bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxicology of tramadol following chronic exposure based on metabolomics of the cerebrum in mice
Authors: Xia Wei , Liu Guojie , Shao Ziyi , Xu Enyu , Yuan Huiya , Liu Junting , Gao Lina
Published: July 2020

Tramadol is an opioid used as an analgesic for treating moderate or severe pain. The long-term use of tramadol can induce several adverse effects. The toxicological mechanism of tramadol abuse is unclear. Metabolomics is a very useful method for investigating the toxicology of drug abuse. We investigated the impact of chronic tramadol administration on the cerebrum of mice, focusing on the metabolites after tramadol administration. The mice received 20 or 50 mg/kg body weight tramadol dissolved in physiological saline daily for 5 weeks via oral gavage. Compared with the control group, the low dose tramadol group showed seven potential biomarkers, including gamma-hydroxybutyric acid, succinate semialdehyde, and methylmalonic acid, which were either up- or down-regulated. Compared with the control group, the high dose tramadol group showed ten potential biomarkers, including gamma-hydroxybutyric acid, glutamine, and O-phosphorylethanolamine, which were either up- or down-regulated. The up-regulated gamma-hydroxybutyric acid and the down-regulated succinate semialdehyde revealed that the neurotransmitter system was disrupted after tramadol abuse. Compared with the low dose tramadol group, there were twenty-nine potential biomarkers in the high dose tramadol group, mainly related to the pentose phosphate pathway and glycerophospholipid metabolism. In conclusion, metabolomics in the tramadol abuse group demonstrated that long-term tramadol abuse can result in oxidative damage, inflammation, and disruption of the GABA neurotransmitter system, which will help to elucidate the toxicology of tramadol abuse.
Optimization of process parameters for preparation of polystyrene PM2.5 particles by supercritical antisolvent method using BBD-RSM
Authors: Zhang Zhuo , Li Qingling , Guo Bo , Zhang Shouzhong , Zhang Sen , Hu Dedong
Published: July 2020

The objective of this study is to optimize the process parameters for preparing polystyrene (PS) PM2.5 particles by supercritical antisolvent (SAS) method. Toluene was selected as the solvent and supercritical carbon dioxide (SC-CO2) was used as the antisolvent. The Box–Behnken design-response surface method was applied to investigate the effect of crystallizer pressure, PS massic concentration, flow ratio of CO2/solution and crystallizer temperature on the size and the distribution of PS particles, systematically. It is found that crystallizer temperature is the most significant variable on the size and the distribution of PS particles, followed by flow ratio of CO2/solution and PS massic concentration, and crystallizer pressure is the slightest significant factor. The particle size increases with the increase of crystallizer temperature. The optimum conditions are obtained as crystallizer pressure 9.8 MPa, PS massic concentration 1.6 wt%, flow ratio of CO2/solution 140 g/g and crystallizer temperature 309 K. Under these conditions, the PS particle with the size of 2.78 μm and a narrow size distribution has been prepared, meeting PM2.5 standard aerosols. The results suggest that it is feasible to produce PM2.5 standard aerosols by SAS.
Tactile perception of pleasantness in relation to perceived softness
Authors: Pasqualotto Achille , Ng Megan , Tan Zheng Yee , Kitada Ryo
Published: July 2020

The sense of touch allows us to infer objects’ physical properties, while the same input also produces affective sensations. These affective sensations are important for interpersonal relationships and personal well-being, which raises the possibility that tactile preferences are adapted to the characteristics of the skin. Previous studies examined how physical properties such as surface roughness and temperature influence affective sensations; however, little is known about the effect of compliance (physical correlate of softness) on pleasantness. Thus, we investigated the psychophysical link between softness and pleasantness. Pieces of human skin-like rubber with different compliances were pressed against participants’ fingers. Two groups of participants numerically estimated the perceived magnitude of either pleasantness or softness. The perceived magnitude of pleasantness and softness both increased monotonically as a function of increasing object compliance, levelling off at around the end of the stimulus range. However, inter-subject variability was greater for pleasantness than for perceived softness, whereas the slope of the linear function fit to the magnitude estimates was steeper for softness than for pleasantness. These results indicate that object compliance is a critical physical determinant for pleasantness, whereas the effect of compliance on pleasantness was more variable among individuals than the effect on softness was.
Toxicity of fluralaner, a companion animal insecticide, relative to industry-leading agricultural insecticides against resistant and susceptible strains of filth flies
Authors: Burgess Edwin R. , Geden Christopher J. , Lohmeyer Kimberly H. , King B. H. , Machtinger Erika T. , Scott Jeffrey G.
Published: July 2020

Filth flies cause billions of dollars of losses annually to the animal production industry. Fluralaner is a relatively new pesticide currently sold for control of fleas, ticks, and mites on companion animals and poultry. We examined the efficacy of fluralaner against three species of filth flies. Insecticide-susceptible horn flies and stable flies were tested topically. Fluralaner outperformed permethrin by > 2-fold for the horn flies but underperformed permethrin by > 45-fold for stable flies at 24 h. House flies were tested topically with fluralaner in comparison to permethrin at 48 h and orally with fluralaner in comparison to imidacloprid at 24 h. Topical fluralaner was 6- to 28-fold as toxic as permethrin in four pyrethroid-resistant strains and not significantly less toxic than permethrin in a susceptible strain and a mildly pyrethroid-resistant strain. There was slight cross-resistance between topically applied fluralaner and permethrin in all five insecticide-resistant strains tested. Oral fluralaner was more toxic than imidacloprid in all four house fly strains tested, 9- to 118-fold as toxic. Oral cross-resistance between imidacloprid and fluralaner was not detected, but imidacloprid resistance was not high in any of the tested strains. Fluralaner shows promise for control of horn flies and house flies.
Publisher Correction: Feasibility and effects of enhanced recovery vs. conventional care after emergency colon surgery for patients with left colon perforation
Authors: Viñas X. , Macarulla E. , Brugiotti C. , Ramirez J. M. , Pedregosa A. , Sanchez S. , Camps J. , Arroyo A.
Published: July 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Loop currents in two-leg ladder cuprates
Authors: Bounoua Dalila , Mangin-Thro Lucile , Jeong Jaehong , Saint-Martin Romuald , Pinsard-Gaudart Loreynne , Sidis Yvan , Bourges Philippe
Published: July 2020

