bluuebunny/crossref_metadata_2025 huggingface dataset:
A convolutional neural network-based system to prevent patient misidentification in FDG-PET examinations
Authors: Kawauchi Keisuke , Hirata Kenji , Katoh Chietsugu , Ichikawa Seiya , Manabe Osamu , Kobayashi Kentaro , Watanabe Shiro , Furuya Sho , Shiga Tohru
Published: May 2019

Patient misidentification in imaging examinations has become a serious problem in clinical settings. Such misidentification could be prevented if patient characteristics such as sex, age, and body weight could be predicted based on an image of the patient, with an alert issued when a mismatch between the predicted and actual patient characteristic is detected. Here, we tested a simple convolutional neural network (CNN)-based system that predicts patient sex from FDG PET-CT images. This retrospective study included 6,462 consecutive patients who underwent whole-body FDG PET-CT at our institute. The CNN system was used for classifying these patients by sex. Seventy percent of the randomly selected images were used to train and validate the system; the remaining 30% were used for testing. The training process was repeated five times to calculate the system’s accuracy. When images for the testing were given to the learned CNN model, the sex of 99% of the patients was correctly categorized. We then performed an image-masking simulation to investigate the body parts that are significant for patient classification. The image-masking simulation indicated the pelvic region as the most important feature for classification. Finally, we showed that the system was also able to predict age and body weight. Our findings demonstrate that a CNN-based system would be effective to predict the sex of patients, with or without age and body weight prediction, and thereby prevent patient misidentification in clinical settings.
Genetic inhibition of CRMP2 phosphorylation at serine 522 promotes axonal regeneration after optic nerve injury
Authors: Kondo Shunsuke , Takahashi Kazuya , Kinoshita Yuki , Nagai Jun , Wakatsuki Shuji , Araki Toshiyuki , Goshima Yoshio , Ohshima Toshio
Published: May 2019

Axonal degeneration occurs in various neurological diseases and traumatic nerve injury, and axonal regeneration is restricted by inhibitory factors in the central nervous system. Cyclin-dependent kinase 5 and glycogen synthase kinase 3β (GSK3β) are activated by one of those inhibitors, and collapsin response mediator protein 2 (CRMP2) is phosphorylated by both kinases. We previously developed a CRMP2 knock-in (CRMP2 KI) mouse line, in which CRMP2 phosphorylation at Ser 522 is inhibited. Because CRMP2 KI mice showed promotion of axonal regeneration after spinal cord injury, we hypothesized that CRMP2 KI mice would show higher axonal regeneration after optic nerve injury. In this study, we first show that depolymerization of microtubules after optic nerve crush (ONC) injury was suppressed in CRMP2 KI mice. Loss of retinal ganglia cells was also reduced after ONC. We found that protein level of GAP43, a marker of regenerative axons, was higher in the optic nerve from CRMP2KI than that from wild type 4 weeks after of ONC. We further observed increased numbers of axons labeled by tracer in the optic nerve after ONC in CRMP2 KI mice. These results suggest that inhibition of phosphorylation of CRMP2 suppresses axonal degeneration and promotes axonal regeneration after optic nerve injury.
A phospholipase D2 inhibitor, CAY10594, ameliorates acetaminophen-induced acute liver injury by regulating the phosphorylated-GSK-3β/JNK axis
Authors: Lee Sung Kyun , Bae Geon Ho , Kim Ye Seon , Kim Hyung Sik , Lee Mingyu , Ghim Jaewang , Zabel Brian A. , Ryu Sung Ho , Bae Yoe-Sik
Published: May 2019

We examined the role of phospholipase D2 (PLD2) on acetaminophen (APAP)-induced acute liver injury using a PLD2 inhibitor (CAY10594). 500 mg/kg of APAP challenge caused acute liver damage. CAY10594 administration markedly blocked the acute liver injury in a dose-dependent manner, showing almost complete inhibition with 8 mg/kg of CAY10594. During the pathological progress of acute liver injury, GSH levels are decreased, and this is significantly recovered upon the administration of CAY10594 at 6 hours post APAP challenge. GSK-3β (Serine 9)/JNK phosphorylation is mainly involved in APAP-induced liver injury. CAY10594 administration strongly blocked GSK-3β (Serine 9)/JNK phosphorylation in the APAP-induced acute liver injury model. Consistently, sustained JNK activation in the cytosol and mitochondria from hepatocytes were also decreased in CAY10594-treated mice. Many types of immune cells are also implicated in APAP-induced liver injury. However, neutrophil and monocyte populations were not different between vehicle- and CAY10594-administered mice which are challenged with APAP. Therapeutic administration of CAY10594 also significantly attenuated liver damage caused by the APAP challenge, eliciting an enhanced survival rate. Taken together, these results indicate that PLD2 is involved in the intrinsic response pathway of hepatocytes driving the pathogenesis of APAP-induced acute liver injury, and PLD2 may therefore represent an important therapeutic target for patients with drug-induced liver injury.
Transducin activates cGMP phosphodiesterase by trapping inhibitory γ subunit freed reversibly from the catalytic subunit in solution
Authors: Asano Teizo , Kawamura Satoru , Tachibanaki Shuji
Published: May 2019

