bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel approach for rhodium(iii)-catalyzed C–H functionalization of 2,2′-bipyridine derivatives with alkynes: a significant substituent effect
Authors: Wu Shaonan , Wang Zhuo , Bao Yinwei , Chen Chen , Liu Kun , Zhu Bolin
Published: March 2020

A novel approach for rhodium(iii)-catalyzed C–H functionalization of 2,2′-bipyridine derivatives was developed, which elucidated significant substituent effects on the rollover cyclometalation.
Highly selective production of linear 1-heptadecene from stearic acid over a partially reduced MoOx catalyst
Authors: Zhang Zihao , Li Yafei , Okejiri Francis , Liu Miaomiao , Chen Hao , Liu Jixing , Chen Kequan , Lu Xiuyang , Ouyang Pingkai , Fu Jie
Published: March 2020

Here, a MoOx-T-based catalyst was developed by a simple reduction of MoO3 precursors at different temperatures.
Different effects in the selective detection of aniline and Fe3+ by lanthanide-based coordination polymers containing multiple reactive sites
Authors: Liu Xinfang , Du Liyong , Li Rongfang , Ma Ningning , You Mengdi , Feng Xun
Published: March 2020

Isostructural Ln-CPs (1-Eu and 2-Tb) show almost the same high detection ability for Fe3+ and different detection abilities for aniline. The detection difference was studied through PXRD, UV-vis, luminescence lifetimes and Hirshfeld surface analysis.
TD-DFT benchmark for UV-visible spectra of fused-ring electron acceptors using global and range-separated hybrids
Authors: Ali Amjad , Rafiq Muhammad Imran , Zhang Zhuohan , Cao Jinru , Geng Renyong , Zhou Baojing , Tang Weihua
Published: March 2020

The accuracy of Time-Dependent Density Functional Theory in predicting the vertical absorption wavelength of 50 widely-used fused-ring electron acceptors (FREAs) has been investigated by considering the solvent effects.
Stabilities of group-III phosphide (MP, M = B, Al, Ga and In) monolayers in oxygen and water environments
Authors: Wu Jie , Li Jia-Hui , Yu Yang-Xin
Published: March 2020

BP monolayer is stable in a water–oxygen atmosphere, while AlP monolayer is unstable in both oxygen and water environments.
Isochoric measurement of the evaporation point of pure fluids in bulk and nanoporous media using differential scanning calorimetry
Authors: Qiu Xingdong , Tan Sugata P. , Dejam Morteza , Adidharma Hertanto
Published: March 2020

Evaporation-point measurement of pure fluids in bulk and nanopores using an isochoric heating process.
A ceramic microchip with LDA-APGD as the excitation source for OES – a sensitive Hg detecting sensor for microsample analysis
Authors: Swiderski Krzysztof , Matusiak Tomasz , Wozinski Mateusz , Dabrowski Arkadiusz , Golonka Leszek , Pohl Pawel , Jamroz Piotr
Published: March 2020

A novel portable excitation microsource for optical emission spectrometry (OES) based on atmospheric pressure glow discharge with a liquid drop anode (LDA-APGD), generated in a ceramic microchip (mch), was developed.
Multi-genomic analysis of the cation diffusion facilitator transporters from algae
Authors: Ibuot Aniefon , Dean Andrew P , Pittman Jon K
Published: March 2020

Metal transport processes are relatively poorly understood in algae in comparison to higher plants and other eukaryotes. A screen of genomes from 33 taxonomically diverse algal species was conducted to identify members of the Cation Diffusion Facilitator (CDF) family of metal ion transporter. All algal genomes contained at least one CDF gene with four species having >10 CDF genes (median of 5 genes per genome), further confirming that this is a ubiquitous gene family. Phylogenetic analysis suggested a CDF gene organisation of five groups, which includes Zn-CDF, Fe/Zn-CDF and Mn-CDF groups, consistent with previous phylogenetic analyses, and two functionally undefined groups. One of these undefined groups was algal specific although excluded chlorophyte and rhodophyte sequences. The majority of sequences (22 out of 26 sequences) from this group had a putative ion binding site motif within transmembrane domain 2 and 5 that was distinct from other CDF proteins, such that alanine or serine replaced the conserved histidine residue. The phylogenetic grouping was supported by sequence cluster analysis. Yeast heterologous expression of CDF proteins from Chlamydomonas reinhardtii indicated Zn2+ and Co2+ transport function by CrMTP1, and Mn2+ transport function by CrMTP2, CrMTP3 and CrMTP4, which validated the phylogenetic prediction. However, the Mn-CDF protein CrMTP3 was also able to provide zinc and cobalt tolerance to the Zn- and Co-sensitive zrc1 cot1 yeast strain. There is wide diversity of CDF transporters within the algae lineage, and some of these genes may be attractive targets for future applications of metal content engineering in plants or microorganisms.
IrIII-Catalyzed direct syntheses of amides and esters using nitriles as acid equivalents: a photochemical pathway
Authors: Talukdar Ranadeep
Published: March 2020

An unprecedented IrIII[df(CF3)ppy]2(dtbbpy)PF6-catalyzed simple photochemical process for direct addition of amines and alcohols to the relatively less reactive nitrile triple bond is described herein.
Reusable, few-layered-MoS2 nanosheets/graphene hybrid on cellulose paper for superior adsorption of methylene blue dye
Authors: Gopalakrishnan Arthi , Singh Satyam Pratap , Badhulika Sushmee
Published: March 2020

