bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic covalent polymer networks via combined nitroxide exchange reaction and nitroxide mediated polymerization
Authors: Jia Yixuan , Matt Yannick , An Qi , Wessely Isabelle , Mutlu Hatice , Theato Patrick , Bräse Stefan , Llevot Audrey , Tsotsalas Manuel
Published: March 2020

This study explores the combination of nitroxide exchange reaction (NER) and nitroxide mediated polymerization (NMP) to prepare structurally tailored and engineered macromolecular networks with dynamically tunable strand lengths.
High-performance III–VI monolayer transistors for flexible devices
Authors: Chen Jianhui , Cai Shuchang , Xiong Rui , Sa Baisheng , Wen Cuilian , Wu Bo , Sun Zhimei
Published: March 2020

The mechanical properties of group III–VI monolayers and sub-10 nm scale device performance of corresponding MOSFETs have been investigated by using density functional theory calculations as well as ab initio quantum transport simulations.
Effect of a liquid environment on single-pulse generation of laser induced periodic surface structures and nanoparticles
Authors: Shih Cheng-Yu , Gnilitskyi Iaroslav , Shugaev Maxim V. , Skoulas Evangelos , Stratakis Emmanuel , Zhigilei Leonid V.
Published: March 2020

Mechanisms of laser-assisted surface nanostructuring and generation of nanoparticles are revealed in a closely integrated computational and experimental study.
Dynamic pH responsivity of triazole-based self-immolative linkers
Authors: Roberts Derrick A. , Pilgrim Ben S. , Dell Tristan N. , Stevens Molly M.
Published: March 2020

Triazole-based self-immolative linkers can be reversibly paused and restarted throughout their elimination cascades in response to environmental pH changes.
Photomechanical actuation of polydimethylsiloxane/carbon black nanocomposite
Authors: Hiremath Shivashankar , Kulkarni Satyabodh M
Published: March 2020

Materials such as carbon black (CB), carbon nanotube, graphene, etc. have been found to deform on exposure to the light source. Introducing these materials into polymers could convert them to photo‐responsive composites. This is demonstrated by the experiment in which polydimethylsiloxane (PDMS) polymer containing CB nanofiller composites is prepared, and its photomechanical actuation from exposure to IR light source is recorded using a laser displacement sensor. The particle size analysis reveals the size of the CB, which is verified by the dynamic light scattering method. The UV–vis–IR spectrophotometer study shows that an increase in the light absorbance capacity of nanocomposites compared to the plain polymer. The PDMS/CB nanocomposite beam exhibited a significant deformation compared to plain PDMS. Deformation of the order of 10–11 mm is observed for a given IR source. The deformation found to have good repeatability but with some thermal hysteresis in cyclic actuation and de‐actuation.
Évaluation des risques liés à l’utilisation de pesticides en culture cotonnière au Mali
Authors: Le Bars Marjorie , Sidibe Fatoumata , Mandart Elisabeth , Fabre Jacques , Le Grusse Philippe , Diakite Cheick Hamalla
Published: March 2020

Au Mali, l’usage des pesticides sur la culture de coton constitue un réel problème de santé publique et pour l’environnement. Cette étude porte sur les risques potentiels correspondant à la « dangerosité » des matières actives présentes dans les pesticides distribués pour le coton. Nous avons recensé 174 pesticides homologués par le Comité sahélien des pesticides (CSP) destinés à la culture du coton, dont 106 insecticides et fongicides et 68 herbicides. Ils sont formulés à partir de 50 matières actives ; 10 sont interdites en Europe et se retrouvent dans 35 produits homologués (soit 20 % des produits disponibles). Un indice de risque de toxicité (IRT) sur la santé des utilisateurs a été calculé pour chacune des 50 matières actives tenant compte de leurs toxicités aiguë et chronique. Il montre que la pendiméthaline et la bifenthrine ont les IRT les plus élevés respectivement pour les herbicides et les insecticides. Un indicateur de contamination des sols et des eaux de surface et souterraine par ces matières actives a été calculé. Il montre qu’une matière active peut présenter un risque important pour la santé et avoir un fort niveau de toxicité pour l’environnement ou avoir un faible impact sur la santé mais présenter un risque élevé pour l’environnement. Une sensibilisation des différents acteurs sur les risques encourus par les pesticides permettrait de réduire leurs impacts sur la santé humaine et l’environnement.
„Ich habe die Vision einer diversen Gesellschaft, in der jeder das Recht auf Chancengleichheit hat“ – Eftychia Kalimana
Authors: Janssen Christina , Kalimana Eftychia
Published: March 2020

Was eine Ergotherapeutin auf die Beine stellen kann, wenn sie für ein Thema brennt, zeigt die Griechin Eftychia Kalimana. Anlässlich des Welttags der Ergotherapie organisierte sie eine Konferenz. Darin ließ sie Referenten und Teilnehmer zu den Themen Menschenrechte, Diversität, soziale Inklusion und Betätigung diskutieren.
Einblick in die Gaming-Welt – Gaming als Betätigung
Authors: Sircar Ayla
Published: March 2020

Schalten Sie auch gerne beim Zocken ab? Immerhin widmen sich etwa 34 Millionen Menschen in Deutschland regelmäßig Smartphone, Spielekonsole oder PC – egal, ob mit Behinderung, durch eine Krankheit beeinträchtigt oder gesund. Dieser Beitrag bietet Ihnen Hilfestellung für die Anliegen Ihrer Gamer-Klienten.
Hepatic Portal Venous Gas: An Ill Omen or a Misleading Sign
Authors: Mehta Shruti , Desai Gunjan S. , Shah Saumil , Mehta Hitesh , Phadke Aniruddha
Published: March 2020

