bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and fabrication of a high‐precision 360° laser receiver for leveling applications
Authors: Wang Xianfan , Yang Jianhua , Huang Tengchao 
Published: April 2020

AbstractThe laser technique based sensors and actuators can provide many superior properties as noncontact, high sensitivity, remote operation, and reliable performance in contrast to other mechanical and electrical techniques. In this paper, we design and fabricate a high‐precision 360° laser receiver for leveling, especially for agricultural and construction field. The laser receiver is primarily composed of photoelectrical conversion module, electrical signal processing module, and display panel module. Based on the centroid method, the detection error of the laser receiver with respect to laser source and silicon photocell array, is analyzed and simulated. The design and fabrication process are described in detail, including the overall structure and electrical circuits. Furthermore, this fabricated laser receiver is demonstrated to be high precision through several static and dynamic tests in the distance of 10 and 50 m. Besides, this fabricated laser possesses wireless transmission function, which provides much convenient for users in remote operation.
Review of the use of NMR spectroscopy to investigate structure, reactivity, and dynamics of lead soap formation in paintings
Authors: Catalano Jaclyn , Di Tullio Valeria , Wagner Molly , Zumbulyadis Nicholas , Centeno Silvia A. , Dybowski Cecil 
Published: April 2020

AbstractHeavy metal carboxylate or soap formation is a widespread deterioration problem affecting oil paintings and other works of art bearing oil‐based media. Lead soaps are prevalent in traditional oil paintings because lead white was the white pigment most frequently chosen by old masters for the paints and in some cases for the ground preparations, until the development of other white pigments from approximately the middle of the 18th century on, and because of the wide use of lead‐tin yellow. In the latter part of the 19th century, lead white began to be replaced by zinc white. The factors that influence soap formation have been the focus of intense study starting in the late 1990s. Since 2014, nuclear magnetic resonance (NMR) studies have contributed a unique perspective on the issue by providing chemical, structural, and dynamic information about the species involved in the process, as well as the effects of environmental conditions such as relative humidity and temperature on the kinetics of the reaction(s). In this review, we explore recent insights into soap formation gained through solid‐state NMR and single‐sided NMR techniques.
Implications of age and sex determinations of ancient Maya sacrificial victims at Midnight Terror Cave
Authors: Verdugo Cristina , Zhu Kimberly , Prout Michael , Broomandkhoshbacht Nasreen , Galloway Alison , Fehren‐Schmitz Lars , Brady James E. 
Published: April 2020

AbstractThe prurient element in the popular notion of the ancient Maya sacrifice of “beautiful virgins” during the first half of the 20th century appears to have made researchers wary of studying women in human sacrifice. Interest in human sacrifice arose in the 1990s along with the formulation of the warfare hypothesis for the collapse of Maya civilization so that models of human sacrifice often assumed that victims were largely male war captives. The present study reports on the detailed examination of all the pelvises in the Midnight Terror Cave skeletal assemblage, using osteological and paleogenomic techniques to shed light on the age and sex composition of sacrificed individuals. Our analysis demonstrates the presence of both males and females ranging from subadult to older adult ages. All four paleogenomic sex determinations on samples from subadults were determined female. Additionally, results indicate females fall into two age categories suggesting that sacrificed women may have served as deity impersonators in rituals dedicated to female deities.
Intensive Care Unit Delirium in Surgical Patients Is Associated with Upregulation in Tryptophan Metabolism
Authors: Voils Stacy A. , Shoulders Bethany R. , Singh Sonal , Solberg Laurence M. , Garrett Timothy J. , Frye Reginald F. 
Published: April 2020

