bluuebunny/crossref_metadata_2025 huggingface dataset:
An injectable and self-healing hydrogel with covalent cross-linking in vivo for cranial bone repair
Authors: Lü Shaoyu , Bai Xiao , Liu Haidi , Ning Piao , Wang Zengqiang , Gao Chunmei , Ni Boli , Liu Mingzhu
Published: April 2017

DA click chemistry and dynamic acylhydrazone bond cross-linking are employed to obtain injectable and self-healing hydrogels for cranial bone repair.
N,S co-doped carbon dots as a stable bio-imaging probe for detection of intracellular temperature and tetracycline
Authors: Shi Weilong , Guo Feng , Han Mumei , Yuan Songliu , Guan Weisheng , Li Hao , Huang Hui , Liu Yang , Kang Zhenhui
Published: April 2017

N,S-CDs display an unambiguous bioimaging ability in the detection of intracellular temperature and tetracycline with satisfactory results.
Manipulating superconductivity of 1T-TiTe2by high pressure
Authors: Xiao R. C. , Lu W. J. , Shao D. F. , Li J. Y. , Wei M. J. , Lv H. Y. , Tong P. , Zhu X. B. , Sun Y. P.
Published: April 2017

Superconductivity of transition metal dichalcogenide 1T-TiTe2under high pressure was investigated by first-principles calculations.
PD_Manager: an mHealth platform for Parkinson's disease patient management
Authors: Tsiouris Kostas M. , Gatsios Dimitrios , Rigas George , Miljkovic Dragana , Koroušić Seljak Barbara , Bohanec Marko , Arredondo Maria T. , Antonini Angelo , Konitsiotis Spyros , Koutsouris Dimitrios D. , Fotiadis Dimitrios I.
Published: April 2017

PD_Manager is a mobile health platform designed to cover most of the aspects regarding the management of Parkinson's disease (PD) in a holistic approach. Patients are unobtrusively monitored using commercial wrist and insole sensors paired with a smartphone, to automatically estimate the severity of most of the PD motor symptoms. Besides motor symptoms monitoring, the patient's mobile application also provides various non‐motor self‐evaluation tests for assessing cognition, mood and nutrition to motivate them in becoming more active in managing their disease. All data from the mobile application and the sensors is transferred to a cloud infrastructure to allow easy access for clinicians and further processing. Clinicians can access this information using a separate mobile application that is specifically designed for their respective needs to provide faster and more accurate assessment of PD symptoms that facilitate patient evaluation. Machine learning techniques are used to estimate symptoms and disease progression trends to further enhance the provided information. The platform is also complemented with a decision support system (DSS) that notifies clinicians for the detection of new symptoms or the worsening of existing ones. As patient's symptoms are progressing, the DSS can also provide specific suggestions regarding appropriate medication changes.
Multilevel inverter with space vector modulation: intelligence direct torque control of induction motor
Authors: Kirankumar B. , Siva Reddy Y.V. , Vijayakumar M.
Published: April 2017

An Intelligence direct torque control (DTC) of induction motor using multilevel inverter with space vector modulation (SVM) is proposed in this study. The novelty of the proposed intelligence technique is an artificial neural network (ANN), which is utilised for the DTC of the induction motor. Here, ANN has been trained by using the target parameters such as reference quadrature and direct axis voltage with the corresponding input parameters change in motor torque and flux. The change in motor torque and flux parameters are identified by using the multilevel inverter output voltage and current. The back propagation process is used for the training process of the ANN. By using the ANN outputs, the SVM technique develops the control pulses for the multilevel inverter. Then the proposed intelligence technique is implemented in the MATLAB/simulink platform and the effectiveness is analysed by comparing with the different case studies and different methods. The comparison results demonstrate the superiority of the proposed approach and confirm its potential to solve the problem.
Research and realisation of reciprocal electronic circuits for gas ultrasonic flow meter
Authors: Zheng Dandan , Fu Xingyi , Yang Zhibin
Published: April 2017

The transit‐time ultrasonic flow meters often show non‐zero‐flow rate when the flow is stationary due to the variations between transducers, which results in a zero‐flow error. Moreover, the zero‐flow error may change along with the measurement environment which causes the zero‐drift error. The zero‐flow error and zero‐drift error will lead to false flow detection and influence the measurement stability at low velocities. Reciprocal operation theory has been proven to be an effective technique to eliminate zero‐flow error. Therefore, reciprocal electronic circuits for gas ultrasonic flow meter are designed in this study. The circuits are first modelled in PSpice to validate its effectiveness. It is shown that both the zero‐flow error and the zero drift are reduced significantly with the reciprocal circuits. Besides, the optimum matched resistor is determined by simulation. Second, three experiments are carried out to test the reciprocal circuits including transducers paired experiment, temperature test and flow calibration. Finally, it is verified that the reciprocal circuits can improve the measurement accuracy and stability for gas ultrasonic flow meter and the calibration results show that the gas ultrasonic flow meter (USM) with reciprocal circuits can achieve 1.0% measurement accuracy in 0.3–30 m/s.
N-Triflylphosphorimidoyl Trichloride: A Versatile Reagent for the Synthesis of Strong Chiral Brønsted Acids
Authors: List Benjamin , Lee Sunggi , Kaib Philip
Published: April 2017

