bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupled hydroxyl and ether functionalisation in EAN derivatives: the effect of hydrogen bond donor/acceptor groups on the structural heterogeneity studied with X-ray diffractions and fixed charge/polarizable simulations
Authors: Ramondo Fabio , Gontrani Lorenzo , Campetella Marco
Published: May 2019

A combination of X-ray diffraction with molecular simulations is used to describe complex ionic liquids, and the pros and cons of different ε and polarisable force fields are discussed.
Synergetic light trapping effects in organic solar cells with a patterned semi-transparent electrode
Authors: Ren Hao , Ren Xingang , Huang Zhixiang , Wu Xianliang
Published: May 2019

We have established new dual light trapping structures that improve the electrical and optical properties of OSCs.
Nanoscale PDA disassembly in ionic liquids: structure–property relationships underpinning redox tuning
Authors: Ambrico Marianna , Manini Paola , Ambrico Paolo F. , Ligonzo Teresa , Casamassima Giuseppe , Franchi Paola , Valgimigli Luca , Mezzetta Andrea , Chiappe Cinzia , d'Ischia Marco
Published: May 2019

An integrated EPR and electrical impedance spectroscopy approach to predict ionic liquid-mediated tuning of the redox properties of polydopamine nanoparticles.
Predicting dielectric constants of pure liquids: fragment-based Kirkwood–Fröhlich model applicable over a wide range of polarity
Authors: Bouteloup Rémi , Mathieu Didier
Published: May 2019

A hierarchy of models yields reliable predictions for dielectric constants of liquids.
An efficient bifunctional electrocatalyst based on a nickel iron layered double hydroxide functionalized Co3O4 core shell structure in alkaline media
Authors: Tahira Aneela , Ibupoto Zafar Hussain , Vagin Mikhail , Aftab Umair , Abro Muhammad Ishaq , Willander Magnus , Nur Omer
Published: May 2019

An electrocatalyst based on a nickel iron layered double hydroxide functionalized Co3O4 core shell structure.
Au/Co promoted CeO2 catalysts for formaldehyde total oxidation at ambient temperature: role of oxygen vacancies
Authors: Rochard Guillaume , Giraudon Jean-Marc , Liotta Leonarda Francesca , La Parola Valeria , Lamonier Jean-François
Published: May 2019

Cobalt enables formation of additional oxygen vacancies in Au/Co–CeO2 and significantly boosts the ambient oxidation of formaldehyde.
Au2+ cannot catalyze conversion of methane to ethene at low temperature
Authors: Shuman Nicholas S. , Ard Shaun G. , Sweeny Brendan C. , Pan Hanqing , Viggiano Albert A. , Keyes Nicholas R. , Guo Hua , Owen Cameron J. , Armentrout P. B.
Published: May 2019

The previously reported conversion of methane to ethene catalyzed by Au2+ at thermal energies is investigated through a combination of experiment and theory. The conversion is found not to occur, in-line with well-established thermodynamics.
Probing the existing state of Cu(ii) in a Cu–Al spinel catalyst using N2O decomposition reaction with the aid of conventional characterizations
Authors: Hou Xiaoning , Qin Fajie , Qing Shaojun , Liu Yajie , Li Lindong , Gao Zhixian , Qin Yong
Published: May 2019

The spinel and interacting Cu(ii) species have no activity for N2O decomposition, while free Cu(ii) shows activity.
The role of speciation of Ni2+ and its interaction with the support for selectivity and stability in the conversion of ethylene to propene
Authors: Stoyanova Mariana , Bentrup Ursula , Atia Hanan , Kondratenko Evgenii V. , Linke David , Rodemerck Uwe
Published: May 2019

Highly dispersed Ni2+ anchored on Al sites of silica–alumina by grafting presents outstanding selectivity in ethylene conversion to propene.
Mono- and bimetallic amidinate samarium complexes – synthesis, structure, and hydroamination catalysis
Authors: Kazeminejad Neda , Münzfeld Luca , Gamer Michael T. , Roesky Peter W.
Published: May 2019

Two similar amidinate samarium catalysts were synthesized in order to investigate the difference between a monometallic and a bimetallic system in the catalytic hydroamination cyclization reaction.
Binding and activity of polybrominated diphenyl ether sulfates to thyroid hormone transport proteins and nuclear receptors
Authors: Qin Wei-Ping , Li Chuan-Hai , Guo Liang-Hong , Ren Xiao-Min , Zhang Jian-Qing
Published: May 2019

Polybrominated diphenyl ethers sulfates (PBED sulfates), phase-II metabolites of hydroxylated PBDEs (OH-PBDEs), play important roles in their disruption effects on the thyroid hormone (TH) system.
Electrochemical anion pool synthesis of amides with concurrent benzyl ester synthesis
Authors: Dissanayake D. M. M. Mevan , Melville Alex D. , Vannucci Aaron K.
Published: May 2019

An atom economic, electrochemical, concurrent synthesis of amides and benzoic esters.
The biphasic effect of ABA triblock copolymers on the self-assembly of surfactants: insight from dissipative particle dynamics
Authors: Li Jiawei , Wang Junfeng , Yao Qiang , Zhang Yan , Yan Youguo , Zhang Jun
Published: May 2019

ABA triblock copolymers have been demonstrated to be able to produce a biphasic effect on the self-assembly of surfactants.
Bismuth drugs tackle Porphyromonas gingivalis and attune cytokine response in human cells
Authors: Cheng Tianfan , Lai Yau-Tsz , Wang Chuan , Wang Yi , Jiang Nan , Li Hongyan , Sun Hongzhe , Jin Lijian
Published: May 2019