Hepatic portal venous gas (HPVG), a rare radiological finding, is historically considered an ominous sign with 100% mortality rates. The dictum that HPVG warrants surgical intervention is challenged in the recent literature. This is because of the identification of various causes of HVPG other than bowel gangrene. Most of these newly identified causes can be managed conservatively. However, bowel gangrene, if missed, is fatal. Hence, sound clinical judgment and accurate diagnosis based on specific clinical parameters and imaging findings are important. We present a case of a young male with tumor lysis syndrome and neutropenic sepsis. He underwent treatment for a relapse of T-cell acute lymphocytic leukemia and presented with abdominal pain and distension. Computed tomography (CT) scan showed HPVG, and the differential diagnosis was neutropenic colitis or pseudomembranous colitis, with steroid use as the probable cause. The patient was managed conservatively. The case emphasizes that the evaluation for a specific cause of HPVG is important to reduce unnecessary surgery. A succinct literature review provides the reasons for the changing mortality rates.
Splenic Artery Embolization for Nonocclusive Hepatic Artery Hypoperfusion
Authors: Jenner Zachary B. , Di Geronimo Ryan T. , Molano Pilar Bayona , Pillai Rex M.
Published: March 2020

Various minimally invasive, surgical, and laparoscopic interventions are performed for treatment and management of splenic artery steal syndrome in liver transplant and cirrhotic patients. Common approaches include splenic artery banding, ligation, stenting, and embolization to increase hepatic arterial flow. Splenic artery embolization has undergone further development to facilitate timely diagnosis, increase efficacy, decrease adverse outcomes, and improve patient selection. We review the current diagnostic modalities and technical advancements of splenic artery embolization to improve hepatic arterial perfusion in patients with splenic artery steal syndrome.
Nonrecurrent Laryngeal Nerve : A Rare Entity
Authors: P. Shrinath D. Kamath , Rathnakar Pretty , Shetty Kishore
Published: March 2020

The non recurrent laryngeal nerve (nRLN) is a rare abnormal condition that the head and neck surgeon must aware of in order to avoid postoperative morbidity. High index of suspicion, Preoperative recognition of patients with situs inversus, dysphagia lusoria, identification of medialised vagus nerve and meticulous dissection can minimise the risk of injury to nRLN intraoperatively.

We are reporting a case of nRLN observed during hemithyroidectomy for a 53 year old female patient.
EMTN em hospitais dos Municípios do Alto do Tietê
Authors: Bottoni Andrea , Hassan Daniel Zumerkorn , Nacarato Arnaldo , Garnes Sérgio dos Anjos , Bottoni Adriana
Published: March 2020

A desnutrição pode ser definida como um desequilíbrio metabólico causado por diferentes fatores que podem agir individualmente ou combinados como: aumento da necessidade calórico-proteica, inadequado consumo de nutrientes, alterações da composição corporal e funções fisiológicas. No âmbito hospitalar, a desnutrição, desde sua identificação nas décadas de 70, preocupa profissionais da saúde, visto que prejudica a função imune, interferindo na susceptibilidade às infecções, cicatrização e resposta inflamatória, o que pode provocar um aumento no tempo de hospitalização. Desse modo, quanto mais precoce a detecção de pacientes mal nutridos, ou em risco de desnutrição, maior o benefício da Terapia Nutricional (TN). Delineamento do trabalho: estudo prospectivo com perguntas objetivas e descritivaspara avaliar a situação da TN e das EMTNs em hospitais públicos e não públicos dos municípios da região do Alto Tietê pertencentes a grande São Paulo. Nove hospitais foram selecionados para essa análise, por apresentarem os critérios de inclusão requeridos. Apenas 11% dessas instituições manipulavam in loco a nutrição parenteral (NP), cerca de 45% adquiriam os compostos da indústria e a outra metade terceirizava o serviço. Entretanto, todos faziam uso do aparelho de infusão para administração da NP. Apesar de ser exigência da ANVISA, a porcentagem de hospitais que possui a EMTN ativa é bem pequena.
Supervised Machine Learning in Oncology: A Clinician's Guide
Authors: Murali Nikitha , Kucukkaya Ahmet , Petukhova Alexandra , Onofrey John , Chapiro Julius
Published: March 2020

The widespread adoption of electronic health records has resulted in an abundance of imaging and clinical information. New data-processing technologies have the potential to revolutionize the practice of medicine by deriving clinically meaningful insights from large-volume data. Among those techniques is supervised machine learning, the study of computer algorithms that use self-improving models that learn from labeled data to solve problems. One clinical area of application for supervised machine learning is within oncology, where machine learning has been used for cancer diagnosis, staging, and prognostication. This review describes a framework to aid clinicians in understanding and critically evaluating studies applying supervised machine learning methods. Additionally, we describe current studies applying supervised machine learning techniques to the diagnosis, prognostication, and treatment of cancer, with a focus on gastroenterological cancers and other related pathologies.
Multidisciplinary Approach for Liver Transplantation in Patients with Nonalcoholic Steatohepatitis: It Takes a Village
Authors: Tsai Eugenia , Patnaik Ronit , Alkhouri Naim
Published: March 2020

