bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion and wear resistance properties of multilayered diamond‐like carbon nanocomposite coating
Authors: Viswanathan S. , Mohan L. , Bera Parthasarathi , Shanthiswaroop S. , Muniprakash M. , Barshilia Harish C. , Anandan C.
Published: January 2018

Multilayered diamond‐like carbon (DLC) nanocomposite coating has been deposited on silicon and stainless steel substrates by combination of cathodic arc evaporation and magnetron sputtering. In order to make DLC coating adhered to metal substrate, a chromium interlayer has been deposited with constant bias voltage of −150 V applied to the substrate. Dense multilayered coating consists of metallic or nonmetallic and tetrahedral carbon (ta‐C) layers with total thickness of 1.44 μm. The coating has been studied for composition, morphology, surface nature, nanohardness, corrosion resistance, and tribological properties. The composition of the coating has been estimated by energy‐dispersive spectroscopy. Field‐emission scanning electron microscopy and atomic force microscopy have been used to study the surface morphology and topography. ID/IG ratio of ta‐C:N layer obtained from Raman spectroscopy is 1.2, indicating the disorder in the layer. X‐ray photoelectron spectroscopy studies of individual ta‐C:N, CrN, and Cr‐doped DLC layers confirm the presence of sp2C, sp3C, CrN, Cr2N, and carbidic carbon, and sp2C, sp3C, and Cr carbide. Nanohardness studies show the maximum penetration depth of 70 to 85 nm. Average nanohardness of the multilayered DLC coating is found to be 35 ± 2.8 GPa, and Young's modulus is 270 GPa. The coating demonstrates superior corrosion resistance with better passivation behavior in 3.5% NaCl solution, and corrosion potential is observed to move towards nobler (more positive) values. A low coefficient of friction (0.11) at different loads is observed from reciprocating wear studies. Wear volume is lower at all loads on the multilayered DLC nanocomposite coating compared to the substrate.
P‐GaSe/N‐MoS2 Vertical Heterostructures Synthesized by van der Waals Epitaxy for Photoresponse Modulation
Authors: Zhou Nan , Wang Renyan , Zhou Xing , Song Hongyue , Xiong Xing , Ding Yao , Lü Jingtao , Gan Lin , Zhai Tianyou
Published: January 2018

The important role of p–n junction in modulation of the optoelectronic properties of semiconductors is widely cognized. In this work, for the first time the synthesis of p‐GaSe/n‐MoS2 heterostructures via van der Waals expitaxial growth is reported, although a considerable lattice mismatching of ≈18% exists. According to the simulation, a significant type II p–n junction barrier located at the interface is expected to be formed, which can modulate optoelectronic properties of MoS2 effectively. It is intriguing to reveal that the presence of GaSe can result in obvious Raman and photoluminescence (PL) shift of MoS2 compared to that of pristine one, more interestingly, for PL peak shift, the effect of GaSe‐induced tensile strain on MoS2 has overcome the p‐doping effect of GaSe, evidencing the strong interlayer coupling between GaSe and MoS2. As a result, the photoresponse rate of heterostructures is improved by almost three orders of magnitude compared with that of pristine MoS2.
Freeze the Moment: High Speed Capturing of Weakly Bonded Dynamic Nanoparticle Assemblies in Solution by Ag Ion Soldering
Authors: Wang Yueliang , Fang Lingling , Chen Gaoli , Song Lei , Deng Zhaoxiang
Published: January 2018

Despite the versatile forms of colloidal aggregates, these spontaneously formed structures are often hard to find a suitable application in nanotechnology and materials science. A determinate reason is the lack of a suitable method to capture the transiently formed and quickly evolving colloidal structures in solution. To address this challenge, a simple but highly efficient strategy is herein reported to capture the dynamic and metastable colloidal assemblies formed in an aqueous or nonaqueous solution. This process takes advantage of a recently developed Ag ion soldering reaction to realize a rapid fixation of as‐formed metastable assemblies. This method works efficiently for both solid (3D) nanoparticle aggregates and weakly bonded fractal nanoparticle chains (1D). In both cases, very high capturing speed and close to 100% efficiency are achieved to fully retain a quickly growing structure. The soldered nanochains further enable a fabrication of discrete, uniform, and functionalizable nanoparticle clusters with enriched linear conformation by mechanical shearing, which would otherwise be difficult to make. The captured products are water dispersible and mechanically robust, favoring an exploration of their properties toward possible applications. The work paves a way to previously untouched aspects of colloidal science and thus would create new chances in nanotechnology.
Molybdenum Sulphoselenophosphide Spheroids as an Effective Catalyst for Hydrogen Evolution Reaction
Authors: Bose Ranjith , Jothi Vasanth Rajendiran , Koh Beomsoo , Jung Chiyoung , Yi Sung Chul
Published: January 2018

