bluuebunny/crossref_metadata_2025 huggingface dataset:
Unravelling the factors that influence the bio-electrorecycling of carbon dioxide towards biofuels
Authors: Blasco-Gómez R. , Ramió-Pujol S. , Bañeras L. , Colprim J. , Balaguer M. D. , Puig Sebastià
Published: January 2019

Reliable operational procedures for the control of Microbial Electrochemical Technologies (METs) to produce suitable substrates for economically viable downstream applications were investigated.
Advanced statistical analysis of LIBS spectra for the sourcing of obsidian samples
Authors: Syvilay D. , Bousquet B. , Chapoulie R. , Orange M. , Le Bourdonnec F.-X.
Published: January 2019

This paper proposes an advanced statistical analysis method for results obtained by Laser-Induced Breakdown Spectroscopy on obsidian source samples from the Western Mediterranean area.
The third pillar of metal homeostasis inCupriavidus metalliduransCH34: preferences are controlled by extracytoplasmic function sigma factors
Authors: Große Cornelia , Poehlein Anja , Blank Kathrin , Schwarzenberger Claudia , Schleuder Grit , Herzberg Martin , Nies Dietrich H.
Published: January 2019

InC. metallidurans, a network of 11 extracytoplasmic function sigma factors forms the third pillar of metal homeostasis acting in addition to the metal transportome and metal repositories as the first and second pillar.
Organometallic ruthenium anticancer complexes inhibit human peroxiredoxin I activity by binding to and inducing oxidation of its catalytic cysteine residue
Authors: Lin Yu , Wang Jie , Zheng Wei , Luo Qun , Wu Kui , Du Jun , Zhao Yao , Wang Fuyi
Published: January 2019

Peroxiredoxins (Prxs) are a family of ubiquitous antioxidant proteins and the inhibition of Prxs would elevate the reactive oxygen species level so as to induce cancer cell death. The interactions of organometallic ruthenium arene anticancer complexes with proteins play important roles in their mechanisms of action. Herein, we demonstrate that Ru complexes [(η6-arene)Ru(en)Cl]+ (en = ethylenediamine, arene = p-cymene (1), biphenyl (2) and 9,10-dihydrophenanthrene (3)) can inhibit the enzymatic activity of human peroxiredoxin I (Prx-I) in an order of 1 > 3 > 2. Mass spectrometric (MS) analysis revealed that 1–3 coordinated to the catalytic site Cys173 of Prx-I, and partially induced the oxidation of the thiolate to sulfenate. Quantitative MS analysis demonstrated that the higher level of the ruthenation of Cys173 is correlated with the higher inhibitory potency of the Ru complexes against Prx-I, suggesting their binding to Cys173 accounts for their inhibition towards Prx-I.
Designating ligand specificities to metal uptake ABC transporters in Thermus thermophilus HB8
Authors: Mandal Suraj Kumar , Adhikari Rahi , Sharma Anjaney , Chandravanshi Monika , Gogoi Prerana , Kanaujia Shankar Prasad
Published: January 2019

Micronutrients such as metal ions are indispensable for the growth and survival of microorganisms in assorted environmental niches. However, change in cellular concentration of metal ions is pernicious for an organism; thus metal ion homeostasis is crucial for their survival and growth. An eminent mechanism for maintaining metal ion homeostasis in microorganisms is ATP-binding cassette (ABC) transporters, which transport metal ions in their ionic/complex forms across the cell membrane. For the uptake, metals are sequestered by substrate-binding proteins (SBPs) and transferred to transmembrane domains (TMDs) for their transport. In this work, a high-throughput data mining analysis has been performed to identify open reading frames (ORFs) encoding metal-specific ABC transporters in a thermophilic bacterium Thermus thermophilus HB8. In total, 22 ORFs resulting in eight ABC transport systems were identified, which are potentially involved in the uptake of metal ions. This study suggests that three out of eight metal-specific ABC import systems are specific to iron ions. Among the remaining five, two are particular to divalent metal ions such as Mg2+ and Zn2+/Mn2+, another two are for tetrahedral oxyanions such as MoO42− and WO42− and the remaining one imports cyanocobalamin (vitamin B12). Besides these, the results of this study demonstrate the existence of a mechanism where TMD and NBD components are shared among different ABC transport systems hinting that multiple substrates can be imported via a single transporter. This study thus provides the first ever preliminary glimpse into the entire repertoire of metal uptake ABC transporters in a thermophilic organism.
Enzymatic radiosynthesis of a18F-Glu-Ureido-Lys ligand for the prostate-specific membrane antigen (PSMA)
Authors: Lowe Phillip T. , Dall'Angelo Sergio , Fleming Ian N. , Piras Monica , Zanda Matteo , O'Hagan David
Published: January 2019

FDA-PEG-GUL was enzymatically synthesised using the fluorinase in18F-radiolabelled form and shown to efficiently bind the prostate-specific antigen (PSMA) which is upregulated in prostate cancer cells.
Ionic polypeptide tags for protein phase separation
Authors: Kapelner Rachel A. , Obermeyer Allie C.
Published: January 2019