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of liver disease in Western countries, and its aggressive form, nonalcoholic steatohepatitis (NASH), is a leading cause of cirrhosis and end-stage liver disease. The total number of new liver transplantation waitlist registrants with NASH continues to increase rapidly, making NASH the second most common indication for liver transplantation. Compared with recipients for other etiologies, patients with NASH often have higher rates of obesity, diabetes, dyslipidemia, hypertension, kidney disease, and cardiac disease. Many of these medical comorbidities are independently associated with increased preoperative risk and both short- and long-term complications. The presence of these particular risk factors necessitates the need for early detection, medical optimization, and careful preoperative care. Bariatric surgery is an effective strategy for weight loss and ultimately reducing obesity-related medical complications. In select patients, bariatric surgery—before, during, or after liver transplantation—may be useful to help improve posttransplant outcomes. NAFLD/NASH can present after liver transplantation and occurs as either recurrent or de novo disease. Posttransplant NAFLD occurs in the setting of metabolic syndrome, immunosuppression use, and genetic determinants. Future studies and efforts should focus on optimizing medical management strategies to further improve transplant outcomes in patients with NAFLD.
Going beyond polaronic theories in describing charge transport in rubrene single crystals
Authors: Wang Xiao , Dodabalapur Ananth
Published: March 2020

We show that the charge transport properties of single crystals of rubrene can be well described without using polaron theories along the two high-mobility axes. The charge carriers can be considered as holes with coupling to the lattice but not to the degree, which requires the use of polaron theories. It is possible to use the Boltzmann Transport Equation (BTE) in the relaxation time approximation (RTA) to evaluate mobilities due to various scattering mechanisms after introducing a transport reduction factor (PTRF). PTRF takes into account the fraction of charge carriers, which have path lengths that are larger than the lattice constant, and permits the use of the BTE in the RTA even when the magnitude of the overall mobility is lower than the value typically required for the use of the BTE. We are then able to calculate mobilities due to various scattering mechanisms. We calculate the effective electron–phonon coupling constant from the published values for various phonon modes. The values of the effective mass from calculations and measurements reported in the literature vary slightly; we assume an intermediate value for the effective mass. With no fitting parameters needed for calculating temperature-dependent mobilities for trap-free crystals, we are able to get excellent agreement with the measured values along the two high-mobility crystallographic directions. In samples, with some trapping, a small density of exponentially distributed trap states is assumed and gives a very good fit to the measured data. Our work provides strong evidence that it is not necessary to invoke polaronic effects to understand charge transport in rubrene crystals.
Inferring symbolic dynamics of chaotic flows from persistence
Authors: Yalnız Gökhan , Budanur Nazmi Burak
Published: March 2020

We introduce “state space persistence analysis” for deducing the symbolic dynamics of time series data obtained from high-dimensional chaotic attractors. To this end, we adapt a topological data analysis technique known as persistent homology for the characterization of state space projections of chaotic trajectories and periodic orbits. By comparing the shapes along a chaotic trajectory to those of the periodic orbits, state space persistence analysis quantifies the shape similarity of chaotic trajectory segments and periodic orbits. We demonstrate the method by applying it to the three-dimensional Rössler system and a 30-dimensional discretization of the Kuramoto–Sivashinsky partial differential equation in (1+1) dimensions.
A sensitivity-enhanced capacitance readout circuit with symmetric cross-coupling structure
Authors: Yu Tianbao , Deng Lianwen , Jiang Ying , Liao Congwei , Luo Heng , Huang Shengxiang
Published: March 2020

This paper presents a proposed capacitance readout circuit that enables a quadrupled (x4) output strength. A symmetric cross-coupling structure is proposed to amplify the voltage difference between two adjacent channels; hence, the detected signal can be integrated twice every clock cycle. Compared with conventional schematics, the proposed readout circuit shows an increased output strength for integration times within dozens of μs. In addition, the measurements show that the integrator resistors should be less than 1 kΩ to suppress the resistance–capacitance delay effects. Although the proposed capacitance readout circuit is implemented using discrete transistors, it has a good signal integrity at an operating clock cycle of 100 µs. Therefore, the proposed readout circuit is a promising way to detect small capacitance variations with short integration times.
Investigation of the time interval of plasma generation for a high repetition rate laser ion source
Authors: Kashiwagi H. , Yamada K.
Published: March 2020

To apply a laser ion source that generates a high-intensity pulsed beam to high-dose applications, such as ion implantation, a high repetition rate operation with a short pulse interval is required. However, when the pulse interval is shortened, there is a concern that a plasma, which is different from a single pulse plasma generation, may be formed due to the interaction between the preceding and following pulses. We investigated the time interval in which plasma pulses are generated without pulse-to-pulse interaction using a laser ion source with two lasers. In the experiment, a graphite target was irradiated by two laser beams (1064-nm wavelengths) with the same pulse widths (5.4 ns) and energies (15 mJ, 30 mJ, and 45 mJ) at different time intervals ranging from 1000 μs to 0 µs, and the time integrated value corresponding to the total charge amount was calculated from the measured time-of-flight signal of the generated carbon ion current. It was observed that the total charge did not change when the time interval was as low as approximately 100 µs, and the total charge rapidly decreased when the time interval was below approximately 100 µs. Thus, it was determined that the interaction occurs within a time interval of approximately 100 µs.
One-dimensional, surface emitting, disordered Terahertz lasers
Authors: Salemi Luca , Garrasi Katia , Biasco Simone , Crisci Teresa , Beere Harvey E. , Ritchie David A. , Vitiello Miriam S.
Published: March 2020

