bluuebunny/crossref_metadata_2025 huggingface dataset:
Viscosity of Pyroxenite Melt and Its Evolution During Cooling
Authors: Vetere F. , Murri M. , Alvaro M. , Domeneghetti M. C. , Rossi S. , Pisello A. , Perugini D. , Holtz F.
Published: May 2019

New viscosity experiments at superliquidus temperatures and during cooling at a rate of 10 K/hr have been performed at different shear rates on a synthetic pyroxenite melt. Results revealed that this melt is extremely fluid at temperature between 1646 and 1530 K and measured viscosities are between 2.2 and 7.8 Pa·s. Such very low viscosities allow the lava to flow in turbulent regime as confirmed by the high Reynolds numbers, which are always >2,000. As a consequence, very long distance could be covered by the lava flow. If we consider this studied composition as proxy for Mars lava flows coupled with very high effusion rates, our results might explain the presence of extraordinary large volcanic channels, as recently hypothesized for the Kasei Valles on Mars, even considering that the gravity is approximately one third that of Earth. Few literature data tracking viscosity during cooling are available, and they reported shear thinning effect on different compositions. Our experiments performed at 0.1 and 1 s−1 have shown complex variation in the apparent viscosity, confirming that nonequilibrium rheology represents a still unexplored field of investigation useful to better understand the real geological scenarios occurring in magmatic and volcanic systems.
PEAT‐CLSM: A Specific Treatment of Peatland Hydrology in the NASA Catchment Land Surface Model
Authors: Bechtold M. , De Lannoy G. J. M. , Koster R. D. , Reichle R. H. , Mahanama S. P. , Bleuten W. , Bourgault M. A. , Brümmer C. , Burdun I. , Desai A. R. , Devito K. , Grünwald T. , Grygoruk M. , Humphreys E. R. , Klatt J. , Kurbatova J. , Lohila A. , Munir T. M. , Nilsson M. B. , Price J. S. , Röhl M. , Schneider A. , Tiemeyer B.
Published: May 2019

Peatlands are poorly represented in global Earth system modeling frameworks. Here we add a peatland‐specific land surface hydrology module (PEAT‐CLSM) to the Catchment Land Surface Model (CLSM) of the NASA Goddard Earth Observing System (GEOS) framework. The amended TOPMODEL approach of the original CLSM that uses topography characteristics to model catchment processes is discarded, and a peatland‐specific model concept is realized in its place. To facilitate its utilization in operational GEOS efforts, PEAT‐CLSM uses the basic structure of CLSM and the same global input data. Parameters used in PEAT‐CLSM are based on literature data. A suite of CLSM and PEAT‐CLSM simulations for peatland areas between 40°N and 75°N is presented and evaluated against a newly compiled data set of groundwater table depth and eddy covariance observations of latent and sensible heat fluxes in natural and seminatural peatlands. CLSM's simulated groundwater tables are too deep and variable, whereas PEAT‐CLSM simulates a mean groundwater table depth of −0.20 m (snow‐free unfrozen period) with moderate temporal fluctuations (standard deviation of 0.10 m), in significantly better agreement with in situ observations. Relative to an operational CLSM version that simply includes peat as a soil class, the temporal correlation coefficient is increased on average by 0.16 and reaches 0.64 for bogs and 0.66 for fens when driven with global atmospheric forcing data. In PEAT‐CLSM, runoff is increased on average by 38% and evapotranspiration is reduced by 19%. The evapotranspiration reduction constitutes a significant improvement relative to eddy covariance measurements.
Opportunity Rover Mission Complete
Authors: Cartier Kimberly
Published: May 2019

The rover explored Mars’s surface for nearly 15 years and discovered ample evidence of the planet’s wet history.
RNA sequencing identifies clonal structure of T-cell repertoires in patients with adult T-cell leukemia/lymphoma
Authors: Farmanbar Amir , Kneller Robert , Firouzi Sanaz
Published: May 2019

The diversity of T-cell receptor (TCR) repertoires, as generated by somatic DNA rearrangements, is central to immune system function. High-throughput sequencing technologies now allow examination of antigen receptor repertoires at single-nucleotide and, more recently, single-cell resolution. The TCR repertoire can be altered in the context of infections, malignancies or immunological disorders. Here we examined the diversity of TCR clonality and its association with pathogenesis and prognosis in adult T-cell leukemia/lymphoma (ATL), a malignancy caused by infection with human T-cell leukemia virus type-1 (HTLV-1). We analyzed 62 sets of high-throughput RNA sequencing data from 59 samples of HTLV-1−infected individuals—asymptomatic carriers (ACs), smoldering, chronic, acute and lymphoma ATL subtypes—and three uninfected controls to evaluate TCR distribution. Based on these TCR profiles, CD4-positive cells and ACs showed polyclonal patterns, whereas ATL patients showed oligo- or monoclonal patterns (with 446 average clonotypes across samples). Expression of TCRα and TCRβ genes in the dominant clone differed among the samples. ACs, CD4-positive samples and smoldering patients showed significantly higher TCR diversity compared with chronic, acute and lymphoma subtypes. CDR3 sequence length distribution, amino acid conservation and gene usage variability for ATL patients resembled those of peripheral blood cells from ACs and healthy donors. Thus, determining monoclonal architecture and clonal diversity by RNA sequencing might be useful for prognostic purposes and for personalizing ATL diagnosis and assessment of treatments.
Dissecting R gene and host genetic background effect on the Brassica napus defense response to Leptosphaeria maculans
Authors: Haddadi Parham , Larkan Nicholas J. , Borhan M. Hossein
Published: May 2019