Short ionic polypeptide tags were demonstrated to drive complex coacervation of globular proteins at physiological conditions while maintaining protein activity.
Catalytic asymmetric allylation of aldehydes with alkenes through allylic C(sp3)–H functionalization mediated by organophotoredox and chiral chromium hybrid catalysis
Authors: Mitsunuma Harunobu , Tanabe Shun , Fuse Hiromu , Ohkubo Kei , Kanai Motomu
Published: January 2019

We have developed a catalytic asymmetric nucleophilic allylation of aldehydes using simple alkenes as pronucleophiles without relying on stoichiometric metals.
Chiral cyclopentadienyl RhIII-catalyzed enantioselective cyclopropanation of electron-deficient olefins enable rapid access to UPF-648 and oxylipin natural products
Authors: Duchemin Coralie , Cramer Nicolai
Published: January 2019

Chiral cyclopentadienyl-RhIII complexes catalyze enantioselective cyclopropanations of electron-deficient olefins with N-enoxysuccinimides and are used for syntheses of oxylipins and UPF-648.
MOF derived CoO-NCNTs two-dimensional networks for durable lithium and sodium storage
Authors: Pang Yuanchao , Chen Sheng , Xiao Chunhui , Ma Sude , Ding Shujiang
Published: January 2019

Cobalt oxides encapsulated at the apical postion of by nitrogen-doped carbon nanotubes into two dimensional networks originatinge from the lamellar coordinated polymer for high-performaence lithium/sodium ion batteries.
Metal–organic frameworks for lithium–sulfur batteries
Authors: Zheng Yan , Zheng Shasha , Xue Huaiguo , Pang Huan
Published: January 2019

The applications of metal–organic frameworks and their composites and derivatives in lithium–sulfur batteries are comprehensively summarized and outlooks of them are given in this review.
Bendable and foldable flexible organic solar cells based on Ag nanowire films with 10.30% efficiency
Authors: Lei Tao , Peng Ruixiang , Song Wei , Hong Ling , Huang Jiaming , Fei Nannan , Ge Ziyi
Published: January 2019

Flexible organic solar cells (FOSCs) were fabricated based on Ag nanowire/PET films with PEDOT:PSS composite electrodes. The influence of doping PH1000 with ethylene glycol on the photovoltaic performance has also been investigated. Optimum FOSCs exhibit a PCE of 10.30%. All the FOSCs show excellent flexibility after bending and even upon total folding.
Nanoscale electrical property enhancement through antimony incorporation to pave the way for the development of low-temperature processed Cu2ZnSn(S,Se)4 solar cells
Authors: Zhao Xiangyun , Kou Dongxing , Zhou Wenhui , Zhou Zhengji , Meng Yuena , Meng Qingbo , Zheng Zhi , Wu Sixin
Published: January 2019

The Sb-assisted grain growth and nanoscale band-bending enhancement directly decrease the selenization temperature down to 470 °C.
A universal photoelectrochemical biosensor for dual microRNA detection based on two CdTe nanocomposites
Authors: Hao Nan , Lu Jinwen , Chi Mingji , Xiong Meng , Zhang Ying , Hua Rong , Wang Kun
Published: January 2019

A universal photoelectrochemical biosensor for dual microRNA detection has been successfully developed.
Synthesis and application of P,olefin type axially chiral ligands with sec-alkyl groups
Authors: Mino Takashi , Yamaguchi Daiki , Masuda Chihiro , Youda Junpei , Ebisawa Toshibumi , Yoshida Yasushi , Sakamoto Masami
Published: January 2019

Palladium-catalyzed asymmetric allylic substitution with indoles using a chiral ligand 3b, which have fewer hindered substituents such as secondary alkyl groups than 1-adamantyl group, gave desired products (R)-9 with high enantioselectivities (up to 96% ee).
Analysis of analytical capacity for Fisher–Snedecor F fading channels with different transmission schemes
Authors: Kapucu N. , Bilim M.
Published: January 2019

This Letter presents capacity analysis of Fisher–Snedecor F fading channels under different transmission strategies. To this end, novel analytical expressions are proposed for optimal rate adaptation with constant transmit power, channel inversion with a fixed rate and truncated channel inversion with fixed rate schemes in this Letter. Then, analytical results are illustrated for different fading and shadowing parameter values.
Distributed energy management for community microgrids considering phase balancing and peak shaving
Authors: Liu Guodong , Ollis Thomas B. , Xiao Bailu , Zhang Xiaohu , Tomsovic Kevin
Published: January 2019

In this study, a distributed energy management for community microgrids considering phase balancing and peak shaving is proposed. In each iteration, the house energy management system (HEMS) installed in each house minimises its electricity costs and the costs associated with the discomfort of customers due to deviations in indoor temperature from customers’ set points. At the community level, the microgrid central controller (MCC) schedules the distributed energy resources (DERs) and energy storage based on the received load profiles from customers and the forecast energy price at the point of common coupling. The MCC updates the energy price for each phase based on the amount of unbalanced power between generation and consumption. The updated energy price and unbalanced power for each phase are distributed to the HEMSs on corresponding phases. When the optimisation converges, the unbalanced power of each phase is close to zero. Meanwhile, the schedules of DERs, energy storage systems and the energy consumption of each house are determined by the MCC and HEMSs, separately. In particular, the phase balancing and peak shaving are considered in the proposed distributed energy management model. The effectiveness of the proposed distributed energy management has been demonstrated by case studies.
VU limit pre‐assessment for high‐speed railway considering a grid connection scheme
Authors: Chen Yinyu , Chen Minwu , Tian Zhongbei , Liu Yuanli , Hillmansen Stuart
Published: January 2019