Quantum cascade lasers are, by far, the most compact, powerful, and spectrally pure sources of radiation at terahertz frequencies, and, as such, they are of crucial importance for applications in metrology, spectroscopy, imaging, and astronomy, among many others. However, for many of those applications, particularly imaging, tomography, and near-field microscopy, undesired artifacts, resulting from the use of a coherent radiation source, can be detrimental. Random lasers can offer a concrete technological solution to the above issue. They, indeed, maintain a high degree of temporal coherence, as traditional lasers, while only exhibiting low spatial coherence, which can allow for the prevention of coherent artifacts, such as speckles. In this study, we report on the development of one-dimensional THz-frequency random wire lasers, patterned on the top surface of a double-metal quantum cascade laser with fully randomly arranged apertures, not arising from the perturbation of a regular photonic structure. By performing finite element method simulations, we engineer photonic patterns supporting strongly localized random modes in the 3.05–3.5 THz range. Multimode laser emission over a tunable-by-design band of about 400 GHz and with ∼2 mW of peak power has been achieved, associated with 10° divergent optical beam patterns. The achieved performances were then compared with those of perturbed Fabry–Perot disordered lasers, showing continuous-wave operation in the 3.5–3.8 THz range with an order of magnitude larger average power output than their random counterpart, and an irregular far field emission profile.
Metalorganic vapor phase epitaxy of wurtzite InP nanowires on GaN
Authors: Kauppinen Christoffer , Haggren Tuomas , Lipsanen Harri , Sopanen Markku
Published: March 2020

The metalorganic vapor phase epitaxy of wurtzite InP nanowires on GaN (0001) is demonstrated. The InP nanowires exhibit the same wurtzite structure as the underlying wurtzite GaN. The photoluminescence studies indicate that the InP nanowires are single-phase wurtzite with high crystalline quality which is supported by transmission and scanning electron microscopy images. The position of the second valence band or valence band splitting energy is also deduced from the photoluminescence data to be ΔAB=30 meV at room temperature. The InP/GaN heterojunction can enable exotic optoelectronic and spintronic experiments and applications. In addition, these results can enable traditional III–V growth on III-N materials for heterojunction devices.
Effect of airflow on the space-time distribution of filaments in dielectric barrier discharge at atmospheric pressure
Authors: Wang Yuying , Yan Huijie , Guo Hongfei , Xu Yongfeng , Fan Zhihui , Ren Chunsheng
Published: March 2020

The effect of flowing air on dielectric barrier discharge excited by alternating voltage was investigated by high-speed video analysis and electrical measurements. The discharge was still in filamentary mode in flowing air, and the space-time distribution of filaments was changed by airflow. With the increase in airflow velocity, the space-time distribution of discharge filaments shown in top view images went through four phases, that is, spot-like distribution, line-like distribution, cotton-like distribution, and stripe-like distribution. Accordingly, the motion and morphology of discharge filaments shown in side view images also presented four phases: remaining still and straight between adjacent cycles, moving and bending downstream, almost remaining still and straight between adjacent cycles, and moving and bending downstream again. Different motions of filaments were considered to be the reason for the changed distribution of filaments in flowing air. In addition, the intensity of discharge in flowing air was enhanced by increasing the gas gap and discharge frequency. At high discharge current, larger airflow velocity was needed to reach phase transition. The changed distribution of micro-discharge remnants in flowing air can be responsible for the phase transition. Micro-discharge remnants redistributed during the time interval of adjacent half-cycle discharges, under the action of various forces, such as electric field force, drag force, repulsive force, electrostatic coupling force, and trap binding force. The changed position of micro-discharge remnants led to the complex motions of discharge filaments and further resulted in the changed space-time distribution of filaments.
Laser frequency shift up to 5 GHz with a high-efficiency 12-pass 350-MHz acousto-optic modulator
Authors: Zhou Chao , He Chuan , Yan Si-Tong , Ji Yu-Hang , Zhou Lin , Wang Jin , Zhan Ming-Sheng
Published: March 2020

We demonstrate a novel laser frequency shift scheme using a 12-pass 350-MHz acousto-optic modulator (AOM). This AOM system shows better performance compared to ordinary acousto-optic modulation schemes. The frequency of the incident laser beam is shifted by 4.2 GHz with the total diffraction efficiency as high as 11%, and the maximum frequency shift is 5 GHz. Combining the ±1st order diffraction, laser signals with up to 10 GHz frequency difference can be obtained, which fulfill most frequency shift requirements of laser cooling and coherent manipulation experiments with alkali metal atoms.
Numerical investigation of control of dynamic stall over a NACA0015 airfoil using dielectric barrier discharge plasma actuators
Authors: Yu Haocheng , Zheng Jianguo
Published: March 2020