While our understanding of the genetics underlying the Brassica-Leptosphaeria pathosystem has advanced greatly in the last decade, differences in molecular responses due to interaction between resistance genes and host genetic background has not been studied. We applied RNAseq technology to monitor the transcriptome profiles of Brassica napus (Bn) lines carrying one of four blackleg R genes (Rlm2, Rlm3, LepR1 & LepR2) in Topas or Westar background, during the early stages of infection by a Leptosphaeria maculans (Lm) isolate carrying the corresponding Avr genes. We observed upregulation of host genes involved in hormone signalling, cell wall thickening, response to chitin and glucosinolate production in all R gene lines at 3 day after inoculation (dai) albeit having higher level of expression in LepR1 and Rlm2 than in Rlm3 and LepR2 lines. Bn-SOBIR1 (Suppressor Of BIR1-1), a receptor like kinase (RLK) that forms complex receptor like proteins (RLPs) was highly expressed in LepR1 and Rlm2 at 3 dai. In contrast Bn-SOBIR1 induction was low in Rlm3 line, which could indicate that Rlm3 may function independent of SOBIR1. Expression of Salicylic acid (SA) related defense was enhanced in LepR1 and Rlm2 at 3 dai. In contrast to SA, expression of Bn genes with homology to PDF1.2, a jasmonic acid (JA) pathway marker, were increased in all Rlm and LepR lines at 6 and 9 dai. Effect of host genetic background on induction of defense, was determined by comparison of LepR1 and LepR2 in Topas vs Westar genotype (i.e. T-LepR1 vs W-LepR1 and T-LepR2 vs W-LepR2). In both cases (regardless of R gene) overall number of defense related genes at the earliest time point (3 dai) was higher in Tops compared to Westar. SA and JA markers genes such as PR1 and PDF1.2 were more induced in Topas compared to Westar introgression lines at this time point. Even in the absence of any R gene, effect of Topas genotype in enhanced defense, was also evident by the induction of PDF1.2 that started at a low level at 3 dai and peaked at 6 and 9 dai, while no induction in Westar genotype was observed at any of these time points. Overall, variation in time and intensity of expression of genes related to defense, was clearly dependent on both R gene and the host genotype.
Ultra-high sensitive 1D porous silicon photonic crystal sensor based on the coupling of Tamm/Fano resonances in the mid-infrared region
Authors: Ahmed Ashour M. , Mehaney Ahmed
Published: May 2019

Porous silicon one-dimensional photonic crystals (PSi-1DPCs) are capable of sensing solutions and liquids based on the smallest variation of the refractive indices. In the present work, we present a novel metal/PSi-1DPC as a liquid sensor based on Tamm/Fano resonances. The operating wavelength range is from 6.35 to 9.85 μm in the mid-infrared (MIR) spectral region. Different metals (Al, Ag, Au, and Pt) are attached to the top surface of the PSi-1DPCs structure to show Tamm/Fano resonances more clearly. To the best of our knowledge, it is the first time that Tamm/Fano resonances exhibit simultaneously in PSi-1DPCs within the same structure. The reflection spectra were calculated for the metal/PSi-1DPC structure by using the transfer matrix method (TMM) and the Bruggeman’s effective medium approximation (BEMA). The simulations show that the Tamm/Fano resonances are red-shifted towards the higher wavelengths with increasing the refractive index of the pores. The Ag/PSi-1DPC sensor showed the highest performance. Its sensitivity can be reached to the value 5018 nm/RIU with a high-quality factor of about 2149.27. We predict the proposed sensors can be easily fabricated and we expect them to show higher performance than other reported sensors of this type. Therefore, it will be of interest in the field of optical sensing in different fields.
Sugar accumulation and growth of lettuce exposed to different lighting modes of red and blue LED light
Authors: Chen Xiao-li , Wang Li-chun , Li Tao , Yang Qi-chang , Guo Wen-zhong
Published: May 2019

The present study evaluated the growth response and sugar accumulation of lettuce exposed to different lighting modes of red and blue LED light based on the same daily light integral (7.49 μmol·m−2). Six lighting treatments were performed, that were monochromatic red light (R), monochromatic blue light (B), simultaneous red and blue light as the control (RB, R:B = 1:1), mixed modes of R, B and RB (R/RB/B, 4 h R to 4 h RB and then 4 h B), and alternating red and blue light with alternating intervals of 4 h and 1 h respectively recorded as R/B(4 h) and R/B(1 h). The Results showed that different irradiation modes led to obvious morphological changes in lettuce. Among all the treatments, the highest fresh and dry weight of lettuce shoot were both detected with R/B(1 h), significantly higher than the other treatments. Compared with plants treated with RB, the contents of fructose, glucose, crude fiber as well as the total sweetness index (TSI) of lettuce were significantly enhanced by R treatment; meanwhile, monochromatic R significantly promoted the activities of sucrose degrading enzymes such as acid invertase (AI) and neutral invertase (NI), while obviously reduced the activity of sucrose synthesizing enzyme (SPS). Additionally. The highest contents of sucrose and starch accompanied with the strongest activity of SPS were detected in plants treated with R/B(1 h). The alternating treatments R/B(4 h) and R/B(1 h) inhibited the activity of SS, while enhanced that of SPS compared with the other treatments, indicating that different light environment might influence sugar compositions via regulating the activities of sucrose metabolism enzymes. On the whole, R/B(1 h) was the optimal lighting strategy in terms of lettuce yield, taste and energy use efficiency in the present study.
RNAi mediated myosuppressin deficiency affects muscle development and survival in the salmon louse (Lepeophtheirus salmonis)
Authors: Komisarczuk Anna Z. , Kongshaug Heidi , Li Ming , Nilsen Frank
Published: May 2019

