bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of mixed-mode fracture (I-II) on PFRC specimens with various fibre proportions using an embedded cohesive crack model
Authors: Suárez F , Gálvez JC , Enfedaque A , Alberti MG
Published: August 2019

The study of fibre-reinforced concrete (FRC) has become of increasing interest in the last decades. Although it is not a new technology, it has experienced a remarkable progress with the appearance of some recommendations in the standards. More specifically, the use of polyolefin fibres has proved to increase the tensile strength of concrete without the problems usually found with steel fibres, especially those related to corrosion. This type of fibres have been studied in depth and its fracture behaviour has been successfully simulated in the past by means of an embedded crack model using a trilinear softening function. Nevertheless, these simulations have been always focused on cases where fracture took place under pure mode I conditions, namely using the classical three-point bending test on notched specimens. In this study, such embedded crack model is used to reproduce the fracture behaviour on notched specimens subjected to a modified three-point bending test that induces fracture under a combination of modes I and II. Three PFRC mixes are analysed, all of them with the same proportions of concrete components but different proportions of polyolefin fibres. The experimental and numerical diagrams properly agree and allow identifying how the increasing proportion of fibres can be reflected in the trilinear softening function that numerically drives the damage evolution.
Advanced design methodologies for steel fibre reinforced concrete and new methodology of real time quality control
Authors: Hoekstra A
Published: August 2019

Steel fibre reinforced concrete has developed over years for the use in structural applications. The material itself has undergone development into higher performing steel fibre types and thus into higher performing steel fibre concretes. Whilst in regards to standards the development went from recommendations into building codes the way of designing – linear elastic design methods or yield line theory – and the way of quality control seemed to remain unchanged from the past. This paper shall emphasize the recent development in a design tool that enables a non-linear design methodology and a new advanced way of real time quality control.
New UHPFRC bridges in the Czech Republic
Authors: Marek J , Kolísko J , Tej P , Čítek D , Komanec J , Kalný M , Vráblík L
Published: August 2019

This paper deals with new UHPFRC (Ultra High Performance Fibre Reinforced Concrete) bridges produced or constructed in 2018 in the Czech Republic. The paper includes a short description of 3 unique pedestrian bridges with load bearing structure made of UHPFRC and 2 steel bridges over the railway track with lost formwork for bridge decks and cornices made of thin UHPFRC slabs. Focus is given on the testing of the material, comparison of test specimens and summary of results from UHPFRC production in real scale. The size effect of control specimen and the results analysis is given in the last chapter. The 3 mentioned unique pedestrian bridges are Footbridge over the Lubina river in city Příbor, Pedestrian and cycle bridge in the vicinity of Black Bridges in city Tábor and Footbridge over Dřetovice stream in Vrapice - a district of Kladno city. Thin panels as permanent lost formwork for two bridges over the railway tracks are in city Přerov. All new UHPFRC structures should be worthy of attention of bridge experts and community of specialists in the field of concrete engineering.
Steel microfibres in fly ash geopolymer for multifunctional conductive composites
Authors: Mizerová C , Kusák I , Rovnaník P , Bayer P
Published: August 2019

Steel fibres in construction materials not only enhance their mechanical and fracture properties but also increase their capability of electrical conductivity. This feature thus enables the material to obtain advanced multifunctional properties that can be utilized in self-sensing and other smart applications. Fly ash geopolymers with steel microfibres in 5−30% wt. were prepared to assess the influence of the fibres on selected electrical properties of the composite (resistance, capacitance and relative permittivity) with respect to mechanical performance. Microstructure and interfacial bonding of matrix and steel fibres was observed by electron microscopy imaging. Steel fibres caused an improvement in all assessed electrical properties but only above a certain frequency values. Furthermore, steel reinforced samples exhibited increase in both compressive and flexural strength.
Improved methodology for determining tensile strength of fibre reinforced concrete
Authors: Křístek V , Vodička J , Musil L , Hanzlová H
Published: August 2019

