bluuebunny/crossref_metadata_2025 huggingface dataset:
Photo-acoustic dual-frequency comb spectroscopy
Authors: Wildi Thibault , Voumard Thibault , Brasch Victor , Yilmaz Gürkan , Herr Tobias
Published: August 2020

Photo-acoustic spectroscopy (PAS) is one of the most sensitive non-destructive analysis techniques for gases, fluids and solids. It can operate background-free at any wavelength and is applicable to microscopic and even non-transparent samples. Extension of PAS to broadband wavelength coverage is a powerful tool, though challenging to implement without sacrifice of wavelength resolution and acquisition speed. Here we show that dual-frequency comb spectroscopy (DCS) and its potential for unmatched precision, speed and wavelength coverage can be combined with the advantages of photo-acoustic detection. Acoustic wave interferograms are generated in the sample by dual-comb absorption and detected by a microphone. As an example, weak gas absorption features are precisely and rapidly sampled; long-term coherent averaging further increases the sensitivity. This novel approach of dual-frequency comb photo-acoustic spectroscopy (DCPAS) generates unprecedented opportunities for rapid and sensitive multi-species molecular analysis across all wavelengths of light.
Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes
Authors: Chu Zema , Zhao Yang , Ma Fei , Zhang Cai-Xin , Deng Huixiong , Gao Feng , Ye Qiufeng , Meng Junhua , Yin Zhigang , Zhang Xingwang , You Jingbi
Published: August 2020

Perovskite light-emitting diodes (PeLEDs) have showed significant progress in recent years; the external quantum efficiency (EQE) of electroluminescence in green and red regions has exceeded 20%, but the efficiency in blue lags far behind. Here, a large cation CH3CH2NH2+ is added in PEA2(CsPbBr3)2PbBr4 perovskite to decrease the Pb–Br orbit coupling and increase the bandgap for blue emission. X-ray diffraction and nuclear magnetic resonance results confirmed that the EA has successfully replaced Cs+ cations to form PEA2(Cs1-xEAxPbBr3)2PbBr4. This method modulates the photoluminescence from the green region (508 nm) into blue (466 nm), and over 70% photoluminescence quantum yield in blue is obtained. In addition, the emission spectra is stable under light and thermal stress. With configuration of PeLEDs with 60% EABr, as high as 12.1% EQE of sky-blue electroluminescence located at 488 nm has been demonstrated, which will pave the way for the full color display for the PeLEDs.
Magnetic field detection limits for ultraclean graphene Hall sensors
Authors: Schaefer Brian T. , Wang Lei , Jarjour Alexander , Watanabe Kenji , Taniguchi Takashi , McEuen Paul L. , Nowack Katja C.
Published: August 2020

Solid-state magnetic field sensors are important for applications in commercial electronics and fundamental materials research. Most magnetic field sensors function in a limited range of temperature and magnetic field, but Hall sensors in principle operate over a broad range of these conditions. Here, we evaluate ultraclean graphene as a material platform for high-performance Hall sensors. We fabricate micrometer-scale devices from graphene encapsulated with hexagonal boron nitride and few-layer graphite. We optimize the magnetic field detection limit under different conditions. At 1 kHz for a 1 μm device, we estimate a detection limit of 700 nT Hz−1/2 at room temperature, 80 nT Hz−1/2 at 4.2 K, and 3 μT Hz−1/2 in 3 T background field at 4.2 K. Our devices perform similarly to the best Hall sensors reported in the literature at room temperature, outperform other Hall sensors at 4.2 K, and demonstrate high performance in a few-Tesla magnetic field at which the sensors exhibit the quantum Hall effect.
Evidence that the TRPV1 S1-S4 membrane domain contributes to thermosensing
Authors: Kim Minjoo , Sisco Nicholas J. , Hilton Jacob K. , Montano Camila M. , Castro Manuel A. , Cherry Brian R. , Levitus Marcia , Van Horn Wade D.
Published: August 2020

Sensing and responding to temperature is crucial in biology. The TRPV1 ion channel is a well-studied heat-sensing receptor that is also activated by vanilloid compounds, including capsaicin. Despite significant interest, the molecular underpinnings of thermosensing have remained elusive. The TRPV1 S1-S4 membrane domain couples chemical ligand binding to the pore domain during channel gating. Here we show that the S1-S4 domain also significantly contributes to thermosensing and couples to heat-activated gating. Evaluation of the isolated human TRPV1 S1-S4 domain by solution NMR, far-UV CD, and intrinsic fluorescence shows that this domain undergoes a non-denaturing temperature-dependent transition with a high thermosensitivity. Further NMR characterization of the temperature-dependent conformational changes suggests the contribution of the S1-S4 domain to thermosensing shares features with known coupling mechanisms between this domain with ligand and pH activation. Taken together, this study shows that the TRPV1 S1-S4 domain contributes to TRPV1 temperature-dependent activation.
Effects of a herbal formulation, KGC3P, and its individual component, nepetin, on coal fly dust-induced airway inflammation
Authors: Saba Evelyn , Lee Young-sil , Yang Won-Kyung , Lee Yuan Yee , Kim MinKi , Woo Su-Min , Kim KilSoo , Kwon Young-Sam , Kim Tae-Hwan , Kwak Dongmi , Park Yang-Chun , Shin Han Jae , Han Chang Kyun , Oh Jae-Wook , Lee Young Cheol , Kang Hyung-Sik , Rhee Man Hee , Kim Seung-Hyung
Published: August 2020