Electrocatalytic splitting of water is the most convincing and straight forward path to extract hydrogen, but the efficiency of this process relies heavily on the catalyst employed. Here, molybdenum sulphoselenophosphide (MoS45.1Se11.7P6.1) spheroids are reported as an active catalyst for the hydrogen evolution reaction (HER) and this is the first attempt to study on ternary anion based molybdenum chalcogenides. As‐prepared MoSxSeyPz catalyst reveals a unique morphology of microspheroids capped by stretched‐out nanoflakes that exhibits excellent electrocatalytic activity (   j—10 mA cm−2 @ 93 mV, Tafel slope of 50.1 mV dec−1, TOF—0.40 s−1) fairly closer to the performance of platinum (Pt) and predominant to those of the pre‐existing Mo‐chalcogenides and phosphides. Such an increase in performance stems from the copious amount of active edge sites, the presence of nanoflakes, and high circumferential area exposed by the spheroids. Besides, the electrode with MoS45.1Se11.7P6.1 displays excellent stability in acidic medium over 10 h of continuous operation. This work paves way for improving the catalytic activity of existing Mo‐chalcogenide compounds by doping suitable mixed anions and also reveals the integral role of anions as well as their synergetic effects on the surface physiochemical properties and the HER catalysis.
Interactive effects of hypoxia and PCB co‐exposure on expression of CYP1A and its potential regulators in Atlantic croaker liver
Authors: Rahman Md Saydur , Thomas Peter
Published: January 2018

Although marine and coastal environments which are contaminated with xenobiotic organic compounds often become hypoxic during the summer, the interactive effects of hypoxia and xenobiotic exposure on marine species such as teleost fishes remain poorly understood. The expression and activity of monooxygenase enzyme cytochrome P450‐1A (CYP1A) in fishes are upregulated by exposure to polychlorinated biphenyls (PCBs), whereas they are down‐regulated during hypoxia exposure. We investigated the interactive effects of hypoxia and PCB co‐exposure on hepatic CYP1A expression in Atlantic croaker and on potential regulators of CYP1A. Croaker were exposed to hypoxia (1.7 mg/L dissolved oxygen), 3,3′,4,4′‐tetrachlorobiphenyl (PCB 77, dose: 2 and 8 µg/g body weight), and Aroclor 1254 (a common PCB mixture, dose: 0.5 and 1 µg/g body weight), alone and in combination for 4 weeks. PCB 77 exposure markedly increased hepatic CYP1A mRNA and protein expression, and ethoxyresorufin‐O‐deethylase (EROD, an indicator of CYP1A enzyme) activity and increased endothelial nitric oxide synthase (eNOS) protein expression. PCB 77 treatment also increased interleukin‐1β (IL‐1β, a cytokine) mRNA levels and protein carbonyl (PC, an indicator of reactive oxygen species, ROS) contents. These marked PCB 77‐ and Aroclor 1254‐induced increases in CYP1A mRNA levels and EROD activity were significantly attenuated by co‐exposure to hypoxia, whereas the increases in hepatic eNOS protein and IL‐1β mRNA expression, and PC contents were augmented by hypoxia co‐exposure. The results suggest that biotransformation of organic xenobiotics by CYP1A is reduced in fish during co‐exposure to hypoxia and is accompanied by alterations in eNOS, ROS, and IL‐1β levels.
Liquid futures: Water management systems and anticipated environments
Authors: Randle Sayd , Barnes Jessica
Published: January 2018

Climate change and its impact on hydrological dynamics have become key topics of concern among water managers and policy makers in many parts of the world. Yet while practitioners often frame adaptation to a climate‐changed future as a novel issue, ideas about future environments have long influenced systems of water management. Reviewing ethnographic and historical accounts of waterscapes across the globe, this article examines the relationship between imagined environmental futures and the policies, practices, infrastructures of water management and legal frameworks. We show, first, how conflicting ideas about environmental stasis and perturbation have been built into water networks across space and time. In some cases, notions of radical landscape change have underpinned these systems, as in programs dedicated to land “reclamation” or interbasin water transfer schemes. In other contexts, water systems have developed based on visions of long‐term sociohydrological stability. Second, we highlight how contrasting notions of human capacity to change environmental outcomes have played into water management systems. In some cases, there has been an assumption of the potential for and desirability of full human control; in others, there has been more recognition of the limits of such mastery. Exploring the wide range of environmental imaginaries mobilized through water management, we contextualize contemporary efforts to build resilient, “climate proof” waterscapes. WIREs Water 2018, 5:e1274. doi: 10.1002/wat2.1274

This article is categorized under:

Human Water > Water as Imagined and Represented

Science of Water > Water Quality
Compiling lightning counts for the UK land area and an assessment of the lightning risk facing UK inhabitants
Authors: Elsom Derek M. , Enno Sven‐Erik , Horseman Andrew , Webb Jonathan D. C.
Published: January 2018

New estimates of lightning counts from the Met Office ATDnet system are obtained for the ‘UK land area’ and compared with those currently available for the ‘UK service area’ (which includes Republic of Ireland and surrounding seas). Annual counts average 38% of those in the ‘UK service area’. Case studies of thundery periods highlight daily differences. The new annual counts offer a more accurate estimate of the lightning risk facing the UK population. For the period 2008–2016, one lightning death occurred, on average, per 59 000 lightning counts, and one person was either killed or injured per 4000–5000 counts.
Human microbiota, blood group antigens, and disease
Authors: Ewald D. Rose , Sumner Susan C.J.
Published: January 2018