A series of strong Brønsted acids has been synthesized in high yields using N-triflylphosphorimidoyl trichloride as reagent. The syntheses proceed efficiently with electron-rich, electron-deficient, and sterically hindered substrates.
FeCl3·6H2O-Catalyzed Tandem Alkylation–Hydrolysis Reaction of Chain α-Oxo Ketene Dithioacetals with Alcohols: Efficient ­Synthesis of α-Alkylated β-Oxo Thioesters
Authors: Yu Haifeng , Zhao Lijuan , Diao Quanping , Li Tiechun , Liao Peiqiu , Hou Dongyan , Xin Guang
Published: April 2017

A novel FeCl3·6H2O-catalyzed tandem Friedel–Crafts alkylation–hydrolysis reaction between chain α-oxo ketene dithioacetals and alcohols to afford α-alkylated β-oxo thioesters has been successfully developed. The reaction is efficient in the presence of catalyst loading as low as 30 mol% in MeCN at room temperature, and a wide variety of α-alkylated β-oxo thioesters are efficiently synthesized in good yields.
Catalytic Synthesis of Chiral Phosphole Oxides via Desymmetric C–H Arylation of o-Bromoaryl Phosphine Oxides
Authors: Cui Yu-Ming , Xu Li-Wen , Lin Yan , Ma Wei-Yang , Sun Qiao-Ying
Published: April 2017

A palladium-catalyzed intramolecular direct arylation reaction of o-bromoaryl phosphine oxides was developed to afford a variety of P-stereogenic phosphole oxides in good yields. The enantioselectivities were closely associated with the specific structures of substrates, which ranged from 4–94%. As a result of ready availability of starting materials and simple operation to improve the enantioselectivities of the products with low ee values, the method provides a simple and straightforward procedure for the synthesis of P-stereogenic phosphole oxides.
Surgeon-Reported Needs for Improved Training in Identifying and Managing Free Flap Compromise
Authors: McMillan Catherine , D'Hondt Veerle , Marshall Alexandra , Binhammer Paul , Lipa Joan , Snell Laura
Published: April 2017

Background This study examined the need for improved training in the identification and management of free flap (FF) compromise and assessed a potential role for simulated scenario training.

Methods Online needs assessment surveys were completed by plastic surgeons and a subsample with expertise in microsurgery education participated in focus groups. Data were analyzed using descriptive statistics and mixed qualitative methods.

Results In this study, 77 surgeons completed surveys and 11 experts participated in one of two focus groups. Forty-nine (64%) participants were educators, 65 and 45% of which reported having an insufficient volume of FF cases to adequately teach the management and identification of compromise, respectively. Forty-three percent of educators felt that graduating residents are not adequately prepared to manage FF compromise independently. Exposure to normal and abnormal FF cases was felt to be critical for effective training by focus group participants. Experts identified low failure rates, communication issues, and challenging teaching conditions as current barriers to training. Most educators (74%) felt that simulated scenario training would be “very useful” or “extremely useful” to current residents. Focus groups highlighted the need for a widely accepted algorithm for re-exploration and salvage on which to base the development of a training adjunct consisting of simulated scenarios.

Conclusion Trainee exposure to FF compromise is inadequate in existing plastic surgery programs. Early exposure, high case volume, and a standardized algorithmic approach to management with a focus on decision making may improve training. Simulated scenario training may be valuable in addressing current barriers.
Antral Follicles Count and Anti-Müllerian Hormone Levels after Gonadotoxic Chemotherapy in Patients with Breast Cancer: Cohort Study
Authors: Capp Edison , Corleta Helena von Eye , D'Avila Ângela Marcon
Published: April 2017

Aim To assess ovarian reserve (OVR) by means of follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), and antral follicle count (AFC) measurement in eumenorrheic women with breast cancer, exposed to gonadotoxic chemotherapy.

Method Fifty-two women (35.3 ± 3.8 years old) with breast cancer and undergoing cyclophosphamide-containing chemotherapy were enrolled. The assessment was performed before chemotherapy (T1) and after 2 (T2) and 6 months (T3).

Results Six months after chemotherapy, the prevalence of regular cycles was 60%. Anti-Müllerian hormone decreased down to undetectable levels at T2 and T3 (T1: 2.53 [1.00–5.31]; T2 < 0.08; T3: < 0.08 [< 0.08–1.07] ng/mL), (p < 0.0001). Antral follicle count was 11 [8.0–13.5] follicles at T1 and lower at T2 (5.50 [3.75–8.0] and T3 (5.0 [2.5–7.0]) (p < 0.0001). In patients who remained with regular cycles during chemotherapy or resumed normal menses, FSH and estradiol levels remained unchanged.

Conclusion Anti-Müllerian hormone and AFC are useful as markers of OVR decline in women exposed to chemotherapy. Follicle-stimulating hormone is only adequate in women who become amenorrheic.
Autosomal Recessive Primary Microcephaly (MCPH): An Update
Authors: Morris-Rosendahl Deborah , Kaindl Angela , Zaqout Sami
Published: April 2017

Autosomal recessive primary microcephaly (MCPH; MicroCephaly Primary Hereditary) is a genetically heterogeneous neurodevelopmental disorder characterized by a significantly reduced head circumference present already at birth and intellectual disability. Inconsistent features include hyperactivity, an expressive speech disorder, and epilepsy. Here, we provide a brief overview on this rare disorder pertinent for clinicians.
The Effect of Mesenchymal Stem Cells on Fertility in Experimental Retrocervical Endometriosis
Authors: Abreu Jaqueline Pedroso de , Rebelatto Carmen Lúcia Kuniyoshi , Savari Carolina Antunes , Capriglione Luiz Guilherme Achcar , Miyague Lye , Noronha Lucia de , Amaral Vivian Ferreira do
Published: April 2017

Purpose To evaluate the effect of mesenchymal stem cells (MSCs) on fertility in experimental retrocervical endometriosis.