Periodontitis is the leading cause of severe tooth loss and edentulism in adults worldwide and is closely linked to systemic conditions such as diabetes and cardiovascular disease. Porphyromonas gingivalis is the key pathogen in periodontitis. Herein, we provided the first evidence that bismuth drugs suppress P. gingivalis in its planktonic, biofilm, and intracellular states. In total, 42 bismuth-associated proteins were identified including its major virulent factors (e.g., gingipains, hemagglutinin HagA, and fimbriae). Bismuth perturbed its iron acquisition, disturbed the energy metabolism and virulence, and deactivated multiple key enzymes (e.g., superoxide dismutase and thioredoxins). Moreover, bismuth inhibited its biofilm formation and disrupted the 3-day matured biofilms. Notably, the internalized P. gingivalis in various human cells (e.g., human gingival epithelium progenitors, HGEPs) was oppressed by bismuth but not the commonly used antibiotic metronidazole. Importantly, bismuth drugs enabled the counteraction of immuno-inflammatory responses in different host cells perturbed by P. gingivalis. The production of IL-6 and IL-8 attenuated by P. gingivalis in both of native and IL-1β-stimulated HGEPs was restored, while the bacterium-enhanced expression of IL-6, IL-1β, and TNFα in THP-1 macrophages was alleviated. This proof-of-concept study brings prospects for the potential reposition of the routinely used anti-Helicobacter pylori bismuth drugs to better manage inflammatory diseases such as periodontitis and P. gingivalis-related complex systemic disorders.
Ultrafast rotational motions of supported nanoclusters probed by electron diffraction
Authors: Vasileiadis Thomas , Skountzos Emmanuel N. , Foster Dawn , Coleman Shawn P. , Zahn Daniela , Krečinić Faruk , Mavrantzas Vlasis G. , Palmer Richard E. , Ernstorfer Ralph
Published: May 2019

Femtosecond electron diffraction is established as goniometer of ultrafast nanocrystal rotations.
On the emission pattern of nanoscopic emitters in planar anisotropic matrix and nanoantenna structures
Authors: Zhang Pu , Ren Peng-Long , Chen Xue-Wen
Published: May 2019

The impacts of matrix anisotropy and nanoantenna on the emission of single emitters have been rigorously studied for implications in emerging quantum nanophotonics.
Advances in portable electrospinning devices for in situ delivery of personalized wound care
Authors: Yan Xu , Yu Miao , Ramakrishna Seeram , Russell Stephen J. , Long Yun-Ze
Published: May 2019

Kinds of portable electrospinning devices for in situ personal wound care including hand-held spinneret, battery powered and generator powered ones were reviewed.
4′-C-Trifluoromethyl modified oligodeoxynucleotides: synthesis, biochemical studies, and cellular uptake properties
Authors: Zhou Yifei , Zang Chuanlong , Wang Huawei , Li Jiajun , Cui Zenghui , Li Qiang , Guo Fengmin , Yan Zhiguo , Wen Xin , Xi Zhen , Zhou Chuanzheng
Published: May 2019

Introducing a 4′-C-trifluoromethyl (4′-CF3) modification into oligodeoxynucleotides (ODNs) leads to improved nuclease resistance and increased cell permeability.
Antinociceptive activity of thiazole-containing cyclized DAMGO and Leu-(Met) enkephalin analogs
Authors: Harris Hannah M. , Eans Shainnel O. , Ganno Michelle L. , Davis Jennifer C. , Dooley Colette T. , McLaughlin Jay P. , Nefzi Adel
Published: May 2019

A newly developed Hantzsch-based macrocyclization strategy provided cyclic DAMGO and enkephalin analogs with improved oral bioavailability while retaining significant agonist activity.
NitroketeneN,S-acetals: synergistic building blocks for the synthesis of heterocycles
Authors: Saigal Saigal , Khan Sarfaraz , Rahman Habibur , Shafiullah Shafiullah , Khan Md. Musawwer
Published: May 2019

This review highlights the synthesis of several kinds of nitroketeneN,S-acetals and their applications in the synthesis of different kinds of heterocyclic compounds.
Decolorization and degradation analysis of Disperse Red 3B by a consortium of the fungus Aspergillus sp. XJ-2 and the microalgae Chlorella sorokiniana XJK
Authors: Tang Weihua , Xu Xiaolin , Ye Bang-Ce , Cao Peng , Ali Asghar
Published: May 2019

The consortium of fungi and microalgae exhibited simultaneous removal of color, nutrients and COD in simulated wastewater.
Single crystal growth and structure analysis of type-I (Na/Sr)–(Ga/Si) quaternary clathrates
Authors: Urushiyama Hironao , Morito Haruhiko , Yamane Hisanori
Published: May 2019

Single crystals of (Na/Sr)–(Ga/Si) quaternary type-I clathrates, Na8−ySryGaxSi46−x, were synthesized by evaporating Na from a mixture of Na–Sr–Ga–Si–Sn in a 6 : 0.5 : 1 : 2 : 1 molar ratio at 773 K for 12 h in an Ar atmosphere.
Detecting early stage structural changes in wild type, pathogenic and non-pathogenic prion variants using Markov state model
Authors: Jani Vinod , Sonavane Uddhavesh , Joshi Rajendra
Published: May 2019

Markov state model to find out the differences between WT, E200K and E219K systems.
Ammonia borane dehydrogenation and selective hydrogenation of functionalized nitroarene over a porous nickel–cobalt bimetallic catalyst
Authors: Miao Hui , Ma Kelong , Zhu Huiru , Yin Kun , Zhang Ying , Cui Yumin
Published: May 2019

