bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot Deep Drawing Processing of Titanium Sheet Metal Parts for High Temperature Applications
Authors: Nawaya Tarik , von Hehl Axel , Wagner Sabine , Beck Werner
Published: October 2018

Hot deep drawing (HDD) is an innovative promising compromise to reduce costs by saving production time and to reduce the expenses for surface treatment. Parts made by HDD provide a high accuracy and constant wall thickness suitable for automated industrial assembly. In this paper, the behavior of one near‐α titanium alloy, used to manufacture the components of exhaust systems, are observed during HDD. It aims at improving the mechanical properties of the formed component by means of an integrated annealing to prevent, or at least minimize, the spring back behavior. For this purpose, the parameters of HDD followed by the so‐called creep relaxation period are optimized. They are: heating time, forming temperature, creep strain, strain rate, and relaxation time. Based on a statistical experimental design, the experimental procedure are conducted by utilizing a forming dilatometer. The results reveal a considerable impact of relaxation time on the material behavior. In addition, variation of the strain rate has also an effect on the considered outputs. Regarding the aforementioned challenges, a set of parameter is suggested, with which all the expected drawbacks can be diminished.
Electron Beam Welding and Characterization of Dissimilar Joints with TWIP Matrix Composites
Authors: Halbauer Lars , Laubstein Rudy , Radajewski Markus , Buchwalder Anja , Krüger Lutz , Biermann Horst
Published: October 2018

Welding of Mg‐PSZ‐reinforced TWIP metal matrix composites (TWIP MMC) requires precise control over the level of dilution: otherwise, the risk of cavity formation arises. For this work, dissimilar joints between a TWIP MMC and an AISI 304 stainless steel are produced by means of electron beam welding over a wide range of process parameters. The influence of the welding process on the dilution, the microstructure of the welding seam, and the mechanical properties is presented and classified according to DIN EN ISO 13919–1. Furthermore, the welding quality of the samples is characterized by non‐destructive testing methods such as the novel uit and X‐ray analysis. It is shown that joints with EG ≥ ‘C’ can be produced with a high degree of reproducibility within a parameter window of Δx = 0.40.6 mm at welding speeds of 15 and 5 mm s−1. The main defects are cavities, underfill, and lack of fusion which can all be detected by the uit down to a minimum defect size of 90–100 µm. Lower welding speeds and a slight underfocus decrease the tendency toward defects and for a (Δx) = 0.5 mm, tensile properties are achieved to match the level of the TWIP MMC.
Four Degrees‐of‐Freedom Direct Writing of Liquid Metal Patterns on Uneven Surfaces
Authors: Yoon Young , Kim Shinmyoung , Kim Doyoon , Kauh Sang Ken , Lee Jungchul
Published: October 2018

A novel direct writing of eutectic gallium indium (EGaIn) patterns on uneven surfaces including both inclined and curved substrates is reported. The approach relies on four degrees‐of‐freedom motion control of the pressurized EGaIn dispenser and precise sensing of the dispenser tip–substrate distance. An experimental hardware is built by using three motorized linear stages, a motorized rotation stage, two electronic pressure regulators, and a laser distance sensor and operating programs are developed. While the rotation stage makes the laser sensor always precede the dispenser tip by a predetermined value, the vertical stage maintains the dispenser tip–substrate distance by using the readout of the laser sensor recorded beforehand. By incorporating the time delay from the laser sensor preceding the dispenser tip for feedback control of the dispenser tip position, various EGaIn patterns are directly written on uneven substrates with their widths being 70–80 µm. Electrical connectivity and structural integrity of written EGaIn patterns are confirmed by the light‐emitting diode mounted between two end segments of EGaIn patterns. The maximum slope for reliable patterning is found to be ≈20°. To show practical applications of this new concept, a curved keypad and a glove‐type wearable device with strain sensors integrated are demonstrated.
Study of the influence of initiator content in the polymerization reaction of a thermoplastic liquid resin for advanced composite manufacturing
Authors: Raponi Olivia de Andrade , Barbosa Lorena Cristina Miranda , de Souza Bárbara Righetti , Ancelotti Junior Antonio Carlos
Published: October 2018

Considerable interest has been generated in the last years in the use of thermoplastics polymers as matrices in advanced composites manufacturing. In this research, a new Elium® acrylic matrix developed by Arkema has been studied to evaluate the influence of different benzoyl peroxide initiator (Luperox®78) contents on the polymerization reactions for Elium®150. For that, thermal and rheological analyses were performed providing a better understanding of these reactions. The results show that the initiator concentration and temperature affect the resin's properties not only in the initiation step, but also in the resin's complete polymerization reaction. Besides that, it was observed that the initiator concentration can also affect the polymer chain lengths, which may lead to variations in the dynamic mechanical properties and thermal stability of the polymer.
Male–female interactions in multimale groups of mountain gorillas
Authors: Habumuremyi Sosthene , Deschner Tobias , Fawcett Katie A. , Robbins Martha M.
Published: October 2018