High efficient methylene blue adsorption by MoS2 micro-flowers on graphene-cellulose paper.
Enhanced Li-ion storage performance of novel tube-in-tube structured nanofibers with hollow metal oxide nanospheres covered with a graphitic carbon layer
Authors: Park Gi Dae , Kang Yun Chan
Published: March 2020

In this research, a rational strategy to produce novel tube-in-tube structured nanofibers consisting of hollow CoFe2O4@GC nanospheres is introduced. The pitch solution was applied to provide high electrical conductivity and structural stability.
Organocatalyzed ring-opening polymerization (ROP) of functional β-lactones: new insights into the ROP mechanism and poly(hydroxyalkanoate)s (PHAs) macromolecular structure
Authors: Shakaroun Rama M. , Jéhan Philippe , Alaaeddine Ali , Carpentier Jean-François , Guillaume Sophie M.
Published: March 2020

The organocatalyzed ROP of some 4-alkoxymethylene-β-propiolactones (BPLORs) towards the formation of the corresponding poly(hydroxyalkanoate)s (PHAs; PBPLORs) is investigated simply using basic organocatalysts of the guanidine (TBD), amidine (DBU) or phosphazene (BEMP) type.
Chromium-catalyzed cyclopropanation of alkenes with bromoform in the presence of 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-dihydropyrazine
Authors: Ikeda Hideaki , Nishi Kohei , Tsurugi Hayato , Mashima Kazushi
Published: March 2020

Chromium-catalyzed cyclopropanation of alkenes with bromoform was achieved to produce the corresponding bromocyclopropanes.
Circulating lncRNA DANCR as a potential auxillary biomarker for the diagnosis and prognostic prediction of colorectal cancer
Authors: Shen Xianjuan , Xue Yajing , Cong Hui , Wang Xudong , Fan Zhiwei , Cui Xiaopeng , Ju Shaoqing
Published: March 2020

Studies have shown that long non-coding RNAs (lncRNAs) play vital roles in the development of cancer, including colorectal cancer (CRC). Our purpose is to validate the diagnostic value of serum differentiation antagonizing non-protein coding RNA (DANCR) in CRC by focusing on its expression and clinical application. lncRNA expression profiles of CRC patients were obtained and analyzed by repurposing the publically available microarray data. Tissue or serum specimens were obtained from 40 patients with primary CRC, 10 patients with recurrent CRC, 40 patients with colorectal polyps, and 40 healthy controls. It was found that DANCR level in the CRC tissue and serum was significantly increased, and serum DANCR expression was decreased in post-operative patients as compared with that in pre-treatment patients and recurrent patients. In addition, serum DANCR expression was significantly correlated with different TNM stages. Correlation analysis of DANCR and other diagnostic indicators showed that the serum DANCR expression level was significantly correlated with CA199 but not with CEA in CRC patients. As for diagnostic efficiency by ROC analysis, the area under the curve (AUC) of serum DANCR was higher than that of CEA and CA199 in CRC group vs. colorectal polyp group. Simultaneous detection of DANCR, CEA and CA199 yielded the highest sensitivity and AUC as compared with either of them alone. Taken together, serum DANCR was up-regulated in CRC patients and high expression of DANCR may prove to be a potential biomarker for the diagnosis of CRC.
Astragalus polysaccharides inhibit ovarian cancer cell growth via microRNA-27a/FBXW7 signaling pathway
Authors: Guo Yanling , Zhang Zhenxing , Wang Zhaoxia , Liu Guoqi , Liu Yingying , Wang Huijie
Published: March 2020

Astragalus polysaccharide (APS), a natural antioxidant found in Astragalus membranaceus emerging as a novel anticancer agent, exerts antiproliferative and pro-apoptotic activity in various cancer cell types, but its effect on ovarian cancer (OC) remains unknown. In the present study, we tried to elucidate the role and mechanism of APS in OC cells. Our results showed that APS treatment suppressed the proliferation and induced apoptosis in OC cells. Afterward, the microRNA (miRNA) profiles in APS-treated cells were determined by a microarray assay, and whether APS affected OV-90 cells through regulation of miRNA was determined. Among these aberrant miRNAs, miR-27a was selected for further study as its oncogenic roles in various human cancers. Moreover, we found overexpression of miR-27a reversed the antiproliferation and pro-apoptotic effects of APS on OC cells. F-box and WD-40 domain protein 7 (FBXW7), a classical tumor suppressor, was found directly targeted by miR-27a and its translation was suppressed by miR-27a in OC cells. Finally, it was also observed that knockdown of FBXW7 by si-FBXW7 reversed the tumor suppressive activity of APS in OC cells, which is similar to the effects of miR-27a overexpression. Our findings demonstrate that APS can suppress OC cell growth in vitro via miR-27a/FBXW7 axis, and this observation reveals the therapeutic potential of APS for treatment of OC.
A peek in the micro-sized world: a review of design principles, engineering tools, and applications of engineered microbial community
Authors: Gao Baizhen , Sabnis Rushant , Costantini Tommaso , Jinkerson Robert , Sun Qing
Published: March 2020

Microbial communities drive diverse processes that impact nearly everything on this planet, from global biogeochemical cycles to human health. Harnessing the power of these microorganisms could provide solutions to many of the challenges that face society. However, naturally occurring microbial communities are not optimized for anthropogenic use. An emerging area of research is focusing on engineering synthetic microbial communities to carry out predefined functions. Microbial community engineers are applying design principles like top-down and bottom-up approaches to create synthetic microbial communities having a myriad of real-life applications in health care, disease prevention, and environmental remediation. Multiple genetic engineering tools and delivery approaches can be used to ‘knock-in' new gene functions into microbial communities. A systematic study of the microbial interactions, community assembling principles, and engineering tools are necessary for us to understand the microbial community and to better utilize them. Continued analysis and effort are required to further the current and potential applications of synthetic microbial communities.
Event\self‐triggered leader‐following consensus of multi‐agent systems with general dynamics
Authors: Zhang Juan , Zhang Huaguang , Lu Yanzheng , Sun Shaoxin
Published: March 2020