Single‐phase 25 kV AC traction power supply systems (TPSSs) are widely used in high‐speed railways, leading to an increasingly prominent problem of voltage unbalance (VU) in the power grid. To fairly regulate the system VU level, implementing VU limit pre‐assessment is an urgent need. A grid connection scheme including traction transformer selection and exchange phase connection design is a vital part of TPSS design that obviously affects the VU factor of power systems. A uniform mathematical model is established using Thevenin's theorem, which reveals the impact of multiple grid connection schemes on the VU propagation behaviour of a three‐phase grid. Afterwards, under the requirements of IEC/TR 61000‐3‐13, an improved VU limit pre‐assessment process is proposed, which correlates mapping between the grid connection scheme and VU limit. The unbalance compensation calculation is given, adopting the allocation limit; furthermore, the optimal design of the grid connection scheme with minimised compensation capacity as an object is presented. The correctness of the model and the rationality of the pre‐assessment process are verified by a case study.
Multimodal framework based on audio‐visual features for summarisation of cricket videos
Authors: Javed Ali , Irtaza Aun , Malik Hafiz , Mahmood Muhammad Tariq , Adnan Syed
Published: January 2019

Sports broadcasters generate an enormous amount of video content on the cyberspace due to massive viewership all over the world. Analysis and consumption of this huge repository urges the broadcasters to apply video summarisation to extract the exciting segments from the entire video to capture user's interest and reap the storage and transmission benefits. Therefore, in this study an automatic method for key‐events detection and summarisation based on audio‐visual features is presented for cricket videos. Acoustic local binary pattern features are used to capture excitement level in the audio stream, which is used to train a binary support vector machine (SVM) classifier. Trained SVM classifier is used to label audio frame as an excited or non‐excited frame. Excited audio frames are used to select candidate key‐video frames. A decision tree‐based classifier is trained to detect key‐events in the input cricket videos that are then used for video summarisation. Performance of the proposed framework has been evaluated on a diverse dataset of cricket videos belonging to different tournaments and broadcasters. Experimental results indicate that the proposed method achieves an average accuracy of 95.5%, which signifies its effectiveness.
Geometric positions and optical flow based emotion detection using MLP and reduced dimensions
Authors: Khan Gulraiz , Siddiqi Aiman , Ghani Khan Muhammad Usman , Qayyum Wahla Samyan , Samyan Sahar
Published: January 2019

Recent times have witnessed an exponential increase in multimedia specifically visual contents. Emotions are considered an essential part for extracting facial features, evaluating the expressions and as a result predicting the emotions of any person is a trending topic of the time. Based on still images and consecutive video frames, a methodology has been proposed to anticipate the emotions. Facial action coding system (FACS) standards are utilised in the development of an automated visual based emotion detection system worldwide. Employing FACS, the authors estimated facial muscle movement by computing 24 landmark points, 16 mutual distances between them and wrinkles caused due to changing expressions. Canny edge detection has been deployed to calculate the intensity of wrinkles. Geometric positions and optical flow are the key methods deployed in the implemented methodology. The methodology was evaluated on self‐generated, JAFFE dataset and EmotioNet.
Electrical and thermal properties of insulating oil‐based nanofluids: a comprehensive overview
Authors: Huang Zhengyong , Li Jian , Yao Wei , Wang Feipeng , Wan Fu , Tan Yaxiong , Mehmood Muhammad Ali
Published: January 2019

Nanofluids, formed by adding nanoscale particles to insulating oil, are stable and homogeneous suspensions that present advanced performance of electrical insulation and heat dissipation. This study shows a comprehensive literature review based on the related results of nano‐modified insulating oils (both mineral and vegetable insulating oils) to analyse the preparation methods, stability, dielectric spectroscopy, thermal conductivity, breakdown characteristics under AC and DC voltage, the thermal aging performance of nanofluids and oil–paper interaction. Then theoretical models have been introduced to explain the electrical mechanism of nanofluids. In addition, future research is proposed for nanofluids which would be low cost, highly stable and practically applicable to the power transformers.
Transient signal identification of HVDC transmission lines based on wavelet entropy and SVM
Authors: Luo Guomin , Yao Changyuan , Tan Yingjie , Liu Yinglin
Published: January 2019

High‐voltage DC (HVDC) transmission plays an important role in power transmission projects due to its advantages of large transmission power and good control performance. As the main protection of the DC transmission line, transient protection uses the high‐frequency signal generated by fault transient to detect faults, having the characteristics of fast response and high accuracy. However, the HVDC transmission line has complex conditions along the route and is vulnerable to lightning strikes and other accidents, resulting in the occurrence of a variety of transients in the line, which increases the difficulty of fault identification. Being able to reveal signal time‐frequency characteristic, wavelet entropy is an effective tool of signal recognition. This study proposes a method of transient signal identification based on the wavelet entropy and support vector machine (SVM). Firstly, the transient processes of three kinds of signals, including unipolar faults, lightning strike faults, and lightning disturbances, are briefly introduced. Then the time−frequency features of three kinds of transient signals under different scenes are analysed by wavelet entropy. Finally, the training set was used to train the SVM classification model with the signal wavelet entropy being taken as the eigenvector, and the test results validate the effectiveness of the proposed method.
The origin of the two populations of blue stragglers in M30
Authors: Portegies Zwart S.
Published: January 2019