Male–female social interactions may vary according to female receptivity, female parity, and male dominance rank. Such variation may be less apparent in species with one‐male mating systems than those with multimale mating systems, as within‐group male–male competition and female mate choice are absent. Examining variation in male–female interactions in multimale groups in species with a predominantly one‐male mating system may help to shed light on plasticity in behavioral patterns and the evolution of mating systems. In this study, we investigated the effect of female receptivity (i.e., days when mating occurred), female parity, and male dominance rank on the patterns of spatial proximity, grooming, following, and aggression among 34 male–female dyads in four multi‐male groups of Virunga mountain gorillas. In addition, as a preliminary investigation of potential physiological costs incurred by females in a mating context (coercion), we tested whether female receptivity and female parity explained variation in immunoreactive glucocorticoid (iGC) levels of females. The amount of time male–female dyads spent in close proximity was significantly higher for parous versus nulliparous females and for high‐ versus low‐ranking males. The rate of male aggression to females did not vary significantly with female parity, male rank, or female receptivity. However, post hoc analysis showed that both proximity and aggression increased for the males that participated in the matings on days that females were receptive. Grooming and following by males occurred infrequently. Neither female receptivity nor parity influenced iGC levels in females, a finding that is more consistent with courtship than coercion of females by males. Overall, our results suggest that males advertise their ability to provide protection to females and their offspring, and females seek out males that can do so.
Energetic constraints on the reproduction of female mantled howlers
Authors: Rangel‐Negrín Ariadna , Coyohua‐Fuentes Alejandro , Chavira‐Ramírez David R. , Canales‐Espinosa Domingo , Dias Pedro Américo D.
Published: October 2018

The reproductive process of female primates is energetically constrained. However, while there is extensive evidence about factors that influence the maintenance of gestation and lactation, less is known about energetic correlates of cycling and the occurrence of conception in wild primates. We examined how female physical condition affected the occurrence of conception and interbirth intervals (IBI) in female mantled howler monkeys, a species in which females experience long non‐conceptive periods. For 6 years we followed 7 females at La Flor de Catemaco (Los Tuxtlas, Mexico). In addition to noting the presence of dependent immatures, we collected fecal samples that were analyzed for thyroid hormone and glucocorticoid metabolite concentrations (N = 1,460). Conception was more likely following months when females were not lactating and had higher thyroid hormone and lower glucocorticoid levels. IBIs were shorter when females had higher thyroid hormone and lower glucocorticoid levels, and when the infant at the beginning of the interval died. Due to their obvious impact on female fecundity and fertility, gestation and lactation are the stages of the reproductive process that have traditionally received more attention in studies of female reproductive performance. Still, the cycling stage accounts for a large proportion of IBIs in many primate species. Here we demonstrate that the reproductive rates of female mantled howler monkeys are energetically constrained: both the occurrence of conception and IBI are positively affected by female energetic condition.
Chiral Lewis Acid Catalyzed Reactions of α‐Diazoester Derivatives: Construction of Dimeric Polycyclic Compounds
Authors: Tan Fei , Liu Xiaohua , Wang Yan , Dong Shunxi , Yu Han , Feng Xiaoming
Published: October 2018

An unexpected homologation/dyotropic rearrangement/interconversion/[3+2] cycloaddition cascade reaction of α‐diazoester‐terminated N‐propyl‐substituted isatin derivatives was achieved in the presence of a chiral N,N′‐dioxide/ScIII catalyst. This catalytic manifold allows rapid construction of several classes of dimeric polycyclic compounds with good yields and high levels of diastereo‐ and enantioselectivity (up to 99 % ee). Furthermore, macrocyclic dimers can be obtained by an intermolecular homologation process.
Struktur und Reaktivität der Al‐O(H)‐Al‐Einheiten in Siloxidgerüstverbindungen – Modellstudien in Lösung und in Isolation
Authors: Lokare Kapil Shyam , Braun‐Cula Beatrice , Limberg Christian , Jorewitz Marcel , Kelly John T. , Asmis Knut R. , Leach Stephen , Baldauf Carsten , Goikoetxea Itziar , Sauer Joachim
Published: October 2018

Obwohl Aluminiumoxide und Aluminosilicate in vielen Bereichen eingesetzt werden, bleiben deren Oberflächenheterogenität und insbesondere das Defektverhalten nach Hydroxylierung/Dehydroxylierung auf molekularer Ebene weitestgehend unverstanden. Wir untersuchen die molekulare Modellverbindung [Al3(μ2‐OH)3(THF)3(PhSi(OSiPh2O)3)2], 1, um die Säure‐Base‐Reaktivität von cyclischen Al3(μ2‐OH)3‐Einheiten aufzuklären. Wir können zeigen, dass 1, ähnlich wie Zeolithe, eine ausreichende Acidität aufweist, um die Isomerisierung von Olefinen zu katalysieren. Simulationen und Gasphasen‐Schwingungsspektroskopie an lösungsmittelfreiem und deprotoniertem 1 zeigen, dass die Deprotonierung einer Hydroxygruppe die sechsgliedrige Ringstruktur des Al3(μ2‐OH)3‐Kerns destabilisiert und in eine Struktur aus zwei kantenverknüpften viergliedrigen Ringen umlagert. Dies macht AlIV‐O(H)‐AlIV‐Einheiten zu stark sauren Funktionalitäten, und alle Ergebnisse zusammen legen nahe, dass ihre Acidität mit derjenigen zeolithischer SiIV‐O(H)‐AlIV‐Gruppen vergleichbar ist.
Enabling Visible‐Light‐Driven Selective CO2 Reduction by Doping Quantum Dots: Trapping Electrons and Suppressing H2 Evolution
Authors: Wang Jin , Xia Tong , Wang Lei , Zheng Xusheng , Qi Zeming , Gao Chao , Zhu Junfa , Li Zhengquan , Xu Hangxun , Xiong Yujie
Published: October 2018