New phases with broken discrete Ising symmetries are uncovered in quantum materials with strong electronic correlations. The two-leg ladder cuprate Sr14−xCaxCu24O41 hosts a very rich phase diagram where, upon hole doping, the system exhibits a spin liquid state ending to an intriguing ordered magnetic state at larger Ca content. Using polarized neutron diffraction, we report here the existence of short range magnetism in this material for two Ca contents, whose origin cannot be ascribed to Cu spins. This magnetism develops exclusively within the two-leg ladders with a diffraction pattern at forbidden Bragg scattering, which is the hallmark of loop current-like magnetism breaking both time-reversal and parity symmetries. Our discovery shows local discrete symmetry breaking in a one dimensional spin liquid system as theoretically predicted. It further suggests that a loop current-like phase could trigger the long range magnetic order reported at larger doping in two-leg ladder cuprates.
Gel Phantoms for MRI Quality Assurance and Testing
Authors: De Deene Y.
Published: July 2020

In the development of new MRI pulse sequences and in setting up quantitative diagnostic protocols, benchmarking against a golden standard is a logical step. Several quality assurance (QA) phantoms have been developed. QA phantoms provided by scanner manufacturers mostly contain an aqueous solution, but may be susceptible to motion artefacts that originate from convection currents which do not occur in vivo. Gel phantoms do not exhibit these motion artefacts. Several research groups have developed phantoms that are tuned to specific MRI applications, such as for geometrical precision measurements in stereotactic surgery, T1, T2 and MT mapping, in vivo NMR spectroscopy, magnetic susceptibility mapping, flow measurements, BOLD, and multi-modality imaging. Gel phantoms are also very useful in testing MRI compatibility and safety of medical implants.
Melittin-encapsulating peptide hydrogels for enhanced delivery of impermeable anticancer peptides
Authors: Feng Jue-Ping , Zhu Ru , Jiang Fagang , Xie Jie , Gao Chang , Li Min , Jin Honglin , Fu Dehao
Published: July 2020

Anticancer peptides (ACPs) have gained significant attention in the past few years.
Detection and time-tracking activation of a photosensitiser on live single colorectal cancer cells using Raman spectroscopy
Authors: Gala de Pablo Julia , Chisholm David R. , Ambler Carrie A. , Peyman Sally A. , Whiting Andrew , Evans Stephen D.
Published: July 2020

Tracking of the accumulation, activation, degradation of a photosensitiser and cell response in live colorectal cancer single-cells using Raman spectroscopy.
Real-world evaluation of a novel technology for quantitative simultaneous antibody detection against multiple SARS-CoV-2 antigens in a cohort of patients presenting with COVID-19 syndrome
Authors: Shaw Andrew M. , Hyde Christopher , Merrick Blair , James-Pemberton Philip , Squires Bethany K. , Olkhov Rouslan V. , Batra Rahul , Patel Amita , Bisnauthsing Karen , Nebbia Gaia , MacMahon Eithne , Douthwaite Sam , Malim Michael , Neil Stuart , Martinez Nunez Rocio , Doores Katie , Mark Tan Kia Ik , Signell Adrian W. , Betancor Gilberto , Wilson Harry D. , Galão Rui Pedro , Pickering Suzanne , Edgeworth Jonathan D.
Published: July 2020

An evaluation of a rapid portable gold-nanotechnology measuring SARS-CoV-2 IgM, IgA and IgG antibody response to spike 1 (S1), spike 2 (S) and nucleocapsid (N) antigens using serum from 74 RNA(+) patients and RNA(+) 47 control patients.
A new alternative assay for sensitive analysis of ethylenethiourea and propylenethiourea in fruit samples after their separation
Authors: Nantaphol Siriwan , Moonla Chochanon , Promvichai Siriwipa , Tangkuaram Tanin , Chailapakul Orawon , Siangproh Weena
Published: July 2020

A new assay for sensitive analysis of ethylenethiourea and propylenethiourea in fruit samples.
Investigating the interaction between three perfluorinated carboxylic acids and the G protein-coupled estrogen receptor: spectroscopic analyses and computational simulations
Authors: Yong Li , Huang Manting , Wei Yuchen , Xu Jie , Yi Zhongsheng
Published: July 2020

Here, perfluorobutyric acid (PFBA), perfluorooctanoic acid (PFOA) and perfluorododecanoic acid (PFDoA) were selected as typical representatives of perfluorinated carboxylic acids (PFCAs) to study the effects of PFCAs on the G protein-coupled estrogen receptor (GPER).
Design, synthesis and characterization of structurally dynamic cyclic N,S-acetals
Authors: Kirkeby Emily K. , Roberts Andrew G.
Published: July 2020

We report the synthesis, characterization and comparison of a series of electronically perturbed, cyclic N,S-acetals.
Ligand-enabled gold-catalyzed 1,2-heteroarylation of alkenes
Authors: Tathe Akash G. , Chintawar Chetan C. , Bhoyare Vivek W. , Patil Nitin T.
Published: July 2020

