bluuebunny/crossref_metadata_2025 huggingface dataset:
Acidity and Antioxidant Activity of Cold Brew Coffee
Authors: Rao Niny Z. , Fuller Megan
Published: October 2018

The acidity and antioxidant activity of cold brew coffee were investigated using light roast coffees from Brazil, two regions of Ethiopia, Columbia, Myanmar, and Mexico. The concentrations of three caffeoylquinic acid (CQA) isomers were also determined. Cold brew coffee chemistry was compared to that of hot brew coffee prepared with the same grind-to-coffee ratio. The pH values of the cold and hot brew samples were found to be comparable, ranging from 4.85 to 5.13. The hot brew coffees were found to have higher concentrations of total titratable acids, as well as higher antioxidant activity, than that of their cold brew counterparts. It was also noted that both the concentration of total titratable acids and antioxidant activity correlated poorly with total CQA concentration in hot brew coffee. This work suggests that the hot brew method tends to extract more non-deprotonated acids than the cold brew method. These acids may be responsible for the higher antioxidant activities observed in the hot brew coffee samples.
NF-κB p65 directs sex-specific neuroprotection in human neurons
Authors: Ruiz-Perera Lucia M. , Schneider Lennart , Windmöller Beatrice A. , Müller Janine , Greiner Johannes F. W. , Kaltschmidt Christian , Kaltschmidt Barbara
Published: October 2018

Protection of neurons against oxidative stress is crucial during neuronal development, maintenance and for treating neurodegenerative diseases. However, little is known about the molecular mechanisms underlying sex-specific maturation and survival of neurons. In the present study, we demonstrate NF-κB-p65 mediated neuroprotection in human glutamatergic neurons differentiated from inferior turbinate stem cells (ITSCs) in a sex-dependent manner. We successfully differentiated ITSCs into MAP-2+/NF200+/Synaptophysin+/vGlut2+-glutamatergic neurons in vitro and ex vivo and validated their functionality. TNF-α-dependent NF-κB-p65 activation was accompanied by significant neuroprotection against oxidative stress-induced neuronal death, which was surprisingly higher in neurons from female donors. Accordingly, sex-specific neuroprotection of female neurons was followed by an increased expression of special NF-κB target genes SOD2 and IGF2. Among these, SOD2 is a well known gene protecting cells against oxidative stress resulting in longevity. In addition, IGF2 is known to promote synapse formation and spine maturation, and it has antioxidant and neuroprotective effects against oxidative damage. In conclusion, we show that NF-κB-p65 is a key player in neuroprotection of human neurons, however the protective gene expression program beneath it differs between sexes. Our findings are in accordance with the increasing evidences pointing towards sex-specific differences in risk and severity of neurodegenerative diseases.
Genome sequence of the cauliflower mushroom Sparassis crispa (Hanabiratake) and its association with beneficial usage
Authors: Kiyama Ryoiti , Furutani Yoshiyuki , Kawaguchi Kayoko , Nakanishi Toshio
Published: October 2018

Sparassis crispa (Hanabiratake) is a widely used medicinal mushroom in traditional Chinese medicine because it contains materials with pharmacological activity. Here, we report its 39.0-Mb genome, encoding 13,157 predicted genes, obtained using next-generation sequencing along with RNA-seq mapping data. A phylogenetic analysis by comparison with 25 other fungal genomes revealed that S. crispa diverged from Postia placenta, a brown-rot fungus, 94 million years ago. Several features specific to the genome were found, including the A-mating type locus with the predicted genes for HD1 and HD2 heterodomain transcription factors, the mitochondrial intermediate peptidase (MIP), and the B-mating type locus with seven potential pheromone receptor genes and three potential pheromone precursor genes. To evaluate the benefits of the extract and chemicals from S. crispa, we adopted two approaches: (1) characterization of carbohydrate-active enzyme (CAZyme) genes and β-glucan synthase genes and the clusters of genes for the synthesis of second metabolites, such as terpenes, indoles and polyketides, and (2) identification of estrogenic activity in its mycelial extract. Two potential β-glucan synthase genes, ScrFKS1 and ScrFKS2, corresponding to types I and II, respectively, characteristic of Agaricomycetes mushrooms, were newly identified by the search for regions homologous to the reported features of β-glucan synthase genes; both contained the characteristic transmembrane regions and the regions homologous to the catalytic domain of the yeast β-glucan synthase gene FKS1. Rapid estrogenic cell-signaling and DNA microarray-based transcriptome analyses revealed the presence of a new category of chemicals with estrogenic activity, silent estrogens, in the extract. The elucidation of the S. crispa genome and its genes will expand the potential of this organism for medicinal and pharmacological purposes.
Evidence of natural Zika virus infection in neotropical non-human primates in Brazil
Authors: Terzian Ana Carolina B. , Zini Nathalia , Sacchetto Lívia , Rocha Rebeca Froes , Parra Maisa Carla Pereira , Del Sarto Juliana Lemos , Dias Ana Carolina Fialho , Coutinho Felipe , Rayra Jéssica , da Silva Rafael Alves , Costa Vivian Vasconcelos , Fernandes Natália Coelho Couto De Azevedo , Réssio Rodrigo , Díaz-Delgado Josué , Guerra Juliana , Cunha Mariana S. , Catão-Dias José Luiz , Bittar Cintia , Reis Andréia Francesli Negri , Santos Izalco Nuremberg Penha dos , Ferreira Andréia Cristina Marascalchi , Cruz Lilian Elisa Arão Antônio , Rahal Paula , Ullmann Leila , Malossi Camila , Araújo Jr João Pessoa de , Widen Steven , de Rezende Izabela Maurício , Mello Érica , Pacca Carolina Colombelli , Kroon Erna Geessien , Trindade Giliane , Drumond Betânia , Chiaravalloti-Neto Francisco , Vasilakis Nikos , Teixeira Mauro M. , Nogueira Maurício Lacerda
Published: October 2018