Quantum dots (QDs), a class of promising candidates for harvesting visible light, generally exhibit low activity and selectivity towards photocatalytic CO2 reduction. Functionalizing QDs with metal complexes (or metal cations through ligands) is a widely used strategy for improving their catalytic activity; however, the resulting systems still suffer from low selectivity and stability in CO2 reduction. Herein, we report that doping CdS QDs with transition‐metal sites can overcome these limitations and provide a system that enables highly selective photocatalytic reactions of CO2 with H2O (100 % selectivity to CO and CH4), with excellent durability over 60 h. Doping Ni sites into the CdS lattice leads to effective trapping of photoexcited electrons at surface catalytic sites and substantial suppression of H2 evolution. The method reported here can be extended to various transition‐metal sites, and offers new opportunities for exploring QD‐based earth‐abundant photocatalysts.
Ein NiII‐haltiges Vitamin‐B12‐Derivat mit einem Kofaktor‐F430‐artigen π‐System
Authors: Brenig Christopher , Prieto Lucas , Oetterli René , Zelder Felix
Published: October 2018

F430, ein einzigartiger enzymatischer Kofaktor, ist an der Bildung und Oxidation von Methan in streng anaeroben Bakterien beteiligt. Das Schlüsselenzym Methyl‐Koenzym‐M‐Reduktase (MCR) weist in seinem aktiven Zentrum einen porphinoiden Nickel‐Komplex auf, der ein charakteristisches Absorptionsmaximum bei etwa 430 nm zeigt. Hier berichten wir über die dreistufige, von Vitamin B12 ausgehende Partialsynthese eines hybriden NiII‐haltigen Corrins, dessen strukturelle und spektroskopische Eigenschaften teilweise denen von F430 ähneln. Schlüsselschritt der Syntheseroute ist die simultane Demetallierung und Ringschlussreaktion eines 5,6‐Secocobalamins zum metallfreien 5,6‐Dihydroxy‐5,6‐dihydrohydrogenobalamin mittels Cobaltocen und KCN unter reduktiven Bedingungen. Untersuchungen zur Koordinationschemie der neuartigen Verbindung untermauern die frühere Hypothese, warum die natürliche Selektion des Corphinliganden gegenüber dem Corrinliganden in F430 es ermöglichte, anspruchsvolle Ni‐katalysierte Reaktionen in biologischen Systemen durchzuführen.
Reliability of acoustic tomography and ground‐penetrating radar for tree decay detection
Authors: Wu Xi , Li Guanghui , Jiao Zhi , Wang Xiping
Published: October 2018

Premise of the Study

Various nondestructive testing technologies have been used for detecting and visualizing internal defects in urban trees. The results obtained by using different nondestructive testing tools can be interpreted in different ways, which may result in inaccurate assessment of the true condition of the inspected trees. The main objective of this study was to evaluate the reliability of acoustic tomography and ground‐penetrating radar (GPR) technology for detecting internal decay in a number of different tree species.

Methods

One hundred and forty‐seven individual trees of 33 species were inspected at a historic park in Yangzhou, Jiangsu Province, China, using a combination of visual inspection, acoustic tomography, GPR scanning, and resistance micro‐drilling methods. Special image processing procedures were developed to analyze the acoustic and radar images and to estimate the proportion of compromised wood.

Results

The acoustic tomography tests revealed 10 defective trees with acoustic shadows suggesting compromised wood in more than 10% of the cross‐section area. The actual nature of these defects on living trees can be ascertained by conducting resistance micro‐drilling at selected paths. The Tree Radar Unit (TRU) System produced 85% false positive predictions and thus was not successful in visualizing the true physical conditions of the trees.

Conclusions

Acoustic tomography can successfully detect trees with internal decay and cavities. A combination of visual inspection, acoustic tomography, and resistance micro‐drilling is an effective approach to detect, measure, and visualize internal defects on a diversity of tree species. The image processing procedures we developed make possible the quantitative analysis of compromised wood and could improve the science‐based tree risk assessment process. In contrast, the TRU System presented challenges in field applications, particularly on trees with small diameters and irregularly shaped trunks. The images obtained in this study using the TRU system were largely inaccurate and not reliable for tree inspection.
Olfactory attraction mediated by the maxillary palps in the striped fruit fly, Bactrocera scutellata: Electrophysiological and behavioral study
Authors: Park Kye Chung , Jeong Seon Ah , Kwon Gimyon , Oh Hyun‐Woo
Published: October 2018

Here, we report that the olfactory attraction of the striped fruit fly, Bactrocera scutellata (Hendel; Diptera: Tephritidae), a serious pest of pumpkin and other cucurbitaceae plants, to cue lure and raspberry ketone is mediated by the maxillary palps. The antennae, bearing three morphological types (basiconic, trichoid, and coeloconic) of olfactory sensilla, in male and female
B. scutellata exhibited significant electroantennogram (EAG) responses to a plant volatile compound, 3‐octanone, and methyl eugenol, whereas cue lure, raspberry ketone, and zingerone that are known to attract several other species of
Bactrocera fruit flies elicited no significant EAG responses from both sexes. In contrast, maxillary palps, housing one morphological type of basiconic sensilla, displayed the largest electropalpogram (EPG) responses to cue lure followed by raspberry ketone among the five compounds tested in male and female
B. scutellata, with only minor EPG responses to 3‐octanone, which indicates that the maxillary palps are responsible for detecting cue lure and raspberry ketone in this species. In field trapping experiments, significant number of male
B. scutellata were captured in the traps baited with cue lure or raspberry ketone, in which the attractiveness of cue lure was significantly higher than that of raspberry ketone. Methyl eugenol and zingerone were not behaviorally attractive to
B. scutellata although they elicited significant EPG responses. Our study indicates that the behavioral attraction of
B. scutellata to cue lure and raspberry ketone is mediated by the olfactory sensory neurons present in the maxillary palps.
Pulsed electromagnetic fields prevented the decrease of bone formation in hindlimb‐suspended rats by activating sAC/cAMP/PKA/CREB signaling pathway
Authors: Li Wen‐Yuan , Li Xue‐Yan , Tian Yong‐Hui , Chen Xin‐Ru , Zhou Jian , Zhu Bao‐Ying , Xi Hui‐Rong , Gao Yu‐Hai , Xian Cory J , Chen Ke‐Ming
Published: October 2018