Porous nickel–cobalt bimetallic catalyst realizes selective hydrogenation of nitrobenzene with in situ produced hydrogen through hydrolysis of ammonia borane.
Copper–cobalt catalysts supported on mechanically mixed HZSM-5 and γ-Al2O3 for higher alcohols synthesis via carbon monoxide hydrogenation
Authors: Ge Xuan , Sun Hang , Dong Kun , Tao Yanqi , Wang Qi , Chen Yazhong , Zhang Genlei , Cui Peng , Wang Ye , Zhang Qinghong
Published: May 2019

CuCo bimetallic catalysts over the mixed supports showed smaller average particle size, better dispersion of cobalt and copper species, and good activity for higher alcohols synthesis.
Preparation of core–shell structured metal–organic framework@PANI nanocomposite and its electrorheological properties
Authors: Wen Qingkun , Ma Lili , Wang Chengwei , Wang Baoxiang , Han Rongjiang , Hao Chuncheng , Chen Kezheng
Published: May 2019

Core–shell-structured MIL-125@PANI nanocomposites were synthesized, which can exhibit smart electrorheological behavior under an external electric field.
Synthesis of aminyl biradicals by base-induced Csp3–Csp3 coupling of cationic azo dyes
Authors: Liu Yizhu , Varava Paul , Fabrizio Alberto , Eymann Léonard Y. M. , Tskhovrebov Alexander G. , Planes Ophélie Marie , Solari Euro , Fadaei-Tirani Farzaneh , Scopelliti Rosario , Sienkiewicz Andrzej , Corminboeuf Clémence , Severin Kay
Published: May 2019

Deprotonation of cationic azo dyes results in the formation of aminyl biradicals.
Correction: Gold–carbonyl group interactions in the electrochemistry of anthraquinone thiols self-assembled on Au(111)-surfaces
Authors: Wagner Michal , Qvortrup Katrine , Grier Katja E. , Ottosen Mikkel R. , Petersen Jonas O. , Tanner David , Ulstrup Jens , Zhang Jingdong
Published: May 2019

Correction for ‘Gold–carbonyl group interactions in the electrochemistry of anthraquinone thiols self-assembled on Au(111)-surfaces’ by Michal Wagner et al., Chem. Sci., 2019, 10, 3927–3936.
Glyme-based liquid–solid electrolytes for lithium metal batteries
Authors: Nojabaee M. , Popovic J. , Maier J.
Published: May 2019

The development of stable electrolytes for lithium metal batteries is urgently required.
Alloying for orbital alignment enables thermoelectric enhancement of EuCd2Sb2
Authors: Zheng Liangtao , Li Wen , Wang Xiao , Pei Yanzhong
Published: May 2019

Alloying EuCd2Sb2 with EuZn2Sb2 enables a valence band alignment and a reduction in lattice thermal conductivity resulting in a substantial thermoelectric improvement.
Tunable “soft and stiff”, self-healing, recyclable, thermadapt shape memory biomass polymers based on multiple hydrogen bonds and dynamic imine bonds
Authors: Song Fei , Li Zhaoshuang , Jia Puyou , Zhang Meng , Bo Caiying , Feng Guodong , Hu Lihong , Zhou Yonghong
Published: May 2019

We synthesized “thermadapt” biomass polymers with shape memory, ultrahigh stretchability or rigidity, remarkable self-healing efficiency, recyclability, and reusable adhesiveness.
A MOF-mediated strategy for constructing human backbone-like CoMoS3@N-doped carbon nanostructures with multiple voids as a superior anode for sodium-ion batteries
Authors: Yang Su Hyun , Park Seung-Keun , Kim Jin Koo , Kang Yun Chan
Published: May 2019

Human backbone-like CoMoS3@N-doped carbon nanostructures with multiple voids are successfully prepared by a metal–organic framework-based strategy and applied as anode materials for sodium ion batteries.
A yellow-emissive carbon nanodot-based ratiometric fluorescent nanosensor for visualization of exogenous and endogenous hydroxyl radicals in the mitochondria of live cells
Authors: Zhou Danling , Huang Hong , Wang Yangang , Wang Yan , Hu Zuming , Li Xi
Published: May 2019

A ratiometric fluorescent nanosensor with high sensitivity was developed for visualization of hydroxyl radicals in the mitochondria of live cells.
Hemocompatibility investigation and improvement of near-infrared persistent luminescent nanoparticle ZnGa2O4:Cr3+ by surface PEGylation
Authors: Jiang Ying , Li Yuan , Richard Cyrille , Scherman Daniel , Liu Yingshuai
Published: May 2019

ZnGa2O4:Cr3+ hemocompatibility was systematically investigated from the aspects of hemolysis, erythrocyte morphology, coagulation and complement system activation, and greatly improved by surface PEGylation.
Achiral H-shaped liquid crystals exhibiting an electric-field-induced chiral nematic phase
Authors: Sayama Shoumi , Yoshizawa Atsushi
Published: May 2019

Newly designed achiral H-shaped nematic liquid crystals exhibit an electric-field-induced chiral nematic phase showing domains with opposite helical senses.
Non-doped and doped circularly polarized organic light-emitting diodes with high performances based on chiral octahydro-binaphthyl delayed fluorescent luminophores
Authors: Wu Zheng-Guang , Yan Zhi-Ping , Luo Xu-Feng , Yuan Li , Liang Wei-Qiu , Wang Yi , Zheng You-Xuan , Zuo Jing-Lin , Pan Yi
Published: May 2019

Two circularly polarized delayed fluorescent materials were applied in non-doped and doped CP-OLEDs with |gEL| up to 2.9 × 10−3, an EQEmax of 12.4% and a low efficiency roll-off.
Assets focus risk management framework for critical infrastructure cybersecurity risk management
Authors: Kure Halima Ibrahim , Islam Shareeful
Published: May 2019

