bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the process of TC4 powders prepared by electrode induction melting gas atomization for laser 3D printing
Authors: Xie B , Fan Y Z , Miao Q D
Published: November 2019

This study employed TC4 rod as raw material to fabricate TC4 powders for laser 3D printing via electrode induction melting gas atomization (EIGA). The morphologies, phase compositions, particle size distributions, apparent densities and flowabilities of the powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle size analyzer (LPS) and Hall flowmeter, respectively. Moreover, the effects of gas atomization pressure and melting temperature on the yield of TC4 powders for laser 3D printing were studied. The results showed that TC4 powders morphology was nearly regular spherical. The particle size of TC4 powders showed a single peak normal distribution, mainly distributed in the range of 15−180 μm. The powder was α’−Ti of a single phase solid solution. The optimum parameters were gas atomization pressure of 5MPa, melting temperature of 1750°. Under the optimized condition, the average particle size D50 was 60.2 μm, the yield of printable TC4 powders was 35.6%, the flowability was 41.2 s/50g, the apparent density was 2.76 g/cm3 and oxygen content was 800 ppm, which was in line with the ASTM test standard and was conformed to the requirement for laser 3D printing.
Research of unpolluted deoxidization technology with applied electric field
Authors: Jia J X , Guo Q T , Li D G , Liao X W , Peng C L
Published: November 2019

A commercial experiment system of unpolluted deoxidization with applied electric field is designed and fabricated based on laboratory and pilot research. A simulation model for the electrochemical deoxidization system between molten steel and slag with direct current electric field is found and calculated. A series of research work has been carried out in order to explore the influence of the various technology parameters on the electrochemical deoxidization efficiency. The effects and influences of the electric field parameters, the electrode parameters, the properties of the molten slag and molten steel on the distribution of the current density in the electrochemical deoxidization system are analyzed according to the simulation experiments and the commercial experiments. The simulation results are verified based on experiments. The result shows that the oxygen transfers from the molten slag into the molten steel without electric field because of the high oxidizing slag. And the electrochemical deoxidization can be carried out effectively with the application of electric field. The maximum deoxidization rate can reach to 11.3×10−6·min−1 and the deoxidization rate can be improved by increasing oxygen ion current. Increasing both of the mass transfer coefficient and the reaction interface area can increase the oxygen ion current between the steel and slag.
Validation of constitutive models for experimental stress-strain relationship of high-strength steel sheets under uniaxial tension
Authors: Chen J J , Lian C W , Lin J P
Published: November 2019

The constitutive relationship between stress and strain is one of the important issues in numerical simulation of metal forming. For steel, there are two kinds of constitutive models wildly used. One is power law like Ludwik and Swift. The other is saturation models like Voce and Hockett-Sherby. It is necessary to determine the most appropriate model and parameters for newly developed high strength steels. In order to describe the ultra-high strength dual phase and quenching and partitioning steels, uniaxial tensile tests with the aid of digital image correlation techniques were performed to analyse the strain field over the whole gauge section as well as the element close to the necking point. Through experimental data analysis and numerical fitting, the validity of different models have been confirmed. It shows that equation of Hockett-Sherby model has the best fitting accuracy and high strength steels require a model with more parameters. The extrapolated weighting coefficient of combined Swift and Hockett-Sherby models is characterized, which is proved to improve the accuracy of the numerical simulation of forming of ultra-high strength steels based on the conventional tensile tests.
A modified mathematical model for end-point carbon prediction of BOF based on off-gas analysis
Authors: Lin W H , Sun J K , Zhou K X , Liu Q , Jiao S Q , Zhang J S , Su X , Liu M , Huang Y C , Li N
Published: November 2019

Several models for end-point carbon prediction of BOF(Basic Oxygen Furnace) based on off-gas analysis were studied in this paper. The advantages and disadvantages of the integral model, the exponential decay model and the cubic fitting model were analyzed respectively. Based on analysis of the characteristics of the decarburization rate curve, a new exponential model was established by the introduction of a correction algorithm. The principle of the proposed model involves applying the decarburization rate curve and the descending gradient of the historical heats to obtain the average decarburization curve and reference decarburization efficiency coefficient using the regression fitting method. According to the deviation between the actual and the predicted decarburization curves, the decarburization efficiency coefficient was corrected to improve the prediction accuracy. Plant trials were carried out in a 210 t converter to compare the performance of the mentioned models. The results showed that the new model exhibited better adaptability and higher accuracy than the other ones. The hit ratio of the new model reached more than 90% for the prediction of end-point carbon content within a tolerance of ±0.02%.
Probability based global sensitivity analysis of fatigue reliability of steel structures
Authors: Kala Z
Published: November 2019

This article focuses on reliability-oriented global sensitivity analysis of the fatigue limit state of a steel member stressed by many times repeated loading. The fatigue limit state is associated with fatigue failure, which is caused by brittle fracture due to propagation of a fatigue crack from initial to critical size. The fatigue crack propagation is analysed using linear fracture mechanics. The fundamental question in terms of structural reliability is how significant is the effect of input random quantities on the probability of failure. A new type of global sensitivity analysis subordinated to a contrast identified the equivalent stress range and initial edge crack length as random quantities that most significantly influence the failure probability. The new findings obtained using the contrast-based global sensitivity analyses show interaction effects that are unusually strong in comparison with some results of Sobol’s sensitivity analysis aimed at the reliability of structures. The sensitivity indices are estimated using double-nested-loop simulation of the Latin Hypercube Sampling method.
Formation and decomposition of Widmanstätten austenite in GOES belt-casted strips
Authors: Vodárek V , Reip C-P , Smetana B , Volodarskaja A
Published: November 2019