The consensus problem for leader‐following multi‐agent systems with general dynamics via event‐triggered and self‐triggered mechanisms is studied. In the practical leader‐following systems, not all followers can access the information of the leader directly, so the agents are divided into two categories according to whether they receive the information of the leader directly or not. For the former, the authors only utilise the leader's state and its own state information to design the distributed consensus protocol, even if there are other neighbours. To achieve the consensus problem that each follower can ultimately track the state of the leader over time, two kinds of event‐triggered control schemes are designed for two types of agents, respectively. It is shown that the systems can achieve the consensus problem by utilising the event‐triggered mechanisms through a theorem. In this case, Zeno behaviour can be excluded. Furthermore, the self‐triggered control algorithm is also proposed to avoid continuous communication with neighbours and there is no Zeno behaviour in the systems. Finally, two examples are used to verify the validity of the main results.
NSST and vector‐valued C–V model based image segmentation algorithm
Authors: Wang Xianghai , Zhao Xiaoyang , Zhu Yihuan , Su Xin
Published: March 2020

Image segmentation is a process of partitioning an image into non‐overlapping regions. Existing unsupervised image segmentation methods include level set, automatic thresholding and region‐based CV mode and so on. However, image segmentation as a key technology in the field of image processing has not been solved indeed, especially for images with complex texture. For this reason, the authors proposed a novel image segmentation algorithm based on NSST and the vector‐valued Chan–Vese (C–V) model. First, they obtained a multi‐scale representation by exploiting the non‐subsampled shearlet transform (NSST) to extract multi‐dimensional data in the image. Afterwards, they gave the vector‐valued C–V model, and applied it to all subbands of NSST, which are treated as a vector‐valued image. By comparing with other class methods, the experimental results show that the proposed method has better visual effects and lower error rates. But at the same time, it is a little time consuming. The proposed method is reasonable and effective, by taking full advantages of each subband's directional information during its diffusion process, compared with traditional C–V model.
Optimised multi‐wavelet domain for decomposed electrooculogram‐based eye movement classification
Authors: Mulam Harikrishna , Mudigonda Malini
Published: March 2020

The human eye movement tracking is possible with the assistance of the electrooculography (EOG) signals. The human eye tracking system allows researchers to analyse the participant's eye movements during certain activities. This study offers the EOG signals to control the human–computer interface systems with the help of Empirical Mean Curve Decomposition (EMCD) decomposition model. At first, the input EOG signal is provided as input to the EMCD decomposition model, later the resultant signal is given to principal component analysis for dimensional reduction, and then the dimensional reduced signal is offered to multi‐wavelet decomposition model. The resultant dimensionally reduced multi‐wavelet decomposed signal is passed to the proposed Feature Mapping (FM) model, using the k‐means clustering model. Then, the Grey Wolf Optimization (GWO) algorithm is utilised to tune the margin. Next to mapping, the obtained features are provided to the nearest neighbour classifier, to obtain the eye movement. Next to the implementation, the proposed method is compared with the existing methods, and it is witnessed that the proposed methodology gives the superior performance in correspondence with accuracy, sensitivity, specificity, precision, false positive rate, false negative rate, negative predictive value, false discovery rate, F1 score and Mathews correlation coefficient.
Image copy‐move forgery detection algorithm based on ORB and novel similarity metric
Authors: Tian Xiuxia , Zhou Guoshuai , Xu Man
Published: March 2020

Image forgery poses a serious threat in electric power, medicine and other fields. Relevant departments need to pay a great price to identify the authenticity of the image. For traditional copy‐move forgery image detection, the existing methods have at least two problems: low robustness and poor matching caused by a low number of feature points. Here, a novel similarity metric combining cosine and Jaccard is proposed to improve feature matching, which combines with oriented features from accelerated segment test and rotated binary robust independent elementary features (ORB) feature extraction to realise effective and fast image forgery detection. First, the image is divided into overlapping blocks, and ORB is used to extract the feature points of each image block to obtain the text information. Second, the novel similarity metric is used to calculate similarity and match the text. Finally, two image blocks with the highest similarity are located. The experimental results show that, on the one hand, ORB can greatly lessen detection time. On the other hand, the novel similarity metric can improve the poor matching caused by the small number of feature points. Combining the two methods can exhibit high robustness to translation, rotation, noise, illumination and JPEG compression.
Deep3DSCan: Deep residual network and morphological descriptor based framework forlung cancer classification and 3D segmentation
Authors: Bansal Gaurang , Chamola Vinay , Narang Pratik , Kumar Subham , Raman Sundaresan
Published: March 2020