Methods A total of 27 New Zealand rabbits were divided into three groups: endometriosis, in which endometrial implants were created; mesenchymal, in which MSCs were applied in addition to the creation of endometrial implants; and control, the group without endometriosis. Fisher's exact test was performed to compare the dichotomous qualitative variables among the groups. The quantitative variables were compared by the nonparametric Mann-Whitney and Kruskal-Wallis tests. The Mann-Whitney test was used for post-hoc multiple comparison with Boniferroni correction.

Results Regarding the beginning of the fertile period, the three groups had medians of 14 ± 12.7, 40 ± 5, and 33 ± 8.9 days respectively (p = 0.005). With regard to fertility (number of pregnancies), the endometriosis and control groups showed a rate of 77.78%, whereas the mesenchymal group showed a rate of 11.20% (p = 0.015). No differences in Keenan's histological classification were observed among the groups (p = 0.730). With regard to the macroscopic appearance of the lesions, the mesenchymal group showed the most pelvic adhesions.

Conclusion The use of MSCs in endometriosis negatively contributed to fertility, suggesting the role of these cells in the development of this disease.
Congenital Glioblastoma Multiforme: An Unusual and Challenging Tumor
Authors: Anestis Dimitrios , Ble Christina , Tsitouras Vassilios , Tsonidis Christos , Tsitsopoulos Parmenion
Published: April 2017

Congenital glioblastoma multiforme is a rare tumor of the central nervous system with unique features. The existing evidence on its pathogenesis, genetic and molecular profile, special characteristics, treatment, and prognosis is reviewed. An increased number of antenatal diagnoses and prolonged survival for those individuals who can tolerate combined surgical resection and chemotherapy has been noted. The overall prognosis, however, remains poor. A better understanding of this unusual entity is important. Further research is needed to discern tumor's pathogenesis and natural history. This will likely lead to the development and implementation of treatment strategies that may decrease mortality and morbidity in these patients.
Excited states from modified coupled cluster methods: Are they any better than EOM CCSD?
Authors: Rishi Varun , Perera Ajith , Nooijen Marcel , Bartlett Rodney J.
Published: April 2017

Simplifications or modifications of coupled cluster methods such as the CCSD (coupled cluster singles and doubles) model often perform better than the original method in providing the total energy, equilibrium geometries, and harmonic vibration frequencies for the ground state. Three such methods that have been recently proposed include 2CC, parameterized CCSD generalizations, and distinguishable cluster singles and doubles (DCSD) approach. In this paper, we lay the theoretical foundation needed to treat excited states via the equation of motion (EOM) approach using these ground state CC methods. As these ground state approximations to CCSD share its property of being exact for two-electron systems, so will their excited state extensions. These methods are tested for two complementary benchmark sets of excited states for a wide range of organic molecules with focus on singlet and triplet excited states of both valence and Rydberg nature. We also test these methods for doubly excited states, taking CH+ as an example to test their performance at equilibrium and stretched bond geometries. Finally, we assess if any of these methods perform consistently better than EOM CCSD.
Experimental scaling of plane-Born cross sections and ab initio assignments for electron-impact excitation and dissociation of XF4 (X = C, Si, and Ge) molecules
Authors: Hoshino M. , Duflot D. , Limão-Vieira P. , Ohtomi S. , Tanaka H.
Published: April 2017

Electron energy loss spectra of carbon tetrafluoride, silicon tetrafluoride, and germanium tetrafluoride molecules (CF4, SiF4, and GeF4) have been measured for incident electron energies of 50–360 eV at 1.5°–15.5° and for 30 eV and 30° scattering angle, while sweeping the energy loss over the range 9.0–20.0 eV. Low-lying valence excited triplet and singlet states are investigated by quantum chemical ab initio calculations. The Rydberg series converging to the (lowest) ionisation energy limits of XF4 (X = C, Si, Ge) are also identified and classified using the systematic behaviour according to the magnitude of the quantum defects. A generalized oscillator strength analysis is employed to derive oscillator strength f0 value and the apparent Born integral cross sections from the corresponding differential cross sections by using the Vriens formula for the optically allowed transitions. The f0 value is compared with the optical oscillator strength of the photoabsorption, pseudo-photon measurements, and theoretical values. The binary-encounter and f-scaled Born cross sections of the most intense optically allowed transitions have been also derived from the excitation threshold to the high energy region where the Born approximation is valid. Potential energy curves were obtained along the XF3 + F coordinate with two different basis sets to lend support on electron impact dissociation processes yielding radical formation. We found that in CF4, the lowest-lying dissociative character is due to intramolecular conversion from Rydberg 3s to valence character (σ*(C–F)), whereas in SiF4 and GeF4, an antibonding behaviour prevails.
Luminescence detection of nanoparticle inclusions from their phase transitions
Authors: Townsend P. D. , Finch A. A. , Maghrabi M. , Ramachandran V. , Vázquez G. V. , Wang Y. , White D. R.
Published: April 2017