Activation of cGMP phosphodiesterase (PDE) by activated transducin α subunit (Tα*) is a necessary step to generate a light response in vertebrate photoreceptors. PDE in rods is a heterotetramer composed of two catalytic subunits, PDEα and PDEβ, and two inhibitory PDEγ subunits, each binding to PDEα or PDEβ. Activation of PDE is achieved by relief of the inhibitory constraint of PDEγ on the catalytic subunit. In this activation mechanism, it is widely believed that Tα* binds to PDEγ still bound to the catalytic subunit, and removes or displaces PDEγ from the catalytic subunit. However, recent structural analysis showed that the binding of Tα* to PDEγ still bound to PDEα or PDEβ seems to be difficult because the binding site of PDEγ to PDEα or PDEβ overlaps with the binding site to Tα*. In the present study, we propose a novel activation mechanism of PDE, the trapping mechanism, in which Tα* activates PDE by trapping PDEγ released reversibly and spontaneously from the catalytic subunit. This mechanism well explains PDE activation by Tα* in solution. Our further analysis with this mechanism suggests that more effective PDE activation in disk membranes is highly dependent on the membrane environment.
Visualization of unstained DNA nanostructures with advanced in-focus phase contrast TEM techniques
Authors: Kabiri Yoones , Ravelli Raimond B. G. , Lehnert Tibor , Qi Haoyuan , Katan Allard J. , Roest Natascha , Kaiser Ute , Dekker Cees , Peters Peter J. , Zandbergen Henny
Published: May 2019

Over the last few years, tremendous progress has been made in visualizing biologically important macromolecules using transmission electron microscopy (TEM) and understanding their structure-function relation. Yet, despite the importance of DNA in all forms of life, TEM visualization of individual DNA molecules in its native unlabeled form has remained extremely challenging. Here, we present high-contrast images of unstained single-layer DNA nanostructures that were obtained using advanced in-focus phase contrast TEM techniques. These include sub-Ångstrom low voltage electron microscopy (SALVE), the use of a volta-potential phase plate (VPP), and dark-field (DF) microscopy. We discuss the advantages and drawbacks of these techniques for broad applications in structural biology and materials science.
miR-494 induces EndMT and promotes the development of HCC (Hepatocellular Carcinoma) by targeting SIRT3/TGF-β/SMAD signaling pathway
Authors: Zhang Jinqian , Zhu Yan , Hu Liangshan , Yan Fang , Chen Jinglong
Published: May 2019

EndMT has an important effect on metastasis and progression of tumor. This work will elucidate the effect of miR-494 on EndMT and development of HCC. Therefore, the differential miRNA expression among non-tumorous, para-tumorous and tumorous tissues was analyzed. Moreover, luciferase activities of SIRT3 3′UTR treated with miR-494 were determined. Then human hepatoma cell lines were dealt with mimics or inhibitors of miR-494, migration and proliferation ability were assessed. The expression of SIRT3 and markers of mesenchymal cell were analyzed. The influences of miR-494 on development of HCC through inducing EndMT by targeting SIRT3 and TGF-β/SMAD signaling pathways in hepatoma cell lines were investigated. Xenograft mice were used to explore the potential roles of miR-494 on EndMT and development of HCC in vivo. Our results showed that, compared with non-tumorous tissues, 17 miRNAs were upregulated and 3 miRNAs were down-regulated in tumor tissues. In tumor tissues, the miR-494 expression level was much more than the expression of para-tumorous and non-tumorous tissues. MiR-494 suppressed SIRT3 expression, additionally enhanced expression of mesenchymal cell markers, while exerted effects on cell proliferation and migration of hepatoma cell lines. Moreover, the antagomir of miR-494 could protect against development process in xenogarft murine model. In conclusions, our work demonstrated that miR-494 targeted to SIRT3, and was a crucial mediator of EndMT and development of HCC through regulating SIRT3/TGF-β/SMAD signaling pathway. It suggested that aim at SIRT3/TGF-β/SMAD signaling pathway through suppressing the miR-494 expression level, was a feasible therapy strategy for HCC.
Attenuated NoGo-related beta desynchronisation and synchronisation in Parkinson’s disease revealed by magnetoencephalographic recording
Authors: Wu Hung-Ming , Hsiao Fu-Jung , Chen Rou-Shayn , Shan Din-E , Hsu Wan-Yu , Chiang Ming-Chang , Lin Yung-Yang
Published: May 2019

Parkinson’s disease (PD) is a neurodegenerative disorder characterised by motor abnormalities. Many non-demented patients with PD have cognitive impairment especially in executive functions. Using magnetoencephalographic (MEG) recording combined with event-related desynchronisation/synchronisation (ERD/ERS) analysis, we investigated cortical executive functions during a Go/NoGo task in PD patients and matched healthy subjects. PD patients had a longer reaction time in the Go condition and had a higher error ratio in both Go and NoGo conditions. The MEG analysis showed that the PD patients had a significant reduction in beta ERD during the NoGo condition and in beta ERS during both Go and NoGo conditions compared with the healthy subjects (all p < 0.05). Moreover, in the Go condition, the onsets of beta ERD and ERS were delayed in PD patients. Notably, NoGo ERS was negatively correlated with the Unified Parkinson’s Disease Rating Scale (UPDRS) score in PD patients. The present study demonstrated abnormalities in motor programming, response inhibition, and frontal inhibitory modulation in PD. Further extensive investigations are necessary to confirm the longitudinal treatment responses in PD.
Tissue-specific genes as an underutilized resource in drug discovery
Authors: Ryaboshapkina Maria , Hammar Mårten
Published: May 2019

Tissue-specific genes are believed to be good drug targets due to improved safety. Here we show that this intuitive notion is not reflected in phase 1 and 2 clinical trials, despite the historic success of tissue-specific targets and their 2.3-fold overrepresentation among targets of marketed non-oncology drugs. We compare properties of tissue-specific genes and drug targets. We show that tissue-specificity of the target may also be related to efficacy of the drug. The relationship may be indirect (enrichment in Mendelian disease and PTVesc genes) or direct (elevated betweenness centrality scores for tissue-specifically produced enzymes and secreted proteins). Reduced evolutionary conservation of tissue-specific genes may represent a bottleneck for drug projects, prompting development of novel models with smaller evolutionary gap to humans. We show that the opportunities to identify tissue-specific drug targets are not exhausted and discuss potential use cases for tissue-specific genes in drug research.
Nanoparticles in the Water–Gas Shift Reaction and Steam Reforming Reactions
Authors: Múnera J. , Faroldi B. , Cornaglia L.
Published: May 2019