Coal fly dust (CFD)-induced asthma model is used as an ambient particulate matter model of serious pulmonary damage. We aimed to evaluate the effects of a combination of ginseng and Salvia plebeia R. Br extract (KGC-03-PS; KG3P) and its individual components (hispidulin, nepetin and rosmarinic acid) in a CFD-induced mouse model of airway inflammation (asthma). We also evaluated signal transduction by KG3P and its individual components in the alveolar macrophage cell line, MH-S cells. In vitro, KG3P and its individual components inhibited nitric oxide production and expression of pro-inflammatory mediators and cytokines (iNOS, COX-2, IL-1β, IL-6 and TNF-α) through the NF-κB and MAPK pathways in coal fly ash (CFA)-induced inflammation in MH-S cells. Moreover, in the CFD-induced asthma model in mice, KG3P and its predominant individual component, nepetin, inhibited Asymmetric Dimethyl arginine (ADMA) and Symmetric Dimethyl arginine (SDMA) in serum, and decreased the histopathologic score in the lungs. A significant reduction in the neutrophils and immune cells in BALF and lung tissue was demonstrated, with significant reduction in the expression of the pro-inflammatory cytokines. Finally, IRAK-1 localization was also potently inhibited by KG3P and nepetin. Thus, KG3P extract can be considered as a potent candidate for amelioration of airway inflammation.
Innovative low-cost biosorption process of Cr6+ by Pseudomonas alcaliphila NEWG-2
Authors: El-Naggar Noura El-Ahmady , El-khateeb Ayman Y. , Ghoniem Abeer Abdulkhalek , El-Hersh Mohammed S. , Saber WesamEldin I. A.
Published: August 2020

Chromium is one of the heavy metal pollutants that causing risky health issues when discharged into the aquatic ecosystems. The current investigation focused on the bioremoval of Cr6+ depending on the bacterial sorption process by using Pseudomonas sp. NEWG-2 which was identified on the basis of morphological, cultural characteristics, 16S rRNA sequencing and phylogenetic analysis as Pseudomonas alcaliphila strain NEWG-2. It is clear from the FCCD experiments that the bacterium can grow normally and remove 96.60% of 200 mg/l of Cr6+ using yeast extract (5.6 g/l), glucose (4.9 g/l), pH (7) for 48 h incubation period. SEM and EDS analyses proved that the Cr6+ was biosorbed by P. alcaliphila NEWG-2. FTIR spectra indicated that the phenolic, carbonyl ester, acetyl, carboxylate, alkanes and carbonyl were the main groups involved in the chromium biosorption. Of the equilibrium isotherms models, the Langmuir model was more obedient, with a maximum uptake (qmax) of 10 mg/g (bacterial-alginate beads), than the Freundlich one. The findings reveal the efficiency of P. alcaliphila NEWG-2 in Cr6+ biosorption, with feasibility in the treatment of chromium-contaminated water as a green-technology tool. Interestingly, to the best of our knowledge, this is the first report on Cr6+ biosorption process by P. alcaliphila.
Homozygous deletions implicate non-coding epigenetic marks in Autism spectrum disorder
Authors: Schmitz-Abe Klaus , Sanchez-Schmitz Guzman , Doan Ryan N. , Hill R. Sean , Chahrour Maria H. , Mehta Bhaven K. , Servattalab Sarah , Ataman Bulent , Lam Anh-Thu N. , Morrow Eric M. , Greenberg Michael E. , Yu Timothy W. , Walsh Christopher A. , Markianos Kyriacos
Published: August 2020

More than 98% of the human genome is made up of non-coding DNA, but techniques to ascertain its contribution to human disease have lagged far behind our understanding of protein coding variations. Autism spectrum disorder (ASD) has been mostly associated with coding variations via de novo single nucleotide variants (SNVs), recessive/homozygous SNVs, or de novo copy number variants (CNVs); however, most ASD cases continue to lack a genetic diagnosis. We analyzed 187 consanguineous ASD families for biallelic CNVs. Recessive deletions were significantly enriched in affected individuals relative to their unaffected siblings (17% versus 4%,p < 0.001). Only a small subset of biallelic deletions were predicted to result in coding exon disruption. In contrast, biallelic deletions in individuals with ASD were enriched for overlap with regulatory regions, with 23/28 CNVs disrupting histone peaks in ENCODE (p < 0.009). Overlap with regulatory regions was further demonstrated by comparisons to the 127-epigenome dataset released by the Roadmap Epigenomics project, with enrichment for enhancers found in primary brain tissue and neuronal progenitor cells. Our results suggest a novel noncoding mechanism of ASD, describe a powerful method to identify important noncoding regions in the human genome, and emphasize the potential significance of gene activation and regulation in cognitive and social function.
Recombinant Plasmodium vivax circumsporozoite surface protein allelic variants: antibody recognition by individuals from three communities in the Brazilian Amazon
Authors: Soares Isabela Ferreira , López-Camacho César , Rodrigues-da-Silva Rodrigo Nunes , da Silva Matos Ada , de Oliveira Baptista Barbara , Totino Paulo Renato Rivas , de Souza Rodrigo Medeiros , Harrison Kate , Gimenez Alba Marina , de Freitas Elisângela Oliveira , Kim Young Chan , Oliveira-Ferreira Joseli , Daniel-Ribeiro Cláudio Tadeu , Reyes-Sandoval Arturo , Pratt-Riccio Lilian Rose , Lima-Junior Josué da Costa
Published: August 2020

Circumsporozoite protein (CSP) variants of P. vivax, besides having variations in the protein repetitive portion, can differ from each other in aspects such as geographical distribution, intensity of transmission, vectorial competence and immune response. Such aspects must be considered to P. vivax vaccine development. Therefore, we evaluated the immunogenicity of novel recombinant proteins corresponding to each of the three P. vivax allelic variants (VK210, VK247 and P. vivax-like) and of the C-terminal region (shared by all PvCSP variants) in naturally malaria-exposed populations of Brazilian Amazon. Our results demonstrated that PvCSP-VK210 was the major target of humoral immune response in studied population, presenting higher frequency and magnitude of IgG response. The IgG subclass profile showed a prevalence of cytophilic antibodies (IgG1 and IgG3), that seem to have an essential role in protective immune response. Differently of PvCSP allelic variants, antibodies elicited against C-terminal region of protein did not correlate with epidemiological parameters, bringing additional evidence that humoral response against this protein region is not essential to protective immunity. Taken together, these findings increase the knowledge on serological response to distinct PvCSP allelic variants and may contribute to the development of a global and effective P. vivax vaccine.
Machine learning-based automated classification of headache disorders using patient-reported questionnaires
Authors: Kwon Junmo , Lee Hyebin , Cho Soohyun , Chung Chin-Sang , Lee Mi Ji , Park Hyunjin
Published: August 2020