In Africa, Old World Primates are involved in the maintenance of sylvatic circulation of ZIKV. However, in Brazil, the hosts for the sylvatic cycle remain unknown. We hypothesized that free-living NHPs might play a role in urban/periurban ZIKV dynamics, thus we undertook an NHP ZIKV investigation in two cities in Brazil. We identified ZIKV-positive NHPs and sequences obtained were phylogenetically related to the American lineage of ZIKV. Additionally, we inoculated fourC.penicillatawith ZIKV and our results demonstrated that marmosets had a sustained viremia. The natural and experimental infection of NHPs with ZIKV, support the hypothesis that NHPs may be a vertebrate host in the maintainance of ZIKV transmission/circulation in urban tropical settings. Further studies are needed to understand the role they may play in maintaining the urban cycle of the ZIKV and how they may be a conduit in establishing an enzootic transmission cycle in tropical Latin America.
PVA-PDMS-Stearic acid composite nanofibrous mats with improved mechanical behavior for selective filtering applications
Authors: Perween Shama , Khan Ziyauddin , Singh Somendra , Ranjan Amit
Published: October 2018

In this work, we report a facile way to fabricate composite nanofibrous mats of polyvinyl alcohol (PVA), polydimethylsiloxane (PDMS), and stearic acid (SA) by employing the electrospinning-technique, with PDMS fraction ranging from 40w% to nearly 80w%. The results show that for a predetermined fraction of PVA and SA, incorporation of an optimal amount of PDMS is necessary for which the mats exhibit the best mechanical behavior. Beyond this optimal PDMS fraction, the mechanical properties of the composite mats deteriorate. This result has been attributed to the ability of the SA molecules to mediate binding between the PVA and PDMS long-chain molecules via van-der-Waals bonding. The morphological, structural, mechanical, and thermal characterizations respectively using SEM, XRD, DMA/tensile test, and DSC lend support to this explanation. By this method, it is possible to control the hydrophilicity/oleophilicity of the mats, and the mats show an excellent selective permeability to oil as compared to water and successfully filter water from a water-in-oil emulsion. Incorporation of SA not only serves to aid in electrospinning of a PDMS-rich nanofibrous mat with good mechanical strength and control over hydrophilicity/oleophilicity, but also has a potential use in fabricating sheets impregnated with phase change materials for thermal energy storage.
Roughness of surface decorated with randomly distributed pillars
Authors: Weroński Paweł
Published: October 2018

We have presented a quantitative analysis of roughness of planar surfaces decorated with randomly distributed, cylindrical pillars, disks, or cavities. We have described the roughness in terms of the surface power spectral density (PSD). First, we have derived a general equation for the PSD of such surfaces. Then, we have found the PSD for the special case of statistically isotropic, circular areas. We have demonstrated that the PSD provides quantitative information on the radius of the circular area, dimensions of the pillar, and surface coverage. We have also discussed the numerical method of extracting the parameters from experimental PSD data obtained from discrete Fourier transform of surface scanning measurements.
Legume plants may facilitate Zanthoxylum bungeanum tolerance to extreme rainfall
Authors: Li Zilong , Pan Kaiwen , Tariq Akash , Sun Feng , Wang Sizhong , Zhang Lin , Sun Xiaoming , Wu Xiaogang , Song Dagang
Published: October 2018

A complete randomized design was implemented with two watering regimes (extreme rainfall and control) and three different plant combinations (Zanthoxylum bungeanum, Z. bungeanum + Capsicum annum, Z. bungeanum + Glycine max) in order to assess the morphological and physio-biochemical responses of focal and neighbor plants. The results indicated that, extreme rainfall had significantly negative impacts on Z. bungeanum in three intercropping systems. However, intercropping with G. max improved the transpiration rate (Tr) and stomatal conductance (Gs), raised leaf relative water content (LRWC), increased chlorophyll a (Chl a) and carotenoid (Car) content, and enhanced the superoxide dismutase activity (SOD) of Z. bungeanum. After recovery, the Z. bungeanum + G. max mixed culture significantly increased soil NO3−-N, improved the intercellular carbon dioxide concentration (Ci) and Tr, upregulated soluble sugar and proline, and enhanced hydrogen peroxidase activity (CAT). Moreover, the higher root biomass of G. max provided much more nitrogen for Z. bungeanum via the return of organic matter. However, intercropping with C. annum significantly increased active oxygen (ROS). Compared with neighboring species, in intercropping systems, G. max could have improved the tolerance of the focal species Z. bungeanum in response to extreme rainfall and its recovery after extreme rainfall.
Dynamic evolution of inverted repeats in Euglenophyta plastid genomes
Authors: Karnkowska Anna , Bennett Matthew S. , Triemer Richard E.
Published: October 2018

Photosynthetic euglenids (Euglenophyta) are a monophyletic group of unicellular eukaryotes characterized by the presence of plastids, which arose as the result of the secondary endosymbiosis. Many Euglenophyta plastid (pt) genomes have been characterized recently, but they represented mainly one family – Euglenaceae. Here, we report a comparative analysis of plastid genomes from eight representatives of the family Phacaceae. Newly sequenced plastid genomes share a number of features including synteny and gene content, except for genes mat2 and mat5 encoding maturases. The observed diversity of intron number and presence/absence of maturases corroborated previously suggested correlation between the number of maturases in the pt genome and intron proliferation. Surprisingly, pt genomes of taxa belonging to Discoplastis and Lepocinclis encode two inverted repeat (IR) regions containing the rDNA operon, which are absent from the Euglenaceae. By mapping the presence/absence of IR region on the obtained phylogenomic tree, we reconstructed the most probable events in the evolution of IRs in the Euglenophyta. Our study highlights the dynamic nature of the Euglenophyta plastid genome, in particular with regards to the IR regions that underwent losses repeatedly.
The interaction between the Nipah virus nucleocapsid protein and phosphoprotein regulates virus replication
Authors: Ranadheera Charlene , Proulx Roxanne , Chaiyakul Mark , Jones Shane , Grolla Allen , Leung Anders , Rutherford John , Kobasa Darwyn , Carpenter Michael , Czub Markus
Published: October 2018

