bluuebunny/crossref_metadata_2025 huggingface dataset:
A C1-symmetric N-heterocyclic carbene catalysed oxidative spiroannulation of isatin-derived enals: highly enantioselective synthesis of spirooxindole δ-lactones
Authors: Lin Jun-Bing , Cheng Xi-Na , Tian Xiao-Dong , Xu Guo-Qiang , Luo Yong-Chun , Xu Peng-Fei
Published: April 2018

A NHC-catalysed spiroannulation of isatin-derived enals and 1,3-dicarbonyl compounds has been developed, enabling enantioselective synthesis of synthetically important spirooxindole δ-lactones.
Silver nanoparticle-loaded microgel-based etalons for H2O2sensing
Authors: Shu Tong , Shen Qiming , Wan Yu , Zhang Wei , Su Lei , Zhang Xueji , Serpe Michael J.
Published: April 2018

Silver nanoparticle (AgNP)-loaded poly(N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc)-based microgels were generated and used to make etalons. The etalons were shown to exhibit optical properties that depended on the concentration of H2O2in solution.
Red-emissive azabenzanthrone derivatives for photodynamic therapy irradiated with ultralow light power density and two-photon imaging
Authors: Zang Qiguang , Yu Jiayi , Yu Wenbin , Qian Jun , Hu Rongrong , Tang Ben Zhong
Published: April 2018

Azabenzanthrone derivatives with high phototoxicity and efficient emission are designed for photodynamic therapy and deep-tissue imaging.
Recent advances in near-infrared II fluorophores for multifunctional biomedical imaging
Authors: Ding Feng , Zhan Yibei , Lu Xiaoju , Sun Yao
Published: April 2018

A review of recent advances in near-infrared II fluorophores for multifunctional biomedical imaging.
Chemical structure and bonding in a thorium(iii)–aluminum heterobimetallic complex
Authors: Altman Alison B. , Brown Alexandra C. , Rao Guodong , Lohrey Trevor D. , Britt R. David , Maron Laurent , Minasian Stefan G. , Shuh David K. , Arnold John
Published: April 2018

We describe the syntheses of [Th(iii)]–[Al] and [U(iii)]–[Al] bimetallics that demonstrate An→Al interactions where the actinide behaves as an electron donor.
Nanoparticle adsorption dynamics at fluid interfaces
Authors: Hua Xiaoqing , Frechette Joelle , Bevan Michael A.
Published: April 2018

Measurements and models of nanoparticle adsorption dynamics at fluid interfaces are used to understand how transport and interactions together determine dynamic interfacial properties.
Electrostatic interactions in soft particle systems: mesoscale simulations of ionic liquids
Authors: Wang Yong-Lei , Zhu You-Liang , Lu Zhong-Yuan , Laaksonen Aatto
Published: April 2018

Computer simulations provide a unique insight into the microscopic details, molecular interactions and dynamic behavior responsible for many distinct physicochemical properties of ionic liquids.
Nb-doped amorphous titanium oxide compact layer for formamidinium-based high efficiency perovskite solar cells by low-temperature fabrication
Authors: Numata Youhei , Ishikawa Ryo , Sanehira Yoshitaka , Kogo Atsushi , Shirai Hajime , Miyasaka Tsutomu
Published: April 2018

Low-temperature processed perovskite solar cells (PSCs) were prepared using an amorphous niobium-doped titanium oxide (Nb/TiOx) film as a compact layer (CL) combined with a brookite TiO2 mesoporous layer.
Layer-to-layer distance determines the performance of 3D bio-electrochemical lamellar anodes in microbial energy transduction processes
Authors: Massazza Diego , Busalmen Juan P. , Parra Rodrigo , Romeo Hernán E.
Published: April 2018

Layer-to-layer distance determines the performance of 3D lamellar bio-anodes. Contrary to the widespread belief, electrodes with the highest surface area per unit volume (shorter interlayer distances) do not render maximum current densities. This is because the amount of colonizing bacteria does not scale linearly to the electrode surface area.
Nano-SiO2-embedded poly(propylene carbonate)-based composite gel polymer electrolyte for lithium–sulfur batteries
Authors: Huang Huijia , Ding Fei , Zhong Hai , Li Huan , Zhang Weiguo , Liu Xingjiang , Xu Qiang
Published: April 2018

All-solid-state electrochemical energy storage devices are highly in demand for future energy storage, where quasi-solid-state systems, such as gel polymer electrolytes, represent an important step towards this goal.
Discovery of cobweb-like MoC6 and its application for nitrogen fixation
Authors: Chen Z. W. , Lang X. Y. , Jiang Q.
Published: April 2018

A new 2D MoC6 is discovered as a nitrogen reduction reaction electrocatalyst with a quite low potential of −0.54 V.
The effects of surface charge on the intra-tumor penetration of drug delivery vehicles with tumor progression
Authors: Han Donglin , Qi Hongzhao , Huang Kai , Li Xueping , Zhan Qi , Zhao Jin , Hou Xin , Yang Xianjin , Kang Chunsheng , Yuan Xubo
Published: April 2018

Tumor progression determines the penetrating ability of drug delivery vehicles with different surface charges.
Timely coordinated phototherapy mediated by mesoporous organosilica coated triangular gold nanoprisms
Authors: Liu Wenfei , Tian Ying , Zhang Yunlei , Liu Kai , Zhao Shuang , Zhang Junjie , Su Yunyan , Zhao Ying , Tang Yuxia , Sun Jing , Tian Wei , Song Liang , Teng Zhaogang , Wang Shouju , Lu Guangming
Published: April 2018