The control of dynamic stall over a periodically pitching NACA 0015 airfoil using alternating current (AC) and nanosecond (NS) dielectric barrier discharge (DBD) plasma actuators is investigated by means of numerical simulation. This study employs a two-dimensional unsteady Reynolds averaged Navier–Stokes (URANS) approach to resolve the flow control process. The pulsed AC and NS plasma discharges are modeled by an empirical body force model and a sophisticated self-similar plasma formulation, respectively. Our study concentrates on the resolution of detailed control process of dynamic stall under DBD plasma forcing at two Reynolds numbers (Re) as well as on comparison of AC and NS plasma actuations in terms of control mechanism and authority. It appears that the dynamic stall without control at both moderate Reynolds number of Re = 2.5 × 105 and high Reynolds number of Re = 7.5 × 105 can be categorized into the so-called trailing edge stall. The trailing edge stall initiates with flow reversal near the trailing edge. Regarding the dynamic stall control, it is found that the jet flow produced by AC DBD or residual heat of NS DBD is responsible for inducing large-scale spanwise vortices, which, in turn, dominate the flow control. For the moderate Re flow, AC and NS plasma actuators have comparable performance and both achieve good control authority. However, for the dynamic stall control at high Re, the NS DBD achieves surprising success in enhancing lift of the airfoil and reducing aerodynamic hysteresis, whereas AC DBD nearly has no effect on the flow. It is found that the superiority of the NS plasma actuator over other control means is due to the thermal convection characteristic peculiar to NS plasma discharge. This characteristic makes the NS DBD plasma actuator more flexible in extending its influence region and acquiring a better control effect.
Dispersion of copper oxide species on nanostructured ceria
Authors: Ning Jing , Dong Chunyan , Li Mingrun , Zhou Yan , Shen Wenjie
Published: March 2020

Copper oxides species deposited on ceria rods, particles, and cubes were examined for low-temperature oxidation of CO. It was found that the shape of ceria altered the dispersion and chemical state of copper species considerably. CuOx monolayers and bilayers were formed on ceria rods and particles, while multilayers and faceted particles co-existed on ceria cubes. The formation of Cu+ species at the copper–ceria interface involved a significant charge transfer from copper oxides to the ceria surface via a strong electronic interaction, which was more pronounced on ceria rods. The concentrations of surface Cu+ and oxygen vacancies followed the order rods > particles > cubes, in line with their catalytic activity for CO oxidation at 343 K.
A thermodynamic study of phase transitions and electrocaloric properties of K0.5Na0.5NbO3 single crystals
Authors: Zhao Xinye , Wang Jian-Jun , Chen Long-Qing
Published: March 2020

Lead-free ferroelectrics K1−xNaxNbO3 are promising candidates for sensors and electromechanical and cooling devices. Here, we study the thermodynamics of phase transitions and electrocaloric (EC) properties of K0.5Na0.5NbO3 single crystals subject to electric, thermal, and mechanical stimuli, from which we establish the temperature–pressure and temperature-electric field phase diagrams. The focus is on understanding the pressure effect on the ferroelectric properties of K1−xNaxNbO3, which is critical to develop chemical doping strategies to achieve targeted performances via chemical strain engineering. Under pressure-free conditions, the K0.5Na0.5NbO3 single crystal has a Curie temperature of around 673 K, which is the optimal operating temperature for the EC effect. We show that a hydrostatic pressure of around 7 GPa can reduce the optimal operating temperature to near room temperature, 300 K, at the expense of decreasing the EC temperature change ΔTEC from 5.4 K to 2.4 K when the applied electric field is 10 MV/m. The present work provides a fundamental understanding of the pressure-induced phase transitions and ferroelectric properties and can be employed to guide the future design of K1−xNaxNbO3-based materials.
Strongly localized carriers in Al-rich AlGaN/AlN single quantum wells grown on sapphire substrates
Authors: Frankerl Christian , Nippert Felix , Hoffmann Marc Patrick , Wang Heng , Brandl Christian , Lugauer Hans-Jürgen , Zeisel Roland , Hoffmann Axel , Davies Matthew John
Published: March 2020

Carrier dynamics in AlGaN-based single quantum well (QW) structures grown on sapphire are studied by means of time-integrated and time-resolved photoluminescence spectroscopy (PL) in a wide temperature range from 5 K to 350 K. The samples cover a broad compositional range, with aluminum contents ranging between 42% and 60% and QW widths between 1.5 nm and 2.5 nm. All samples reveal the characteristic “S”-shape temperature dependence of the PL emission energy as frequently reported in InGaN-based systems, albeit with significantly larger localization strengths of up to 60 meV. It is shown that in the compositional range investigated, carrier localization is determined primarily by the QW width and, in contrast, exhibits a much weaker dependence on aluminum concentration. By the combination of time-integrated and time-resolved PL measurements, the localization of carriers is demonstrated to have a significant impact on the recombination dynamics of AlGaN/AlN QWs grown on sapphire, heavily affecting the internal quantum efficiency and efficiency droop even in standard LED operation conditions.
Fine tuning of pattern selection in the cadmium–hydroxide-system
Authors: Papp Paszkál , Bohner Bíborka , Tóth Ágota , Horváth Dezső
Published: March 2020

Controlling self-organization in precipitation reactions has received growing attention in the efforts of engineering highly ordered spatial structures. Experiments have been successful in regulating the band patterns of the Liesegang phenomenon on various scales. Herein, we show that by adjusting the composition of the hydrogel medium, we can switch the final pattern between the classical band structure and the rare precipitate spots with hexagonal symmetry. The accompanying modeling study reveals that besides the modification of gel property, tuning of the time scale of diffusional spreading of hydroxide ions with respect to that of the phase separation drives the mode selection between one-dimensional band and two-dimensional spot patterns.
Cassie–Wenzel wetting transition on nanostructured superhydrophobic surfaces induced by surface acoustic waves
Authors: Sudeepthi A. , Yeo L. , Sen A. K.
Published: March 2020

