bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlled synthesis of 3D porous VO2(B) hierarchical spheres with different interiors for energy storage
Authors: Zhang Yifu , Jing Xuyang , Cheng Yan , Hu Tao , Changgong Meng
Published: September 2018

3D VO2(B) hollow spheres exhibit better electrochemical properties, including specific capacitance, areal energy density and cycling stability, than VO2(B) solid spheres.
Engineering two-dimensional layered nanomaterials for wearable biomedical sensors and power devices
Authors: Cao Xianyi , Halder Arnab , Tang Yingying , Hou Chengyi , Wang Hongzhi , Duus Jens Øllgaard , Chi Qijin
Published: September 2018

Recent progress on two-dimensional layered nanomaterials supported wearable biomedical sensors and power devices is comprehensively reviewed.
One-pot transition-metal free transamidation to sterically hindered amides
Authors: Guo Weijie , Huang Jingjun , Wu Hongxiang , Liu Tingting , Luo Zhongfeng , Jian Junsheng , Zeng Zhuo
Published: September 2018

A highly efficient one-pot transamidation of primary amides has been developed under transition-metal free conditions, generating a variety of amides including hindered amides in good yield (up to 86%) catalyzed by CsF.
In-line separation of multicomponent reaction mixtures using a new semi-continuous supercritical fluid chromatography system
Authors: Fitzpatrick Daniel E. , Mutton Robbie J. , Ley Steven V.
Published: September 2018

A new bespoke semi-continuous parallel column supercritical fluid chromatography unit has been developed that solves the problem of effective separation of continuous, multicomponent reaction mixtures.
Machine learning material properties from the periodic table using convolutional neural networks
Authors: Zheng Xiaolong , Zheng Peng , Zhang Rui-Zhi
Published: September 2018

Convolutional neural networks directly learned chemical information from the periodic table to predict the enthalpy of formation and compound stability.
Insight into wild-type and T1372E TET2-mediated 5hmC oxidation using ab initio QM/MM calculations
Authors: Torabifard Hedieh , Cisneros G. Andrés
Published: September 2018

T1372E TET2 stalls at 5hmC due to unfavorable orientation of substrate, which increases barrier of the rate limiting step.
Advanced microRNA-based cancer diagnostics using amplified time-gated FRET
Authors: Qiu Xue , Xu Jingyue , Guo Jiajia , Yahia-Ammar Akram , Kapetanakis Nikiforos-Ioannis , Duroux-Richard Isabelle , Unterluggauer Julia J. , Golob-Schwarzl Nicole , Regeard Christophe , Uzan Catherine , Gouy Sébastien , DuBow Michael , Haybaeck Johannes , Apparailly Florence , Busson Pierre , Hildebrandt Niko
Published: September 2018

FRET and rolling circle amplification outperform RT-qPCR for microRNA diagnostics in clinical samples.
An evolutionary algorithm for the discovery of porous organic cages
Authors: Berardo Enrico , Turcani Lukas , Miklitz Marcin , Jelfs Kim E.
Published: September 2018

An evolutionary algorithm is developed and used to search for shape persistent porous organic cages.
Push–pull architecture eliminates chain length effects on exciton dissociation
Authors: Aplan Melissa P. , Lee Youngmin , Wilkie Carly A. , Wang Qing , Gomez Enrique D.
Published: September 2018

Push–pull architecture decreases the required conjugation length to achieve efficient charge transfer and enables single-site exciton dissociation.
Ligand-mediated bifunctional catalysis for enhanced oxygen reduction and methanol oxidation tolerance in fuel cells
Authors: Lu Linfang , Wang Zhiqiang , Zou Shihui , Zhou Yuheng , Hong Wei , Li Renhong , Xiao Liping , Liu Juanjuan , Gong Xue-Qing , Fan Jie
Published: September 2018

By controllably tuning the surface coverage of pyridine on Pt nanoparticles, we successfully achieve bifunctional catalysis in direct methanol fuel cells.
Significantly improved performance of dye-sensitized solar cells by optimizing organic dyes with pyrrole as the isolation spacer and utilizing alkyl chain engineering
Authors: Wang Jinfeng , Liu Siwei , Chai Zhaofei , Chang Kai , Fang Manman , Han Mengmeng , Wang Yiyi , Li Sheng , Han Hongwei , Li Qianqian , Li Zhen
Published: September 2018

The conversion efficiencies of dye sensitized solar cells were largely enhanced by the optimization of intramolecular and interfacial charge transfer.
Decorating β′′-alumina solid-state electrolytes with micron Pb spherical particles for improving Na wettability at lower temperatures
Authors: Chang Hee-Jung , Lu Xiaochuan , Bonnett Jeffery F. , Canfield Nathan L. , Han Keesung , Engelhard Mark H. , Jung Keeyoung , Sprenkle Vincent L. , Li Guosheng
Published: September 2018

Na wetting in a sunny-side-up shape is observed on a β′′-alumina surface decorated with micron-sized lead spherical particles.
Construction of a low-defect and highly conductive 3D graphene network to enable a high sulphur content cathode for high performance Li–S/graphene batteries
Authors: Zhang Shijie , Xiao Weidong , Zhang Yongshang , Liu Kangli , Zhang Xiangdan , Zhao Jiangtao , Wang Zhuo , Zhang Peng , Shao Guosheng
Published: September 2018