Mesoporous organosilica coated triangular gold nanoprisms for timely coordinated phototherapy.
Improved multi‐scale line detection method for retinal blood vessel segmentation
Authors: Yue Kejuan , Zou Beiji , Chen Zailiang , Liu Qing
Published: April 2018

Changes of retinal blood vessel are precursors of many serious diseases such as diabetic retinopathy, hypertension and cardiovascular diseases. Automatic segmentation of retinal blood vessels in the fundus image can better assist in the diagnosis of these diseases and has been studied by many researchers. However, the segmentation of pale vessel pixels remains a problem because of their low contrasts with surrounding pixels. This study proposes an improved multi‐scale line detector to segment retinal vessels. It computes the line responses of vessels in multi‐scale windows and takes the maximum as the response value, which can enhance the responses of pale vessel pixels near strong vessels or dark background pixels. Experimental results on the publicly available database DRIVE demonstrate that the proposed method can detect pale vessel pixels better. It achieves 75.28% in sensitivity and 94.47% in accuracy, which outperforms the state‐of‐the‐art unsupervised methods. Compared with the supervised methods it also gets better sensitivity and comparable accuracy.
MS‐routing‐Gi: routing technique to minimise energy consumption and packet loss in WSNs with mobile sink
Authors: El Alami Hassan , Najid Abdellah
Published: April 2018

Energy efficiency is a major factor in designing wireless sensor networks (WSNs). Clustering design and grid‐based scheme are one of the techniques to save energy in WSNs. However, for a mobile sink in WSNs, packet loss rate that occurs due to the sink mobility is also a significant challenge. Here, an enhanced routing‐Gi protocol for a mobile sink in WSNs has been proposed to not only enhance energy efficiency but also minimise the packet loss rate. Simulation results show that the proposed protocol is more efficient than the previous protocols in terms of the network lifespan, energy efficiency, and packet delivery ratio. Thus, the proposed approach in this work could further be adapted to investigate highly mobility of sink in WSNs.
Efficient online/offline IBSS protocol using partial discrete logarithm for WSNs
Authors: Meshram Chandrashekhar , Powar Pournima L. , Obaidat Mohammad S. , Lee Cheng‐Chi , Meshram Sarita Gajbhiye
Published: April 2018

An online/offline identity‐based short signature (IBSS) protocol permits the signer to produce an online IBSS in real time from a precomputed offline IBSS when given a record. Such techniques are especially valuable in resource‐constrained wireless sensor network (WSN) applications. Recently, Meshram et al. presented an UF‐IBSS‐CMA‐protected online/offline IBSS protocol using partial discrete logarithm. In this study, the authors propose an extension of Meshram et al. scheme and compare with other IBSS protocols. The presented offline signing process does not want any private data from the signer. Henceforth, it can be created by any reliable outsider with the private key generation (PKG). This is especially valuable as the base station for a WSN node, performing as a PKG, can produce the offline data and the node does not have to come back to the base station for the re‐establishment of the offline data each time signing is implemented. Also, they demonstrate how the scheme can be extended to allow a single user to sign multiple messages and its implementation on WSN.
Efficiency optimisation of ZVS isolated bidirectional DAB converters
Authors: Dung Nguyen Anh , Chiu Huang‐Jen , Lin Jing‐Yuan , Hsieh Yao‐Ching , Liu Yu‐Chen
Published: April 2018

This study presents a control method for isolated bidirectional dual‐active‐bridge converters to optimise the efficiency by achieving the zero‐voltage switching (ZVS) in high‐voltage applications, which the switching losses are the major issues. At light‐load condition, the duty control algorithm is proposed to achieve the ZVS for all switches while the triple phase shift with ZVS condition is realised at heavy load condition. The operating principles and the design considerations of the proposed control scheme are analysed in detail. A 2 kW prototype converter is built up and tested to verify the feasibility of the proposed control strategy.
Family of isolated bidirectional resonant converters with duty‐cycle control and automatic power flow transition
Authors: Zheng Yifei , Li Shouxiang , Dey Swatilekha , Smedley Keyue
Published: April 2018

This study proposes a family of duty‐cycle controlled bidirectional resonant converters and its uniform modulation schemes. This family of converters is composed of a current‐fed stage, a transformer with LC resonant tank and a voltage‐fed stage. Therefore, high‐voltage gain and low‐current ripple can be achieved. With the proposed uniform modulation schemes, automatic forward and backward mode transition is realised. Furthermore, the voltage gain is only determined by the duty cycle, independent of load and power flow direction, thus simple control can be adopted and voltage can be regulated in a wide range. Zero‐voltage switching of all switches can be achieved over a wide load range. The operation principle and analysis of one of the converters are presented as an example. Design considerations are provided. Experimental results are shown to verify the theoretical analysis.
Optimal integration of MBESSs/SBESSs in distribution systems with renewables
Authors: Zheng Yu , Meng Ke , Luo Fengji , Qiu Jing , Zhao Junhua
Published: April 2018