Classification of headache disorders is dependent on a subjective self-report from patients and its interpretation by physicians. We aimed to apply objective data-driven machine learning approaches to analyze patient-reported symptoms and test the feasibility of the automated classification of headache disorders. The self-report data of 2162 patients were analyzed. Headache disorders were merged into five major entities. The patients were divided into training (n = 1286) and test (n = 876) cohorts. We trained a stacked classifier model with four layers of XGBoost classifiers. The first layer classified between migraine and others, the second layer classified between tension-type headache (TTH) and others, and the third layer classified between trigeminal autonomic cephalalgia (TAC) and others, and the fourth layer classified between epicranial and thunderclap headaches. Each layer selected different features from the self-reports by using least absolute shrinkage and selection operator. In the test cohort, our stacked classifier obtained accuracy of 81%, sensitivity of 88%, 69%, 65%, 53%, and 51%, and specificity of 95%, 55%, 46%, 48%, and 51% for migraine, TTH, TAC, epicranial headache, and thunderclap headaches, respectively. We showed that a machine-learning based approach is applicable in analyzing patient-reported questionnaires. Our result could serve as a baseline for future studies in headache research.
RhCMV serostatus and vaccine adjuvant impact immunogenicity of RhCMV/SIV vaccines
Authors: Chang W. L. William , Deere Jesse D. , Kieu Hung T. , Castillo Luis D. , Machmach Kawthar , Shen Xiaoying , Tomaras Georgia D. , Shacklett Barbara L. , Barry Peter A. , Hartigan-O’Connor Dennis J. , Sparger Ellen E.
Published: August 2020

Rhesus cytomegalovirus (RhCMV) strain 68-1-vectored simian immunodeficiency virus (RhCMV/SIV) vaccines are associated with complete clearance of pathogenic SIV challenge virus, non-canonical major histocompatibility complex restriction, and absent antibody responses in recipients previously infected with wild-type RhCMV. This report presents the first investigation of RhCMV/SIV vaccines in RhCMV-seronegative macaques lacking anti-vector immunity. Fifty percent of rhesus macaques (RM) vaccinated with a combined RhCMV-Gag, -Env, and -Retanef (RTN) vaccine controlled pathogenic SIV challenge despite high peak viremia. However, kinetics of viral load control by vaccinated RM were considerably delayed compared to previous reports. Impact of a TLR5 agonist (flagellin; FliC) on vaccine efficacy and immunogenicity was also examined. An altered vaccine regimen containing an SIV Gag-FliC fusion antigen instead of Gag was significantly less immunogenic and resulted in reduced protection. Notably, RhCMV-Gag and RhCMV-Env vaccines elicited anti-Gag and anti-Env antibodies in RhCMV-seronegative RM, an unexpected contrast to vaccination of RhCMV-seropositive RM. These findings confirm that RhCMV-vectored SIV vaccines significantly protect against SIV pathogenesis. However, pre-existing vector immunity and a pro-inflammatory vaccine adjuvant may influence RhCMV/SIV vaccine immunogenicity and efficacy. Future investigation of the impact of pre-existing anti-vector immune responses on protective immunity conferred by this vaccine platform is warranted.
Kinetics and adsorption calculations: insights into the MgO-catalyzed detoxification of simulants of organophosphorus biocides
Authors: Almerindo Gizelle I. , Buratto Suelen C. , Wanderlind Eduardo H. , Nicolazi Lucas M. , Sangaletti Patrícia , Medeiros Michelle , Schneider Felipe S. S. , Caramori Giovanni F. , Parreira Renato L. T. , Micke Gustavo A. , Fiedler Haidi D. , Nome Faruk
Published: August 2020

Optimization of the catalytic detoxification of a toxic organophosphorus biocide employing a simple metal oxide.
Aligned collagen scaffold combination with human spinal cord-derived neural stem cells to improve spinal cord injury repair
Authors: Zou Yunlong , Ma Dezun , Shen He , Zhao Yannan , Xu Bai , Fan Yongheng , Sun Zheng , Chen Bing , Xue Weiwei , Shi Ya , Xiao Zhifeng , Gu Rui , Dai Jianwu
Published: August 2020

Neural stem/progenitor cell (NSPC)-based spinal cord injury (SCI) therapy is expected to bridge the lesion site by transplanting exogenous NSPCs for replacement of lost cells.
Three-component D–A hybrid heterostructures with enhanced photochromic, photomodulated luminescence and selective anion-sensing properties
Authors: Li Meng-Hua , Lv Shu-Li , You Ming-Hua , Lin Mei-Jin
Published: August 2020

Three novel three-component hybrid heterostructures with inorganic [CoIII(CN)6]3− anions as electron donors and viologen tectons as electron acceptors exhibit combined properties of photochromism, photomodulated luminescence and anion sensing.
Correction: A facile template-free synthesis of Bi2Sn2O7 with flower-like hierarchical architecture for enhanced visible-light photocatalytic activity
Authors: Wu Chenyan , Shen Qianhong , Yu LiXin , Huang Feilong , Zhang Changteng , Sheng Jiansong , Zhang Fang , Cheng Di , Yang Hui
Published: August 2020