IntroductionIn intensive care unit (ICU) patients, delirium is frequent, occurs early in ICU admission, and is associated with poor outcomes. Risk models based on clinical factors have shown variable performance in terms of predictive ability. Identification of a candidate biomarker that associates with delirium may lead to a better understanding of disease mechanism, validation biomarker studies, and the ability to develop targeted interventions for prevention and treatment of delirium. This study analyzed metabolite concentrations early in the course of ICU admission to assess the association with delirium onset.MethodsWithin 24 hours of ICU admission, blood samples for global and targeted metabolomics analyses in adult surgical ICU patients were collected prospectively. Metabolites were determined using mass spectrometry/ultra‐high‐pressure liquid chromatography and analyzed in patients with delirium and a group of controls matched on age, sex, and admission Sequential Organ Function Assessment (SOFA) score.ResultsPatients in the study (65 per group) were a mean age of 59 years, had a median SOFA score of 6, and were most commonly admitted to the ICU following major trauma. In the delirium group, median onset of delirium was 3 (interquartile range 1–6) days, and the most common delirium subtype was mixed (56%). Kynurenic acid was significantly increased, and tryptophan concentration was significantly decreased in the delirium group (p=0.04). The ratio of kynurenine‐to‐tryptophan concentration was significantly higher in the delirium group (p=0.005).ConclusionsEvidence of upregulation was found in the tryptophan metabolic pathway in delirious patients because tryptophan concentrations were lower, tryptophan metabolites were higher, and the kynurenine‐to‐tryptophan ratio was increased. These findings suggest a role of increased inflammation and accumulation of neurotoxic metabolites in the pathogenesis of ICU delirium. Future studies should target this pathway to validate metabolites in the tryptophan pathway as risk biomarkers in patients with ICU delirium.
Initial teacher education and trauma and violence informed care in the classroom: Preliminary results from an online teacher education course
Authors: Rodger Susan , Bird Richelle , Hibbert Kathryn , Johnson Andrew M. , Specht Jacqueline , Wathen C. Nadine 
Published: April 2020

AbstractA trauma‐and‐violence‐informed‐care (TVIC) system within an educational setting provides a framework of practice that enables schools to become safe and inclusive places for some of the most vulnerable students. Initial teacher education may provide the opportunity to prepare teachers to create classrooms and learning experiences that are safe, equitable, and meet students' needs. A mandatory mental health literacy course for second year teacher candidates in a Bachelor of Education program (n = 287) at a large Canadian university introduced TVIC concepts. A case study approach was used to illustrate both the challenges that students exposed to trauma and/or violence can experience, as well as strategies and knowledge that teachers can use to support these students. This program evaluation used a repeated measures design to survey both attitudes toward trauma informed care for teachers and self‐efficacy for teaching using inclusive practices before and after the course. A significant effect of time on both measures revealed an increase in both participants' attitudes toward TVIC and their self‐efficacy in using inclusive teaching practices. These findings provide support for the inclusion of these important topics for all teacher candidates. Implications for practice and policy are discussed.
Preparation and characterization of a novel controlled‐release nano‐delivery system loaded with pyraclostrobin via high‐pressure homogenization
Authors: Wang Anqi , Cui Jianxia , Wang Yan , Zhu Huaxin , Li Ningjun , Wang Chunxin , Shen Yue , Liu Pengfei , Cui Bo , Sun Changjiao , Zhao Xiang , Wang Chong , Gao Fei , Zeng Zhanghua , Cui Haixin 
Published: April 2020

AbstractBACKGROUNDThe development of efficient and safe green pesticides is a scientific strategy to alleviate current pesticide residues, environmental pollution, and threats to non‐target organisms. Pesticide controlled‐release formulations (CRFs) have attracted wide attention because they can control the rate of release of active ingredients and prolong the effective duration. In particular, nanoscale pesticide sustained‐release systems have excellent biological activity and distribution performance because of their small particle size. Some technical difficulties remain in obtaining nanoscale CRFs.RESULTSWe successfully fabricated pyraclostrobin nanosphere CRF by combining high‐pressure homogenization technology and emulsion–solvent evaporation methods. The pyraclostrobin nanospheres had a uniform spherical shape with a mean particle size of 450 nm and polydispersity index of less than 0.3. The pyraclostrobin loading capacity reached 53.6%, with excellent storage stability. The contact angle of nanospheres on cucumber leaf surfaces demonstrated that it had good wettability. Compared with pyraclostrobin technical and commercial formulations, the nanosphere systems showed a significantly sustained release of pyraclostrobin for longer (up to 250 h). A preliminary bioassay against Penicillium ochrochloron showed that the bioactivity and long‐term efficiency of pyraclostrobin nanospheres were superior to those of the commercial formulation.CONCLUSIONThis research introduced a simple, fast, expandable method for preparing pyraclostrobin nanospheres. The results showed that pyraclostrobin nanospheres could prolong the duration of pesticide efficacy and enhance bioactivity. Furthermore, this technology provides a platform for scale‐up production of nano‐scale pesticide CRFs. © 2020 Society of Chemical Industry
Synthesis of novel 18β‐glycyrrhetinic piperazine amides displaying significant in vitro and in vivo antibacterial activities against intractable plant bacterial diseases
Authors: Xiang Meng , Song Ying‐Lian , Ji Jin , Zhou Xiang , Liu Li‐Wei , Wang Pei‐Yi , Wu Zhi‐Bing , Li Zhong , Yang Song 
Published: April 2020