The net demand of distribution systems of renewable energy shows strong daily and seasonal patterns that may cause a loss of operation and constriction. Battery energy storage systems (BESS) allow peak load shaving and are used to enhance the reliability of distribution systems. In addition to the problem of an unbalanced net demand, there can be significant net demand fluctuation for different times and locations. To address this, mobile BESS (MBESS) can offer advantages over static BESS (SBESS) in operation flexibility, though may require higher engineering costs. In this study, an operation model was proposed to coordinate static and MBESS to improve overall system economic efficiency and reliability. On the basis of this model, a framework was proposed to optimally allocate MBESS/SBESS in a distribution system based on cost–benefit analysis. Using this approach, the optimal operation schedules for MBESS and SBESS can be simultaneously obtained. The proposed optimisation problem uses a new evolution algorithm, a natural aggregation algorithm. A case study on the IEEE test system successfully verified the effectiveness of the proposed approach for the optimal allocation of MBESS/SBESS in distribution systems.
Complex signum non‐linearity for robust GNSS interference mitigation
Authors: Daniele Borio , Pau Closas
Published: April 2018

The performance of a global navigation satellite system (GNSS) receiver can be significantly degraded in the presence of pulsed interference and jamming. In this study, the authors leverage on tools from robust statistics to enhance the receiver performance, with jamming signals treated as outliers to the nominal, interference‐free model. Particularly, the signal samples are pre‐processed with a zero‐memory non‐linearity (ZMNL), which limits the impact of pulsed inference in a principled way. A possible approach for the design of such ZMNL is provided by the M‐estimator framework when the noise at the receiver input is modelled with a heavy‐tailed distribution. This approach is adopted in this study and the complex signum non‐linearity is analysed. This ZMNL is obtained by considering a complex Laplacian noise. This choice is discussed and analysed in the context of GNSS receivers under jamming. The impact of the complex signum non‐linearity is theoretically analysed under nominal conditions, that is, in the absence of interference. Theoretical results are supported by Monte Carlo simulations. Real GNSS signals, collected in the presence of jamming, are used to demonstrate the advantages brought by the complex signum non‐linearity. Theoretical and experimental results demonstrate the benefits of the proposed approach.
Non‐enzymatic continuous glucose monitoring system
Authors: Moore Sean , You Byoung Hee , Kim Namwon , Park Taehyun , Song In‐Hyouk
Published: April 2018

A prominent field of study in biosensor development is the study of electric properties which provide valuable insight into the fluids contents. In this research, a non‐enzymatic glucose sensor is fabricated, characterised, and employed. The developed device determines the effects of electrode surface area on sensing efficacy, the effects of glucose concentration on impedimetric response, and a real‐time measurement of glucose concentration. Deviations throughout the entire glucose range are detected as an inverse of the impedance in the cell due to the inverse relationship of glucose concentration and charge transfer resistance. The continuous monitoring of glucose is demonstrated by a rapid device response over two iterations of glucose concentration in ascending order: 50 µM, 400 µM, and 3.2 mM. At a sustained frequency of 10 kHz, the result shows a stable impedimetric response of 1038, 752, and 688 kΩ, respectively. The validity of the device as a continuous glucose monitoring method is carried out by repeating the cycle and observing the response.
Gaia Data Release 2
Authors: Andrae René , Fouesneau Morgan , Creevey Orlagh , Ordenovic Christophe , Mary Nicolas , Burlacu Alexandru , Chaoul Laurence , Jean-Antoine-Piccolo Anne , Kordopatis Georges , Korn Andreas , Lebreton Yveline , Panem Chantal , Pichon Bernard , Thévenin Frédéric , Walmsley Gavin , Bailer-Jones Coryn A. L.
Published: April 2018

The second Gaia data release (Gaia DR2) contains, beyond the astrometry, three-band photometry for 1.38 billion sources. One band is the G band, the other two were obtained by integrating the Gaia prism spectra (BP and RP). We have used these three broad photometric bands to infer stellar effective temperatures, Teff, for all sources brighter than G = 17 mag with Teff in the range 3000–10 000 K (some 161 million sources). Using in addition the parallaxes, we infer the line-of-sight extinction, AG, and the reddening, E(BP − RP), for 88 million sources. Together with a bolometric correction we derive luminosity and radius for 77 million sources. These quantities as well as their estimated uncertainties are part of Gaia DR2. Here we describe the procedures by which these quantities were obtained, including the underlying assumptions, comparison with literature estimates, and the limitations of our results. Typical accuracies are of order 324 K (Teff), 0.46 mag (AG), 0.23 mag (E(BP − RP)), 15% (luminosity), and 10% (radius). Being based on only a small number of observable quantities and limited training data, our results are necessarily subject to some extreme assumptions that can lead to strong systematics in some cases (not included in the aforementioned accuracy estimates). One aspect is the non-negativity contraint of our estimates, in particular extinction, which we discuss. Yet in several regions of parameter space our results show very good performance, for example for red clump stars and solar analogues. Large uncertainties render the extinctions less useful at the individual star level, but they show good performance for ensemble estimates. We identify regimes in which our parameters should and should not be used and we define a “clean” sample. Despite the limitations, this is the largest catalogue of uniformly-inferred stellar parameters to date. More precise and detailed astrophysical parameters based on the full BP/RP spectrophotometry are planned as part of the third Gaia data release.
Accurate rest frequencies for propargylamine in the ground and low-lying vibrational states
Authors: Degli Esposti C. , Dore L. , Puzzarini C. , Biczysko M. , Bloino J. , Bizzocchi L. , Lattanzi V. , Grabow J.-U.
Published: April 2018

Context.To date, several complex organic molecules have been detected in the interstellar medium, and they have been suggested as precursors of biologically important species. Propargylamine (HC ≡C−CH2−NH2) is structurally similar to a number of other organic molecules which have already been identified by radioastronomy, making it a good candidate for astrophysical detection.