We report irreversible Cassie–Wenzel wetting transition on a nanostructured superhydrophobic surface employing surface acoustic wave (SAW) vibration. The transition is achieved upon penetration of the liquid into the nanogrooves driven by the inertial energy of the drop imparted by the SAW. However, the filling up of nanopores imposes an energy barrier (Eb) to the transition, which requires the displacement of the initial solid–air interface inside the pores with a solid–liquid interface. We unravel that the relative magnitudes of the input acoustic energy (Eac), and this energy barrier, hence, dictate the occurrence of the wetting transition, with the irreversibility in the transition, therefore, being explained from energy minimization of the system following the transition. In addition, observing the dynamics of the wetting front allowed the different regimes of the wetting transition process to be identified.
Dynamic behaviors of hyperbolic-type memristor-based Hopfield neural network considering synaptic crosstalk
Authors: Leng Yang , Yu Dongsheng , Hu Yihua , Yu Samson Shenglong , Ye Zongbin
Published: March 2020

Crosstalk phenomena taking place between synapses can influence signal transmission and, in some cases, brain functions. It is thus important to discover the dynamic behaviors of the neural network infected by synaptic crosstalk. To achieve this, in this paper, a new circuit is structured to emulate the Coupled Hyperbolic Memristors, which is then utilized to simulate the synaptic crosstalk of a Hopfield Neural Network (HNN). Thereafter, the HNN’s multi-stability, asymmetry attractors, and anti-monotonicity are observed with various crosstalk strengths. The dynamic behaviors of the HNN are presented using bifurcation diagrams, dynamic maps, and Lyapunov exponent spectrums, considering different levels of crosstalk strengths. Simulation results also reveal that different crosstalk strengths can lead to wide-ranging nonlinear behaviors in the HNN systems.
Promoting pepper (Capsicum annuum) photosynthesis via chloroplast ultrastructure and enzyme activities by optimising the ammonium to nitrate ratio
Authors: Zhang Jing , Xie Jianming , Gan Yantai , Coulter Jeffrey A. , Dawuda Mohammed Mujitaba , Yu Jihua , Lv Jian , Li Jing , Zhang Xiaodan , Tang Chaonan , Wang Cheng , Niu Tianhang , Calderón-Urrea Alejandro
Published: March 2020

Optimal plant growth in many species is achieved when the two major forms of N are supplied at a particular ratio. In this pot experiment, the effects of five different ammonium:nitrate ratios (ANRs) (0:100, 12.5:87.5, 25:75, 37.5:62.5, and 50:50) on photosynthesis efficiency in chilli pepper (Capsicum annuum L.) plants were evaluated. The results showed that an ANR of 25:75 increased the contents of chl a, leaf area and dry matter, whereas chl b content was not affected by the ANRs. Regarding chlorophyll fluorescence, an ANR of 25:75 also enhanced the actual photochemical efficiency, photochemical quenching and maximum photosynthetic rate. However, the 0:100 and 50:50 ANRs resulted in higher values for nonphotochemical quenching. An inhibition of maximal photochemical efficiency was found when 50% NH4+ was supplied at the later stage of plant growth. The addition of 25% or 37.5% NH4+ was beneficial for gas exchange parameters and the 25% NH4+ optimised the thylakoid of chloroplasts. Compared with nitrate alone, 12.5–50% NH4+ upregulated glutamate dehydrogenase (GDH), the large subunit and the small subunit of Rubisco. It can be concluded that the 25:75 ANR accelerated N assimilation through active GDH, which provides a material basis for chloroplast and Rubisco formation, resulting in the increased photosynthetic rate and enhanced growth in chilli pepper.
Rift Valley fever: a review
Authors: Bingham John , Jansen van Vuren Petrus
Published: March 2020

Rift Valley fever (RVF) is a mosquito-borne viral disease, principally of ruminants, that is endemic to Africa. The causative Phlebovirus, Rift Valley fever virus (RVFV), has a broad host range and, as such, also infects humans to cause primarily a self-limiting febrile illness. A small number of human cases will also develop severe complications, including haemorrhagic fever, encephalitis and visual impairment. In parts of Africa, it is a major disease of domestic ruminants, causing epidemics of abortion and mortality. It infects and can be transmitted by a broad range of mosquitos, with those of the genus Aedes and Culex thought to be the major vectors. Therefore, the virus has the potential to become established beyond Africa, including in Australia, where competent vector hosts are endemic. Vaccines for humans have not yet been developed to the commercial stage. This review examines the threat of this virus, with particular reference to Australia, and assesses gaps in our knowledge that may benefit from research focus.
Signaling mechanisms of growth hormone-releasing hormone receptor in LPS-induced acute ocular inflammation
Authors: Liang Wei Cheng , Ren Jia Lin , Yu Qiu Xiao , Li Jian , Ng Tsz Kin , Chu Wai Kit , Qin Yong Jie , Chu Kai On , Schally Andrew V. , Pang Chi Pui , Chan Sun On
Published: March 2020