This contribution deals with the formation and decomposition of Widmanstätten austenite during solidification of the thin belt-casted strips made of a grain oriented electrical steel (GOES). Solidification of liquid steel started with the formation of δ-ferrite. Cooling in the δ + γ phase field resulted in the formation of a small fraction of Widmanstätten austenite by displacive mechanism accompanied by carbon partition. Widmanstätten austenite laths formed flat low energy interface facets along ferrite grain boundaries. In order to minimize the interfacial energy, ferrite grain boundaries in the vicinity of flat austenite/ferrite facets migrated. It resulted in the formation of either straight or zig-zag ferrite boundaries. Intensive precipitation of sulphides along ferrite/austenite interfaces made it possible to study the early stages of austenite decomposition at the end of the δ + γ phase field. Complex sulphides containing chromium, manganese, iron and copper were identified as the Cr2CuS4 phase. Decomposition of austenite started with the formation of epitaxial ferrite. This was accompanied by further partitioning of carbon into remaining austenite. The growth of epitaxial ferrite into the flat ferrite/austenite interface facets along ferrite grain boundaries resulted in a wavy shape of these boundaries. Finally, remaining carbon rich austenite transformed either to pearlite or plate martensite.
Study of grain distribution during friction stir welding of Al-Zn-Mg alloys using numerical simulation
Authors: Wu Y F , Yu J , Yang Z , Deng Y L
Published: November 2019

During friction stir welding (FSW) of Al-Zn-Mg alloys, the grain size of the welded material significantly affects its mechanical properties. In this study, the FSW process was simulated using the finite element method (FEM). Subsequently, the Zener-Hollomon parameters and grain size were calculated using the results of the stimulation of the temperature and strain rate fields. Also, the accuracy of numerical simulation was proved by experiments. It was found that the Zener-Hollomon relationship correctly predicted the grain size for the weld stirring zone (SZ) and thermal-mechanical affected zone (TMAZ), and we concluded that low rotating and high welding speeds resulted in smaller grain sizes for the SZ. Moreover, the high welding speed could effectively improve the grain condition at the edge of the TMAZ and the specific relationship between Zener-Hollomon parameters and the average grain diameter of SZ can be expressed as: Z = 9.09 × 1013
d
−4.74.
Fabrication of Ag micro-patterns by electrohydrodynamic jet printing
Authors: Lv H , Wang X
Published: November 2019

Electrohydrodynamic jet printing is a rapid manufacturing method in additive manufacturing fields, which is employed to generate micro-nano patterns, functional structures, sensors and electronics in recent years. It is a rapid manufacturing, low-cost, mask-free route to manufacture one dimensional to three dimensional structures by nanoink. In this paper, silver dots, lines and designed patterns are printed by electrohydrodynamic jet printing. The results are stable and uniform, which can be adjusted by printing parameters. With high voltage, large pulse width or small stand-off distance, the size of dots increase. By increasing frequency or decreasing shifting speed, the distance between dots becomes short, then the structures are getting into lines from dots. Multi-layer silver lines are characterized by X-ray imaging and exhibit good absorption of X-ray, leading to the significant radiation attenuation effectiveness. The printed silver structures are good candidates for radiation shielding in electronics and circuit boards.
Constitutive modeling of dynamic recrystallization and precipitation behavior of Nb and Ti of Q1030 high strength steel
Authors: Wang J J , Kang Y L , Liu Y L , Yu H
Published: November 2019

The thermal deformation and precipitation behavior at 900-1100° and strain rate of 0.1-5s−1 were studied by Gleeble-3800 thermal simulator of Q1030 high strength steel. The activation energy of hot deformation in austenite region was determined by regression method, and the hot deformation equation of the Q1030 high strength steel was established. The critical strain and peak strain of dynamic recrystallization were predicted accurately by fitting the inflection point with cubic polynomial of curve of Q1030 high strength steel, and relationship between critical strain and Z parameter was established. Finally, the precipitation behavior of Nb and Ti particles during low strain rate deformation was studied, the results show that the precipitated phases in steel are rectangular TiN, quadratic (Nb, Ti) (C, N) carbonitride, elliptical (Nb, Ti) C carbide and NbC. Thermodynamic calculation shows that the order of precipitation of the second phase in steel is TiN, TiC, NbC and NbN.
Anomalous concentration dependence of the thermal conductivity of refractory sintered binary nano-composites TiN-ALN and ZrC-ZrB2
Authors: Zarichniak Y , Ordanyan S
Published: November 2019