Far from being just “bugs in our guts,” the microbiota interacts with the body in previously unimagined ways. Research into the genome and the microbiome has revealed that the human body and the microbiota have a long‐established but only recently recognized symbiotic relationship; homeostatic balance between them regulates body function. That balance is fragile, easily disturbed, and plays a fundamental role in human health—our very survival depends on the healthy functioning of these microorganisms. Increasing rates of cardiovascular, autoimmune, and inflammatory diseases, as well as epidemics in obesity and diabetes in recent decades are believed to be explained, in part, by unintended effects on the microbiota from vaccinations, poor diets, environmental chemicals, indiscriminate antibiotic use, and “germophobia.” Discovery and exploration of the brain‐gut‐microbiota axis have provided new insights into functional diseases of the gut, autoimmune and stress‐related disorders, and the role of probiotics in treating certain affective disorders; it may even explain some aspects of autism. Research into dietary effects on the human gut microbiota led to its classification into three proposed enterotypes, but also revealed the surprising role of blood group antigens in shaping those populations. Blood group antigens have previously been associated with disease risks; their subsequent association with the microbiota may reveal mechanisms that lead to development of nutritional interventions and improved treatment modalities. Further exploration of associations between specific enteric microbes and specific metabolites will foster new dietary interventions, treatment modalities, and genetic therapies, and inevitably, their application in personalized healthcare strategies.

This article is categorized under:

Laboratory Methods and Technologies > Metabolomics

Translational, Genomic, and Systems Medicine > Translational Medicine

Physiology > Mammalian Physiology in Health and Disease
Online Patient Ratings Are Not Correlated with Total Knee Replacement Surgeon–Specific Outcomes
Authors: Trehan Samir K. , Nguyen Joseph T. , Marx Robert , Cross Michael B. , Pan Ting J. , Daluiski Aaron , Lyman Stephen
Published: January 2018

Background

Despite potential concerns regarding their validity, physician-rating websites continue to grow in number and utilization and feature prominently on major search engines, potentially affecting patient decision-making regarding physician selection.

Questions/Purposes

We sought to determine whether patient ratings on public physician-rating websites correlate with surgeon-specific outcomes for high-volume total knee replacement (TKR) surgeons in New York State (NYS) from 2010 to 2012.

Methods

Online patient ratings were compared to surgeon-specific outcomes from the Statewide Planning and Research Cooperative System (SPARCS) database from the NYS Department of Health. For each surgeon, we determined the infection rate, re-admission rate, and revision surgery rate within the study period, as well as the mean inpatient length of stay, for TKR from the SPARCS database. Online ratings were collected from two physician-rating websites ( Vitals.com and HealthGrades.com ).

Results

One hundred seventy-four high-volume TKR surgeons were identified in NYS from 2010 to 2012. The mean rates of in-hospital infection, 90-day infection, 30-day re-admission, 90-day re-admission, and revision surgery were 0.25, 1.00, 4.89, 8.43, and 1.31%, respectively. The mean number of ratings for individual surgeons on HealthGrades.com and Vitals.com were 24.0 (range: 0 to 109) and 19.3 (range: 0 to 114), respectively, and mean overall ratings were 4.2 and 4.1 (out of 5) stars, respectively. As with online patient ratings of individual surgeons, variability was observed in the total adverse event rate distribution for individual surgeons. Despite sufficient variability in both online patient rating and surgeon-specific outcomes for high-volume TKR surgeons in NYS, no correlation was observed.

Conclusion

There was no correlation between surgeon-specific TKR outcome measures and online patient ratings. We therefore advise that patients exert caution when interpreting ratings on these websites.
Genetik der kortikalen Fehlbildungen
Authors: Di Donato Nataliya
Published: January 2018

Kortikale Malformationen sind vielfältig und stellen eine wichtige Ursache der geistigen Entwicklungsstörung und der Epilepsie dar. Die Ätiologie der kortikalen Fehlbildungen ist sehr heterogen und beinhaltet sowohl rein exogene Ursachen als auch chromosomale und monogene Erkrankungen. Eine effiziente genetische Diagnostik bedarf der akkuraten Interpretation des Magnetresonanztomographie(MRT)-Musters. Bei einigen klinischen Formen kann eine zielgerichtete Einzelgendiagnostik erfolgen, die anderen klinischen Entitäten erfordern dagegen eine komplexe Stufendiagnostik und können nur mittels Hochdurchsatzsequenzierung aufgeklärt werden. In diesem Beitrag werden die 4 häufigsten kortikalen Fehlbildungen im Hinblick auf die typischen klinischen Symptome, MRT-Merkmale und den Algorithmus der genetischen Abklärung vorgestellt.
Divorce, Separation, and Housing Changes: A Multiprocess Analysis of Longitudinal Data from England and Wales
Authors: Mikolai Júlia , Kulu Hill
Published: January 2018

This study investigates the effect of marital and nonmarital separation on individuals’ residential and housing trajectories. Using rich data from the British Household Panel Survey (BHPS) and applying multilevel competing-risks event history models, we analyze the risk of a move of single, married, cohabiting, and separated men and women to different housing types. We distinguish moves due to separation from moves of separated people and account for unobserved codeterminants of moving and separation risks. Our analysis shows that many individuals move due to separation, as expected, but that the likelihood of moving is also relatively high among separated individuals. We find that separation has a long-term effect on individuals’ residential careers. Separated women exhibit high moving risks regardless of whether they moved out of the joint home upon separation, whereas separated men who did not move out upon separation are less likely to move. Interestingly, separated women are most likely to move to terraced houses, whereas separated men are equally likely to move to flats (apartments) and terraced (row) houses, suggesting that family structure shapes moving patterns of separated individuals.
Variation of genes involved in oxidative and nitrosative stresses in depression
Authors: Wigner Paulina , Czarny Piotr , Synowiec Ewelina , Bijak Micha� , Białek Katarzyna , Talarowska Monika , Galecki Piotr , Szemraj Janusz , Sliwinski Tomasz
Published: January 2018