Critical infrastructure (CI) is vital for the overall economic growth and its reliable and safe operation is essential for a nation's stability and people's safety. Proper operation of the assets is essential for such a system and any threats that could negatively impact the asset could have a severe disruption. Risk management is an important aspect of the protection of CI. There are several frameworks and methodologies for identifying assets, quantifying and analysing vulnerabilities. However, there is a lack of focus on the interdependencies among the assets and cascading effect of the inherent vulnerabilities on the asset. This study attempts to bridge that gap by presenting a novel asset focus risk management approach for the CI. It presents a systematic methodology for identifying and analysing critical assets, their potential vulnerabilities, threats and risks facing CI. This work taking into account cascading vulnerability impacts on assets leading to threats and causing risk. The authors use a running example from a smart grid system to demonstrate the usability of the approach. The result shows that some assets are prioritised and more vulnerable than other assets for the power grid system and it can severely impact on the overall business continuity.
Distributed noise‐resilient economic dispatch strategy for islanded microgrids
Authors: Chen Feixiong , Chen Minyou , Xu Zhao , Guerrero Josep M. , Wang Le Yi
Published: May 2019

Economic dispatch (ED) plays an important role in economic operation of the microgrid (MG). However, the communication links among distributed generators (DGs) may practically be corrupted by additive noise, resulting in erroneous deviations from ED commands. To deal with such issues, this study proposes a distributed noise‐resilient ED strategy for islanded MG. Owing to consensus‐based implementation, the proposed ED strategy is implemented in a fully distributed manner, which enables peer‐to‐peer communication among DGs without the necessity of a central controller. In addition, the proposed ED strategy involves post‐iterate averaging technique to further enhance its convergence under additive communication noise. In this way, different from the existing ED strategies, the proposed ED strategy is fully distributed and resilient to the communication noise. Furthermore, the effectiveness of the proposed ED strategy is evaluated on an islanded MG, where the communication links are corrupted by different levels of additive noise. Finally, in order to fully take account of the uncertainty and stochastic nature of different operation scenarios, the Monte‐Carlo simulations are carried out, of which the simulation results demonstrate that the proposed ED strategy is superior to the existing ED strategies, in terms of the convergence property under additive communication noise.
Inter‐harmonic parameters estimation in power grid based on accelerated PSO and T5R11 window
Authors: Xu Yanchun , Du Yufei , Li Zhenhua , Lu Mi
Published: May 2019

A novel method on inter‐harmonic parameters estimation is proposed. It contains two steps: pre‐calculation and solution optimisation. An interpolated‐discrete fourier transform (DFT)‐based algorithm with a fifth‐order‐triangular and eleventh‐order‐rectangular (T5R11) window is applied in the pre‐calculation process. Owing to mainlobe interferences caused by inter‐harmonics in the frequency domain, the accelerated particle swarm optimisation (PSO) algorithm is proposed to optimise the solution of pre‐calculation. Three aspects in the PSO are accelerated including utilising the especial DFT expression of T5R11 window, applying a changing inertia weight and locking the frequency. From the view of estimating accuracy, the errors caused by spectral leakage can be restrained to a degree of 10−11 by using T5R11 window, and the relative errors of parameters could be optimised to a degree of 10−5 at the tenth generation in the accelerated PSO. More simulations show that the proposed method can address many complex situations caused by inter‐harmonics, and corresponding detection accuracies satisfy the requirements of national and international standards.
Pattern of Lipid Abnormalities Among South Asian Indians With Cushing’s Syndrome and the Short Term Impact of Surgical Correction of Hypercortisolism
Authors: Dhingra Atul , Ganie Mohd , Dharmshaktu Pramila , Chakraborty Semanti , Jyotsna Viveka , Gupta Nandita
Published: May 2019

Atherosclerotic cardiovascular events are one of the common causes of mortality in patients with Cushing’s syndrome (CS). Atherogenic dyslipidemia is more common among South Asian Indians as compared to other ethnicities and is likely to worsen among patients with CS. This retrospective study was done over 5 years at a single institute to evaluate the pattern of lipid abnormalities in subjects with CS and the changes in lipid parameters after surgical control of hypercortisolemia. The study was done in two parts. In the first part, records of patients with CS diagnosed over 3 years were retrospectively reviewed. Hormonal and metabolic parameters including fasting plasma glucose (FPG), post prandial plasma glucose (PPPG), HbA1c, serum lipids, serum cortisol and plasma ACTH were recorded. In the second part, lipid parameters were rechecked among patients who underwent surgery and a median follow up of 4±2 months after remission. Out of the 126 patients diagnosed with endogenous CS over 3 years, 100 patients were eligible for inclusion in the study. At baseline, sixty five (65%) patients had dyslipidemia as defined by the NCEP-ATPIII criteria. 47 out of 63 (74.6%) subjects achieved remission after surgical management of CS. 32 (68.1%) of these patients had dyslipidemia prior to surgery. After excluding 1 death, 26 of 46 (56.5%) subjects had dyslipidemia after the follow up period. Lipid abnormalities are common among South Asian Indian subjects with endogenous CS and the pattern persists in most of them, 3 months after surgical correction of hypercortisolism.
Selenium and Polycystic Ovary Syndrome; Current Knowledge and Future Directions: A Systematic Review
Authors: Hajizadeh-Sharafabad Fatemeh , Moludi Jalal , Tutunchi Helda , Taheri Ehsaneh , Izadi Azimeh , Maleki Vahid
Published: May 2019