With the increasing incidence rate of lung cancer patients, early diagnosis could help in reducing the mortality rate. However, accurate recognition of cancerous lesions is immensely challenging owing to factors such as low contrast variation, heterogeneity and visual similarity between benign and malignant nodules. Deep learning techniques have been very effective in performing natural image segmentation with robustness to previously unseen situations, reasonable scale invariance and the ability to detect even minute differences. However, they usually fail to learn domain‐specific features due to the limited amount of available data and domain agnostic nature of these techniques. This work presents an ensemble framework Deep3DSCan for lung cancer segmentation and classification. The deep 3D segmentation network generates the 3D volume of interest from computed tomography scans of patients. The deep features and handcrafted descriptors are extracted using a fine‐tuned residual network and morphological techniques, respectively. Finally, the fused features are used for cancer classification. The experiments were conducted on the publicly available LUNA16 dataset. For the segmentation, the authors achieved an accuracy of 0.927, significant improvement over the template matching technique, which had achieved an accuracy of 0.927. For the detection, previous state‐of‐the‐art is 0.866, while ours is 0.883.
Fault‐tolerant control of dual three‐phase PMSG wind turbine drive system with one channel of faulty rectifier
Authors: Hu Yashan , Li Xuefei
Published: March 2020

This study proposes a fault‐tolerant control to suppress the second harmonic (2 h) torque ripple and DC bus voltage ripple simultaneously in dual three‐phase permanent‐magnet synchronous generator (PMSG) wind turbine drive system by negative‐sequence current compensation when one channel of the rectifier is faulty. In the dual three‐phase PMSG system with two channels of back‐to‐back rectifier/inverter, only the other healthy channel can keep working with up to half‐rated power if one channel of rectifier fails. In some scenarios, the healthy channel might be asymmetric, which will result in 2 h torque, power and corresponding DC bus voltage ripples in the reduced rectifier/inverter operation. In the previous research, the 2 h torque and DC bus voltage ripples are suppressed simultaneously by compensation with some extra hardware in parallel with DC bus or in series with phase windings, which increases the system cost. In this work, by utilising the inverter and three‐phase windings in the faulty channel which are still functional, the 2 h torque and DC bus voltage ripples can be suppressed effectively without any extra hardware, which is validated on a prototype dual three‐phase PMSG wind turbine drive system.
Time scale stability analysis of a Hopf bifurcation in a wind–diesel hybrid microgrid
Authors: Choque Pillco Edwin , Costa Alberto Luís Fernando , de Oliveira Ricardo Vasques
Published: March 2020

Microgrids and modern bulk power systems usually have multiple time scale dynamics, such as slow and fast dynamics. In this study, the stability of a wind–diesel hybrid microgrid is investigated to show a mechanism of system collapse caused by the interaction between fast dynamics of interface converters and slow electromechanical dynamics. This mechanism leads to a Hopf bifurcation of the fast subsystem due to slow changes in the variables of the slow subsystem and is completely understood by decomposing the stability analysis of the microgrid into the stability assessment of two simpler subsystems: the slow and the fast subsystems. The time‐scale method proposed in this study for stability analysis of the microgrid extends the existing proposals in the literature and is able to detect this kind of instability scenario, where the interaction between fast and slow subsystems is the cause of collapse, while the existing approaches, such as quasi‐steady‐state analysis, fail in detecting instability.
New mysteries and challenges from the Toothbrush relic: wideband observations from 550 MHz to 8 GHz
Authors: Rajpurohit K. , Hoeft M. , Vazza F. , Rudnick L. , van Weeren R. J. , Wittor D. , Drabent A. , Brienza M. , Bonnassieux E. , Locatelli N. , Kale R. , Dumba C.
Published: March 2020

Context.Radio relics are diffuse extended synchrotron sources that originate from shock fronts induced by galaxy cluster mergers. The particle acceleration mechanism at the shock fronts is still under debate. The galaxy cluster 1RXS J0603.3+4214 hosts one of the most intriguing examples of radio relics, known as the Toothbrush.

Aims.In order to understand the mechanism(s) that accelerate(s) relativistic particles in the intracluster medium, we investigated the spectral properties of large-scale diffuse extended sources in the merging galaxy cluster 1RXS J0603.3+4214.

Methods.We present new wideband radio continuum observations made with uGMRT and VLA. Our new observations, in combination with previously published data, allowed us to carry out a detailed high-spatial-resolution spectral and curvature analysis over a wide range of frequencies.

Results.The integrated spectrum of the Toothbrush closely follows a power law over almost two orders of magnitude in frequency, with a spectral index of −1.16 ± 0.02. We do not find any evidence of spectral steepening below 8 GHz. The subregions of the Toothbrush also exhibit near-perfect power laws and identical spectral slopes, suggesting that the observed spectral index is rather set by the distribution of Mach numbers which may have a similar shape at different parts of the shock front. Indeed, numerical simulations show an intriguing similar spectral index, indicating that the radio spectrum is dominated by the average over the inhomogeneities within the shock, with most of the emission coming from the tail of the Mach number distribution. In contrast to the Toothbrush, the spectra of the fainter relics show a high-frequency steepening. Moreover, the integrated spectrum of the halo also follows a power law from 150 MHz to 3 GHz with a spectral index of −1.16 ± 0.04. We do not find any evidence for spectral curvature, not even in subareas of the halo. This suggest a homogeneous acceleration throughout the cluster volume. Between the “brush” region of the Toothbrush and the halo, the color-color analysis reveals emission that was consistent with an overlap between the two different spectral regions.

Conclusions.None of the relic structures, that is, the Toothbrush as a whole or its subregions or the other two fainter relics, show spectral shapes consistent with a single injection of relativistic electrons, such as at a shock, followed by synchrotron aging in a relatively homogeneous environment. Inhomogeneities in some combination of Mach number, magnetic field strength, and projection effects dominate the observed spectral shapes.
Observational and theoretical constraints on the formation and early evolution of the first dust grains in galaxies at 5 < z < 10
Authors: Burgarella D. , Nanni A. , Hirashita H. , Theulé P. , Inoue A. K. , Takeuchi T. T.
Published: March 2020

Context. The first generation of stars were born a few hundred million years after the big bang. These stars synthesise elements heavier than H and He, which are later expelled into the interstellar medium, initiating the rise of metals. Within this enriched medium, the first dust grains were formed. This event is cosmologically crucial for molecule formation, as dust plays a major role by cooling low-metallicity star-forming clouds, which can fragment to create lower mass stars. Collecting information on these first dust grains is difficult because of the negative alliance of large distances and low dust masses.