Continued outbreaks of Henipaviruses in South Asia and Australia cause severe and lethal disease in both humans and animals. Together, with evidence of human to human transmission for Nipah virus and the lack of preventative or therapeutic measures, its threat to cause a widespread outbreak and its potential for weaponization has increased. In this study we demonstrate how overexpression of the Nipah virus nucleocapsid protein regulates viral polymerase activity and viral RNA production. By overexpressing the Nipah virus nucleocapsid protein in trans viral transcription was inhibited; however, an increase in viral genome synthesis was observed. Together, the bias of polymerase activity towards genome production led to the severe inhibition of viral progeny. We identified two domains within the nucleocapsid protein, which were each independently capable of binding the viral phosphoprotein. Evident by our data, we propose that the nucleocapsid protein’s ability to interact with the phosphoprotein of the polymerase complex causes a change in polymerase activity and subsequent deficiency in viral replication. This study not only provides insights into the dynamics of Henipavirus RNA synthesis and replication, but also provides insight into potential targets for antiviral drug development.
CRISPRminer is a knowledge base for exploring CRISPR-Cas systems in microbe and phage interactions
Authors: Zhang Fan , Zhao Shijia , Ren Chunyan , Zhu Yuwei , Zhou Haibin , Lai Yongkui , Zhou Fengxia , Jia Yuqiang , Zheng Kangjie , Huang Zhiwei
Published: October 2018

CRISPR-Cas systems not only play key roles in prokaryotic acquired immunity, but can also be adapted as powerful genome editing tools. Understanding the native role of CRISPR-Cas systems in providing adaptive immunity can lead to new CRISPR-based technologies. Here, we develop CRISPRminer, a knowledge base and web server to comprehensively collect and investigate the knowledge of CRISPR-Cas systems and generate instructive annotations, including CRISPR arrays and Cas protein annotation, CRISPR-Cas system classification, self-targeting events detection, microbe–phage interaction inference, and anti-CRISPR annotation. CRISPRminer is user-friendly and freely available at http://www.microbiome-bigdata.com/CRISPRminer.
New insights of Raman spectroscopy for oral clinical applications
Authors: de Carvalho Luis Felipe das Chagas e Silva , Saito Nogueira Marcelo
Published: October 2018

Oral injuries are currently diagnosed by histopathological analysis of biopsy, which is an invasive procedure and does not give immediate results.
Diastereoselective synthesis of isochromans via the Cu(ii)-catalysed intramolecular Michael-type trapping of oxonium ylides
Authors: Alavala Gopi Krishna Reddy , Sajjad Farrukh , Shi Taoda , Kang Zhenghui , Ma Mingliang , Xing Dong , Hu Wenhao
Published: October 2018

A highly diastereoselective approach for the rapid construction of an isochroman skeleton was achieved by the copper(ii)-catalyzed transformation of alcohol-tethered enones and diazo compounds.
Construction of highly sterically hindered 1,1-disilylated terminal alkenes
Authors: Zhang Xueyan , Ji Xin , Xie Xingze , Ding Shengtao
Published: October 2018

One direct and efficient procedure for the synthesis of 1,1-disilylated terminal alkenes is demonstrated.
Influence of charge transfer on the isomerisation of stilbene derivatives for application in cancer therapy
Authors: Holzmann Nicole , Bernasconi Leonardo , Bisby Roger H. , Parker Anthony W.
Published: October 2018

The photoisomerisation of non-toxictrans-combretastatin CA4 to its cytotoxiccisisomer demonstrates the high potential of this and similar compounds for localised cancer therapy.
Electron transport behavior of quinoidal heteroacene-based junctions: effective electron-transport pathways and quantum interference
Authors: Cheng Na , Chen Feng , Durkan Colm , Wang Nan , He Yuanyuan , Zhao Jianwei
Published: October 2018

Due to the additional p-electrons of the S/O atom, the electron transport behavior of heteroacenes is regulated through quantum interference, showing a significant diversity of the current–voltage curves.
Spectroscopic characterization of a highly selective NiCu3/C hydrodeoxygenation catalyst
Authors: Goulas Konstantinos A. , Lee Jennifer D. , Zheng Weiqing , Lym Jonathan , Yao Siyu , Oh Deborah S. , Wang Cong , Gorte Raymond J. , Chen Jingguang G. , Murray Christopher B. , Vlachos Dionisios G.
Published: October 2018

Formation of a NiO layer atop a NiO–Cu2O bulk under reaction conditions is established via operando XAS.
Design, synthesis and biological evaluation of β-peptoid-capped HDAC inhibitors with anti-neuroblastoma and anti-glioblastoma activity
Authors: Reßing Nina , Marquardt Viktoria , Gertzen Christoph G. W. , Schöler Andrea , Schramm Alexander , Kurz Thomas , Gohlke Holger , Aigner Achim , Remke Marc , Hansen Finn K.
Published: October 2018

Novel β-peptoid-capped HDAC inhibitors with anti-neuroblastoma and anti-glioblastoma activity were synthesized.
Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique
Authors: Tan Xiao , Parmar Harshida , Chaudhary Varun , Zhong Yaoying , Ramanujan Raju V.
Published: October 2018

