bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor collagen framework from bright-field histology images predicts overall survival of breast carcinoma patients
Authors: Morkunas Mindaugas , Zilenaite Dovile , Laurinaviciene Aida , Treigys Povilas , Laurinavicius Arvydas
Published: July 2021

Within the tumor microenvironment, specifically aligned collagen has been shown to stimulate tumor progression by directing the migration of metastatic cells along its structural framework. Tumor-associated collagen signatures (TACS) have been linked to breast cancer patient outcome. Robust and affordable methods for assessing biological information contained in collagen architecture need to be developed. We have developed a novel artificial neural network (ANN) based approach for tumor collagen segmentation from bright-field histology images and have tested it on a set of tissue microarray sections from early hormone receptor-positive invasive ductal breast carcinoma stained with Sirius Red (1 core per patient, n = 92). We designed and trained ANNs on sets of differently annotated image patches to segment collagen fibers and extracted 37 features of collagen fiber morphometry, density, orientation, texture, and fractal characteristics in the entire cohort. Independent instances of ANN models trained on highly differing annotations produced reasonably concordant collagen segmentation masks and allowed reliable prognostic Cox regression models (with likelihood ratios 14.11–22.99, at p-value < 0.05) superior to conventional clinical parameters (size of the primary tumor (T), regional lymph node status (N), histological grade (G), and patient age). Additionally, we noted statistically significant differences of collagen features between tumor grade groups, and the factor analysis revealed features resembling the TACS concept. Our proposed method offers collagen framework segmentation from bright-field histology images and provides novel image-based features for better breast cancer patient prognostication.
Dynamic selective auditory attention detection using RNN and reinforcement learning
Authors: Geravanchizadeh Masoud , Roushan Hossein
Published: July 2021

The cocktail party phenomenon describes the ability of the human brain to focus auditory attention on a particular stimulus while ignoring other acoustic events. Selective auditory attention detection (SAAD) is an important issue in the development of brain-computer interface systems and cocktail party processors. This paper proposes a new dynamic attention detection system to process the temporal evolution of the input signal. The proposed dynamic SAAD is modeled as a sequential decision-making problem, which is solved by recurrent neural network (RNN) and reinforcement learning methods of Q-learning and deep Q-learning. Among different dynamic learning approaches, the evaluation results show that the deep Q-learning approach with RNN as agent provides the highest classification accuracy (94.2%) with the least detection delay. The proposed SAAD system is advantageous, in the sense that the detection of attention is performed dynamically for the sequential inputs. Also, the system has the potential to be used in scenarios, where the attention of the listener might be switched in time in the presence of various acoustic events.
Imaging multiple sclerosis pathology at 160 μm isotropic resolution by human whole-brain ex vivo magnetic resonance imaging at 3 T
Authors: Weigel Matthias , Dechent Peter , Galbusera Riccardo , Bahn Erik , Nair Govind , Lu Po-Jui , Kappos Ludwig , Brück Wolfgang , Stadelmann Christine , Granziera Cristina
Published: July 2021

Postmortem magnetic resonance imaging (MRI) of the fixed healthy and diseased human brain facilitates spatial resolutions and image quality that is not achievable with in vivo MRI scans. Though challenging—and almost exclusively performed at 7 T field strength—depicting the tissue architecture of the entire brain in fine detail is invaluable since it enables the study of neuroanatomy and uncovers important pathological features in neurological disorders. The objectives of the present work were (1) to develop a 3D isotropic ultra-high-resolution imaging approach for human whole-brain ex vivo acquisitions working on a standard clinical 3 T MRI system; and (2) to explore the sensitivity and specificity of this concept for specific pathoanatomical features of multiple sclerosis. The reconstructed images demonstrate unprecedented resolution and soft tissue contrast of the diseased human brain at 3 T, thus allowing visualization of sub-millimetric lesions in the different cortical layers and in the cerebellar cortex, as well as unique cortical lesion characteristics such as the presence of incomplete/complete iron rims, and patterns of iron accumulation. Further details such as the subpial molecular layer, the line of Gennari, and some intrathalamic nuclei are also well distinguishable.
Synthesis, antioxidant and cytoprotective activity evaluation of C-3 substituted indole derivatives
Authors: Jasiewicz Beata , Kozanecka-Okupnik Weronika , Przygodzki Michał , Warżajtis Beata , Rychlewska Urszula , Pospieszny Tomasz , Mrówczyńska Lucyna
Published: July 2021

A series of fifteen indole derivatives substituted at the C-3 position were synthesized and characterized. The antioxidant activity of all derivatives was investigated by three in vitro antioxidant assays, and the derivative with pyrrolidinedithiocarbamate moiety was the most active as a radical scavenger and Fe3+-Fe2+ reducer. It can be stated that possible hydrogen and electron transfer mechanism is suggested for the quenching of the free radical. Moreover, the indolyl radical stabilization and the presence of unsubstituted indole nitrogen atom are mandatory for the observed antioxidant activity, which strongly depends on the type of the substituent directly connected to the methylene group at the C-3 position. Human red blood cells (RBC) have been used as a cell model to study derivatives interaction with the cell membrane. Haemolytic activity and RBC shape transformation were observed for certain derivatives in a concentration-dependent manner. However, most of the derivatives at sublytic concentration showed high cytoprotective activity against oxidative haemolysis induced by 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH). The cytoprotective properties of derivatives can be explained mostly due to their interactions with the RBC membrane components. Taking together, theoretical estimations and experimental data confirm the beneficial interactions between the selected C-3 substituted indole derivatives and the RBC membrane under oxidative stress conditions. These results encourage us to further structural optimization of C-3 substituted indole derivatives as potent antioxidant compounds.
Neurotranscriptomic changes associated with chick-directed parental care in adult non-reproductive Japanese quail
Authors: Lopes Patricia C. , de Bruijn Robert
Published: July 2021