This chapter focuses on a discussion of the significance of metal particle size on catalyst activity and stability for the production of hydrogen as a clean energy carrier via reforming reactions, and in particular how the particle size can influence metal oxidation and carbon formation. Numerous catalysts based on noble metals such as rhodium, platinum, iridium, palladium and ruthenium, as well as on non-noble metals such as cobalt, nickel and copper, have been studied for methane reforming, steam reforming of ethanol and the water–gas shift reaction. The design of noble and non-noble metal nanoparticles as catalysts for the production of hydrogen at different operating conditions is analysed. Several reports are discussed taking into account how the catalytic activity of metal-based materials varies with respect to the particle size. In addition, the role of metal dispersion is related to the resistance to carbon deposition and oxidation of the reduced species under reaction conditions. Correlations between the specific activity and the metal nanoparticle size have been proposed. However, the catalytic activity and the selectivity to hydrogen are highly dependent on the metal–support interactions.
Plasmonic Photocatalysts for Environmental Applications
Authors: Waters C. K. , Cojocaru B. , Lin F. , Woodard L. , Richards R. M. , Parvulescu V.
Published: May 2019

There is a continued and growing interest in sustaining and improving our environment. Research scientists are exploring new avenues using plasmonic photocatalysts as a way to catapult advances in the field. Plasmonic photocatalysts have gained significant attention in recent decades owing to the phenomena associated with localized surface plasmon resonance (LSPR). Gold (Au), silver (Ag), and copper (Cu) are the most widely studied and will be highlighted in this chapter. This chapter includes fundamental concepts related to LSPR and the significance of employing plasmons as a method to increase photocatalytic reaction rates and improve product selectivity. Plasmon-enhanced catalytic reaction types including C–X bond activation and low carbon footprint applications are highlighted in this chapter. This chapter does not include an exhaustive list of applications for which plasmonic photocatalysts can be used, but rather provides insight into the vast possibilities of how phenomena related to LSPR and plasmon-enhanced catalytic processes can have a lasting effect on how we store, use, and convert energy in chemical bonds.
Magnetic glyconanoparticles for selective lectin separation and purification
Authors: Oz Yavuz , Abdouni Yamin , Yilmaz Gokhan , Becer C. Remzi , Sanyal Amitav
Published: May 2019

A modular platform for the separation and purification of lectins using polymer coated iron oxide nanoparticles is developed.
Alpha-hemolysin nanopore allows discrimination of the microcystins variants
Authors: Júnior Janilson J. S. , Soares Thereza A. , Pol-Fachin Laércio , Machado Dijanah C. , Rusu Victor H. , Aguiar Juliana P. , Rodrigues Cláudio G.
Published: May 2019

Microcystins (MCs) are a class of cyclic heptapeptides with more than 100 variants produced by cyanobacteria present in surface waters.
Representational challenges in animated chemistry: self-generated animations as a means to encourage students’ reflections on sub-micro processes in laboratory exercises
Authors: Berg Astrid , Orraryd Daniel , Pettersson Alma Jahic , Hultén Magnus
Published: May 2019

A central aspect of learning chemistry is learning to relate observations of phenomena to models of the sub-microscopic level of matter, and hence being able to explain the observable phenomena. However, research shows that students have difficulties discerning and comprehending the meaning of the sub-micro level and its models, and that practical work in its traditional form fails to help students to discern the relation between observations and models. Consequently, there is a strong call for new teaching activities to address these issues. This paper emerges from a growing number of studies showing that learning is supported when students are set to cooperatively create their own multimodal representations of science phenomena. In this paper, we explore the approach of letting students create their own stop-motion animation as a means to explain observations during practical work. The students’ work of producing a phenomenon in the laboratory and creating an animation was recorded (audio–video) to capture students’ verbal and non-verbal interactions and use of resources. Data was analysed using a thematic content analysis with a deductive approach aimed at identifying the aspects of chemistry content that are being reasoned. The analysis showed that the task enabled students to engage in reasoning concerning both the observations and the sub-micro-level models, and how they relate to each other. The task also enabled students to reason about features of the representation that are needed to make sense of both the observational and sub-microscopic aspects of a phenomenon, as well as reflecting upon the meaning of a model.
Metal-free oxidative [2+2+1] heteroannulation of 1,7-enynes with thiocyanates toward thieno[3,4-c]quinolin-4(5H)-ones
Authors: Yu Jiang-Xi , Niu Shijie , Hu Ming , Xiang Jian-Nan , Li Jin-Heng
Published: May 2019

Transition-metal- and base-free oxidative [2+2+1] heteroannulation of 1,7-enynes with NaSCN as the sulphur source is developed.
Symmetry-guided, divergent assembly of regio-isomeric molecular Janus particles
Authors: Han Di , Shao Yu , Tao Yang-Dan , Han Ge , Zhou Dai-Lin , Yang Shuguang , Zhang Wen-Bin , Fu Qiang
Published: May 2019

Varying a single regio-configuration diverges the assembly outcome into distinct morphologies as mandated by their molecular symmetries.
New particle formation from the reactions of ozone with indene and styrene
Authors: Bracco Larisa L. B. , Tucceri María E. , Escalona Alba , Díaz-de-Mera Yolanda , Aranda Alfonso , Rodríguez Ana M. , Rodríguez Diana
Published: May 2019