Correction for ‘A facile template-free synthesis of Bi2Sn2O7 with flower-like hierarchical architecture for enhanced visible-light photocatalytic activity’ by Chenyan Wu et al., New J. Chem., 2020, 44, 11196–11202, DOI: 10.1039/D0NJ01690J.
A thieno-isoindigo derivative-based conjugated polymer nanoparticle for photothermal therapy in the NIR-II bio-window
Authors: Wei Zuwu , Xue Fangqin , Xin Fuli , Wu Ming , Wang Bingxi , Zhang Xiaolong , Yang Sen , Guo Zhiyong , Liu Xiaolong
Published: August 2020

Here, a thieno-isoindigo derivative-based Donor–Acceptor (D–A) polymer, which exhibited excellent absorption characteristics from the NIR-I to NIR-II window, was prepared for photothermal therapy.
N-Primary-amine tetrapeptide-catalyzed highly asymmetric Michael addition of aliphatic aldehydes to maleimides
Authors: Du Zhi-Hong , Qin Wen-Juan , Tao Bao-Xiu , Yuan Meng , Da Chao-Shan
Published: August 2020

The highly asymmetric Michael addition reaction between maleimides and aldehydes catalyzed by N-primary-amine β-turn tetrapeptides with excellent yields and enantioselectivities was reported.
Deep eutectic solvent as solvent and catalyst: one-pot synthesis of 1,3-dinitropropanesviatandem Henry reaction/Michael addition
Authors: Colombo Dugoni Greta , Sacchetti Alessandro , Mele Andrea
Published: August 2020

1,3-Dinitropropane derivatives were obtained in a simple one-pot procedure from nitromethane and aromatic aldehydes by combining MW irradiation and the use of DES as both catalyst and solvent.
Uncovering the role of Ag in layer-alternating Ni3S2/Ag/Ni3S2 as an electrocatalyst with enhanced OER performance
Authors: Guo Rui , He Yan , Wang Renchao , You Junhua , Lin Hongji , Chen Chiente , Chan Tingshan , Liu Xuanwen , Hu Zhiwei
Published: August 2020

It is increasingly important to develop an efficient OER catalyst that can provide high current density at low overpotentials to improve water splitting efficiency.
NBS-activated cross-dehydrogenative esterification of carboxylic acids with DMSO
Authors: Wu Ya , Zhang Mengsha , Zhang Yanli , Li Mingyang , Feng Weisheng , Zheng Xiaoke , Tang Lin
Published: August 2020

A convenient and versatile cross-dehydrogenative esterification of carboxylic acids with DMSO for preparing (methylsulfinyl)methyl esters has been developed in the presence of N-bromosuccinimide.
From a 1,2-azaborinine to largeBN-PAHsviaelectrophilic cyclization: synthesis, characterization and promising optical properties
Authors: Appiarius Yannik , Stauch Tim , Lork Enno , Rusch Pascal , Bigall Nadja C. , Staubitz Anne
Published: August 2020

A synthetic approach towards boron-nitrogen substituted polycyclic aromatic hydrocarbons (BN-PAHs)viaelectrophilic cyclization is described and it is shown that the variation of the rings' connectivity may tune the emission wavelengths effectively.
Influence of surface coating on the microstructures and dielectric properties of BaTiO3 ceramic via a cold sintering process
Authors: Kang Shenglin , Guo Hongxia , Wang Jinbin , Zhong Xiangli , Li Bo
Published: August 2020

Surface coating facilitates to dissolution–precipitation process and improves the dielectric properties of barium titanate ceramics during cold sintering process.
Resolving charge-transfer and mass-transfer processes of VO2+/VO2+redox species across the electrode/electrolyte interface using electrochemical impedance spectroscopy for vanadium redox flow battery
Authors: Leuaa Pradipkumar , Priyadarshani Divya , Choudhury Debittree , Maurya Rajan , Neergat Manoj
Published: August 2020

Effect of redox species concentration across the electrode/electrolyte interface on the EIS features.
From CO2 activation to catalytic reduction: a metal-free approach
Authors: P. Sreejyothi , Mandal Swadhin K.
Published: August 2020

This review article documents the key developments in the metal-free catalytic reduction of CO2 into various energy intensive chemicals and fuels, and reductive functionalization of CO2 for the formation of new C–N bonds.
Understanding the binary interactions of noble metal and semiconductor nanoparticles
Authors: Yadav Hari O. S.
Published: August 2020

The characterization of fluctuation-driven anisotropy in the pair interactions of passivated gold and CdSe nanoparticles.
Monte Carlo simulations of patch models with applications to soft matter
Authors: Gaughran S. K. , Rickman J. M. , Haaga J. , Gunton J. D.
Published: August 2020

We present a unified study of two soft matter systems to assess how anisotropy and polydispersity affect self-assembly.
High performance cyano-substituted quinoxaline-based polymers for both fullerene and nonfullerene polymer solar cells
Authors: Handoko Shinta Lieviana , Jeong Mijin , Whang Dong Ryeol , Kim Joo Hyun , Chang Dong Wook
Published: August 2020

This research can offer not only the first direct comparisons between F and CN substituents on the photovoltaic properties but also the highest PCEs among the reported CN-substituted polymers in both categories of fullerene and nonfullerene PSCs.
Origin of thermally activated delayed fluorescence in a donor–acceptor type emitter with an optimized nearly planar geometry
Authors: Chen Jia-Xiong , Xiao Ya-Fang , Wang Kai , Fan Xiao-Chun , Cao Chen , Chen Wen-Cheng , Zhang Xiang , Shi Yi-Zhong , Yu Jia , Geng Feng-Xia , Zhang Xiao-Hong , Lee Chun-Sing
Published: August 2020

Both PXZ-PPO with an optimized planar structure and PXZ-BOO with an optimized twisted structure exhibit TADF properties.
Identification of key gene modules and genes in colorectal cancer by co-expression analysis weighted gene co-expression network analysis
Authors: Wang Peng , Zheng Huaixin , Zhang Jiayu , Wang Yashu , Liu Pingping , Xuan Xiaoyan , Li Qianru , Du Ying
Published: August 2020