Nanoparticle inclusions in insulators from contaminants dramatically alter host luminescence properties of intensity and spectra. Their presence is readily revealed if, during heating or cooling, the nanoparticles undergo phase transitions, as their structural changes modify the host signals. Examples cited include both bulk contaminants retained from growth, and impurities and changes from surface reactions and in-diffusion. Phase changes from impurities such as water ice, oxygen, nitrogen, argon, or carbon dioxide can alter the host emission intensity by factors of ten to a hundred times, and also distort the spectra. Such nanoparticle inclusions are detectable in many insulators. Unfortunately, not only does this imply that published data of luminescence performance efficiency may often have been compromised, but the examples of pressure transitions controlling long range interactions within the host lattice mean they distort not only luminescence signals, but also many electrical and other responses. Their relevance is thus unsuspected in a wide range of devices.
Inclusions in Si whiskers grown by Ni metal induced lateral crystallization
Authors: Radnóczi György Zoltán , Knez Daniel , Hofer Ferdinand , Frangis Nikolaos , Vouroutzis Nikolaos , Stoemenos John , Pécz Béla
Published: April 2017

The formation of Nickel-di-silicide inclusions in silicon whiskers grown during low temperature Ni Metal Induced Lateral Crystallization of amorphous Silicon was studied by High Resolution Transmission Electron Microscopy, Scanning Transmission Electron Microscopy, and Electron Energy Loss Spectroscopy. The heat treatment of the samples lasted for 11 + 11 days at 413 °C for the first 11 days and 442 °C for the rest of the time. The size of the inclusions ranges from just a few atoms to 15–20 nm. It was shown that the NiSi2 inclusions have the form of tetrahedrons, which are bound by {111} coherent interfaces with the Si matrix. These inclusions are homogeneously distributed along the whiskers, and the Ni percentage incorporated in these is 0.035 at. %. The tetrahedral inclusions are formed by trapping NiSi2 clusters at the Si/NiSi2 interface during whisker growth.
Linear and nonlinear stability of periodic orbits in annular billiards
Authors: Dettmann Carl P. , Fain Vitaly
Published: April 2017

An annular billiard is a dynamical system in which a particle moves freely in a disk except for elastic collisions with the boundary and also a circular scatterer in the interior of the disk. We investigate the stability properties of some periodic orbits in annular billiards in which the scatterer is touching or close to the boundary. We analytically show that there exist linearly stable periodic orbits of an arbitrary period for scatterers with decreasing radii that are located near the boundary of the disk. As the position of the scatterer moves away from a symmetry line of a periodic orbit, the stability of periodic orbits changes from elliptic to hyperbolic, corresponding to a saddle-center bifurcation. When the scatterer is tangent to the boundary, the periodic orbit is parabolic. We prove that slightly changing the reflection angle of the orbit in the tangential situation leads to the existence of Kolmogorov-Arnold-Moser islands. Thus, we show that there exists a decreasing to zero sequence of open intervals of scatterer radii, along which the billiard table is not ergodic.
Effect of heat capacity on monthly and yearly exergy performance of building integrated semitransparent photovoltaic thermal system
Authors: Gupta Neha , Tiwari G. N.
Published: April 2017

In this communication, a building integrated semitransparent photovoltaic thermal (BiSPVT) system has been analysed, in which the effect of heat capacity has been studied by placing a water tank inside the room. The water tank helps in achieving better thermal comfort conditions. An analytical expression for water temperature, tank temperature, room air temperature, floor temperature, and the solar cell temperature of the BiSPVT system has been derived to evaluate the thermal load levelling (TLL), monthly thermal exergy, and yearly overall exergy, including natural day lighting. Numerical computations have been carried out for cold climatic conditions of Srinagar, India. Based on computations, the following conclusions have been drawn: The TLL decreases with an increase in the heat capacity (from 0 to 600 kg) by 20.39%. The exergy is minimum in December and maximum in June for all heat capacities of water mass. The thermal energy and electrical energy are the lowest in January. The electrical efficiency decreases by 8.3% with an increase in the water mass from 0 to 600 kg in January, and the average monthly thermal exergy and yearly overall exergy increase with an increase in the heat capacity of water mass.
Cold wire constant voltage anemometry to measure temperature fluctuations and its application in a thermoacoustic system
Authors: Cleve Sarah , Jondeau Emmanuel , Blanc-Benon Philippe , Comte-Bellot Geneviève
Published: April 2017

The knowledge of temperature fluctuations is essential for most thermoacoustic systems. In the present paper, cold wire constant-voltage anemometry (CVA) to measure temperature fluctuations is presented. Corrections for the thermal inertia and for the end losses of the wire are applied during the post-processing. The correction for the thermal inertia of the cold wire is achieved by applying a time dependent thermal lag as proposed originally for a constant-current anemometry (CCA) system. This thermal lag is measured in parallel by a hot wire. The thermal end losses of the wires to their supports are also considered and approximate corrections are proposed. The procedure for the cold wire CVA is validated in the acoustic field of an acoustic resonator with wires of different lengths. A comparison between a CVA and a CCA measurement also confirms the CVA measurement. Furthermore, the proposed measurement procedure is applied close to the stack of a thermoacoustic refrigerator. Supposing a two-dimensional flow, the simultaneous measurement of velocity and temperature fluctuations is possible. This allows a detailed examination of the acoustic field close to the stack, including the study of the correlation between temperature and velocity.
Two-dimensional simulation of argon dielectric barrier discharge excited by a Gaussian voltage at atmospheric pressure
Authors: Xu Yonggang , Wang Jing , Li Jing , Lei Bingying , Tang Jie , Wang Yishan , Li Yongfang , Zhao Wei , Duan Yixiang
Published: April 2017