For many species, parental care critically affects offspring survival. But what drives animals to display parental behaviours towards young? In mammals, pregnancy-induced physiological transformations seem key in preparing the neural circuits that lead towards attraction (and reduced-aggression) to young. Beyond mammalian maternal behaviour, knowledge of the neural mechanisms that underlie young-directed parental care is severely lacking. We took advantage of a domesticated bird species, the Japanese quail, for which parental behaviour towards chicks can be induced in virgin non-reproductive adults through a sensitization procedure, a process that is not effective in all animals. We used the variation in parental responses to study neural transcriptomic changes associated with the sensitization procedure itself and with the outcome of the procedure (i.e., presence of parental behaviours). We found differences in gene expression in the hypothalamus and bed nucleus of the stria terminalis, but not the nucleus taeniae. Two genes identified are of particular interest. One is neurotensin, previously only demonstrated to be causally associated with maternal care in mammals. The other one is urocortin 3, causally demonstrated to affect young-directed neglect and aggression in mammals. Because our studies were conducted in animals that were reproductively quiescent, our results reflect core neural changes that may be associated with avian young-directed care independently of extensive hormonal stimulation. Our work opens new avenues of research into understanding the neural basis of parental care in non-placental species.
Study on landslide susceptibility mapping based on rock–soil characteristic factors
Authors: Yu Xianyu , Zhang Kaixiang , Song Yingxu , Jiang Weiwei , Zhou Jianguo
Published: July 2021

This study introduces four rock–soil characteristics factors, that is, Lithology, Rock Structure, Rock Infiltration, and Rock Weathering, which based on the properties of rock formations, to predict Landslide Susceptibility Mapping (LSM) in Three Gorges Reservoir Area from Zigui to Badong. Logistic regression, artificial neural network, support vector machine is used in LSM modeling. The study consists of three main steps. In the first step, these four factors are combined with the 11 basic factors to form different factor combinations. The second step randomly selects training (70% of the total) and validation (30%) datasets out of grid cells corresponding to landslide and non-landslide locations in the study area. The final step constructs the LSM models to obtain different landslide susceptibility index maps and landslide susceptibility zoning maps. The specific category precision, receiver operating characteristic curve, and 5 other statistical evaluation methods are used for quantitative evaluations. The evaluation results show that, in most cases, the result based on Rock Structure are better than the result obtained by traditional method based on Lithology, have the best performance. To further study the influence of rock–soil characteristic factors on the LSM, these four factors are divided into “Intrinsic attribute factors” and “External participation factors” in accordance with the participation of external factors, to generate the LSMs. The evaluation results show that the result based on Intrinsic attribute factors are better than the result based on External participation factors, indicating the significance of Intrinsic attribute factors in LSM. The method proposed in this study can effectively improve the scientificity, accuracy, and validity of LSM.
A theoretical framework for general design of two-materials composed diffractive fresnel lens
Authors: Lin Ming-Yen , Chuang Chih-Hao , Chou Tzu-An , Chen Chien-Yu
Published: July 2021

Near 100% of diffractive efficiency for diffractive optical elements (DOEs) is one of the most required optical performances in broadband imaging applications. Of all flat DOEs, none seems to interest researchers as much as Two-Materials Composed Diffractive Fresnel Lens (TM-DFL) among the most promising flat DOEs. An approach of the near 100% of diffractive efficiency for TM-DFL once developed to determine the design rules mainly takes the advantage of numerical computation by methods of mapping and fitting. Despite a curved line of near 100% of diffractive efficiency can be generated in the Abbe and partial dispersion diagram, it is not able to analytically elaborate the relationship between two optical materials that compose the TM-DFL. Here, we present a theoretical framework, based on the fundaments of Cauchy's equation, Abbe number, partial dispersion, and the diffraction theory of Fresnel lens, for obtaining a general design formalism, so to perform the perfect material matching between two different optical materials for achieving the near 100% of diffractive efficiency for TM-DFL in the broadband imaging applications.
Response of compacted bentonite to hyperalkalinity and thermal history
Authors: Kale Rohini C. , Kapil Bhanwariwal , Ravi K.
Published: July 2021

