Nutrition Examination Survey, a US nationally representative study. We test whether men's testosterone moderates associations between emotional social support and markers related to CVD risk.

Results

For men with relatively lower testosterone, higher levels of social support predicted lower white blood cell (WBC) counts, consistent with reduced inflammation. In contrast, men with higher testosterone exhibited elevated WBC counts with greater support. In a diverging pattern, men with lower testosterone had higher systolic and diastolic BP with higher support, whereas the slopes for systolic and diastolic BP, respectively, were comparatively flatter for men with higher levels of testosterone.

Conclusions

We suggest that our findings are theoretically consistent with the idea that testosterone helps shape intrapersonal and interpersonal experiences and perceptions of men's emotional support networks, thereby affecting the health implications of that support. The somewhat divergent results for WBC count vs BP highlight the need for inclusion of other neuroendocrine markers alongside testosterone as well as refined measures of perceived and received support.
The different facets of “culture” in genetic counseling: A situated analysis of genetic counseling in Hong Kong
Authors: Zayts Olga , Shipman Hannah , Fung Jasmine L.‐F. , Liu Anthony P.‐Y. , Kwok Sit‐Yee , Tsai Anne C.‐H. , Yung Tak‐Cheung , Chung Brian H.‐Y.
Published: May 2019

In this article, we problematize the concept of “culture” in genetic counseling. With globalization and increased mobility of both genetic professionals and clients, there is an increased acknowledgement of the impact of “culture” on a counseling process. There is, however, little agreement on what “culture” is. The essentialist understanding that has long been dominant in the medical literature views culture as a set of shared beliefs, attitudes and practices among a group of people. Such an approach does not account for the individual differences and the dynamic nature of genetic counseling encounters. Following Zayts and Schnurr (2017), we use the distinction between two orders of culture: culture1 that refers to the static, generalized understanding of culture that is external to the specific context, and culture2, an analytic concept that denotes dynamic enactments of culture, emerging in the interaction. We use empirical data from genetic counseling sessions to illustrate these different facets of culture and to consider how and why speakers draw on them. The clinical implications of the study include highlighting the importance of cultural awareness among counselors, including cultural self‐awareness, and demonstrating how authentic interactional data could be used to enhance cultural training in genetic counseling.
A 1,3,2‐Diazaphospholene‐Catalyzed Reductive Claisen Rearrangement
Authors: Reed John H. , Donets Pavel A. , Miaskiewicz Solène , Cramer Nicolai
Published: May 2019

1,3,2‐Diazaphospholenes (DAPs) are an emerging class of organic hydrides. In this work, we exploited them as efficient catalysts for very mild reductive Claisen rearrangements. The method is tolerant towards a wide variety of functional groups and operates at ambient temperature. Besides being enantiospecific for substrates with existing stereogenic centers, the diastereoselectivity can be switched by varying solvents and DAP catalysts. The reaction kinetics show direct rearrangements of O‐bound phospholene enolates and provide a proof‐of‐principle for catalytic enantioselective reactions.
Revealing the correlation between molecular structure and dielectric properties of carbonyl‐containing polyimide dielectrics
Authors: Tong Hui , Ahmad Aftab , Fu Jing , Xu Hongyan , Fan Tao , Hou Yudong , Xu Ju
Published: May 2019

Polymer dielectrics with outstanding heat resistance and advanced dielectric properties are of great importance for high‐temperature capacitors in the applications of hostile circumstances. In this work, a series of aromatic carbonyl‐containing polyimides (CPI) are prepared from the carbonyl dianhydride and different diamines. The correlation between molecular structure (i.e., different linked structure (─O─, ─CH2─, ─SO2─) in diamines, the length of repeating unit and the linked position (para‐para or meta‐meta), and properties is revealed in detail to obtain CPI dielectrics with excellent thermal resistance (glass transition temperature, Tg: 241~352°C), reasonably high dielectric constant (3.99~5.23), low dissipation factor (0.00307~0.00395), and admirable breakdown strength (425~552 MV/m) simultaneously. Particularly, CPI‐5 with carbonyl structure in dianhydride and sulfonyl group in diamine proves to exhibit discharged energy density and charge–discharge efficiency of 6.34 J/cm3and 92.3% at 500 MV/m, respectively. In addition, CPI‐5 also displays stable dielectric properties in temperature range of −50‑200°C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47883.
Agricultural residue‐derived lignin as the filler of polylactic acid composites and the effect of lignin purity on the composite performance
Authors: Gao Yiwei , Qu Wangda , Liu Yang , Hu Hui , Cochran Eric , Bai Xianglan
Published: May 2019