Polycystic ovary syndrome (PCOS), as the most common endocrine disorder in reproductive-aged women, is recognized by hyperandrogenism and insulin resistance. Selenium (Se) potentially possesses therapeutic effects on PCOS due to antioxidant and insulin-like properties. This systematic review evaluates the potential role of Se in the complications of PCOS. A systematic review was performed on published studies reporting the effects of Se on PCOS. Three major databases including PubMed, Scopus, and Google Scholar were searched until December 2018. A total of 7 human studies and two in vitro studies met the inclusion criteria. Two out of three case-control studies showed that serum Se levels tend to decrease in patients with PCOS. Of four studies that evaluated the impact of Se supplementation on insulin resistance, only one study showed protective effects of Se against insulin resistance. Two out of three studies reported the antioxidant effect of Se. Few studies investigating anti-androgenic effect of Se presented controversial results. There were three studies that evaluated the anti-hyperlipidemic effect of Se, of which two surveys indicated the lowering effects of Se on VLDL and LDL-cholesterol. The reviewed studies confirmed inverse relationships between serum Se levels and some androgenic hormones in PCOS. Se is able to attenuate insulin resistance and dyslipidemia. The available data are currently insufficient to support the protective effects of Se on PCOS.
The Relationship between the Anteroposterior Diameter of the Patellar Tendon, Pain and Functionality in Volleyball Players – An Observational Study
Authors: Calvo Gonell Alfonso , Macia Soler Loreto , Moncho Joaquin
Published: May 2019

Objective To determine whether the anteroposterior (AP) diameter of the patellar tendon in volleyball players is associated with a greater sensation of pain and decreased functionality.

Material and Methods A descriptive, observational, cross-sectional study conducted on volleyball players. The scores on the Victorian Institute of Sport Assessment–Patella (VISA-P) scale were registered, together with the visual analogue scale (VAS) and the AP diameter of the patellar tendon, at 5 and at 10 mm distal to the inferior pole of the patella. The demographic, anthropometric and playing characteristics were registered and multiple linear regression models were constructed in order to analyze the relationship between the study variables.

Results The final sample comprised 112 players. The AP diameter was greater in men and showed a positive significant association with the score on the VAS scale and a negative significant association with the VISA-P for both tendons after adjusting for the remaining variables.

Conclusions The measurement of the AP diameter of the patellar tendon may be useful for the prevention of sports injuries in volleyball players as a greater tendon diameter is significantly associated with increased perceived pain and decreased functionality. Future studies should include a biomechanical analysis of jump and reception techniques.
Nonlinear Fokker-Planck equations in super-diffusive and sub-diffusive regimes
Authors: Casas Gabriela A. , Nobre Fernando D.
Published: May 2019

Anomalous-diffusion phenomena are very common in nature and may be suitably described by means of nonlinear Fokker-Planck equations, characterized by specific types of nonlinear diffusion contributions. The most explored situations in the literature consist in nonlinear diffusion contributions written as a power of the probability; these are directly associated with nonextensive statistical mechanics. In this work, we investigate two special limits of such a diffusion contribution, namely, the exponential and logarithmic ones, corresponding, respectively, to superdiffusive and subdiffusive regimes. An H-theorem is proven, relating these Fokker-Planck equations to entropic forms; moreover, the stationary states of these equations are shown to coincide with the equilibrium states, obtained by extremization of the associated entropic forms. Equilibrium distributions are computed in particular cases, being mostly characterized by long tails in the exponential case, whereas compact-support distributions always appear in the logarithmic one. The present results enlarge the applicability of nonlinear Fokker-Planck equations to a wider range of anomalous-diffusion phenomena, particularly those in special limits of super- and subdiffusion regimes.
Multiplicity and concentration of solutions for a fractional Schrödinger equation via Nehari method and pseudo-index theory
Authors: Liu Min , Tang Zhongwei
Published: May 2019

We study a nonlinear fractional Schrödinger equation motivated by nonlocal quantum mechanics. Under suitable assumptions on the potentials, we explore the existence, concentration, convergence, and decay estimates of ground state solutions for this equation. Moreover, the multiplicity of solutions is constructed via pseudo-index theory, and the existence of sign-changing solutions is obtained via the Nehari method.
Series expansions of the deflection angle in the scattering problem for power-law potentials
Authors: Chiron D. , Marcos B.
Published: May 2019

We present a rigorous study of the classical scattering for any two-body interparticle potential of the form v(r) = g/rγ, with γ > 0, for repulsive (g > 0) and attractive (g < 0) interactions. We first derive an explicit series expansion of the deflection angle in the impact factor b. Then, we study carefully the modifications of the results when a regularization (softening) is introduced in the potential at small scales. We check and illustrate all the results with the exact integration of the equations of motion.
Critical role of histone tail entropy in nucleosome unwinding
Authors: Parsons Thomas , Zhang Bin
Published: May 2019

The nucleosome is the fundamental packaging unit for the genome. It must remain tightly wound to ensure genome stability while simultaneously being flexible enough to keep the DNA molecule accessible for genome function. The set of physicochemical interactions responsible for the delicate balance between these naturally opposed processes have not been determined due to challenges in resolving partially unwound nucleosome configurations at atomic resolution. Using a near atomistic protein-DNA model and advanced sampling techniques, we calculate the free energy cost of nucleosome DNA unwinding. Our simulations identify a large energetic barrier that decouples the outer and the inner DNA unwinding into two separate processes, occurring on different time scales. This dynamical decoupling allows the exposure of outer DNA at a modest cost to ensure accessibility while keeping the inner DNA and the histone core intact to maintain stability. We also reveal that this energetic barrier arises from a delayed loss of contacts between disordered histone tails and the DNA and is, surprisingly, largely offset by an entropic contribution from these tails. Implications of this enthalpy entropy compensation for the regulation of nucleosome stability and genome function are discussed.
Numerical study of the landslide tsunami in the South China Sea using Herschel-Bulkley rheological theory
Authors: Ren Zhiyuan , Zhao Xi , Liu Hua
Published: May 2019