AbstractBACKGROUNDThe limited amount of agrochemicals targeting plant bacterial diseases has motivated us to study innovative antibacterial surrogates with fresh modes of action. Notably, fabrication of violent apoptosis inducers to control the reproduction of pathogenic bacteria should be a feasible way to control plant bacterial diseases. To achieve this aim, we constructed a series of novel 18β‐glycyrrhetinic piperazine amides based on the natural bioactive ingredient 18β‐glycyrrhetinic acid to evaluate the in vitro and in vivo antibacterial activity and induced apoptosis behaviors on tested pathogens.RESULTSScreening results suggested that these designed compounds were extremely bioactive against two notorious pathogens, Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri. This conclusion was highlighted by the biological effects of compounds A3 and B1, affording the related EC50 values of 2.28 and 0.93 μg mL–1. In vivo trials confirmed the prospective application for managing rice bacterial blight disease with control efficiency within 50.57–53.70% at 200 μg mL–1. In particular, target compounds could induce the generation of excessive reactive oxygen species (ROS) in tested pathogens, subsequently leading to a strong apoptotic effect at a very low drug concentration (≤ 10 μg mL–1). This finding was consistent with the observed ROS‐enhanced fluorescent images and morphological changes of pathogens from scanning electron microscopy patterns.CONCLUSIONGiven these features, we anticipate that these novel piperazine‐tailored 18β‐glycyrrhetinic hybrids can provide an perceptible insight for fighting bacterial infections by activation of the apoptosis mechanism.Novel 18β‐glycyrrhetinic piperazine amides were reported to have excellent antibacterial efficacy toward phytopathogens Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri. A possible apoptosis mechanism was proposed from the remarkable apoptotic behaviors triggered by target compounds. © 2020 Society of Chemical Industry
The male‐produced aggregation pheromone of the bean flower thrips Megalurothrips usitatus in China: identification and attraction of conspecifics in the laboratory and field
Authors: Liu Pingping , Qin Zifang , Feng Mingyue , Zhang Liu , Huang Xinzheng , Shi Wangpeng 
Published: April 2020

AbstractBACKGROUNDThrips, Megalurothrips usitatus, usually display aggregation behavior, which is probably mediated by a male‐produced aggregation pheromone. Aggregation pheromones are species‐specific, and can be used to develop commercial lures for monitoring and mass‐trapping of pests. The active components of the aggregation pheromone for four thrips species have been identified. However, the components of M. usitatus‐produced aggregation pheromone are still not clear.RESULTY‐tube olfactometer assays showed that both male and virgin female M. usitatus were significantly attracted to male but not female volatiles. This was additionally supported by electroantennogram (EAG) assays. Coupled gas chromatography‐electroantennogram detection (GC‐EAD) showed that one component of male‐specific odors elicited a significant electrophysiological response. This compound was characterized as (2E,6E)‐farnesyl acetate, which is structurally different from the active components of the aggregation pheromones of other reported thrips species. Electroantennal responses of M. usitatus increased with increasing doses of synthetic (2E,6E)‐farnesyl acetate. Additionally, this compound significantly attracted adults in laboratory behavioral bioassays. Under field conditions, sticky traps with synthetic (2E,6E)‐farnesyl acetate caught 1.5‐7‐fold more M. usitatus than controls, and this effect of the compound at a dose of 60 μg lasted at least 6 days.CONCLUSION(2E,6E)‐Farnesyl acetate was identified as the male‐produced aggregation pheromone of M. usitatus. It could attract this thrips species under laboratory and field conditions, suggesting considerable potential as a commercial application to control M. usitatus populations. © 2020 Society of Chemical Industry
Tropical water vapour in the lower stratosphere and its relationship to tropical/extratropical dynamical processes in ERA5
Authors: Wang Tongmei , Zhang Qiong , Hannachi Abdel , Hirooka Toshihiko , Hegglin Michaela I. 
Published: April 2020

