bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced pseudotargeted analysis using a segment data dependent acquisition strategy by liquid chromatography–tandem mass spectrometry for a metabolomics study of liquiritin in the treatment of depression
Authors: Yang Jina , Jin Wenbin , Liu Danyang , Zhong Qisheng , Zhou Ting
Published: March 2020

An enhanced pseudotargeted method using a segment data‐dependent acquisition mode based on ultra‐high performance liquid chromatography–tandem mass spectrometry was developed. This segment data dependent acquisition‐based pseudotargeted method could improve the detection of co‐eluted ions and extend the coverage of analytes. A set of 502 multiple reaction monitoring channels were obtained by this segment strategy, which was twice the number created by the traditional data‐dependent acquisition mode. Compared with the untargeted method, the pseudotargeted profiling demonstrated higher sensitivity and higher precision. More than 90% of the metabolites detected by the enhanced pseudotargeted method had relative standard deviations less than 15%. The segment data dependent acquisition‐based pseudotargeted method was successfully applied to the metabolomics study of the depressed rats with the treatment of liquiritin. Forty‐seven differential metabolites were screened and five metabolic pathways were found to be related to depression including retinol metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism, terpenoid backbone biosynthesis, and lysine degradation. The segment data dependent acquisition‐based pseudotargeted method widened the coverage of metabolites with good sensitivity and precision, which exhibited great potential in the discovery of differential metabolites in metabolomics studies.
How you see yourself influences your color preference: Effects of self‐construal on evaluations of color combinations
Authors: Jeon Eunmi , Han Youngjee , Nam Myungwoo
Published: March 2020

The present study examines the role of self‐construal in the preference for analogous versus complementary color combinations. The majority of previous research on color has been limited to exploration of single colors. However, designers and marketers often use a mix of colors whose harmony must be taken into consideration, which includes choosing whether to use colors placed next to each other on the color wheel (analogous combination) or to combine colors that are opposite each other (complementary combination). The current study proposes that self‐construal influences the perception of and preference for color combinations. Individuals with interdependent self‐construals tend to focus on relational similarity and value harmony, whereas individuals with independent self‐construals tend to view objects as discrete and disconnected. Accordingly, the authors posited that individuals with interdependent self‐construals would be more sensitive to the relationship between two colors and perceive analogous colors as more harmonious, thus preferring brands and products featuring analogous colors to those featuring complementary colors. Contrariwise, individuals with independent self‐construals would display indifference in this regard. The hypotheses were confirmed in four studies employing various colors to form analogous and complementary color combinations.
Transdermal drug delivery and patches—An overview
Authors: Bird David , Ravindra Nuggehalli M.
Published: March 2020

Transdermal drug delivery is a multibillion‐dollar industry, with an average of one transdermal being approved by the Federal Drug Administration every 2.2 years. The first transdermal drug patch was approved by the Food and Drug Administration approximately 40 years ago, meriting a systematic review of the technology, industry and products. Patches are a unique technique offering the ability for transdermal drug delivery systems on demand. The limiting factors for transdermal delivery systems are the physicochemical and pharmacokinetic properties of an active drug enabling delivery across the skin. An overview of the skin anatomy and natural barrier it presents for pharmaceuticals to be administered transdermally is presented in this study. The clinical trials, patents, commercialization, advantages and limitations of the technology are examined. Finally, 3D printing technologies are discussed, emphasizing the tailorable transdermal system, enhancing bioavailability and revolutionizing current ‘one size fits all’ manufacturing approach with capabilities that are utilized throughout the drug development timeline.
A pathogen imprinted hybrid polymer capacitive sensor for selective Escherichia coli detection
Authors: Mugo Samuel M. , Lu Weihao , Dhanjai Dhanjai
Published: March 2020

A versatile pathogen imprinted polymer electrochemical sensor has been developed for Escherichia coli detection. The sensor is based on layer by layer assembly of multi‐walled carbon nanotubes (CNT), nanocellulose (CNC) films, integrated with polyaniline (PANI) doped phenylboronic acid (PBA). The sensing layer is a poly(methacrylic acid) based pathogen microcontact imprinted polymer (PIP). The PIP@PBA/PANI@CNT/CNC sensor exhibits a high affinity towards E. coli in real biological matrices, while effective in discriminating E. coli amidst other bacteria. Using capacitance and impedance as transduction methods, the PIP sensor recorded a low limit of E. coli detection of 8.7 ± 0.5 cfu/ml, with a rapid response of ≤5 min.
Purine and pyrimidine transporters of pathogenic protozoa – conduits for therapeutic agents
Authors: Campagnaro Gustavo D. , de Koning Harry P.
Published: March 2020

Purines and pyrimidines are essential nutrients for any cell. Most organisms are able to synthesize their own purines and pyrimidines, but this ability was lost in protozoans that adapted to parasitism, leading to a great diversification in transporter activities in these organisms, especially for the acquisition of amino acids and nucleosides from their hosts throughout their life cycles. Many of these transporters have been shown to have sufficiently different substrate affinities from mammalian transporters, making them good carriers for therapeutic agents. In this review, we summarize the knowledge obtained on purine and pyrimidine activities identified in protozoan parasites to date and discuss their importance for the survival of these parasites and as drug carriers, as well as the perspectives of developments in the field.
Rapid detection by hydrops panel of Noonan syndrome with PTPN11 mutation (p.Thr73Ile) and persistent thrombocytopenia
Authors: Schönfeld Mascha , Selig Mareike , Russo Alexandra , Lindner Christine , Kampmann Christoph , Mildenberger Eva , Whybra Catharina
Published: March 2020

Background

Nonimmune hydrops fetalis (NIHF) is still a challenging diagnosis. The differential diagnosis is extensive and the success of identifying a cause depends on the thoroughness of efforts to establish a diagnosis. For the early diagnosis of NIHF, a virtual gene panel diagnostic tool was developed. The female premature baby in question was delivered via emergency cesarean at 30 + 1 weeks of gestational age (GA) due to rapidly developing NIHF to a healthy mother. The family history was noncontributory.