Nd–Fe–B based magnets, exhibiting the high energy product, synthesized by cost-effective one pot microwave approach.
Switchable synchronisation of pirouetting motions in a redox-active [3]rotaxane
Authors: Schröder Hendrik V. , Mekic Amel , Hupatz Henrik , Sobottka Sebastian , Witte Felix , Urner Leonhard H. , Gaedke Marius , Pagel Kevin , Sarkar Biprajit , Paulus Beate , Schalley Christoph A.
Published: October 2018

A redox-active [3]rotaxane is reported, in which wheel pirouetting motions can be synchronised by electrochemical switching.
Development of high damping acrylic rubber/sliding graft copolymer composites
Authors: Wang Junjun , Wang Wencai , Geng Xiaoyan , Nishi Toshio , Zhao Xiuying , Zhang Liqun
Published: October 2018

Novel supramolecular material-sliding graft copolymer (SGC)/acrylic rubber (ACM) composites with significantly improved damping performance were successfully prepared.
A step forward in the development ofin situproduct recovery by reactive separation of protocatechuic acid
Authors: De Biswajit S. , Wasewar Kailas L. , Dhongde Vicky , Mishra Tanya
Published: October 2018

A conceptual design of an ISPR configuration for the biosynthesis, separation, and recovery of PCA by reactive extraction with TBP in natural non-toxic diluents.
Computation and assessment of solar electrolyzer field performance: comparing coupling strategies
Authors: Sriramagiri Gowri M. , Luc Wesley , Jiao Feng , Ayers Kathy , Dobson Kevin D. , Hegedus Steven S.
Published: October 2018

Schematic of a photovoltaic electrolysis system employed with different coupling strategies: direct, DC–DC or DC–AC–DC.
The benefits of macromolecular hydrogen sulfide prodrugs
Authors: Connal Luke A.
Published: October 2018

The potential of H2S can be realised with design of macromolecular prodrugs.
Hexagonal M2C3 (M = As, Sb, and Bi) monolayers: new functional materials with desirable band gaps and ultrahigh carrier mobility
Authors: Liu Peng-Fei , Bo Tao , Liu Zhifeng , Eriksson Olle , Wang Fangwei , Zhao Jijun , Wang Bao-Tian
Published: October 2018

We theoretically identify the existence of 2D multifunctional semiconductors M2C3 (M = As, Sb, and Bi).
Alleviating congestion of hybrid urban grid by VSC‐control and AC‐line switching
Authors: Xiong Qian , Li Yong , Peng Hai , Zhang Xi , Liu Youbo , Liu Xianglong
Published: October 2018

As electricity load in large cities overgrows these years, mainly due to the increasing penetration of electric vehicles, the urban transmission networks are subject to the high risk of congestion because of insufficient planning. Reconfigure the high‐voltage distribution network (HVDN) is an efficient way to mitigate the urban congestion. However, the discrete load transfer amount is not precise that might cause load curtailment, and the computation burden is also heavy when the system scale is enormous. In recent years, the emergence of voltage source converter (VSC) as the core components of DC transmission technique provides a new control measurement featuring fast and flexible. Nevertheless, its adjusting capacity is limited and subject to the system topological structure. Thus this paper proposed a coordinative control model that combines the load transfer capability of the HVDN and flexible and precise control of VSC to alleviate the urban transmission congestion. Numerical results showed that the congestion lines could be efficiently relieved thus defer further investment in the transmission network.
End‐to‐end learning for high‐precision lane keeping via multi‐state model
Authors: Yuan Wei , Yang Ming , Li Hao , Wang Chunxiang , Wang Bing
Published: October 2018

High‐precision lane keeping is essential for the future autonomous driving. However, due to the imbalanced and inaccurate datasets collected by human drivers, current end‐to‐end driving models have poor lane keeping the effect. To improve the precision of lane keeping, this study presents a novel multi‐state model‐based end‐to‐end lane keeping method. First, three driving states will be defined: going straight, turning right and turning left. Second, the finite‐state machine (FSM) table as well as three kinds of training datasets will be generated based on the three driving states. Instead of collecting the dataset by human drivers, the accurate dataset will be collected by the high‐performance path following controller. Third, three sets of parameters based on 3DCNN‐LSTM model will be trained for going straight, turning left and turning right, which will be combined with FSM table to form a multi‐state model. This study evaluates the multi‐state model by testing it on five tracks and recording the lane keeping error. The result shows the multi‐state model‐based end‐to‐end method performs the higher precision of lane keeping than the traditional single end‐to‐end model.
Fast object detection based on binary deep convolution neural networks
Authors: Sun Siyang , Yin Yingjie , Wang Xingang , Xu De , Wu Wenqi , Gu Qingyi
Published: October 2018

In this study, a fast object detection algorithm based on binary deep convolution neural networks (CNNs) is proposed. Convolution kernels of different sizes are used to predict classes and bounding boxes of multi‐scale objects directly in the last feature map of a deep CNN. In this way, rapid object detection with acceptable precision loss is achieved. In addition, binary quantisation for weight values and input data of each layer is used to squeeze the networks for faster object detection. Compared to full‐precision convolution, the proposed binary deep CNNs for object detection results in 62 times faster convolutional operations and 32 times memory saving in theory, what's more, the proposed method is easy to be implemented in embedded computing systems because of the binary operation for convolution and low memory requirement. Experimental results on Pascal VOC2007 validate the effectiveness of the authors’ proposed method.
Long-term optical monitoring of TeV emitting blazars
Authors: Nilsson K. , Lindfors E. , Takalo L. O. , Reinthal R. , Berdyugin A. , Sillanpää A. , Ciprini S. , Halkola A. , Heinämäki P. , Hovatta T. , Kadenius V. , Nurmi P. , Ostorero L. , Pasanen M. , Rekola R. , Saarinen J. , Sainio J. , Tuominen T. , Villforth C. , Vornanen T. , Zaprudin B.
Published: October 2018