Aims. We aim to combine the observational information from galaxies at redshifts 5 ≲ z ≲ 10 to constrain their dust emission and theoretically understand the first evolutionary phases of the dust cycle.

Methods. Spectral energy distributions (SEDs) are fitted with CIGALE and the physical parameters and their evolution are modelled. From this SED fitting, we built a dust-emission template for this population of galaxies in the reionisation epoch.

Results. Our new models explain why some early galaxies are observed and others are not. We follow in time the formation of the first grains by supernovae later destroyed by other supernova blasts and expelled in the circumgalactic and intergalactic media.

Conclusions. We find evidence for the first dust grains formed in the universe. But above all, this work underlines the need to collect more data and to develop new facilities to further constrain the dust cycle in galaxies in the reionisation epoch.
PACO ASDI: an algorithm for exoplanet detection and characterization in direct imaging with integral field spectrographs
Authors: Flasseur Olivier , Denis Loïc , Thiébaut Éric , Langlois Maud
Published: March 2020

Context.Exoplanet detection and characterization by direct imaging both rely on sophisticated instruments (adaptive optics and coronagraph) and adequate data processing methods. Angular and spectral differential imaging (ASDI) combines observations at different times and a range of wavelengths in order to separate the residual signal from the host star and the signal of interest corresponding to off-axis sources.

Aims.Very high contrast detection is only possible with an accurate modeling of those two components, in particular of the background due to stellar leakages of the host star masked out by the coronagraph. Beyond the detection of point-like sources in the field of view, it is also essential to characterize the detection in terms of statistical significance and astrometry and to estimate the source spectrum.

Methods.We extend our recent methodPACO, based on local learning of patch covariances, in order to capture the spectral and temporal fluctuations of background structures. From this statistical modeling, we build a detection algorithm and a spectrum estimation method:PACO ASDI. The modeling of spectral correlations proves useful both in reducing detection artifacts and obtaining accurate statistical guarantees (detection thresholds and photometry confidence intervals).

Results.An analysis of several ASDI datasets from the VLT/SPHERE-IFS instrument shows thatPACO ASDIproduces very clean detection maps, for which setting a detection threshold is statistically reliable. Compared to other algorithms used routinely to exploit the scientific results of SPHERE-IFS, sensitivity is improved and many false detections can be avoided. Spectrally smoothed spectra are also produced byPACO ASDI. The analysis of datasets with injected fake planets validates the recovered spectra and the computed confidence intervals.

Conclusions.PACO ASDIis a high-contrast processing algorithm accounting for the spatio-spectral correlations of the data to produce statistically-grounded detection maps and reliable spectral estimations. Point source detections, photometric and astrometric characterizations are fully automatized.
Inclusion of Van der Waals Interactions in DFT using Wannier Functions without empirical parameters
Authors: Silvestrelli Pier Luigi , Ambrosetti Alberto
Published: March 2020

We describe a method for including van der Waals (vdW) interactions in Density Functional Theory (DFT) using the Maximally-Localized Wannier functions (MLWFs), which is free from empirical parameters. With respect to the previous DFT/vdW-WF2 version, in the present DFT/vdW-WF2-x approach, the empirical, short-range, damping function is replaced by an estimate of the Pauli exchange repulsion, also obtained by the MLWFs properties. Applications to systems contained in the popular S22 molecular database and to the case of adsorption of Ar on graphite, and Xe and water on graphene, indicate that the new method, besides being more physically founded, also leads to a systematic improvement in the description of systems where vdW interactions play a significant role.
Newly constructed compact accelerator-based neutron facility at AIST
Authors: Kino Koichi , Fujiwara Takeshi , Furusaka Michihiro , Hayashizaki Noriyosu , Kato Hidetoshi , Kuroda Ryunosuke , Michishio Koji , Muroga Takemi , Ogawa Hiroshi , O'Rourke Brian E. , Oshima Nagayasu , Satoh Daisuke , Sei Norihiro , Shishido Tamao , Suzuki Ryoichi , Tanaka Masahito , Tomota Yo , Toyokawa Hiroyuki , Watazu Akira , Furukawa Kazuro , Nigorikawa Kazuyuki , Obina Takashi
Published: March 2020

We have constructed a compact accelerator-based neutron facility at the National Institute of Advanced Industrial Science and Technology (AIST) in Japan aiming at development of structural materials of transportation vehicles for weight reduction. The facility consists of electron linear accelerator, neutron source, and a neutron beamline with a measurement hutch. Currently we are commissioning the accelerator and expecting a first neutron beam in 2019.
Slab geometry type cold neutron moderator development based on neutronic study for Riken Accelerator-driven compact Neutron Source (RANS)
Authors: Ma Baolong , Ikeda Yujiro , Otake Yoshie , Teshigawara Makoto , Wakabayashi Yasuo , Harada Masahide , Ooi Motoki , Hashiguchi Takao , Yamagata Yutaka , Takeda Shin
Published: March 2020