The Herschel-Bulkley rheological theory is used to describe the viscoplastic debris landslide flow. The shallow water equations considering the time-dependent deformation of the seafloors are adopted to simulate the generation, propagation, and run-up of the landslide induced tsunami. The one-way coupled method of the landslide induced tsunami is implemented through satisfying the kinematic bottom boundary condition. The 1998 Papua New Guinea landslide tsunami is simulated to validate the numerical model by comparing with measurements. We found that the mechanism of the 1992 Hainan Island tsunami in the South China Sea is due to a submarine landslide by comparing the numerical results between earthquake and landslide. With respect of the Baiyun slide, the effects of remolding rate, initial, and residual yield strength on landslide and tsunami are studied numerically. To distinguish the potential landslide tsunami hazard in the South China Sea, the scenarios of the landslides with the volume of 10, 50, 100, and 200 km3 in the Baiyun slide and 1200 km3 in the Brunei slide are presented. Comparison with the nondeformation model in the near-field illustrates the crucial role of rheological property in the landslide tsunami modeling. Furthermore, the characteristics of the propagation of the landslide tsunami in the South China Sea and coastal hazards are analyzed.
Electromigration-induced leakage current enhancement and its anisotropy in single crystal TiO2
Authors: Long Daniel , Creange Nicole , Moballegh Ali , Dickey Elizabeth C.
Published: May 2019

Time-dependent increases in electrical conductivity in dielectrics exposed to a direct-current voltage bias can be detrimental to device reliability and lifetime, while the same phenomenon may be exploited for resistive switching functionality. The applied electric field induces the electromigration of charged point defects, resulting in spatially inhomogeneous stoichiometry and modifications in the electrode electrostatics. Herein, we monitor the time-dependent changes in leakage current in rutile TiO2 with platinum electrodes. Current–voltage measurements before and after the extended electrical biasing demonstrate that changes in the electrostatics of the cathode Schottky barrier are responsible for the time-dependent increases in leakage current. We also find that electromigration is accelerated along the ⟨001⟩ relative to the ⟨010⟩ crystallographic direction in contrast to what would be predicted by high-temperature diffusion kinetics. We find the observed anisotropic behavior to be consistent with a change in the defect charge state of the titanium interstitials and dominant transport path at lower temperatures. A comparison of optical color front migration kinetics to the temporal evolution of leakage current further supports the interpretation that ionic electromigration near the cathode interface is responsible for the increased leakage current in the electrically degraded state.
Disappeared deep charge-states transition levels in the p-type intrinsic CsSnCl3 perovskite
Authors: Zhang Junyu , Su Jie , Lin Zhenhua , Liu Mengyu , Chang Jingjing , Hao Yue
Published: May 2019

Lead-free inorganic perovskites are promising for optoelectronic applications. Understanding their phase diagram and defect properties is beneficial to predict the stable phase and applications. Here, taking CsSnCl3 as an example, the stability and defect properties are investigated systemically. The results show that the stoichiometric CsSnCl3 can only be grown in a narrow area determined by Sn and Cs chemical potentials. No matter what the Sn condition is, both acceptor defects (Cs- and Sn-vacancies with low charge states) are formed spontaneously with negative formation energies, and the donor defects are difficult to be formed with high formation energies. Interestingly, these charge-state transition levels induced by such stable defects are in the valence band. Meanwhile, no deep acceptor and donor states are formed in the bandgap. In addition, although the Fermi levels can vary in a wide range, the Fermi levels are pinned in the valence band, irrespective of the atmospheric conditions, leading to p-type CsSnCl3 with high hole density and low electron density. Such electronic characters are elucidated in detail by the atomic orbitals and structural deformations. Our studies provide an insight view of the defect properties of CsSnCl3 and provide a valuable guideline for CsSnCl3 fabrication and further modulation.
Measuring low vapor pressures employing the Knudsen effusion technique and a magnetic suspension balance
Authors: Kendler Ricarda , Dreisbach Frieder , Seif Reza , Pollak Stefan , Petermann Marcus
Published: May 2019

A new Knudsen effusion apparatus employing a magnetic suspension balance (MSB) to measure low vapor pressures <1 Pa is presented. The intention of the work is developing a method for measuring vapor pressures that covers a wider range of pressure than established procedures do. A cooled condensation plate is used to collect a large fraction of effused molecules which have left a Knudsen cell. This fraction is calculated from the cosine law of effusion with the geometry of the system. The condensation plate is cooled indirectly with liquid nitrogen so that the molecules which impinge on the plate condense at its surface. The mass increase of the condensation plate is continuously measured with the MSB. The new system is tested with benzoic acid at 298–313 K and with anthracene at 343 and 353 K. Good results with a deviation lower than 5% are achieved with benzoic acid at 298 K. However, the deviation of our results from reference vapor pressures increases with increasing temperature. This behavior may result from not fully isothermal conditions in the Knudsen cell.
Investigation of supersonic turbulent flows over a sphere by fully resolved direct numerical simulation
Authors: Mao Chaoli , Jin Tai , Luo Kun , Fan Jianren
Published: May 2019