Aims.This work provides accurate rest frequencies of propargylamine, from the centimeter-wave to the submillimeter-wave region, useful to facilitate the detection of this molecule in the interstellar medium.

Methods.An extensive laboratory study of the rotational spectrum of propargylamine has been performed using a pulsed-jet Fourier Transform Microwave (FTMW) spectrometer (7–19 GHz frequency range) and a frequency modulation microwave spectrometer (75–560 GHz). Several hundred rotational transitions of propargylamine were recorded in the ground and three lowest excited vibrational states. The experiments were supported by high-level ab initio computations, mainly employed to characterize the vibrational state structure and to predict spectroscopic parameters unknown prior to this study.

Results.The measured transition frequencies yielded accurate rotational constants and the complete sets of quartic and sextic centrifugal distortion constants for propargylamine in its vibrational ground state.14N-nuclear quadrupole coupling constants were also determined. Rotational and quartic centrifugal distortion constants were also obtained for the low-lying excited statesv13= 1 (A′),v20= 1 (A″), andv21= 1 (A″). Thea-type Coriolis resonance which couples thev13= 1 andv21= 1 levels was analyzed.

Conclusions.The determined spectroscopic constants allowed for the compilation of a dataset of highly accurate rest frequencies for astrophysical purposes in the millimeter and submillimeter regions with 1σuncertainties that are smaller than 0.050 MHz, corresponding to 0.03 km s−1at 500 GHz in radial equivalent velocity.
Gaia Data Release 2
Authors: Sartoretti P. , Katz D. , Cropper M. , Panuzzo P. , Seabroke G. M. , Viala Y. , Benson K. , Blomme R. , Jasniewicz G. , Jean-Antoine A. , Huckle H. , Smith M. , Baker S. , Crifo F. , Damerdji Y. , David M. , Dolding C. , Frémat Y. , Gosset E. , Guerrier A. , Guy L. P. , Haigron R. , Janßen K. , Marchal O. , Plum G. , Soubiran C. , Thévenin F. , Ajaj M. , Allende Prieto C. , Babusiaux C. , Boudreault S. , Chemin L. , Delle Luche C. , Fabre C. , Gueguen A. , Hambly N. C. , Lasne Y. , Meynadier F. , Pailler F. , Panem C. , Riclet F. , Royer F. , Tauran G. , Zurbach C. , Zwitter T. , Arenou F. , Gomez A. , Lemaitre V. , Leclerc N. , Morel T. , Munari U. , Turon C. , Žerjal M.
Published: April 2018

Context. The Gaia Data Release 2 (DR2) contains the first release of radial velocities complementing the kinematic data of a sample of about 7 million relatively bright, late-type stars.

Aims. This paper provides a detailed description of the Gaia spectroscopic data processing pipeline, and of the approach adopted to derive the radial velocities presented in DR2.

Methods. The pipeline must perform four main tasks: (i) clean and reduce the spectra observed with the Radial Velocity Spectrometer (RVS); (ii) calibrate the RVS instrument, including wavelength, straylight, line-spread function, bias non-uniformity, and photometric zeropoint; (iii) extract the radial velocities; and (iv) verify the accuracy and precision of the results. The radial velocity of a star is obtained through a fit of the RVS spectrum relative to an appropriate synthetic template spectrum. An additional task of the spectroscopic pipeline was to provide first-order estimates of the stellar atmospheric parameters required to select such template spectra. We describe the pipeline features and present the detailed calibration algorithms and software solutions we used to produce the radial velocities published in DR2.

Results. The spectroscopic processing pipeline produced median radial velocities for Gaia stars with narrow-band near-IR magnitude GRVS ≤ 12 (i.e. brighter than V ~ 13). Stars identified as double-lined spectroscopic binaries were removed from the pipeline, while variable stars, single-lined, and non-detected double-lined spectroscopic binaries were treated as single stars. The scatter in radial velocity among different observations of a same star, also published in Gaia DR2, provides information about radial velocity variability. For the hottest (Teff ≥ 7000 K) and coolest (Teff ≤ 3500 K) stars, the accuracy and precision of the stellar parameter estimates are not sufficient to allow selection of appropriate templates. The radial velocities obtained for these stars were removed from DR2. The pipeline also provides a first-order estimate of the performance obtained. The overall accuracy of radial velocity measurements is around ~200–300 m s−1, and the overall precision is ~1 km s−1; it reaches ~200 m s−1 for the brightest stars.
Understanding a Deep Learning Technique through a Neuromorphic System a Case Study with SpiNNaker Neuromorphic Platform
Authors: Sugiarto Indar , Pasila Felix
Published: April 2018

Deep learning (DL) has been considered as a breakthrough technique in the field of artificial intelligence and machine learning. Conceptually, it relies on a many-layer network that exhibits a hierarchically non-linear processing capability. Some DL architectures such as deep neural networks, deep belief networks and recurrent neural networks have been developed and applied to many fields with incredible results, even comparable to human intelligence. However, many researchers are still sceptical about its true capability: can the intelligence demonstrated by deep learning technique be applied for general tasks? This question motivates the emergence of another research discipline: neuromorphic computing (NC). In NC, researchers try to identify the most fundamental ingredients that construct intelligence behaviour produced by the brain itself. To achieve this, neuromorphic systems are developed to mimic the brain functionality down to cellular level. In this paper, a neuromorphic platform called SpiNNaker is described and evaluated in order to understand its potential use as a platform for a deep learning approach. This paper is a literature review that contains comparative study on algorithms that have been implemented in SpiNNaker.
Numerical Study of Jet Impingement Heat Transfer on A Roughened Flat Plate
Authors: Alenezi A.H. , Almutairi Abdulrahman , Alhajeri Hamad M. , Addali A
Published: April 2018