An abnormal concentration dependence of the thermal conductivity of nanocomposites Titanium Nitride-Aluminum Nitride and zirconium carbide-zirconium diboride has been experimentally established from the volume fraction of components. An explanation of the nature of the anomalous dependence and a technique for an approximate estimation of the dependence of the thermal conductivity of a nanocomposite on the volume fraction of components are proposed. Oxygen-free refractory compounds - covalent and metal-like active investigated in the development of new ceramic materials used for achieving higher physical and mechanical characteristics as well as for use in extreme conditions in mechanical engineering, nuclear engineering, aviation, special equipment. The development of technology is constantly stimulates the creation of new materials, which must manifest a complex of properties rarely show by one substance, such decisions cannot find the formation of composite (hetero) materials. In the case of eutectic systems with diffusive non-interacting refractory components, used for the synthesis of composite ceramic materials in a highly thermodynamic state, the possibility of co-building a new group of ceramics with interphase boundary (of eutectics “coarse conglomerate”) with anomalous concentration dependences of the physical and mechanical characteristics of composite materials (flexural strength and modulus of elasticity, super plasticity – elongation more than 500%, tensile, strength and fracture toughness) and thermal properties (thermal conductivity and thermal diffusivity) [1-3].
Functionalization of Fe3O4/TiO2/BiOCl nanocomposites using Sargassum crassifolium extract as magnetic nanophotocatalyst for cadmium sequestration
Authors: Cumba R M T , Capangpangan R Y , Alguno A C
Published: November 2019

We report on the synthesis of Fe3O4/TiO2/BiOCl nanocomposites using Sargassum crassifolium extract as magnetic nanophotocatalyst for cadmium sequestration. Utilization of nanotechnology via surface engineering and functionalization has been considered for heavy metals sequestration. In this work, we are going to synthesize Fe3O4/TiO2/BiOCl nanocomposites via green synthesis for cadmium heavy metal sequestration on wastewater. Synthesis of nanocomposites includes the fabrication of functionalized Fe3O4 magnetic nanoparticles using Sargassum crassifolium extract followed by the fabrication of TiO2 and finally capped with BiOCl to complete the Fe3O4/TiO2/BiOCl nanocomposites. Experimental results revealed that successful green synthesis of magnetic Fe3O4 via was observed in the Fast Fourier transform infrared spectra with the presence of Fe-O vibrations at 580 cm−1. In addition, the band around 1000 cm−1 was observed suggesting the TiO2 was successfully formed the peak around 1155 cm−1 can be attributed to Bi-Cl bond for the formation of BiOCl. Moreover, the presence of 370 nm peak in the ultraviolet-visible spectra suggests that Fe3O4/TiO2/BiOCl nanocomposites were successfully synthesized. Varied amount of cadmium on wastewater was efficiently sequestered via photocatalysis with an efficiency of about 83%. This straight forward green synthesis of Fe3O4/TiO2/BiOCl nanocomposites is a potential photocatalysts for cadmium sequestration.
Photosynthetic cyclic electron transport provides ATP for homeostasis during trap closure in Dionaea muscipula
Authors: Maurer Daniel , Weber Daniel , Ballering Eva , Alfarraj Salah , Albasher Gada , Hedrich Rainer , Werner Christiane , Rennenberg Heinz
Published: November 2019

Background and Aims

The processes connected with prey capture and the early consumption of prey by carnivorous Dionaea muscipula require high amounts of energy. The aim of the present study was to identify processes involved in flytrap energy provision and ATP homeostasis under these conditions.

Methods

We determined photosynthetic CO2 uptake and chlorophyll fluorescence as well as the dynamics of ATP contents in the snap traps upon closure with and without prey.

Key Results

The results indicate that upon prey capture, a transient switch from linear to cyclic electron transport mediates a support of ATP homeostasis. Beyond 4 h after prey capture, prey resources contribute to the traps’ ATP pool and, 24 h after prey capture, export of prey-derived resources to other plant organs may become preferential and causes a decline in ATP contents.

Conclusions

Apparently, the energy demand of the flytrap for prey digestion and nutrient mining builds on both internal and prey-derived resources.
Machine learning approaches and databases for prediction of drug–target interaction: a survey paper
Authors: Bagherian Maryam , Sabeti Elyas , Wang Kai , Sartor Maureen A , Nikolovska-Coleska Zaneta , Najarian Kayvan
Published: November 2019

The task of predicting the interactions between drugs and targets plays a key role in the process of drug discovery. There is a need to develop novel and efficient prediction approaches in order to avoid costly and laborious yet not-always-deterministic experiments to determine drug–target interactions (DTIs) by experiments alone. These approaches should be capable of identifying the potential DTIs in a timely manner. In this article, we describe the data required for the task of DTI prediction followed by a comprehensive catalog consisting of machine learning methods and databases, which have been proposed and utilized to predict DTIs. The advantages and disadvantages of each set of methods are also briefly discussed. Lastly, the challenges one may face in prediction of DTI using machine learning approaches are highlighted and we conclude by shedding some lights on important future research directions.
EpiDISH web server: Epigenetic Dissection of Intra-Sample-Heterogeneity with online GUI
Authors: Zheng Shijie C , Breeze Charles E , Beck Stephan , Dong Danyue , Zhu Tianyu , Ma Liangxiao , Ye Wei , Zhang Guoqing , Teschendorff Andrew E
Published: November 2019

It is well recognized that cell-type heterogeneity hampers the interpretation of Epigenome-Wide Association Studies (EWAS). Many tools have emerged to address this issue, including several R/Bioconductor packages that infer cell-type composition. Here we present a web application for cell-type deconvolution, which offers the functionality of our EpiDISH Bioconductor/R package in a user-friendly GUI environment. Users can upload their data to infer cell-type composition and differentially methylated cytosines in individual cell-types for a range of different tissues.