By adopting the interplay between ligand-enabled Au(i)/Au(iii) catalysis and the unique π-activation mode of gold complexes, a highly coveted 1,2-heteroarylation of alkenes has been accomplished.
First exfoliated Ru–Ru–Au organometallic polymer with layered structure
Authors: Scalambra Franco , Sierra-Martin Benjamin , Serrano-Ruiz Manuel , Fernandez-Barbero Antonio , Romerosa Antonio
Published: July 2020

A novel Ru–Ru–Au 3D heterometallic polymer self-assembles in single layers with large scale hexagonal conformation, as well as forming 3D stacks of polymer sandwiches.
Single-atom metal-modified graphenylene as a high-activity catalyst for CO and NO oxidation
Authors: Tang Yanan , Chen Weiguang , Zhang Hongwei , Wang Zhiwen , Teng Da , Cui Yingqi , Feng Zhen , Dai Xianqi
Published: July 2020

Herein, the adsorption behaviors and interactions of different gas species on single-metal atom-anchored graphenylene (M–graphenylene, M = Mn, Co, Ni, and Cu) sheets were investigated by first-principles calculations.
Photoluminescence spectral broadening, chirality transfer and amplification of chiral perovskite materials (R-X-p-mBZA)2PbBr4 (X = H, F, Cl, Br) regulated by van der Waals and halogen atoms interactions
Authors: Zhou Chenyang , Chu Ya , Ma Linlin , Zhong Yingqian , Wang Chao , Liu Yalan , Zhang Haoyue , Wang Beibei , Feng Xia , Yu Xi , Zhang Xiaotao , Sun Yan , Li Xiaozeng , Zhao Guangjiu
Published: July 2020

We introduced halogen-substituted chiral molecules as A-site cations to synthesize a series of novel organic–inorganic hybrid 2D chiral perovskite materials (R-X-p-mBZA)2PbBr4 (X = H, F, Cl, Br; p: para-position; mBZA = α-methylbenzylamine).
Cancer stem cell-targeted bio-imaging and chemotherapeutic perspective
Authors: Han Jiyou , Won Miae , Kim Ji Hyeon , Jung Eugeine , Min Kyungim , Jangili Paramesh , Kim Jong Seung
Published: July 2020

Characteristics of CSCs targeted for developing therapeutic and bio-imaging agents.
An innovative magnetic Ni0.1Co0.9Fe2O4/g-C3N4 nano-micro-spherical heterojunction composite photocatalyst with an extraordinarily prominent visible-light-irradiation degradation performance toward organic pollutants
Authors: Ying Zongrong , Sun Jing , Lin Xuemei , Wang Yuxuan , Hui Shengjie , Zhang Yongzheng
Published: July 2020

An ultra-high-performance magnetic heterojunction photocatalyst was fabricated via post co-calcining the mixture of solvothermal micro-spherical g-C3N4 and nanospherical Ni0.1Co0.9Fe2O4.
Uniaxial thermal expansion behaviors and ionic conduction in a layered (NH4)2V3O8
Authors: Yao Zhi-Yuan , Zhang Guo-Qin , Yao Wan-Wan , Wang Xiao-Zu , Qian Yin , Ren Xiao-Ming
Published: July 2020

Layered (NH4)2V3O8 exhibits ZTE and NTE behaviors along the c-axis, and ZTE nature along the a-axis owing to swing-like movement of vanadyl in VO4 tetrahedra and transverse vibration of bridged O atoms connecting VO4 tetrahedra.
Hydrogenation/dehydrogenation of N-heterocycles catalyzed by ruthenium complexes based on multimodal proton-responsive CNN(H) pincer ligands
Authors: Sánchez Práxedes , Hernández-Juárez Martín , Rendón Nuria , López-Serrano Joaquín , Santos Laura L. , Álvarez Eleuterio , Paneque Margarita , Suárez Andrés
Published: July 2020

Ru-CNN(H) complexes are efficient precatalysts in the hydrogenation and dehydrogenation of N-heterocycles. Under basic conditions, these derivatives lead to the formation of Ru(0) species that are observed under catalytic conditions.
Bcl-xL inhibits tBid and Bax via distinct mechanisms
Authors: Murad Fabronia , Garcia-Saez Ana J.
Published: July 2020

Quantification of interactions and localization dynamics of Bcl-xL with tBid and Bax reveals differences in the mechanism of inhibition.
Natural deep eutectic solvent mediated extrusion for continuous high-solid pretreatment of lignocellulosic biomass
Authors: Ai Binling , Li Wenqi , Woomer Joseph , Li Mi , Pu Yunqiao , Sheng Zhanwu , Zheng Lili , Adedeji Akinbode , Ragauskas Arthur J. , Shi Jian
Published: July 2020

Continuous high-solid pretreatment of lignocellulosic biomass using natural deep eutectic solvent mediated extrusion.
PDI-based heteroacenes as acceptors for fullerene-free solar cells: importance of their twisted geometry
Authors: Chen Huaqing , Wang Ling , Sun Hua , Liu Qian , Tan Xiao , Sang Shenglong , Wu Bo , Zhang Cong , Chen Fei , Hang Xiao-Chun , Chen Zhi-Kuan
Published: July 2020

Two novel PDI-based small molecules with twisted geometry were designed and synthesised as acceptors for organic solar cells.
Study on the fluorescence properties of micron-submicron-nano BaFBr:Eu2+ phosphors
Authors: Chen Long , Wu Yang , Huo Heyong , Tang Bin , Fu Yuhua , Hu Xiujie , Sun Chenghua , Zhou Shuyun
Published: July 2020

BaFBr:Eu2+ with narrow size distribution and good dispersion is fabricated via a precipitation method. After annealing, it shows excellent optical properties.
One-step fabrication of photoluminescent SiC quantum dots through a radiation technique
Authors: Qi Wei , Li Mengjie , Zhao Long
Published: July 2020