The purpose of this research paper is to investigate the effect of surface roughness on heat transfer. This was achieved by investigating the heat transfer in two cases: a smooth, horizontal surface (the baseline case) and the same surface with a roughness element added to it. The roughness elements took the shape of cubical pin-fin. The roughness element was further investigated by varying its height and width (e by e) to study their impact on the average Nu. Results are presented in the form of average Nusselt number Nu within and beyond the stagnation region. Each roughness element was arranged in a circle concentric with the geometric centre (i.e. centre of jet) with a radius of one and a half jet diameters (R/D = 1.5) The jet diameter kept constant for all simulations (D=13.5mm) where the plane was located at H/D = 6 below the jet, for all the tests with a jet Reynolds number of 20,000 and jet temperature is 20°. The cubical pin-fin was tested for six different heights (e) from 0.25 mm to 1.50 mm in incremental steps of 0.25 mm for jet angle (α) of 90°.
Combining first- and third-person data in Sports Sciences in France: analysis of an original methodology
Authors: Favier-Ambrosini Brice , Quidu Matthieu
Published: April 2018

Classically studied from independent methodologies and compartmentalized research programs, first person data (documenting the actor’s personal experience from his own standpoint) and third-person data (data produced from the point of view of an outside observer, without reference to what the actor can feel and independently of his own point of view) have been braided together this past decade with a view to access a more complete and complex outlook on actions. How exactly has the field of French Sports Sciences contributed to the propagation of this original methodology consisting in confronting heterogeneous materials? Our epistemological analysis investigates the social and epistemic conditions of its genesis (progressive conquest of diversified subjects, reference toexemplarstudies, dissemination from a core group of authors, etc.) until the establishment of an activity close to normal science. It also formalizes the diversity of the methods of joint analysis between these data (correlation, heuristic discordance, etc.) before evaluating the knowledge effects specifically generated (reinforcement of robustness through triangulation, discovery of new regularities, transformation of intervention practices, etc.). Ultimately, combining first and third-person descriptions is an actual example of a genuinely interdisciplinary practice.
Cannabis auf Rezept – Wunderpflanze Hanf
Authors: Herz Mona
Published: April 2018

Seit März 2017 können Ärzte Cannabisblüten oder -extrakte Patienten verordnen, die an einer schwerwiegenden Erkrankung leiden. Das Gesetz legitimiert die Hanftherapie, wenn diese den Krankheitsverlauf verbessern und Symptome lindern kann. Doch nicht jeder ist für den Medizinalhanf geeignet.
15 Jahre physiopraxis – Heißhunger nach Wissen
Authors: Dieterich Angela
Published: April 2018

Physios sind wissensdurstig. Kommunikationskanäle wie Fachzeitschriften sind folglich sinnvoll. Die Autoren und das Redaktionsteam nehmen ihre Aufgaben sehr ernst. physiopraxis informiert, ordnet ein, stellt Fragen, bietet Lösungen, lädt zum Reflektieren ein. Nun schaut sie auf 15 erfolgreiche Jahre zurück. Vor ihr liegen sicher noch viele Jahre des Wandels einer Berufsgruppe, die ihren Heißhunger nach Wissen auf vielfältige Weise stillt. Was treibt uns Physios an?
Bedside Ultrasound-Guided Percutaneous Needle Aspiration of Intra- and Extra-Axial Intracranial Hemorrhage in Neonates
Authors: Cizmeci Mehmet , Thewissen Liesbeth , Zecic Alexandra , Woerdeman Peter , Boer Bart , Baert Edward , Govaert Paul , Dudink Jeroen , Groenendaal Floris , Lequin Maarten , de Vries Linda
Published: April 2018

Intracranial hemorrhage is an important cause of brain injury in the neonatal population and bedside percutaneous needle aspiration has emerged as an alternative due to the major risks that can be caused by standard neurosurgical decompression. We aimed to assess the effectiveness of this minimally invasive bedside technique and conducted a retrospective analysis of all newborn infants with a large extra-axial hemorrhage associated with a parenchymal hemorrhage causing a midline shift, managed at three academic centers over a 15-year period. Collected data included clinical history, laboratory results, review of all imaging studies performed, and neurodevelopmental follow-up. Eight infants (3 preterm and 5 full-term) presented on day 1 to 2 with seizures (n = 6) and apneas (n = 5), signs of increased intracranial pressure (n = 4), and coning (n = 1). Risk factors were present in six. Cranial ultrasound and computed tomography showed a midline shift in all; two infants showed status epilepticus on amplitude-integrated electroencephalography with complete resolution after the procedure. Between 7 and 34 mL could be aspirated associated with a decrease in the midline shift as seen by ultrasonography performed during the puncture. No complications were seen related to the procedure and none of the infants required further acute neurosurgical intervention. On follow-up, three had mild sequelae, including motor coordination problems (n = 1) and hemianopia (n = 2); none developed cerebral palsy or postneonatal epilepsy. Neonates, presenting with severe symptoms, can be managed successfully using ultrasound-guided needle aspiration and this minimally invasive bedside method should be kept in mind before performing neurosurgical decompression.
Reevaluation of Protein Intake for Preterm Infants
Authors: Kawai Masahiko
Published: April 2018