SO2-Criegee intermediate reactions enhance the formation and growth of new particles in the atmosphere.
Photodissociation dynamics of CH3I probed via multiphoton ionisation photoelectron spectroscopy
Authors: Warne Emily M. , Downes-Ward Briony , Woodhouse Joanne , Parkes Michael A. , Bellshaw Darren , Springate Emma , Majchrzak Paulina , Zhang Yu , Karras Gabriel , Wyatt Adam S. , Chapman Richard T. , Kirrander Adam , Minns Russell S.
Published: May 2019

Femtosecond photoelectron spectroscopy measurements of dissociation CH3I show complex dynamics in the high energy region of absorption band A.
How do zinc oxide and zero valent iron nanoparticles impact the occurrence of antibiotic resistance genes in landfill leachate?
Authors: Shi Jianhong , Su Yinglong , Zhang Zhongjian , Wei Huawei , Xie Bing
Published: May 2019

ZnO NP exposure accelerated the dissemination of ARGs by dominantly driving changes in bacterial community, and Fe0 NP exposure promoted the attenuation of ARGs by mainly decreasing the abundances of MGEs.
Multi-tasking hydrated ionic liquids as sustainable media for the processing of waste human hair: a biorefinery approach
Authors: Singh Nripat , Prasad Kamalesh
Published: May 2019

Hydrated TBAH is able to solubilise waste human hair and melanin and keratin were isolated from the solution.
Hydrogen peroxide driven biocatalysis
Authors: Burek B. O. , Bormann S. , Hollmann F. , Bloh J. Z. , Holtmann D.
Published: May 2019

Peroxyzymes – biocatalysts utilizing environmentally benign hydrogen peroxide as a co-substrate – are a promising class of enzymes catalyzing a variety of important C–H and CC oxidations. This review critically examines recent developments in this field and the opportunities for industrial applications.
Diversification of polyketide structures via synthase engineering
Authors: Kornfuehrer Taylor , Eustáquio Alessandra S.
Published: May 2019

We present examples of polyketide structure diversification along with a perspective on the present and future of polyketide synthetic biology.
Understanding the high activity of mildly reduced graphene oxide electrocatalysts in oxygen reduction to hydrogen peroxide
Authors: Tan Xin , Tahini Hassan A. , Smith Sean C.
Published: May 2019

The direct electrochemical synthesis of hydrogen peroxide (H2O2) would provide an attractive alternative to the traditional anthraquinone oxidation process for continuous on-site applications.
Low-temperature catalytic oxidation of aniline to azoxybenzene over an Ag/Fe2O3 nanoparticle catalyst using H2O2 as an oxidant
Authors: Paul Bappi , Sharma Sachin K. , Adak Shubhadeep , Khatun Rubina , Singh Gurmeet , Das Dipak , Joshi Vedant , Bhandari Sahil , Dhar Siddhartha Sankar , Bal Rajaram
Published: May 2019

Highly dispersed Ag-supported α-Fe2O3 is found to be a recyclable and efficient catalyst for one-pot conversion of aniline to azoxybenzene.
Surface modification of Li-rich manganese-based cathode materials by chemical etching
Authors: Cui Heng , Li Hang , Liu Jiuding , Zhang Yudong , Cheng Fangyi , Chen Jun
Published: May 2019

Chemical etching modifies the surface composition of a Li-rich Mn-based cathode and generates a thin amorphous layer that stabilizes the structure.
A NiII complex of the tetradentate salen ligand H2LNH2 comprising an anchoring –NH2 group: synthesis, characterization and electrocatalytic CO2 reduction to alcohols
Authors: Bose Paulomi , Mukherjee Chandan , Golder Animes Kumar
Published: May 2019

A new salen ligand with an anchoring free amine functional group in the ligand backbone and the corresponding NiII complex [NiIILNH2] (1) were synthesized and characterized. Complex 1 electrocatalytically reduced CO2 to alcohols.
Thin layer broadband porous chromium black absorber fabricated through wet-etching process
Authors: Zhou Lang , Li Zhuo , Zhang Jinying , Li Defang , Liu Dan , Li Yajie , Wang Xin
Published: May 2019

Thin layer broadband porous Cr absorber with 93% absorption in whole visible range was fabricated on a free-standing polyimide film by wet-etching.
Metformin promotes proliferation and suppresses apoptosis in Ox-LDL stimulated macrophages by regulating the miR-34a/Bcl2 axis
Authors: Feng Liuliu , Liu Tianhua , Yang Yuya , Xiao Wenying , Shi Jun , Mei Xiang , Tian Songmei , Liu Xinbing , Huang Hongman , Bai Yanyan
Published: May 2019

Metformin, an antidiabetic drug, has been reported to be involved in atherosclerosis (AS).
Effect of polymer molecular weight on J51 based organic solar cells
Authors: Zhang Yangqian , Xu Xiangfei , Lu Jiaorong , Zhang Shiming
Published: May 2019

Very recently, organic solar cells (OSCs) have achieved outstanding scientific results with a power conversion efficiency (PCE) of over 16%.
One-step fabrication of nanosized LiFePO4/expanded graphite composites with a particle growth inhibitor and enhanced electrochemical performance of aqueous Li-ion capacitors
Authors: Lv Shixian , Zhang Xugang , Zhang Pengxue , Xiang Junyu , Li Yawen , Qiu Shen , Qin Chuanli
Published: May 2019

It is reported that olivine-type lithium iron phosphate (LFP) for Li-ion batteries is one of the most widely utilized cathode materials, but its high-power applications are limited due to its intrinsically poor ion transfer rate and conductivity.
Nonlinear electrical and rheological spectroscopies identify structural and supramolecular relaxations in a model peptide
Authors: Honorio Gabriel , Bierwirth S. Peter , Gainaru Catalin , Böhmer Roland
Published: May 2019