Cold neutrons with energy less than several meV are good probes for material research, and they have been available on large neutron facilities, whereas it is not commonly available on compact accelerator-driven neutron source. RIKEN Accelerator-driven Neutron Source (RANS) is a pulsed neutron facility which provides thermal neutrons and high energy neutrons at several MeV. We started a project to implement a cold neutron moderator for RANS to broaden cold neutrons applications. A cold neutron moderator system with a mesitylene moderator at 20K and a polyethylene pre-moderator at room temperature in the slab geometry was designed for RANS. So far, the thickness of the pre-moderator and mesitylene have been optimized to get the highest cold neutron flux by using a Monte Carlo simulation code, PHITS. Graphite reflector dimensions were also proven to have significant effect to increase the cold neutron intensity.
Scalable Neutron Imaging Systems at Compact Sources
Authors: Thomsen Knud , Lehmann Eberhard , Strobl Markus
Published: March 2020

Neutron imaging offers unique capabilities not limited to the structural characterisation of materials, components and processes at a large variety of neutron sources and thus is highly qualified to be a prime candidate for instrumentation at compact neutron sources. The peculiar characteristics of neutrons, and in particular the cross sections for their interaction with matter enable imaging results that are directly comparable but, most notably, are effectively complementary to those of wide spread X-ray imaging characterisation. Here, it is highlighted how neutron imaging can significantly add to the value and the versatility of basically all and especially future compact neutron sources. Diverse advantages are identified at all possible sizes and levels of sophistication of compact sources. These areas range from source characterisation and students training to state of the art neutron imaging in 3D to applications and method development, which are possible at compact sources and some of which can take particular advantage of advanced source characteristics such as e.g. several target stations at a single accelerator.
Hybrid boron-10 gaseous detector for slow and fast neutron simultaneous detection
Authors: Potashev Stanislav , Drachev Aleksandr , Burmistrov Yury , Karaevsky Sergey , Kasparov Aleksandr , Ponomarev Vasily , Solodukhov Gennady
Published: March 2020

A hybrid position-sensitive neutron detector with active 10B-layer and proportional chamber filled by the gas mixture Ar+25%CO2 is being studied. The detector is used on the neutron source based at the linear accelerator. Recording two pairs of pulse heights which are produced in two gas gaps by 7Li and 4He nuclei between the anode and two cathodes gives a possibility to determine the X and Y neutron coordinates. This detector permits time-of-flight measurements. A significant difference in pulse height spectra for slow and fast (several MeV) neutrons was observed in experiment. In recent experiments with 10B-detector we found that (1) the pulse heights depend on the neutron energy and (2) the position of the maximum in the pulse height spectrum varies monotonically versus the maximum neutron energy.
DGHO 2019: Cannabinol und Tumorkachexie
Authors: Bubenzer Rainer
Published: March 2020

Der Marihuanamarkt entwickelt sich in vielen Staaten der Welt zu einer der am schnellsten wachsenden Konsumindustrien überhaupt. Parallel zu den meist zweistelligen Marktzuwächsen – beispielsweise in Kanada oder in den USA – boomt auch der Markt für medizinisch eingesetzte Inhaltsstoffe der Heilpflanze Cannabis sativa L. (Hanf, Marihuana).
Internistische Standardmedikamente in der Onkologie
Authors: Bubenzer Rainer
Published: March 2020

Niedergelassene Onkologen werden – jenseits der kurativen Akutmedizin – zu den Hausärzten vieler Krebspatienten. Sei es beim Management von Spätfolgen onkologischer Therapien, sei es bei der Versorgung der wachsenden Zahl chronisch Krebskranker oder sei es bei der palliativmedizinischen Begleitung Sterbender. Dabei stehen im Mittelpunkt der Pharmakotherapie einige zentral bedeutende Präparate wie Protonenpumpeninhibitoren (PPI), Glukokortikoide oder Metamizol, zu denen Prof. Karin Jordan, Heidelberg, bei der DGHO-Jahrestagung 2019 ein Update gab. In jedem Fall sei vor deren Einsatz im Behandlungsalltag die Frage nach der medizinischen Notwendigkeit zu stellen, so ihre zentrale Botschaft.
ECC 2019: Lokal fortgeschrittenes Kolonkarzinom
Authors: Heim Thomas M.
Published: March 2020

FOxTROT (Fluoropyrimidine Oxaliplatin and Targeted Receptor Pre-Operative Therapy) ist eine Schlüsselstudie zur Evaluation neoadjuvanter Chemotherapie bei Patienten mit lokal fortgeschrittenem Kolonkarzinom. Prof. Dion Morton, Birmingham/Großbritannien und Prof. Philip Quirke, Leeds/Großbritannien, waren beide maßgeblich an der Durchführung und Auswertung der Studie beteiligt. Nachdem ein Teil der finalen Ergebnisse bereits im Frühjahr auf dem ASCO-Kongress vorgestellt wurde, warteten die beiden Experten im Dezember 2019 auf dem European Colorectal Congress in St. Gallen mit vertieften Analysen und Schlussfolgerungen auf.
ASH 2019: Akute lymphatische Leukämie
Authors: Schmale Ine
Published: March 2020

Die Tiefe des Ansprechens, definiert durch die minimale Resterkrankung (MRD), erreicht innerhalb der hämatologischen malignen Erkrankungen einen immer höheren Stellenwert und wurde vielfach beim vergangenen ASH diskutiert. Sie ist auch ein Prädiktor für die Prognose von Patienten mit Philadelphia- Chromosom-positiver (Ph +) akuter lymphatischer Leukämie (ALL), wie in Orlando Ende 2019 gezeigt wurde. Eine Vertiefung der MRD wurde bei pädiatrischen B-ALL-Patienten mit dem neuen Standard Blinatumomab erreicht.
Im Gedenken an Professor Dr. med. Ludwig Gortner
Authors: Meyer Sascha , Zemlin Michael
Published: March 2020