Muscle activity is regulated by stimulatory and inhibitory neuropeptides allowing for contraction and relaxation. In Arthropods, one of the important myoinhibitors is Myosuppressin, belonging to FMRFamide-like peptides, that was shown to have inhibitory effects on visceral muscle contraction and to regulate vital physiological processes including reproduction or feeding. We have identified myosuppressin in salmon louse Lepeophtheirus salmonis (LsalMS) and systematically characterised its function and complex abnormalities emerging after LsalMS knockdown by RNAi in all developmental stages in this species. Immunohistochemistry analysis localized the LsalMS mainly to the central nervous system, but also to the vital organs within the alimentary tract and the reproductive system. The most striking feature of LsalMS deficiency during lice development was severe reduction of the muscle content, with abnormalities detected in both the visceral and skeletal muscles. Moreover, down-regulation of LsalMS affects moulting, spermatophore deposition and feeding by affecting development of the intestinal wall and increasing its contraction frequency.
Quantile regression analysis reveals widespread evidence for gene-environment or gene-gene interactions in myopia development
Authors: Pozarickij Alfred , Williams Cathy , Hysi Pirro G. , Guggenheim Jeremy A. ,   UK Biobank Eye and Vision Consortium, Aslam Tariq , Barman Sarah A. , Barrett Jenny H. , Bishop Paul , Blows Peter , Bunce Catey , Carare Roxana O. , Chakravarthy Usha , Chan Michelle , Chua Sharon Y.L. , Crabb David P. , Cumberland Philippa M. , Day Alexander , Desai Parul , Dhillon Bal , Dick Andrew D. , Egan Cathy , Ennis Sarah , Foster Paul , Fruttiger Marcus , Gallacher John E.J. , Garway-Heath David F. , Gibson Jane , Gore Dan , Hammond Chris J. , Hardcastle Alison , Harding Simon P. , Hogg Ruth E. , Keane Pearse A. , Khaw Sir Peng T. , Khawaja Anthony P. , Lascaratos Gerassimos , Lotery Andrew J. , Mac Gillivray Tom , Mackie Sarah , Martin Keith , McGaughey Michelle , McGuinness Bernadette , McKay Gareth J. , McKibbin Martin , Mitry Danny , Moore Tony , Morgan James E. , Muthy Zaynah A. , O’Sullivan Eoin , Owen Chris G. , Patel Praveen , Paterson Euan , Peto Tunde , Petzold Axel , Rahi Jugnoo S. , Rudnikca Alicja R. , Self Jay , Sivaprasad Sobha , Steel David , Stratton Irene , Strouthidis Nicholas , Sudlow Cathie , Thomas Dhanes , Trucco Emanuele , Tufail Adnan , Vitart Veronique , Vernon Stephen A. , Viswanathan Ananth C. , Williams Katie , Woodside Jayne V. , Yates Max M. , Yip Jennifer , Zheng Yalin
Published: May 2019

A genetic contribution to refractive error has been confirmed by the discovery of more than 150 associated variants in genome-wide association studies (GWAS). Environmental factors such as education and time outdoors also demonstrate strong associations. Currently however, the extent of gene-environment or gene-gene interactions in myopia is unknown. We tested the hypothesis that refractive error-associated variants exhibit effect size heterogeneity, a hallmark feature of genetic interactions. Of 146 variants tested, evidence of non-uniform, non-linear effects were observed for 66 (45%) at Bonferroni-corrected significance (P < 1.1 × 10−4) and 128 (88%) at nominal significance (P < 0.05). LAMA2 variant rs12193446, for example, had an effect size varying from −0.20 diopters (95% CI −0.18 to −0.23) to −0.89 diopters (95% CI −0.71 to −1.07) in different individuals. SNP effects were strongest at the phenotype extremes and weaker in emmetropes. A parsimonious explanation for these findings is that gene-environment or gene-gene interactions in myopia are pervasive.
Influence of boron doping on the dynamics of formation of Os metal nanoclusters on graphitic surfaces
Authors: Pitto-Barry Anaïs , Barry Nicolas P. E.
Published: May 2019

Unprecedented metal–boron interactions within nanomaterials and insights into the role of doping heteroatoms in nucleation processes are reported herein.
Multi-mass velocity-map imaging studies of photoinduced and electron-induced chemistry
Authors: Vallance Claire
Published: May 2019

Multimass velocity-map imaging promises new mechanistic insights into chemistry relevant to fields ranging from atmospheric chemistry and astrochemistry through to synthetic organic photochemistry and biology.
Spectroscopic identification of quinacridone polymorphs for organic electronics
Authors: Salzillo Tommaso , Rivalta Arianna , Castagnetti Nicola , D'Agostino Simone , Masino Matteo , Grepioni Fabrizia , Venuti Elisabetta , Brillante Aldo , Girlando Alberto
Published: May 2019

The combination of different nondestructive spectroscopic techniques (Raman, infrared, luminescence) is shown to provide identification of quinacridone polymorphs when this well known pigment is used in organic electronics devices.
The dynamic evaporation process of the deep eutectic solvent LiTf2N:N-methylacetamide at ambient temperature
Authors: Chen Yu , Yu Dongkun , Fu Li , Wang Meng , Feng Dongran , Yang Yingze , Xue Xiaomeng , Wang Jinfang , Mu Tiancheng
Published: May 2019

The dynamic evaporation process of the lithium-based deep eutectic solvent LiTf2N:NMA under ambient conditions can be divided into three stages.
Two-dimensional supramolecular crystal engineering: chirality manipulation
Authors: Huan Jinwen , Zhang Xuemei , Zeng Qingdao
Published: May 2019