Nonlinear dielectric and medium-amplitude oscillatory shear experiments resolve nearby relaxations that linear spectroscopies could not separate unambiguously.
Pt-decorated hierarchical SiC nanofibers constructed by intertwined SiC nanorods for high-temperature ammonia gas sensing
Authors: Wu Nan , Wang Bing , Han Cheng , Tian Qiong , Wu Chunzhi , Zhang Xiaoshan , Sun Lian , Wang Yingde
Published: May 2019

Hierarchical Pt/HSiC nanofibers exhibited a fast response/recovery time of 2 s/5 s towards 500 ppm NH3 at 500 °C.
Enhanced air-stability of Sn-based hybrid perovskites induced by dimethylammonium (DMA): synthesis, characterization, aging and hydrogen photogeneration of the MA1−xDMAxSnBr3system
Authors: Pisanu Ambra , Speltini Andrea , Quadrelli Paolo , Drera Giovanni , Sangaletti Luigi , Malavasi Lorenzo
Published: May 2019

A novel air-stable Sn-based hybrid perovskite system, MA1−xDMAxSnBr3, system is provided.
FEZF1-AS1 functions as an oncogenic lncRNA in retinoblastoma
Authors: Quan Lian-Jiao , Wang Wen-Jun
Published: May 2019

Long non-coding RNA (lncRNA) FEZF1 antisense RNA 1 (FEZF1-AS1) has been shown to be up-regulated in tumor tissues and cells, and exerts oncogenic effects on various types of malignancies. However, the expression and function of FEZF1-AS1 was still fully unclear in retinoblastoma. The purpose of our study was to investigate the expression and clinical value of FEZF1-AS1 in retinoblastoma patients, and explore the effect of FEZF1-AS1 on retinoblastoma cell proliferation, migration and invasion. In our results, levels of FEZF1-AS1 expression were elevated in retinoblastoma tissue specimens and cell lines compared with adjacent normal retina tissue specimens and human retinal pigment epithelial cell line, respectively. The correlation analysis indicated that high FEZF1-AS1 expression was significantly correlated with present choroidal invasion and optic nerve invasion. Survival analysis suggested that retinoblastoma patients in high FEZF1-AS1 expression group had obviously short disease-free survival (DFS) compared with retinoblastoma patients in low FEZF1-AS1 expression group, and high FEZF1-AS1 expression was an independent unfavorable prognostic factor for DFS in retinoblastoma patients. Loss-of-function study indicated silencing FEZF1-AS1 expression inhibited retinoblastoma cell proliferation, invasion and migration. In conclusion, FEZF1-AS1 functions as an oncogenic lncRNA in retinoblastoma.
Parametric model for microwave filter by using multiple hidden layer output matrix extreme learning machine
Authors: Wu Shengbiao , Cao Weihua
Published: May 2019

Smart tuning of a filter depends very much on an accurate parametric model. Here, the authors develop a parametric model for a microwave filter based on an improved extreme learning machine (ELM). First, a coupling matrix is extracted from scattering parameters in undesirable states. The automatic decomposition and modular training strategy greatly reduces the network complexity. Next, by increasing the size of the output matrix of the hidden‐layer, the number of hidden layer nodes can be changed. Finally, the model parameters are optimised by combining the particle swarm optimisation (PSO) algorithm and the differential evolution (DE) algorithm. The presented parametric model benefits from the information of the fusion mechanism with a hybrid optimisation algorithm and succeeds in avoiding slow convergence and premature influence on the system. It also achieves the desired training accuracy within the target time. Compared with prediction based on back‐propagation (BP) neural networks and least‐squares support vector machines (LS‐SVMs), the proposed method can be generalised and has a better modelling accuracy.
Cherenkov Telescope Ring - An Idea for World Wide Monitoring of the VHE Sky
Authors: Ruhe Tim , Elsässer Dominik , Rhode Wolfgang , Nöthe Maximilian , Brügge Kai
Published: May 2019

With very high energy (VHE) gamma-ray astronomy becoming a mature branch of observational astrophysics, and the multi-messenger sky being opened up by neutrino observatories and gravitational wave detectors, we here propose to set up a ring of imaging air Cherenkov telescopes – the Cherenkov Telescope Ring (CTR). The aim of this proposed project would be to facilitate continuous monitoring of sources on the VHE- and multi-messenger sky with minimal time delays and with high sensitivity. Development time and construction cost could be kept comparatively low by both including existing facilities into the monitoring effort, and by relying on substantial previous expertise gained in the community on the road towards the Cherenkov Telescope Array (CTA). This way, the Ring could prove to be a highly efficient facility greatly enhancing the science prospects for future ground-based high-energy astrophysics.
Reconstruction Techniques in IceCube using Convolutional and Generative Neural Networks
Authors: Huennefeld Mirco
Published: May 2019

Reliable and accurate reconstruction methods are vital to the success of high-energy physics experiments such as IceCube. Machine learning based techniques, in particular deep neural networks, can provide a viable alternative to maximum-likelihood methods. However, most common neural network architectures were developed for other domains such as image recogntion. While these methods can enhance the reconstruction performance in IceCube, there is much potential for tailored techniques. In the typical physics use-case, many symmetries, invariances and prior knowledge exist in the data, which are not fully exploited by current network architectures. Novel and specialized deep learning based reconstruction techniques are desired which can leverage the physics potential of experiments like IceCube.