Herr Professor Dr. med. Ludwig Gortner, geboren 1950 in Pirmasens, hat sein
berufliches Leben 40 Jahre lang in den Dienst an kranken Früh- und
Neugeborenen, Kindern und Jugendlichen gestellt.
Severe Gingival Recession Caused by Traumatic Occlusion and Mucogingival Stress: A Case Report
Authors: Ustun Kemal , Sari Zafer , Orucoglu Hasan , Duran Ismetdir , Hakki Sema S
Published: March 2020

Gingival recession is displacement of the soft tissue margin apically leading to root surface exposure. Tooth malpositions, high muscle attachment, frenal pull have been associated with gingival tissue recession. Occlusal trauma is defined as injury resulting in tissue changes within the attachment apparatus as a result of occlusal forces. Trauma from occlusion may cause a shift in tooth position and the direction of the movement depends on the occlusal force. We present the clinical and radiological findings and the limitation of periodontal treatment of a severe gingival recession in a case with traumatic occlusion. A 16 years old male, systemically healthy and nonsmoking patient presented to our clinic with severe gingival recession of mandibular canines and incisors. Clinical evaluation revealed extensive gingival recession on the vestibules of mandibular anterior segment. Patient has an Angle class III malocclusion and deep bite. To maintain the teeth until orthodontic therapy and maxillofacial surgery, mucogingival surgeries were performed to obtain attached gingiva to provide oral hygiene and reduce inflammation. After mucogingival surgeries, limited attached gingiva was gained in this case. Regular periodontal maintenance therapy was performed at 2 month intervals to preserve mandibular anterior teeth. Multidisciplinary approach should be performed in this kind of case for satisfactory results. Unless occlusal relationship was corrected, treatment of severe gingival recession will be problematic. For satisfactory periodontal treatment, early diagnosis of trauma from occlusion and its treatment is very important. (Eur J Dent 2008;2:127-133)
Factor-based investing in government bond markets: a survey of the current state of research
Authors: Bektić Demir , Hachenberg Britta , Schiereck Dirk
Published: March 2020

Factor investing has become very popular during the last decades, especially with respect to equity markets. After extending Fama–French factors to corporate bond markets, recent research more often concentrates on the government bond space and reveals that there is indeed clear empirical evidence for the existence of significant government bond factors. Voices that state the opposite refer to outdated data samples. By the documentation of rather homogeneous recent empirical evidence, this review underlines the attractiveness of more sophisticated investment approaches, which are well established in equity and even in corporate bond markets, to the segment of government bonds.
Fractional bosonic strings
Authors: Diaz Victor Alfonzo , Giusti Andrea
Published: March 2020

The aim of this paper is to present a simple generalization of bosonic string theory in the framework of the theory of fractional variational problems. Specifically, we present a fractional extension of the Polyakov action, for which we compute the general form of the equations of motion and discuss the connection between the new fractional action and a generalization the Nambu-Goto action. Consequently, we analyze the symmetries of the modified Polyakov action and try to fix the gauge, following the classical procedures. Then we solve the equations of motion in a simplified setting. Finally, we present a Hamiltonian description of the classical fractional bosonic string and introduce the fractional light-cone gauge. It is important to remark that, throughout the whole paper, we thoroughly discuss how to recover the known results as an “integer” limit of the presented model.
Polysulfone shock compressed above the decomposition threshold: Velocimetry and modeling of two-wave structures
Authors: Huber R. C. , Peterson J. , Coe Joshua D. , Dattelbaum D. M. , Gibson L. L. , Gustavsen R. L. , Lang J. M. , Sheffield S. A.
Published: March 2020

Polysulfone was shock loaded to pressures of 14.6–26.2 GPa in a series of gas gun-driven plate-impact experiments measuring material response with embedded electro-magnetic particle velocity gauges and optical velocimetry. The embedded electro-magnetic particle velocity gauges did not show a distinct two-wave structure but did show rounding that suggested a reaction but not a distinct separation of the reactants and product waves. In contrast, the transmission experiments fielded with optical velocimetry, with product pressures ranging from 21.0 to 26.2 GPa, showed well-defined two-wave structures due to shock-driven chemical decomposition of the polymer to products at a higher density. Distinct two-wave structures have not previously been published in literature during polymer compression; here, we observed these two-wave structures at both the polymer/lithium fluoride and polymer/polymethylmethacrylate interfaces. Hydrodynamic simulations of the experiments were performed using a newly constructed SESAME equation of state (EOS) for the polymer, a thermochemical EOS for the decomposition products, and an Arrhenius reaction rate model for the kinetics of the reaction. Simulation results also demonstrated two-wave structures but were unable to quantitatively reproduce either the embedded gauge or optical velocimetry data.
Scaling behavior of dynamic ferroelectric hysteresis for semiconductor–relaxor (0–3) type ZnO-(Bi0.5Na0.5)0.94Ba0.06TiO3 composite
Authors: Pradhan Lagen Kumar , Kar Manoranjan
Published: March 2020