The use of compacted bentonite around the high-level nuclear waste canister (HLW) inside the deep geological repository (DGR) ensures the prevention of entry of active radionuclides in the atmosphere due to its noteworthy large swelling ability. In the eventual repository, the waste canister has a high (100 °C–200 °C) temperature initially, and it reduces over a vast period, which induces a thermal history over the compacted bentonite layer. The cement/concrete layer is constructed as a bulkhead or in the vaults or to support the access of galleries between a buffer and the host rock, and it degrades over the period. The hyperalkaline fluid is created when it percolates through the cement/concrete layer and comes in contact with the compacted bentonite. The contact of hyperalkaline fluid to compacted bentonite induced with thermal history can hamper the swell pressure characteristic of the bentonite. Therefore to determine the combined effect of hyperalkalinity to the thermal history induced compacted bentonite, swell pressure testing has been conducted on two compacted Barmer bentonites (B1 and B2) specimens with an initial dry density of 1.5 Mg/m3, 1.75 Mg/m3, and 2.0 Mg/m3 and saturated with distilled water as well as with hyperalkaline cement water (W/C = 1 und pH = 12.5) and heated to 110 °C and 200 °C. When the specimens were saturated with hyperalkaline cement water, the swell pressure exerted by both bentonites was noticeably reduced compared to specimens saturated with distilled water. Nevertheless, the time taken to full saturation was longer than distilled water for samples saturated with hyperalkaline cement water. Also, the decrease in swell pressure was observed in the samples subjected to thermal history than samples, which were tested without inducing thermal history in both the cases of hyperalkaline cement water and distilled water. The microstructural observations through XRD, FESEM and EDX revealed the clogging of pores due to the presence of non-swelling minerals.
In vitro monitoring of HTR2A-positive neurons derived from human-induced pluripotent stem cells
Authors: Nakai Kento , Shiga Takahiro , Yasuhara Rika , Sarkar Avijite Kumer , Abe Yuka , Nakamura Shiro , Hoashi Yurie , Kotani Keisuke , Tatsumoto Shoji , Ishikawa Hiroe , Go Yasuhiro , Inoue Tomio , Mishima Kenji , Akamatsu Wado , Baba Kazuyoshi
Published: July 2021

The serotonin 5-HT2A receptor (5-HT2AR) has been receiving increasing attention because its genetic variants have been associated with a variety of neurological diseases. To elucidate the pathogenesis of the neurological diseases associated with 5-HT2AR gene (HTR2A) variants, we have previously established a protocol to induce HTR2A-expressing neurons from human-induced pluripotent stem cells (hiPSCs). Here, we investigated the maturation stages and electrophysiological properties of HTR2A-positive neurons induced from hiPSCs and constructed an HTR2A promoter-specific reporter lentivirus to label the neurons. We found that neuronal maturity increased over time and that HTR2A expression was induced at the late stage of neuronal maturation. Furthermore, we demonstrated successful labelling of the HTR2A-positive neurons, which had fluorescence and generated repetitive action potentials in response to depolarizing currents and an inward current during the application of TCB-2, a selective agonist of 5-HT2ARs, respectively. These results indicated that our in vitro model mimicked the in vivo dynamics of 5-HT2AR. Therefore, in vitro monitoring of the function of HTR2A-positive neurons induced from hiPSCs could help elucidate the pathophysiological mechanisms of neurological diseases associated with genetic variations of the HTR2A gene.
Mid-infrared spectral classification of endometrial cancer compared to benign controls in serum or plasma samples
Authors: Mabwa David , Gajjar Ketankumar , Furniss David , Schiemer Roberta , Crane Richard , Fallaize Christopher , Martin-Hirsch Pierre L. , Martin Francis L. , Kypraios Theordore , Seddon Angela B. , Phang Sendy
Published: July 2021

The process for developing an accurate and reliable classification model based on the previously pre-processed data. The performance of each classification model is assessed using the Matthew's Correlation Coefficient as a metric.
Nanoscale metal–organic frameworks for the intracellular delivery of CRISPR/Cas9 genome editing machinery
Authors: Zheng Qizhen , Li Wenting , Mao Lanqun , Wang Ming
Published: July 2021

The discovery of CRISPR/Cas9 genome-editing technology enables the precise manipulation of mammalian DNA sequences for treating genetic disorders.
Dual-sonosensitizer loaded phase-transition nanoparticles with tumor-targeting for synergistically enhanced sonodynamic therapy
Authors: Li Qianru , Lin Xiaohong , Fan Yongzeng , Rao Maohua , Wang Yirui , Wang Mengzhu , Wang Zhigang , Hao Lan , Yuan Gengbiao
Published: July 2021

Sonodynamic therapy (SDT) is a fast-growing therapy activated by using ultrasound to initiate a catalytic reaction of sensitizing agents and kill tumor cells through producing reactive oxygen species (ROS).
A cationic copolymer as a cocatalyst for a peroxidase-mimicking heme-DNAzyme
Authors: Araki Haruka , Hagiwara Shota , Shinomiya Ryosuke , Momotake Atsuya , Kotani Hiroaki , Kojima Takahiko , Ochiai Takuro , Shimada Naohiko , Maruyama Atsushi , Yamamoto Yasuhiko
Published: July 2021

Heme binds to a parallel-stranded G-quadruplex DNA to form a peroxidase-mimicking heme-DNAzyme. We found that a polymer with protonated amino groups can act as a cocatalyst for the heme-DNAzyme in the oxidation catalysis.
A metal–carbene template approach enables efficient synthesis of a functionalized cage-annulated crown ether
Authors: Chang Jin-Ping , Sun Li-Ying , Zhang Zi-En , An Yuan-Yuan , Zhang Le , Yu Jian-Gang , Han Ying-Feng
Published: July 2021

A novel flexible intramolecular cage-annulated crown ether organic imidazolium cation with potentially large cavities was constructed through a kind of post-assembly modification strategy, photochemical [2+2] cycloaddition reaction.
Tunable protein crystal size distribution via continuous slug-flow crystallization with spatially varying temperature
Authors: Mozdzierz Nicholas J. , Hong Moo Sun , Lee Yongkyu , Benisch Moritz H. P. , Jiang Mo , Myerson Allan S. , Braatz Richard D.
Published: July 2021