A two-dimensional self-consistent fluid model was employed to investigate the spatiotemporal characteristics of discharges in atmospheric pressure argon (Ar) dielectric barrier discharge driven by a Gaussian voltage. The simulation results show that a discharge with multiple current pulses occurs each half-cycle in the gas gap. A transition from the Townsend mode to the glow mode is observed with the increasing applied voltage each half-cycle at a lower driving frequency (7.5 kHz). It is also found that the glow mode survives all the discharge phases at a higher driving frequency (12.5 kHz and 40 kHz). The change in the discharge mode with the driving frequency mainly lies in the fact that a lot of charged particles created in the discharge gap have no enough time to drift and diffuse around, and then these particles are assembled in the discharge space at higher frequency. Additionally, the spatial distributions of the electron density indicate that a center-advantage discharge is ignited at the driving frequencies of interest, resulting in the radial non-uniformity of discharge because of the edge effects. However, this overall non-uniformity is weakened with the driving frequency increased to 40 kHz, at which concentric ring patterns are observed. These distinct behaviors are mainly attributed to the fact that many charged particles generated are trapped in the gas gap and then accumulated to make the extension along the radial direction due to the charged particles transport and diffusion, and that the effective overlapping of a large number of avalanches induced by the increased “seed” electron density with the driving frequency. Meanwhile, the surface charged particles accumulated on the dielectric barriers are also shown to play a role in the formation of the discharge structure.
Improved design for a low temperature scanning tunneling microscope with an in situ tip treatment stage
Authors: Kim J.-J. , Joo S. H. , Lee K. S. , Yoo J. H. , Park M. S. , Kwak J. S. , Lee Jinho
Published: April 2017

The Low Temperature Scanning Tunneling Microscope (LT-STM) is an extremely valuable tool not only in surface science but also in condensed matter physics. For years, numerous new ideas have been adopted to perfect LT-STM performances—Ultra-Low Vibration (ULV) laboratory and the rigid STM head design are among them. Here, we present three improvements for the design of the ULV laboratory and the LT-STM: tip treatment stage, sample cleaving stage, and vibration isolation system. The improved tip treatment stage enables us to perform field emission for the purpose of tip treatment in situ without exchanging samples, while our enhanced sample cleaving stage allows us to cleave samples at low temperature in a vacuum without optical access by a simple pressing motion. Our newly designed vibration isolation system provides efficient space usage while maintaining vibration isolation capability. These improvements enhance the quality of spectroscopic imaging experiments that can last for many days and provide increased data yield, which we expect can be indispensable elements in future LT-STM designs.
Tailoring the functional properties of PLZT-BaTiO3 composite ceramics by core-shell approach
Authors: Curecheriu Lavinia-Petronela , Buscaglia Maria Teresa , Maglia Filippo , Padurariu Cipriana , Ciobanu Gabriela , Anselmi-Tamburini Umberto , Buscaglia Vincenzo , Mitoseriu Liliana
Published: April 2017

In the present work, composite ceramics of BaTiO3 with La0.08Pb0.92Ti0.20Zr0.80O3 were prepared from powders synthesized by two different methods: (a) PLZT@BT ceramics from core-shell powders with PLZT-core and BaTiO3 shell and (b) PLZT-BT ceramic composites from mixed PLZT and BaTiO3 powders. In core-shell ceramics, a thin conductive layer of BaPbO3 was formed that resulted in an increased effective permittivity with relatively low losses (tan δ < 0.7 in kHz regions). The extrinsic contributions play an important role in both ceramics, but they are more evident in core-shell samples due to the large number of interfaces. These results show that novel functional properties can be tailored by the controlled chemical reaction at interfaces.
Simulation of the target creation through FRC merging for a magneto-inertial fusion concept
Authors: Li Chenguang , Yang Xianjun
Published: April 2017

A two-dimensional magnetohydrodynamics model has been used to simulate the target creation process in a magneto-inertial fusion concept named Magnetized Plasma Fusion Reactor (MPFR) [C. Li and X. Yang, Phys. Plasmas 23, 102702 (2016)], where the target plasma created through Field reversed configuration (FRC) merging was compressed by an imploding liner driven by the pulsed-power driver. In the scheme, two initial FRCs (Field reversed configurations) are translated into the region where FRC merging occurs, bringing out the target plasma ready for compression. The simulations cover the three stages of the target creation process: formation, translation, and merging. The factors affecting the achieved target are analyzed numerically. The magnetic field gradient produced by the conical coils is found to determine how fast the FRC is accelerated to peak velocity and the collision merging occurs. Moreover, it is demonstrated that FRC merging can be realized by real coils with gaps showing nearly identical performance, and the optimized target by FRC merging shows larger internal energy and retained flux, which is more suitable for the MPFR concept.
Thermodynamic properties of liquid sodium under high pressure
Authors: Li Huaming , Zhang Xiaoxiao , Sun Yongli , Li Mo
Published: April 2017