A low-defect and highly conductive 3D graphene network to enable a high sulfur content cathode for high performance Li–S batteries.
Towards high areal capacitance, rate capability, and tailorable supercapacitors: Co3O4@polypyrrole core–shell nanorod bundle array electrodes
Authors: Ma Longtao , Fan Huiqing , Wei Xinying , Chen Shengmei , Hu Qingzhao , Liu Yan , Zhi Chunyi , Lu Wei , Zapien Juan Antonio , Huang Haitao
Published: September 2018

We report high-performance, flexible, and tailorable solid-state supercapacitors enabled by Co3O4@PPy nanorod bundle arrays immobilized on carbon fiber cloth (CFC).
Directional freeze-cast hybrid-backbone meso-macroporous bodies as micromonolith catalysts for gas-to-liquid processes
Authors: Kim Jonglack , Nese Valentina , Joos Jochen , Jeske Kai , Duyckaerts Nicolas , Pfänder Norbert , Prieto Gonzalo
Published: September 2018

Directional freeze casting enables the assembly of bimodally porous micronomolith Fischer–Tropsch catalyst bodies with enhanced effective thermal conductivity and pore molecular transport rates, leading to a high selectivity to liquid olefin products.
A facile annealing strategy for achieving in situ controllable Cu2O nanoparticle decorated copper foil as a current collector for stable lithium metal anodes
Authors: Zhang Qi , Luan Jingyi , Tang Yougen , Ji Xiaobo , Wang Shuangyin , Wang Haiyan
Published: September 2018

Lithiophilic Cu2O nanoparticle decorated copper foil synthesized by a facile air annealing approach was employed as a lithium plating substrate.
A single fluorescent probe for imaging ribonucleic acid and sulfur dioxide in living systems and its unique application in tumor and normal cells
Authors: Wang Weishan , Liu Yong , Niu Jie , Lin Weiying
Published: September 2018

Herein, the development of EPI-RS is described as the first paradigm of a probe that could image RNA and SO2 with distinct fluorescence signals in living systems.
Organic phototransistors based on perylene diimide nanocrystals lacking π–π interactions
Authors: Bronshtein Ilya , Iron Mark A. , Rybtchinski Boris
Published: September 2018

We show that the organic crystals lacking π-overlap mediate photocurrent, dependent on optical power, which is due to imide/π-core noncovalent interactions.
Novel two-component gels with multi-stimuli response: the gel–sol phase transition and color changes
Authors: Fan Kaiqi , Wang Xiaobo , Yin Zhigang , Jia Caijing , Zhang Baohao , Zhou Liming , Song Jian
Published: September 2018

A smart two-component gelator system was prepared by a combination of d-gluconic acetal derivatives and terpyridyl moieties.
A simple D–π–A hybrid mode for highly efficient non-doped true blue OLEDs with CIEy < 0.05 and EQE up to 6%
Authors: Shi Jinjin , Ding Qi , Xu Lei , Lv Xianhao , Liu Zhongwei , Sun Qikun , Pan Yuyu , Xue Shanfeng , Yang Wenjun
Published: September 2018

A new true blue fluorescent emitter (TPATZ) is designed and facilely synthesized. The non-doped device exhibits true blue EL with CIE coordinates of (0.155, 0.047), and the y value is fairly small and superior to the EBU standard of 0.06 and an impressive maximum EQE up to 5.92%.
Novel and classical renal biomarkers as evidence for the nephroprotective effect ofCarica papayaleaf extract
Authors: Gheith Ibtsam , El-Mahmoudy Abubakr
Published: September 2018

The present study is aimed at utilization of novel and classical kidney function biomarkers to evaluate the nephroprotective potential of Carica papaya leaf extract (CPLE) in gentamicin nephrotoxicity model in albino rats. The used classical biomarkers were urea and creatinine; while the new biomarkers were Kidney injury molecule-1 (KIM-1) and Clusterin. Forty-five male albino rats were assigned into five groups and subjected to different treatments for nine consecutive days (vehicles; gentamicin, 100 mg/kg, subcutaneously; ascorbic acid, 200 mg/kg, orally; CPLE, 150 and 300 mg/kg b wt., orally). Three rats/group were killed on days 3, 6, and 9 for blood and tissue samples for renal and oxidation markers. Gentamicin resulted in significant increase in urea and creatinine only by the end of the experimental course; while the novel biomarkers were evident as early as 3 days upon gentamicin injection. When concurrently administered with gentamicin, CPLE significantly protected kidney tissues against gentamicin nephrotoxic effects indicated by decrement of both the novel and the classical standard biomarkers, in a dose-dependent manner. CPLE-mediated protection was attributed to its antioxidant potential indicated by significant inhibition of malondialdehyde (MDA) levels in both serum and kidney homogenates. The results were further supported by histopathological examination that revealed considerable amelioration of the pathological microscopic alterations induced by repeated gentamicin injection. Phytochemical analysis of CPLE indicated presence of tannins and flavonoids. These data may suggest CPLE, based on improvement of both classical and novel renal markers, as a highly potent nephroprotective and antioxidant from natural source that could be a good remedy in conditions associated with renal disorders.
The archaeal RecJ-like proteins: nucleases and ex-nucleases with diverse roles in replication and repair
Authors: MacNeill Stuart A.
Published: September 2018