We analyze the position of the two populations of blue stragglers in the globular cluster M30 in the Hertzsprung–Russell diagram. Both populations of blue stragglers are brighter than the cluster’s turn-off, but one population, the blue blue-stragglers, aligns along the zero-age main sequence whereas the other, red population is elevated in brightness (or color) by ∼0.75 mag. Based on stellar evolution and merger simulations we argue that the red population, which composes about 40% of the blue stragglers in M 30, has formed at a constant rate of ∼2.8 blue stragglers per gigayear over the last ∼10 Gyr. The blue population on the other hand formed in a burst that started ∼3.2 Gyr ago at a peak rate of 30 blue stragglers per gigayear with an e-folding time scale of 0.93 Gyr. We speculate that the burst resulted from the core collapse of the cluster at an age of about 9.8 Gyr, whereas the constantly formed population is the result of mass transfer and mergers through binary evolution. In this scenario, about half the binaries in the cluster effectively result in a blue straggler.
Automatic selection of arterial input function in DSC-MRI measurements for calculation of brain perfusion parameters using parametric modelling
Authors: Lipiński Seweryn , Kalicka Renata
Published: January 2019

A novel method and algorithm of automatic selection of arterial input function (AIF) is presented and its efficiency is proved using exemplary DSC-MRI measurements. The method chooses AIF devoted to a particular purpose, which is calculation of perfusion parameters with the use of parametric modelling of DSC-MRI data. The quality of medical diagnosis made on the basis of perfusion parameters depends on the quality of these parameters, which in turn is determined by the quality of the AIF signal. The proposed algorithm combines physiological requirements for AIF with mathematical criteria. The choice of parametric approach, instead of black-box modelling, allows better understanding of the investigated system functioning, as model parameters may be credited with physical interpretation. Furthermore, using multi-compartmental model of the DSC-MRI data with AIF regression function in an exponential form, gives direct, analytic results concerning the basic descriptors of AIF. The method chooses candidates for AIF on the basis of the descriptors quality. This step allows rejecting measurements which do not fulfil fundamental requirements concerning AIF from the physiological point of view. As these requirements are met, the next criterion can be adopted, that is the quality of fitting the regression function to measurements. The final step is choosing the AIF for calculating perfusion parameters with the best accuracy, which is attainable thanks to implementing the AIF devoted particularly to parametric modelling.
Frame-based Stereotactic Biopsy: Description and Association of Anatomical, Radiologic, and Surgical Variables with Diagnostic Yield in a Series of 407 Cases
Authors: Lara-Almunia Monica , Hernandez-Vicente Javier
Published: January 2019

Background and Study Aims Stereotactic biopsy is a versatile, minimally invasive technique to obtain tissue safely from intracranial lesions for their histologic diagnosis and therapeutic management. Our objective was to determine the anatomical, radiologic, and technical factors that can affect the diagnostic yield of this technique. We suggest recommendations to improve its use in clinical practice.

Methods This retrospective study evaluated 407 patients who underwent stereotactic biopsies in the past 34 years. The surgical methodology changed through time, distinguished by three distinct periods. Different stereotactic frames (Todd-Wells, CRW, Leksell), neuroimaging tests, and planning programs were used. Using SPSS software v.23, we analyzed a total of 50 variables for each case.

Results The series included 265 men (65.1%) and 142 women (34.9%) (average age 53.8 years). The diagnostic yield was 90.4%, morbidity was 5.65% (n = 17), and mortality was 0.98% (n = 4). Intraoperative biopsy improved accuracy (p = 0.024). Biopsies of deep lesions (p = 0.043), without contrast enhancement (p = 0.004), edema (p = 0.036), extensive necrosis (p = 0.028), or a large cystic component (p = 0.023) resulted in a worse diagnostic yield. Neurosurgeons inexperienced in stereotactic techniques obtained more nondiagnostic biopsies (p = 0.043). Experience was the clearest predictive factor of diagnostic yield (odds ratio: 4.049).

Conclusions Increased experience in stereotactic techniques, use of the most suitable magnetic resonance imaging sequences during biopsy planning, and intraoperative evaluation of the sample before finalizing the collection are recommended features and ways to improve the diagnostic yield of this technique.
Carpal Kinematics following Sequential Scapholunate Ligament Sectioning
Authors: Padmore Clare , Stoesser Helen , Langohr G. Daniel , Johnson James , Suh Nina
Published: January 2019

Background The scapholunate ligament (SLL) is the most commonly injured intercarpal ligament of the wrist. It is the primary stabilizer of the scapholunate (SL) joint, but the scaphotrapeziotrapezoid (STT) and radioscaphocapitate (RSC) ligaments may also contribute to SL stability. The contributions of SL joint stabilizers have been reported previously; however, this study aims to examine their contributions to SL stability using a different methodology than previous studies.

Purpose The purpose of this in vitro biomechanical study was to quantify changes in SL kinematics during wrist flexion and extension following a previously untested sequential sectioning series of the SL ligament and secondary stabilizers.