Acquiring reliable thermodynamic properties in liquid metals at high pressure and temperature is still a challenge in both experiment and theory. Equation of state (EoS) offers an alternative approach free of many of the difficulties. Here using the EoS of a power law form we obtained the thermodynamic properties of liquid sodium under pressure along the isothermal lines, including isothermal buck modulus, thermal expansion coefficient, Grüneisen parameter, and Anderson-Grüneisen parameter. The results are in excellent agreement with available experimental data measured by a piezometer at high temperature and high pressure and sound velocity measurement with pulse-echo technique. We found that the pressure derivative of the isothermal bulk modulus at zero pressure is a monotonic function of temperature and has a value around 4. In addition, unexpected crossing points were found in the isobaric thermal expansion coefficient and Grüneisen parameter; and a minimum in the isobaric heat under isothermal compression was also observed. While some of these detailed predictions are yet to be confirmed by further experiment, our results suggest that the power law form may be a more suitable choice for the EoS of liquids metals.
Impact of organic overlayers on a-Si:H/c-Si surface potential
Authors: Seif Johannes P. , Niesen Bjoern , Tomasi Andrea , Ballif Christophe , De Wolf Stefaan
Published: April 2017

Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.
Electronic structure of CdSe-ZnS 2D nanoplatelets
Authors: Cruguel Hervé , Livache Clément , Martinez Bertille , Pedetti Silvia , Pierucci Debora , Izquierdo Eva , Dufour Marion , Ithurria Sandrine , Aubin Hervé , Ouerghi Abdelkarim , Lacaze Emmanuelle , Silly Mathieu G. , Dubertret Benoit , Lhuillier Emmanuel
Published: April 2017

Among colloidal nanocrystals, 2D nanoplatelets (NPLs) made of cadmium chalcogenides have led to especially well controlled optical features. However, the growth of core shell heterostructures has so far been mostly focused on CdS shells, while more confined materials will be more promising to decouple the emitting quantum states of the core from their external environment. Using k·p simulation, we demonstrate that a ZnS shell reduces by a factor 10 the leakage of the wavefunction into the surrounding medium. Using X-ray photoemission (XPS), we confirm that the CdSe active layer is indeed unoxidized. Finally, we build an effective electronic spectrum for these CdSe/ZnS NPLs on an absolute energy scale which is a critical set of parameters for the future integration of this material into optoelectronic devices. We determine the work function (WF) to be 4.47 eV while the material is behaving as an n-type semiconductor.
Compensating group delay distortion of signals based on engineered material dispersion
Authors: Wang Chun , Zhu Zhongbo , Cao Cheng , Qiao Shan , Li Changzhi , Ye Dexin
Published: April 2017

Dispersion, which originates from the total frequency responses of materials, devices and transmission lines, makes envelope distortion of signals inevitable in transmission systems. In this study, we investigate the group delay distortion of a signal due to the presence of dispersion in transmission systems, and propose an approach to eliminate the distortion by compensation based on engineered material dispersion. We demonstrate theoretically and experimentally that utilizing the anomalous frequency response of a dispersive material, envelope distortion of a signal passing through a given transmission system can be fully compensated. Compared with previous researches on dispersion compensation using grating compressors or chirp compressors in optics and non-Foster circuits in microwave bands, the proposed approach is robust and scalable to other frequency bands.
Suppressing double-metal-surface resonant multipactor by three dimensional wavy surface
Authors: Chang C. , Li Y. D. , Verboncoeur J. , Liu Y. S. , Liu C. L.
Published: April 2017

Here, a method to suppress resonant multipaction in microwave systems is proposed in which the radio frequency system's metal plates are patterned with a three-dimensional periodic ripple profile in which each unit is two orders smaller than the radio frequency wavelength. The multipaction-inhibiting mechanism was studied analytically and with a particle-in-cell simulation. The analytical and three-dimensional electromagnetic simulated field distribution of the rotationally symmetric surface structures shows the evanescent E-field characteristics in the ripple valleys, which increase the electron staid time and the temporal dispersion of the secondary electron generation, as well as causing the electrons to deviate from the resonant phase that causes multipaction.
Effect of biochar, zeolite and bentonite feed supplements on egg yield and excreta attributes
Authors: Prasai T. P. , Walsh K. B. , Midmore D. J. , Bhattarai S. P.
Published: April 2017