Colorectal cancer (CRC) has been one of the most common malignancies worldwide, which tends to get worse for the growth and aging of the population and westernized lifestyle. However, there is no effective treatment due to the complexity of its etiology. Hence, the pathogenic mechanisms remain to be clearly defined. In the present study, we adopted an advanced analytical method—Weighted Gene Co-expression Network Analysis (WGCNA) to identify the key gene modules and hub genes associated with CRC. In total, five gene co-expression modules were highly associated with CRC, of which, one gene module correlated with CRC significantly positive (R = 0.88). Functional enrichment analysis of genes in primary gene module found metabolic pathways, which might be a potentially important pathway involved in CRC. Further, we identified and verified some hub genes positively correlated with CRC by using Cytoscape software and UALCAN databases, including PAICS, ATR, AASDHPPT, DDX18, NUP107 and TOMM6. The present study discovered key gene modules and hub genes associated with CRC, which provide references to understand the pathogenesis of CRC and may be novel candidate target genes of CRC.
The Solar Orbiter magnetometer
Authors: Horbury T. S. , O’Brien H. , Carrasco Blazquez I. , Bendyk M. , Brown P. , Hudson R. , Evans V. , Oddy T. M. , Carr C. M. , Beek T. J. , Cupido E. , Bhattacharya S. , Dominguez J.-A. , Matthews L. , Myklebust V. R. , Whiteside B. , Bale S. D. , Baumjohann W. , Burgess D. , Carbone V. , Cargill P. , Eastwood J. , Erdös G. , Fletcher L. , Forsyth R. , Giacalone J. , Glassmeier K.-H. , Goldstein M. L. , Hoeksema T. , Lockwood M. , Magnes W. , Maksimovic M. , Marsch E. , Matthaeus W. H. , Murphy N. , Nakariakov V. M. , Owen C. J. , Owens M. , Rodriguez-Pacheco J. , Richter I. , Riley P. , Russell C. T. , Schwartz S. , Vainio R. , Velli M. , Vennerstrom S. , Walsh R. , Wimmer-Schweingruber R. F. , Zank G. , Müller D. , Zouganelis I. , Walsh A. P.
Published: August 2020

The magnetometer instrument on the Solar Orbiter mission is designed to measure the magnetic field local to the spacecraft continuously for the entire mission duration. The need to characterise not only the background magnetic field but also its variations on scales from far above to well below the proton gyroscale result in challenging requirements on stability, precision, and noise, as well as magnetic and operational limitations on both the spacecraft and other instruments. The challenging vibration and thermal environment has led to significant development of the mechanical sensor design. The overall instrument design, performance, data products, and operational strategy are described.
Detection capabilities of the Athena X-IFU for the warm-hot intergalactic medium using gamma-ray burst X-ray afterglows
Authors: Walsh Sarah , McBreen Sheila , Martin-Carrillo Antonio , Dauser Thomas , Wijers Nastasha , Wilms Jörn , Schaye Joop , Barret Didier
Published: August 2020

At low redshifts, the observed baryonic density falls far short of the total number of baryons predicted. Cosmological simulations suggest that these baryons reside in filamentary gas structures, known as the warm-hot intergalactic medium (WHIM). As a result of the high temperatures of these filaments, the matter is highly ionised such that it absorbs and emits far-UV and soft X-ray photons. Athena, the proposed European Space Agency X-ray observatory, aims to detect the “missing” baryons in the WHIM up to redshifts of z = 1 through absorption in active galactic nuclei and gamma-ray burst (GRB) afterglow spectra, allowing for the study of the evolution of these large-scale structures of the Universe. This work simulates WHIM filaments in the spectra of GRB X-ray afterglows with Athena using the SImulation of X-ray TElescopes framework. We investigate the feasibility of their detection with the X-IFU instrument, through O VII (E = 573 eV) and O VIII (E = 674 eV) absorption features, for a range of equivalent widths imprinted onto GRB afterglow spectra of observed starting fluxes ranging between 10−12 and 10−10 erg cm−2 s−1, in the 0.3−10 keV energy band. The analyses of X-IFU spectra by blind line search show that Athena will be able to detect O VII−O VIII absorption pairs with EWO VII > 0.13 eV and EWO VIII > 0.09 eV for afterglows with F > 2 × 10−11 erg cm−2 s−1. This allows for the detection of ≈ 45−137 O VII−O VIII absorbers during the four-year mission lifetime. The work shows that to obtain an O VII−O VIII detection of high statistical significance, the local hydrogen column density should be limited at NH < 8 × 1020 cm−2.
Supernovae Ib and Ic from the explosion of helium stars
Authors: Dessart Luc , Yoon Sung-Chul , Aguilera-Dena David R. , Langer Norbert
Published: August 2020

Much difficulty has so far prevented the emergence of a consistent scenario for the origin of Type Ib and Ic supernovae (SNe). Either the SN rates or the ejecta masses and composition were in tension with inferred properties from observations. Here, we follow a heuristic approach by examining the fate of helium stars in the mass range from 4 to 12 M⊙, which presumably form in interacting binaries. The helium stars were evolved using stellar wind mass loss rates that agree with observations and which reproduce the observed luminosity range of galactic Wolf-Rayet stars, leading to stellar masses at core collapse in the range from 3 to 5.5 M⊙. We then exploded these models adopting an explosion energy proportional to the ejecta mass, which is roughly consistent with theoretical predictions. We imposed a fixed 56Ni mass and strong mixing. The SN radiation from 3 to 100 d was computed self-consistently, starting from the input stellar models using the time-dependent nonlocal thermodynamic equilibrium radiative-transfer code CMFGEN. By design, our fiducial models yield very similar light curves, with a rise time of about 20 d and a peak luminosity of ~1042.2 erg s−1, which is in line with representative SNe Ibc. The less massive progenitors retain a He-rich envelope and reproduce the color, line widths, and line strengths of a representative sample of SNe Ib, while stellar winds remove most of the helium in the more massive progenitors, whose spectra match typical SNe Ic in detail. The transition between the predicted Ib-like and Ic-like spectra is continuous, but it is sharp, such that the resulting models essentially form a dichotomy. Further models computed with varying explosion energy, 56Ni mass, and long-term power injection from the remnant show that a moderate variation of these parameters can reproduce much of the diversity of SNe Ibc. We conclude that massive stars stripped by a binary companion can account for the vast majority of ordinary Type Ib and Ic SNe and that stellar wind mass loss is the key to removing the helium envelope in the progenitors of SNe Ic.
All good things come in threes: the third image of the lensed quasar PKS 1830−211
Authors: Muller S. , Jaswanth S. , Horellou C. , Martí-Vidal I.
Published: August 2020