Methods Eight cadaveric upper extremities underwent active wrist flexion and extension in a custom motion wrist simulator. SL kinematics were captured with respect to the distal radius. A five-stage sequential sectioning protocol was performed, with data analyzed from 45-degree wrist flexion to 45-degree wrist extension.

Results Wrist flexion and extension caused the lunate to adopt a more extended posture following sectioning of the SLL and secondary stabilizers compared with the intact state (p < 0.009). The isolated disruption to the dorsal portion of the SLL did not result in significant change in lunate kinematics compared with the intact state (p > 0.05). Scaphoid kinematics were altered in wrist flexion following sequential sectioning (p = 0.013). Additionally, disruption of the primary and secondary stabilizers caused significant change to SL motion in both wrist flexion and wrist extension (p < 0.03).

Conclusions The SLL is the primary stabilizer of the SL articulation, with the STT and RSC ligaments playing secondary stabilization roles.

Clinical Relevance Understanding the role primary and secondary SL joint stabilizers may assist in the development of more effective treatment strategies and patient outcomes following SLL injuries.
Future Challenges in Pediatric and Neonatal Sepsis: Emerging Pathogens and Antimicrobial Resistance
Authors: Folgori Laura , Bielicki Julia
Published: January 2019

The incidence of severe infections caused by multidrug-resistant (MDR) pathogens is currently rising worldwide, and increasing numbers of neonates and children with serious bloodstream infections due to resistant bacteria are being reported. Severe sepsis and septic shock due to gram-negative bacteria represent a significant cause of morbidity and mortality, and contribute to high health care costs. Antimicrobial resistance among Enterobacteriaceae represents a major problem in both health care-associated and community-acquired infections, with extended-spectrum β-lactamases (ESBLs) and carbapenem-resistant Enterobacteriaceae (CRE) now presenting the main threat. These infections in adult populations have been associated with poor clinical outcomes, but very limited data have been published so far about risk factors and clinical outcome of ESBL-associated and CRE sepsis in the pediatric population. The treatment of these infections in neonates and children is particularly challenging due to the limited number of available effective antimicrobials. Evidence-based use of new and older antibiotics based on both strategic and regulatory clinical trials is paramount to improve management of these severe infections in neonates and children.
Relationship of Sociodemographic Factors and Outcomes in Functional Rhinoplasty
Authors: Spataro Emily , Olds Cristen , Kandathil Cherian , Most Sam , Nuyen Brian
Published: January 2019

The objective of this article was to compare the effect of such sociodemographic factors as gender, age, marital status, employment status, race, and income on short- and long-term rhinoplasty outcomes using a validated disease-specific instrument—Nasal Obstruction Symptom Evaluation (NOSE) scale, as well as complication and revision rates. Patients who underwent a functional (+/− cosmetic) rhinoplasty with the senior author between January, 1 2012, and September 9, 2017, and had both a preoperative and at least one postoperative NOSE score, were included in the study. Sociodemographic variables of binary gender, age, marital status, employment status, race, and income based on zip code were collected. The primary outcomes were the differences between the preoperative and postoperative NOSE scores with short-term (less than 3 months) and longer-term (greater than 3 months) follow-up. Secondary outcomes were general complications and specifically revision surgery. Standard descriptive statistics, as well as univariable linear and logistic regressions, were conducted with each outcome measure. A total of 341 patients were included in this study. No individual patient-level variables were found to significantly affect the short- or longer-term average change in NOSE scores, although older age trended toward significance in longer-term average change in NOSE scores (p = 0.07). No factors significantly affected the rate of complications or revision surgery in this cohort. The authors found improvement in NOSE scores after rhinoplasty was not related to factors of age, gender, race, employment status, income, and marital status. This cohort also did not demonstrate differential rates in complications or revision surgery based on sociodemographic variables.
Ionic radii of hydrated sodium cation from QTAIM
Authors: Fifen Jean Jules , Agmon Noam
Published: January 2019

The sodium cation is ubiquitous in aqueous chemistry and biological systems. Yet, in spite of numerous studies, the (average) distance between the sodium cation and its water ligands, and the corresponding ionic radii, are still controversial. Recent experimental values in solution are notably smaller than those from previous X-ray studies and ab initio molecular dynamics. Here we adopt a “bottom-up” approach of obtaining these distances from quantum chemistry calculations [full MP2 with the 6-31++G(d,p) and cc-pVTZ basis-sets] of gas-phase Na+(H2O)n clusters, as a function of the sodium coordination number (CN = 2–6). The bulk limit is obtained by the polarizable continuum model, which acts to increase the interatomic distances at small CN, but has a diminishing effect as the CN increases. This extends the CN dependence of the sodium-water distances from crystal structures (CN = 4–12) to lower CN values, revealing a switch between two power laws, having a small exponent at small CNs and a larger one at large CNs. We utilize Bader’s theory of atoms in molecules to bisect the Na+–O distances into Na+ and water radii. Contrary to common wisdom, the water radius is not constant, decreasing even more than that of Na+ as the CN decreases. We also find that the electron density at the bond critical point increases exponentially as the sodium radius decreases.
Dynamic modeling and characteristic analysis of piezoelectric rudder actuator
Authors: Chen Heng , Wang Jun-shan , Chen Chao , Liu Shi-xiang , Chen Hai-peng
Published: January 2019