RecJ proteins belong to the DHH superfamily of phosphoesterases that has members in all three domains of life. In bacteria, the archetypal RecJ is a 5′ → 3′ ssDNA exonuclease that functions in homologous recombination, base excision repair and mismatch repair, while in eukaryotes, the RecJ-like protein Cdc45 (which has lost its nuclease activity) is a key component of the CMG (Cdc45–MCM–GINS) complex, the replicative DNA helicase that unwinds double-stranded DNA at the replication fork. In archaea, database searching identifies genes encoding one or more RecJ family proteins in almost all sequenced genomes. Biochemical analysis has confirmed that some but not all of these proteins are components of archaeal CMG complexes and has revealed a surprising diversity in mode of action and substrate preference. In addition to this, some archaea encode catalytically inactive RecJ-like proteins, and others a mix of active and inactive proteins, with the inactive proteins being confined to structural roles only. Here, I summarise current knowledge of the structure and function of the archaeal RecJ-like proteins, focusing on similarities and differences between proteins from different archaeal species, between proteins within species and between the archaeal proteins and their bacterial and eukaryotic relatives. Models for RecJ-like function are described and key areas for further study highlighted.
Method based on bitonic filtering decomposition and sparse representation for fusion of infrared and visible images
Authors: Xing Changda , Wang Zhisheng , Ouyang Quan , Dong Chong
Published: September 2018

Infrared and visible images fusion based on edge‐preserving can improve the fused result in a clear outline. However, there exists the performance degradation caused by some edges in the data which are smaller than the level of the noise with traditional edge‐preserving decomposition. To remedy such deficiency, a method based on bitonic filtering decomposition and sparse representation is proposed for fusion of infrared and visible images. The bitonic filtering decomposition and sparse representation (BFSR) method consists of three steps: multi‐scale bitonic filtering decomposition, mergence of base layers and detail layers, and reconstruction of the fused result. Compared with traditional image fusion based on edge‐preserving, data‐level‐sensitive parameters are not included in the BFSR method, which can locally adapt to the signal and noise levels in an image. Moreover, the sparsity of images for fusing details is used in the BFSR method, which can analyse the explanatory factors hidden behind the data. As demonstrated in the experimental results, the proposed BFSR method achieves much fusion performance compared with other commonly used image fusion methods.
Roadside unit location for information propagation promotion on two parallel roadways with a general headway distribution
Authors: Liang Yunyi , Wu Zhizhou , Tian Yu , Chen Huimiao
Published: September 2018

In this study, an analytical model for roadside unit (RSU) location is proposed. The objective of the model is to promote information propagation on two parallel roadways in vehicular ad hoc networks. The information propagation is achieved through multi‐hop vehicle‐to‐vehicle and vehicle‐to‐infrastructure communication. The relationship between the information travel time from one RSU to another and the distance between the two RSUs are derived. The RSU location problem is formulated as a shortest path problem and then as an integer linear programming. The proposed model is applicable for traffic flow with a general vehicle headway distribution. A detailed comparison between the proposed model and an existing RSU location model is conducted through Monto Carlo simulation experiments under different vehicle headway distributions, traffic densities, budget sizes, and road separation distances. The results indicate that the proposed model outperforms the existing model in all cases. Moreover, it is shown that it is necessary to consider the general vehicle headway distribution and road separation in RSU locations that are focused on information propagation promotion.
High efficient linear polariser using FSS structure
Authors: Samadi Fereshteh , Akbari Mohammad , Zarbakhsh Saman , Chaharmir Reza , Sebak Abdelrazik
Published: September 2018

A linear polarisation converter surface with broadband and high‐efficiency properties is proposed. The proposed frequency selective surface (FSS) polariser consists of two‐corner‐cut diagonal rectangular printed on a substrate backed by a pinwheel loop shape ground. The combination of two‐corner‐cut diagonal rectangular patch and pinwheel loop shape ground contributes to bandwidth expansion. Numerical results indicate that the FSS structure is capable of converting x or y polarised incident wave to the relevant cross‐polarised wave in a wide frequency range from 7.5 to 24.5 GHz with a fractional bandwidth of 106% for −10 dB reflection amplitude. In addition, the and reflection coefficients of the proposed unit‐cell present slight variation for different incident angles up to 40°, which verifies the applicability of the proposed FSS structure in a practical environment. For experimental validation, a prototype of the FSS structure is fabricated and reflection parameters of the proposed structure are measured which agree well with corresponding simulations. Due to the minimal dependency on the angle of incidence and non‐uniform ground plane the proposed polarisation converter unit‐cell can be a possible choice for secure building applications.
The MEMO project: Combining all microlensing surveys to search for intermediate-mass Galactic black holes
Authors: Mirhosseini A. , Moniez M.
Published: September 2018

Aims. The microlensing surveys MACHO, EROS, MOA and OGLE (hereafter called MEMO) have searched for microlensing toward the Large Magellanic Cloud for a cumulated duration of 27 years. We study the potential of joining these databases to search for very massive objects, that produce microlensing events with a duration of several years.

Methods. We identified the overlaps between the different catalogs and compiled their time coverage to identify common regions where a joint microlensing detection algorithm can operate. We extrapolated a conservative global microlensing detection efficiency based on simple hypotheses, and estimated detection rates for multi-year duration events.

Results. Compared with the individual survey searches, we show that a combined search for long timescale microlensing should detect about ten more events caused by 100 M⊙ black holes if these objects have a major contribution to the Milky Way halo.