A reconstruction method using convolutional neural networks is presented which can significantly increase the reconstruction accuracy while greatly reducing the runtime in comparison to standard reconstruction methods in Ice- Cube. In addition, first results are discussed for future developments based on generative neural networks.
KM3NeT Readout and Triggering
Authors: Bruijn Ronald
Published: May 2019

The KM3NeT collaboration is constructing new-generation neutrino detectors in the Mediterranean Sea. The main goals are the study of the high-energy neutrino flux (KM3NeT/ARCA, off-shore Capo-Passero, Italy) and the determination of the neutrino mass ordering (KM3NeT/ORCA, off-shore Toulon, France). This contribution describes the system to collect, transfer and process the data, which consists of time and intensity measurements of photons recorded by photo-multiplier tubes resulting from charged products from neutrino interactions, together with data from the acoustic position system. The trigger and data-acquisition system faces the challenge of transporting up to 30 Gbps of data to shore and filtering the neutrino signal from an overwhelming (O(107)) background due to photons from ambient 40K and bioluminescence.
Time calibration of the neutrino telescope Baikal-GVD
Authors: Avrorin A.D. , Avrorin A.V. , Aynutdinov V.M. , Bannash R. , Belolaptikov I.A. , Brudanin V.B. , Budnev N.M. , Doroshenko A.A. , Domogatsky G.V. , Dvornický R. , Dyachok A.N. , Dzhilkibaev Zh.-A.M. , Fajt L. , Fialkovsky S.V. , Gafarov A.R. , Golubkov K.V. , Gorshkov N.S. , Gres T.I. , Kebkal K.G. , Kebkal O.G. , Khramov E.V. , Kolbin M.M. , Konischev K.V. , Korobchenko A.P. , Koshechkin A.P. , Kozhin V.A. , Kruglov M.V. , Kryukov M.K. , Kulepov V.F. , Kuleshov D.A. , Milenin M.B. , Mirgazov R.A. , Nazari V. , Panfilov A.I. , Petukhov D.P. , Pliskovsky E.N. , Rozanov M.I. , Rjabov E.V. , Rushay V. D. , Safronov G.B. , Shaibonov B.A. , Šimkovic F. , Shelepov M.D. , Shtekl I. , Solovjev A.G. , Sorokovikov M.N. , Suvorova O.V. , Tabolenko V.A. , Tarashansky B.A. , Yakovlev S.A. , Zagorodnikov A.V.
Published: May 2019

Baikal-GVD is a cubic-kilometer scale neutrino telescope, which is currently under construction in Lake Baikal. Baikal-GVD is an array of optical modules arranged in clusters. The first cluster of the array has been deployed and commissioned in April 2015. To date, Baikal-GVD consists of 3 clusters with 864 optical modules. One of the vital conditions for optimal energy, position and direction reconstruction of the detected particles is the time calibration of the detector. In this article, we describe calibration equipment and methods used in Baikal-GVD and demonstrate the accuracy of the calibration procedures.
NEVOD as a test facility for future neutrino telescopes
Authors: Petrukhin A.A. , Khokhlov S.S.
Published: May 2019

The possibility to calibrate the new optical modules mDOM of the IceCube-Upgrade neutrino telescope inside the tank of Cherenkov water detector NEVOD is discussed. Methods to calibrate optical modules are presented. The spatial lattice of the detector NEVOD and deployed outside of the water tank calibration telescope system and coordinate-tracking detector DECOR allow calibrating the response of mDOM with respect to the Cherenkov light from muons, muon bundles and cascades with known trajectories.
Telescope Array Hybrid Composition and Auger-TA Composition Comparison
Authors: Hanlon William
Published: May 2019

Telescope Array (TA) has completed analysis of nearly nine years of data measuring the atmospheric depth of air shower maximum (Xmax) utilizing the TA surface detector array and the Black Rock Mesa and Long Ridge fluorescence detector stations. By using both the surface array and the fluorescence detector, the geometry and arrival time of air showers can be measured very precisely providing good resolution in determining Xmax. Xmax is directly related to the air shower primary particle mass and is therefore important for understanding the composition of ultra high energy cosmic rays (UHECRs). UHECR composition will help answer questions such as the distance and location of their sources. We discuss the experimental apparatus, analysis method, and Xmax data collected. We compare the energy dependent distributions of the observed data to detailed Monte Carlo simulations of four chemical species, then test which individual species are not compatible with the data through an analysis of the shapes of the distributions. We also discuss the present state of composition analysis and interpretation between the Auger and TA experiments. These are the two largest UHECR observatories in the world with large exposures and should shed light on UHECR composition.
Hadronic Interactions and Air Showers: Where Do We Stand?
Authors: Pierog Tanguy
Published: May 2019

The interpretation of EAS measurements strongly depends on detailed air shower simulations. CORSIKA is one of the most commonly used air shower Monte Carlo programs. The main source of uncertainty in the prediction of shower observables for different primary particles and energies is currently dominated by differences between hadronic interaction models even after recent updates taking into account the first LHC data. As a matter of fact the model predictions converged but at the same time more precise air shower and LHC measurements introduced new constraints. Last year a new generation of hadronic interaction models was released in CORSIKA. Sibyll 2.3c and DPMJETIII.17-1 are now available with improved descriptions of particle production and in particular the production of charmed particles. The impact of these hadronic interaction models on air shower predictions are presented here and compared to the first generation of post-LHC models, EPOS LHC and QGSJETII-04. The performance of the new models on standard air shower observables is derived. Due to the various approaches in the physics treatment, there are still large differences in the model predictions but this can already be partially resolved by comparison with the latest LHC data.
Exotic model of the cosmic ray spectrum
Authors: Shaulov Sergey
Published: May 2019