Availability and implementation

EpiDISH web server is implemented with Shiny in R, and is freely available at https://www.biosino.org/EpiDISH/.
Already at the bottom? Demographic declines are unlikely further to undermine genetic diversity of a large Arctic ungulate: muskox, Ovibos moschatus (Artiodactyla: Bovidae)
Authors: Prewer Erin , Kutz Susan , Leclerc Lisa Marie , Kyle Christopher J
Published: November 2019

Low genetic diversity is associated with low fitness and evolutionary potential, yet the demographic and life-history traits of some species contribute to low genetic diversity, without empirical evidence of negative impacts on fitness. Modelling past and future trajectories of genetic diversity under different demographic scenarios can provide insight into how genetic variation might impact population fitness. The muskox is an Arctic species that has undergone multiple population bottlenecks and, although populations have rebounded repeatedly, two large populations have recently declined by > 50%. It is unclear how these demographic patterns influence muskox genetic diversity and fitness. We compared the genetic diversity of Canadian muskox populations undergoing opposing population trends. Genotyping 84 mainland and 244 Victoria Island individuals at ten microsatellite loci revealed low genetic variation (Victoria Island, mean allelic richness 1.66, expected heterozygosity 0.16; mainland, mean allelic richness 2.58, expected heterozygosity 0.41), with no evidence of further reductions in diversity subsequent to recent demographic declines. Bayesian modelling showed that a 1900s bottleneck contributed to the lack of diversity in contemporary populations, and forward-in-time simulations suggested little effect on genetic diversity over the next 100 years. Muskoxen might have reached a genetic diversity minimum, and additional research will be needed to determine their capacity to adapt to rapid changes in selective pressures in a rapidly changing Arctic.
Intersecting Epidemics: Incident Syphilis and Drug Use in Women Living With Human Immunodeficiency Virus in the United States (2005–2016)
Authors: Dionne-Odom Jodie , Westfall Andrew O , Dombrowski Julia C , Kitahata Mari M , Crane Heidi M , Mugavero Michael J , Moore Richard D , Karris Maile , Christopoulos Katerina , Geng Elvin , Mayer Kenneth H , Marrazzo Jeanne
Published: November 2019

Background

Rates of early syphilis in US women are steadily increasing, but predictors of infection in this group are not clearly defined.

Methods

This retrospective analysis focused on women enrolled in the US CFAR Network of Integrated Clinical Systems cohort between January 2005 and December 2016 with syphilis testing performed. The primary outcome of incident syphilis infection was defined serologically as a newly positive test with positive confirmatory testing after a negative test or a 2-dilution increase in rapid plasma regain titer. Infection rates were calculated for each woman-year in care with testing. Predictors of syphilis were sought among sociodemographics, clinical information, and self-reported behaviors. Multivariable logistic regression models were created; a subgroup analysis assessed predictors in women of reproductive age.

Results

The annual rate of incident syphilis among 4416 women engaged in human immunodeficiency virus (HIV) care and tested during the 12-year study period was 760/100 000 person-years. Independent predictors of infection were injection drug use as a risk factor for HIV acquisition (aOR, 2.2; 95% CI, 1.3–3.9), hepatitis C infection (aOR, 1.9; 95% CI, 1.1–3.4), black race (aOR, 2.2; 95% CI, 1.3–3.7 compared with white race), and more recent entry to care (since 2005 compared with 1994–2004). Predictors were similar in women aged 18–49.

Conclusions

Syphilis infection is common among US women in HIV care. Syphilis screening and prevention efforts should focus on women reporting drug use and with hepatitis C coinfection. Future studies should identify specific behaviors that mediate syphilis acquisition risk in women who use drugs.
Prognostic assessment of valvular surgery in active infective endocarditis: multicentric nationwide validation of a new score developed from a meta-analysis
Authors: Varela Barca Laura , Fernández-Felix Borja M , Navas Elorza Enrique , Mestres Carlos A , Muñoz Patricia , Cuerpo-Caballero Gregorio , Rodríguez-Abella Hugo , Montejo-Baranda Miguel , Rodríguez-Álvarez Regino , Gutiérrez Díez Francisco , Goenaga Miguel Angel , Quintana Eduard , Ojeda-Burgos Guillermo , de Alarcón Arístides , Vidal-Bonet Laura , Centella Hernández Tomasa , López-Menéndez Jose ,   on behalf of the Spanish Collaboration on Endocarditis—Grupo de Apoyo al Manejo de la Endocarditis infecciosa en ESpaña (GAMES)
Published: November 2019

OBJECTIVES

Several risk prediction models have been developed to estimate the risk of mortality after valve surgery for active infective endocarditis (IE), but few external validations have been conducted to assess their accuracy. We previously developed a systematic review and meta-analysis of the impact of IE-specific factors for the in-hospital mortality rate after IE valve surgery, whose obtained pooled estimations were the basis for the development of a new score (APORTEI). The aim of the present study was to assess its prognostic accuracy in a nationwide cohort.