Conclusions. Assuming that a common analysis is feasible, meaning that the difficulties that arise from using different passbands can be overcome, we show that the sensitivity of such an analysis might enable us to quantify the Galactic black hole component.
Digitization and astrometric calibration of Carte du Ciel photographic plates with Gaia DR1
Authors: Lehtinen K. , Prusti T. , de Bruijne J. , Lammers U. , Manara C. F. , Ness J.-U. , Siddiqui H. , Markkanen T. , Poutanen M. , Muinonen K.
Published: September 2018

Context. Carte du Ciel was a global international project at the end of the nineteenth and beginning of the twentieth century to map the sky to about magnitude 14 on photographic plates. The full project was never observationally completed and a large fraction of the observations made remain unanalyzed.

Aims. We want to study whether the astrometric and photometric accuracies obtained for the Carte du Ciel plates digitized with a commercial digital camera are high enough for scientific exploitation of the plates.

Methods. We use a digital camera Canon EOS 5Ds, with a 100 mm macrolens for digitizing. We analyze six single-exposure plates and four triple-exposure plates from the Helsinki zone of Carte du Ciel (+39∘ ≤ δ ≤ +47∘). Each plate is digitized using four images, with a significant central area being covered twice for quality control purposes. The astrometric calibration of the digitized images is done with the data from the Tycho-Gaia Astrometric Solution (Gaia TGAS) of the first Gaia data release (Gaia DR1), Tycho-2, Hot Stuff for One Year (HSOY), USNO CCD Astrograph Catalog (UCAC5), and PMA catalogs.

Results. The best astrometric accuracy is obtained with the UCAC5 reference stars. The astrometric accuracy for single-exposure plates is σ(α cos(δ)) = 0.16″ and σ(δ)=0.15″, expressed as a Gaussian deviation of the astrometric residuals. For triple-exposure plates the astrometric accuracy is σ(α cos(δ)) = 0.12″ and σ(δ)=0.13″. The 1 − σ uncertainty of photometric calibration is about 0.28 mag and 0.24 mag for single- and triple-exposure plates, respectively. We detect the photographic adjacency (Kostinsky) effect in the triple-exposure plates.

Conclusions. We show that accuracies at least of the level of scanning machines can be achieved with a digital camera, without any corrections for possible distortions caused by our instrumental setup. This method can be used to rapidly and inexpensively digitize and calibrate old photographic plates enabling their scientific exploitation.
Impact of galactic shear and stellar feedback on star formation
Authors: Colling Cédric , Hennebelle Patrick , Geen Sam , Iffrig Olivier , Bournaud Frédéric
Published: September 2018

Context. Feedback processes and the galactic shear regulate star formation.

Aims. We investigate the effects of differential galactic rotation and stellar feedback on the interstellar medium (ISM) and on the star formation rate (SFR).

Methods. A numerical shearing box is used to perform three-dimensional simulations of a 1 kpc stratified cubic box of turbulent and self-gravitating interstellar medium (in a rotating frame) with supernovae and H II feedback. We vary the value of the velocity gradient induced by the shear and the initial value of the galactic magnetic field. Finally, the different star formation rates and the properties of the structures associated with this set of simulations are computed.

Results. We first confirm that the feedback has a strong limiting effect on star formation. The galactic shear has also a great influence: the higher the shear, the lower the SFR. Taking the value of the velocity gradient in the solar neighbourhood, the SFR is too high compared to the observed Kennicutt law, by a factor approximately three to six. This discrepancy can be solved by arguing that the relevant value of the shear is not the one in the solar neighbourhood, and that in reality the star formation efficiency within clusters is not 100%. Taking into account the fact that star-forming clouds generally lie in spiral arms where the shear can be substantially higher (as probed by galaxy-scale simulations), the SFR is now close to the observed one. Different numerical recipes have been tested for the sink particles, giving a numerical incertitude of a factor of about two on the SFR. Finally, we have also estimated the velocity dispersions in our dense clouds and found that they lie below the observed Larson law by a factor of about two.

Conclusions. In our simulations, magnetic field, shear, H II regions, and supernovae all contribute significantly to reduce the SFR. In this numerical setup with feedback from supernovae and H II regions and a relevant value of galactic shear, the SFRs are compatible with those observed, with a numerical incertitude factor of about two.
Stability of error bounds for conic subsmooth inequalities
Authors: Zheng Xi Yin , Ng Kung-Fu
Published: September 2018

Under either linearity or convexity assumption, several authors have studied the stability of error bounds for inequality systems when the concerned data undergo small perturbations. In this paper, we consider the corresponding issue for a more general conic inequality (most of the constraint systems in optimization can be described by an inequality of this type). In terms of coderivatives for vector-valued functions, we study perturbation analysis of error bounds for conic inequalities in the subsmooth setting. The main results of this paper are new even in the convex/smooth case.
Periodical metal cylinders for improving heating uniformity of small batch materials in microwave applicators with rotating turntables
Authors: Tao Mengling , Yang Fuxian , Tang Zhengming , He Jianbo , Liao Yinhong
Published: September 2018