AbstractStratospheric water vapour (SWV), in spite of its low concentration in the stratosphere as compared to the troposphere, contributes significantly to the surface energy budget and can have an influence on the surface climate. This study investigates the dynamical processes that determine SWV on interannual to decadal time‐scales. First, we evaluate two SWV reanalysis products and show that SWV is better represented in a new‐generation reanalysis product, ERA5, than in its predecessor, ERA‐Interim. In particular, it is shown that SWV in ERA5 is highly consistent with observational data obtained from the SPARC Data Initiative Multi‐Instrument Mean (SDI MIM). Second, we investigate the variability of tropical SWV and its relationship to dynamical stratospheric variables. The analyses show that the interannual variability in the tropical lower‐stratospheric water vapour is closely linked to the tropical Quasi‐Biennial Oscillation (QBO). When westerlies occupy the middle stratosphere and easterlies the lower stratosphere, a decrease is observed in lower‐stratospheric water vapour due to a colder tropical tropopause and a QBO‐induced enhanced residual circulation. On decadal time‐scales, the composite analysis of the boreal winter in two typical periods shows that less SWV is related to a warm anomaly in the North Atlantic sea‐surface temperature, which leads to stronger upward propagation of planetary wave activity at high latitudes, a weaker polar vortex and an enhanced residual circulation. The opposite occurs during periods with higher concentrations of
SWV.
Development and validation of a liquid chromatography/tandem mass spectrometry method to quantify metabolites of phthalates, including di‐2‐ethylhexyl terephthalate (DEHTP) and bisphenol A, in human urine
Authors: Frigerio Gianfranco , Campo Laura , Mercadante Rosa , Santos Patricia Martín , Missineo Pasquale , Polledri Elisa , Fustinoni Silvia 
Published: April 2020

RationaleSeveral phthalates and bisphenol A are endocrine‐disrupting chemicals (EDCs). Recently, their use has been partially restricted and less toxic compounds, such as di‐2‐ethylhexyl terephthalate (DEHTP), have been placed on the market. The aim of this work was to develop and validate a method for the simultaneous quantitation of bisphenol A and urinary metabolites of phthalates, including DEHTP.MethodsAn isotopic dilution high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI‐MS/MS) method for the determination of bisphenol A (BPA), monobenzyl phthalate (MBzP), mono‐2‐ethyl‐5‐carboxypentyl phthalate (MECPP), mono‐2‐ethyl‐5‐carboxypentyl terephthalate (MECPTP), mono‐2‐ethyl‐5‐hydroxyhexyl terephthalate (MEHHTP), monoethyl phthalate (MEP), and mono‐n/i‐butyl phthalates (MnBP/MiBP) in human urine was developed. A complete validation was carried out and the method was applied to 36 non‐occupationally exposed adults.ResultsLimits of quantitation ranged from 0.02 (MECPP) to 1 μg/L (MnBP and MiBP). Relative standard deviations below 10% indicated a suitable precision; accuracy, evaluated using a standard reference material, ranged from 74.3% to 117.5%; isotopically labelled internal standards were suitable for correcting the matrix effect. The accuracy was confirmed by the successful participation in an external verification exercise. However, for terephthalates, the validation was incomplete due to the lack of reference materials and external verification. Levels of the investigated chemicals in subjects were in line with those previously reported.ConclusionsAn LC/MS/MS assay for the simultaneous measurement of BPA and phthalate metabolites in human urine was developed and validated; it is useful to investigate exposure in epidemiological studies involving the general population.
Impurity identification and quantification for arginine vasopressin by liquid chromatography/high‐resolution mass spectrometry
Authors: Wu Peize , Ye Sijian , Li Ming , Li Hongmei , Kan Ying , Yang Zecheng 
Published: April 2020