METHODS

We analysed the prognostic utility of the APORTEI score using patient-level data from a multicentric national cohort. Patients who underwent surgery for active IE between 2008 and 2018 were included. Discrimination was evaluated using the area under the receiver operating characteristic curve, and the calibration was assessed using the calibration slope and the Hosmer–Lemeshow test. Agreement between the APORTEI and the EuroSCORE I was also analysed by Lin’s concordance correlation coefficient (CCC), the Bland–Altman agreement analysis and a scatterplot graph.

RESULTS

The 11 variables that comprised the APORTEI score were analysed in the sample. The APORTEI score was calculated in 1338 patients. The overall observed surgical mortality rate was 25.56%. The score demonstrated adequate discrimination (area under the receiver operating characteristic curve = 0.75; 95% confidence interval 0.72–0.77) and calibration (calibration slope = 1.03; Hosmer–Lemeshow test P = 0.389). We found a lack of agreement between the APORTEI and EuroSCORE I (concordance correlation coefficient = 0.55).

CONCLUSIONS

The APORTEI score, developed from a systematic review and meta-analysis, showed an adequate estimation of the risk of mortality after IE valve surgery in a nationwide cohort.
Testing sustained soil-to-soil contact as an approach for limiting the abiotic influence of source soils during experimental microbiome transfer
Authors: Trexler Ryan V , Bell Terrence H
Published: November 2019

Experimental separation of the biotic and abiotic components of soil will help in understanding the role of taxonomy and composition in soil microbiome function. The most common approach to soil microbiome transfer involves direct dilution of a non-sterile source soil into sterile recipient soils, introducing both microorganisms and soil compounds, leaving abiotic and biotic factors confounded. Here, we contrast microbiome transfer into sterile recipient soils through (i) direct soil transfer at two dilutions and (ii) a new approach, sustained contact between source and recipient soils. Sustained soil-to-soil contact retains separation between source and recipient soils, allows for multiple colonization events and increases confidence that microorganisms observed in recipient soils are active and growing. Each approach produced distinct microbiomes in recipient soils after 1 and 6 weeks of incubation, indicating that transfer method impacts microbial composition. The extent to which recipient microbiomes resembled source microbiomes varied by soil type, although in general, direct soil transfer appeared to most closely approximate source microbiomes. However, irrespective of transfer method, most bacterial sequences in recipient soils were from organisms transferred through all methods. We discuss the merits of each method for controlled soil microbiome studies.
Clinical Impacts and Outcomes With Possible Donor-Derived Infection in Infected Donor Liver Transplantation: A Single-Center Retrospective Study in China
Authors: Tong Li , Hu Xiao-Guang , Huang Fa , Huang Shun-Wei , Li Li-Fen , Tang Zhao-Xia , Yao Ji-You , Xu Jing-Hong , Zhu Yan-Ping , Chen Yin-Hua , He Xiao-Shun , Guan Xiang-Dong , Cai ChangJie
Published: November 2019

Background

Information on possible donor-derived transmission events in China is limited. We evaluated the impacts of liver transplantation from infected deceased-donors, analyzed possible donor-derived bacterial or fungal infection events in recipients, and evaluated the etiologic agents’ characteristics and cases outcomes.

Methods

A single-center observational study was performed from January 2015 to March 2017 to retrospectively collect data from deceased-donors diagnosed with infection. Clinical data were recorded for each culture-positive donor and the matched liver recipient. The microorganisms were isolated and identified, and antibiotic sensitivity testing was performed. The pathogens distribution and incidence of possible donor-derived infection (P-DDI) events were analyzed and evaluated.

Results

Information from 211 donors was collected. Of these, 82 donors were infected and classified as the donation after brain death category. Overall, 149 and 138 pathogens were isolated from 82 infected donors and 82 matched liver recipients, respectively. Gram-positive bacteria, Gram-negative bacteria, and fungi accounted for 42.3% (63 of 149), 46.3% (69 of 149), and 11.4% (17 of 149) of pathogens in infected donors. The incidence of multidrug-resistant bacteria was high and Acinetobacter baumannii was the most concerning species. Infections occurred within the first 2 weeks after liver transplantation with an organ from an infected donor. Compared with the noninfection recipient group, the infection recipient group experienced a longer mechanical ventilation time (P = .004) and intensive care unit stay (P = .003), a higher incidence of renal dysfunction (P = .026) and renal replacement therapy (P = .001), and higher hospital mortality (P = .015). Possible donor-derived infection was observed in 14.6% of cases. Recipients with acute-on-chronic liver failure were more prone to have P-DDI than recipients with other diseases (P = .007; odds ratio = 0.114; 95% confidence interval, .025–.529).