Methods

DNA of the family was extracted and sequenced by the virtual hydrops panel with whole‐exome sequencing.

Results

The hydrops panel revealed Noonan syndrome (NS) with a germline mutation in PTPN11 c.218C>T (p.Thr73Ile).

Conclusion

The diagnosis of our patient was rapidly confirmed by the hydrops panel. The variant of c.218C>T (p.Thr73Ile) has not yet been described in literature relating to NIHF. Only a few case reports of this variant are known. This particular mutation is associated with Noonan syndrome, congenital heart defect and persistent thrombocytopenia. Few reveal juvenile myelomonocytic leukemia.
Experimental verification the electron return effect around spherical air cavities for the MR‐Linac using Monte Carlo calculation
Authors: Shortall J. , Vasquez Osorio E. , Aitkenhead A. , Berresford J. , Agnew J. , Budgell G. , Chuter R. , McWilliam A. , Kirkby K. , Mackay R. , van Herk M.
Published: March 2020

Purpose

Dose deposition around unplanned air cavities during magnetic resonance‐guided radiotherapy (MRgRT) is influenced by the electron return effect (ERE). This is clinically relevant for gas forming close to or inside organs at risk (OARs) that lie in the path of a single beam, for example, intestinal track during pelvic treatment. This work aims to verify Monte Carlo calculations that predict the dosimetric effects of ERE around air cavities. For this, we use GafChromic EBT3 film inside poly‐methyl methacrylate (PMMA) –air phantoms.

Method

Four PMMA phantoms were produced. Three of the phantoms contained centrally located spherical air cavities (0.5, 3.5, 7.5 cm diameter), and one phantom contained no air. The phantoms were split to sandwich GafChromic EBT3 film in the center. The phantoms were irradiated on an Elekta Unity system using a single 10 × 10 cm2 7‐MV photon beam under the influence of a 1.5‐T transverse magnetic field. The measurements were replicated using the Elekta Monaco treatment planning system (TPS). Gamma analysis with pass criteria 3%/3 mm was used to compare the measured and calculated dose distributions. We also consider 3%/2 mm, 2%/3 mm, and 2%/2 mm pass criteria for interest.

Results

The gamma analysis showed that >95% of the points agreed between the TPS‐calculated and measured dose distributions, using 3%/3 mm criteria. The phantom containing the largest air cavity had the lowest agreement, with most of the disagreeing points lying inside the air cavity (dose to air region).

Conclusions

The dose effects due to ERE around spherical air cavities are being calculated in the TPS with sufficient accuracy for clinical use.
Empirical Evaluation of Oxytetracycline and F1 Genetics to Differentiate Stocked from Wild Largemouth Bass
Authors: Bunch Aaron J. , Donovan Brady P. , Hoogakker Frederick J. , Peatman Eric
Published: March 2020

Evaluation and monitoring of stocking effectiveness is essential to make informed fisheries management decisions. Chemical marking, such as oxytetracycline (OTC), is often used for differentiating stocked from wild fish but has inherent error in mark longevity and otolith evaluation. Genetic analysis of recaptures provides a viable alternative. In this study, fingerlings (~50 mm TL) of F1 intergrade Largemouth Bass Micropterus salmoides (Florida Largemouth Bass M. salmoides floridanus × Northern Largemouth Bass M. salmoides salmoides) were marked with OTC via immersion and stocked into the Chickahominy River, Virginia, from 2005 to 2007 and more recently from 2015 to 2017, totaling 595,000 fish. We collected Largemouth Bass in 2015 and 2017 during long-term monitoring on the tidal portion of the Chickahominy River in Virginia. Fish were retained for aging, OTC evaluation, and genetic analysis. Although precision (i.e., agreement) was high (95%) when comparing the two methods, by establishing a baseline number of known recaptures (N = 19 samples verified by genetics), we determined that detection probability (accuracy) was 63%. Differentiating stocked from wild fish with genetics provides advantages over OTC immersion for stocking evaluations, including potential cost and labor savings. Future studies should routinely incorporate an evaluation of tagging detection rate to accurately adjust percent contribution estimates.
Evaluation of Alligator Gar Broodfish Collections in the Lower Mobile–Tensaw Delta, Alabama
Authors: Armstrong David L. , Purcell Tommy R.
Published: March 2020