This review summarizes the recent progress in chirality manipulation on 2D supramolecular crystal engineering.
Coexistence of structurally similar but electronically distinct isomers of delocalized cation radicals as a basis for the development of functional materials
Authors: Talipov Marat R. , Steiner Esther
Published: May 2019

Certain low-symmetry aromatic molecules with a small HOMO/HOMO−1 energy gap might co-exist as electronic isomers in their cation radical states that differ only in bond lengths yet have distinct optical and electronic properties.
Anion (O, N, C, and S) vacancies promoted photocatalytic nitrogen fixation
Authors: Mao Chengliang , Wang Jiaxian , Zou Yunjie , Li Hao , Zhan Guangming , Li Jie , Zhao Jincai , Zhang Lizhi
Published: May 2019

Mild-condition nitrogen fixation using “green” solar energy, merely requiring a solar-to-NH3 (STA) efficiency of 0.1% for potential use, is a promising alternative to the Haber–Bosch process but remains a great challenge.
Trap passivation and efficiency improvement of perovskite solar cells by a guanidinium additive
Authors: Yao Jiaxu , Wang Hui , Wang Pang , Gurney Robert S. , Intaniwet Akarin , Ruankham Pipat , Choopun Supab , Liu Dan , Wang Tao
Published: May 2019

Incorporation of an effective additive 1,3-diaminoguanidine monohydrochloride in MAPbI3 film can increase the grain size and reduce trap density, consequently increasing the carrier lifetime and reducing charge recombination, leading to an improved efficiency from 19.1% to 20.3% in a p–i–n structured solar cell.
Investigation of novel nanomaterial for the removal of toxic substances from contaminated water
Authors: El-Sayed Wessam N. , Elwakeel Khalid Z. , Shahat Ahmed , Awual Md. Rabiul
Published: May 2019

Preparation of novel nanosphere material for efficient capture of toxic substances. The nanosphere material was systematically investigated for the capture of a toxic substance. The material displayed high sensitivity with high adsorption efficiency.
Tailoring of the electronic property of Zn-BTC metal–organic framework via ligand functionalization: an ab initio investigation
Authors: Degaga Gemechis D. , Pandey Ravindra , Gupta Chansi , Bharadwaj Lalit
Published: May 2019

The structure–property relationships of pristine and functionalized Zn-BTC (Zn3(BTC)2) metal–organic frameworks are investigated.
Anionic nanoparticle-lipid membrane interactions: the protonation of anionic ligands at the membrane surface reduces membrane disruption
Authors: Salassi Sebastian , Canepa Ester , Ferrando Riccardo , Rossi Giulia
Published: May 2019

The interaction between anionic Au nanoparticles and model lipid membranes is facilitated by the spontaneous protonation of the NP ligand carboxylate groups, COO−˙ → COOH, in the lipid headgroup region.
Tube-rolling and formation of mechanically robust micro-tubes in graphene oxide aqueous dispersions during shear flow
Authors: Ok Chang Min , Kim Seo Gyun , Jeong Seung Yol , Lee Heon Sang
Published: May 2019

Mechanically robust GO micro-tubes are formed spontaneously when GO aqueous dispersions flow slowly in a confined geometry at low pH values.
Synthesis and characterization of a hierarchically structured three-dimensional conducting scaffold for highly stable Li metal anodes
Authors: Kim Ji Young , Liu Guicheng , Tran Minh Xuan , Anugrah Ardhi Ryanda Enggar , Kim Hansung , Lee Joong Kee
Published: May 2019

This unique hierarchically structured 3D conducting scaffold could significantly improve the stability of Li metal anodes.
Engineering quorum quenching enzymes: progress and perspectives
Authors: Murugayah Shereen A. , Gerth Monica L.
Published: May 2019

Quorum sensing is a key contributor to the virulence of many important plant, animal and human pathogens. The disruption of this signalling—a process referred to as ‘quorum quenching’—is a promising new approach for controlling microbial pathogens. In this mini-review, we have focused on efforts to engineer enzymes that disrupt quorum sensing by inactivating acyl-homoserine lactone signalling molecules. We review different approaches for protein engineering and provide examples of how these engineering approaches have been used to tailor the stability, specificity and activities of quorum quenching enzymes. Finally, we grapple with some of the issues around these approaches—including the disconnect between in vitro biochemistry and potential in vivo applications.
Efficacy of Intratympanic Steroid on Idiopathic Sudden Sensorineural Hearing Loss: An Analysis of Cases With Negative Prognostic Factors
Authors: Suzuki Hideaki , Kawaguchi Rintaro , Wakasugi Tetsuro , Do Ba Hung , Kitamura Takuro , Ohbuchi Toyoaki
Published: May 2019

Purpose

We retrospectively studied the efficacy of intratympanic steroid administration in comparison with hyperbaric oxygen (HBO) therapy for idiopathic sudden sensorineural hearing loss (ISSNHL) with negative prognostic factors.

Method

We enrolled 301 patients (302 ears) with ISSNHL (average hearing level at 250–4000 Hz ≥ 40 dB; time from onset to treatment ≤ 30 days). From August 2002 to March 2009, 174 patients (174 ears) received systemic steroid plus HBO therapy (HBO group), and from June 2015 to January 2018, 127 patients (128 ears) received systemic plus intratympanic steroid (IT group). Hearing outcomes were evaluated by 6 indices: cure rate, marked-recovery rate (percent of patients with hearing gain ≥ 30 dB), recovery rate (percent of patients with hearing gain ≥ 10 dB), hearing gain, hearing level after treatment, and percent hearing improvement compared to the unaffected contralateral ear.