Conclusions

When a liver recipient receives a graft from an infected deceased-donor, the postoperative incidence of infection is high and the infection interval is short. In addition, when a possible donor-derived, drug-resistant bacterial infection occurs, recipients may have serious complications and poor outcomes.
Gillespie-Lindenmayer systems for stochastic simulation of morphogenesis
Authors: Cieslak Mikolaj , Prusinkiewicz Przemyslaw
Published: November 2019

Lindenmayer systems (L-systems) provide a useful framework for modelling the development of multicellular structures and organisms. The parametric extension of L-systems allows for incorporating molecular-level processes into the models. Until now, the dynamics of these processes has been expressed using differential equations, implying continuously valued concentrations of the substances involved. This assumption is not satisfied, however, when the numbers of molecules are small. A further extension that accounts for the stochastic effects arising in this case is thus needed. We integrate L-systems and the Gillespie’s Stochastic Simulation Algorithm to simulate stochastic processes in fixed and developing linear structures. We illustrate the resulting formalism with stochastic implementations of diffusion-decay, reaction-diffusion and auxin-transport-driven morphogenetic processes. Our method and software can be used to simulate molecular and higher-level spatially explicit stochastic processes in static and developing structures, and study their behaviour in the presence of stochastic perturbations.
MRI Evaluation of the Contralateral Breast in Women with Recently Diagnosed Breast Cancer: 2-Year Follow-up
Authors: Debruhl Nanette D , Lee Su-Ju , Mahoney Mary C , Hanna Lucy , Tuite Catherine , Gatsonis Constantine A , Lehman Constance
Published: November 2019

Objective

The American College of Radiology Imaging Network Trial 6667 showed that MRI can detect cancer in the contralateral breast that is missed by mammography and clinical examination at the time of the initial breast cancer diagnosis, based on 1-year follow-up. This study is a continuation of the trial that evaluates the diagnostic accuracy of MRI for contralateral breast cancer after 2 years of follow-up.

Methods

In total, 969 women with a diagnosis of unilateral breast cancer and no clinical or imaging abnormalities in the contralateral breast underwent breast MRI. The cancer status of all participants was monitored for 2 years after the initial MRI. Follow-up included documentation of any clinical, imaging, or interventional procedures performed. A study participant was considered positive for cancer if she had a tissue diagnosis of in situ or invasive breast cancer in the contralateral breast within 730 days of her initial MRI.

Results

Three additional cancers were diagnosed in the study population in the second year of the trial. The diagnostic yield for MRI for the 2-year period was 3% (31/969). After 2 years of follow-up, breast MRI has a sensitivity of 86% and specificity of 88% for detection of contralateral breast cancer. Its negative predictive value was 99%, and its positive predictive value was 22%. These values did not change significantly from the 1-year data.

Conclusion

A negative contralateral breast MRI has a very high and reliable negative predictive value over 2 years, and, therefore, is helpful in managing and counseling patients during the period of initial diagnosis and early treatment.
On the Epistemic Status of Prenatal Ultrasound: Are Ultrasound Scans Photographic Pictures?
Authors: Favaretto Maddalena , Vears Danya F , Borry Pascal
Published: November 2019

Medical imaging is predominantly a visual field. In this context, prenatal ultrasound images assume intense social, ethical, and psychological significance by virtue of the subject they represent: the fetus. This feature, along with the sophistication introduced by three-dimensional (3D) ultrasound imaging that allows improved visualization of the fetus, has contributed to the common impression that prenatal ultrasound scans are like photographs of the fetus. In this article we discuss the consistency of such a comparison. First, we investigate the epistemic role of both analogic and digital photographic images as visual information-providing representations holding a high degree of objectivity. Second, we examine the structure and process of production of ultrasound scans and argue that a comparison between two-dimensional (2D) ultrasound and photography is justified. This is in contrast to 3D ultrasound images that, due to the intensive mathematical processing involved in their production, present some structural issues that obfuscate their ontological and epistemic status.
NATO's About-Face: Adaptation to Gender Mainstreaming in an Alliance Setting
Authors: Hardt Heidi , von Hlatky Stéfanie
Published: November 2019

Scholars in global security studies have only recently focused attention on how and why international security organizations (ISOs) adapt. Since the United Nations Security Council's issuance of Resolution 1325, some ISOs have enacted changes to implement gender mainstreaming. The concept involves incorporating gender-based analyses in policy and planning and increasing women's representation. Drawing on interviews with seventy-one elites and a dataset of ninety-seven NATO gender guidelines, this article introduces an original argument for why NATO adapted to gender mainstreaming. Such adaptation is surprising given the military's historical resistance to gender considerations and that civilian bodies typically enact reforms. Findings indicate that other ISOs were substantially influential in the process and that institutional incentives built into NATO's military bodies drove military officials to implement mainstreaming in practice. Additionally, military elites perceived a link between gender mainstreaming and operational effectiveness, which further consolidated organization-wide adaptation. This study challenges long-held assumptions about militaries’ resistance to gender-related changes. It also offers one of the first empirical assessments of gender mainstreaming in an ISO.
Description of Enteropathic Escherichia coli Species in Pediatric Patients at a Quaternary Children’s Hospital
Authors: Nycz Bryan T , Pretty Kristin , Gomez-Trujillo Angel , Sanchez Brenda , Dominguez Samuel R
Published: November 2019

Background

The epidemiology, demographics, clinical presentations, and outcomes associated with enteroaggregative Escherichia coli (EAEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) pathotypes in US children are not well understood.

Methods

This study was a retrospective chart review of all pediatric patients with a stool sample submitted to the Children’s Hospital Colorado clinical microbiology laboratory for testing with the BioFire FilmArray Gastrointestinal Pathogen Panel from October 2015 through October 2017.