We present ten years of R-band monitoring data of 31 northern blazars which were either detected at very high-energy (VHE) gamma rays or listed as potential VHE gamma-ray emitters. The data comprise 11 820 photometric data points in the R-band obtained in 2002–2012. We analyzed the light curves by determining their power spectral density (PSD) slopes assuming a power-law dependence with a single slope β and a Gaussian probability density function (PDF). We used the multiple fragments variance function (MFVF) combined with a forward-casting approach and likelihood analysis to determine the slopes and perform extensive simulations to estimate the uncertainties of the derived slopes. We also looked for periodic variations via Fourier analysis and quantified the false alarm probability through a large number of simulations. Comparing the obtained PSD slopes to values in the literature, we find the slopes in the radio band to be steeper than those in the optical and gamma rays. Our periodicity search yielded one target, Mrk 421, with a significant (p <  5%) period. Finding one significant period among 31 targets is consistent with the expected false alarm rate, but the period found in Mrk 421 is very strong and deserves further consideration.
A Novel Adaptive Control Method Based on Continuous Characteristic Models
Authors: Zhou Jun , Ge Zhenzhen , Guo Jianguo
Published: October 2018

For a class of nonlinear systems, a novel adaptive control scheme is proposed in this paper. Firstly, the continuous characteristic model is constructed, which is equivalent to its original system in output for the same input at any time. Thus, the original system can be replaced with its characteristic model for designing controllers. As the original nonlinear system has unknown parameters and unmodeled dynamics, the characteristic parameters are also unknown and fast time-varying. A novel adaptive control method is proposed by combining the continuous characteristic model with the adaptive dynamic surface control technique. The method is independent on the original system model and only utilizes the information about system output for controlling. On account of the fact, the system inner states, unknown parameters and unmodeled dynamics are not needed to be observed. Finally, the stability of the closed loop system is proved by utilizing Lyapunov theory and simulation results have demonstrated the effectiveness of the proposed method.
Low Frequency Sound Field Reproduction within a Cylindrical Cavity Using Higher Order Ambisonics
Authors: Wang Yan , Chen Kean , Xu Jian
Published: October 2018

Sound field reproduction of the aircraft and submarine within a cabin mock-up using a loudspeaker array is of great importance to the active noise control technology.The conventional method is to calculate the driving functions of the secondary sources by solving an acoustic inverse problem in a least square sense, which requires a large number of microphones and only the sound field near the microphone array can be reproduced accurately.In order to overcome these drawbacks, higher order ambisonics (HOA) method which is widely used in spatial sound field synthesis for a large room is introduced to reproduce a low frequency sound field within a cylindrical cavity.Due to the different sound propagation characteristics within the cavity compared with a free field and a diffuse field, the Green function spectrum in spherical harmonics domain which is modeled as a superposition of the acoustic modes and the reproduction formulas are deduced.Reproduction characteristics are investigated by numerical simulations.Results show that for a small, the Green function spectrum in spherical harmonics domain is mainly concentrated on low orders and contributed by the low order acoustic modes, with the increase of, high order components of the Green function arise and the contributions of high order acoustic modes increase.In the reproduction process, the high order components of the pressure spectrum over the sphere in harmonics domain will be greatly amplified by the reproduction filter.Finally, HOA method is compared with the acoustic inversion method in terms of the microphone array system, the impact factors on the reproductions and the reproduction accuracy, and validated through experiments.Results show that HOA can better reproduce the entire sound field within the cylindrical cavity and the reproduction accuracy is improved.
Active Sonar Target Tracking Based on the GM-CPHD Filter Algorithm
Authors: Chen Xiao , Li Yaan , Li Yuxing , Yu Jing
Published: October 2018

The estimation of underwater multi-target state has always been the difficult problem of active sonar target tracking.In order to get the variable number of target and their state, the random finite set theory is applied to multi-target tracking system.This theory not only effectively avoids the problem of multi-target tracking data association, and also realizes the estimation of time-varying number of targets and their states.Due to Probability Hypothesis Density(PHD) recursion propagates cardnality distribution with only a single parameter, a new generalization of the PHD recursion called Cardinalized Probability Hypothesis Density(CPHD) recursion, which jointly propagates the intensity function and the cardnality distribution, while have a big computation than PHD.Also there did not have closed-form solution for PHD recursion and CPHD recursion, so for linear Gaussian multi-target tracking system, the Gaussian Mixture Probability Hypothesis Density and Gaussian Mixture Cardinalized Probability Hypothesis Density(GM-CPHD) filter algorithm is put forward.GM-CPHD is more accurate than GM-PHD in estimation of the time-varying number of targets.In this paper, we use the ellipse gate tracking strategy to reduce computation in GM-CPHD filtering algorithm.At the same time, according to the characteristics of underwater target tracking, using active sonar equation, we get the relationship between detection probability, distance and false alarm, when fixed false alarm, analytic formula of the relationship between adaptive detection probability and distance is obtained, we puts forward the adaptive detection probability GM-CPHD filtering algorithm.Simulation shows that the combination of ellipse tracking gate strategy and adaptive detection probability GM-CPHD filtering algorithm can realize the estimation of the time-varying number of targets and their state more accuracy in dense clutter environment.
Multi-Step Structural Optimization Design of Multi-Bubble Pressure Cabin in the Autonomous Underwater Vehicle with Blended-Wing-Body
Authors: He Yanru , Song Baowei , Cao Yonghui
Published: October 2018