Microwave applicators with rotating turntables have been widely applied in many fields, but the heating non-uniformity still limits the further applications. Specifically, when microwave applicators are used to process small batch materials, materials have to be away from the center of rotating turntables, where the problem of heating non-uniformity is more prominent. In order to overcome this difficulty, this paper presents a novel periodical metal cylinder structure to improve the heating uniformity for microwave applicators. With the proposed periodical metal cylinders being placed beneath rotating turntables, electromagnetic fields can be well adjusted, thus improving the heating uniformity. To demonstrate the heating uniformity with the proposed structure, the heating process of the arrays of two and three potato slices in a practical microwave applicator is simulated by the finite element method, respectively. The results show that both the heating uniformity of the two and three potato slices can be improved, which is validated by experiments. Furthermore, the results show that the temperature similarity among the processed potato slices with the proposed structure is better than that without the proposed structure.
Mesh stiffness modeling considering actual tooth profile geometry for a spur gear pair
Authors: Yang Yong , Wang Jiaxu , Zhou Qinghua , Huang Yanyan , Zhu Jinxuan , Yang Wanyou
Published: September 2018

Some tooth profile geometric features, such as root fillet area, flank modification and wear are of nonnegligible importance for gear mesh stiffness. However, due to complexity of analytical description, their influence on mesh stiffness was always ignored by existing research works. The present work derives analytical formulations for time-varying gear mesh stiffness by using parametric equations of flank profile. Tooth geometry formulas based upon a rack-type tool are derived following Litvin's vector approach. The root fillet area and tooth profile deviations can therefore be fully considered for spur gear tooth stiffness evaluation. The influence of gear fillet determined by tip fillet radius of the rack-type tool is quantified parametrically. The proposed model is validated to be effective by comparing with a finite element model. Further, the model is applied to investigate the stiffness variations produced by tooth addendum modification, tooth profile nonuniform wear and modification.
A cubic chromosome representation for patient scheduling in the Emergency Department
Authors: Ben Othman Sarah , Ajmi Faten , Zgaya Hayfa , Hammadi Slim
Published: September 2018

In healthcare institution management, hospital flow control and the prediction of overcrowding are major issues. The objective of the present study is to develop a dynamic scheduling protocol that minimizes interference between scheduled and unscheduled patients arriving at the emergency department (ED) while taking account of disturbances that occur in the ED on a daily basis. The ultimate goal is to improve the quality of care and reduce waiting times via a two-phase scheduling approach. In the first phase, we used a genetic algorithm (based on a three-dimensional cubic chromosome) to manage scheduled patients. In the second phase, we took account of the dynamic, uncertain nature of the ED environment (the arrival of unscheduled patients) by continuously updating the schedule.
Nanotechnological Approach to Increase the Antioxidant and Cytotoxic Efficacy of Crocin and Crocetin
Authors: Puglia Carmelo , Santonocito Debora , Musumeci Teresa , Cardile Venera , Graziano Adriana , Salerno Loredana , Raciti Giuseppina , Crascì Lucia , Panico Anna , Puglisi Giovanni
Published: September 2018

Crocin and crocetin are two interesting constituents of saffron (Crocus sativus) that possess important biological activities. Their use as therapeutic agents is strongly compromised by a scarce stability, poor absorption, and low bioavailability. Therefore, to improve these unfavorable features, the aim of the present work has been to apply a nanotechnological approach based on the formulation of solid lipid nanoparticles containing crocin and crocetin. Solid lipid nanoparticles were formulated according to crocin and crocetin chemical properties, using a variation of the quasi-emulsion solvent diffusion method to formulate crocin-solid lipid nanoparticles, while crocetin-solid lipid nanoparticles were prepared following the solvent diffusion method. Morphology and dimensional distribution of solid lipid nanoparticles have been characterized by differential scanning calorimetry and photon correlation spectroscopy, respectively, while the effect of drug incorporation versus time has been studied by Turbiscan technology. In order to verify the role of the nanotechnological approach on the biological activities of crocin and crocetin, the antioxidant and antiproliferative effects of these carotenoids once incorporated in lipid nanoparticles have been evaluated. For this aim, the oxygen radical absorbance capacity assay and the MTT test were used, respectively.

The results pointed out the formulation of nanometric dispersions endowed with high homogeneity and stability, with an encapsulation efficiency ranging from 80 (crocetin-solid lipid nanoparticles) to 94% (crocin-crocetin). The oxygen radical absorbance capacity assay evidenced an interesting and prolonged antioxidant activity of crocin and crocetin once encapsulated in solid lipid nanoparticles, while the nanoencapsulation strategy showed a different mechanism in ameliorating the cytotoxic effect of these two substances.
Novel and Convenient Synthesis of 2,7-Dialkyl-1,8-dihydro-as-indacenes­
Authors: Morales-Verdejo Cesar , Chávez Ivonne , Faúndez Rodrigo , Castillo Francisco , Preite Marcelo , Schott Eduardo , Zarate Ximena , Manriquez Juan , Molins Elies
Published: September 2018