In this note, dynamic equations of the piezoelectric rudder actuator are established using a numerical method, and the dynamic characteristics are analyzed. A simulation is performed using finite element software to verify the validity of the theory. The results show that an increase in axial force has significant amplification effects on the static displacement output of the bimorph and its rudder actuator, and the axial stiffness of the piezoelectric bimorph is evidently nonlinear against larger axial force. The response time of the rudder actuator is less affected by the axial force and remains in the order of milliseconds under the axial force of 0.85 times the buckling critical load.
Soliton interaction with external forcing within the Korteweg–de Vries equation
Authors: Ermakov Andrei , Stepanyants Yury
Published: January 2019

We revise the solutions of the forced Korteweg–de Vries equation describing a resonant interaction of a solitary wave with external pulse-type perturbations. In contrast to previous work where only the limiting cases of a very narrow forcing in comparison with the initial soliton or a very narrow soliton in comparison with the width of external perturbation were studied, we consider here an arbitrary relationship between the widths of soliton and external perturbation of a relatively small amplitude. In many particular cases, exact solutions of the forced Korteweg–de Vries equation can be obtained for the specific forcings of arbitrary amplitude. We use the earlier developed asymptotic method to derive an approximate set of equations up to the second-order on a small parameter characterising the amplitude of external force. The analysis of exact solutions of the derived equations is presented and illustrated graphically. It is shown that the theoretical outcomes obtained by the asymptotic method are in a good agreement with the results of direct numerical modeling within the framework of forced Korteweg–de Vries equation.
Thermal imaging of buried heterostructure quantum cascade lasers (QCLs) and QCL arrays using CCD-based thermoreflectance microscopy
Authors: Becher N. , Farzaneh M. , Knipfer B. , Sigler C. , Kirch J. , Boyle C. , Botez D. , Mawst L. J. , Lindberg D. F. , Earles T.
Published: January 2019

Thermal profiles of a single-element quantum cascade laser (QCL) and a five-element QCL array at different bias currents, under quasi-continuous-wave (QCW) conditions, are obtained using the charge-coupled device (CCD)-based thermoreflectance imaging technique. Peak temperature changes of 55 K and 105 K are measured on the single-element QCL (operating at 1.2 A) and the central element of the QCL array (operating at 4.2 A), respectively. The average facet temperature of the single QCL device shows a linear relationship with the dissipated power, indicating an effective thermal resistance of Rth = 3.0 ± 0.2 K/W (7%) for the device. The thermal transient behavior of the single QCL device, in response to a 35 μs-wide heating pulse, is also measured. From the transient curve, an effective thermal time constant of τth = 9.5 ± 0.4 μs (4%) is obtained. Experimental results are compared to the results obtained from heat-transfer models for both the single-element and array devices. Thermal profiles show a thermal lensing effect at the facet of the single-element QCL. In the array device, a more pronounced heating is observed at the center of the device while the temperature gradually decreases away from the central element.
Direct evaluation of the force constant matrix in quantum Monte Carlo
Authors: Liu Y. Y. F. , Andrews B. , Conduit G. J.
Published: January 2019

We develop a formalism to directly evaluate the matrix of force constants within a Quantum Monte Carlo calculation. We utilize the matrix of force constants to accurately relax the positions of atoms in molecules and determine their vibrational modes, using a combination of variational and diffusion Monte Carlo. The computed bond lengths differ by less than 0.007 Å from the experimental results for all four tested molecules. For hydrogen and hydrogen chloride, we obtain fundamental vibrational frequencies within 0.1% of experimental results and ∼10 times more accurate than leading computational methods. For carbon dioxide and methane, the vibrational frequency obtained is on average within 1.1% of the experimental result, which is at least 3 times closer than results using restricted Hartree-Fock and density functional theory with a Perdew-Burke-Ernzerhof functional and comparable or better than density functional theory with a semi-empirical functional.
Lattice Boltzmann simulation of double-diffusive natural convection of viscoplastic fluids in a porous cavity
Authors: Kefayati Gholamreza
Published: January 2019

In this paper, a two-dimensional double diffusive natural convection in a porous cavity filled with viscoplastic fluids is simulated. The dimensional and non-dimensional macroscopic equations are presented, employing the Papanastasiou model for viscoplastic fluids and the Darcy–Brinkman–Forchheimer model for porous media. An innovative approach based on a modification of the lattice Boltzmann method is explained and validated with previous studies. The effects of the pertinent dimensionless parameters are studied in different ranges. The extensive results of streamlines, isotherms, and isoconcentration contours, yielded/unyielded regions, and local and average Nusselt and Sherwood numbers are presented and discussed.
Selective upstream influence on the unsteadiness of a separated turbulent compression ramp flow
Authors: Porter Kevin M. , Poggie Jonathan
Published: January 2019