Strong gravitational lensing distorts our view of sources at cosmological distances but brings invaluable constraints on the mass content of foreground objects and on the geometry and properties of the Universe. We report the detection of a third continuum source toward the strongly lensed quasar PKS 1830−211 in ALMA multi-frequency observations of high dynamic range and high angular resolution. This third source is point-like and located slightly to the north of the diagonal joining the two main lensed images, A and B, 0.3″ away from image B. It has a flux density that is ∼140 times weaker than images A and B and a similar spectral index, compatible with synchrotron emission. We conclude that this source is most likely the expected highly de-magnified third lensed image of the quasar. In addition, we detect, for the first time at millimeter wavelengths, weak and asymmetrical extensions departing from images A and B that correspond to the brightest regions of the Einstein ring seen at centimeter wavelengths. Their spectral index is steeper than that of compact images A, B, and C, which suggests that they arise from a different component of the quasar. Using the GravLens code, we explore the implications of our findings on the lensing model and propose a simple model that accurately reproduces our ALMA data and previous VLA observations. With a more precise and accurate measurement of the time delay between images A and B, the system PKS 1830−211 could help to constrain the Hubble constant to a precision of a few percent.
Étude du genre Campanile Fischer, 1884 (Mollusca : Gastropoda : Campanilidae). 1. Description d’une espèce nouvelle du Miocène supérieur du Cap Amparafaka (Madagascar)
Authors: Pacaud Jean-Michel
Published: August 2020

L’espèce Campanile madagasikara nov. sp. est décrite du Miocène supérieur du Cap Amparafaka à Madagascar. Le genre Campanile est signalé pour la première fois au Cénozoïque à Madagascar. En effet, le genre n’a pas jusqu’ici été rencontré à Madagascar, à part dans les sédiments crétacés. Il s’agit donc de l’occurrence la plus récente du genre jusqu’ici enregistré à Madagascar. Les Campanile au Miocène sont seulement présents en Asie du Sud-Est, en Nouvelle-Zélande, en Australie et en Afrique de l’Est. La découverte de l’espèce malgache décrite ici suggère l’existence d’aires relictes dans l’océan Indien et le Pacifique au Néogène et jusque dans l’actuel en Australie. L’identité des cordons spiraux est recherchée par leur correspondance topologique et ontogénétique, puis codifiée par une terminologie. Cette méthode descriptive utilisée par Pacaud J-M, Ledon D, Loubry P et Fernandez S. (2014. Importance de la correspondance ontogénétique et topologique de la sculpture spirale dans la discrimination des espèces du genre Campanile (Mollusca, Gastropoda). Fossiles, Revue française de paléontologie 19 : 23–49, fig. 1–17, pl. 1–12) permet de clarifier la présentation des caractères et de proposer des homologies structurales.
Structure, stability, and surface diffusion of clusters: Pt4/Cu (110) AND Au4/Ag (110) surface by molecular dynamics
Authors: Eddiai Fouad , Dardouri Moloudi , Hassani Abdessamad , Badawi Michael , Sbiaai Khalid , Hassnaoui Abdellatif
Published: August 2020

In this work, molecular dynamics simulations have been used to simulate the behavior of tetramer clusters behavior in Pt4/Cu (110) and Au4/Ag (110) systems, in the temperature range 300-600 K. All activation barriers and formation energies related to different tetramer shapes (4S, 4L, 4T, 4N and 4l) have been calculated by embedded atom method (EAM) at static regime (0 K). From an energetical point of view, the adatoms tend to diffuse via simple jumps and exchange mechanisms leading to a transition between all forms during tetramer diffusion. Statistical analysis after molecular dynamics simulations confirms that the linear 4l shape is more stable and needs high energy to be disintegrated in both systems. The lifetime study of each shape for different temperatures (from 300 K to 600 K) proves that the 4 l form is more stiff, which is in a good agreement with the formation energy predictions.
Enhanced efficiency thermo-optic phase-shifter by using multi-mode-interference device
Authors: Pant Bharat , Zhang Weiwei , Tran Denh , Banakar Mehdi , Du Han , Yan Xingzhao , Littlejohns Callum G. , Reed Graham T. , Thomson David J.
Published: August 2020

We demonstrate a method for power reduction in thermo-optic based Mach-Zehnder interferometer (MZI) by using the multimode region of a 2x2 Multi-Mode-Interferometer (MMI) as the modulation region. The light is circulated through the same multimode region twice and therefore utilizes the already present change in temperature leading to additional phase change, and an increase in efficiency. Power saving of 29.6% compared to a conventional thermo-optic phase shifter using single mode waveguides has been experimentally demonstrated. The reported devices show minimal insertion loss penalty compared to generic devices and do not add any additional fabrication complexity. Such an approach could also be applied to higher speed devices, for example those employing free carrier effects.
Symmetric spatio-temporal focusing of ultrashort pulses
Authors: Treffer A. , Kühn D. , Wyrowski F. , Grunwald R.
Published: August 2020