Under appropriate buffer and pH conditions, the magnitude and dispersion of the product protein crystals were reproducibly manipulated by controlling the spatial temperature along the tube in a continuous tubular crystallizer.
Correction: Toxicokinetics of pristine and aged silver nanoparticles in Physa acuta
Authors: Silva Patrícia V. , van Gestel Cornelis A. M. , Verweij Rudo A. , Papadiamantis Anastasios G. , Gonçalves Sandra F. , Lynch Iseult , Loureiro Susana
Published: July 2021

Correction for ‘Toxicokinetics of pristine and aged silver nanoparticles in Physa acuta’ by Patrícia V. Silva et al., Environ. Sci.: Nano, 2020, 7, 3849–3868, DOI: 10.1039/D0EN00946F.
Peptide lipidation in lysophospholipid micelles and lysophospholipid-enriched membranes
Authors: Ismail Vian S. , Britt Hannah M. , Mosely Jackie A. , Sanderson John M.
Published: July 2021

Acyl transfer to a membrane-associated peptide from both lysolipids and lipids occurs readily, leading to the generation of a lipidated peptide that adopts secondary structure in the absence of lipids.
Amentoflavone inhibits tumor necrosis factor-α-induced migration and invasion through AKT/mTOR/S6k1/hedgehog signaling in human breast cancer
Authors: Qiu Shuai , Zhou Yimeng , Kim Jin Tae , Bao Cheng , Lee Hong Jin , Chen Jing
Published: July 2021

Amentoflavone inhibits the migration and invasion in tumor necrosis factor-α (TNFα) induced breast cancer cells through AKT/mTOR/S6k1/Gli1 axis.
Multiplex recreation of human intestinal morphogenesis on a multi-well insert platform by basolateral convective flow
Authors: Chong Hyeon Beom , Youn Jaeseung , Shin Woojung , Kim Hyun Jung , Kim Dong Sung
Published: July 2021

The basolateral convective flow-generating multi-well insert platform (BASIN).
Nanoscale disintegration kinetics of mesoglobules in aqueous poly(N-isopropylacrylamide) solutions revealed by small-angle neutron scattering and pressure jumps
Authors: Niebuur Bart-Jan , Chiappisi Leonardo , Jung Florian A. , Zhang Xiaohan , Schulte Alfons , Papadakis Christine M.
Published: July 2021

Two types of disintegration processes are revealed for polymeric nanoparticles using rapid pressure jumps and kinetic small-angle neutron scattering, namely chain release or swelling of the nanoparticle, depending on the target pressure.
Recent reports on the synthesis of γ-butenolide, γ-alkylidenebutenolide frameworks, and related natural products
Authors: Chatterjee Shrestha , Sahoo Rajkumar , Nanda Samik
Published: July 2021

This review focusses on synthetic strategies for γ-butenolides from 2010 to 2020 with an emphasis on γ-alkylidenebutenolides and related molecules. Metal-mediated catalytic transformation and organocatalysis are the two main reaction partners that were widely used.
Palladium-catalysed cyclisation of ynamides and propargyl tethered iodosulfonamides with boronic acids leading to benzosultams
Authors: Sandeep K. , Siva Reddy Alla , Kumara Swamy K. C.
Published: July 2021

A convenient route to benzo[d]isothiazole and benzo[e][1,2]thiazine scaffolds using ynamides and arylboronic acids under [Pd]-catalysis is reported; the synthetic utility has been demonstrated by a gram-scale synthesis.
Covalent and non-covalent chemistry of 2D black phosphorus
Authors: Mitrović Aleksandra , Abellán Gonzalo , Hirsch Andreas
Published: July 2021

This review presents novel concepts and strategies on the chemical functionalization of black phosphorus (BP), both non-covalent and covalent, emphazising the current synthetic challenges and providing fundamental insights into the chemistry of BP.
Sulfated zirconium oxide-decorated magnetite KCC-1 as a durable and recyclable adsorbent for the efficient removal of asphaltene from crude oil
Authors: Shaafi Farhad Bohlooli , Motavalizadehkakhky Alireza , Zhiani Rahele , Nouri Seyed Mohammad Mahdi , Hosseiny Malihesadat
Published: July 2021

A new, efficient and recyclable hybrid based on immobilized sulfated zirconium oxide on magnetite fibrous silica (KCC-1) has been developed and utilized for the efficient adsorption and removal of asphaltene from crude oil.
Optimizing the composition of LiFSI-based electrolytes by a method combining simplex with normalization
Authors: Lu Hongli , Zeng Shuangwei , Zhao Dongni , Wang Jie , Quan Yin , Xu Fei , Li Faqiang , Li Shiyou
Published: July 2021

The manuscript addresses that the electrolyte system with five components was optimized by combining the simplex method, normalization and electrochemical testing in lithium-ion batteries. The optimized electrolyte is better than commercial electrolyte LiPF6–EC/DEC.
Silica gel-immobilised chiral 1,2-benzenedisulfonimide: a Brønsted acid heterogeneous catalyst for enantioselective multicomponent Passerini reaction
Authors: Antenucci Achille , Marra Francesco , Dughera Stefano
Published: July 2021

A chiral heterogeneous catalyst derivative of (−)-4,5-dimethyl-3,6-bis(1-naphthyl)-1,2-benzenedisulfonimide is proven here to be efficient in a three-component asymmetric Passerini protocol, carried out in a deep eutectic solvent.
Rotational diffusion and rotational correlations in frictional amorphous disk packings under shear
Authors: Wang Dong , Nejadsadeghi Nima , Li Yan , Shekhar Shashi , Misra Anil , Dijksman Joshua A.
Published: July 2021