The fabrication of PL SiC-QDs by using ionic liquid-based microemulsions combined with electron beam radiation.
Long-armed hexapod nanocrystals of cesium lead bromide
Authors: Li Shangkun , Probst Julie , Howes Philip D. , deMello Andrew J.
Published: July 2020

Cesium lead bromide nanosheets undergo a slow transformation from nanosheets to long-armed hexapods, revealing the utility of extended incubation times in perovskite nanocrystal shape control.
High-mobility In and Ga co-doped ZnO nanowires for high-performance transistors and ultraviolet photodetectors
Authors: Li Fangzhou , Meng You , Kang Xiaolin , Yip SenPo , Bu Xiuming , Zhang Heng , Ho Johnny C.
Published: July 2020

In and Ga co-doping does not only enhance the carrier concentration but also suppresses the formation of oxygen vacancy defects within ZnO nanowires, enabling high-performance transistors and ultraviolet photodetectors.
Long-lasting ultraviolet-A persistent luminescence and photostimulated persistent luminescence in Bi3+-doped LiScGeO4phosphor
Authors: Zhang Yi , Chen Dongxun , Wang Weili , Yan Shao , Liu Jingwei , Liang Yanjie
Published: July 2020

A UVA emissive LiScGeO4:Bi3+persistent phosphor is developed, which exhibits single-band, long-lasting persistent luminescence and a photostimulated persistent luminescence capability.
Degradation pathway and microbial mechanism of high-concentration thiocyanate in gold mine tailings wastewater
Authors: Li Lei , Yue Fanyao , Li Yancheng , Yang Aijiang , Li Jiang , Lv Yang , Zhong Xiong
Published: July 2020

Thiocyanate (SCN−) was degraded in COS pathway, and the removal rate was 99.94%. The Thiobacillus played an important role.
Sulfadiazine hosted in MIL-53(Al) as a biocide topical delivery system
Authors: Águila-Rosas Javier , Quirino-Barreda Tomás , Leyva-Gómez Gerardo , González-Zamora Eduardo , Ibarra Ilich A. , Lima Enrique
Published: July 2020

Sulfadiazine (SDZ), a bacteriostatic agent, was hosted in MIL-53(Al) and modified-zinc MIL-53(Al,Zn).
Thermo-driven self-assembly of a PEG-containing amphiphile in a bilayer membrane
Authors: Li Rui , Muraoka Takahiro , Kinbara Kazushi
Published: July 2020

A synthetic multi-block amphiphile containing oligoethylene glycol chains formed a self-assembly in a bilayer membrane triggered by thermal stimuli.
Van der Waals heterostructures of SiC and Janus MSSe (M = Mo, W) monolayers: a first principles study
Authors: Idrees M. , Fawad M. , Bilal M. , Saeed Y. , Nguyen C. , Amin Bin
Published: July 2020

Using DFT calculations, we have investigated the electronic structure, Rashba effect, optical and photocatalytic performance of SiC-MSSe (M = Mo, W) van der Waals heterostructures with different stacking patterns of chalcogen atoms.
Magnetic phase transition from paramagnetic in Nb2AlC-MAX to superconductivity-like diamagnetic in Nb2C-MXene: an experimental and computational analysis
Authors: Din Babar Zaheer Ud , Fatheema Jameela , Arif Nimrah , Anwar M. S. , Gul Sundus , Iqbal Mudassir , Rizwan Syed
Published: July 2020

Transition metal carbides (TMCs) have recently emerged as competent members among the family of two-dimensional (2D) materials, owing to their promising applications.
Shift, rotation and scale invariant optical fingerprint verification system with double random phase encoding
Authors: Zhuo Shengkai , Jiao Shuming , Zou Wenbin , Wang Na , Li Xia
Published: July 2020

Biometric features such as fingerprint images can be authenticated by not only computer algorithms but also optical systems. In previous works, double random phase encoding (DRPE) optical lens system is employed for fingerprint verification. However, such a system can yield authentication failure when the key is generated from a slightly distorted fingerprint image. In this work, a fingerprint image pre‐processing scheme for DRPE fingerprint optical authentication system is proposed. Simulated experimental results demonstrate the proposed method has significantly better robustness to shift, rotation and scale variance than some of the conventional DRPE‐based approaches.
Recurrent spatial transformer network for high‐accuracy image registration in moving PCB defect detection
Authors: Huang Weibo , Hua Guoliang , Yu Zhaofu , Liu Hong
Published: July 2020

Defects detection is an extremely important part in the production of printed circuit board (PCB) to guarantee the quality and reliability. A widely used and researched method for this task is referential comparison method. However, this method gets poor performance on the situation that PCB moves on the conveyor, due to the lack of ability to register test images with referential images. Therefore, accurate image registration which estimates the affine transformation between the captured test images and the referential images becomes an urgent problem to be solved. In this study, a spatial transformer network is proposed. In particular, a recurrent image registration strategy is introduced to step‐by‐step register the images in a recurrent progress. Furthermore, a referential part is designed to help training the network. Besides, in order to simulate the real moving PCB images and train the proposed model, a factitious dataset is generated by applying random affine transformations to real PCB images. Experiments show that recurrent spatial transformer network can achieve pixel‐level accurate image registration. The defects detection precision of referential comparison method has a great improvement by using the registration algorithm.
Observer‐based iterative learning control for linear time‐varying systems using LMI
Authors: Li Ben‐Qi , Wang Yi‐Ming , Feng Li , Chai Yi
Published: July 2020

This study presents the design of an observer‐based iterative learning control law for linear systems using the stability theory and optimal function. The observer is introduced for states condition monitoring and output feedback. The D‐type iterative learning control law is utilised to update the control inputs. Properties of stability, convergence, robustness, and optimality are investigated and demonstrated by stability theory and optimal theory. The convergence properties of the observer‐based iterative learning control design are obtained by linear matrix inequalities. A simulation example is used to illustrate the validity and effectiveness of the proposed method.
A self-consistent method for the simulation of meteor trails with an application to radio observations
Authors: Bariselli F. , Boccelli S. , Dias B. , Hubin A. , Magin T. E.
Published: July 2020

Context.Radio-based techniques allow for a meteor detection of 24 h. Electromagnetic waves are scattered by the electrons produced by the ablated species colliding with the incoming air. As the electrons dissipate in the trail, the received signal decays. The interpretation of these measurements entails complex physical modelling of the flow.