A detailed study of the cores of extensive air showers (EAS) at mountain level (Tien-Shan 690 g/cm2) was carried out in the hybrid experiment HADRON. An analysis of the fine structure of the EAS spectrum in the energy region1015- 1017(knee) showed that there are two breaks in the spectrum. Along with the previously known break at an energy of 3 · 1015eV, a change in the slope of the EAS spectrum is observed at an energy slightly below 1017eV. In addition the use of a large X-ray emulsion chamber (XREC) as a detector of EAS cores allowed us to obtain several new results. An abnormal scaling violation in hadron spectra for Ne~ 107(E0~ 1016eV) means the existence of a penetrating component of non-nuclear origin. The conclusion about the non-nuclear origin of the penetrating component in the primary radiation of CR is confirmed by the data about the excess of muons in the EAS containing hadrons of maximum energies. It is assumed that the mass composition of primary cosmic radiation varies sharply at energies of 1015- 1016eV, where quasi-nuclei (strangelets) appear instead of nuclei. A new model of the mass composition of cosmic rays in the region of ultrahigh energies is proposed on this basis .
Can strangelets solve the muon puzzle?
Authors: Rybczyński Maciej , Włodarczyk Zbigniew
Published: May 2019

In order to examine a muon excess observed by the Pierre Auger Observatory, detailed Monte Carlo simulations were carried out, assuming the existence of strangelets (hypothetical stable lumps of strange quark matter) in the primary cosmic rays. We obtain a rough agreement between the simulations and the data for ordinary nuclei without any contribution of strangelets in the primary flux of cosmic rays.
Extensive Air Showers with Unusual Spatial and Temporal Structure
Authors: Beisembaev Rashid , Beznosko Dmitriy , Baigarin Kanat , Batyrkhanov Ayan , Beisembaeva Elena , Dalkarov Oleg , Iakovlev Alexander , Ryabov Vladimi , Sadykov Turlan , Shaulov Sergei , Vildanova Marina , Uakhitov Tileubek , Zhukov Valeriy
Published: May 2019

The Extensive Air Shower (EAS) data collected by the Horizon-10T detector system has numerous events exhibiting the unusual spatial and temporal structure. These are events typically with two to four pulses of tens of ns wide that are present at distances above 300 m from the EAS axis, with these pulses being delayed by hundreds of ns. Each of such pulse groups were registered simultaneously by several detectors separated by up to a km from each other. The detectors brief overview and the analysis of simulated EAS by the CORSIKA software package are given in this article. The analysis indicates that such events with unusual structure cannot be formed by showers with EM and hadronic components only. This indicates a possibility for a new process observation beyond the standard model description in the energy range above ~1018 eV.
Study of themuon content of high-energy air showers with KASCADE-Grande
Authors: Arteaga-Velázquez J.C. , Rivera-Rangel D. , Apel W.D. , Bekk K. , Bertaina M. , Blümer J. , Bozdog H. , Brancus I.M. , Cantoni E. , Chiavassa A. , Cossavella F. , Daumiller K. , de Souza V. , Di Pierro F. , Doll P. , Engel R. , Fuhrmann D. , Gherghel-Lascu A. , Gils H.J. , Glasstetter R. , Grupen C. , Haungs A. , Heck D. , Hörandel J.R. , Huege T. , Kampert K.H. , Kang D. , Klages H.O. , Link K. , Łuczak P. , Mathes H.J. , Mayer H.J. , Milke J. , Mitrica B. , Morello C. , Oehlschläger J. , Ostapchenko S. , Pierog T. , Rebel H. , Roth M. , Schieler H. , Schoo S. , Schröder F.G. , Sima O. , Toma G. , Trinchero G.C. , Ulrich H. , Weindl A. , Wochele J. , Zabierowski J.
Published: May 2019

In this work, we report measurements on the muon content (Eth > 230 MeV) of extensive air showers (EAS) induced by cosmic rays with primary energy from 10 PeV up to 1 EeV performed with the KASCADE-Grande experiment. The measurements are confronted with SIBYLL 2.3. The results are focused on the dependence of the total muon number and the lateral density distribution of muons in EAS on the zenith angle and the total number of charged particles in the shower. We also present updated results of a detailed study of the attenuation length of shower muons, which reveal a deviation between the measured data and the predictions of the post-LHC hadronic interaction models SIBYLL 2.3, QGSJET-II-04 and EPOS-LHC.
High-energy neutrino-nucleus interactions
Authors: Kumano Shunzo
Published: May 2019

High-energy neutrino-nucleus interactions are discussed by considering neutrino-oscillation experiments and ultra-high-energy cosmic neutrino interactions. The largest systematic error for the current neutrino oscillation measurements comes from the neutrino-nucleus interaction part, and its accurate understanding is essential for high-precision neutrino physics, namely for studying CP violation in the lepton sector. Depending on neutrino beam energies, quasi-elastic, resonance, Regge, or/and deep inelastic scattering (DIS) processes contribute to the neutrino cross section. It is desirable to have a code to calculate the neutrino-nucleus cross section in any kinematical range by combining various theoretical descriptions. On the other hand, the IceCube collaboration started obtaining cross section data up to the 1015 eV range, so that it became necessary to understand ultra-high-energy neutrino interactions beyond the artificial lepton-accelerator energy range. For future precise neutrino physics including the CP measurement, it is also necessary to understand accurate nuclear corrections. The current status is explained for nuclear corrections in DIS structure functions. The possibility is also discussed to find gravitational sources within nucleons and nuclei, namely matrix elements of quark-gluon energy-momentum tensor. They could be probed by neutrino interactions without replying on direct ultra-weak “gravitational interactions” with high-intensity neutrino beams, possibly at a future neutrino factory, by using techniques of hadron tomography.
Performance of the Horizon-10T detector system in Physics Run 1
Authors: Beisembaev Rashid , Beznosko Dmitriy , Baigarin Kanat , Batyrkhanov Ayan , Beisembaeva Elena , Dalkarov Oleg , Iakovlev Alexander , Ryabov Vladimi , Sadykov Turlan , Shaulov Sergei , Vildanova Marina , Uakhitov Tileubek , Zhukov Valeriy
Published: May 2019