A novel and convenient synthetic route towards dialkyl as-indacenes was achieved by alkylation of malonic esters with o-xylylene dibromide, to give the corresponding tetraester, and related diacid. The alkyl groups on the central benzene ring induce intramolecular, regiospecific cycloeliminations leading selectively to the diketones, the precursors of the corresponding 1,8-dihydro-as-indacenes. The structure of the 2,7-dimethyl-1,8-dihydro-as-indacene was determined by X-ray diffraction. The compound 2,7-diethyl-1,8-dihydro-as-indacene was characterized by means of 1H NMR, 13C NMR, FT-IR, UV/Vis measurements, electrochemistry, and elemental analysis. On the other hand, quantum chemical computations based on DFT methods were carried out to get insight into the molecular and electronic structures of the studied ligands. TDDFT approach was employed to calculate the vertical excitations and characterize the nature the UV/Vis absorption bands present in the experiments showing a very good agreement between experimental and calculated values. Finally, the reactivity of the compounds was assessed using the chemical potential (μ), chemical hardness (η), and electrophilicity (ω). Also, the electron-donating (ω–), electron-accepting (ω+), and the net electrophilicity powers (ω±) indexes were studied.
Peroneus Longus Tendon Autograft is a Safe and Effective Alternative for Anterior Cruciate Ligament Reconstruction
Authors: Shi Fu-Dong , Hess Daniel Edward , Zuo Jin-Zeng , Liu Shi-Jie , Wang Xue-Chen , Zhang Yong , Meng Xiao-Guang , Cui Ze-Jun , Zhao Shao-Ping , Li Chang-Jiang , Hu Wan-Ning
Published: September 2018

The ipsilateral peroneus longus tendon (PLT) was utilized as an autograft for anterior cruciate ligament (ACL) reconstruction of patients with acute ACL rupture and grade III medial collateral ligament (MCL) injury. We investigated the efficacy and safety of this alternative autograft compared with autologous hamstring tendon (HT). Biomechanical testing of the graft options was performed and compared with the native ACL. Thirty-eight patients with acute ACL ruptures and grade III MCL injuries were treated with ACL reconstruction with a doubled autologous PLT or quadrupled autologous HT. Knee stability and function was evaluated clinically with the Lachman test and KT-2000 arthometer as well as subjectively with functional scores. Effects on the donor ankle were evaluated by biomechanical testing. The ultimate tensile strengths of doubled PLT and quadrupled HT were significantly higher than that of the native ACL and the ultimate tensile strength of doubled PLT was comparable with that of quadrupled HT. There were no significant differences in clinical or functional scores between the two groups. There were no significant differences in pre- and postoperative biomechanical testing of the donor ankle. PLT is a suitable alternative autograft for an ACL reconstruction in patients with a concomitant grade III MCL injury without a significant biomechanical disadvantage to the ankle donor site.
Erhöhte Stressvulnerabilität bei Großstadtbewohnern
Authors: Lederbogen F. , Meyer-Lindenberg A.
Published: September 2018

Hintergrund: Psychische Erkrankungen, insbesondere Schizophrenie, Depression und Angsterkrankungen, treten bei Bewohnern großer Städte häufiger auf als bei Menschen, die in kleinen Städten, Dörfern oder ländlicher Umgebung leben. Es gibt gute Argumente für die Annahme, dass der Faktor „urbane Umgebung“ im Zusammenwirken mit der genetischen Disposition eine kausale Rolle bei der Risikoerhöhung spielt. Als risikoerhöhendes wirksames Agens der urbanen Umgebung favorisieren viele Experten soziale Stressoren wie soziale Isolation oder fehlende soziale Unterstützung. Diese Annahme wird durch aktuelle Forschungsergebnisse der Neurowissenschaft gestützt, die eine höhere Aktivierung bestimmter Hirnareale unter sozial-evaluativem Stress bei Menschen urbaner Herkunft nachweisen. Diese Befunde sprechen für eine höhere Stressvulnerabilität von Großstadtbewohnern. Ergebnis: Die betroffenen Hirnstrukturen spielen eine wesentliche Rolle bei der Stressverarbeitung, sind aber auch bei der Genese der oben genannten Erkrankungen beteiligt. Der Aufenthalt in der Natur hat nach neuesten Daten eine ausgleichende Wirkung auf diese Hirnstrukturen. Diese Befunde unterstreichen die Bedeutung psychosozialer Stressoren im urbanen Raum, aber auch die einer fehlenden natürlichen Umgebung.
Laplace deep level transient spectroscopy on self-assembled quantum dots
Authors: Schnorr L. , Heinzel T. , Scholz S. , Ludwig A. , Wieck A. D.
Published: September 2018

Self-assembled InAs quantum dots in a GaAs matrix are studied by Laplace deep level transient spectroscopy (LDLTS). This technique is demonstrated to be complementary to the well-established capacitance spectroscopy concepts and is particularly well suited for characterization of quantum dot layers with large separations from conductive layers. In comparison to conventional deep level transient spectroscopy, LDLTS can also be applied in the tunneling regime where the lifetimes of the confined states are independent of temperature, while in the thermal regime, LDLTS has a superior selectivity. The problems encountered hitherto with this technique are demonstrated to originate from the ill-posed character of the inverse Laplace transform and can be solved by a properly adapted choice of the regularization parameter.
Faraday-Talbot effect: Alternating phase and circular arrays
Authors: Sungar N. , Sharpe J. P. , Pilgram J. J. , Bernard J. , Tambasco L. D.
Published: September 2018