Growth failure caused by undernutrition is considered one of the major causes for psychomotor delay in extremely preterm infants, and the concept for “aggressive nutritional approach” is widely accepted worldwide. Based on this, postnatal early catch-up growth due to sufficient supply of nutrients including sufficient amounts of amino acids is believed to be essential for a better outcome; however, there is no definitive evidence of aggressive nutrition on better outcomes in mortality, growth, and neurodevelopment. On the contrary, epidemiological evidence suggests that low birth weight and a rapid catch-up growth after birth are major risk factors for insulin resistance and diabetes in later life; higher protein intake during postnatal period relates to higher cardiovascular risk in later life. Considering these, optimal nutrition, especially protein administration, should be reevaluated. In this review, current opinions on the nutrition for the preterm infants are surveyed. In addition, I propose a new concept for optimized protein amount for the preterm infants based on the difference of amino acid metabolism between fetuses and preterm infants.
Update on the Role of Stem Cells in the Treatment of Hirschsprung Disease
Authors: Lui Kathy , Tam Paul , Ngan Elly
Published: April 2018

Stem cells possess the ability of self-renewal and the potency to differentiate into multiple cell lineages. Somatic stem cells are present in adult tissues, but they usually exhibit limited differentiation capacity and life span. On the other hand, somatic cells from adult tissues can be reprogrammed into induced pluripotent stem cells (iPSCs) that retain a full differentiation capacity with unlimited self-renewal ability. Autologous origin of iPSCs makes them an ideal source of cells for regenerative medicine to replenish the missing or damaged cells in the patients. iPSCs nowadays have also been widely used to build human disease models to study pathological mechanisms of the diseases. Hirschsprung disease (HSCR) is a congenital disorder caused by defects in the development of enteric neural crest stem cells. The failures of the ENCCs to proliferate, differentiate, and/or migrate lead to the absence of enteric neurons in the distal colon, resulting in colonic motility dysfunction. The lack of effective treatment for HSCR urges continuous efforts to develop new therapies for this congenital disorder. In this review, we will discuss the potential applications of somatic stem cells and iPSCs for the cell-based therapy of HSCR. We will also highlight the recent advances in stem cell research for the establishment of human HSCR models for the development of novel therapies.
The construction of new scientific norms for solving Grand Challenges
Authors: Maxwell Kate , Benneworth Paul
Published: April 2018

There is an increasing recognition that there is a class of problems that society must solve urgently in the twenty-first century if humanity is to survive into the twenty-second century—the so-called ‘Grand Challenges’. Science policymakers have been active in recognising these challenges and the attendant need to develop new multidisciplinary ways of working. But embracing multidisciplinarity is not a straightforward choice for scientists, who individually are strongly steered by norms and values inculcated through their past scientific experiences. In this paper, therefore, we ask whether new funding approaches can contribute to creating new ways of working by scientists towards challenge-driven research, specifically by changing scientists’ expectations and beliefs. We address this research question with reference to a single new experimental method, the ‘research sandpit’, implemented experimentally in a single national science system, Norway. Our data are derived from interviews with scientists involved in the five research projects funded as a result of the first sandpit, called ‘Idélab’ (idea lab) and held in 2014, and with the Research Council of Norway. We conclude that the sandpit approach appeared to shift research perceptions of individual scientists, particularly around long-term belief structures. This implies that, when well managed, the sandpit model can indeed be useful to generate multidisciplinary research as part of a multifaceted approach to funding scientific research.
Impact of undamped and damped intramolecular vibrations on the efficiency of photosynthetic exciton energy transfer
Authors: Juhász Imre Benedek , Csurgay Árpád I.
Published: April 2018

In recent years, the role of molecular vibrations in exciton energy transfer taking place during the first stage of photosynthesis attracted increasing interest. Here, we present a model formulated as a Lindblad-type master equation that enables us to investigate the impact of undamped and especially damped intramolecular vibrational modes on the exciton energy transfer, particularly its efficiency. Our simulations confirm the already reported effects that the presence of an intramolecular vibrational mode can compensate the energy detuning of electronic states, thus promoting the energy transfer; and, moreover, that the damping of such a vibrational mode (in other words, vibrational relaxation) can further enhance the efficiency of the process by generating directionality in the energy flow. As a novel result, we show that this enhancement surpasses the one caused by pure dephasing, and we present its dependence on various system parameters (time constants of the environment-induced relaxation and excitation processes, detuning of the electronic energy levels, frequency of the intramolecular vibrational modes, Huang–Rhys factors, temperature) in dimer model systems. We demonstrate that vibrational-relaxation-enhanced exciton energy transfer (VREEET) is robust against the change of these characteristics of the system and occurs in wide ranges of the investigated parameters. With simulations performed on a heptamer model inspired by the Fenna–Matthews–Olson (FMO) complex, we show that this mechanism can be even more significant in larger systems at T = 300 K. Our results suggests that VREEET might be prevalent in light-harvesting complexes.
Effect of substrate rotation speed and off-center deposition on the structural, optical, and electrical properties of AZO thin films fabricated by DC magnetron sputtering
Authors: Turkoglu F. , Koseoglu H. , Zeybek S. , Ozdemir M. , Aygun G. , Ozyuzer L.
Published: April 2018