Results

The recovery rate was significantly higher in the IT group than in the HBO group (80.5% vs. 68.4%,
p
= .019). The IT group showed a higher recovery rate than the HBO group in patients aged ≥ 60 years (
p
= .010), patients with early (≤ 7 days from onset) treatment (
p
= .005), patients with initial hearing levels ≥ 90 dB (
p
= .037), and patients with vertigo/dizziness (
p
= .040). The IT group also showed higher hearing gain and percent hearing improvement than the HBO group in patients with vertigo/dizziness (
p
= .046 and
p
= .026, respectively).

Conclusions

Systemic plus intratympanic steroid is more effective for ISSNHL than systemic steroid plus HBO, particularly in patients with negative prognostic factors, such as old age, profound hearing loss, and/or presence of vertigo/dizziness.
New technique to measure the cavity defects of Fabry–Perot interferometers
Authors: Greco V. , Sordini A. , Cauzzi G. , Reardon K. , Cavallini F.
Published: May 2019

Context. Several astronomical instruments, for both nighttime and solar use, rely on tunable Fabry–Perot interferometers (FPIs). Knowing the exact shape of the etalons’ cavity is crucial for assessing the overall instrumental transmission profile and its possible variations during the tuning process.

Aims. We aim to define and test a technique to accurately measure the cavity defects of air-spaced FPIs, including distortions due to the spectral tuning process that are typical of astronomical observations. We further aim to develop a correction technique to maintain the shape of the cavity as constant as possible during the spectral scan. These are necessary steps to optimize the spectral transmission profile of a two-dimensional spectrograph (polarimeter) using one or more FPIs in series, and to ensure that the spectral transmission profile remains constant during typical observing conditions.

Methods. We devised a generalization of the techniques developed for the so-called phase-shifting interferometry to the case of FPI. This measuring technique is applicable to any given FPI that can be tuned via changing the cavity spacing (z-axis), and can be used for any etalon regardless of the coating’ reflectivity. The major strength of our method is the ability to fully characterize the cavity during a spectral scan, allowing for the determination of scan-dependent modifications of the plates. We have applied the measuring technique to three 50 mm diameter interferometers, with cavity gaps ranging between 600μm and 3 mm, coated for use in the visible range.

Results. The technique developed in this paper allows us to accurately and reliably measure the cavity defects of air-spaced FPIs, and of their evolution during the entire spectral scan. Our main, and unexpected, result is that the relative tilt between the two FPI plates varies significantly during the spectral scan, and can dominate the cavity defects; in particular, we observe that the tilt component at the extremes of the scan is sensibly larger than that at the center of the scan. Exploiting the capability of the electronic controllers to set the reference plane at any given spectral step, we then develop a correction technique that allows the minimization of the tilt during a complete spectral scan. The correction remains highly stable over long periods, well beyond the typical duration of astronomical observations.
Census of ρ Ophiuchi candidate members from Gaia Data Release 2
Authors: Cánovas H. , Cantero C. , Cieza L. , Bombrun A. , Lammers U. , Merín B. , Mora A. , Ribas Á. , Ruíz-Rodríguez D.
Published: May 2019

Context. The Ophiuchus cloud complex is one of the best laboratories to study the earlier stages of the stellar and protoplanetary disc evolution. The wealth of accurate astrometric measurements contained in the Gaia Data Release 2 can be used to update the census of Ophiuchus member candidates.

Aims. We seek to find potential new members of Ophiuchus and identify those surrounded by a circumstellar disc.

Methods. We constructed a control sample composed of 188 bona fide Ophiuchus members. Using this sample as a reference we applied three different density-based machine learning clustering algorithms (DBSCAN, OPTICS, and HDBSCAN) to a sample drawn from the Gaia catalogue centred on the Ophiuchus cloud. The clustering analysis was applied in the five astrometric dimensions defined by the three-dimensional Cartesian space and the proper motions in right ascension and declination.

Results. The three clustering algorithms systematically identify a similar set of candidate members in a main cluster with astrometric properties consistent with those of the control sample. The increased flexibility of the OPTICS and HDBSCAN algorithms enable these methods to identify a secondary cluster. We constructed a common sample containing 391 member candidates including 166 new objects, which have not yet been discussed in the literature. By combining the Gaia data with 2MASS and WISE photometry, we built the spectral energy distributions from 0.5 to 22 μm for a subset of 48 objects and found a total of 41 discs, including 11 Class II and 1 Class III new discs.

Conclusions. Density-based clustering algorithms are a promising tool to identify candidate members of star forming regions in large astrometric databases. By combining the Gaia data with infrared catalogues, it is possible to discover new protoplanetary discs. If confirmed, the candidate members discussed in this work would represent an increment of roughly 40–50% of the current census of Ophiuchus.
Hämophagozytische Lymphohistiozytose – eine seltene, aber
schwere Komplikation
Authors: Lachmann Gunnar , Brunkhorst Frank M.
Published: May 2019

Patienten mit Multiorganversagen oder Sepsis, die nur unzureichend auf eine
antiinfektive Therapie ansprechen oder bei denen keine infektiöse Ursache
erkennbar ist, könnten als Ursache das Hyperinflammationssyndrom
Hämophagozytische Lymphohistiozytose entwickelt haben. Dieses syndromale
Krankheitsbild verläuft klinisch ähnlich der Sepsis und endet aufgrund der
verzögerten Diagnosestellung mit irreversiblem Organversagen oft letal, wobei
die Erkrankung auch im Rahmen einer Sepsis entstehen kann. Die Kenntnis dieses
Syndroms ist für das Überleben der Patienten von herausragender Bedeutung.
Vom Betroffenen zum Helfer
Authors: Trumann Arne
Published: May 2019