Simultaneous spatio-temporal focusing of few-cycle pulses is usually performed by stretcher-compressor configurations causing pulse-front tilt. By shaping and superimposing two reciprocal sub-beams, opposite tilts can compensate each other. Pulse propagation for asymmetric and symmetric focusing of near infrared 5-fs-pulses is studied by numerical simulations and proof-of-principle experiments.
Application of a pressure measuring film for pressure observation in overarm polishing
Authors: Benisch Michael F. , Faehnle Oliver , Rascher Rolf
Published: August 2020

In previous publications the inhomogeneous pressure transfer through the polishing tool onto a glass surface could be shown. This experiment shows polishing trials with different polishing materials and the differences in the homogeneity of the pressure transfer through them. Only the properties of the material will be discussed explicitly, the change of the tool constitution through the process will be part of further publications.
Fabrication and characterization of plasmonic band-stop filter using Ag grating
Authors: Motogaito Atsushi , Tanaka Ryoga , Hiramatsu Kazumasa
Published: August 2020

This study proposes a plasmonic band-stop filter with surface plasmon resonance in a doublelayer wire grid structure targeting short-wavelength visible and near-ultraviolet regions for applications in ultraviolet photography. Using Ag and Al, the rigorous coupling wave of analysis method revealed that the maximum absorption was approximately 90% at 450 nm and 375 nm. The experiments using Ag produced similar results in a simulation. These results demonstrate that plasmonic band-stop filters in the visible and near-UV region can be realized at 450 nm and 375 nm using Ag or Al.
Intensity dependent deflection spectroscopy for absorption measurements
Authors: Dickmann Walter , Götze Tom , Bieler Mark , Kroker Stefanie
Published: August 2020

We report on a method for the characterization of optical absorption in semiconductors at photon energies below the bandgap energy. We use intensity dependent deflection spectroscopy to measure spatially resolved the optical absorption and to separate the occurring absorption mechanisms. To this end, we take advantage of the different intensity scaling of these mechanisms and extract the material parameters by fitting the intensity dependent absorption to a physical model. Our method enables a simple but sufficient determination of crucial optical loss properties (e.g. impurity related absorption and two-photon absorption) in various semiconductor systems, e.g. substrates for optical components or solar cells.
Characterization progress of a UV-microscope recently implemented at the PTB Nanometer Comparator for uni- and bidirectional measurements
Authors: Krüger Jan , Köning Rainer , Bodermann Bernd
Published: August 2020

In this contribution, we emphasize the need for a sophisticated characterization of measurement devices in particular for optical bidirectional measurements. As an example, the ongoing characterization of the UV-microscope at PTB’s linescale comparator is presented. First results of spectroscopic measurements of the employed UV-LED are presented and the impact of deviations in the center wavelength of the LED on the measurements are illustrated by rigorous simulations.
Application of the Vernier method for absolute distance metrology with CW TOF phase shift technique
Authors: Gonçalves Nuno M. , Abreu Manuel , Castro Alves D.
Published: August 2020

A phase shift time of flight technique determines a position by comparing the phase angle of a continuously modulated signal in the source and its reflection on a target. However, due to its cyclical properties, the position information is contained within an ambiguity interval. For an absolute measurement, this interval is repeated N times plus a residual part given by the phase shift. In this work we propose an application of the Vernier method to determine N and a setup for mid-range applications (10-20) m with a 3 GHz amplitude modulated source to allow accuracies ≤ 100 μm.
Hybrid plasmonic/photonic crystals for optical detection of bacterial contaminants
Authors: Paternò Giuseppe M. , Moscardi Liliana , Donini Stefano , Ross Aaron M. , Pietralunga Silvia M. , Dalla Vedova Nicholas , Normani Simone , Kriegel Ilka , Lanzani Guglielmo , Scotognella Francesco
Published: August 2020

Here, we show that a hybrid plasmonic/photonic crystal consisting of a thin layer of bioactive plasmonic material (i.e. silver) deposited on top a 1D PhC can detect one of the most common bacterial contaminant, namely Escherichia coli. We speculate that the change in the plasmon charge density brought about by metal/bacterium interaction results in a variation of the plasmon resonance that, in turns, translates in a shift of the photonic structural color.
Revealing excited states dynamics in cross-linked covalent hybrids of graphene and diketopyrrolopyrrole oligomers via ultrafast transient absorption spectroscopy
Authors: Ross Aaron M. , Zheng Meng , Maggini Michele , Marangi Fabio , Cerullo Giulio , Gatti Teresa , Scotognella Francesco
Published: August 2020

We report on ultrafast dynamics in cross-linked covalent hybrids of graphene and diketopyrrolopyrrole (TDPP) oligomers. Comparisons between non-polymerizing (EXG-TDPP) and polymerizing (c-EXG-TDPP) hybrids show that charge/energy transfer occurs faster than 50 ps in EXGTDPP, while the c-EXG-TDPP system shows quenching within 18 ps. The transient response of c-EXGTDPP is completely quenched (>99%), while in EXG-TDPP full quenching occurs after 1.39 ns. Photocurrent studies of c-EXG-TDPP films show IPCE > 2%, indicating ultrafast charge transfer between TDPP and graphene.
Chalcogenide Optical Fiber Components -INVITED
Authors: Rochette Martin
Published: August 2020

This talk features recent achievements of the Nonlinear Photonics Group at McGill University towards the fabrication of chalcogenide-based optical fiber components such as nonlinear gain fibers, optical fiber couplers, filters, and saturable absorbers.
Optical scattering field imaging along a nanofiber in operando
Authors: Haddad Yosri , Chrétien Jacques , Margueron Samuel , Beugnot Jean-Charles , Fanjoux Gil
Published: August 2020