A hydrodynamic analog to the optical Talbot effect may be realized on the surface of a vertically shaken fluid bath when a periodic array of pillars protrudes from the fluid surface. When the pillar spacing is twice or one and a half times the Faraday wavelength, we observe repeated images of the pillars projected in front of the array. Sloshing inter-pillar ridges act as sources of Faraday waves, giving rise to self-images. Here, we explore the emergence of Faraday-Talbot patterns when the sloshing ridges between pillars have alternating phases. We present a simple model of linear wave superposition and use it to calculate the expected self-image locations, comparing them to experimental observations. We explore how alternating phase sources affect the Faraday-Talbot patterns for linear and circular arrays of pillars, where curvature allows for magnification and demagnification of the self-imaging pattern. The use of an underlying wavefield is a subject of current interest in hydrodynamic quantum analog experiments, as it may provide a means to trap walking droplets.
Observation of geodesic acoustic mode in EAST using Doppler backscattering system
Authors: Zhang X. H. , Liu A. D. , Zhou C. , Hu J. Q. , Wang M. Y. , Feng X. , Li C. H. , Yang X. M. , Sang L. , Ai J. Q.
Published: September 2018

This paper presents an investigation of the geodesic acoustic mode (GAM) using two poloidally separated Doppler backscattering systems in Experimental Advanced Superconducting Tokamak. Each system allows for the simultaneous measurement of turbulence rotation velocity and density fluctuations with high precision. With the Doppler backscattering systems, the GAM frequency, the symmetric feature of poloidal flow fluctuations, and the interaction between GAM and turbulence are surveyed. The results of bispectral analysis show a clear interaction of GAM with the ambient turbulence. A clear measurement of GAM in the envelope of plasma density fluctuations using Doppler backscatter system is shown, and the modulations of the turbulence perpendicular velocity on the density turbulence are correlated at two different poloidal position.
Ultra-dispersive anomalous diffraction from Pancharatnam-Berry metasurfaces
Authors: Gao Ninghui , Zhang Di , Ren Mengxin , Wu Wei , Cai Wei , Zhang Xinzheng , Xu Jingjun
Published: September 2018

Achieving ultra-dispersive diffractions is fundamentally important to improve the chromatic resolution of spectrometers for numerous applications, such as Raman measurements, atom and molecule identification, and so on. Gratings, as traditionally widely used diffraction elements, disperse chromatic light into different angles according to the phase matching condition, which resorts to the transverse reciprocal vectors of the grating lattice. Mathematically, gratings show higher diffraction dispersion for larger diffraction angles. Either increasing grating line frequencies or steepening the groove angles is adopted to enlarge the deflection angles. However, all of them cause problems of near-zero diffraction efficiency and complicated fabrication. Here, we realize an ultra-dispersive diffraction in the framework of metasurfaces using an alternative phase matching strategy, in which the contributions of both the reciprocal vectors of the lattice and the local wave vectors arisen by the phase gradient are considered simultaneously. The diffraction angle of more than 80° is achieved with the resulting dispersion 4 times larger than the Littrow grating counterparts.
Hot phonon and carrier relaxation in Si(100) determined by transient extreme ultraviolet spectroscopy
Authors: Cushing Scott K. , Zürch Michael , Kraus Peter M. , Carneiro Lucas M. , Lee Angela , Chang Hung-Tzu , Kaplan Christopher J. , Leone Stephen R.
Published: September 2018

The thermalization of hot carriers and phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps, following photoexcitation of the indirect transition to the Δ valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation with density functional theory. The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of phonons involved in inter- and intra-valley electron-phonon scattering, and the population of phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
Diabatic model for electrochemical hydrogen evolution based on constrained DFT configuration interaction
Authors: Holmberg Nico , Laasonen Kari
Published: September 2018

The accuracy of density functional theory (DFT) based kinetic models for electrocatalysis is diminished by spurious electron delocalization effects, which manifest as uncertainties in the predicted values of reaction and activation energies. In this work, we present a constrained DFT (CDFT) approach to alleviate overdelocalization effects in the Volmer-Heyrovsky mechanism of the hydrogen evolution reaction (HER). This method is applied a posteriori to configurations sampled along a reaction path to correct their relative stabilities. Concretely, the first step of this approach involves describing the reaction in terms of a set of diabatic states that are constructed by imposing suitable density constraints on the system. Refined reaction energy profiles are then recovered by performing a configuration interaction (CDFT-CI) calculation within the basis spanned by the diabatic states. After a careful validation of the proposed method, we examined HER catalysis on open-ended carbon nanotubes and discovered that CDFT-CI increased activation energies and decreased reaction energies relative to DFT predictions. We believe that a similar approach could also be adopted to treat overdelocalization effects in other electrocatalytic proton-coupled electron transfer reactions, e.g., in the oxygen reduction reaction.
Role of Gd spin ordering on magnetocaloric effect and ferromagnetism in Sr substituted Gd2CoMnO6 double perovskite
Authors: Sahoo R. C. , Das Sananda , Nath T. K.
Published: September 2018

The phenomenon of magnetocaloric effect occurring around the ordering temperatures for Gd2−xSrxCoMnO6 (x = 0 and 0.5) has been investigated in order to disclose the effects of Sr substitution on the individual collinear Gd spin order. It is shown that 25% Sr substitution of Gd ions significantly suppresses the independent spin order, leading to enhancement of ferromagnetism. As a result, magnetic entropy change (−ΔSM) increases from +0.9 J kg−1 K−1 to +3.7 J kg−1 K−1 at Curie temperature for a change in magnetic field (ΔH) = 6.9 T. On the other hand, the −ΔSM changes sign at Neel temperature due to the effect of Sr substitution. We have also observed noticeably large −ΔSM (∼+25.84 J kg−1 K−1) and (∼+21.01 J kg−1 K−1) for ΔH = 6.9 T at 4f-4f negative coupling temperature (T < 10 K) of x = 0 and x = 0.5 samples, respectively.
Destabilization of resistive plasma resistive wall mode by anisotropic thermal transport
Authors: Bai Xue , Liu Yueqiang , Gao Zhe , Xia Guoliang , Yang Sanxiang
Published: September 2018