Particles in a packing will rotate when the packing is deformed. We find that rotations display diffusive dynamics set by particle friction and packing fraction. Rotations are spatially anticorrelated and directly indicative of the system pressure.
A simulation study on the effect of nanoparticle size on the glass transition temperature of polymer nanocomposites
Authors: Khan Raja Azhar Ashraaf , Qi Hang-Kai , Huang Jian-Hua , Luo Meng-Bo
Published: July 2021

The glass transition temperature (Tg) of polymer nanocomposites is dependent on the size of nanoparticles. The behaviors of the diffusion constant and relaxation time of polymer chains at a temperature above Tg also support the results of Tg.
Targeting the ‘garbage-bin’ to fight cancer: HDAC6 inhibitor WT161 has an anti-tumor effect on osteosarcoma and synergistically interacts with 5-FU
Authors: Sergi Consolato M.
Published: July 2021

An imbalance between protein aggregation and protein degradation may induce ‘stress’ in the functionality of the endoplasmic reticulum (ER). There are quality control (QC) mechanisms to minimize misfolding and to eliminate misfolded proteins before aggregation becomes lethal for the cell. Proper protein folding and maturation is one of the crucial functions of the ER. Chaperones of the ER and folding enzymes guarantee correct conformational maturation of emerging secretory proteins. Histone deacetylase (HDAC) 6 (HDAC6) is a masterpiece coordinating the cell response to protein aggregate formation. The balance between HDAC6 and its partner Valosin-containing protein/p97 determines the fate of polyubiquitinated misfolded proteins. WT161 is a terrific, selective, and bioavailable HDAC6 inhibitor. WT161 selectively inhibits HDAC6 and adequately increases levels of acetylated α-tubulin. This compound induces accumulation of acetylated tubulin and cytotoxicity in multiple myeloma (MM) cells. In this journal, Sun et al. (Biosci. Rep.41, DOI: 10.1042/BSR20203905) identified that WT161 suppresses the cell growth of osteosarcoma cells. This discovery opens the door to future chemotherapeutic regimens of this bone neoplasm.
Co‐teaching based pseudo label refinery for cross‐domain object detection
Authors: Wang Kunpeng , Cai Jingxiang , Yao Juan , Liu Peng , Zhu Zhiqin
Published: July 2021

Object detection is one of the main tasks in computer vision and has made great progress in recent years. However, the performance of target detectors is significantly dropped by the differences between existing datasets and application scenarios, leading to the so‐called domain shift problem. To address such an issue, a novel co‐teaching based pseudo label refinery framework for cross‐domain object detection is developed, which cooperates with two models to select data from target domain for each other. This strategy can effectively purify the predicted pseudo labels and resist noisy labels. Specifically, the framework consists of two encoders (i.e. structure encoder and global encoder), two classifiers and one discriminator, in which structure encoder is used to extract structural features that are not disturbed by colour, and the global encoder is used to extract the complete discriminant features. The two encoders are each followed by a classifier. In training, the structure and global encoder with labelled source samples are first trained, so that it has the initial recognition ability. Then the samples assigned are used with pseudo labels by the classifier following the structure encoder to fine‐tune the global encoder which pre‐trained on the labelled source domain and obtain the refined labels for the target data. With the refined labels, the structure encoder is further optimised on the target domain. During this process, the proposal is to cross use the two classifiers to promote the mutual transfer of complementary capabilities of the two encoders. Moreover, a novel residual channel attention block (RCA) embedded with salient features is designed to pay more attention to the target regions. Extensive experiments demonstrate that the developed framework can generate clean labels for unlabelled target data and boost the performance of cross domain object detection. The code is available at http://www.msp‐lab.cn:1436/msp/cbplr‐master.
Adding ears to intelligent connected vehicles by combining microphone arrays and high definition map
Authors: Jiang Kun , Yang Diange , Wijaya Benny , Zhang Bowei , Yang Mengmeng , Zhang Kai , Tang Xuewei
Published: July 2021

Ears are responsible for the sense of hearing, which is indispensable for a human to understand the environment. It is similar to an intelligent vehicle where acoustical data contains useful and valuable information to comprehend the environment to enable autonomous driving. One important application of acoustical data processing is to localize sound sources. However, due to the complexity of microphone array setup and the unstable localization performance against noises, few research articles tried to localize surrounding vehicles based on on‐board microphone arrays. The main contribution is the first implementation to combine roof‐mounted microphones and high definition maps as vehicle' s ears for online 3D localization of surround vehicles. This article designed a six‐microphones sensor array dedicated to the on‐board application and improved sound source localization algorithms using the observer technique to adapt to dynamic driving scenarios. A map‐based localization enhancement method is also proposed to make the system more robust to noises and model errors. Feasibility tests are conducted with real vehicles in the scenarios of pass‐by and overtaking. Experimental results validate the feasibility of using microphones to localize surrounding vehicles with lane‐level accuracy.
A distributed rule‐based power management strategy in a photovoltaic/hybrid energy storage based on an active compensation filtering technique
Authors: Ghorashi Khalil Abadi Seyyed Ali , Bidram Ali
Published: July 2021