In Alabama, Alligator Gar Atractosteus spatula populations have experienced a decline in abundance and due to their limited distribution are classified as a nongame species of moderate conservation concern. Conservation management plans have included creel limits and stocking to augment a diminished population within the lower Alabama River. Our objective was to evaluate gill-net efficacy on catch and the environmental variables associated with improving broodfish capture rates for hatchery propagation. Broodfish collections were initiated and completed over 75 sample dates between March 2005 and April 2015. Collectors utilized multifilament gill nets consisting of three mesh sizes (101.6, 127.0, and 152.4 mm) and three net lengths (22.9, 30.5, and 61.0 m). Gill nets (n = 569) expended 2,173 h of soak time, resulting in the capture of 101 individuals (TL range = 1,020–2,210 mm). Catch was highest for the smallest mesh size, but net panel length did not influence catch rates. Median fish lengths increased with larger mesh sizes. Catch declined more than sevenfold for net soaks of 1 h or more, and the proportion of successful gill nets declined threefold for longer soak times. Examination of environmental conditions during and prior to the setting of gill nets demonstrated that fish capture success was in part influenced by various aspects of tidal current and water temperature. Catch success was 68% when nets were set at water temperatures of at least 20°C and when at least 50% of net soak time occurred during rising tides. However, success was lower when nets were set at temperatures less than 20°C, capturing Alligator Gar in 44% of all soaks and 37% for those on falling or slack tides. Agencies involved in hatchery propagation programs should continually evaluate field sampling methods, use of collection gear, and environmental conditions to increase broodfish catch rates and improve staff efficacy.
Evidence for Protein Leverage in Children and Adolescents with Obesity
Authors: Saner Christoph , Tassoni Daniella , Harcourt Brooke E. , Kao Kung‐Ting , Alexander Erin J. , McCallum Zoe , Olds Timothy , Rowlands Alex V. , Burgner David P. , Simpson Stephen J. , Raubenheimer David , Senior Alistair M. , Juonala Markus , Sabin Matthew A.
Published: March 2020

Objective

The aim of this study was to test the protein leverage hypothesis in a cohort of youth with obesity.

Methods

A retrospective study was conducted in a cohort of youth with obesity attending a tertiary weight management service. Validated food questionnaires revealed total energy intake (TEI) and percentage of energy intake from carbohydrates (%EC), fats (%EF), and proteins (%EP). Individuals with a Goldberg cutoff ≥ 1.2 of the ratio of reported TEI to basal metabolic rate from fat‐free mass were included. A subgroup had accelerometer data. Statistics included modeling of percentage of energy from macronutrients and TEI, compositional data analysis to predict TEI from macronutrient ratios, and mixture models for sensitivity testing.

Results

A total of 137 of 203 participants were included (mean [SD] age 11.3 [2.7] years, 68 females, BMI z score 2.47 [0.27]). Mean TEI was 10,330 (2,728) kJ, mean %EC was 50.6% (6.1%), mean %EF was 31.6% (4.9%), and mean %EP was 18.4% (3.1%). The relationship between %EP and TEI followed a power function (L coefficient −0.48; P < 0.001). TEI was inversely associated with increasing %EP. In the subgroup with < 60 min/d of moderate to vigorous physical activity (n = 48), lower BMI z scores were associated with higher %EP and moderate %EC.

Conclusions

In youth with obesity, protein dilution by either carbohydrates or fats increases TEI. Assessment of dietary protein may be useful to assist in reducing TEI and BMI in youth with obesity.
Synthesis of novel fluorescent molecule and its polymeric form with aniline as fluorescent and supercapacitor electrode materials
Authors: Karri Sangam Naidu , Ega Sai Prasad , Srinivasan Palaniappan
Published: March 2020

In this study, a fluorescent material, 2‐naphthyl‐4‐amino benzoate, is synthesized by the esterification of 4‐aminobenzoic acid with 2‐naphthol. This molecule is used in the bulk polymerization of aniline, which results in the formation of poly(aniline‐2‐naphthyl‐4‐aminobenzoate). For comparison, polyaniline and also poly(aniline‐4‐aminobenzoic acid) salts are prepared via bulk polymerization. Formation and properties of these polymeric materials are evaluated by Fourier‐transform infrared (FT‐IR), 13C nuclear magnetic resonance, matrix‐assisted laser desorption ionization, UV‐Vis, Fluorescence, X‐ray diffraction (XRD), Field emission‐scanning electron microscopy (FE‐SEM), Differential scanning calorimetry (DSC), thermogravimetric analysis, electrical resistance and electrochemical techniques. P(ANI‐2NA4ABA) is obtained in nanofiber morphology in 106 wt% yield with respect to the amount of aniline used with comparable conductivity of conventional polyaniline salts. This polymer salt is stable up to 220°C and indicates melting at 146°C on heating and crystal formation at 128°C on cooling. This polymer shows higher wavelength fluorescence compared to the conventional polyaniline salts. This polymer is used as an electrode material without binder, which shows a specific capacitance of 360 F g−1 at 0.25 A g−1.
Thermoset modified with polyethersulfone: Characterization and control of the morphology
Authors: Mathis Eléonore , Michon Marie‐Laure , Billaud Claude , Grau Pauline , Bocahut Anthony , Vergelati Caroll , Long Didier R.
Published: March 2020

Thermoset (TS) epoxy resins can be toughened with a thermoplastic (TP) for high‐performance applications. The final structure morphology has to be controlled to achieve high mechanical properties and high impact resistance. Four polyethersulfone‐modified epoxy resins are considered. They consist of different epoxy monomer structure (TGAP, triglycidyl‐p‐aminophenol and TGDDM, tetraglycidyl diaminodiphenylmethane) and a fixed amount of thermoplastic, and they are cured with two different amounts of curing agent. A reaction‐induced phase separation occurs for all formulations generating morphologies, different in shapes and scales. The aim is to control the final morphology and in particular its dominant length scale. This morphology depends on the phase separation process, from the initiation to its final stage. The initiation relies on the relative miscibility of the components and on the stoichiometry between epoxy and curing agent. The kinetics depends on the viscosity of the systems. The different morphologies are characterized by electron microscopy or neutron scattering. Dynamic mechanical analysis allows confirming the presence of a phase separation even when it is not observable by electron microscopy. Vermicular morphologies with few hundreds nanometer width are obtained for the systems containing the TGAP as epoxy monomer. Systems formulated with TGDDM presents morphologies on much smaller scale of order a few tens of nanometers. We interpret the different sizes of the morphologies as a consequence of a larger viscosity for the TGDDM systems as compared to the TGAP ones rather than by a latter initiation of phase separation.
Winter air temperature during the Holocene optimum in the north‐eastern part of the east European plain based on ice wedge stable isotope records
Authors: Vasil'chuk Yurij K. , Budantseva Nadine A. , Vasil'chuk Alla C. , Chizhova Julia N.
Published: March 2020