Microgravity is one of the main threats to the health of astronauts. Pulsed electromagnetic fields (PEMFs) have been considered as one of the potential countermeasures for bone loss induced by space flight. However, the optimal therapeutic parameters of PEMFs have not been obtained and the action mechanism is still largely unknown. In this study, a set of optimal therapeutic parameters for PEMFs (50 Hz, 0.6 mT 50% duty cycle and 90 min/day) selected based on high‐throughput screening with cultured osteoblasts was used to prevent bone loss in rats induced by hindlimb suspension, a commonly accepted animal model to simulate the space environment. It was found that hindlimb suspension for 4 weeks led to significant decreases in femoral and vertebral bone mineral density (BMD) and their maximal loads, severe deterioration in bone micro‐structure, and decreases in levels of bone formation markers and increases in bone resorption markers. PEMF treatment prevented about 50% of the decreased BMD and maximal loads, preserved the microstructure of cancellous bone and thickness of cortical bone, and inhibited decreases in bone formation markers. Histological analyses revealed that PEMFs significantly alleviated the reduction in osteoblast number and inhibited the increase in adipocyte number in the bone marrow. PEMFs also blocked decreases in serum levels of parathyroid hormone and its downstream signal molecule cAMP, and maintained the phosphorylation levels of protein kinase A (PKA) and cAMP response element‐binding protein (CREB). The expression level of soluble adenylyl cyclases (sAC) was also maintained. It therefore can be concluded that PEMFs partially prevented the bone loss induced by weightless environment by maintaining bone formation through signaling of the sAC/cAMP/PKA/CREB pathway. Bioelectromagnetics. 39:569–584, 2018. © 2018 Wiley Periodicals, Inc.
In Vitro Bone Cell Response to Tensile Mechanical Solicitations: Is There an Optimal Protocol?
Authors: Baudequin Timothée , Legallais Cécile , Bedoui Fahmi
Published: October 2018

Bone remodeling is strongly linked to external mechanical signals. Such stimuli are widely used in vitro for bone tissue engineering by applying mechanical solicitations to cell cultures so as to trigger specific cell responses. However, the literature highlights considerable variability in devices and protocols. Here the major biological, mechanical, and technical parameters implemented for in vitro tensile loading applications are reviewed. The objective is to identify which values are used most, and whether there is an optimal protocol to obtain a functional tissue‐engineering construct. First, a shift that occurred from fundamental comprehension of bone formation, to its application in rebuilt tissues and clinical fields is shown. Despite the lack of standardized protocols, consensual conditions relevant for in vitro bone development, in particular cell differentiation, could be highlighted. Culture processes are guided by physiological considerations, although out‐of‐range conditions are sometimes used without implying negative results for the development of rebuilt tissue. Consensus can be found on several parameters, such as strain frequency (1 Hz) or the use of rest periods, but other points have not yet been fully established, especially synergies with other solicitations. It is believed that the present work will be useful to develop new tissue‐engineering processes based on stretching.
N‐back training and transfer effects revealed by behavioral responses and EEG
Authors: Pergher Valentina , Wittevrongel Benjamin , Tournoy Jos , Schoenmakers Birgitte , Van Hulle Marc M.
Published: October 2018

Introduction

Cognitive function performance decreases in older individuals compared to young adults. To curb this decline, cognitive training is applied, but it is not clear whether it improves only the trained task or also other cognitive functions. To investigate this, we considered an N‐back working memory (WM) training task and verified whether it improves both trained WM and untrained cognitive functions.

Methods

As EEG studies have noted task difficulty and age‐related changes in time‐locked EEG responses, called event‐related potentials (ERPs), we focused on the relation between the P300 ERP component, task difficulty level, and behavior response accuracy and reaction time (RT) in young and older healthy adults. We used two groups of young and older healthy participants to assess the effect of N‐back training: cognitive training group (CTG) and passive control group (PCG). Before and after training, cognitive tests were administered to both groups to evaluate transfer effects.

Results

Despite the observed age‐related differences in the P300 ERP component and in terms of RT and accuracy, our findings demonstrate a stronger improvement in the trained task for older CTGs compared to younger CTGs, larger near‐ and far‐transfer effect to WM and fluid intelligence for both younger and older CTGs, and a far‐transfer effect to attention but only for older adults. Significant differences in response accuracy were shown between young and older subjects in spatial memory and attention tests.