In this paper, multi-bubble pressure cabin is proposed for the flat fuselage of blended-wing-body(BWB) autonomous underwater vehicle(AUV). It has strong compressive capacity and makes full use of the fuselage space. Radial basis function surrogate model and Kriging surrogate model are used to construct mixture surrogate model for higher accuracy. Two infill sampling methods are adopted:the candidate point sampling and the local optimal sampling. Multi-step optimization of multi-bubble pressure cabin is carried out including shape optimization and structure optimization. To optimize shape, the maximum displacement is selected as the objective function and the shape constraint is chosen as the constraint condition. The minimum structural quality is selected as the objective function, the maximum equivalent stress and bulking factor are chosen as the constraint condition to optimize structure. Finite element method(FEM) analysis is carried out to study the strength and stability performance of multi-bubble pressure cabin using the commercial computational structural mechanics code ANSYS.
Study on Auditory Perception Variability Caused by Distinct Structural Parameters of the Enclosure Space
Authors: Li Rong , Zeng Xiangyang , Wang Haitao , Li Na
Published: October 2018

The enclosure space is widespread in real life. However, from the angle on spatial hearing to study the variation of auditory perception caused by the changed structural parameters (such as volume, shape, etc) are very rare, particular in systematically research. In this paper, based on auditory scene simulation, the binaural auralization and sound field measurement techniques are used to obtain plenty of binaural signals in diverse enclosure spaces with different structural parameters. Subsequently, with the aid of the acoustic evaluation, the quantitative evaluation of spatial auditory perception change and its degree was carried out on the binaural signal. Major findings are summarized as follows:①The change of the volume, shape, absorption coefficient of indoor walls of enclosure space can induce the variation of auditory perception of sound field. According to the degree of change (from obvious to not), the absorption coefficient of indoor walls, the shape, the volume is sorted. ②changing the receiving location could affect the variation on auditory perception caused by the volume and shape of an enclosure space.
Sensorless Control of Permanent Magnet Synchronous Motor Based on the Improved Sliding Mode Observer
Authors: Hua Zhiguang , Dou Manfeng , Zhao Dongdong , Yan Liming , Ji Junpeng , Yang Jianwei
Published: October 2018

Sliding mode observer (SMO) which has a strong robustness is used in the sensorless control system of permanent magnet synchronous motor (PMSM). The method is usually used to estimate the rotor position although it has the chattering problem. According to the causes of the chattering in traditional SMO, the method of improved sliding mode observer (ISMO) is proposed in this paper. Sign function is replaced by the saturation function to suppress the chattering problem, and the speed of PMSM is estimate when combined with field oriented control (FOC) method. A hardware platform of 2.7 kW, 10 000 r/min PMSM is built to verify the control effectiveness of ISMO. Simulation analysis and experimental result show that ISMO can estimate the rotor speed accuracy and reduce the chatting at the same time.
Investigation of Slotted Tip Parameters on the Aerodynamic Characteristic of Helicopter Rotor
Authors: Chen Rongqian , Wang Xu , Chen Qiyou , Zhu Chengxiang , You Yancheng
Published: October 2018

Numerical simulations are conducted to investigate the effect of helicopter rotor tip vortex alleviation using a slotted tip, and effects of parameters involving location, number, aperture of the slot on tip vortex structure and aerodynamic performance are analyzed in detail. The flow field of hovering helicopter rotor is simulated by solving Navier-Stokes equations in the rotating coordinate system. Finite volume method combined with overset unstructured grids algorithm are adopted. The calculation of inviscid fluxes uses second-order central scheme with artificial dissipation, and turbulence model utilizes Spalart-Allmaras model. Simulation results show that the location of the slot has little effect on tip vortex alleviation. The larger the number and aperture of the slot, the better the effect of slotted tips weakening tip vortex. Lift coefficient of helicopter rotor with a slotted tip increases slightly compared with that without slots, while power coefficient increases drastically.
What is a moth doing under water? Ecology of aquatic and semi-aquatic Lepidoptera
Authors: Pabis Krzysztof
Published: October 2018

This paper reviews the current knowledge on the ecology of aquatic and semi-aquatic moths, and discusses possible pre-adaptations of the moths to the aquatic environment. It also highlights major gaps in our understanding of this group of aquatic insects. Aquatic and semi-aquatic moths represent only a tiny fraction of the total lepidopteran diversity. Only about 0.5% of 165 000 known lepidopterans are aquatic; mostly in the preimaginal stages. Truly aquatic species can be found only among the Crambidae, Cosmopterigidae and Erebidae, while semi-aquatic forms associated with amphibious or marsh plants are known in thirteen other families. These lepidopterans have developed various strategies and adaptations that have allowed them to stay under water or in close proximity to water. Problems of respiratory adaptations, locomotor abilities, influence of predators and parasitoids, as well as feeding preferences are discussed. Nevertheless, the poor knowledge on their biology, life cycles, genomics and phylogenetic relationships preclude the generation of fully comprehensive evolutionary scenarios.
Les mesures atomiques de haute précision. Un outil privilégié pour tester l’électrodynamique quantique
Authors: Cladé Pierre , Julien Lucile
Published: October 2018

À la fin des années 1940, l'étude des niveaux d'énergie de l'atome d'hydrogène et celle de l'anomalie du rapport gyromagnétique de l'électron ont été à l'origine de l'électrodynamique quantique.