Early Holocene winter air temperatures have been reconstructed for the north‐eastern part of the East European Plain using stable isotope (δ18O and δ2H) records of syngenetic ice wedges. We show that ice wedges here actively grew synchronously with accumulation of peatlands in bogged and forested depressions between 10 and 8 cal ka BP, corresponding to the early Holocene Thermal Maximum. The slope of the δ2H–δ18O regression line is close to the global meteoric water line. This suggests the preservation of winter precipitation signal in the ice wedge with minor isotope transformation. The low range of stable isotope values in the ice wedge indicates quite stable winter climate conditions, favorable to ice wedge growth. Reconstructed mean winter air temperature was close to modern, but it is assumed that air temperature of the coldest winter month was lower and more stable than at present.
Impact of Antisite Defect Complex on Optical and Electrical Properties of Ag2ZnSnSe4 Thin Films
Authors: Patil Rhishikesh Mahadev , Nagapure Dipak Ramdas , Hema Chandra Galli , Subbaiah Y. P. Venkata , Gupta Mukul , Rao R. Prasada
Published: March 2020

Herein, preparation of Ag2ZnSnSe4 (AZTSe) thin films using physical vapor deposition followed by selenization in a quartz tube with rapid thermal process (RTP) is reported. The precursor stacks, [Sn/Se/ZnSe/Se/Ag/Se] × 4, are deposited onto the glass substrate at 100 °C using the combination of thermal and e‐beam evaporation methods. The post selenization of precursors is conducted at different temperatures (300–425 °C). The X‐ray diffraction and Raman spectra of the precursor films selenized at 400 °C reveal the formation of single‐phase AZTSe, exhibiting a kesterite structure with a preferred orientation along the (112) plane. These films show larger grains of ≈230 nm with the homogeneous distribution of Ag, Zn, Sn, and Se across the film thickness. The precursor films selenized at temperatures ≤400 °C show the fundamental absorption edge of AZTSe (Eg = 1.36–1.44 eV) as well as an additional adsorption edge (Eadd = 1.31–1.32 eV) corresponding to ZnSn + SnZn defect complex. The Hall effect measurement indicates n‐type conductivity irrespective of selenization temperature. For films selenized at 400 °C, the carrier concentration is decreased to 2.83 × 1011 cm−3 and results in a high mobility of 73.9 cm2(V s)−1, which is attributed to the reduction of SnZn defects.
Spike‐Timing‐Dependent and Spike‐Shape‐Independent Plasticities with Dopamine‐Like Modulation in Nanocomposite Memristive Synapses
Authors: Nikiruy Kristina E. , Surazhevsky Igor A. , Demin Vyacheslav A. , Emelyanov Andrey V.
Published: March 2020

In hardware neuromorphic systems (NSs), memristors are used as synaptic connections. In such systems, spike‐timing‐dependent plasticity (STDP) is a promising local learning rule. Herein, STDP is studied in a system composed of a pair of hardware or software neurons connected by a (CoFeB)x(LiNbO3)100−x nanocomposite‐based memristor. The dopamine‐like modulation of memristor‐based STDP is implemented simply by the change in the polarity of spikes generated by artificial neurons operating in the inhibitory or excitatory mode. This modulation method is shown to be compatible with hardware neurons, different spike shapes, and is used in spiking NSs with bioinspired dopamine‐like reinforcement learning.
Template‐Free Synthesis and Growth Mechanism of Hollow Structure SnO2 and Fabrication of Core‐Shell SnO2@ZnO
Authors: Shin Se-Hee , Song Joo-Mi , Kim Sun-Woo , Shin Jae-Kyung , Lee Sang-Min , Ro Jae-Chul , Suh Su-Jeong
Published: March 2020

Zinc oxide (ZnO) and tin oxide (SnO2) are widely used in gas sensors and photocatalysis owing to their wide bandgaps, high electron mobilities, and thermal stabilities. Herein, a hollow structure of SnO2 is synthesized without a template by varying the precursor concentration and synthesis time, and its growth mechanism is studied. In addition, a core‐shell structure fabricated with SnO2 and ZnO, which is the heterostructure formed between the two metal oxides, is synthesized to compensate for the inferior properties of SnO2.
The effect of resveratrol supplementation on serum levels of asymmetric de‐methyl‐arginine and paraoxonase 1 activity in patients with type 2 diabetes: A randomized, double‐blind controlled trial
Authors: Tabatabaie Mahtab , Abdollahi Shima , Salehi‐Abargouei Amin , Clark Cain C. T. , Karimi‐Nazari Elham , Fallahzadeh Hossein , Rahmanian Masoud , Mozaffari‐Khosravi Hassan
Published: March 2020