Conclusion

The application of a WM training is a promising tool for both healthy adults, and in particular for older subjects, as it showed physiological and behavioral differences in cognitive plasticity across life span and evidence of benefits in the trained task and near‐/far‐transfer effects to other cognitive functions.
Enhanced Delivery of Synthetic Labelled Ubiquitin into Live Cells by Using Next‐Generation Ub–TAT Conjugates
Authors: Hameed Dharjath S. , Sapmaz Aysegul , Gjonaj Lorina , Merkx Remco , Ovaa Huib
Published: October 2018

Proteins and other macromolecules can be delivered into live cells by noninvasive techniques using cell‐penetrating peptides. These peptides are easily synthesised by solid‐phase peptide synthesis and can be conjugated onto cargo molecules to mediate cellular delivery. We designed a TAT‐based cell‐penetrating ubiquitin (Ub) reagent by conjugating a dimeric disulfide‐linked TAT peptide to the C terminus of a rhodamine‐labelled Ub (RhoUb) protein. This reagent efficiently enters the cell by endocytosis and escapes from endosomes into the cytoplasm. Once the conjugate is inside the cytoplasm, the delivery vehicle is proteolytically removed by endogenous deubiquitinases (DUBs), at which point the intrinsic ubiquitination machinery is able to incorporate the RhoUb into ubiquitin conjugates. Our approach enables the controlled delivery of labelled or mutant Ub derivatives into cells, increasing our options for studying the ubiquitin system.
In vitro flow and optical coherence tomography comparison of two bailout techniques after failed provisional stenting for bifurcation percutaneous coronary interventions
Authors: Adjedj Julien , Picard Fabien , Mogi Satoshi , Iwasaki Kiyotaka , Aoumeur Hamid , Alansari Omar , Agudze Edem , Wijns William , Varenne Olivier
Published: October 2018

Objectives

To evaluate, in vitro, SB stenting techniques after failed provisional stenting. We aimed to compare flows and stent strut apposition of T and protrusion (TAP) versus Reversed String (RS) techniques using a flow simulator, optical coherence tomography (OCT) using silicon bifurcation phantoms with different bifurcation angulations.

Background

While bifurcation coronary artery stenoses are preferably treated with provisional T‐stenting strategy, the preferred bailout two stents technique to treat the side branch remains unclear.

Methods and results

Eleven 30°‐angle and ten 60°‐angle bifurcation phantoms were used. After performing provisional stenting, TAP and RS techniques were compared in six phantoms with 30° and five with 60° angles. Flow measurement was performed using absolute coronary flow and particle image velocimetry techniques. Strut apposition was evaluated using OCT. Flow analyses showed that disturbed flow regions were observed in the vicinity of floating struts protruded into the lumen both regardless of TAP and RS techniques. OCT analysis showed a higher proportion of floating struts protruding into the main branch with TAP compared to RS, respectively (13% vs. 1%; P <0.001) in both angles.

Conclusions

RS reduces the proportion of floating struts protruding into the main branch compared to TAP, at comparable flow rates. Clinical studies are needed to evaluate feasibility and potential clinical benefit of this technique.
On the Geometrical Stability of Square‐Planar Platinum(0) Complexes That Bear a PNP‐Pincer‐Type Phosphaalkene Ligand (Eind2‐BPEP)
Authors: Taguchi Hiro‐omi , Tanigawa Ippei , Takeuchi Katsuhiko , Ozawa Fumiyuki
Published: October 2018

The four‐coordinate Pt0 complex [Pt(PPh3)(Eind2‐BPEP)] (Eind=1,1,3,3,5,5,7,7‐octaethyl‐1,2,3,5,6,7‐hexahydro‐s‐indacen‐4‐yl; BPEP=2,6‐bis(1‐phenyl‐2‐phosphaethenyl)pyridine), which bears a PNP‐pincer‐type phosphaalkene ligand (Eind2‐BPEP; PNP=N,N‐bis(diphenylphosphine)‐2,6‐diaminopyridine), were found to adopt a square‐planar configuration around the Pt center (τ4=0.11). This coordination geometry is very uncommon for formal d10 complexes. In this study, a series of ligands with different electronic properties (i.e., DMAP, 2,6‐lutidine, PMe3, tBuNC, and CO) were introduced in place of PPh3, and their effects on the coordination geometry were examined. X‐ray diffraction analysis revealed that all complexes adopted a square‐planar configuration (τ4=0.20–0.27). In contrast, DFT calculations indicated that the geometrical stability towards distortion around Pt varied with the ligand. The complexes with pyridine‐based ligands had rigid planar structures, whereas those with π‐accepting ligands, such as CO, were relatively flexible towards distortion. The electronic effects of the ligands were reflected in the spectroscopic properties of the complexes, which showed a large color change in the near‐infrared region.
Star‐Shaped and Fused Electron Acceptors based on C3h‐Symmetric Coplanar Trindeno[1, 2‐b: 4, 5‐b′: 7, 8‐b′′]trithiophene Core for Non‐Fullerene Solar Cells
Authors: Wang Weijie , Wu Xiaofu , Hang Hao , Li Hua , Chen Yonghong , Xu Qian , Tong Hui , Wang Lixiang
Published: October 2018