The dominating hypothesis among numerous hypotheses explaining the pathogenesis of depressive disorders (DD) is the one involving oxidative and nitrosative stress. In this study, we examined the association between single-nucleotide polymorphisms of the genes encoding SOD2 (superoxide dismutase 2), CAT (catalase), GPx4 (glutathione peroxidase 4), NOS1 (nitric oxide synthase 1), NOS2 (nitric oxide synthase 2), and the development of depressive disorders. Our study was carried out on the DNA isolated from peripheral blood collected from 281 depressed patients and 229 controls. Using TaqMan probes, we genotyped the following six polymorphisms: c.47T > C (p.Val16Ala) (rs4880) in SOD2, c.-89A > T (rs7943316) in CAT, c.660T > C (rs713041) in GPx4, c.-420-34221G > A (rs1879417) in NOS1, c.1823C > T (p.Ser608Leu) (rs2297518), and c.-227G > C (rs10459953) in NOS2. We found that the T/T genotype of the c.47T > C polymorphism was linked with an increased risk of depression. Moreover, the T/T genotype and T allele of c.660T > C increased the risk of DD occurrence, while the heterozygote and C allele decreased this risk. On the other hand, we discovered that the A/A genotype of c.-89A > T SNP was associated with a reduced risk of DD, while the A/T genotype increased this risk. We did not find any correlation between the genotypes/alleles of c.-420-34221G > A, c.1823C > T, and c.-227G > C, and the occurrence of DD. In addition, gene-gene and haplotype analyses revealed that combined genotypes and haplotypes were connected with the disease. Moreover, we found that sex influenced the impact of some SNPs on the risk of depression. Concluding, the studied polymorphisms of SOD2, CAT and GPx4 may modulate the risk of depression. These results support the hypothesis that oxidative and nitrosative stresses are involved in the pathogenesis of depressive disorders.
The case for laboratory experiments in behavioural public policy
Authors: LUNN PETER D. , NÍ CHOISDEALBHA ÁINE
Published: January 2018

Behavioural science is increasingly applied to policy in many countries. While the empirical approach to policy development is welcome, we argue with reference to existing literature that laboratory experiments are presently underused in this domain, relative to field studies. Assumptions that field experiments, including randomised controlled trials, produce more generalisable results than laboratory experiments are often misplaced. This is because the experimental control offered by the laboratory allows underlying psychological mechanisms to be isolated and tested. We use examples from recent research on energy efficiency and financial decision-making to argue that mechanism-focused laboratory research is often not only complementary to field research, but also necessary to interpreting field results, and that such research can have direct policy implications. The issues discussed illustrate that in some policy contexts a well-designed laboratory study can be a good – perhaps the best – way to answer the kinds of research questions that policy-makers ask.
Enrolee outcomes after health insurance plan terminations: a diagnosis of default effects
Authors: SINAIKO ANNA D. , ZECKHAUSER RICHARD
Published: January 2018

Behavioural economic research has established that defaults, one form of nudge, powerfully influence choices. In most policy contexts, all individuals receive the same nudge. We present a model that analyses the optimal universal nudge for a situation in which individuals differ in their preferences and hence should make different choices and may incur a cost for resisting a nudge. Our empirical focus is onterminated choosers(TCs), individuals whose prior choices become no longer available. Specifically, we examine the power of defaults on individuals who had enrolled in Medicare Advantage plans with drug coverage and whose plans were then discontinued. Currently, if these TCs fail to actively choose another Medicare Advantage plan, they are defaulted into traditional fee-for-service Medicare (TM) without drug coverage. Overall, the rate of transition of TCs into TM is low, implying that original preferences and status quo bias overpower the default. Increasing numbers of Americans are choosing plans in health insurance exchange settings such as Medicare, the Affordable Care Act and private exchanges. Plan exits and large numbers of TCs are inevitable, along with other forms of turmoil. Any guidance and defaults provided for TCs should factor in their past revealed preferences.
Towards turbulent times: measuring and explaining party system (de-)institutionalization in Western Europe (1945–2015)
Authors: Chiaramonte Alessandro , Emanuele Vincenzo
Published: January 2018

Over the last decades, Western European party systems have experienced growing levels of electoral volatility and the recurring emergence of successful new parties. This evidence calls into question the issue of party system institutionalization (PSI), a topic taken for granted so far in Western Europe, following the conventional wisdom that party systems are highly institutionalized in this region. This article tackles this issue and provides some contributions: it offers a theoretical clarification of PSI and develops an index allowing for cross-country and cross-time comparability; it looks for an explanation, by testing the impact of various potential determinants and their changes over time. Covering 324 elections in 19 countries since 1945, the analysis shows that, since the 1970s, a process of de-institutionalization is going on and that PSI is mainly a function of the cleavage structure and the number of parties, with economic performance becoming relevant only in the last period.
Third-Party Actors and the Intentional Targeting of Civilians in War
Authors: Appel Benjamin J. , Prorok Alyssa K.
Published: January 2018