The present study sought to investigate the effect of micronized resveratrol supplementation on serum levels of asymmetric de‐methyl‐arginine (ADMA) and paraoxonase‐1 (PON1) activity in patients with type 2 diabetes (T2D). In this double‐blinded randomized trial, 76 patients with T2D were recruited. Participants were randomly assigned to consume 1,000 mg resveratrol or placebo capsules (methylcellulose) per day, for 8 weeks. Serum levels of ADMA and PON1 enzyme activity were measured at the beginning and end of the intervention using the enzyme‐linked immunosorbent assay method. In total, 71 participants completed the study. Our results showed that resveratrol significantly decreased serum levels of ADMA (−0.16 ± 0.11, p < .001) and improved PON1 enzyme activity (15.39 ± 13.99, p < .001) compared with placebo, after adjusting for confounding factors (age, sex, and baseline body mass index). Our findings suggest that 8‐week resveratrol supplementation may produce beneficial effects on serum levels of ADMA and PON1 enzyme activity in patients with T2DM. However, further research is needed to confirm the veracity of these results.
Janus kinase 2 inhibition by Licochalcone B suppresses esophageal squamous cell carcinoma growth
Authors: Song Mengqiu , Yoon Goo , Choi Joon‐Seok , Kim Eunae , Liu Xuejiao , Oh Ha‐Na , Chae Jung‐Il , Lee Mee‐Hyun , Shim Jung‐Hyun
Published: March 2020

Esophageal cancer (EC) is one of the leading causes to cancer death in the worldwide and major population of EC is esophageal squamous cell carcinoma (ESCC). Still, ESCC‐targeted therapy has not been covered yet. In the present study we have identified that Licochalcone B (Lico B) inhibited the ESCC growth by directly blocking the Janus kinase (JAK) 2 activity and its downstream signaling pathway. Lico B suppressed KYSE450 and KYSE510 ESCC cell growth, arrested cell cycle at G2/M phase and induced apoptosis. Direct target of Lico B was identified by kinase assay and verified with in vitro and ex vivo binding. Computational docking model predicted for Lico B interaction to ATP‐binding pocket of JAK2. Furthermore, treatment of JAK2 clinical medicine AZD1480 to ESCC cells showed similar tendency with Lico B. Thus, JAK2 downstream signaling proteins phosphorylation of STAT3 at Y705 and S727 as well as STAT3 target protein Mcl‐1 expression was decreased with treatment of Lico B. Our results suggest that Lico B inhibits ESCC cell growth, arrests cell cycle and induces apoptosis, revealing the underlying mechanism involved in JAK2/STAT3 signaling pathways after Lico B treatment. It might provide potential role of Lico B in the treatment of ESCC.
Probabilistic high‐impact rainfall forecasts from landfalling tropical cyclones using Warn‐on‐Forecast system
Authors: Yussouf Nusrat , Jones Thomas A. , Skinner Patrick S.
Published: March 2020

Intense rainfall and flash flooding from landfalling tropical cyclones (LTC) can have devastating impacts on human life and property in coastal areas. The years 2017 and 2018 are examples of how the North Atlantic LTCs can create widespread destruction in the United States. Better preparedness is needed to mitigate the impact from the violent LTCs and can be achieved by improving the accuracy of forecasts and increased lead‐time of guidance products. However, predicting the fine‐scale details of rain bands in LTC is very challenging. This study attempts to elucidate the potential of National Severe Storms Laboratory's convective‐scale ensemble analysis and prediction system, known as the Warn‐on‐Forecast System (WoFS), in improving 0–6 hr probabilistic intense rainfall forecasts from three recent LTCs in the United States. Results indicate that the frequent 15 min assimilation cycling can accurately analyse the small‐scale details from the LTC rain bands in the WoFS analyses. The WoFS 0–6 hr ensemble forecasts initialized from those analyses represent the location, intensity and spatial distribution of intense rainfall (with the potential to cause flash flooding) as well as low‐level rotation with reasonably good accuracy. The continuous flow of the frequently updated WoFS rainfall guidance has the potential to aid operational forecasters in issuing watches, warnings, and short‐term forecast products of life‐threatening LTC with higher spatial and temporal specificity.
Investigating solvent effects on the magnetic properties of molybdate ions () with relativistic embedding
Authors: Halbert Loïc , Olejniczak Małgorzata , Vallet Valérie , Severo Pereira Gomes André
Published: March 2020

We investigate the ability of mechanical and electronic density functional theory‐based embedding approaches to describe the solvent effects on nuclear magnetic resonance (NMR) shielding constants of the 95Mo nucleus in the molybdate ion in aqueous solution. From the description obtained from calculations with two‐ and four‐component relativistic Hamiltonians, we find that, for such systems, spin‐orbit coupling effects are clearly important for absolute shielding values, but for relative quantities, a scalar relativistic treatment provides sufficient estimation of the solvent effects. We find that the electronic contributions to the solvent effects are relatively modest yet decisive to provide a more accurate magnetic response of the system when compared to reference supermolecular calculations. We analyze the errors in the embedding calculations by statistical methods, as well as through a real‐space representation of NMR shielding densities, which are shown to provide a clear picture of the physical processes at play.
Mass spectral fragmentation of perfluoroacyl derivatives of half nitrogen mustards for their detection by gas chromatography/mass spectrometry
Authors: Chandra Buddhadeb , Sinha Roy Kanchan , Shaik Mahabul , Waghmare Chandrakant , Palit Meehir
Published: March 2020

Rationale

Analytical methods for the detection and identification of half nitrogen mustards (halfNMs), i.e., partially hydrolyzed products of nitrogen mustards (pHpNMs), using silyl derivatives are often associated with low sensitivity and selectivity. In order to overcome these limitations, the derivatization of halfNMs was performed using perfluoroacylation.