Significance

Emerging evidence indicates that the receptor for growth-hormone–releasing hormone (GHRH-R) is involved in a wide spectrum of extra-pituitary activities, including tumor growth and inflammation. This study elucidates the molecular mechanism of inflammatory processes in acute ocular inflammation mediated by GHRH-R. In human ciliary epithelial cells, the expression of the GHRH-R gene is elevated after lipopolysaccharide insult through the phosphorylation of NF-κB. The activation of GHRH-R stimulates activity of the JAK2/STAT3 pathway, leading to cytokine and chemokine production. In a rat model of endotoxin-induced uveitis, and in human ciliary epithelial cells, antagonists targeting the GHRH-R/JAK2/STAT3–signaling axis alleviate partially the inflammatory responses, supporting a potential therapeutic approach to acute ocular inflammation.
Topological transition in measurement-induced geometric phases
Authors: Gebhart Valentin , Snizhko Kyrylo , Wellens Thomas , Buchleitner Andreas , Romito Alessandro , Gefen Yuval
Published: March 2020

The state of a quantum system, adiabatically driven in a cycle, may acquire a measurable phase depending only on the closed trajectory in parameter space. Such geometric phases are ubiquitous and also underline the physics of robust topological phenomena such as the quantum Hall effect. Equivalently, a geometric phase may be induced through a cyclic sequence of quantum measurements. We show that the application of a sequence of weak measurements renders the closed trajectories, hence the geometric phase, stochastic. We study the concomitant probability distribution and show that, when varying the measurement strength, the mapping between the measurement sequence and the geometric phase undergoes a topological transition. Our finding may impact measurement-induced control and manipulation of quantum states—a promising approach to quantum information processing. It also has repercussions on understanding the foundations of quantum measurement.
Cas9 interrogates DNA in discrete steps modulated by mismatches and supercoiling
Authors: Ivanov Ivan E. , Wright Addison V. , Cofsky Joshua C. , Aris Kevin D. Palacio , Doudna Jennifer A. , Bryant Zev
Published: March 2020

The CRISPR-Cas9 nuclease has been widely repurposed as a molecular and cell biology tool for its ability to programmably target and cleave DNA. Cas9 recognizes its target site by unwinding the DNA double helix and hybridizing a 20-nucleotide section of its associated guide RNA to one DNA strand, forming an R-loop structure. A dynamic and mechanical description of R-loop formation is needed to understand the biophysics of target searching and develop rational approaches for mitigating off-target activity while accounting for the influence of torsional strain in the genome. Here we investigate the dynamics of Cas9 R-loop formation and collapse using rotor bead tracking (RBT), a single-molecule technique that can simultaneously monitor DNA unwinding with base-pair resolution and binding of fluorescently labeled macromolecules in real time. By measuring changes in torque upon unwinding of the double helix, we find that R-loop formation and collapse proceed via a transient discrete intermediate, consistent with DNA:RNA hybridization within an initial seed region. Using systematic measurements of target and off-target sequences under controlled mechanical perturbations, we characterize position-dependent effects of sequence mismatches and show how DNA supercoiling modulates the energy landscape of R-loop formation and dictates access to states competent for stable binding and cleavage. Consistent with this energy landscape model, in bulk experiments we observe promiscuous cleavage under physiological negative supercoiling. The detailed description of DNA interrogation presented here suggests strategies for improving the specificity and kinetics of Cas9 as a genome engineering tool and may inspire expanded applications that exploit sensitivity to DNA supercoiling.
Eye movements support behavioral pattern completion
Authors: Wynn Jordana S. , Ryan Jennifer D. , Buchsbaum Bradley R.
Published: March 2020

The ability to recall a detailed event from a simple reminder is supported by pattern completion, a cognitive operation performed by the hippocampus wherein existing mnemonic representations are retrieved from incomplete input. In behavioral studies, pattern completion is often inferred through the false endorsement of lure (i.e., similar) items as old. However, evidence that such a response is due to the specific retrieval of a similar, previously encoded item is severely lacking. We used eye movement (EM) monitoring during a partial-cue recognition memory task to index reinstatement of lure images behaviorally via the recapitulation of encoding-related EMs or gaze reinstatement. Participants reinstated encoding-related EMs following degraded retrieval cues and this reinstatement was negatively correlated with accuracy for lure images, suggesting that retrieval of existing representations (i.e., pattern completion) underlies lure false alarms. Our findings provide evidence linking gaze reinstatement and pattern completion and advance a functional role for EMs in memory retrieval.
Microbial evolutionary strategies in a dynamic ocean
Authors: Walworth Nathan G. , Zakem Emily J. , Dunne John P. , Collins Sinéad , Levine Naomi M.
Published: March 2020

Marine microbes form the base of ocean food webs and drive ocean biogeochemical cycling. Yet little is known about the ability of microbial populations to adapt as they are advected through changing conditions. Here, we investigated the interplay between physical and biological timescales using a model of adaptation and an eddy-resolving ocean circulation climate model. Two criteria were identified that relate the timing and nature of adaptation to the ratio of physical to biological timescales. Genetic adaptation was impeded in highly variable regimes by nongenetic modifications but was promoted in more stable environments. An evolutionary trade-off emerged where greater short-term nongenetic transgenerational effects (low-γ strategy) enabled rapid responses to environmental fluctuations but delayed genetic adaptation, while fewer short-term transgenerational effects (high-γ strategy) allowed faster genetic adaptation but inhibited short-term responses. Our results demonstrate that the selective pressures for organisms within a single water mass vary based on differences in generation timescales resulting in different evolutionary strategies being favored. Organisms that experience more variable environments should favor a low-γ strategy. Furthermore, faster cell division rates should be a key factor in genetic adaptation in a changing ocean. Understanding and quantifying the relationship between evolutionary and physical timescales is critical for robust predictions of future microbial dynamics.
Embedded droplet printing in yield-stress fluids
Authors: Nelson Arif Z. , Kundukad Binu , Wong Wai Kuan , Khan Saif A. , Doyle Patrick S.
Published: March 2020