This article examines the relationship between third-party actors and the intentional targeting of non-combatants in interstate war. It argues that war participants kill fewer civilians in war when their expectation of third-party punishment is high. Combatants will anticipate a high likelihood of third-party sanctions when their alliance and trade networks are dominated by third parties that have ratified international treaties prohibiting the intentional targeting of non-combatants. The study hypothesizes that war combatants kill fewer civilians in war as the strength of ratifiers within their alliance and trade networks increases. Quantitative tests on a dataset of all interstate wars from 1900–2003 provide strong statistical and substantive support for this hypothesis.
Between Rio’s Red-Light District and the League of Nations: Immigrants and Sex Work in 1920s Rio de Janeiro
Authors: Schettini Cristiana
Published: January 2018

This article focuses on sex work relations in the Mangue, one of Rio de Janeiro’s red light districts in the 1920s. It follows multiple simultaneous trajectories that converge in Rio’s changing urban landscape: League of Nation’s investigators (some of them undercover), local Brazilian authorities, particularly the police, and Fanny Galper, a former prostitute and madam. It argues that the spatial mobility of the persons involved in sex work is part of broader debates: On the one hand, these experiences of mobility are closely connected to the variegated attempts at surveillance of sex work that characterized Rio de Janeiro in the 1920s and the specific racialized organization of the women’s work as prostitutes. On the other hand, the actors analysed in this article also participated, in different ways, in the production of meanings in broader debates on the international circulation of policies intended to regulate and surveil prostitution. These encounters offer the opportunity to explore some of the intersections between this international circulation of policies, local social dynamics of European immigration, and the racialized history of labor relations in Brazil.
From the Gorbals to the Lower East Side: the Cosmopolitanism of the Glasgow Jewish Institute Players
Authors: Maloney Paul , Scullion Adrienne
Published: January 2018

In this essay Paul Maloney and Adrienne Scullion investigate the ambitious agenda of theatre internationalism in the context of non-professional theatre making in Glasgow in the mid-twentieth century. For members of the Glasgow Jewish Institute Players, internationalism was represented through a diverse repertoire of classic European texts and contemporary American plays, presented alongside new original plays and sketches drawing on Yiddish and Scottish popular theatre tropes, and experienced through its members’ range of international diasporic networks, specifically with Jewish theatre makers in New York. It is argued that the internationalizing experience of the company and, specifically, its sustained exploration of immigration and of immigrants, achieves an important, even defining, role in the formation of a modern theatre industry and identity in Scotland. Historically interesting in and of itself, this article is also timely given a wider social and cultural ‘fear’ of contemporary migrants. The research encompasses a range of previously unexplored primary material including scripts, reviews, photographs, and company papers, including correspondence with New York-based playwright Sylvia Regan and new interviews with surviving company members. Paul Maloney and Adrienne Scullion work at Queen's University Belfast.
Body and Communication: The ‘Ordinary’ Art of Tang Da Wu
Authors: WEE C. J. W.-L.
Published: January 2018

What might the contemporary performing body look like when it seeks to communicate and to cultivate the need to live well within the natural environment, whether the context of that living well is framed and set upon either by long-standing cultural traditions or by diverse modernizing forces over time? The Singapore performance and visual artist Tang Da Wu has engaged with a present and a region fractured by the predations of unacceptable cultural norms – the consequences of colonial modernity or the modern nation state taking on imperial pretensions – and the subsumption of Singapore society under capitalist modernization. Tang's performing body both refuses the diminution of time to the present, as is the wont of the forces he engages with, and undertakes interventions by sometimes elusive and ironic means – unlike some overdetermined contemporary performance art – that reject the image of the modernist ‘artist as hero’. Part of the cause for this distinctive art committed to historicity and a deliberate ordinariness is that artistic communication to him means provoking self-reflexive thought rather than immediate action. Over the years this has resulted in collaborative artistic workshops, in which he has imaginatively transferred art making from his body to the realm of ordinary people. These workshops become his particular extension of the neo-avant-garde's breaching of art's infrastructures.
Video-Based Learning vs Traditional Lecture for Instructing Emergency Medicine Residents in Disaster Medicine Principles of Mass Triage, Decontamination, and Personal Protective Equipment
Authors: Curtis Henry A. , Trang Karen , Chason Kevin W. , Biddinger Paul D.
Published: January 2018

Introduction

Great demands have been placed on disaster medicine educators. There is a need to develop innovative methods to educate Emergency Physicians in the ever-expanding body of disaster medicine knowledge. The authors sought to demonstrate that video-based learning (VBL) could be a promising alternative to traditional learning methods for teaching disaster medicine core competencies.

Hypothesis/Problem

The objective was to compare VBL to traditional lecture (TL) for instructing Emergency Medicine residents in the American College of Emergency Physicians (ACEP; Irving, Texas USA) disaster medicine core competencies of patient triage and decontamination.

Methods

A randomized, controlled pilot study compared two methods of instruction for mass triage, decontamination, and personal protective equipment (PPE). Emergency Medicine resident learning was measured with a knowledge quiz, a Likert scale measuring comfort, and a practical exercise. An independent samples t-test compared the scoring of the VBL with the TL group.