Autor Arne Trumann erlitt im Alter von 44 Jahren einen septischen Schock. Obwohl
jeder Verlauf einer Sepsis anders ist, macht sein Fall in vielerlei Hinsicht
deutlich, dass sich an bestimmten Punkten der medizinischen Versorgung einiges
bessern muss, damit Sepsispatienten keine so schwerwiegenden Folgeschäden
davontragen müssen.
New Facile Synthesis of 3,4-Dihydroquinazoline-2(1H)-thiones by a Sequential Ugi-Azide/Staudinger/Aza-Wittig/Cyclization Reaction
Authors: Xiong Jun , Min Qing , Yao Gang , Zhang Jia-An , Yu Hai-Feng , Ding Ming-Wu
Published: May 2019

A new facile synthesis of 3,4-dihydroquinazoline-2(1H)-thiones by an Ugi-azide/Staudinger/aza-Wittig/cyclization sequence has been developed. The Ugi-azide reactions of 2-azidobenzaldehydes, amines, trimethylsilyl azide, and isocyanides produced tetrazoles, which, when treated with methyldiphenylphosphane and CS2, produced 3,4-dihydroquinazoline-2(1H)-thiones in good overall yields via a sequential Staudinger/aza-Wittig/cyclization reaction.
The multi-dimensional generalized Langevin equation for conformational motion of proteins
Authors: Lee Hee Sun , Ahn Surl-Hee , Darve Eric F.
Published: May 2019

Using the generalized Langevin equation (GLE) is a promising approach to build coarse-grained (CG) models of molecular systems since the GLE model often leads to more accurate thermodynamic and kinetic predictions than Brownian dynamics or Langevin models by including a more sophisticated friction with memory. The GLE approach has been used for CG coordinates such as the center of mass of a group of atoms with pairwise decomposition and for a single CG coordinate. We present a GLE approach when CG coordinates are multiple generalized coordinates, defined, in general, as nonlinear functions of microscopic atomic coordinates. The CG model for multiple generalized coordinates is described by the multidimensional GLE from the Mori-Zwanzig formalism, which includes an exact memory matrix. We first present a method to compute the memory matrix in a multidimensional GLE using trajectories of a full system. Then, in order to reduce the computational cost of computing the multidimensional friction with memory, we introduce a method that maps the GLE to an extended Markovian system. In addition, we study the effect of using a nonconstant mass matrix in the CG model. In particular, we include mass-dependent terms in the mean force. We used the proposed CG model to describe the conformational motion of a solvated alanine dipeptide system, with two dihedral angles as the CG coordinates. We showed that the CG model can accurately reproduce two important kinetic quantities: the velocity autocorrelation function and the distribution of first passage times.
Effects of propagation distance and half angle on the merging of hypervelocity plasma jets
Authors: Thompson Seth , Cassibry Jason
Published: May 2019

We investigate the effects of the half angle on the intersection and merger of two plasma jets and verify the observation of the density drop and undulations at the merger interface seen in recent experiments. To perform this analysis, we employed a Smooth Particle Hydrodynamic code to model the jets and their merger. We validate the code against well-known test cases, Sod shock tube, Noh-Cylindrical implosion, and Kelvin-Helmholtz instability. These cases stress and quantify the Smoothed Particle Hydrodynamic code's ability to handle the expected physics of two jet merging. The half angle influences the shock region of the jets, but all jets merge and demonstrate density undulations along their centerline. The merged jet has velocity and density profiles consistent with experimental observations. The density drop was observed in the simulation and can be attributed to the sequence of thermal expansion of the free jets prior to the merge and subsequent density jump across the shock, where the centerline jump would be at the lowest density. A potential cause of the undulations along the centerline can be attributed to Kelvin-Helmholtz instability as it was the culprit in the simulation, although perturbations in the experiments or other causes cannot be ruled out.
Generation of long-range, near-cut-on guided resonances in composite panels
Authors: Droz Christophe , Bareille Olivier , Ichchou Mohamed N.
Published: May 2019

In this paper, near-cut-on guided resonances (GRs) are generated in a composite structure using an array of piezoelectric transducers. A GR is a type of high-order unidirectional wave mode, guided between the finite boundaries of a periodic waveguide’s cross section. Near their cut-on frequency, these waves often exhibit high chromatic dispersion and spatial decay, which compromise their potential use for wave-based inspection and structural health monitoring of advanced composites or metamaterials. A custom GR actuator is designed to achieve an accurate shape appropriation of the predicted 3D Floquet-Bloch solutions in a 3-m-long sandwich structure. An original wave conversion phenomenon is then exploited to generate almost nondispersive selected GR pulses near their cut-on frequency. Full wavefield measurements are conducted in time domain using a laser Doppler velocimeter to provide new insights into the GR near-cut-on scattering effects in the low vibroacoustic bandwidth.
W-symmetries of Ito stochastic differential equations
Authors: Gaeta G.
Published: May 2019

We discuss W-symmetries of Ito stochastic differential equations, introduced in a recent paper by Gaeta and Spadaro [J. Math. Phys. 58, 053503 (2017)]. In particular, we discuss the general form of acceptable generators for continuous (Lie-point) W-symmetry, arguing that they are related to the (linear) conformal group, and how W-symmetries can be used in the integration of Ito stochastic equations along Kozlov theory for standard (deterministic or random) symmetries. It turns out that this requires, in general, considering more general classes of stochastic equations than just Ito ones.
Analytic nuclear gradients of the algebraic-diagrammatic construction scheme for the polarization propagator up to third order of perturbation theory
Authors: Rehn Dirk R. , Dreuw Andreas
Published: May 2019