Aims.In this work, we present a procedure to compute extensive meteor trails in the rarefied segment of the trajectory. This procedure is a general and standalone methodology, which provides meteor physical parameters at given trajectory conditions, without the need to rely on phenomenological lumped models.

Methods.We started from fully kinetic simulations of the evaporated gas that describe the nonequilibrium in the flow and the ionisation collisions experienced by metals in their encounter with air molecules. These simulations were employed as initial conditions for performing detailed chemical and multicomponent diffusion calculations of the extended trail, in order to study the processes which lead to the extinction of the plasma. In particular, we focused on the evolution of the trail generated by a 1 mm meteoroid flying at 32 km s−1, above 80 km. We retrieved the ambipolar diffusion coefficient and the electron line density and compared the outcome of our computations with classical results and observational fittings. Finally, the electron field was employed to estimate the resulting reflected signal, using classical radio-echo theory for underdense meteors.

Results.A global and constant diffusion coefficient is sufficient to reproduce numerical profiles. A good agreement is found when we compare the extracted diffusion coefficients with theory and observations.
Dense gas in a giant molecular filament
Authors: Wang Y. , Beuther H. , Schneider N. , Meidt S. E. , Linz H. , Ragan S. , Zucker C. , Battersby C. , Soler J. D. , Schinnerer E. , Bigiel F. , Colombo D. , Henning Th.
Published: July 2020

Context. Recent surveys of the Galactic plane in the dust continuum and CO emission lines reveal that large (≳50 pc) and massive (≳105 M⊙) filaments, know as giant molecular filaments (GMFs), may be linked to Galactic dynamics and trace the mid-plane of the gravitational potential in the Milky Way. Yet our physical understanding of GMFs is still poor.

Aims. We investigate the dense gas properties of one GMF, with the ultimate goal of connecting these dense gas tracers with star formation processes in the GMF.

Methods. We imaged one entire GMF located at l ~ 52–54° longitude, GMF54 (~68 pc long), in the empirical dense gas tracers using the HCN(1–0), HNC(1–0), and HCO+(1–0) lines, and their 13C isotopologue transitions, as well as the N2H+(1–0) line. We studied the dense gas distribution, the column density probability density functions (N-PDFs), and the line ratios within the GMF.

Results. The dense gas molecular transitions follow the extended structure of the filament with area filling factors between 0.06 and 0.28 with respect to 13CO(1–0). We constructed the N-PDFs of H2 for each of the dense gas tracers based on their column densities and assumed uniform abundance. The N-PDFs of the dense gas tracers appear curved in log–log representation, and the HCO+ N-PDF has the flattest power-law slope index. Studying the N-PDFs for sub-regions of GMF54, we found an evolutionary trend in the N-PDFs that high-mass star-forming and photon-dominated regions have flatter power-law indices. The integrated intensity ratios of the molecular lines in GMF54 are comparable to those in nearby galaxies. In particular, the N2H+/13CO ratio, which traces the dense gas fraction, has similar values in GMF54 and all nearby galaxies except Ultraluminous Infrared Galaxies.

Conclusions. As the largest coherent cold gaseous structure in our Milky Way, GMFs, are outstanding candidates for connecting studies of star formation on Galactic and extragalactic scales. By analyzing a complete map of the dense gas in a GMF we have found that: (1) the dense gas N-PDFs appear flatter in more evolved regions and steeper in younger regions, and (2) its integrated dense gas intensity ratios are similar to those of nearby galaxies.
Atmospheric parameters of Cepheids from flux ratios with ATHOS
Authors: Lemasle Bertrand , Hanke Michael , Storm Jesper , Bono Giuseppe , Grebel Eva K.
Published: July 2020

Context. The effective temperature is a key parameter governing the properties of a star. For stellar chemistry, it has the strongest impact on the accuracy of the abundances derived. Since Cepheids are pulsating stars, determining their effective temperature is more complicated than in the case of nonvariable stars.

Aims. We want to provide a new temperature scale for classical Cepheids, with a high precision and full control of the systematics.

Methods. Using a data-driven machine learning technique employing observed spectra, and in taking great care to accurately phase single-epoch observations, we tied flux ratios to (label) temperatures derived using the infrared surface brightness method.

Results. We identified 143 flux ratios, which allow us to determine the effective temperature with a precision of a few Kelvin and an accuracy better than 150 K, which is in line with the most accurate temperature measures available to date. The method does not require a normalization of the input spectra and provides homogeneous temperatures for low- and high-resolution spectra, even at the lowest signal-to-noise ratios. Due to the lack of a dataset with a sufficient sample size for Small Magellanic Cloud Cepheids, the temperature scale does not extend to Cepheids with [Fe/H] < −0.6 dex. However, it nevertheless provides an exquisite, homogeneous means of characterizing Galactic and Large Magellanic Cloud Cepheids.