Results

Twenty-six residents were randomized to VBL (n=13) or TL (n=13). Knowledge score improvement following video (14.9%) versus lecture (14.1%) did not differ significantly between the groups (P=.74). Comfort score improvement also did not differ (P=.64) between video (18.3%) and lecture groups (15.8%). In the practical skills assessment, the VBL group outperformed the TL group overall (70.4% vs 55.5%; P<.0001), with significantly better performance in donning PPE and decontamination. Although not part of the original study design, a three-month post-hoc analysis was performed. When comparing the pre-intervention and three-month post-hoc performances, there were no significant differences in knowledge increases between VBL versus TL (P=.41) or in comfort (P=.39).

Conclusion

Video modules can be as effective as TL when utilized to train Emergency Medicine residents in the ACEP disaster medicine core competencies of patient triage and decontamination.

CurtisHA, TrangK, ChasonKW, BiddingerPD. Video-based learning vs traditional lecture for instructing emergency medicine residents in disaster medicine principles of mass triage, decontamination, and personal protective equipment. Prehosp Disaster Med. 2018;33(1):7–12.
Dosimetric evaluation of a novel electron–photon mixed beam, produced by a medical linear accelerator
Authors: Khaledi Navid , Sardari Dariush , Mohammadi Mohammad , Ameri Ahmad , Reynaert Nick
Published: January 2018

Aim

This study deals with the characteristics of simultaneous photon and electron beams in homogenous and inhomogeneous phantoms by experimental and Monte Carlo dosimetry, for therapeutic purposes. Materials and methods: Both 16 and 20 MeV high-energy electron beams were used as the original beam to strike perforated lead sheets to produce the mixed beam. The dosimetry results were achieved by measurement in an ion chamber in a water phantom and film dosimetry in a Perspex nasal phantom, and then compared with those calculated through a simulation approach. To evaluate two-dimensional dose distribution in the inhomogeneous medium, the dose–area histogram was obtained.

Results

The highest percentage of photon contribution in mixed beam was found to be 36% for 2-mm thickness of lead layer with holes diameter of 0·2 cm for a 20 MeV primary electron energy. For small fields, the percentage depth dose parameters variations were found to be similar to pure electron beam within ±2%. The most feasible flatness in beam profile was 11% for pure electron and 7% for the mixed beam. Penumbra changes as function of depth was about ten times better than in pure electron field.

Conclusions

The results present some dosimetric advantages that can make this study a platform for the production of simultaneous mixed beams in future linear accelerators (LINACs), which through redesign of the LINAC head, which could lead to setup error reduction and a decrease of intra-fractional tumour cells repair.
Honoring Earth and Space Scientists
Authors:   AGU
Published: January 2018

AGU members and others in the news.
Shot-by-shot characterization of focused X-ray free electron laser pulses
Authors: Kobayashi Amane , Sekiguchi Yuki , Oroguchi Tomotaka , Yamamoto Masaki , Nakasako Masayoshi
Published: January 2018

X-ray free electron lasers (XFEL) provide intense and almost coherent X-ray pulses. They are used for various experiments investigating physical and chemical properties in materials and biological science because of their complete coherence, high intensity, and very short pulse width. In XFEL experiments, specimens are irradiated by XFEL pulses focused by mirror optics. The focused pulse is too intense to measure its coherence by placing an X-ray detector on the focal spot. Previously, a method was proposed for evaluating the coherence of focused pulses from the visibility of the diffraction intensity of colloidal particles by the speckle visibility spectroscopy (SVS). However, the visibility cannot be determined exactly because the diffraction intensity is integrated into each finite size detector pixel. Here, we propose a method to evaluate the coherence of each XFEL pulse by using SVS in combination with a theory for exact sampling of the diffraction pattern and a technique of multiplying the diffraction data by a Gaussian masks, which reduces the influence of data missing in small-angle regions due to the presence of a direct beamstop. We also introduce a method for characterizing the shot-by-shot size of each XFEL pulse by analysing the X-ray irradiated area.
A new group of synthetic phenolic-containing amphiphilic molecules for multipurpose applications: Physico-chemical characterization and cell-toxicity study
Authors: Anankanbil Sampson , Pérez Bianca , Fernandes Iva , Widzisz Katarzyna Magdalena , Wang Zegao , Mateus Nuno , Guo Zheng
Published: January 2018

Nine synthetic amphiphilic phenolic lipids, varied in phenolic moiety (caffeoyl/dimethylcaffeoyl) and fatty acid chain lengths (8–18) were characterized by differential scanning calorimetry (DSC), temperature-ramp Fourier transform infra-red spectroscopy (FT-IR) and atomic force microscopy (AFM). FT-IR and DSC results revealed that the physical state and lateral packing of synthetic molecules were largely governed by fatty acyls. The critical micelle concentrations (CMC) of synthetic lipids was in the range of 0.1 mM to 2.5 mM, affording generation of stable oil-in-water emulsions; as evidenced by the creaming index (<5%) of emulsions stabilized by compounds C12‒C16, and C12a‒C16a after 7 days’ storage. AFM analysis revealed that compound C14 formed stable double-layers films of 5.2 nm and 6.7 nm. Application studies showed that formulations stabilized by synthesized compounds containing 30% fish oil had superior physical and oxidative stability compared to formulations containing commercial emulsifiers or their mixtures with phenolic acids. Moreover, the synthetic compounds were non-toxic against in vitro transformed keratinocytes from histologically normal skin and Caco-2 cell lines. This study demonstrates the relevance of using a natural hydroxycarboxylic acid as a flexible linker between natural antioxidants, glycerol and fatty acids to generate multifunctional amphiphiles with potential applications in food, pharmaceutical and cosmetic industry.
Simplest chaotic system with a hyperbolic sine and its applications in DCSK scheme
Authors: Liu Jizhao , Clinton Sprott Julien , Wang Shaonan , Ma Yide
Published: January 2018