Two new star‐shaped and fused electron acceptors, TITT‐3IC and TITT‐3ICF have been designed and synthesized, which consist of a C3h‐symmetric coplanar trindeno[1, 2‐b: 4, 5‐b′: 7, 8‐b′′]trithiophene (TITT) as the central core and 3‐(dicyanomethylidene)indan‐1‐one and 2‐(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene) malononitrile as the peripheral electron‐withdrawing groups, respectively. With the large coplanar configuration and electron‐rich nature of π‐conjugated backbone, these two acceptors exhibit strong intermolecular charge transfer absorption in the region of 500–650 nm with the optical band gaps around 1.9 eV. Relative to TITT‐3IC, TITT‐3ICF shows the downshifted LUMO level and the slightly redshifted absorption with the higher molar extinction coefficient due to the stronger electron‐withdrawing effect of fluorination. When blending with PTB7‐Th, the TITT‐3ICF‐based device displays a higher power conversion efficiency (PCE) of 4.26 % than the TITT‐3IC‐based device (PCE=3.87 %). Comparing with the TITT‐3IC‐based device, the increased short circuit current (JSC) and fill factor (FF) are responsible for the higher PCE value of the TITT‐3ICF‐based device, which benefits from its strong and redshifted absorption for light harvesting and proper phase separation morphology for effective exciton dissociation and charge transport. This work demonstrates that as an alternative electron‐donating core, TITT will be promising in designing star‐shaped non‐fullerene materials.
Transcatheter aortic valve replacement in patients with pure native aortic valve regurgitation: A systematic review and meta‐analysis
Authors: Haddad Abdullah , Arwani Remy , Altayar Osama , Sawas Tarek , Murad M. Hassan , de Marchena Eduardo
Published: October 2018

This systematic review and meta‐analysis sought to summarize the available evidence on the use of transcatheter aortic valve replacement (TAVR) in patients with Native Aortic Valve Regurgitation (NAVR) and compare outcomes between first and second generation valves. Owing to the improvements in transcatheter heart valve design and procedural success, TAVR has become increasingly performed in broader aortic valve pathologies. We searched Medline, Embase, Cochrane, and Scopus databases from 2007 to 2018 and performed a systematic review on reports with at least 10 patients with aortic valve regurgitation undergoing TAVR procedure. The main outcome of interest was all‐cause mortality at 30 days. A total of 638 patients across 12 studies were included. Mean age ranged from 68 to 84. Society of Thoracic Surgeons score ranged from 5.4% to 13.1% and Logistic EuroSCORE ranged from 18.2% to 33%. The incidence rate of all‐cause mortality at 30 days was found to be 11% (95% CI 7%‐16%; I2 = 20.86%). All‐cause mortality at 30 days for first generation valves had an incidence rate of 15% (95% CI 10%‐20%; I2 = 10%) compared to 7% (95% CI 3%‐13%; I2 = 37%) in second generation valves with subgroup interaction analysis P = 0.059. Device success incidence rate in second generation valves was 92% (95% CI 83%‐99%; I2 = 67%) vs 68% (95% CI 59%‐77%; I2 = 53%) in first generation valves with P = 0.001. TAVR appears to be a feasible treatment choice for NAVR patients at high risk for surgical valve replacement. Second generation valves show promising results in terms of short‐term outcomes.
Strong effect of the simultaneous color contrast in an afterimage
Authors: Ikeda Mitsuo , Phuangsuwan Chanprapha
Published: October 2018

The color appearance of the afterimage of the simultaneous color contrast pattern was investigated by the elementary color naming method. The color appearances of the surrounding, an afterimage of the surrounding, and the test patch were measured, and the results were shown on the polar diagram of the opponent colors theory. The colors of both the surrounding and the afterimage of the test patch were the same. The relationship between the afterimage color of the test patch and the afterimage of the surrounding was found to be the same as the relationship between the illumination color and the test patch color in the two‐rooms technique, implying that the same visual mechanism works for both situations, that is, eyes chromatically adapt to the afterimage color of the surroundings, and the afterimage color of the test patch is determined with the eyes so adapted.
Brand purchase prediction based on time‐evolving user behaviors in e‐commerce
Authors: Dong Yunqi , Jiang Wenjun
Published: October 2018

Purchase prediction is a key function in the e‐commerce recommendation system. Existing works usually focus on item‐level purchase prediction, which faces two issues of high cost and low accuracy. In this paper, we study brand purchase prediction by exploring behaviors, which may lead to brand purchases. We make three progresses. (1) We analyze a real world e‐commerce data from multiple angles. Focusing on users' brand purchases, we find behaviors' evolution with time and behaviors' interaction. (2) For different behaviors, we extract different time‐evolving features that can serve as indicators of users' brand purchase. (3) We use a logistic regression‐based model by adjusting the parameters of time‐evolving feature and others in two different scenarios (the promotion purchase prediction and the daily purchase prediction) to construct two experiments. The experiment results show that the model using three types features performs the best in both scenarios, and the time‐evolving feature plays the most important role among them. (4) We distinguish the feature importance in different scenarios. Based on the importance, we find that users' purchases in the promotion scenario are likely to be impulsive, while purchases in the daily scenario are more likely to be influenced by users' activities.
Enhanced transductive support vector machine classification with grey wolf optimizer cuckoo search optimization for intrusion detection system
Authors: Roopa Devi E.M. , Suganthe R.C.
Published: October 2018

These days, the Intrusion detection System (IDS) is the most talked topic among the scientist and researchers and many research is going on in IDS, which is firmly connected to the protected utilization of system administrations. IDS are an essential part of the security infrastructure. The previous research works are focused to detect the attacks efficiently but it is failed to produce more accurate classification results. To stay away from the previously mentioned issues, in the proposed framework, Hybrid Grey Wolf optimizer Cuckoo Search Optimization (HGWCSO) along with Enhanced Transductive Support Vector Machine (ETSVM) is proposed. This exploration incorporates the modules are, for example, preprocessing, selection of features and classification of features. The processing of data is done by using normalization technique by using min‐max technique the main work is to replace the value missed and filters the features from NSL KDD dataset values. The main objective of processing of data is to increase the accuracy of classification. Then, the more relevant and optimal features are selected by using HGWCSO. The GWO robustness and searching performance is increased by cuckoo search algorithm. Then, the classification is performed to identify the intrusion attack types using ETSVM algorithm more efficiently. This classification algorithm is used to improve the attack detection accuracy higher. The experimental result concludes that the proposed HGWCSO with ETSVM algorithm provides better performance metrics in terms of high precision, sensitivity, specificity, and accuracy than the previous algorithms.
The Influence of the Amino Acid Side Chains on the Raman Optical Activity Spectra of Proteins
Authors: Mensch Carl , Johannessen Christian
Published: October 2018