Results

During the study period, 5692 patient stool samples were submitted; 679 (13%) were positive for EAEC, EPEC, or ETEC. Of note, 163/232 (70%) patients with EAEC, 282/493 (57%) with EPEC, and 49/58 (85%) with ETEC had detection of at least 1 other pathogen. Of all E. coli–positive stool samples, only 158/679 (23%) were from low-risk patients who were singly infected with EAEC, EPEC, or ETEC. In this cohort, most cases were associated with acute diarrhea (50%), abdominal pain (61%), and/or cramping (49%) and presented without fever (14%), emesis (28%), or lethargy (7%). Thirteen (8%) of these 158 patients received antibiotics at the time of their initial presentation to care. Of the 145 patients who did not receive antibiotics at their initial visit, 23 (16%) returned to care due to persistence of symptoms.

Conclusions

Our results suggest that the majority of patients singly infected with EAEC, EPEC, or ETEC present with mild, self-limited, gastrointestinal (GI) complaints. Further research is needed to determine what role these pathogens might play in children who present with chronic or inflammatory GI symptoms.
Association of Body Mass Index and Serum Markers of Tissue Damage with Postoperative Pain. The Role of Lactate Dehydrogenase for Postoperative Pain Prediction
Authors: González-Callejas Cristina , Aparicio Virginia A , De Teresa Carlos , Nestares Teresa
Published: November 2019

Objectives

i) To analyze the association of body mass index (BMI) and some serum tissue damage markers with postoperative pain. ii) To establish a biochemical marker cutoff point able to predict moderate to severe postoperative pain.

Design

Cross-sectional study.

Subjects

Ninety-six adult male patients from Southern Spain (55 ± 13 years old) who underwent an inguinal hernioplasty.

Methods

Postoperative pain (eight hours after surgery) was assessed through a visual analog scale (VAS). Moderate to severe pain was defined as a VAS > 50 mm. BMI was calculated and medication, alcohol consumption, and smoking habit registered. Eight hours after surgery, some serum markers such as fibrinogen, lactate dehydrogenase (LDH), C-reactive protein, cortisol, creatine kinase, glutamic-pyruvic, glutamic oxaloacetic, and gamma-glutamyltransferase transaminases were determined by standard procedures.

Results

After adjusting for potential confounders, BMI was not associated with postoperative pain (P > 0.05). Serum fibrinogen was associated with greater postoperative pain (β = 0.333, P < 0.05). Serum LDH concentration was strongly associated with greater postoperative pain (β = 0.606, P < 0.001). Alcohol consumption was associated with higher postoperative pain (β = 0.212, P < 0.05). No associations were observed regarding age, tobacco consumption, and the rest of serum markers studied. Serum LDH concentration was able to discriminate between presence/absence of moderate to severe postoperative pain (receiver operating characteristic area under the curve = 0.655, P ≤ 0.01). An LDH concentration >204 IU/L was associated with a three-times increased odds ratio of moderate to severe postoperative pain.

Conclusions

Contrary to expectations, greater BMI was not associated with higher postoperative pain. Notwithstanding, the assessment of serum LDH might provide useful information to predict moderate to severe postoperative pain.
Detection rate is not higher for women with BBD history in breast cancer screening
Authors: Qu Penghuan , Liu Xueou , Huang Yubei , Feng Ziwei , Wang Xin , Dai Hongji , Zhang Liwen , Song Fangfang , Li Haixin , Zheng Hong , Song Fengju , Chen Kexin
Published: November 2019

Background

To investigate whether women with benign breast disease (BBD) history have higher breast cancer detection rate in screening.

Methods

We reviewed data for 33 001 female participants in Multi-modality Independent Screening Trial (MIST). Corresponding data for 6823 breast cancer patients were retrieved from the Tianjin Breast Cancer Cases Cohort (TBCCC) and analyzed for comparison.

Results

The breast cancer detection rate was 2.83‰ among women with BBD history and 3.28‰ in women without. Moreover, the proportion of carcinoma in situ (CIS) was also lower in women with BBD history than women without (7.69 versus 20.31%). In contrast, analysis of TBCCC data revealed a higher proportion of CIS in patients with BBD history (5.05%) than patients without (3.26%). Our data showed that a larger proportion of women with BBD history had undergone previous breast examinations. Additionally, among participants diagnosed with both breast cancer and BBD in MIST, we found a lower proportion of CIS in women with BBD history (11.76%) compared to women without (32.14%).

Conclusions

Women with BBD history were not found to have higher detection rate in breast cancer screening. Women with BBD history were more likely to be proactive in seeking breast examinations and to have breast cancer be diagnosed in clinic.
Institutional Trading around Corporate News: Evidence from Textual Analysis
Authors: Huang Alan Guoming , Tan Hongping , Wermers Russ
Published: November 2019

We examine institutional trading surrounding corporate news by combining a comprehensive database of newswire releases on U.S. firms with a high-frequency database of institutional trades. To identify the ability of institutions to predict or quickly interpret news, we form “news clusters” of related news about a particular firm that occurs in rapid succession. We find that institutions chiefly trade on the tone of news directly after the earliest news release in a cluster, and such news-motivated trading predicts returns over the following weeks. Our results suggest that institutional investors contribute to price efficiency through the speedy interpretation of public information.
Refugee Protection Standards in Transition: Studying German NGOs and Public Administrations
Authors: Zimmermann Inga , Rosenow-Williams Kerstin , Behmer-Prinz Katharina , Bergedieck Alina
Published: November 2019