Currently, semiconductor–relaxor ferroelectric (0–3) type composites are promising lead-free ferroelectric candidates for high-temperature piezoelectric applications. Among all, 0.30(ZnO)-0.70[(Bi0.5Na0.5)0.94Ba0.06TiO3] is one of the most studied composites by researchers. Therefore, to understand the role of ZnO on the polarization reversal process and domain states of (Bi0.5Na0.5)0.94Ba0.06TiO3, the dynamic ferroelectric hysteresis of the present composite has been investigated as a function of electric field amplitude (E0) and frequency (f). According to the power law, a set of scaling relations between the loop area ⟨A⟩ with E0 and f have been established for minor and saturated loops, which take the form of ⟨A⟩∝f−0.389E04.586 and ⟨A⟩∝f−0.021E01.066, respectively. Also, it is interesting to note that the frequency-dependent ferroelectric hysteresis loops [for the saturated field (E0) = 50 kV/cm] exhibit the unique two-stage scaling behavior. Additionally, the origin of enhancement in the domain switching process for minor loop regions has been correlated with the presence of a semiconductor (ZnO), which is extensively discussed in the present study.
Enhancement of the second harmonic signal of nonlinear crystals by self-assembled gold nanoparticles
Authors: Gürdal Emre , Horneber Anke , Shaqqura Nadim , Meixner Alfred J. , Kern Dieter P. , Zhang Dai , Fleischer Monika
Published: March 2020

In second harmonic generation (SHG), the energy of two incoming photons, e.g., from a femtosecond laser, can be combined in one outgoing photon of twice the energy, e.g., by means of a nonlinear crystal. The SHG efficiency, however, is limited. In this work, the harvested signal is maximized by composing a hybrid system consisting of a nonlinear crystal with a dense coverage of plasmonic nanostructures separated by narrow gaps. The method of self-assembled diblock-copolymer-based micellar lithography with subsequent electroless deposition is employed to cover the whole surface of a lithium niobate (LiNbO3) crystal. The interaction of plasmonic nanostructures with light leads to a strong electric near-field in the adjacent crystal. This near-field is harnessed to enhance the near-surface SHG signal from the nonlinear crystal. At the plasmon resonance of the gold nanoparticles, a pronounced enhancement of about 60-fold SHG is observed compared to the bare crystal within the confocal volume of a laser spot.
Anharmonic calculations of vibrational spectra for molecular adsorbates: A divide-and-conquer semiclassical molecular dynamics approach
Authors: Cazzaniga Marco , Micciarelli Marco , Moriggi Francesco , Mahmoud Agnes , Gabas Fabio , Ceotto Michele
Published: March 2020

The vibrational spectroscopy of adsorbates is becoming an important investigation tool for catalysis and material science. This paper presents a semiclassical molecular dynamics method able to reproduce the vibrational energy levels of systems composed by molecules adsorbed on solid surfaces. Specifically, we extend our divide-and-conquer semiclassical method for power spectra calculations to gas-surface systems and interface it with plane-wave electronic structure codes. The Born–Oppenheimer classical dynamics underlying the semiclassical calculation is full dimensional, and our method includes not only the motion of the adsorbate but also those of the surface and the bulk. The vibrational spectroscopic peaks related to the adsorbate are accounted together with the most coupled phonon modes to obtain spectra amenable to physical interpretations. We apply the method to the adsorption of CO, NO, and H2O on the anatase-TiO2 (101) surface. We compare our semiclassical results with the single-point harmonic estimates and the classical power spectra obtained from the same trajectory employed in the semiclassical calculation. We find that CO and NO anharmonic effects of fundamental vibrations are similarly reproduced by the classical and semiclassical dynamics and that H2O adsorption is fully and properly described in its overtone and combination band relevant components only by the semiclassical approach.
An infrared transmission study of Ge:Mn thick films prepared by ion implantation and post-annealing
Authors: Obied L. H. , Roorda S. , Prucnal S. , Zhou Shengqiang , Crandles D. A.
Published: March 2020

Ge:Mn thick films (t≈3 μm) with low average Mn concentration (<0.3%) were prepared by ion implantation at 77 K followed by either conventional or flashlamp annealing. The films were characterized by x-ray diffraction, secondary ion mass spectrometry, magnetometry, and infrared transmission (100–6500 cm−1). Post-annealing at a high enough temperature recrystallizes the amorphous Ge:Mn films without significant migration of Mn to the surface, while solid phase epitaxy does not occur, resulting in polycrystalline films. Annealing causes an estimated 50%–80% of the implanted Mn to migrate to Mn-rich clusters or form Mn5Ge3, while the remainder enters the Ge lattice substitutionally creating free holes. Evidence for free holes comes from the structure in the mid-infrared absorption coefficient that is similar to previous observations in p-type Ge. The data suggest that the maximum solubility of Mn in the Ge crystalline lattice has an upper limit of <0.08%.
Quantitative study on the mechanisms underlying the phonon bottleneck effect in InN/InGaN multiple quantum wells
Authors: Zhang Yi , Tang Liangliang , Zhang Bo , Wang Pei , Xu Chang
Published: March 2020

Herein, we quantitatively investigated the mechanisms of interfacial phonon mismatch and quantum confinement underlying the phonon bottleneck effect in InN/InxGa(1−x)N multiple quantum wells. Obvious extension of carrier thermalization with the longest relaxation time of 4.75 ns due to an enhanced phonon bottleneck effect was observed. It was found that a stronger quantum confinement could effectively reduce carrier relaxation rate via improving the elastic carrier–carrier scattering, while a larger phonon mismatch may give a higher initial carrier temperature due to the reflection of optical phonons and probably confinement of quasi-optical phonons. This study provides an essential theoretical insight into photovoltaic and other optoelectronic devices aiming to reduce the carrier relaxation rate via the phonon bottleneck effect.