In this work, a fully resolved direct numerical simulation study of the interaction between supersonic turbulent flow and inertial particle is carried out. For the compressible flow, an eighth-order bandwidth optimization weighted essentially nonoscillatory scheme is used for shock capturing, and the central finite difference scheme is used for the spatial discretization of diffusion terms. The three-dimensional ghost zone immersed boundary method is adopted for solid-fluid interface identification. These numerical schemes are integrated in a direct numerical simulation solver, and its validation is demonstrated by comparing to several benchmark cases. Such a developed method is then used to attack the problem of an upstream supersonic turbulent flow over a spherical particle. Three cases with different inflow turbulence intensities are studied. It is shown that with the turbulence intensity increasing the drag force coefficient presents a smaller relative increase compared to the incompressible situation. Analysis of the bow shock-turbulence interaction is also reported. Similar to the normal shock-turbulence interaction, both the Kolmogorov and Taylor scales decrease after being compressed by the shock. Moreover, both the streamwise and transverse Reynolds stresses have a peak at the shock position. These results indicate the significance of taking the effects of shock into consideration when modeling the modulation of a solid particle to the compressible turbulence.
The drag reduction performance of low Reynolds number pulsating flow in flexible rectangular channels
Authors: Huang Qi , Si Chao , Zhao Chuang-Yao , Zhong Ying-Jie , Deng Kai , Hu Yan-Jun
Published: May 2019

This work employed theoretical and experimental methods to study the drag reduction performance of flexible channels for low Reynolds number pulsating flow. A novel theoretical model was proposed to describe flow in a flexible rectangular channel. According to the model, the drag reduction of the flexible channel was speculated. Subsequently, experiments were carried out to verify the theoretical results and to illuminate the drag reduction performance of the flexible channel in detail under the impacts of pulsating frequency, nondimensional velocity amplitude, average Reynolds number, and the thickness of the flexible wall. The results indicated that the flexible channel exhibited superior drag reduction performance for pulsating flow as compared to that for steady flow. Meanwhile, the drag reduction rate increased with the increase of pulsating frequency, nondimensional velocity amplitude, and average Reynolds number, and smaller thickness of the flexible wall was in favor of drag reduction at the same flow parameters. Moreover, the current experimental data were utilized to establish a correlation predicting the drag reduction rate of the flexible channel for pulsating flow, which fits 76.4% of 195 data within ±25%.
Instrumentation for automated and quantitative low temperature compaction and sintering
Authors: Floyd Richard , Lowum Sarah , Maria Jon-Paul
Published: May 2019

This report describes the design, operation, and capabilities of a semiautomated uniaxial press with in situ measurement of platen displacements designed to facilitate, understand, and improve compaction and densification of particulate materials contained in conventional metal dies under modest temperatures. While not exclusive to one implementation, the instrumentation is particularly well-suited to study cold sintering. The instrumentation shares similarities to dilatometry, given the ability to monitor pellet compaction, and calorimetry, given the ability to monitor phase transitions by their molar volume signatures. Pursuant to these similarities, we refer to this device as a sinterometer. A critical benefit to this automation is a new ability to conduct experiments unattended for indefinite amounts of time under constant pressure while collecting quantitative data. We demonstrate densification profile computation (i.e., sintegram) using this instrument, including methods to account for the thermal expansion background of the metal die. A set of examples are provided where this stable and long-term data collection allows one to identify densification mechanisms and phase transformations that occur during cold sintering, which would be extremely time consuming, or impossible, to extract using a conventional, manual press.
Evolution of wave pulses in fully nonlinear shallow-water theory
Authors: Ivanov S. K. , Kamchatnov A. M.
Published: May 2019

We consider evolution of wave pulses with formation of dispersive shock waves in framework of fully nonlinear shallow-water equations. Situations of initial elevations or initial dips on the water surface are treated, and motion of the dispersive shock edges is studied within the Whitham theory of modulations. Simple analytical formulas are obtained for asymptotic stage of evolution of initially localized pulses. Analytical results are confirmed by exact numerical solutions of the fully nonlinear shallow-water equations.
Possible observation of quantum spin-nematic phase in a frustrated magnet
Authors: Kohama Yoshimitsu , Ishikawa Hajime , Matsuo Akira , Kindo Koichi , Shannon Nic , Hiroi Zenji
Published: May 2019

Significance

Spin-nematic state in frustrated ferromagnet is one of the exotic states of matter at high magnetic field that could arise as the Bose–Einstein condensation of the two-magnon bound state. Its experimental detection in a real material has long been hindered by the fact that the order parameter of the spin-nematic state, spin quadrupole moment, is hard to detect with conventional magnetic probes available in high magnetic field. Here we design a calorimeter for the pulsed magnetic field studies and perform state-of-the-art measurements of heat capacity and magnetocaloric effect up to 33 T. These results provide strong prima facie evidence for a spin-nematic state in the copper-based mineral volborthite.
Effects of α-tubulin acetylation on microtubule structure and stability
Authors: Eshun-Wilson Lisa , Zhang Rui , Portran Didier , Nachury Maxence V. , Toso Daniel B. , Löhr Thomas , Vendruscolo Michele , Bonomi Massimiliano , Fraser James S. , Nogales Eva
Published: May 2019

Acetylation of K40 in α-tubulin is the sole posttranslational modification to mark the luminal surface of microtubules. It is still controversial whether its relationship with microtubule stabilization is correlative or causative. We have obtained high-resolution cryo-electron microscopy (cryo-EM) reconstructions of pure samples of αTAT1-acetylated and SIRT2-deacetylated microtubules to visualize the structural consequences of this modification and reveal its potential for influencing the larger assembly properties of microtubules. We modeled the conformational ensembles of the unmodified and acetylated states by using the experimental cryo-EM density as a structural restraint in molecular dynamics simulations. We found that acetylation alters the conformational landscape of the flexible loop that contains αK40. Modification of αK40 reduces the disorder of the loop and restricts the states that it samples. We propose that the change in conformational sampling that we describe, at a location very close to the lateral contacts site, is likely to affect microtubule stability and function.
Generation, transcriptome profiling, and functional validation of cone-rich human retinal organoids
Authors: Kim Sangbae , Lowe Albert , Dharmat Rachayata , Lee Seunghoon , Owen Leah A. , Wang Jun , Shakoor Akbar , Li Yumei , Morgan Denise J. , Hejazi Andre A. , Cvekl Ales , DeAngelis Margaret M. , Zhou Z. Jimmy , Chen Rui , Liu Wei
Published: May 2019