A study of the shock-wave/boundary-layer interaction induced by a compression ramp was carried out using high-fidelity simulations. The objective was to investigate the influence of upstream disturbances on low-frequency separation unsteadiness. Two computations were performed for a 24° compression ramp at Mach 2.25, one highly resolved case and one reduced-resolution case. The reduced-resolution case was run for an extended duration to capture many cycles of low-frequency unsteadiness. Basic flow characteristics, including statistics on the boundary layer, wall pressure, and skin friction, were computed. Frequency spectra were calculated to confirm the presence of low-frequency unsteadiness. The influence of upstream disturbances on large-scale separation unsteadiness was investigated using correlations, filtering, and conditional averaging based on the position of the primary separation shock. Low-frequency unsteadiness was found to be related to structures near the wall (y/δ < 0.5) with a time scale greater than 20δ/U∞, whereas higher frequency separation motion could be attributed to turbulent boundary layer structures with a time scale on the order of δ/U∞. The finding that the separation region responds selectively to certain large-scale, near-wall perturbations in the incoming flow supports a model of separation unsteadiness in which external forcing by certain components of boundary layer turbulence drives a weakly damped global mode of the separation bubble. This contrasts with suggestions that have been made in the literature that the separation region oscillates on its own, as in an amplified global mode.
Computational study of noninteger order system of predation
Authors: Owolabi Kolade M.
Published: January 2019

In this paper, we analyze the stability of the equilibrium point and Hopf bifurcation point in the three-component time-fractional differential equation, which describes the predator-prey interaction between different species. In the dynamics, the classical first-order derivative in time is modelled by either the Caputo or the Atangana-Baleanu fractional derivative of order α,0<α<1. We utilized a fractional version of the Adams-Bashforth formula to discretize these fractional derivatives in time. The results of the linear stability analysis presented are confirmed by computer simulation results.
Demonstration of vector magnetic field sensing by simultaneous control of nitrogen-vacancy centers in diamond using multi-frequency microwave pulses
Authors: Yahata Ken , Matsuzaki Yuichiro , Saito Shiro , Watanabe Hideyuki , Ishi-Hayase Junko
Published: January 2019

An ensemble of nitrogen-vacancy (NV) centers in diamond is a fascinating candidate for realizing a sensitive magnetic field sensor. In particular, since the axes of the NV centers are distributed along four directions, a collection of measurement data from NV centers with different axes provides information on the vector components of a magnetic field. However, in the conventional approach, the low measurement contrast of NV centers limits the sensitivity of vector magnetic field sensing. Recently, to overcome this problem, multi-frequency control of the NV centers has been proposed. The key idea is that four types of NV centers with different axes are simultaneously controlled by multi-frequency microwave pulses. Here, we demonstrate vector magnetic field sensing with an ensemble of NV centers in diamond via such multi-frequency control with pulsed-type measurements. We use Hahn echo pulses and extract information on the vector components of an applied AC magnetic field. We find that the sensitivity of the vector field sensing with multi-frequency control is better than that with single-frequency control for every vector component of a magnetic field.
A simple approach to fiber-based tunable microcavity with high coupling efficiency
Authors: Qing Peng , Gong Jue , Lin Xing , Yao Ni , Shen Weidong , Rahimi-Iman Arash , Fang Wei , Tong Limin
Published: January 2019

We report a simple technique for the realization of fiber-based Fabry-Pérot microcavities with large Q/V values as well as high cavity-to-fiber coupling efficiencies. The open microcavity we demonstrate consists of a flat mirror and a concave mirror on the tip of a single mode optical fiber. Combining hydrofluoric acid chemical wet etching with CO2 laser reflow, we obtain a fiber-tip atomically smooth concave surface with a diameter of 4.7 μm determined by the fiber core size. The concave surface with a spherical profile is automatically aligned with the fiber core, which enables high cavity-to-fiber power coupling efficiency (higher than 90%) with an optimal fiber-tip mirror's radius of curvature based on numerical simulation results. After distributed-Bragg-reflector coating, we have realized a wavelength-tunable open microcavity with a quality factor Q exceeding 1000 and a mode volume V of 13.6 μm3, and laser emission is demonstrated from this microcavity.
Burrows with resources have greater visitation and may enhance mange transmission among wombats
Authors: Martin Alynn M. , Ricardo Hayley , Tompros Adrianna , Fraser Tamieka A. , Polkinghorne Adam , Carver Scott
Published: January 2019

Environmental exposure to Sarcoptes scabiei mites in burrows is considered the dominant mechanism of sarcoptic mange transmission among wombats. We document elevated activity of bare-nosed wombats at a burrow with subterranean water access relative to burrows without this resource, suggesting that some burrows may contribute more to mange transmission than others.
Exposure to atrazine during puberty reduces sperm viability, increases weight gain and alters the expression of key metabolic genes in the liver of male mice
Authors: Cook Laura E. , Finger Bethany J. , Green Mark P. , Pask Andrew J.
Published: January 2019

Atrazine (ATZ) is one of the most widely used herbicides worldwide and is a common contaminant in human drinking water. It disrupts metabolic pathways in plants, and has metabolic and reproductive effects in vertebrates, including humans. Few studies have investigated the effects of exposure to low doses of ATZ, especially during sexual development in males. In this study, we exposed C57BL/6J male mice from weaning for 8 weeks to drinking water containing 0.5mgkg−1 bodyweight (BW) day−1 ATZ, the ‘no observed effect’ level used by the Australian government, or a 10-fold higher dose (5mgkg−1 BW day−1). Mice treated with the low dose of ATZ showed increased total and cumulative weight gain. At 12 weeks of age, there was a significant increase in the percentage of dead spermatozoa in both ATZ-exposed groups, as well as decreased epididymal sperm motility in the low-dose ATZ group. Significant changes in testis and liver gene expression were also observed following ATZ exposure. These data demonstrate that a low dose of ATZ can perturb metabolic and reproductive characteristics in male mice. A chronic reduction in sperm quality and increased weight gain could have negative consequences on the reproductive capacity of males, and further studies should consider the effects of long-term ATZ exposure on male reproductive health.
Regional neutrality evolves through local adaptive niche evolution
Authors: Leibold Mathew A. , Urban Mark C. , De Meester Luc , Klausmeier Christopher A. , Vanoverbeke Joost
Published: January 2019