In this study, aluminum-doped zinc oxide (AZO) thin films were deposited by DC magnetron sputtering at room temperature. The distance between the substrate and target axis, and substrate rotation speed were varied to get high quality AZO thin films. The influences of these deposition parameters on the structural, optical, and electrical properties of the fabricated films were investigated by X-ray diffraction (XRD), Raman spectroscopy, spectrophotometry, and four-point probe techniques. The overall analysis revealed that both sample position and substrate rotation speed are effective in changing the optical, structural, and electrical properties of the AZO thin films. We further observed that stress in the films can be significantly reduced by off-center deposition and rotating the sample holder during the deposition. An average transmittance above 85% in the visible range and a resistivity of 2.02 × 10−3 Ω cm were obtained for the AZO films.
Endoreversible model of thermal to radiative energy converters
Authors: Fernández Julio J.
Published: April 2018

In this work, we present a general endoreversible model to calculate the efficiency and the output power of energy emissive harvesters. Our model improves previous models since it includes the entropy losses associated to the energy transport happening in the energy emissive harvesters. Our model is developed for both harvesters exchanging energy with the environment through the full spectrum and when the exchange is mediated by a bandgap. For cells exchanging energy through a bandgap, we use the concept of electronic temperature previously introduced by Strandberg to model the operation of the cells at different polarization voltages and to make a model for thermoradiative cells. We calculate the output power and the efficiency of cold-carrier emissive energy harvesters working at temperatures between 300 and 500 K in environments with temperatures between 50 and 300 K. In the last part of the paper, we calculate the output power and the efficiency of thermoradiative cells working at different polarization voltages. We compare our results to those obtained in the works of Byrnes and Strandberg.
Faraday waves in a Hele-Shaw cell
Authors: Li Jing , Li Xiaochen , Chen Kaijie , Xie Bin , Liao Shijun
Published: April 2018

We investigate Faraday waves in a Hele-Shaw cell via experimental, numerical, and theoretical studies. Inspired by the Kelvin-Helmholtz-Darcy theory, we develop the gap-averaged Navier-Stokes equations and end up with the stable standing waves with half frequency of the external forced vibration. To overcome the dependency of a numerical model on the experimental parameter of wave length, we take two-phase flow into consideration and a novel dispersion relation is derived. The numerical results compare well with our experimental data, which effectively validates our proposed mathematical model. Therefore, this model can produce robust solutions of Faraday wave patterns and resolve related physical phenomena, which demonstrates the practical importance of the present study.
Unsteady separated stagnation-point flow and heat transfer of a viscous fluid over a moving flat surface
Authors: Dholey S.
Published: April 2018

In this paper, we have investigated numerically the laminar unsteady separated stagnation-point flow and heat transfer of a viscous fluid over a moving flat surface in the presence of a time dependent free stream velocity which causes the unsteadiness of this flow problem. The plate is assumed to move in the same or opposite direction of the free stream velocity. The flow is therefore governed by the velocity ratio parameter λ (ratio of the plate velocity to the free stream velocity) and the unsteadiness parameter β. When the plate surface moves in the same direction of the free stream velocity (i.e., when λ > 0), the solution of this flow problem continues for any given value of β. On the other hand, when they move in opposite directions (i.e., when λ < 0), the solution does not exist after a certain value of λ depending upon the values of β. In this case, separation appears inside the layer only for a negative value of β, and for a positive value of β, the boundary layer solution is terminated after a certain distance from the plate surface with an attached flow solution with no point of inflection. The concerning issue of the steady flow (β = 0) case has also been considered and two types of attached flow solutions have been found—one with a point of inflection and the other with no point of inflection, in a definite range of λ (−1.246 58 ≤ λ ≤ −1.07). However, this range decreases with an increase in |β| when β < 0. A novel result which arises from the heat transfer analysis is that for a given value of λ(= 0), first the heat transfer rate increases with the increase of the Prandtl number Pr and after attaining a maximum value, it decreases and finally tends to be zero for large values of Pr depending upon the values of β > 0. On the contrary, for a given value of β(≤ 0), the rate of heat transfer increases consistently with the increase of Pr.
Band alignment of 2D WS2/HfO2 interfaces from x-ray photoelectron spectroscopy and first-principles calculations
Authors: Zhu H. L. , Zhou C. J. , Tang B. S. , Yang W. F. , Chai J. W. , Tay W. L. , Gong H. , Pan J. S. , Zou W. D. , Wang S. J. , Chi D. Z.
Published: April 2018

We report on the growth of two-dimensional (2D) WS2 on high-k HfO2/Si substrates by reactive sputtering deposition. Raman, x-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy characterizations indicate that the 2D WS2 layers exhibit high-quality crystallinity and exact stoichiometry. Through high-resolution XPS valence spectra, we find a type I alignment at the interface of monolayer WS2/HfO2 with a valence band offset (VBO) of 1.95 eV and a conduction band offset (CBO) of 1.57 eV. The VBO and CBO are also found to increase up to 2.24 eV and 2.09 eV, respectively, with increasing WS2 layers. This is consistent with the results obtained from our first-principles calculations. Our theoretical calculations reveal that the remarkable splitting and shift of the W 5dz2 orbital originating from interlayer orbital coupling in thicker WS2 films induce a reduction of its bandgap, leading to an increase in both the VBO and CBO. This observation can be attributed to the asymmetric splitting at different high symmetric k-points caused by the interlayer orbital coupling.
Telecom wavelength single quantum dots with very small excitonic fine-structure splitting
Authors: Kors Andrei , Reithmaier Johann Peter , Benyoucef Mohamed
Published: April 2018