Aujourd'hui encore, les mesures réalisées dans les systèmes atomiques simples, telles que celles que nous menons au laboratoire Kastler Brossel, permettent de tester les prédictions de cette théorie à un niveau de précision extrême qui, à ce jour, n'a pas réussi à la mettre en défaut.
SPIRAL2 : une sonde de nouvelle génération pour explorer la matière nucléaire
Authors: Savalle Alain , Jardin Pascal , Ferdinand Robin , Ledoux Xavier , Thomas Jean-Charles , Savajols Hervé , Bertrand Patrick
Published: October 2018

SPIRAL2 est un accélérateur d'ions de nouvelle génération, qui va agrandir et renforcer le GANIL (Grand accélérateur national d'ions lourds, installé à Caen et géré par le CEA et le CNRS).

Il fournira des faisceaux d'ions lourds et légers d'intensité inégalée, qui seront utilisés pour produire de nouveaux éléments superlourds et compléter ainsi le tableau de Mendeleïev, pour créer et étudier des noyaux exotiques qui n'existent que dans le cosmos, ou encore pour étudier les effets de l'irradiation de la matière par les neutrons rapides.
Reconnexion magnétique entre le vent solaire et la magnétosphère terrestre : la mission MMS
Authors: Rezeau Laurence , Belmont Gérard
Published: October 2018

Dans le vent solaire, plasma et champ magnétique se déplacent ensemble à grande échelle. L'interface avec la magnétosphère terrestre est une frontière fine, la magnétopause, où il peut exister des échelles suffisamment petites où les deux mouvements se dissocient. Il en résulte un phénomène nommé « reconnexion magnétique », au cours duquel le plasma est fortement accéléré le long de la frontière.

La mission MMS a des points forts qui en font le meilleur outil pour étudier ce phénomène : une résolution temporelle des mesures inégalée, et des satellites très proches les uns des autres (environ 10 km, de l'ordre du rayon de Larmor des électrons dans les plasmas rencontrés).
Conférences expérimentales à l’Espace Pierre-Gilles de Gennes
Authors: Bico José , Guyon Étienne , Lehoucq Roland
Published: October 2018

Après un rappel historique sur les démonstrations publiques d’expériences scientifiques depuis les cabinets de physique du 18e siècle, cet article présente les leçons expérimentales mises en place à l’ESPCI depuis 2003, qui se sont donné l’objectif de présenter « en direct » la science d’aujourd’hui. Ces conférences, gratuites et ouvertes à tous, qui montrent aussi bien la manipulation d’une chaîne d’ADN que des expériences avec des jeux, sont filmées et mises à disposition sur Canal-U pour les rendre durablement accessibles au public.

À titre d’exemple, deux encadrés décrivent des extraits d’une leçon donnée en 2017 par R. Lehoucq, sur l’utilisation de jouets (le yo-yo et le ressort slinky) pour parler de physique.
Eine Inventur in der Rheumatologie – Neues zur Versorgungsforschung
Authors: Feist Eugen
Published: October 2018

Liebe Kollegen,

eine Inventur ist in der Regel mit einem erheblichen Aufwand verbunden, der nicht immer nur Enthusiasmus auslöst. Dennoch ist die regelmäßige Bestandsaufnahme durchaus wichtig, um den erreichten Stand zu dokumentieren, aber auch weiterhin bestehende oder neue Probleme aufzudecken. In dieser Ausgabe der Aktuellen Rheumatologie widmen sich verschiedene Arbeitsgruppen der Versorgungssituation für Kinder und Erwachsene mit rheumatischen Erkrankungen in Deutschland und Österreich. Als Quellen dienen dabei Daten sowohl aus der Kerndokumentation und Registern als auch Informationen aus Fachgesellschaften und veröffentlichten Studien, um einen breit gefächerten und somit realistischen Blick zu ermöglichen.
Ergebnisse spektraler optischer Kohärenztomografie bei den mit Chloroquin behandelten Patienten mit systemischem Lupus erythematodes
Authors: Kosic Knez Nina , Šiško Katarina , Holc Iztok , Pahor Dusica , Pahor Artur , Gracner Tomaz
Published: October 2018

Ziel Das Ziel unserer Studie war es, mögliche Netzhautveränderungen bei den mit Chloroquinphosphat behandelten SLE-Patienten (SLE: systemischer Lupus erythematodes) festzustellen und zwar in Bezug auf die Behandlungsdauer.

Methoden In die Studie wurden 41 SLE-Patienten (82 Augen) eingeschlossen, die mit Chloroquinphosphat oder Hydroxychloroquinphosphat behandelt werden und bei denen noch keine Netzhautpathologie diagnostiziert worden ist. Studienteilnehmende wurden entsprechend der Behandlungsdauer in 2 Gruppen eingeteilt. Die 1. Gruppe umfasste 18 Patienten (36 Augen), die einer bis zu 5-jährigen Behandlung unterzogen wurden, und die 2. Gruppe bestand aus 23 Patienten (46 Augen), die von 5 – 20 Jahren behandelt wurden. Es wurde eine gründliche Augenuntersuchung durchgeführt, einschließlich bestkorrigierter Sehschärfe, Farbsehen, Gesichtsfelduntersuchung, Fundusuntersuchung bei dilatierten Pupillen, Autofluoreszenzuntersuchung, Fundusfotografie und Spectral-Domain optische Kohärenztomografie (SD-OCT).

Ergebnisse Die durchschnittliche Behandlungsdauer der 1. Gruppe betrug 2,79 ± 1,37 Jahre, während die 2. Gruppe im Durchschnitt 8,67 ± 2,26 Jahre behandelt wurde. Der Unterschied in der zentralen Netzhautdicke zwischen den beiden Gruppen war statistisch insignifikant (p > 0,05). Der Vergleich der parafovealen Dicke zwischen den beiden Gruppen war in allen Regionen statistisch insignifikant (p > 0,05). Gesichtsfelduntersuchung, Autofluoreszenzuntersuchung und Fundusfotografie waren ohne nennenswerte Pathologie.