Analytic gradient expressions for the algebraic diagrammatic construction (ADC) scheme for the polarization propagator up to third order are derived using a Lagrangian approach. An implementation within the Q-CHEM electronic structure package for excited-state nuclear gradients of the ADC(2), ADC(2)-x, and ADC(3) models based on restricted and unrestricted Hartree–Fock references is presented. Details of the implementation and the applicability of the newly derived gradients for geometry optimizations and the quality of the resulting structures are discussed.
Self-propelled particle in a nonconvex external potential: Persistent limit in one dimension
Authors: Fily Yaouen
Published: May 2019

Equilibrium mapping techniques for nonaligning self-propelled particles have made it possible to predict the density profile of an active ideal gas in a wide variety of external potentials. However, they fail when the self-propulsion is very persistent and the potential is nonconvex, which is precisely when the most uniquely active phenomena occur. Here, we show how to predict the density profile of a 1D active Ornstein-Uhlenbeck particle in an arbitrary external potential in the persistent limit and discuss the consequences of the potential’s nonconvexity on the structure of the solution, including the central role of the potential’s inflection points and the nonlocal dependence of the density profile on the potential.
Controlled armoring of metal surfaces with metallodielectric patchy particles
Authors: Noguchi Tomohiro G. , Iwashita Yasutaka , Kimura Yasuyuki
Published: May 2019

A patchy colloidal particle possesses distinctive regions with different physical or chemical properties on its surface and thus exhibits anisotropic interactions with another particle or object. By utilizing the large van der Waals attraction between metal surfaces and the electric double layer repulsion originating from surface charge, we succeeded in controlling the adsorption behavior of metallodielectric particles (MDPs), which were composed of dielectric spheres each with a thin gold patch modified with dissociable groups, to gold surfaces. When MDPs were dispersed on a dielectric substrate with a thick gold pattern in aqueous solution, the particles selectively adsorbed onto the gold surface of the substrate at a moderate salt concentration. Furthermore, when MDPs were mixed with large particles coated with a thick gold film, MDPs adsorbed on the gold surface at a moderate salt concentration and formed a monolayer. In the monolayer, gold patches of MDPs bonded to the gold surface and the dielectric surface of MDPs faced outward. In other words, this monolayer was a solid dielectric layer formed on the metal surface of a large particle. Such selectivity, i.e., that a gold patch of an MDP bonded to a gold surface but the patches did not bond to each other, was realized by controlling the thickness and surface charge of gold patches.
Background-free time-resolved coherent Raman spectroscopy (CSRS and CARS): Heterodyne detection of low-energy vibrations and identification of excited-state contributions
Authors: Kolesnichenko Pavel V. , Tollerud Jonathan O. , Davis Jeffrey A.
Published: May 2019

Coherent Raman scattering (CRS) spectroscopy techniques have been widely developed and optimized for different applications in biomedicine and fundamental science. The most utilized CRS technique has been coherent anti-Stokes Raman scattering (CARS), and more recently, stimulated Raman scattering. Coherent Stokes Raman scattering (CSRS) has been largely ignored mainly because it is often strongly affected by fluorescence, particularly for resonance enhanced measurements. However, in the cases of resonant excitation, the information contained in the CSRS signal can be different and complementary to that of CARS. Here, we combine the approaches of pulse shaping, interferometric heterodyne detection, 8-step phase cycling, and Fourier-transform of time-domain measurements, developed in CARS and 2D electronic spectroscopy communities, to measure resonant CSRS and CARS spectra using a titanium:sapphire oscillator. The signal is essentially background-free (both fluorescent and nonresonant background signals are suppressed) with high spectral resolution and high sensitivity and can access low-energy modes down to ∼30 cm−1. We demonstrate the ability to easily select between CSRS and CARS schemes and show an example in which acquisition of both CSRS and CARS spectra allows vibrational modes on the excited electronic state to be distinguished from those on the ground electronic state.
Probing molecular bond-length using molecular-frame photoelectron angular distributions
Authors: Fukuzawa Hironobu , Lucchese Robert R. , Liu Xiao-Jing , Sakai Kentaro , Iwayama Hiroshi , Nagaya Kiyonobu , Kreidi Katharina , Schöffler Markus S. , Harries James R. , Tamenori Yusuke , Morishita Yuichiro , Suzuki Isao H. , Saito Norio , Ueda Kiyoshi
Published: May 2019

The molecular-frame photoelectron angular distributions (MFPADs) in O 1s photoemission from CO2 molecule were measured. Patterns due to photoelectron diffractions were observed in the MFPADs. The polarization-averaged MFPADs were compared with theoretical calculation and were found to be useful in determining the molecular bond-length, which is a component to determine molecular structures.
Persistence of large magnetodielectric coupling anomalies and multiferroicity for significant dilution of Tb sublattice by Y in Tb2BaNiO5
Authors: Upadhyay Sanjay K. , Sampathkumaran E. V.
Published: May 2019