Rod and cone photoreceptors are light-sensing cells in the human retina. Rods are dominant in the peripheral retina, whereas cones are enriched in the macula, which is responsible for central vision and visual acuity. Macular degenerations affect vision the most and are currently incurable. Here we report the generation, transcriptome profiling, and functional validation of cone-rich human retinal organoids differentiated from hESCs using an improved retinal differentiation system. Induced by extracellular matrix, aggregates of hESCs formed single-lumen cysts composed of epithelial cells with anterior neuroectodermal/ectodermal fates, including retinal cell fate. Then, the cysts were
en bloc
-passaged, attached to culture surface, and grew, forming colonies in which retinal progenitor cell patches were found. Following gentle cell detachment, retinal progenitor cells self-assembled into retinal epithelium—retinal organoid—that differentiated into stratified cone-rich retinal tissue in agitated cultures. Electron microscopy revealed differentiating outer segments of photoreceptor cells. Bulk RNA-sequencing profiling of time-course retinal organoids demonstrated that retinal differentiation in vitro recapitulated in vivo retinogenesis in temporal expression of cell differentiation markers and retinal disease genes, as well as in mRNA alternative splicing. Single-cell RNA-sequencing profiling of 8-mo retinal organoids identified cone and rod cell clusters and confirmed the cone enrichment initially revealed by quantitative microscopy. Notably, cones from retinal organoids and human macula had similar single-cell transcriptomes, and so did rods. Cones in retinal organoids exhibited electrophysiological functions. Collectively, we have established cone-rich retinal organoids and a reference of transcriptomes that are valuable resources for retinal studies.
Elasticity of individual protocadherin 15 molecules implicates tip links as the gating springs for hearing
Authors: Bartsch Tobias F. , Hengel Felicitas E. , Oswald Aaron , Dionne Gilman , Chipendo Iris V. , Mangat Simranjit S. , El Shatanofy Muhammad , Shapiro Lawrence , Müller Ulrich , Hudspeth A. J.
Published: May 2019

Significance

Our hearing depends on mechanosensitive channels in hair cells of the inner ear. Experiments suggest that each channel is opened by a “gating spring,” an elastic element that conveys displacement of a hair bundle to the channel. Appropriate stiffness of the gating spring permits the discrimination of different sound amplitudes; if the spring is too stiff, then a faint sound will elicit the same response as a loud sound, opening all of a cell’s channels. Although the tip link—a fine molecular filament—might be the gating spring, its properties have remained controversial. Using high-precision optical tweezers, we demonstrate that the mechanical properties of a tip link protein correlate with those of a gating spring in vivo.
Structural and optical studies on PVA capped SnS films grown by chemical bath deposition for solar cell application
Authors: Devi P Mallika Bramaramba , Reddy G. Phaneendra , Reddy K. T. Ramakrishna
Published: May 2019

Tin monosulphide (SnS) thin films capped by PVA have been successfully deposited on glass substrates for cost effective photovoltaic device applications by a simple and low-cost wet chemical process, chemical bath deposition (CBD) at different bath temperatures varying in the range, 50–80 °C. X–ray diffraction analysis showed that the deposited films were polycrystalline in nature, showing orthorhombic structure with an intense peak corresponding to (040) plane of SnS. These observations were further confirmed by Raman analysis. FTIR spectra showed the absorption bands which corresponds to PVA in addition to SnS. The scanning electron microscopy and atomic force microscopy studies revealed that the deposited SnS films were uniform and nanostructured with an average particle size of 4.9 to 7.6 nm. The optical investigations showed that the layers were highly absorbing with the optical absorption coefficient ~105 cm–1. A decrease in optical band gap from 1.92 to 1.55 eV with an increase of bath temperature was observed. The observed band gap values were higher than the bulk value of 1.3 eV, which might be due to quantum confinement effect. The optical band gap values were also used to calculate particle size and the results are discussed.
Magneto-transport properties of the off-stoichiometric Co2MnAl film epitaxially grown on GaAs (001)
Authors: Yu Zhifeng , Wang Hailong , Ma Jialin , Tong Shucheng , Zhao Jianhua
Published: May 2019

We have investigated the magneto-transport properties of an off-stoichiometric full-Heusler alloy Co2MnAl single-crystalline film. The Co1.65Mn1.35Al (CMA) film epitaxially grown on Ⅲ–Ⅴ semiconductor GaAs substrate exhibits perpendicular magnetic anisotropy. The resistivity of the CMA film increases with the temperature T decreasing from 300 to 5 K, showing a semiconducting-like transport behavior. Different activation energies are found in three temperature regions with transition temperatures of 35 and 110 K. In the meanwhile, the remanent magnetization can be described by T
3/2 and T
2 laws in the corresponding medium and high T ranges, respectively. The transition at around 110 K could be attributed to the ferromagnetism evolving from localized to itinerant state. The Curie temperature of the CMA film is estimated to be ~640 K. The intrinsic anomalous Hall conductivity of ~55 Ω–1cm–1 is obtained, which is almost twenty times smaller than that of Co2MnAl.