This paper proposes a distributed rule‐based power management strategy for dynamic power balancing and power smoothing in a photovoltaic (PV)/battery‐supercapacitor hybrid energy storage system. The system contains a PV system, a battery‐supercapacitor hybrid energy storage system (HESS), and a group of loads. Firstly, an active compensation technique is proposed which improves the efficiency of the power smoothing filter. Then, a distributed supervisory control technique is employed that prevents the BESS and SC from SOC violation while maintaining the balance between generation and load. To this end, the system components are divided into three different reactive agents including an HESS agent, a PV agent, and a load agent. These agents react to the system changes by switching their operational mode upon satisfying a predefined rule. To analyse the hybrid dynamical behaviour of the agents and design the supervisory controllers, the agents are modelled in hybrid automata frameworks. It is shown that the proposed distributed approach reduces the complexity of the supervisory control system and increases its scalability compared to its equivalent centralized method. Finally, the performance of the proposed approach is validated using a test system simulated in MATLAB/Simulink.
Follow-up of 27 radio-quiet gamma-ray pulsars at 110–190 MHz using the international LOFAR station FR606
Authors: Grießmeier J.-M. , Smith D. A. , Theureau G. , Johnson T. J. , Kerr M. , Bondonneau L. , Cognard I. , Serylak M.
Published: July 2021

Context. The Fermi Large Area Telescope has detected over 260 gamma-ray pulsars. About one quarter of these are labeled as radio-quiet, that is they either have radio flux densities < 30 μJy at 1400 MHz, or they are not detected at all in the radio domain. In the population of nonrecycled gamma-ray pulsars, the fraction of radio-quiet pulsars is higher, about one half.

Aims. Most radio observations of gamma-ray pulsars have been performed at frequencies between 300 MHz and 2 GHz. However, pulsar radio fluxes increase rapidly with decreasing frequency, and their radio beams often broaden at low frequencies. As a consequence, some of these pulsars might be detectable at low radio frequencies even when no radio flux is detected above 300 MHz. Our aim is to test this hypothesis with low-frequency radio observations.

Methods. We have observed 27 Fermi-discovered gamma-ray pulsars with the international LOw Frequency ARray (LOFAR) station FR606 in single-station mode. We used the LOFAR high band antenna band (110−190 MHz), with an average observing time of 13 h per target. Part of the data had to be discarded due to radio frequency interference. On average, we kept 9 h of observation per target after the removal of affected datasets, resulting in a sensitivity for pulse-averaged flux on the order of 1−10 mJy.

Results. We do not detect radio pulsations from any of the 27 sources, and we establish stringent upper limits on their low-frequency radio fluxes. These nondetections are compatible with the upper limits derived from radio observations at other frequencies. We also determine the pulsars’ geometry from the gamma-ray profiles to see for which pulsars the low-frequency radio beam is expected to cross Earth.

Conclusions. This set of observations provides the most constraining upper limits on the flux density at 150 MHz for 27 radio-quiet gamma-ray pulsars. In spite of the beam-widening expected at low radio frequencies, most of our nondetections can be explained by an unfavorable viewing geometry; for the remaining observations, especially those of pulsars detected at higher frequencies, the nondetection is compatible with insufficient sensitivity.
Maximum accretion rate of supermassive stars
Authors: Haemmerlé L. , Klessen R. S. , Mayer L. , Zwick L.
Published: July 2021

Context. The formation of the most massive quasars observed at high redshifts requires extreme inflows of gas down to the length scales of the central compact object.

Aims. Here we estimate the maximum inflow rate allowed by gravity down to the surface of supermassive stars, the possible progenitors of these supermassive black holes.

Methods. We use the continuity equation and the assumption of spherical symmetry and free fall to derive the maximum allowed inflow rates for various density profiles. We apply our approach to the mass–radius relation of rapidly accreting supermassive stars to estimate an upper limit to the accretion rates allowed during the formation of these objects.

Results. We find that, as long as the density of the accreted gas is smaller than or equal to the average density of the accretor, the maximum allowed rate, Ṁmax, is given uniquely by the compactness of the accretor. We argue that a density inversion between accreting matter and the accretor is inconsistent with gravitational collapse. For the compactness of rapidly accreting supermassive stars, Ṁmax is related to the stellar mass, M, by a power law, Ṁmax ∝ M3/4. The rates of atomically cooled halos (0.1−10 M⊙ yr−1) are allowed as soon as M ≳ 1 M⊙. The largest rates expected in galaxy mergers (104 − 105 M⊙ yr−1) become accessible once the accretor is supermassive (M ≳ 104 M⊙).

Conclusions. These results suggest that supermassive stars can accrete up to masses > 106 M⊙ before they collapse via the general-relativistic instability. At such masses, the collapse is expected to lead to the direct formation of a supermassive black hole, even within metal-rich gas, resulting in a black hole seed that is significantly heavier than in conventional direct collapse models for atomic cooling halos.
A type of full multigrid method for non-selfadjoint Steklov eigenvalue problems in inverse scattering
Authors: Xie Manting , Xu Fei , Yue Meiling
Published: July 2021