We report temperature dependence of dc magnetization, heat capacity, dielectric, magnetodielectric (MDE) coupling, and pyrocurrent on polycrystalline specimens resulting from a gradual dilution of Tb sublattice by Y in an exotic multiferroic Haldane spin-chain system, Tb2BaNiO5, viz., for the series Tb2−xYxBaNiO5 (x = 0.1, 0.2, 0.5, 1, and 1.5). Among various observations, the ones to be stressed are as follows: (i) The Néel temperature (TN1 = 63 K) and the second magnetic feature occurring at (TN2) 25 K get reduced to lower temperatures with increasing x in a linear fashion, with a concomitant lowering of multiferroicity onset temperature below TN2, scaling essentially with x. This finding emphasizes that local effects due to Tb play a major role on multiferroicity. Clearly, 4f dominates to determine this phenomenon—a rare finding in this field. (ii) The magnitude of the change (Δɛ′) in the dielectric constant surprisingly gets maximized for x = 0.1 with respect to that of the parent compound, attaining a relatively large value of about 22% at 15 K for a field of 100 kOe, thereby revealing that a delicate balance of nonmagnetic doping or defects in favorable cases can enhance MDE coupling. (iii) Nonmonotonic changes in Δɛ′ with a magnetic field, also a changing sign for some compositions, reveal interesting metamagnetodielectric behavior. (iv) The magnetoelectric behavior of x = 1.5 composition is found to be somewhat peculiar with respect to that of other compositions. Thus, this solid solution reveals exotic magneto(di)electric coupling anomalies.
CASSCF linear response calculations for large open-shell molecules
Authors: Helmich-Paris Benjamin
Published: May 2019

The complete active space self-consistent-field (CASSCF) linear response method for the simulation of ultraviolet-visible (UV/Vis) absorption and electronic circular dichroism (ECD) spectra of large open-shell molecules is presented. By using a one-index transformed Hamiltonian, the computation of the most time-consuming intermediates can be pursued in an integral-direct fashion, which allows us to employ the efficient resolution-of-the-identity and overlap-fitted chain-of-spheres approximation. For the iterative diagonalization, pairs of Hermitian and anti-Hermitian trial vectors are used which facilitate, on the one hand, an efficient solution of the pair-structured generalized eigenvalue problem in the reduced space, and on the other hand, make the full multiconfigurational random phase approximation as efficient as the corresponding Tamm-Dancoff approximation. Electronic transitions are analyzed and characterized in the particle-hole picture by natural transition orbitals that are introduced for CASSCF linear response theory. For a small organic radical, we can show that the accuracy of simulated UV/Vis absorption spectra with the CASSCF linear response approach is significantly improved compared to the popular state-averaged CASSCF method. To demonstrate the efficiency of the implementation, the 50 lowest roots of a large Ni triazole complex with 231 atoms are computed for the simulated UV/Vis and ECD spectra.
An accurate and rapid method for calculating hydration free energies of a variety of solutes including proteins
Authors: Hikiri Simon , Hayashi Tomohiko , Inoue Masao , Ekimoto Toru , Ikeguchi Mitsunori , Kinoshita Masahiro
Published: May 2019

A new method is developed for calculating hydration free energies (HFEs) of polyatomic solutes. The solute insertion is decomposed into the creation of a cavity in water matching the geometric characteristics of the solute at the atomic level (process 1) and the incorporation of solute-water van der Waals and electrostatic interactions (process 2). The angle-dependent integral equation theory combined with our morphometric approach and the three-dimensional interaction site model theory are applied to processes 1 and 2, respectively. Neither a stage of training nor parameterization is necessitated. For solutes with various sizes including proteins, the HFEs calculated by the new method are compared to those obtained using a molecular dynamics simulation based on solution theory in energy representation (the ER method developed by Matubayasi and co-workers), currently the most reliable tool. The agreement is very good especially for proteins. The new method is characterized by the following: The calculation can rapidly be finished; a solute possessing a significantly large total charge can be handled without difficulty; and since it yields not only the HFE but also its many physically insightful energetic and entropic components, it is best suited to the elucidation of mechanisms of diverse phenomena such as the receptor-ligand binding, different types of molecular recognition, and protein folding, denaturation, and association.
Nonlinearity-based circulator
Authors: D'Aguanno Giuseppe , Sounas Dimitrios L. , Saied Hady M. , Alù Andrea
Published: May 2019

Commercially available nonreciprocal devices, such as isolators and circulators, play a fundamental role in communication systems. Since they commonly rely on magnetic materials, they tend to become bulky, expensive, and difficult to be integrated in conventional microelectronic circuits. Here, we explore the functionality of a magnetic-free circulator where reciprocity is broken by suitable geometric asymmetries combined with tailored nonlinearities. We show that it is possible to operate a fully passive coupled resonator system without external bias like a circulator for pulsed signals impinging at its ports within a desired range of intensities. The functionality can be applied to a variety of physical systems, ranging from electronics to photonics and acoustics.
Test charge response and correlations in multi-ion plasmas
Authors: Ali S.
Published: May 2019

The interaction potentials caused by a pair of moving test charges are studied in collisionless unmagnetized multi-ion plasmas, containing the electrons, singly ionized positive ions, and two negative ions. Starting from the Vlasov-Poisson coupled equations, a generalized electrostatic potential is obtained for a pair of test charges moving with constant velocities along the z-axis. Based on the speeds and correlations of test charges, the cases of slow, fast, and resonating test charge response are specifically studied and analyzed. If the test charges move with velocities much slower than the thermal speeds of all plasma species in multi-ion plasmas, then a short-range Debye-Hückel (DH) shielding potential appears to decay exponentially with the distance, whereas the long-range far-field (FF) potential varies as the inverse cube of the distance from test charges. The shielding phenomenon does not occur if the test charges move much faster than the plasma thermal speeds. However, the oscillatory wakefield (WF) potentials only exist behind the test charges when their speeds resonate with the speed of ion-acoustic waves. Numerically, it is revealed that the profiles of DH, FF, and WF potentials are significantly affected by the multi-ion plasma parameters and correlation effects. The results might be helpful for understanding the shielding phenomena, particle-particle and wave-particle interactions in multi-ion laboratory plasmas.