Conclusions. The temperature scale will be extremely useful in the context of spectroscopic surveys for Milky Way archaeology with the WEAVE and 4MOST spectrographs. It paves the way for highly accurate and precise metallicity estimates, which will allow us to assess the possible metallicity dependence of Cepheids’ period-luminosity relations and, in turn, to improve our measurement of the Hubble constant H0.
A Comparison of Surface Slopes Extracted from ICESat Waveform Data and High Resolution DEM
Authors: Xie Huan , Tang Hong , Du Wenjia , Tong Xiaohua
Published: July 2020

Surface slope is an important topographic variable, accurate surface slope can support many research appliacations. Large footprint full waveform data has been used to estimate the surface slope and performes well. In this paper, surface slope within laser footprint is calculated using the Ice, Cloud, and land Elevation Satellite (ICESat) Geoscience Laser Altimeter System (GLAS) full waveform data and a high resolution Digital Elevation Model (REMA, the Reference Elevation Model of Antarctica). A comparison is done between two extracted surface slopes, the results show that the slopes extracted from full waveform data are close to slopes extracted from DEM, and the width of waveform can be used to extract surface slope in moderately sloping surface.
Development of ATLID Retrieval Algorithms
Authors: Donovan D.P. , van Zadelhoff G-J , Williams J. E. , Wandinger U. , Haarig M. , Qu Z.
Published: July 2020

ATLID (“ATmospheric LIDar”) is the lidar to be flown on the multi-instrument Earth Clouds and Radiation Explorer (EarthCARE or ECARE) joint ESA/JAXA mission now scheduled for launch in 2022. ATID is a 3 channel linearly polarized High-Spectral Resolution (HSRL) system operating at 355nm. Cloud and aerosol optical properties are key ECARE products. This paper will provide an overview of the ATLID L2a (i.e. single instrument) retrieval algorithms being developed and implemented in order to derive cloud and aerosol optical properties.
Dual-Wavelength High-Spectral-Resolution Lidar for Profiling Optical Properties of Aerosol and Cloud
Authors: Shen Xue , Wang Nanchao , Liu Dong , Xiao Da , Rong Yuhang , Zhong Tianfen , Liu Chong , Zhang Yupeng , Zhou Yudi , Chen Sijie
Published: July 2020

A dual-wavelength high-spectral-resolution lidar (HSRL) based on an iodine absorption filter and a field-widened Michelson interferometer (FWMI) has been developed to profile backscatter and extinction coefficients of aerosols and clouds accurately. This instrument was tested and calibrated on multiple observations in Hangzhou and Zhoushan, respectively, from August 2018 to April 2019. This paper discusses the design and the internal calibration method of the lidar system in detail, with several typical cases of observations and the analysis of these data products. The optical properties of urban aerosols in Hangzhou and the evolvement of clouds in Zhoushan are presented, respectively.
Identification of Aerosol Sources in Siberia and Study of Aerosol Transport at Regional Scale by Airborne and Space-Borne Lidar Measurement
Authors: Zabukovec Antonin , Ancellet Gérard , Pelon Jacques , Paris J.D. , Penner Iogannes E. , Kokhanenko Grigorii , Balin Yuri S.
Published: July 2020

Airborne lidar measurements were carried out over Siberia in July 2013 and June 2017. Aerosol optical properties are derived using the Lagrangian FLEXible PARTicle dispersion model (FLEXPART) simulations and Moderate Resolution Imaging Spectrometer (MODIS) AOD. Comparison with Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol products is used to validate the CALIOP aerosol type identification above Siberia. Two case studies are discussed : a mixture of dust and pollution from Northern Kazakhstan and smoke plumes from forest fires. Comparisons with the CALIOP backscatter ratio show that CALIOP algorithm may overestimate the LR for a dusty mixture if not constrained by an independent AOD measurement.
Preprocessing of Raman Lidar Signal Over a High Altitude Station in India: Practical Considerations
Authors: Jaswant  , Singh Shishir Kumar , Radhakrishnan S.R. , Shukla Devesh , Sharma Chhemendra
Published: July 2020

Lidar can provide the range-resolved information about the vertical profiles of optical properties of aerosol content and clouds present in the atmosphere. However, before obtaining the information from received lidar signal we ought to use a few pre-processing techniques such as range-correction, temporal and spatial averaging, dead time correction of the photon counts (PC) signal, correction due to overlap effect, Simulation of molecular Rayleigh signal and gluing analog & PC signals. In this work, we have discussed some of the initial pre-processing techniques ought to be performed before lidar inversion.
Profiling Aerosol Optical Properties at the Central Asian Site of Dushanbe, Tajikistan: Pure Dust Cases
Authors: Hofer Julian , Althausen Dietrich , Abdullaev Sabur F. , Makhmudov Abduvosit N. , Nazarov Bakhron I. , Baars Holger , Engelmann Ronny , Ansmann Albert
Published: July 2020

Tajikistan is often affected by atmospheric mineral dust originating from various surrounding deserts. The direct and indirect radiative effects of that dust play a sensitive role in the Central Asian climate system and therefore need to be quantified. The Central Asian Dust Experiment (CADEX) provides for the first time an aerosol climatology for Central Asia based long-term aerosol profiling by ground-based lidar (PollyXT type) in Dushanbe, Tajikistan. For pure dust cases, mean depolarization(lidar) ratios of 0.23±0.03(44±3 sr) at 355 nm and 0.32±0.02(38±3 sr) at 532 nm wavelength have been measured. The mean extinction-related Ångström exponent was 0.18±0.15.
Set of Algorithms and Techniques for Accurate 3D, Single Beam – Single Pointing, Lidar Measurements for Slant Range Visibility, Planetary Boundary Layer Height and Wind Speed Retrieval, Atmospheric Layers Spatial Distribution and Categorization in Real Time
Authors: Pantazis Alexandros , Papayannis Alexandros
Published: July 2020