Microfluidic tools and techniques for manipulating fluid droplets have become core to many scientific and technological fields. Despite the plethora of existing approaches to fluidic manipulation, non-Newtonian fluid phenomena are rarely taken advantage of. Here we introduce embedded droplet printing—a system and methods for the generation, trapping, and processing of fluid droplets within yield-stress fluids, materials that exhibit extreme shear thinning. This technique allows for the manipulation of droplets under conditions that are simply unattainable with conventional microfluidic methods, namely the elimination of exterior influences including convection and solid boundaries. Because of this, we believe embedded droplet printing approaches an ideal for the experimentation, processing, or observation of many samples in an “absolutely quiescent” state, while also removing some troublesome aspects of microfluidics including the use of surfactants and the complexity of device manufacturing. We characterize a model material system to understand the process of droplet generation inside yield-stress fluids and develop a nascent set of archetypal operations that can be performed with embedded droplet printing. With these principles and tools, we demonstrate the benefits and versatility of our method, applying it toward the diverse applications of pharmaceutical crystallization, microbatch chemical reactions, and biological assays.
Regulation of stomatal development by stomatal lineage miRNAs
Authors: Zhu Jiali , Park Ji-Hwan , Lee Seulbee , Lee Jae Ho , Hwang Daehee , Kwak June M. , Kim Yun Ju
Published: March 2020

Stomata in the plant epidermis play a critical role in growth and survival by controlling gas exchange, transpiration, and immunity to pathogens. Plants modulate stomatal cell fate and patterning through key transcriptional factors and signaling pathways. MicroRNAs (miRNAs) are known to contribute to developmental plasticity in multicellular organisms; however, no miRNAs appear to target the known regulators of stomatal development. It remains unclear as to whether miRNAs are involved in stomatal development. Here, we report highly dynamic, developmentally stage-specific miRNA expression profiles from stomatal lineage cells. We demonstrate that stomatal lineage miRNAs positively and negatively regulate stomatal formation and patterning to avoid clustered stomata. Target prediction of stomatal lineage miRNAs implicates potential cellular processes in stomatal development. We show that miR399-mediatedPHO2regulation, involved in phosphate homeostasis, contributes to the control of stomatal development. Our study demonstrates that miRNAs constitute a critical component in the regulatory mechanisms controlling stomatal development.
SOX4-mediated repression of specific tRNAs inhibits proliferation of human glioblastoma cells
Authors: Yang Jianjing , Smith Derek K. , Ni Haoqi , Wu Ke , Huang Dongdong , Pan Sishi , Sathe Adwait A. , Tang Yu , Liu Meng-Lu , Xing Chao , Zhang Chun-Li , Zhuge Qichuan
Published: March 2020

Transfer RNAs (tRNAs) are products of RNA polymerase III (Pol III) and essential for mRNA translation and ultimately cell growth and proliferation. Whether and how individual tRNA genes are specifically regulated is not clear. Here, we report that SOX4, a well-known Pol II-dependent transcription factor that is critical for neurogenesis and reprogramming of somatic cells, also directly controls, unexpectedly, the expression of a subset of tRNA genes and therefore protein synthesis and proliferation of human glioblastoma cells. Genome-wide location analysis through chromatin immunoprecipitation-sequencing uncovers specific targeting of SOX4 to a subset of tRNA genes, including those for

tRNAi
Met

. Mechanistically, sequence-specific SOX4-binding impedes the recruitment of TATA box binding protein and Pol III to tRNA genes and thereby represses their expression. CRISPR/Cas9-mediated down-regulation of

tRNAi
Met

greatly inhibits growth and proliferation of human glioblastoma cells. Conversely, ectopic

tRNAi
Met

partially rescues SOX4-mediated repression of cell proliferation. Together, these results uncover a regulatory mode of individual tRNA genes to control cell behavior. Such regulation may coordinate codon usage and translation efficiency to meet the demands of diverse tissues and cell types, including cancer cells.
bioPROTACs as versatile modulators of intracellular therapeutic targets including proliferating cell nuclear antigen (PCNA)
Authors: Lim Shuhui , Khoo Regina , Peh Khong Ming , Teo Jinkai , Chang Shih Chieh , Ng Simon , Beilhartz Greg L. , Melnyk Roman A. , Johannes Charles W. , Brown Christopher J. , Lane David P. , Henry Brian , Partridge Anthony W.
Published: March 2020

Significance

Intracellular proteins interact with each other to perform functions that are critical to normal and disease states. Attempts at altering pathological protein–protein interactions with traditional approaches have largely failed. Here, we explore an emerging approach we call “bioPROTACs”—engineered fusion proteins that consist of a target binding domain and an E3 ligase, an arrangement that results in the specific degradation of the therapeutic target. Our systematic study shows bioPROTAC design requirements are highly flexible in terms of both the binding domain and E3 ligase components. Resulting molecules can be used as powerful tools for uncovering biology, informing on the design of small molecule target degraders (e.g. PROTACs), and, if delivery issues can be addressed, potential therapeutics.