The Raman optical activity (ROA) spectra of proteins show distinct patterns arising from the secondary structure. It is generally believed that the spectral contributions of the side‐chains largely cancel out because of their flexibility and the occurrence of many side‐chains with different conformations. Yet, the influence of the side‐chains on the ROA patterns assigned to different secondary structures is unknown. Here, the first systematic study of the influence of all amino acid side‐chains on the ROA patterns is presented based on density functional theory (DFT) calculations of an extensive collection of peptide models that include many different side‐chain and secondary structure conformations. It was shown that the contributions of the side‐chains to a large extent average out with conformational flexibility. However, specific side‐chain conformations can have significant contributions to the ROA patterns. It was also shown that α‐helical structure is very sensitive to both the exact backbone conformation and the side‐chain conformation. Side‐chains with χ1≈−60° generate ROA patterns alike those in experiment. Aromatic side‐chains strongly influence the amide III ROA patterns. Because of the huge structural sensitivity of ROA, the spectral patterns of proteins arise from extensive conformational averaging of both the backbone and the side‐chains. The averaging results in the fine spectral details and relative intensity differences observed in experimental spectra.
A Bean‐Like Formation of Germanium Nanoparticles Inside CNTs by the Subsequent Operation of Colloidal Synthesis and Catalytic Chemical Vapor Deposition Methods
Authors: Karatutlu Ali , Boi Filippo S. , Wilson Rory M. , Ersoy Osman , Ortac Bulend , Sapelkin Andrei
Published: October 2018

The first attempts of implanting Ge nanoparticles (Ge NPs) inside iron filled CNTs (IF‐CNTs) by a subsequent use of the bench top colloidal synthesis and chemical vapor deposition (CVD) approach is shown. Ge NPs are colloidally synthesized (with a 3.8 ± 0.6 nm in size) before the deposition. The hybrid Ge NPs/IF‐CNTs structure and morphology are characterized using high‐resolution transmission electron microscopy, scanning electron microscopy, selective area electron diffraction, and X‐ray diffraction studies. After the deposition, Ge NPs appear to be grown in size and to be sprinkled almost homogeneously into the IF‐CNTs similar to a bean‐like deposition. CNTs diameter is also identified to be enlarged drastically when using Ge NPs as a catalyst in CVD compared to the CNTs formation without Ge NPs. In addition, micro‐length rectangular Ge µPs are also found outside the nanotube core. Rietveld analysis shows the presence of γ‐Fe (Fm‐3m), ferromagnetic α‐Fe (Im‐3m), Fe3C, Ge (Fd‐3m), and multiwall CNTs. The results indicate that Ge NPs and IF‐CNTs demonstrate cocatalytic activity in increasing the respective sizes, which are dramatically larger than those obtained by the conventional approaches.
ILC‐poiesis: Ensuring tissue ILC differentiation at the right place and time
Authors: Lim Ai Ing , Di Santo James P.
Published: October 2018

Innate lymphoid cells (ILCs) represent a family of innate effector cells including NK cells, lymphoid tissue inducer (LTi) cells, and distinct ILC1, ILC2, and ILC3 subsets that produce IFN‐γ, IL‐5/IL‐13, and IL‐17A/IL‐22, respectively. ILCs accumulate at mucosal sites and can promote the first‐line defense against infection. ILCs are also implicated in tissue repair and can either pre‐empt, or alternatively, exacerbate inflammation. Studies in mice have identified ILC precursors in fetal liver and adult BM that have diverse lineage potential. As such, these sites have been considered as the ‘factories’ to generate mature ILC. Here, we summarize knowledge concerning murine and human ILC development and discuss the recent identification of circulating multipotent and unipotent ILC precursors. We propose an alternative model of “ILC‐poiesis”, whereby blood ILC precursors migrate into tissues to complete their differentiation into mature ILC subsets under the influence of local environmental factors. Within this framework, ILC‐poiesis guarantees appropriate ILC generation at the right place and the right time. We further discusss the potential applications of circulating ILC precursors for cell therapy of human disease.
Polymer‐Shell‐Encapsulated Magnetite Nanoparticles Bearing Hexamethylenetetramine for Catalysing Aza‐Michael Addition Reactions
Authors: Rathod Prakash B. , Kumar K. S. Ajish , Athawale Anjali A. , Pandey Ashok K. , Chattopadhyay Subrata
Published: October 2018

Polymer‐encapsulated magnetite nanoparticles bearing Hexamethylenetetramine (Fe3O4@HMTA) have been developed for catalysing the aza‐Michael addition to form β‐amino compounds. The effects of solvent, amount and reuse on catalytic activity of the Fe3O4@HMTA have been studied. The catalytic activity of the Fe3O4@HMTA has not deteriorated during successive recycling. Eight different substrates have been subjected to aza‐Michael additions, and yields of the products in the range of 50–90 % have been observed in the presence of catalyst depending upon the substituent groups in the reactants. The formation of a single chiral adduct by reacting a acrylamide derivative of l‐proline benzyl ester with morpholine seems to suggest that the reaction conditions preclude the racemization of products.
Direct Synthesis of Indanes via Iron‐Catalyzed Dehydrative Coupling/Friedel–Crafts Cyclization of Two Different Alcohols
Authors: Sai Masahiro
Published: October 2018