In this study, corn stover lignin with different purities was used as filler in polylactic acid (PLA) matrix. It was found that the impurity metals present in unpurified lignin can significantly affect the performance of the composites in terms of their thermal stability, rheological behavior, mechanical properties, and hydrophobicity. Among the PLA composites, the ones fabricated with the lignin containing 4% of impurities overall had the best thermal stability and tensile strength. From melt rheology analysis, it was also found that the presence of the impurity metals decreases the complex viscosity of the composites. It is suggested that the impurity metals acted as catalysts to promote the interaction between lignin and PLA, resulting in an improved compatibility between PLA and the filler. In the present study, mechanical properties and hydrophobicity of the composites were further improved by acetylating the lignin with the optimum content of impurities. Tensile strength of the composite with the acetylated lignin was comparable to that of pure PLA, whereas the modulus increased to as high as 2.75 GPa. Overall, the study showed that unpurified lignin could be used as filler to achieve similar or better performance than the composites made with highly purified lignin fillers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47915.
Why is there a tilted cloud vertical structure associated with the northward advance of the East Asian summer monsoon
Authors: Sun Guorong , Li Yunying , Liu Lihang
Published: May 2019

The cloud fraction demonstrates an obvious northward‐tilting structure associated with the northward advance of the East Asian summer monsoon. As a follow‐up study, this study explores the physical explanation of the tilted structure based on ERA‐Interim data. The lower convergence center is located on the northern side of the convective center, and the upper divergence center is located on the southern side of the convective center. This specific atmospheric circulation promotes the formation of the tilted cloud vertical structure. Further study shows that the convective instability layer is thinner, and the convective available potential energy is smaller on the northern side of the convective center, favoring the formation of cumulus and altocumulus clouds in the lower troposphere. Condensation from cumulus convection releases latent heat, enhancing convective activity and generating an abundance of deep convective clouds. As the cloud anvils after deep convective clouds collapse, high clouds accumulate in the upper troposphere and are transported to the southern side of the convective center. Therefore, the observed clouds demonstrate a tilted structure. This study can be used to validate cloud vertical structure simulated by climate and weather models.
A machine learning approach for individual claims reserving in insurance
Authors: Baudry Maximilien , Robert Christian Y.
Published: May 2019

Accurate loss reserves are an important item in the financial statement of an insurance company and are mostly evaluated by macrolevel models with aggregate data in run‐off triangles. In recent years, a new set of literature has considered individual claims data and proposed parametric reserving models based on claim history profiles. In this paper, we present a nonparametric and flexible approach for estimating outstanding liabilities using all the covariates associated to the policy, its policyholder, and all the information received by the insurance company on the individual claims since its reporting date. We develop a machine learning–based method and explain how to build specific subsets of data for the machine learning algorithms to be trained and assessed on. The choice for a nonparametric model leads to new issues since the target variables (claim occurrence and claim severity) are right‐censored most of the time. The performance of our approach is evaluated by comparing the predictive values of the reserve estimates with their true values on simulated data. We compare our individual approach with the most used aggregate data method, namely, chain ladder, with respect to the bias and the variance of the estimates. We also provide a short real case study based on a Dutch loan insurance portfolio.
Why Global Standards for Calibration of Water Distribution Models Won't Work
Authors: Walski Thomas
Published: May 2019

You would think it would be easy to develop numerical standards for model calibration. It isn't.