In this work, a full set of recently developed algorithms and techniques is presented, for a single beam-single pointing lidar to be able to perform operational and independent accurate 3 Dimensional (3D) measurements, for slant range visibility, wind speed retrieval, atmospheric layers spatial distribution and categorization, as well as Planetary Boundary Layer Height (PBLH) retrieval, in real or Near Real Time (NRT).The idea behind this development was for any single lidar to be able to perform a set of accurately measured products, either mobile or stationary, with or without network connectivity with other sensors for data-information exchange. The products were determined by the needs of lidar remote scientific and commercial community, in order to be even more attractive and valuable to atmospheric scientists, meteorologists, aviation and shipping safety operators, as well as to the Space lidar community.
CH4 and CO2 IPDA Lidar Measurements During the Comet 2018 Airborne Field Campaign
Authors: Fix Andreas , Amediek Axel , Büdenbender Christian , Ehret Gerhard , Kiemle Christoph , Quatrevalet Mathieu , Wirth Martin , Wolff Sebastian , Bovensmann Heinrich , Butz André , Gałkowski Michał , Gerbig Christoph , Jöckel Patrick , Marshall Julia , Nęcki Jarosław , Pfeilsticker Klaus , Roiger Anke , Swolkień Justyna , Zöger Martin ,   the CoMet team
Published: July 2020

Installed onboard the German research aircraft HALO, the integrated-path differential-absorption (IPDA) lidar CHARM-F measures weighted vertical columns of both greenhouse gases (GHG) below the aircraft and along its flight track, aiming at high accuracy and precision. Results will be shown from the deployment during the CoMet field campaign that was carried out in spring 2018, with its main focus on one of the major European hot spots in methane emissions: the Upper Silesian Coal Basin (USCB) in Poland. First analyses reveal a measurement precision of below 0.5% for 20-km averages and also low bias, which was assessed by comparison with in-situ instruments. The measurements flights were designed to capture individual CH4 and CO2 plumes from e.g. coal mine venting and coal-fired power plants, respectively, but also to measure large and regional scale GHG gradients and to provide comparisons with the Total Carbon Column Observing Network (TCCON). Many other different instruments, both airborne and ground-based, complemented the lidar measurements to provide a comprehensive dataset for model analyses. CHARM-F also acts as the airborne demonstrator for MERLIN, the “Methane Remote Lidar Mission”, conducted by the German and French space agencies, DLR and CNES, with launch foreseen in ~ 2024. In this context, the airborne lidar data are likewise important for mission support such as for e.g. algorithm development and improvement and, moreover, the CoMet mission was also an important step for MERLIN validation preparation.
Comparison Among the Atmospheric Boundary Layer Height Estimated From Three Different Tracers
Authors: de Arruda Moreira Gregori , da Silva Lopes Fábio Juliano , Guerrero-Rascado Juan Luis , Ortiz-Amezcua Pablo , Cazorla Alberto , de Oliveira Amauri Pereira , Landulfo Eduardo , Alados-Arboledas Lucas
Published: July 2020

The Atmospheric Boundary Layer (ABL) is the lowermost part of the troposphere. In this work, we analysed the combination of ABL height estimated continuously by three different remote sensing systems: a ceilometer, a Doppler lidar and a passive Microwave Radiometer, during a summer campaign, which was held in Granada from June to August 2016. This study demonstrates as the combined utilization of remote sensing systems, based on different tracers, can provide detailed information about the height of ABL and their sublayers.
Lidar Observation of Mesospheric Clouds Above Beijing: A Case Study
Authors: Gong Shaohua , Yang Guotao , Wang Jihong , Xun Yuchang , Wu Foju , Li Qinzeng , Liu Xiao , Chen Chunxia , Tian Dawei
Published: July 2020

We report on the first observation of mesospheric cloud (MC) at the altitude range of 50-65 km with lidars at Yanqing (40.5°N, 116°E) and Pingquan (41°N, 118.7°E) on 30 October 2018. The MC occurred at the 51-56 km altitude range during the hours of dawn. It had an obvious double-layer structure, but the cloud layer was sparse. The MC was re-observed at the 56-62 km altitude range in the twilight, and the double-layer structure was still obvious. However, the cloud layer became thicker with a maximum volume backscatter coefficient (BSC) 3.1×10−10m−1sr−1. Atmospheric temperature structure was derived according to the lidar observations, and it was found that, several hours before the MC occurrence, a temperature anomaly with coldest temperature ~185 K was propagating downward at the altitudes of 50-65 km. This MC layer was simultaneously observed with lidar at Pingquan in the twilight. It could be a regional MC event and possibly formed locally by a transient cooling due to small-scale disturbances in the mesosphere.
ACTRIS and its Aerosol Remote Sensing Component
Authors: Wandinger Ulla , Nicolae Doina , Pappalardo Gelsomina , Mona Lucia , Comerón Adolfo
Published: July 2020

The Aerosol, Clouds and Trace Gases Research Infrastructure ACTRIS is currently being developed with support from more than 20 countries and more than 100 research-performing organizations in Europe. The pan-European distributed research infrastructure shall provide data and services related to short-lived atmospheric constituents to facilitate high-quality Earth system research in the long term (over at least 20 years). While some of the activities are already in place, ACTRIS functionality will be further ramped up until full operation in 2025. The observation of aerosol, clouds and reactive trace gases with in-situ and remote-sensing techniques in ACTRIS is supported by six Topical Centres, which are responsible for common standards and quality assurance. Free and open virtual access to ACTRIS data is provided by the Data Centre. International users will also have physical access to ACTRIS observatories, atmospheric simulation chambers and mobile platforms as well as remote or physical access to calibration services, digital services and training. Access provision is organized through a single-entry point by the Head Office. In this contribution, the general principles and structure of ACTRIS are introduced, and the observational component related to aerosol remote sensing, which builds on the heritage of the European Aerosol Research Lidar Network (EARLINET) and the European part of the Aerosol Robotic Network (AERONET-Europe), is explained in more detail.
Water Vapour and Temperature Measurements by Raman Lidar in the Frame of the NDACC
Authors: De Rosa Benedetto , Di Girolamo Paolo , Summa Donato
Published: July 2020