Bond Brown Layer (BBL) pullets (n = 200, 18 weeks old) were randomly assigned to 10 dietary treatments involving biochar, zeolite and bentonite at nil, 1%, 2%, and 4% w/w supplementation of commercial layer feed. Each treatment was applied to four cages, with five birds per cage, a total of 20 birds per treatment. Birds were maintained on these diets for 25 weeks. Feed conversion ratio was significantly improved (P = 0.001) with biochar-supplemented feed compared with the control and other treatments. Average egg weight was also significantly improved in the treatment groups compared with the control; however, shell weight, shell breaking strength, shell thickness, shell deformation and shell reflectivity, and internal egg-quality traits of albumen height and Haugh unit were not consistently different (P > 0.05). Yolk colour score was decreased significantly (P = 0.001) with the use of increased rate of additives. Intestinal villi height and crypt depth were increased on amended diets. Egg yield was decreased when birds were placed on a fungal contaminated feed. The feed amendments ameliorated this effect, with the best result achieved on a 2% biochar diet. Improved egg production was also noted under commercial certified organic production conditions trialling 2% biochar feed supplementation compared with the control. Thus, supplementation of feed with biochar, zeolite and bentonite improved production performance traits of egg yield and feed conversion ratio, with these additives potentially acting as detoxifiers or inhibiting growth of microbial pathogens, slowing digestion or altering the gut anatomy and microbiota to improve feed conversion ratio.
Recent Developments on Ultrasound-Assisted Synthesis of Bioactive N-Heterocycles at Ambient Temperature
Authors: Banerjee Bubun
Published: April 2017

N-Heterocycles represent privileged structural subunits well distributed in naturally occurring compounds with immense biological activities. The last decade has seen a tremendous practice to carry out reactions at ambient temperature avoiding harsh reaction conditions. By applying ultrasonic radiation in organic synthesis we can make synthetic protocols more sustainable and can carry out reactions at room temperature avoiding the traditional thermal harsh reaction conditions. Therefore the synthesis of biologically relevant N-heterocycles at room temperature under the influence of ultrasonic irradiation is one of the advancing areas in the 21st century among organic chemists. The present review summarises the latest developments on ultrasound-assisted synthesis of biologically relevant N-heterocycles at ambient temperature.
Subduction zone forearc serpentinites as incubators for deep microbial life
Authors: Plümper Oliver , King Helen E. , Geisler Thorsten , Liu Yang , Pabst Sonja , Savov Ivan P. , Rost Detlef , Zack Thomas
Published: April 2017

Significance

We document organic matter encapsulated in rock clasts from a oceanic serpentinite mud volcano above the Izu–Bonin–Mariana subduction zone (Pacific Ocean). Although we cannot pinpoint the exact origin of the organic matter, chemical analysis of the constituents resembles molecular signatures that could be produced by microbial life deep within or below the mud volcano. Considering the known temperature limit for life, 122 °C, and the subduction zone forearc geotherm where such mud volcanoes are located, we estimate that life could exist as deep as ∼10,000 m below the seafloor. This is considerably deeper than other active serpentinizing regions such as midocean ridges and could have provided sheltered ecosystems for life to survive the more violent phases of Earth’s history.
Increasing honesty in humans with noninvasive brain stimulation
Authors: Maréchal Michel André , Cohn Alain , Ugazio Giuseppe , Ruff Christian C.
Published: April 2017

Significance

Honesty affects almost every aspect of social and economic life. We conducted experiments in which participants could earn considerable amounts of money by cheating on a die-rolling task. Cheating was substantial but decreased by more than one-half during transcranial direct current stimulation over the right dorsolateral prefrontal cortex. This stimulation-induced increase in honesty was functionally specific: It did not affect other types of behavioral control related to self-interest, risk-taking, and impulsivity. Moreover, cheating was only reduced when it benefited the participants themselves rather than another person. Thus, the human brain implements specialized processes that enable us to remain honest when faced with opportunities to cheat for personal material gain. Importantly, these processes can be strengthened by external interventions.
Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision
Authors: Greenwood John A. , Szinte Martin , Sayim Bilge , Cavanagh Patrick
Published: April 2017

Significance

Our ability to see, localize, and interact with stimuli varies depending on their location in the visual field. Here we consider the source of these variations for several aspects of spatial vision: crowding (the disruption of object recognition in clutter), spatial localization, and saccadic eye movements. We observe a range of variations across both individuals and the visual field with strong correlations between all tasks. However, a number of dissociations exclude the possibility that these correlations arise from the same spatial representation of the visual field. Rather, we propose a “topology of spatial vision,” whereby idiosyncratic variations in spatial precision are established early in the visual system and inherited up to the highest levels of object recognition and motor planning.
APC/C
Cdh1
-Rock2 pathway controls dendritic integrity and memory
Authors: Bobo-Jiménez Verónica , Delgado-Esteban María , Angibaud Julie , Sánchez-Morán Irene , de la Fuente Antonio , Yajeya Javier , Nägerl U. Valentin , Castillo José , Bolaños Juan P. , Almeida Angeles
Published: April 2017

Significance

Disruption of neuronal dendrites causes cognitive impairment in Alzheimer’s disease (AD). Rock2, a kinase of the Rho family of proteins, is a dendrite destabilizer that accumulates in the AD brain. However, why Rock2 aberrantly aggregates, causing neuronal integrity loss, is unknown. Here, we show that Rock2 protein stability is controlled by the ubiquitin ligase APC/C
Cdh1
. Accordingly, APC/C
Cdh1
loss of function in adult neurons increases Rock2 protein and activity, causing dendrite disruption in the cortex and hippocampus, along with memory loss and neurodegeneration, in mice. These effects are abolished by inhibition of Rock2 activity. Thus, the APC/C
Cdh1
-Rock2 pathway may be a novel therapeutic target against neurodegeneration.
Structural hierarchy controlling dimerization and target DNA recognition in the AHR transcriptional complex
Authors: Seok Seung-Hyeon , Lee Woojong , Jiang Li , Molugu Kaivalya , Zheng Aiping , Li Yitong , Park Sanghyun , Bradfield Christopher A. , Xing Yongna
Published: April 2017