Methods

Two efficient derivatization techniques using trifluoroacetyl (TFA) and heptafluorobutyryl (HFB) groups were developed for the unambiguous identification of halfNMs. A mass spectral database was generated by performing gas chromatography/electron ionization mass spectrometry (GC/EI‐MS) and gas chromatography/positive chemical ionization mass spectrometry (GC/PCI‐MS). The fragmentation pathways were studied by tandem mass spectrometry (MS/MS) in both EI and PCI mode.

Results

The EI‐MS spectra of the TFA and HFB derivatives of halfNMs contain intense molecular ions and fragment ions, thus making perfluoroacylation preferable to silylation. In addition, the background‐free chromatogram obtained using these derivatives provides unambiguous identification of these compounds in blind samples. The structures of the fragment ions were postulated, and the sources of significant ions were traced by performing MS/MS precursor ion scans. In the PCI‐MS spectra, along with the protonated molecule, significant peaks due to neutral losses of HF, HCl, CH3Cl and CF3COOH were observed.

Conclusions

This is the first report of the elucidation of the fragmentation pathways of perfluoroacyl derivatives of halfNMs. The complementary GC/PCI‐MS and GC/PCI‐MS/MS data will be helpful in the identification of unknown metabolites in a fast and reliable fashion.
Quantum chemical mass spectrometry: Ab initio study of b2‐ion formation mechanisms for the singly protonated Gln‐His‐Ser tripeptide
Authors: Cautereels Julie , Giribaldi Julien , Enjalbal Christine , Blockhuys Frank
Published: March 2020

Rationale

Both amide bond protonation triggering peptide fragmentations and the controversial b2‐ion structures have been subjects of intense research. The involvement of histidine (H), with its imidazole side chain that induces specific dissociation patterns involving inter‐side‐chain (ISC) interactions, in b2‐ion formation was investigated, focusing on the QHS model tripeptide.

Methods

To identify the effect of histidine on fragmentations issued from ISC interactions, QHS was selected for a comprehensive analysis of the pathways leading to the three possible b2‐ion structures, using quantum chemical calculations performed at the DFT/B3LYP/6‐311+G* level of theory. Electrospray ionization ion trap mass spectrometry allowed the recording of MS2 and MS3 tandem mass spectra, whereas the Quantum Chemical Mass Spectrometry for Materials Science (QCMS2) method was used to predict fragmentation patterns.

Results

Whereas it is very difficult to differentiate among protonated oxazolone, diketopiperazine, or lactam b2‐ions using MS2 and MS3 mass spectra, the calculations indicated that the QH b2‐ion (detected at m/z 266) is probably a mixture of the lactam and oxazolone structures formed after amide nitrogen protonation, making the formation of diketopiperazine less likely as it requires an additional step for its formation.

Conclusions

In contrast to glycine‐histidine‐containing b2‐ions, known to be issued from the backbone‐imidazole cyclization, we found that interactions between the side chains were not obvious to perceive, neither from a thermodynamics nor from a fragmentation perspective, emphasizing the importance of the whole sequence on the dissociation behavior usually demonstrated from simple glycine‐containing tripeptides.
Emerging trends and new developments in Lancang‐Mekong River: A bibliometric visualization analysis
Authors: Junlin Ren , Ziqian Peng , Xue Pan
Published: March 2020

The purpose of this study is to outline global performance, and to quantitatively evaluate the current research field hot spots, and the future trends about the Lancang‐Mekong River (LMR). Bibliometric methods are used to analyze 3,924 records retrieved from the collection of the Web of Science Core (WoS). The performance of publications, categories, countries, institutes, research hot spots and trends is analyzed in this study by applying CiteSpace and VOSviewer tools. The results revealed that publications about the LMR field have been increasing rapidly since the beginning of the 21st century. The research pertaining to LMR is mainly in the fields of environmental sciences & ecology, water resources, geology, engineering and agriculture. Vietnam, The People's Republic of China, The United States of America, Japan and Thailand get higher rankings in paper output, and Can Tho University, the Chinese Academy of Sciences, Beijing Normal University and the University of Tokyo achieve a high ranking on LMR research. In addition, further studies in research frontiers have revealed that health, security, climate change and international waters will become the new and popular directions and trends in the LMR research.
Hydrogen Generation by Solar Water Splitting Using 2D Nanomaterials
Authors: Ayyub Mohd Monis , Singh Reetendra , Rao Chintamani Nagesa Ramachandra
Published: March 2020

Hydrogen is clearly the most environment‐friendly alternative energy source available to us. The best way to produce hydrogen is to make use of the abundantly available solar power. This process is most beneficial both from energy and environmental aspects. A considerable effort is made to generate hydrogen by splitting water using a variety of inorganic catalysts, of which 2D materials are notable. Herein, a brief review of photocatalytic water splitting carried out using a variety of 2D catalysts is presented, including transition metal dichalcogenides, carbon nitride, heterostructures, and covalently cross‐linked 2D composites.
LUH-GRACE2018: A New Time Series of Monthly Gravity Field Solutions from GRACE
Authors: Koch Igor , Flury Jakob , Naeimi Majid , Shabanloui Akbar
Published: March 2020