We report on molecular beam epitaxy growth of symmetric InAs/InP quantum dots (QDs) emitting at a telecom C-band (1.55 μm) with an ultra-small excitonic fine-structure splitting of ∼2 μeV. The QDs are grown on a distributed Bragg reflector (DBR) and systematically characterized by micro-photoluminescence (μ-PL) measurements. One order of magnitude of QD PL intensity enhancement is observed in comparison to the samples without DBR. A combination of power-dependent and polarization-resolved measurements reveals background-free exciton, biexciton, and dark exciton emission with a resolution-limited linewidth below 35 μeV and a biexciton binding energy of ∼1 meV. The results are confirmed by statistical measurements of about 20 QDs.
Enhanced pyroelectric properties and thermal stability of Mn-doped 0.29Pb(In1/2Nb1/2)O3-0.29Pb(Mg1/3Nb2/3)O3–0.42PbTiO3 single crystals
Authors: Li Yue , Tang Yanxue , Chen Jianwei , Zhao Xiangyong , Yang Linrong , Wang Feifei , Zeng Zhou , Luo Haosu
Published: April 2018

The pyroelectric properties and thermal stability of a [001]-oriented tetragonal 1 mol. % Mn-doped 0.29Pb(In1/2Nb1/2)O3-0.29Pb(Mg1/3Nb2/3)O3-0.42PbTiO3 [Mn-PIN-PMN-PT(29/29/42)] ternary single crystal were investigated. The single crystal exhibited a high pyroelectric coefficient of p = 6.0 × 10−4 C m−2 K−1 and figures of merit (FOMs) at 1 kHz for a current responsivity of Fi = 2.4 × 10−10 mV−1, a voltage responsivity of Fv = 0.08 m2 C−1, and a detectivity of Fd = 19.8 × 10−5 Pa−1/2 which were weakly dependent on frequency. These all increased linearly upon increasing temperature to 120 °C. Furthermore, the values of p for the ternary single crystal were weakly dependent on thermal annealing temperatures (Ta), maintaining over 75% of the original value at Ta < 160 °C, which was 70 °C higher than that of the [111]-oriented rhombohedral 1 mol. % Mn-doped 0.73Pb(Mg1/3Nb2/3)O3–0.27PbTiO3 [Mn-PMN-PT(73/27)] binary single crystal. These excellent pyroelectric properties, together with good thermal stability and wide operational temperature, make the [001]-oriented tetragonal Mn-PIN-PMN-PT(29/29/42) single crystal a promising candidate for pyroelectric detection and thermal imaging applications.
Significance of the gate voltage-dependent mobility in the electrical characterization of organic field effect transistors
Authors: Kim Jong Beom , Lee Dong Ryeol
Published: April 2018

We studied the effect of the addition of free hole- and electron-rich organic molecules to organic semiconductors (OSCs) in organic field effect transistors (OFETs) on the gate voltage-dependent mobility. The drain current versus gate voltage characteristics were quantitatively analyzed using an OFET mobility model of power law behavior based on hopping transport in an OSC. This analysis distinguished the threshold voltage shifts, depending on the materials and structures of the OFET device, and properly estimated the hopping transport of the charge carriers induced by the gate bias within the OSC from the power law exponent parameter. The addition of pentacene or C60 molecules to a one-monolayer pentacene-based OFET shifted the threshold voltages negatively or positively, respectively, due to the structural changes that occurred in the OFET device. On the other hand, the power law parameters revealed that the addition of charge carriers of the same or opposite polarity enhanced or hindered hopping transport, respectively. This study revealed the need for a quantitative analysis of the gate voltage-dependent mobility while distinguishing this effect from the threshold voltage effect in order to understand OSC hopping transport in OFETs.
Demonstration of high mobility and quantum transport in modulation-doped β-(AlxGa1-x)2O3/Ga2O3 heterostructures
Authors: Zhang Yuewei , Neal Adam , Xia Zhanbo , Joishi Chandan , Johnson Jared M. , Zheng Yuanhua , Bajaj Sanyam , Brenner Mark , Dorsey Donald , Chabak Kelson , Jessen Gregg , Hwang Jinwoo , Mou Shin , Heremans Joseph P. , Rajan Siddharth
Published: April 2018

In this work, we demonstrate a high mobility two-dimensional electron gas (2DEG) formed at the β-(AlxGa1-x)2O3/Ga2O3 interface through modulation doping. Shubnikov-de Haas (SdH) oscillations were observed in the modulation-doped β-(AlxGa1-x)2O3/Ga2O3 structure, indicating a high-quality electron channel formed at the heterojunction interface. The formation of the 2DEG channel was further confirmed by the weak temperature dependence of the carrier density, and the peak low temperature mobility was found to be 2790 cm2/Vs, which is significantly higher than that achieved in bulk-doped Beta-phase Gallium Oxide (β-Ga2O3). The observed SdH oscillations allowed for the extraction of the electron effective mass in the (010) plane to be 0.313 ± 0.015 m0 and the quantum scattering time to be 0.33 ps at 3.5 K. The demonstrated modulation-doped β-(AlxGa1-x)2O3/Ga2O3 structure lays the foundation for future exploration of quantum physical phenomena and semiconductor device technologies based on the β-Ga2O3 material system.