Significance

The aryl hydrocarbon receptor (AHR) is unique among PAS family transcription factors in its diverse environmental and cellular ligands and broad array of biological endpoints. AHR dimerizes with AHR nuclear translocator (ARNT) and subsequently interacts with genomic enhancers, dioxin response elements (DREs). Our crystal structure of the AHR–ARNT heterodimer in complex with DRE provides structural insights into this transcriptional complex. Our studies reveal three-dimensional structural codes for specific engagement of DRE that discriminates it from the closely related hypoxia response elements; the highly intertwined dimerization and interdomain interfaces remotely control DRE-binding and ligand-induced exposure of nuclear localization signal. The structural similarity and ramifications of the AHR, HIF, and NPAS transcriptional complexes with ARNT provide general and unique insights into PAS family transcription factors and complex AHR signaling.
El Niño and the shifting geography of cholera in Africa
Authors: Moore Sean M. , Azman Andrew S. , Zaitchik Benjamin F. , Mintz Eric D. , Brunkard Joan , Legros Dominique , Hill Alexandra , McKay Heather , Luquero Francisco J. , Olson David , Lessler Justin
Published: April 2017

Significance

In the wake of the 2015–2016 El Niño, multiple cholera epidemics occurred in East Africa, including the largest outbreak since the 1997–1998 El Niño in Tanzania, suggesting a link between El Niño and cholera in Africa. However, little evidence exists for this link. Using high-resolution mapping techniques, we found the cholera burden shifts to East Africa during and following El Niño events. Throughout Africa, cholera incidence increased three-fold in El Niño-sensitive regions, and 177 million people experienced an increase in cholera incidence. Without treatment, the case fatality rate can reach 50%, but accessible, appropriate care nearly eliminates mortality. Climatic forecasts predicting El Niño events 6–12 mo in advance could trigger public health preparations and save lives.
Dimerization of Tie2 mediated by its membrane-proximal FNIII domains
Authors: Moore Jason O. , Lemmon Mark A. , Ferguson Kathryn M.
Published: April 2017

Significance

Tie2 is a receptor tyrosine kinase with important roles in vascular development. Inhibiting Tie2 may impair tumor angiogenesis, whereas activating Tie2 may be beneficial in sepsis and inflammation. To modulate Tie2 therapeutically, it is essential to understand its regulation. Although it is known how Tie2 binds its activating ligands (angiopoietins), it is not clear how this binding (or Tie1 interactions) regulates the receptor. Here, we show that the previously unstudied Tie2 extracellular membrane-proximal region engages in receptor–receptor contacts crucial for Tie2 activation. Our data suggest that angiopoietins promote receptor clustering, utilizing Tie2–Tie2 interactions mediated by key fibronectin III domains, a unique mode of RTK activation. Blocking these Tie2–Tie2 interactions may have therapeutic value in cancer.
Floodplains as an Achilles’ heel of Amazonian forest resilience
Authors: Flores Bernardo M. , Holmgren Milena , Xu Chi , van Nes Egbert H. , Jakovac Catarina C. , Mesquita Rita C. G. , Scheffer Marten
Published: April 2017

Significance

Climate change may alter the distribution of biomes in tropical regions with implications for biodiversity and ecosystem services. Here we reveal that if the Amazon region becomes drier as predicted, forests may collapse first on seasonally inundated areas due to their vulnerability to wildfires. The widespread distribution of floodplain forests at the western and central regions implies that fire-prone savannas may expand deep into this massive forest biome, threatening the resilience of the entire system. Our findings suggest the need for a strategic fire management plan to strengthen Amazonian forest resilience in the face of climate change.
Context-dependent spatially periodic activity in the human entorhinal cortex
Authors: Nadasdy Zoltan , Nguyen T. Peter , Török Ágoston , Shen Jason Y. , Briggs Deborah E. , Modur Pradeep N. , Buchanan Robert J.
Published: April 2017

Significance

In the mammalian brain, neurons in the hippocampus represent unique places and neurons in the entorhinal cortex, so-called grid cells, provide an internal coordinate system of the environment. Dysfunction in this circuit causes memory problems and disorientation, which are early symptoms of Alzheimer’s disease. Much of what we have learned from this circuit is based on rodent studies. Here, we report that grid cells in the human brain represent space in a more environmentally adaptive manner than in rodents. Human grids show an increased scalability with the environment relative to rodents. The enhanced context dependency of spatial representations is probably a late development of evolution.
Universal modal radiation laws for all thermal emitters
Authors: Miller David A. B. , Zhu Linxiao , Fan Shanhui
Published: April 2017

Significance

Radiation laws must relate the fraction of incident radiation absorbed by an object and the amount of radiation emitted when it is hot so that objects can come to the same temperature just by exchanging electromagnetic radiation. Such laws are fundamentally important and set limits to practical applications such as in the conversion of light to electricity and in heat and thermal management generally. Kirchhoff’s classic results work well in many situations, but fail in others (specifically for “nonreciprocal” materials), and were derived using simplified models that do not apply to modern nanotechnology and light beams. We derive revised versions of laws that avoid these problems and discover additional and unexpected radiation laws that substantially expand the fundamental relations between optical absorption and emission.