We report herein a novel iron‐catalyzed cascade dehydrative coupling/Friedel–Crafts cyclization of two different alcohols, providing a variety of indanes, which are ubiquitous substructures found in natural products, pharmaceuticals, and functional materials. Importantly, the developed approach is highly atom‐economic and environmentally benign, as it employs readily available alcohols as substrates and generates water as the only byproduct.
Simulation and experiment of asymmetric electrode placement for electrophoretic exclusion in a microdevice
Authors: Zhu Fanyi , Hayes Mark A.
Published: October 2018

Electrophoretic exclusion (EE) is a counterflow gradient technique that exploits hydrodynamic flow and electrophoretic forces to exclude, enrich, and separate analytes. Resolution for this technique has been theoretically examined and the smallest difference in electrophoretic mobilities that can be completely separated is estimated to be 10−13 cm2/Vs. Traditional and mesoscale systems have been used, whereas microfluidics offers a greater range of geometries and configurations towards approaching this theoretical limit. To begin to understand the impact of seemingly subtle changes to the entrance flow and the electric field configurations, three closely related microfluidic interfaces were modeled, fabricated, and tested. These interfaces consisted of systematically varying placement of an asymmetric electrode relative to a channel entrance: leading electrode placed outside the channel entrance, leading electrode aligned with the channel, and leading electrode placed within the channel. A charged fluorescent dye is used as a sensitive and accurate probe for the model and to test the concentration variation at these interfaces. Models and experiments focused on visualizing the concentration profile in areas of high temporal dynamics, thus providing a severe test of the models. Experimental data and simulation results showed strong qualitative agreement. The complexity of the electric and flow fields about this interface and the agreement between models and testing suggests the theoretical assessment capabilities can be used to faithfully design novel and more efficient interfaces.
A cell electro‐rotation micro‐device using polarized cells as electrodes
Authors: Huang Liang , He Weihua , Wang Wenhui
Published: October 2018

Cell rotation is widely required in various fields as an important technique for single cell manipulation. Usually, the electro‐rotational manipulation of single cells by dielectrophoresis technologies requires at least three electrodes to generate rotating electric fields which induce cells to rotate. Here, we present a novel microfluidic chip capable of rotating single cell using only two planar electrodes by taking polarized cells as the extra electrodes with phase‐shifted signal. To demonstrate this idea, we configured two parallel and planar electrodes as basic dielectrophoresis elements and placed trenches above these electrodes to attract cells, which were in turn polarized to be electrodes. Through simulation, we confirmed the functional structure of the device works well to generate proper rotating electric fields for cell rotation. Through experiment, we successfully demonstrated controlled electro‐rotation of HeLa and HepaRG cells. The novel electro‐rotation mechanism not only simplifies the micro‐device structure but also reduces the complexity of single cell rotation operation which will be a benefit to the potential users.
Versatile provisioning and workflow scheduling in WaaS under cost and deadline constraints for cloud computing
Authors: Partheeban Pon. , Kavitha V.
Published: October 2018

Cloud computing environment delivers resources and services via a pay‐as‐you‐go billing model, and scheduling workflows have become a major application for distributed systems. An efficient scheduling is very challenging in a cloud to achieve minimum overhead, low cost, and high utilization of resources within the deadline. Workflow as a service (WaaS) provides a simple cost successive way to use the workflow applications in the cloud. This paper introduces a Gang of Tasks (GoTs)–based dynamic scheduling technique for scheduling the workflow to reduce the cost of renting virtual machines (VMs) under the deadline constraints in the WaaS environment. First, the GoTs strategy groups the workflows based on the priority and dependency of data. It schedules similar tasks into the same gang to execute the task from the gang simultaneously to the VMs. After scheduling the task in the GoTs, the deadline is distributed among all the gangs in the workflow. Then, the versatile resources are provisioned, dynamically depending upon the usage of containers in the VMs. The simulation results validate the ability to satisfy the deadline constraints and cost deficiencies of the proposed method as compared to the state‐of‐the‐art methods.
Outsourced revocable identity‐based encryption from lattices
Authors: Dong Chengcheng , Yang Kang , Qiu Jian , Chen Yuanfang
Published: October 2018

With the popularization of mobile devices, the security of wireless industrial communication technology is becoming more and more important to the information exchange of industrial production. Identity‐based encryption (IBE) is an essential branch of public key encryption, which simplifies the management of public key infrastructure. However, if these IBE cryptosystems need to revoke users, the computational overheads of the private key generator (PKG) will be substantial. In this work, in order to solve the critical issue related to revocation, we are the first to introduce outsourcing computation into lattice‐based revocable IBE (RIBE) and propose a outsourced revocable lattice‐based IBE (OR‐LIBE) scheme. In our model, most of PKG's offloads are delegated to a semitrusted cloud service provider (CSP). The scheme divides the private key into an identity component and a time component, which are generated by PKG and key update CSP (called KU‐CSP), respectively, but PKG must distribute a corresponding identity outsourcing key OKid to KU‐CSP. Our scheme is more efficient for user revocation than the previous lattice‐based RIBE schemes. Compared with the classic RIBE scheme, our scheme is resistant against quantum attacks. The proposed scheme is adaptively secure under the standard model, and its security can be reduced to hardness of learning with errors assumption. Our scheme can be applied to wireless industrial communication technology to improve the security of communication data.