In this contribution, we present the LUH-GRACE2018 time series of monthly gravity field solutions covering the period January 2003–March 2016. The solutions are obtained from GRACE K-Band Range Rate (KBRR) measurements as main observations. The monthly solutions are computed using the in-house developed GRACE-SIGMA software. The processing is based on dynamic orbit and gravity field determination using variational equations and consists of two main steps. In the first step, 3-hourly orbital arcs of the two satellites and the state transition and sensitivity matrices are dynamically integrated using a modified Gauss-Jackson integrator. In this step, initial state vectors and 3D accelerometer bias parameters are adjusted using GRACE Level-1B reduced-dynamic positions as observations. In the second step, normal equations are accumulated and the normalized spherical harmonic coefficients up to degree and order 80 are estimated along with arc-wise initial states, accelerometer biases and empirical KBRR parameters. Here KBRR measurements are used as main observations and reduced-dynamic positions are introduced to solve for the low frequency coefficients. In terms of error degree standard deviations as well as Equivalent Water Heights (EWH), our gravity field solutions agree well with RL05 solutions of CSR, GFZ and JPL.
Privacy Implications of Voice and Speech Analysis – Information Disclosure by Inference
Authors: Kröger Jacob Leon , Lutz Otto Hans-Martin , Raschke Philip
Published: March 2020

Internet-connected devices, such as smartphones, smartwatches, and laptops, have become ubiquitous in modern life, reaching ever deeper into our private spheres. Among the sensors most commonly found in such devices are microphones. While various privacy concerns related to microphone-equipped devices have been raised and thoroughly discussed, the threat of unexpected inferences from audio data remains largely overlooked. Drawing from literature of diverse disciplines, this paper presents an overview of sensitive pieces of information that can, with the help of advanced data analysis methods, be derived from human speech and other acoustic elements in recorded audio. In addition to the linguistic content of speech, a speaker’s voice characteristics and manner of expression may implicitly contain a rich array of personal information, including cues to a speaker’s biometric identity, personality, physical traits, geographical origin, emotions, level of intoxication and sleepiness, age, gender, and health condition. Even a person’s socioeconomic status can be reflected in certain speech patterns. The findings compiled in this paper demonstrate that recent advances in voice and speech processing induce a new generation of privacy threats.
Magnetic-Sparseness and Schrödinger Operators on Graphs
Authors: Bonnefont Michel , Golénia Sylvain , Keller Matthias , Liu Shiping , Münch Florentin
Published: March 2020

We study magnetic Schrödinger operators on graphs. We extend the notion of sparseness of graphs by including a magnetic quantity called the frustration index. This notion of magnetic-sparseness turns out to be equivalent to the fact that the form domain is an $$\ell ^{2}$$ℓ2 space. As a consequence, we get criteria of discreteness for the spectrum and eigenvalue asymptotics.
Concave power solutions of the dominative p-Laplace equation
Authors: Høeg Fredrik Arbo
Published: March 2020

In this paper, we study properties of solutions of the Dominative p-Laplace equation with homogeneous Dirichlet boundary conditions in a bounded convex domain $$\Omega $$Ω. For the equation $$-{\mathcal {D}}_p u= 1$$-Dpu=1, we show that $$\sqrt{u}$$u is concave, and for the eigenvalue problem $${\mathcal {D}}_p u + \lambda u=0$$Dpu+λu=0, we show that $$\log {u}$$logu is concave.
Testing the effectiveness of pyrazine defences against spiders
Authors: Burdfield-Steel Emily R. , Schneider Jutta M. , Mappes Johanna , Dobler Susanne
Published: March 2020

Insects live in a dangerous world and may fall prey to a wide variety of predators, encompassing multiple taxa. As a result, selection may favour defences that are effective against multiple predator types, or target-specific defences that can reduce predation risk from particular groups of predators. Given the variation in sensory systems and hunting tactics, in particular between vertebrate and invertebrate predators, it is not always clear whether defences, such as chemical defences, that are effective against one group will be so against another. Despite this, the majority of research to date has focused on the role of a single predator species when considering the evolution of defended prey. Here we test the effectiveness of the chemical defences of the wood tiger moth, a species previously shown to have defensive chemicals targeted towards ants, against a common invertebrate predator: spiders. We presented both live moths and artificial prey containing their defensive fluids to female Trichonephila senegalensis and recorded their reactions. We found that neither of the moth’s two defensive fluids were able to repel the spiders, and confirmed that methoxypyrazines, a major component of the defences of both the wood tiger moth and many insect species, are ineffective against web-building spiders. Our results highlight the variability between predator taxa in their susceptibility to chemical defences, which can in part explain the vast variation in these chemicals seen in insects, and the existence of multiple defences in a single species.
Adaptive radiotherapy and the dosimetric impact of inter- and intrafractional motion on the planning target volume for prostate cancer patients
Authors: Böckelmann Felix , Putz Florian , Kallis Karoline , Lettmaier Sebastian , Fietkau Rainer , Bert Christoph
Published: March 2020

Purpose

To investigate the dosimetric influence of daily interfractional (inter) setup errors and intrafractional (intra) target motion on the planning target volume (PTV) and the possibility of an offline adaptive radiotherapy (ART) method to correct larger patient positioning uncertainties in image-guided radiotherapy for prostate cancer (PCa).