We present a non-destructive and non-invasive imaging spectroscopic technique with a high spatial and spectral resolution based on the detection of the Rayleigh scattering field radiated out of a centimetric length and micrometric size optical waveguide in operation.
Procedure to optimize the intercarrier spacing in superchannels impaired by the cascading of WSS-based ROADMs
Authors: Pereira Paulo J. , Rebola João L. , Cancela Luís G.
Published: August 2020

A new procedure is proposed to optimize the intercarrier spacing and wavelength selective switch (WSS) bandwidth for superchannels, using a Monte Carlo simulation. We perform an exhaustive assessment of the optical signal-to-noise ratio (OSNR) penalties due to the optical filtering and intercarrier crosstalk, and concluded that the optimum intercarrier spacing is at most 1.1 GHz larger than the Nyquist bandwidth and the results show how the number of cascaded WSSs influences the intercarrier spacing.
Multi-resonant optical parametric oscillator without mirrors based on 1D and 2D-PPLT nonlinear photonic crystal
Authors: Mohand Ousaid Safia , Chakaroun Mahmoud , Chang Kai-hsun , Billeton Thierry , Peng L-Han , Boudrioua Azzedine
Published: August 2020

In this work, we demonstrate that it is possible to obtain an optical parametric oscillator with a simultaneous amplification of multiple frequencies using only a nonlinear photonic crystal with highly polished end-faces, preventing the utilization of external cavity mirrors.
Visible short-pulses generation by nonlinear propagation of necklace beams in capillaries
Authors: Crego Aurora , San Roman Julio , Conejero Jarque Enrique
Published: August 2020

We study numerically the propagation of necklace beams through a gas-filled capillary. Ultra-short pulses in the visible (VIS) region can be obtained due to the spectral broadening of these necklace beams. This new source of few-cycle VIS pulses can be generated carrying tens of microjoules of energy using these special beams, being a valuable tool for the improvement of the standard post-compression schemes in terms of spatial stability and output energy.
Photonic generation of picosecond pulse doublets from the nonlinear splitting of super-Gaussian pulses
Authors: Finot Christophe
Published: August 2020

We experimentally demonstrate the generation of temporal pulse doublets from the propagation of initial super-Gaussian waveforms in an optical fiber with anomalous dispersion. The nonlinear focusing dynamics leads to picosecond structures that are characterized both in amplitude and phase. Their close-to-Gaussian Fourier-transform limited shape is found in excellent agreement with numerical simulations. This single-stage reshaping scheme is energy efficient, can sustain GHz repetition rates and temporal compression factors around 10 are demonstrated.
Transient Dynamical-Thermal-Optical System Modeling and Simulation
Authors: Hahn Luzia , Eberhard Peter
Published: August 2020

In this work, methods and procedures are investigated for the holistic simulation of the dynamicalthermal behavior of high-performance optics like lithography objectives. Flexible multibody systems in combination with model order reduction methods, finite element thermal analysis and optical system analyses are used for transient simulations of the dynamical-thermal behavior of optical systems at low computational cost.
Integration of Arrayed Waveguide Grating on Strip-Loaded Slot Waveguide for Sensing Applications
Authors: Tippinit Janvit , Kuittinen Markku , Roussey Matthieu
Published: August 2020

We demonstrate the integration of arrayed waveguide grating (AWG) de-multiplexer with a low loss and low index contrast platform, i.e., a striped-loaded slot waveguide (SLWG). The SLSW-AWG is designed to operate around the wavelength λ = 1550 nm with a four-output channel. The device experiences excellent output parameters: channel width δλ = 1.39 nm at -3dB, channel spacing Δλ = 2.43 nm and extinction ratio ER = 9.87 dB, useful for sensing applications.
Correlation between polychromatic image quality metrics to predict visual acuity in pseudophakic patients
Authors: Armengol Jesús , Garzón Nuria , Vega Fidel , Altemir Irene , Millán María S.
Published: August 2020

The optical quality of three multifocal intraocular lenses (MIOLs) was measured in vitro using the area under the modulation transfer function (MTFa) and energy efficiency (EE). We evaluated those metrics through-focus (TF) by axially scanning the image space with three wavelengths (R, G, B). High linear correlation between MTFa and EE was found for all cases. Correlations between optical in vitro results (polychromatic TF-MTFa and TF-EE) and clinical visual acuity (VA) defocus curves for the three MIOLs allowed us to derive mathematical expressions. Both metrics proved to be equivalent to predict postoperative VA.
Optimizing the CMOS Sensor-Mode for Extreme Linear Dynamic Range MEMS-based CAOS Smart Camera Imaging
Authors: Riza Nabeel A. , Ashraf Nazim , Mazhar Mohsin
Published: August 2020

Experimentally highlighted are the limitations & optimizations of the CMOS sensor-mode engaged for the CAOS smart camera. Demonstrated is an optimized method for finding the Camera Response Function (CRF) using a calibrated target.
Three-dimensional laser writing inside silicon using THz-repetition-rate trains of ultrashort pulses
Authors: Wang Andong , Das Amlan , Grojo David
Published: August 2020

Three-dimensional laser writing inside silicon remains today inaccessible with the shortest infrared light pulses unless complex schemes are used to circumvent screening propagation nonlinearities. Here, we explore a new approach irradiating silicon with trains of femtosecond laser pulses at repetition rates up to 5.6 THz. This extremely high repetition rate is faster than laser energy dissipation from microvolume inside silicon, thus enabling unique capabilities for pulse-to-pulse accumulation of free carriers generated by nonlinear ionization, as well as progressive thermal bandgap closure before any diffusion process comes into play. By space-resolved measurements of energy delivery inside silicon, we evidence a net increase on the level of space-time energy localization. The improvement is also supported by experiments demonstrating an apparent decrease of the energy threshold for modification and drastic improvements on the repeatability, uniformity, and symmetricity of the produced features. The unique benefits of THz bursts can provide a new route to meet the challenge of 3D inscription inside narrow bandgap materials.