Biodiversity in natural systems can be maintained either because niche differentiation among competitors facilitates stable coexistence or because equal fitness among neutral species allows for their long-term cooccurrence despite a slow drift toward extinction. Whereas the relative importance of these two ecological mechanisms has been well-studied in the absence of evolution, the role of local adaptive evolution in maintaining biological diversity through these processes is less clear. Here we study the contribution of local adaptive evolution to coexistence in a landscape of interconnected patches subject to disturbance. Under these conditions, early colonists to empty patches may adapt to local conditions sufficiently fast to prevent successful colonization by other preadapted species. Over the long term, the iteration of these local-scale priority effects results in niche convergence of species at the regional scale even though species tend to monopolize local patches. Thus, the dynamics evolve from stable coexistence through niche differentiation to neutral cooccurrence at the landscape level while still maintaining strong local niche segregation. Our results show that neutrality can emerge at the regional scale from local, niche-based adaptive evolution, potentially resolving why ecologists often observe neutral distribution patterns at the landscape level despite strong niche divergence among local communities.
Citation analysis
Authors: Bruhn Mark J.
Published: January 2019

This paper presents series of historiometric studies that exemplify the value of “citation analysis” as an empirical approach to professional literary-critical interpretation, especially with respect to the question of the “literariness” of literary texts. Specifically, the studies show that professional interpreters of Wordsworth’s poetry, across more than a century of time and despite widely varying critical approaches, tend to pay more attention to and therefore more frequently cite lines that involve prospective enjambments. Lines involving nominative noun phrase and retrospective enjambments, however, did not reveal the same correlation with frequency of citation. The studies thus suggest that literariness does indeed have a relatively stable textual component that may be discriminated through citation analysis of professional interpretations of individual literary texts by authors writing in distinct genres of literature and in different periods in literary history.
Living metaphor as the site of bidirectional literary engagement
Authors: Kuiken Don , Douglas Shawn
Published: January 2019

Articulation of an interactive model of literariness calls for separate specification of (a) a text’s perceptible
mode of representation, (b) a reader’s mode of engagement with a text so perceived, and (c) the generative (e.g., creative,
expressive) effects of the interaction between this mode of representation and mode of reader engagement. We present a model that
identifies two aspects of metaphoric textual representation: structured sequences of nominal metaphors and quasi-metaphoric
structures with optional metaphoric construal. This model also distinguishes two modes of reader engagement: expressive enactment
and integrative comprehension (Kuiken & Douglas, 2017). The generativity of
literary reading is located especially within the interplay between expressive enactment and sequences of metaphoric (and
quasi-metaphoric) modes of representation. Evidence suggests that readers reporting expressive enactment also report inexpressible
realizations and a temporal progression leading through epistemic tensions that comprise “living metaphor” (Ricoeur, 1981). Thus the generativity – and aesthetic effects – of literary reading are found within the
departures from conventionality that comprise the emergent meanings of complex metaphoric structures.
P2X7 receptor restrains pathogenic Tfh cell generation in systemic lupus erythematosus
Authors: Faliti Caterina E. , Gualtierotti Roberta , Rottoli Elsa , Gerosa Maria , Perruzza Lisa , Romagnani Andrea , Pellegrini Giovanni , De Ponte Conti Benedetta , Rossi Riccardo L. , Idzko Marco , Mazza Emilia M.C. , Bicciato Silvio , Traggiai Elisabetta , Meroni Pier Luigi , Grassi Fabio
Published: January 2019

Altered control of T follicular helper (Tfh) cells can lead to generation of autoantibodies and autoimmune manifestations. Signaling pathways that selectively limit pathogenic responses without affecting the protective function of Tfh cells are unknown. Here we show that the ATP-gated ionotropic P2X7 receptor restricts the expansion of aberrant Tfh cells and the generation of self-reactive antibodies in experimental murine lupus, but its activity is dispensable for the expansion of antigen-specific Tfh cells during vaccination. P2X7 stimulation promotes caspase-mediated pyroptosis of Tfh cells and controls the development of pathogenic ICOS+ IFN-γ–secreting cells. Circulating Tfh cells from patients with systemic lupus erythematosus (SLE) but not primary antiphospholipid syndrome (PAPS), a nonlupus systemic autoimmune disease, were hyporesponsive to P2X7 stimulation and resistant to P2X7-mediated inhibition of cytokine-driven expansion. These data point to the P2X7 receptor as a checkpoint regulator of Tfh cells; thus, restoring P2X7 activity in SLE patients could selectively limit the progressive amplification of pathogenic autoantibodies, which deteriorate patients’ conditions.