In this paper, a type of full multigrid method is proposed to solve non-selfadjoint Steklov eigenvalue problems. Multigrid iterations for corresponding selfadjoint and positive definite boundary value problems generate proper iterate solutions that are subsequently added to the coarsest finite element space in order to improve approximate eigenpairs on the current mesh. Based on this full multigrid, we propose a new type of adaptive finite element method for non-selfadjoint Steklov eigenvalue problems. We prove that the computational work of these new schemes are almost optimal, the same as solving the corresponding positive definite selfadjoint boundary value problems. In this case, these type of iteration schemes certainly improve the overfull efficiency of solving the non-selfadjoint Steklov eigenvalue problem. Some numerical examples are provided to validate the theoretical results and the efficiency of this proposed scheme.
Transfer of rare earth to alloy and inclusion during slag-metal reaction
Authors: Gao Xiaoyong , Zhang Lin , Zhang Lifeng , Ren Qiang , Qu Xuanhui
Published: July 2021

Rare earth metal transfer from slag to alloy and inclusion was investigated by slag-metal reaction method. Rare earth oxide (CeO2) employed in the refining slags was used a sample case. The results show that direct application of rare earth oxide in the slag is an alternative to traditional way which uses pure rare earth metal or rare-earth ferrous alloy to add rare earth in an alloy. Slag-metal reaction method proves to be an effective way to improve the rare earth transfer from slags to alloys with high content of Al. The content of Ce in the alloy increased with the increasing CeO2/Al2O3 mass ratio of the slag. As the Ce concentration of molten alloy increased from 0 to 105 ppm, the Al2O3 type inclusion was changed into cerium oxide, cerium sulfide and cerium oxy-sulfide inclusions. In addition, the morphology of inclusions was transformed from irregular to near spherical. Finally, the mechanism was discussed by thermodynamic analysis.
Effects and mechanism of MgO on carbothermal reduction of Fe2TiO4
Authors: Chen Yunfei , Xing Xiangdong
Published: July 2021

The effects of MgO on carbothermal reduction of Fe2TiO4 had been researched including the thermodynamic calculation in this paper. And, based on XRD and SEM-EDS, the effect mechanism of MgO on the direct reduction of Fe2TiO4 had been deeply dissected, systematically. The results showed that magnesium titanium phases including MgTi2O5, MgTiO3 and Mg2TiO4 were formatted after MgO added into Fe2TiO4, which was main reason to affect the reduction of Fe2TiO4. When the MgO content in Fe2TiO4 did not exceed 2%, there was the promoting effect on the reduction of Fe2TiO4. With the increase of MgO content from 2% to 8%, the magnesium titanium phases transformed from MgTi2O5, and through MgTiO3 to Mg2TiO4. The inhibition function appeared, and can be weaken in the high reduction temperature. When reduction temperature reaches to 1300 °C, the metallization rate of F-M-8 (the reduction sample of 8% MgO) can reach 80.62% from 56.43% at 1200 °C. However, the aggregation degree of iron particles became worse when MgO was added to the sample.
Diagnostik und Therapie des Erysipels: Ein Positionspapier der Initiative Chronische Wunden (ICW) e. V.
Authors: Kröger Knut , Schwarzkopf Andreas , Eder Stephan , Protz Kerstin , Münter Christian , Dissemond Joachim
Published: July 2021

Das Erysipel ist eine bakterielle Weichgewebeinfektion, die durch β-hämolysierende Streptokokken verursacht wird und sich entlang der Lymphspalten der Haut nach proximal ausbreitet. Die Eintrittspforten der Erreger können kleinere Verletzungen oder auch chronische Wunden sein. Die Diagnose Erysipel wird klinisch durch die sich ausbreitende Rötung und Überwärmung der Haut, den reduzierten Allgemeinzustand mit Fieber und Schüttelfrost sowie mittels serologischer Entzündungsparameter gestellt und muss von zahlreichen Differenzialdiagnosen abgegrenzt werden. Die systemische Therapie erfolgt meist mit Penicillin. In der Lokaltherapie ist der Stellenwert der Maßnahmen wie Kompressionstherapie oder Kühlung derzeit noch umstritten. Insbesondere für die Rezidivprophylaxe sind die langfristige Therapie des Lymphödems sowie die konsequente Vermeidung und Therapie von Eintrittspforten essenziell.
Der onkologische Nutzen der pelvinen Lymphadenektomie ist beim Prostatakarzinom nicht geklärt
Authors: Weißbach Lothar , Roloff Christiane
Published: July 2021

Der Review von Fossati 2017 stellt den Wert der pLA im Rahmen der RP infrage, weil sich aus den vorliegenden Studien kein onkologischer Nutzen ergibt. Nach wie vor ist die Beweislage wegen fehlender Evidenz dürftig. Unsere Feststellung, dass von metastasierten LK bisher keine Streuung nachgewiesen wurde, basiert auf Registerdaten, auf klinischen Studien ohne Nachweis eines pLA-Vorteils und auf Überlegungen zum genetischen Zusammenhang von LK- und Fernmetastasen. Der Verzicht auf die pLA bzw. auf die Bestrahlung eines Beckenfeldes wird durch die verbesserte Bildgebung mit dem 68Ga-PSMA-PET/CT zum Nachweis von Metastasen erleichtert. Wenn LK nicht metastasieren, wird das Ergebnis der Bildgebung diagnostisch zur Therapieplanung ausreichen. Somit kann auf die pLA aus diagnostischen Gründen verzichtet werden. Komplikationen wären ausgeschlossen. Um die Frage zu klären, ob die pLA bzw. ein multimodales Behandlungskonzept Intermediate- und High-risk-Patienten nützen, wird ein RCT notwendig sein, in dem v. a. der nicht vollständig entfernte Primarius als Streuquelle berücksichtigt wird.
Patterning organic semiconductor crystals for optoelectronics
Authors: Chen Zheng , Duan Shuming , Zhang Xiaotao , Hu Wenping
Published: July 2021