From 2014 to 2015, the number of asylum applications increased by 155 per cent in Germany, which has severely altered Germany’s refugee response system. This article analyses resulting local-level changes in the protection standards for refugees. It sheds light on the interplay between municipal and organisational actors in implementing protections concepts and measures for refugee accommodations. The study applies a neo-institutional research framework to explain organisational behaviour at the level of non-governmental organisations and public administration asking how the security needs of refugee women are met at the “street-level bureaucracy”. Through empirical fieldwork, it shows that in 2018, gender-specific protection standards were higher than before 2014 due to mechanisms of regulative, normative and mimetic isomorphism. The joint development of Minimum Standards for the Protection of Refugees and Migrants in Refugee Accommodation Centres in 2016 by the United Nations Children's Fund, the Federal Ministry for Family Affairs, Senior Citizens, Women and Youth and numerous non-governmental organisations has supported this process. The research combines current debates in refugee studies with theoretical concepts from organisational sociology, gender studies and policy research.
Circadian and sleep/wake-dependent variations in tau phosphorylation are driven by temperature
Authors: Guisle Isabelle , Gratuze Maud , Petry Séréna , Morin Françoise , Keraudren Rémi , Whittington Robert A , Hébert Sébastien S , Mongrain Valérie , Planel Emmanuel
Published: November 2019

Study Objectives

Aggregates of hyperphosphorylated tau protein are a hallmark of Alzheimer’s disease (AD) and other tauopathies. Sleep disturbances are common in AD patients, and insufficient sleep may be a risk factor for AD. Recent evidence suggests that tau phosphorylation is dysregulated by sleep disturbances in mice. However, the physiological regulation of tau phosphorylation during the sleep–wake cycle is currently unknown. We thus aimed to determine whether tau phosphorylation is regulated by circadian rhythms, inherently linked to the sleep–wake cycle.

Methods

To answer these questions, we analyzed by Western blotting tau protein and associated kinases and phosphatases in the brains of awake, sleeping, and sleep-deprived B6 mice. We also recorded their temperature.

Results

We found that tau phosphorylation undergoes sleep-driven circadian variations as it is hyperphosphorylated during sleep but not during acute sleep deprivation. Moreover, we demonstrate that the mechanism behind these changes involves temperature, as tau phosphorylation was inversely correlated with circadian- and sleep deprivation-induced variations in body temperature, and prevented by housing the animals at a warmer temperature. Notably, similar changes in tau phosphorylation were reproduced in neuronal cells exposed to temperatures recorded during the sleep–wake cycle. Our results also suggest that inhibition of protein phosphatase 2A (PP2A) may explain the hyperphosphorylation of tau during sleep-induced hypothermia.

Conclusion

Taken together, our results demonstrate that tau phosphorylation follows a circadian rhythm driven mostly by body temperature and sleep, and provide the physiological basis for further understanding how sleep deregulation can affect tau and ultimately AD pathology.
Effects of Cognitive Load on Pure-Tone Audiometry Thresholds in Younger and Older Adults
Authors: Heinrich Antje , Ferguson Melanie A. , Mattys Sven L.
Published: November 2019

Objectives:

Cognitive load (CL) impairs listeners’ ability to comprehend sentences, recognize words, and identify speech sounds. Recent findings suggest that this effect originates in a disruption of low-level perception of acoustic details. Here, we attempted to quantify such a disruption by measuring the effect of CL (a two-back task) on pure-tone audiometry (PTA) thresholds. We also asked whether the effect of CL on PTA was greater in older adults, on account of their reduced ability to divide cognitive resources between simultaneous tasks. To specify the mechanisms and representations underlying the interface between auditory and cognitive processes, we contrasted CL requiring visual encoding with CL requiring auditory encoding. Finally, the link between the cost of performing PTA under CL, working memory, and speech-in-noise (SiN) perception was investigated and compared between younger and older participants.

Design:

Younger and older adults (44 in each group) did a PTA test at 0.5, 1, 2, and 4 kHz pure tones under CL and no CL. CL consisted of a visual two-back task running throughout the PTA test. The two-back task involved either visual encoding of the stimuli (meaningless images) or subvocal auditory encoding (a rhyme task on written nonwords). Participants also underwent a battery of SiN tests and a working memory test (letter number sequencing).

Results:

Younger adults showed elevated PTA thresholds under CL, but only when CL involved subvocal auditory encoding. CL had no effect when it involved purely visual encoding. In contrast, older adults showed elevated thresholds under both types of CL. When present, the PTA CL cost was broadly comparable in younger and older adults (approximately 2 dB HL). The magnitude of PTA CL cost did not correlate significantly with SiN perception or working memory in either age group. In contrast, PTA alone showed strong links to both SiN and letter number sequencing in older adults.

Conclusions:

The results show that CL can exert its effect at the level of hearing sensitivity. However, in younger adults, this effect is only found when CL involves auditory mental representations. When CL involves visual representations, it has virtually no impact on hearing thresholds. In older adults, interference is found in both conditions. The results suggest that hearing progresses from engaging primarily modality-specific cognition in early adulthood to engaging cognition in a more undifferentiated way in older age. Moreover, hearing thresholds measured under CL did not predict SiN perception more accurately than standard PTA thresholds.