Materials and methods

A CTV (clinical target volume)-to-PTV margin ranging from 15 mm in LR (left-right) and SI (superior-inferior) and 5–10 mm in AP (anterior-posterior) direction was applied to all patients. The dosimetric influence of this margin was retrospectively calculated by analysing systematic and random components of inter and intra errors of 31 consecutive intermediate- and high-risk localized PCa patients using daily cone beam computed tomography and kV/kV (kilo-Voltage) imaging. For each patient inter variation was assessed by observing the first 4 treatment days, which led to an offline ART-based treatment plan in case of larger variations.

Results:

Systematic inter uncertainties were larger (1.12 in LR, 2.28 in SI and 1.48 mm in AP) than intra systematic errors (0.44 in LR, 0.69 in SI and 0.80 mm in AP). Same findings for the random error in SI direction with 3.19 (inter) and 2.30 mm (intra), whereas in LR and AP results were alike with 1.89 (inter) and 1.91 mm (intra) and 2.10 (inter) and 2.27 mm (intra), respectively. The calculated margin revealed dimensions of 4–5 mm in LR, 8–9 mm in SI and 6–7 mm in AP direction. Treatment plans which had to be adapted showed smaller variations with 1.12 (LR) and 1.72 mm (SI) for Σ and 4.17 (LR) and 3.75 mm (SI) for σ compared to initial plans with 1.77 and 2.62 mm for Σ and 4.46 and 5.39 mm for σ in LR and SI, respectively.

Conclusion

The currently clinically used margin of 15 mm in LR and SI and 5–10 mm in AP direction includes inter and intra uncertainties. The results show that offline ART is feasible which becomes a necessity with further reductions in PTV margins.
Quasi-experimental evidence for the causal link between fertility and subjective well-being
Authors: Priebe Jan
Published: March 2020

This article presents causal evidence on the impact of fertility on women’s subjective well-being using quasi-experimental variation due to preferences for a mixed sibling sex composition (having at least one child of each sex). Based on a large sample of women from 35 developing countries, I find that having children increases mothers’ life satisfaction and happiness. I further establish that the positive impact of fertility on subjective well-being can be explained by related increases in mothers’ satisfaction with family life, friendship, and treatment by others.
Effective visco-elastic models of tough, doubly cross-linked, single-network polyvinyl alcohol (PVA) hydrogels
Authors: Kari Leif
Published: March 2020

An effective fractional derivative-based visco-elastic model of tough, doubly cross-linked, single-network polyvinyl alcohol (PVA) hydrogels, embodying both chemical and physical cross-links, is developed using a Mittag–Leffler relaxation function of order 1/2 while applying only three material parameters that are physically quantifiable, namely frequency for maximum loss modulus, equilibrium elastic modulus and relaxation intensity. The resulting 3-parameter shear modulus model is possible to additively split into chemical and physical parts; the split being the study focus. Physical explanations of the visco-elastic low-, mid- and high-frequency range properties, and their transitions between the frequency ranges, are given mainly in terms of the permanent chemical cross-links and the distinct adhesion–deadhesion processes of the transient physical cross-links. The latter are running from an associated Rouse mode low-frequency behaviour through a maximum adhesion–deadhesion dissipation and to an elastic, fully active cross-link high-frequency behaviour, while the former are displaying essentially an elastic, fully active cross-link behaviour throughout the frequency range. The developed model covers the full frequency range while matching measurements results remarkably well. Furthermore, the model is refined into a 4-parameter model by additively including an Abel relaxation function of order 1/2 to take into account the superimposed Rouse-type behaviour found in the measurements of the chemical cross-links in addition to their dominating elastic response, with the fourth parameter being a chemical Rouse stress intensity factor. The simple, effective visco-elastic models are suitable in predicting the mechanical properties of tough, doubly cross-linked, single-network PVA hydrogels with application potentials in tissue and noise abatement engineering.
Online dimensional control of rolled steel profiles using projected fringes
Authors: Gåsvik Kjell J. , Robbersmyr Kjell G. , Vadseth Trond
Published: March 2020

Fringe projection is a versatile method for mapping the topography of surfaces. In this paper, it is used to measure the defects on the head of railroad rails while the rails are moving. Railroad rails are made by hot rolling. The quality of the finished product is generally good, but surface texture will deteriorate with increasing temperature. A method for online inspection therefore is very desirable. In the present experiment, dimensional inspection of the railroad rails was made online while moving at a speed of 1–2 m/s. Therefore, it is important to minimize the registration time. To achieve this, we apply a method of fringe location with sub-pixel accuracy that requires only a single exposure for each registration.
A high-throughput platform for detailed lipidomic analysis of a range of mouse and human tissues
Authors: Furse Samuel , Fernandez-Twinn Denise S. , Jenkins Benjamin , Meek Claire L. , Williams Huw E. L. , Smith Gordon C. S. , Charnock-Jones D. Stephen , Ozanne Susan E. , Koulman Albert
Published: March 2020

Lipidomics is of increasing interest in studies of biological systems. However, high-throughput data collection and processing remains non-trivial, making assessment of phenotypes difficult. We describe a platform for surveying the lipid fraction for a range of tissues. These techniques are demonstrated on a set of seven different tissues (serum, brain, heart, kidney, adipose, liver, and vastus lateralis muscle) from post-weaning mouse dams that were either obese (> 12 g fat mass) or lean (<5 g fat mass). This showed that the lipid metabolism in some tissues is affected more by obesity than others. Analysis of human serum (healthy non-pregnant women and pregnant women at 28 weeks’ gestation) showed that the abundance of several phospholipids differed between groups. Human placenta from mothers with high and low BMI showed that lean placentae contain less polyunsaturated lipid. This platform offers a way to map lipid metabolism with immediate application in metabolic research and elsewhere.