Organic semiconductor crystals (OSCs) present better charge transport characteristics than organic semiconductor films. OSCs have captured worldwide attention because they show great potential for optoelectronic devices, including organic field-effect transistors, active-matrix organic light-emitting diodes, radio frequency identification tags, and sensors. Well-patterned OSCs minimize crosstalk between neighboring devices and decrease leakage current. Therefore, patterning OSCs offers more opportunities for advanced optoelectronic applications. In this work, OSC patterning strategies, advances in applications based on well-patterned OSCs, and challenges and outlooks in the field are discussed.
Pulse area dependence of multiple quantum coherence signals in dilute thermal gases
Authors: Ames Benedikt , Buchleitner Andreas , Carnio Edoardo G. , Shatokhin Vyacheslav N.
Published: July 2021

In the general framework of open quantum systems, we assess the impact of the pulse area on single and double quantum coherence (1QC and 2QC) signals extracted from fluorescence emitted by dilute thermal gases. We show that 1QC and 2QC signals are periodic functions of the pulse area, with distinctive features that reflect the particles’ interactions via photon exchange, the polarizations of the laser pulses, and the observation direction.
Electronic band gap of van der Waals α-As2Te3 crystals
Authors: Khalil Lama , Girard Jean-Christophe , Pierucci Debora , Bisti Federico , Chaste Julien , Oehler Fabrice , Gréboval Charlie , Noumbé Ulrich Nguétchuissi , Dayen Jean-Francois , Logoteta Demetrio , Patriarche Gilles , Rault Julien , Pala Marco , Lhuillier Emmanuel , Ouerghi Abdelkarim
Published: July 2021

van der Waals materials offer a large variety of electronic properties depending on chemical composition, number of layers, and stacking order. Among them, As2Te3 has attracted attention due to the promise of outstanding electronic properties and high photo-response. Precise experimental determinations of the electronic properties of As2Te3 are yet sorely needed for better understanding of potential properties and device applications. Here, we study the structural and electronic properties of α-As2Te3. Scanning transmission electron microscopy coupled to energy x-ray dispersion and micro-Raman spectroscopy all confirm that our specimens correspond to α-As2Te3. Scanning tunneling spectroscopy (STS) at 4.2 K demonstrates that α-As2Te3 exhibits an electronic bandgap of about 0.4 eV. The valence-band maxima are located at −0.03 eV below the Fermi level, thus confirming the residual p-type character of our samples. The material can be exfoliated, revealing the (100) anisotropic surface. Transport measurements on a thick exfoliated sample (bulk-like) confirm the STS results. These findings allow for a deeper understanding of the As2Te3 electronic properties, underlying the potential of V-VI semiconductors for electronic and photonic technologies.
Origin of low-temperature negative transconductance in multilayer MoS2 transistors
Authors: Chen Qi , Li Guoli , Liu Yuan , André Nicolas , Liu Xingqiang , Xia Zhen , Flandre Denis , Liao Lei
Published: July 2021

In this paper, negative transconductance (NTC) behavior in molybdenum disulfides (MoS2) field effect transistors (FETs) is investigated. Combining experimental observation and numerical analysis, we demonstrate that positive shift in the device transfer curves results from the electron trapping/de-trapping processes, where the defect densities at the MoS2/SiO2 interface are reduced when the temperature T decreases from 300 to 200 K. Moreover, the main types of defects that affect the device electrical performance are the interface defect and bulk sulfur vacancy VS in which VS induces the p-type doping effect. While decreasing T below 100 K, NTC occurs when their active layer thickness t (=41 and 35 nm) is larger than the Debye length λ (28 nm). Considering the n-type doping effect induced by the interface defects and the p-type doping caused by the bulk S vacancies, these two opposite doping regions are carefully implemented in simulation at T = 70 K. A vertical barrier induced by the inhomogeneous electron distribution enlarges with the increased gate bias VGS and, thereafter, leads to the unconventional increase in the contact and total resistances with t > λ. While t ≦ λ, the barrier and NTC behavior disappear. The current IDS and transconductance g obtained from the simulation confirm the low-temperature NTC mechanism related to the defects as discussed above. The material defects and physical origin of NTC discussed in the multilayer MoS2 transistors provide the theoretical foundation for designing and realizing novel structures of functional devices via defect engineering in the two-dimensional FET.
A compact optical sensor for explosive detection based on NIR luminescent quantum dots
Authors: Mitri F. , De Iacovo A. , De Santis S. , Giansante C. , Spirito D. , Sotgiu G. , Colace L.
Published: July 2021

Detection of explosive traces in the vapor phase is of primary importance for safety and security in several environments. Different detection methods with high sensitivity are available in the market, but they are typically expensive and require specialized personnel to be operated. Here, we propose a compact, low-cost sensor for explosive detection based on the photoluminescence (PL) quenching of solid-state PbS quantum dot solids cast from the solution phase on a silicon substrate. We demonstrate the sensor capability to detect nitrobenzene vapor at a concentration as low as 445 ppb in air at room temperature, overcoming the performance of other state-of-the-art quantum dot-based PL sensors for nitroaromatic compounds. Moreover, the proposed system can be realized with off-the-shelf electronics and does not need any additional laboratory equipment to be operated, thus paving the way for its deployment in distributed sensor networks.