RationaleFor pharmaceutical quality control, impurities may have unexpected pharmacological or toxicological effects on quality, safety, and efficacy of drugs. Arginine vasopressin (AVP) is an important cyclic peptide drug that is mainly used for the treatment of diabetes insipidus and esophageal varices bleeding. With the advancement made in analytical techniques, liquid chromatography/high‐resolution mass spectrometry (LC/HRMS) has emerged as a critical technique for the identification and quantification of structurally related peptide impurities in AVP.MethodsAn LC/HRMS/MS‐based method using a quadrupole ion trap–Orbitrap mass spectrometer operated in the positive ion electrospray ionization mode was developed for the determination and quantification of structurally related peptide impurities in AVP.ResultsUnder optimized experimental conditions, three deamidation products, ([Glu4]AVP, [Asp5]AVP, and AVP acid), two amino acid deletion impurities (des‐Pro7‐AVP and des‐Gly9‐AVP), one amino acid insertion impurity (endo‐Gly10a‐AVP), one end chain reaction product (N‐acetyl‐AVP), and one AVP isomer were detected. Subsequent quantification using an external standard method estimated the total mass fraction of all structurally related peptide impurities in the AVP study material to be 30.3 mg/g with an expanded uncertainty of 3.0 mg/g (k = 2).ConclusionsThis study complements the AVP impurity profile and improves the separation and discovery of other potential impurities in vasopressin analogues.
Chemical compositional analysis of soil fulvic acids using Fourier transform ion cyclotron resonance mass spectrometry
Authors: Ikeya Kosuke , Sleighter Rachel L. , Hatcher Patrick G. , Watanabe Akira 
Published: April 2020

RationaleSoil fulvic acids (FAs) are considered to be a highly reactive pool of soil organic matter. The functions of FAs are related to their chemical structures, the details of which are largely unidentified. To better understand them, Fourier transform ion cyclotron resonance mass spectrometry (FTICR‐MS) must be a useful but generally unused tool.MethodsThe structural properties of the components of five FA samples from a variety of soils were determined using FTICR‐MS with negative‐mode electrospray ionization. The peaks were assigned to molecular formulae, which were categorized into seven compound groups based on the H/C–O/C van Krevelen diagram. Ramp 13C cross polarization/magic angle spinning nuclear magnetic resonance (NMR) spectra with phase‐adjusted spinning side bands were also recorded to estimate the C composition.ResultsFrom FTICR‐MS, molecular formulae were assigned to 1746–2605 peaks across the m/z range of 200–700. Those aligned in the lignin‐like, tannin‐like, and condensed aromatic regions of the van Krevelen diagram accounted for 49–58%, 4–20%, and 18–39% of the total peak magnitude, respectively. The proportion of the summed peak magnitudes that were detected in the lignin‐like and condensed aromatic regions correlated positively to the aromatic C% as estimated by 13C NMR. From Kendrick mass defect analysis using a carboxyl group, 94 molecular formulae were assigned to condensed aromatic acids, of which the maximum ring number was 4–7, as potential structures.ConclusionsA high proportion of lignin‐like formulae and condensed aromatics, including those probably condensed aromatic acids with small ring numbers, as well as the existence of tannin‐like formulae, which were generally lacking in soil humic acids, was suggested as a common feature of soil FAs.
UV post‐ionization laser ablation ionization mass spectrometry for improved nm‐depth profiling resolution on Cr/Ni reference standard
Authors: Grimaudo Valentine , Tulej Marek , Riedo Andreas , Lukmanov Rustam , Ligterink Niels F.W. , de Koning Coenraad , Wurz Peter 
Published: April 2020

RationaleLaser ablation combined with mass spectrometry forms a promising tool for chemical depth profiling of solids. At irradiations near the ablation threshold, high depth resolutions are achieved. However, at these conditions, a large fraction of ablated species is neutral and therefore invisible to the instrument. To compensate for this effect, an additional ionization step can be introduced.MethodsDouble‐pulse laser ablation is frequently used in material sciences to produce shallow craters. We apply double‐pulse UV femtosecond (fs) Laser Ablation Ionization Mass Spectrometry to investigate the depth profiling performance. The first pulse energy is set to gentle ablation conditions, whereas the second pulse is applied at a delay and a pulse energy promoting the highest possible ion yield.ResultsThe experiments were performed on a Cr/Ni multi‐layered standard. For a mean ablation rate of ~3 nm/pulse (~72 nJ/pulse), a delay of ~73 ps provided optimal results. By further increasing the energy of the second pulse (5–30% higher with respect to the first pulse) an enhancement of up to 15 times the single pulse intensity was achieved. These conditions resulted in mean depth resolutions of ~37 and ~30 nm for the Cr and Ni layers, respectively.ConclusionsIt is demonstrated on the thin‐film standard that the double‐pulse excitation scheme substantially enhances the chemical depth profiling resolution of LIMS with respect to the single‐pulse scheme. The post‐ionization allows for extraordinarily low ablation rates and for quantitative and stoichiometric analysis of nm‐thick films/coatings.