This work describes the simplest chaotic system with a hyperbolic sine non‐linearity, accompanied by analysis of Lyapunov exponents, bifurcations, and stability. The corresponding simple chaotic circuit using only diodes and linear components is designed and implemented. Finally, an application of the system to spread spectrum communication based on differential chaos shift keying (DCSK) is presented. Since the hyperbolic sine is an odd function of its argument, the system is antisymmetric and exhibits symmetry breaking where the attractors split or merge as some bifurcation parameter is changed. The proposed system is especially simple both from the structure of the equations and in its electronic circuit realisation. Compared with the traditional DCSK scheme of a Chebyshev sequence, the system can reduce the bit error rate in the presence of noise.
Incremental stability for switched non‐linear systems based on geometrically incremental dissipativity
Authors: Ren Yuanhong , Wang Weiqun , Wang Yixiang
Published: January 2018

In this study, a geometrically incremental dissipativity is proposed for switched discrete‐time non‐linear systems using multiple storage functions and multiple supply rates. The uniform incremental stability conditions are derived for geometrically incrementally dissipative discrete‐time switched systems by using multiple Lyapunov functions approach and average dwell‐time technique. The geometrically incremental dissipativity is preserved for the feedback interconnected switched non‐linear systems with a composite switching law, while uniform incremental stability is preserved under some certain conditions. Two numerical examples are given to illustrate the validity of the authors' results.
Compact dual‐band circularly polarised antenna with omnidirectional and unidirectional properties
Authors: Wang Meng‐Shuang , Zhu Xiao‐Qi , Guo Yong‐Xin , Wu Wen
Published: January 2018

A novel dual‐band circularly polarised (CP) antenna is presented in this study. The proposed antenna is composed of a U‐slot patch and four sequentially rotated shorted monopoles. Different from conventional omnidirectional CP antennas with shorted monopolar patches, a novel capacitively coupled technique is proposed to achieve good impedance matching, which makes it possible to generate unidirectional CP patterns simultaneously. This antenna can generate omnidirectional CP radiation patterns in the global positioning system L1 band (1575 ± 5 MHz) for navigation application and unidirectional CP radiation patterns in the 2.4‐GHz industrial, scientific, and medical band (2.40–2.48 GHz) for municipal wireless networks. The dual‐band performance can be tuned separately. Experimental results confirm the good performances of a compact antenna with the size of 0.26 λ0 × 0.26 λ0 × 0.026 λ0. The obtained 10‐dB impedance bandwidths can cover the two required bands. The 3‐dB axial ratio (AR) bandwidths cover the lower band and the upper band from 2.425 to 2.46 GHz. In addition, a wide 3‐dB AR beamwidth of 200° is obtained at 2.45 GHz. The simple structure and good performances make this antenna a good candidate for handheld devices and vehicular applications.
Generalised double line voltage synthesis strategy for three‐to‐N phase matrix converter
Authors: Wang Rutian , Wang Xue , Liu Ruitong , Zhang Jiawei , Mu Xingjun
Published: January 2018

This study proposes a generalised double line voltage synthesis strategy for 3 × N matrix converter. This strategy is simple without segment partitions and combinations, and it can be easily extended to any number of output phases. In order to gain the maximum VTR, the input line‐to‐line voltages and the ‘source key’ are selected reasonably, according to the polarity of the input and output phase voltages which have maximum absolute value. The relationships between input and output voltages are obtained and the general expressions of duty ratios are derived. Further, input currents are analysed when input voltages are balanced or unbalanced. In addition, this study also proposes an innovative arrangement of switching sequence, which makes the relationship of duty ratios only one fixed case. This strategy reduces the complexity of control algorithm and inherits the advantage of traditional method. Desired output voltages are realised under both balanced and unbalanced input voltages. The feasibility and effectiveness of the proposed strategy are validated through the experimental results of 3 × 3 MC and 3 × 5 MC.
Controllable preparation and photocatalytic activity of ZnO microstructures with different morphology
Authors: Qin Xiaofang , Wang Feng , Yang Lixia , Xu Yanbin , Yang Zhenglong , Gao Shanmin
Published: January 2018

Zinc oxide (ZnO) microstructures were successfully prepared by hydrothermal synthesis with PEG4000 at 120°C for 24 h. The crystalline phase and morphology of ZnO microstructures were characterised by X‐ray diffraction and scanning electron microscopy. The results show that the rod‐like, flower‐like and dumbbell‐shaped ZnO microstructures can be easily controlled by varying the amount of PEG4000. The photoluminescence spectra of ZnO microstructures with different morphology at room temperature show four emission peaks at about 362, 389, 421 and 487 nm. The photocatalytic activities of ZnO microstructures are evaluated by degradation of methylene blue (MB) under ultraviolet light irradiation, and the degradation rates of MB with rod‐like, flower‐like and dumbbell‐shaped ZnO microstructures reached 94.8, 95.4 and 70.9%, respectively.
Magnetic neutron star cooling and microphysics
Authors: Potekhin A. Y. , Chabrier G.
Published: January 2018

Aims. We study the relative importance of several recent updates of microphysics input to the neutron star cooling theory and the effects brought about by superstrong magnetic fields of magnetars, including the effects of the Landau quantization in their crusts.