This article overviews the performance of the Horizon-10T (H10T) detector system in Physics Run 1. The upgraded H10T detector system consists of ten charged particle detection points, separated by distances from a hundred meters up to 1.3 kilometer and is able to detect disks in primary particle energy ranges of 1016-1019 eV and zenith angles from 0° to 85° with a few ns precision.
Simulation of the fluorescence signal detected by a space telescope for extreme energy cosmic ray observations
Authors: Bouhali Zohra , Djemil Taoufik
Published: May 2019

The experimental technique of fluorescence light measurement is used for indirect observations of cosmic ray particles at very high energies. Extensive Air Showers (EAS) initiated by Extreme Energy Cosmic Rays (EECRs), up to 100 EeV and entering the Earth’s atmosphere, are simulated with the CORSIKA package. The influence of different simulation parameters on the EAS characteristics is studied, especially on the longitudinal distribution of charged particles, depth of shower maximum and energy released to the air. By taking the atmospheric scattering of light into account, the number of fluorescence photons, with wavelengths between 300-430 nm, and their arrival time distribution to an ideal space telescope are calculated.
Observation of Properties of Primary and Secondary Cosmic Rays by the Alpha Magnetic Spectrometer on the International Space Station
Authors: Oliva Alberto
Published: May 2019

The Alpha Magnetic Spectrometer (AMS-02) is a wide acceptance high-energy physics experiment installed on the International Space Station in May 2011 and operating continuously since then. With a collection rate of approximately 1.7 × 1010 events/year, and the combined identification capabilities of 5 independent detectors, AMS-02 is able to precisely separate cosmic rays light nuclei (1 ≤ Z ≤ 8). Knowledge of the precise rigidity dependence of the light nuclei fluxes is important in understanding the origin, acceleration, and propagation of cosmic rays. AMS-02 collaboration has recently released the precise measurements of the fluxes of light nuclei as a function of rigidity (momentum/charge) in the range between 2 GV and 3 TV. Based on the observed spectral behaviour, the light nuclei can be separated in three distinct families: primaries (hydrogen, helium, carbon, and oxygen), secondaries (lithium, beryllium, and boron), and mixed (nitrogen). Spectral indices of all light nuclei fluxes progressively harden above 100 GV. Primary cosmic ray fluxes have an identical hardening above 60 GV, of about γ = 0.12 ± 0.04. While helium, carbon and oxygen have identical spectral index magnitude, the hydrogen spectral index shows a different magnitude, i.e. the primary-to-primary H/He ratio is well described by a single power law above 45 GV with index -0.077 ± 0.007. Secondary cosmic ray fluxes have identical rigidity dependence above 30 GV. Secondary cosmic rays all harden more than primary species, and together all secondary-to-primary ratios show a hardening difference of 0.13 ± 0.03. Remarkably, the nitrogen flux is well described over the entire rigidity range by the sum of the primary flux equal to 9% of the oxygen flux and the secondary flux equal to 62% of the boron flux.
Measurement of knees of the spectra of heavy nuclei above 10 PeV with LHAASO
Authors: Cao Z. , Ma L.L. , Zhang S.S. , Wang C. , Yin L.Q. , Bi B.Y.
Published: May 2019

Measuring the knees of the cosmic ray spectra for individual species is a very important approach to solve the problem of the origin of ultra high energy galactic cosmic rays. The knee of the iron spectrum is implied to be above 10 PeV from previous experiments, such as ARGO-YBJ and LHAASO-WFCTA. LHAASO is a suitable size for measurements with the required precision. The key is to separate iron nuclei from all cosmic ray samples. In this paper, we identify a couple of variables that are sensitive to the composition of showers recorded by the detector arrays in LHAASO. A multi variate analysis is proposed for the separation. The efficiency and purity of the selection for demanded species are optimized by well configuring the LHAASO array using the LHAASO simulation tools.
Galactic Cosmic Rays: The first detection of TeV gamma-rays from Red Dwarfs
Authors: Sinitsyna V.G. , Sinitsyna V.Y. , Stozhkov Yu.I.
Published: May 2019

The present point of view on the sources of cosmic rays in Galaxy considers explosions of supernovae as sources of these particles up to energies of 1017 eV. However, the experimental data obtained with Pamela, Fermi, AMS-02 spectrometers requires the existence of nearby sources of cosmic rays at distances less then 1 kpc from the solar system. These sources could explain such experimental data as the growth of the ratio of galactic positrons to electrons with increasing energy, the complex dependence of the exponent of the proton and alpha spectra from the energy of these particles, the appearance of an anomaly component in cosmic rays. We consider active dwarf stars as possible sources of galactic cosmic rays in the energy range up to 1014 eV. These stars produce powerful stellar flares. The generation of high-energy cosmic rays has to be accompanied by high-energy gamma-ray emission. Here we present the SHALON long-term observation data aimed at searching for gamma-ray emission above 800 GeV from active red dwarf stars. The data obtained during more than 10 years observations of the dwarf stars V962 Tau, V780 Tau, V388 Cas and V1589 Cyg were analyzed. The high-energy gamma-ray emission in the TeV energy range, mostly of the flaring type from the sources mentioned above, was detected. This result confirms that active dwarf stars are also the sources of high-energy galactic cosmic rays.