Both an analytic model and the toroidal MARS-F code [Liu et al., Phys. Plasmas 7, 3681 (2000)] have been employed to study the effect of the anisotropic thermal transport on the stability of the resistive wall mode (RWM) in resistive tokamak plasmas. The results show that thermal transport destabilizes the resistive plasma RWM, by effectively eliminating the Glasser-Greene-Johnson favorable average curvature stabilization associated with the resistive layer [Glasser et al., Phys. Fluids 7, 875 (1975)]. Modification of the mode eigenfunction is also observed in MARS-F computations, due to the presence of the anisotropic thermal transport.
Dependence of power conversion properties of perovskite solar cells on operating temperature
Authors: Liu Gang , Zhou Conghua , Wan Fang , Li Kangming , Yuan Yongbo , Gao Yongli , Lu Yunzhang , Yang Bingchu
Published: September 2018

Power conversion properties of perovskite solar cells are studied in the temperature range of 310 K to 240 K (and recovering back). As the temperature lowers down, the fill factor (FF) decreases while the open circuit voltage (VOC) increases in the case of reverse scans (scanning from positive voltages to negative ones). The decreased FF is ascribed to the increased resistance of charge transport materials (both TiO2 and Spiro-OMeTAD) as well as the increased interfacial charge transfer resistance, while the increased VOC is due to retarded recombination which is revealed by the transient photovoltage decay measurement. Hysteresis appears in the current-voltage curves, but it shrinks with temperature decreasing and even vanishes as the temperature becomes lower than 270 K. Mott-Schottky capacitance analysis shows that ion migration exists in the device, especially for temperatures >270 K. The “S shape” current-voltage characteristic is observed at lowered temperatures, which is caused by retarded charge extraction across the interface between the active layer and charge-transport materials. Similar power conversion properties are observed when elevating the temperature from 240 K to 310 K; thus, the temperature-sensitive behavior is reversible. The observed behavior is compared with silicon solar cells. The study shows that lowering the temperature is harmful to the charge extraction processes of perovskite solar cells. Highly conductive charge-transport materials are needed for the devices to operate in a colder environment.
Spin-current diodes based on germanene and stanene subjected to local exchange fields
Authors: Zheng Jun , Chi Feng , Guo Yong
Published: September 2018

We theoretically propose a spin-current diode based on germanene and stanene nanoribbons. The results reveal that the germanene or stanene nanoribbon simultaneously under x- and z-direction local exchange fields exhibits excellent rectification characteristics, and that the spin current is blocked in a certain range of spin voltage. The proposed spin-current diodes have three main features: (1) the breakdown voltage of the diodes can be controlled by the strength of exchange fields; (2) the polarity direction of the diodes can be reversed just by adjusting the direction of local exchange fields; and (3) the spin diode effects can be well maintained at 300 K room temperature. All of the results indicate that the proposed germanene and stanene nanosystems are promising candidates for spintronic devices.
Flash-sintering of antimony telluride and its thermoelectric properties
Authors: Mikami Masashi , Kinemuchi Yoshiaki , Kubo Kazuya , Uchiyama Naoki , Miyazaki Hidetoshi , Nishino Yoichi
Published: September 2018

This study set out to examine the flash sintering of thermoelectric materials. A finite element method analysis of electric current activated/assisted sintering with an insulating mold suggested that the use of a sufficiently high Joule-heating rate, such as >10 000 K/s, relative to the thermal diffusion rate of the mold material, can realize uniform sample heating. Based on the analysis results, the sintering of Sb2Te3, a typical thermoelectric material, was conducted with a current feed duration of 1 s, using a sintering apparatus that had been specially devised for flash-sintering. Although a slight reduction in the density and degree of grain alignment was observed, the crystallographic phase was unaffected by the rapid heating, with the thermoelectric performance of the Sb2Te3 sample prepared by the 1-s sintering being comparable with that of a sample that had been conventionally sintered at 773 K for 3 min. This significant reduction in the sintering time can result in the energy consumption for the sintering process being decreased to less than 1% of that required for conventional current sintering. This significant energy-conservation effect of the flash sintering should be appealing from a practical point of view, especially for the fabrication of those thermoelectric materials used for power generation and aimed at energy recovery.
Photodetachment spectroscopy of cold trapped NH2− near threshold
Authors: Lakhmanskaya Olga , Simpson Malcolm , Murauer Simon , Kokoouline Viatcheslav , Wester Roland
Published: September 2018

We have studied photodetachment of the amidogen anion NH2− as a function of photon energy near the detachment threshold. The detachment spectrum is obtained over the energy range of 6190–6355 cm−1 from the loss rate of the anions from a cryogenic radiofrequency multipole ion trap. By modeling all accessible rotational state-to-state photodetachment transitions, we can assign rotational state-specific thresholds to the measured spectrum. In this way, we have determined the electron affinity of NH2 to be 6224 ± 1 cm−1.