In November 2012, the University of BASILicata Raman Lidar system (BASIL) was approved to enter the International Network for the Detection of Atmospheric Composition Change (NDACC). Since then measurements were routinely carried out on a once per week basis. This paper illustrates specific measurement examples from this effort, with a dedicated focus on temperature and water vapour measurements, with the ultimate goal to provide a characterization of the system performance. Case studies illustrated in this paper demonstrate the ability of BASIL to perform measurements of the temperature profile up to 50 km and of the water vapour mixing ratio profile up to 15 km, based on an integration time of 2 hours and a vertical resolution of 150 m, with measurement bias not exceeding 0.1 K and 0.1 g kg−1, respectively. Raman lidar measurements are compared with measurements from additional instruments, such as radiosondings and satellite sensors (IASI and AIRS), and with model re-analyses data (ECMWF and ECMWF-ERA). Comparisons in this paper cover the altitude interval up to 15 km for water vapour mixing ratio and up to 50 km for the temperature. Comparisons between BASIL and the different sensor/model data in terms of water vapour mixing ratio indicate a mean absolute/relative bias of -0.024 g kg−1(or -3.9 %), 0.342 g kg−1(or 36.8 %), 0.346 g kg−1 (or 37.5 %), -0.297 g kg−1 (or -25 %), -0.381 g kg−1 (or -31 %), when compared with radisondings, AIRS, IASI, ECMWF, ECMWF-ERA, respectively. For what concerns the comparisons in terms of temperature measurements, these indicate a mean absolute bias between BASIL and the radisondings, AIRS, IASI, ECMWF, ECMWF-ERA of -0.04, 1.99, 0.48, 0.14, 0.62 K, respectively. Based on the available dataset and benefiting from the circumstance that the Raman lidar BASIL could be compared with all other sensor/model data, it has been possible to estimate the absolute bias of all sensors/datasets, this being 0.004 g kg−1/0.30 K, 0.021 g kg−1/-0.34 K, -0.35 g kg−1/0.18 K, -0.346 g kg−1/-1.63 K, 0.293 g kg−1/-0.16 K and 0.377 g kg−1/0.32 K in terms of water vapour mixing ratio/temperature for BASIL, the radisondings, IASI, AIRS, ECMWF, ECMWF-ERA, respectively.
BeCOOL: A Balloon-Borne Microlidar System Designed for Cirrus and Convective Overshoot Monitoring
Authors: Ravetta François , Mariage Vincent , Brousse Emmanuel , d’Almeida Eric , Ferreira Frédéric , Pelon Jacques , Victori Stéphane
Published: July 2020

A balloon-borne microlidar has been built at LATMOS to monitor cirrus optical properties and convective overshoot topography during long duration flights in the lower tropical stratosphere. Weighting less than 7 kg in a reduced volume and consuming less than 10 W, it will be involved in the CNES-Strateole2 campaign. This instrument paves the way to the use of microlidar technology for planetary missions.
Design and Development of a Raman Lidar for Cherenkov Gamma Array Experiments
Authors: Vasileiadis George , Brun Patrick , Gabella Omar , Rivoire Stephane , Avdikos George , Louridas Alexandros , Georgoussis George , Papayannis Alexandros
Published: July 2020

Future Cherenkov Gamma Ray (CGR) experiments will reach a sensitivity and energy resolution never obtained until now by any other high energy gamma–ray experiment. It is well known that atmospheric conditions contribute particularly in this aspect. Raman lidars can help reduce the systematic uncertainties of the molecular and aerosol components of the atmosphere so these performances can be reached. The motivation for Raman lidars and the design and development of the Montpellier Raman lidar system is described. It provides both multiple elastic and Raman readout channels and custom-made optics design. Preliminary lidar tests and signals show the actual performance of the lidar in consistency with the desired goals.
Drone-Based Fluorescence Lidar Systems for Vegetation and Marine Environment Monitoring
Authors: Duan Zheng , Li Ying , Wang Xun , Wang Jinlei , Brydegaard Mikkel , Zhao Guangyu , Svanberg Sune
Published: July 2020

We have developed two different types of drone-based fluorescence lidar systems for vegetation and marine environment monitoring, both based on violet CW diode lasers. An inelastic hyperspectral Scheimpflug lidar system was used for vegetation profiling combined with fluorescence spectral recordings. A light-weight fluorosensor set for fixed-height recordings was employed for monitoring of marine environments, featuring water Raman signals, algal chlorophyll and strong oil spill fluorescence.
Lidar Innovations for Technologies and Environmental Sciences (LITES) – An Remote Sensing Infrastructure Facility: Setup and Measurements Examples
Authors: Tatarov Boyan , Müller Detlef , Tesche Matthias , Shin Sung-Kyun
Published: July 2020

At the University of Hertfordshire, we have been developing a new remote sensing facility (LITES) to explore the feasibility of using Raman and/or fluorescence backscattering for chemical aerosol profiling. This paper provides an overview of the instruments of the facility and measurement examples. LITES includes a ultra-high-energy Nd:YAG/OPO setup, spectroscopic equipment with high spectral resolution, several imaging and single detectors that allow for time-resolved (lidar) signal detection, a Raman/fluorescence microscope, and a suite of gas and aerosol chambers. We present examples of elastic, rotational and vibrational spectroscopic lidar signals, as well as in-situ microscopic spectrums of dust and bio-aerosol compounds.