Schlussfolgerung Unsere Ergebnisse zeigen keine statistisch signifikanten Veränderungen in der Netzhautstruktur zwischen den beiden Gruppen und in Bezug auf die Behandlungsdauer. Infolgedessen kann man schließen, dass jährliche Nachuntersuchungen dieser Patienten sicher genug sind, um mögliche präklinische Makulopathie festzustellen.
Die Devaskularisationsoperation zur Behandlung von Fundus- und Ösophagusvarizen bei portaler Hypertension – eine retrospektive Analyse von 55 Fällen
Authors: Overhaus Marcus , Garcia Park Lydia , Fimmers Rolf , Glowka Tim , van Beekum Cornelius , Manekeller Steffen , Kalff Jörg , Schaefer Nico , Vilz Tim
Published: October 2018

Hintergrund Die gefährlichste Komplikation einer portalen Hypertension ist die Ausbildung von Ösophagusvarizen, das Risiko für eine Blutung beträgt bis zu 80%. Zur Drucksenkung im portalsystemischen Kreislauf und als Sekundärprophylaxe hat sich die Anlage eines transjugulären, portosystemischen Stent-Shunts (TIPSS) bewährt, bei Pfortaderthrombosen ist die operative Anlage eines portosystemischen Shunts möglich. Besteht jedoch eine Thrombose der mesenterikoportalen Achse oder droht eine hepatische Enzephalopathie, ist die interventionelle oder operative Anlage eines portosystemischen Shunts kontraindiziert. Als Ultima Ratio zur Vermeidung von Rezidivblutungen oder notfallmäßig bei aktiver Blutung kann in diesen Fällen eine Sperroperation indiziert sein. Ziel dieser Studie war es, die perioperative Komplikationsrate, die Morbidität und Mortalität, die Inzidenz einer postoperativen Rezidivblutung sowie das Überleben von Patienten nach erfolgter Sperroperation zu untersuchen.

Patienten und Methoden Es wurden 55 Patienten mit überstandener oder akuter Varizenblutung ohne Möglichkeit der Anlage eines interventionellen oder operativen portosystemischen Shunts hinsichtlich Komplikationsrate, Ausbildung von Rezidivvarizen, erneuter Blutung sowie Überleben retrospektiv untersucht.

Ergebnisse Während die Komplikationsrate bei elektiven Eingriffen 61% betrug, stieg sie bei Notfall-OPs signifikant an (75%, p = 0,002), dies betraf insbesondere Komplikationen Dindo/Clavien Grad III – V (14 vs. 58%, p = 0,002). Durch die Sperr-OP konnte die Ausprägung der Varizen deutlich gesenkt werden, eine Rezidivblutung trat nur bei 16% der Patienten in einer Nachbeobachtungszeit von bis zu 24 Jahren auf. Das mittlere Überleben (mÜL) nach Sperr-OP betrug 169 ± 23 Monate. Nach elektiver OP war das mÜL194 ± 25 Monate, nach notfallmäßiger Sperr-OP nur 49 ± 16 Monate. Interessanterweise zeigte kein Patient eine hepatische Enzephalopathie im Verlauf.

Schlussfolgerung Die Sperr-OP ist gut geeignet zur Sekundärprophylaxe bei Patienten mit Fundus- sowie Ösophagusvarizen und portaler Hypertension ohne Möglichkeit eines portosystemischen Shunts oder bei drohender hepatischer Enzephalopathie. Wird jedoch die Operation in der Notfallsituation durchgeführt, treten signifikant mehr Majorkomplikationen auf, das Outcome ist deutlich schlechter. Daher sollte insbesondere bei fehlender Möglichkeit einer Drucksenkung im portalvenösen System und unter Endoskopie bei progredienten Varizen frühzeitig eine elektive Sperroperation in Erwägung gezogen werden.
Offener Ersatz der gesamten thorakalen Aorta über einen „clamshell“-Zugang bei aortoösophagealer Fistel – eine multidisziplinäre Herausforderung
Authors: Gombert Alexander , Grommes Jochen , Kotelis Drosos , Jacobs Michael
Published: October 2018

Einleitung Aortoösophageale Fisteln infolge offener und endovaskulärer Operationen der thorakoabdominellen Aorta sind seltene und lebensbedrohliche Erkrankungen. Im vorliegenden Fall war durch die infektiöse Mitbeteiligung einer einliegenden Ascendens-Bogenprothese sowie einer thorakalen Endoprothese im Bereich der Aorta descendens der vollständige Ersatz der thorakalen Aorta über einen sog. „clamshell“-Zugang notwendig.

Kasuistik Bei einer Aortendissektion Typ A nach Stanford erfolgte bei einer 43-jährigen Patientin 2015 ein suprakoronarer Aortenersatz. 2016 wurde bei aortoösophagealer Fistel mit schweren Hämoptysen notfallmäßig eine thorakale Stentprothese (TEVAR) implantiert. Zur definitiven Versorgung mit Entfernung des infizierten Prothesenmaterials erfolgte ein vollständiger Ersatz der thorakalen Aorta im Rahmen einer queren Thorakotomie als Teil eines multimodalen Therapiekonzeptes. Bereits vorab war eine Ösophagektomie erfolgt; abschließend wurde die Passage mittels eines sekundären antesternalen Magenhochzugs rekonstruiert.

Schlussfolgerung Aortoösophageale Fisteln stellen eine therapeutische Herausforderung dar, die in Referenzzentren durch ein interdisziplinäres Team behandelt werden sollten. Der „clamshell“-Zugang mittels querer Thorakotomie ermöglichte im vorliegenden Fall den Ersatz der gesamten thorakalen Aorta.