Methods. We use a finite-difference code for simulation of neutron-star thermal evolution on timescales from hours to megayears with an updated microphysics input. The consideration of short timescales (≲1 yr) is made possible by a treatment of the heat-blanketing envelope without the quasistationary approximation inherent to its treatment in traditional neutron-star cooling codes. For the strongly magnetized neutron stars, we take into account the effects of Landau quantization on thermodynamic functions and thermal conductivities. We simulate cooling of ordinary neutron stars and magnetars with non-accreted and accreted crusts and compare the results with observations.

Results. Suppression of radiative and conductive opacities in strongly quantizing magnetic fields and formation of a condensed radiating surface substantially enhance the photon luminosity at early ages, making the life of magnetars brighter but shorter. These effects together with the effect of strong proton superfluidity, which slows down the cooling of kiloyear-aged neutron stars, can explain thermal luminosities of about a half of magnetars without invoking heating mechanisms. Observed thermal luminosities of other magnetars are still higher than theoretical predictions, which implies heating, but the effects of quantizing magnetic fields and baryon superfluidity help to reduce the discrepancy.
Interpretation of increased energetic particle flux measurements by SEPT aboard the STEREO spacecraft and
contamination
Authors: Wraase S. , Heber B. , Böttcher S. , Bucik R. , Dresing N. , Gómez-Herrero R. , Klassen A. , Müller-Mellin R.
Published: January 2018

Context. Interplanetary (IP) shocks are known to be accelerators of energetic charged particles observed in-situ in the heliosphere. However, the acceleration of near-relativistic electrons by shocks in the interplanetary medium is often questioned. On 9 August 2011 a corotating interaction region (CIR) passed STEREO B (STB), which resulted in a flux increase in the electron and ion channels of the Solar Electron and Proton Telescope (SEPT). Because electron measurements in the few keV to several 100 keV range rely on the so-called magnet foil technique, which is utilized by SEPT, ions can contribute to the electron channels.

Aim. We aim to investigate whether the flux increase in the electron channels of SEPT during the CIR event on 9 August 2011 is caused by ion contamination only.

Methods. We compute the SEPT response functions for protons and helium utilizing an updated GEANT4 model of SEPT. The CIR energetic particle ion spectra for protons and helium are assumed to follow a Band function in energy per nucleon with a constant helium to proton ratio.

Results. Our analysis leads to a helium to proton ratio of 16.9% and a proton flux following a Band function with the parameters I0 = 1.24 × 104 (cm2 s sr MeV nuc−1)−1, Ec = 79 keV nuc−1, and spectral indices of γ1 = −0.94 and γ2 = −3.80, which are in good agreement with measurements by the Suprathermal Ion Telescope (SIT) aboard STB.

Conclusions. Since our results explain the SEPT measurements, we conclude that no significant amount of electrons were accelerated between 55 and 425 keV by the CIR.
The Use of Principal Component Analysis for Source Identification of PM2.5 from Selected Urban and Regional Background Sites in Poland
Authors: Błaszczak Barbara
Published: January 2018

The paper reports the results of the measurements of water-soluble ions and carbonaceous matter content in the fine particulate matter (PM2.5), as well as the contributions of major sources in PM2.5. Daily PM2.5 samples were collected during heating and non-heating season of the year 2013 in three different locations in Poland: Szczecin (urban background), Trzebinia (urban background) and Złoty Potok (regional background). The concentrations of PM2.5, and its related components, exhibited clear spatiotemporal variability with higher levels during the heating period. The share of the total carbon (TC) in PM2.5 exceeded 40% and was primarily determined by fluctuations in the share of OC. Sulfates (SO42-), nitrates (NO3-) and ammonium (NH4+) dominated in the ionic composition of PM2.5 and accounted together ~34% (Szczecin), ~30% (Trzebinia) and ~18% (Złoty Potok) of PM2.5 mass. Source apportionment analysis, performed by PCA-MLRA model (Principal Component Analysis – Multilinear Regression Analysis), revealed that secondary aerosol, whose presence is related to oxidation of gaseous precursors emitted from fuel combustion and biomass burning, had the largest contribution in observed PM2.5 concentrations. In addition, the contribution of traffic sources together with road dust resuspension, was observed. The share of natural sources (sea spray, crustal dust) was generally lower.
Spatial distribution of pollutants in the area of the former CHP plant
Authors: Cichowicz Robert
Published: January 2018

The quality of atmospheric air and level of its pollution are now one of the most important issues connected with life on Earth. The frequent nuisance and exceedance of pollution standards often described in the media are generated by both low emission sources and mobile sources. Also local organized energy emission sources such as local boiler houses or CHP plants have impact on air pollution. At the same time it is important to remember that the role of local power stations in shaping air pollution immission fields depends on the height of emitters and functioning of waste gas treatment installations. Analysis of air pollution distribution was carried out in 2 series/dates, i.e. 2 and 10 weeks after closure of the CHP plant. In the analysis as a reference point the largest intersection of streets located in the immediate vicinity of the plant was selected, from which virtual circles were drawn every 50 meters, where 31 measuring points were located. As a result, the impact of carbon dioxide, hydrogen sulfide and ammonia levels could be observed and analyzed, depending on the distance from the street intersection.