Two configurations are currently used to determine the tensile strength of fibre reinforced concrete: simply supported beams of square cross section loaded either by two forces at thirds of spans (four-point bending test) or by one force at the mid-span where the specified cross section is weakened on the tensile side by a notch (three-point bending test). Based on elementary formulas, the tensile strength of fibre reinforced concrete is then determined. Considering the unacceptability of these formulas to capture the 3D problem and, in particular, for the three-point bending test, also because of significant singularities at the notch and the degree of statistical uncertainty in determining the actual position of the weakest area of the test specimen, such a test does not respect the real stress distribution in the tensile area which is changing in the process of load increase. The proposed adjustment of the test specimen eliminates these fundamental drawbacks by removing the singular areas of the specimen and leaving only the cross-sectional areas where only uniaxial stress state may be assumed. The results obtained by this methodology are presented, statistically evaluated and compared with the currently used procedures.
The impact of various types of steel fibres on the strength parameters and blast resistance of high – performance concrete
Authors: Bibora P , Drdlová M , Prachař V , Sviták O
Published: August 2019

The paper describes composition proposals and subsequent optimization and testing of developed fibre-reinforced UHPC mixtures, which seem to be optimal as construction material for the blast and ballistic protective systems, such as mobile blast-resistant walls and covers, which are the expected outcomes of the presented research project. Methods of laboratory testing and optimization of developed UHPC mixtures, with the aim of achieving the best possible values of physical-mechanical parameters, are described in this paper. In connection with laboratory verification, field blast tests of UHPC board samples and consequently of the entire blast-resistant wall system were realized and resistance to dynamic stress was investigated.
Material properties of various types of fibre reinforced concrete exposed to elevated temperature
Authors: Horníková K , Foglar M
Published: August 2019

This paper presents experimental program focused on determination of material properties of various types of fiber reinforced concrete exposed to elevated temperatures up to 1000° C. Material properties were measured by several methods which are described and compared. The resulting changes of material properties depending on temperature are presented. The values are compared with values from literature and standards. The aim of this paper is to provide a comprehensive overview of material properties of these types of concrete depending on elevated temperature and possibility of their measurement.
Influence of internal composition of fiber reinforced cement composites on resistance to near field blast
Authors: Zíma J , Foglar M
Published: August 2019

This paper describes the influence of internal composition of fiber reinforced cement composites on resistance to near field blast. The influence of multiple basalt meshes and dispersed fibers on a damage induced by a near-field blast is studied and numerically evaluated. Experimental measurements performed in the Boletice military area in 2014, 2015 and 2016 are evaluated by numerical simulations. The evaluation of the results is mainly focused on the stress in the cement composite, propagation of the overpressure caused by the blast and velocity of the ejected parts from the specimen. The influence of velocity of ejected parts coming out of the specimen, originally caused by the impact of a steel plate which bears TNT charges, is examined. And last, but not least, the influence of presence and position of basalt meshes in the specimen on its damage induced by delamination is also examined.
A testing method for studying the serviceability behavior of reinforced UHPFRC tensile ties
Authors: Khorami M , Navarro-Gregori J , Serna P , Navarro-Laguarda M A
Published: August 2019

Structural control under the serviceability limit state is a requirement of design codes to ensure the durability of structural elements. As it is possible to consider fibers to be reinforcement in concrete, UHPFRC can be used to guarantee properly distributing cracks and limiting crack width in the serviceability limit state. This research presents an experimental testing method for direct tensile tests on UHPFRC specimens. The results obtained from the proposed method, such as the specimen’s average tensile stress-strain curve, tensile stress in concrete, number and width of cracks, can be used to consider the behavior and design requirements of UHPFRC under serviceability conditions.
Experimental analysis of crack development of an UHPC wall element under shear loading
Authors: Příbramský V , Kopálová M , Dlouhý L
Published: August 2019

UHPC (Ultra High-Performance Concrete) is an innovative material that enables design of lightweight and structurally optimized, long-lasting structures. In this paper is presented experimental analysis of precast webs of “butterfly web” box-girder bridge on scaled-down specimens. Pretensioned beam specimens were analysed in 2 variants – with continuous web and with lightened web. Based on the experimental results are both variants compared and are presented numerical and material models suitable for UHPC modelling in software SCIA Engineer. In SCIA Engineer is implemented modified Mazarz material damage model which is applicable for material with residual strength typical for FRC and UHPFRC.
Analysis of interfacial interaction in UHPFRC-strengthened reinforced concrete beams
Authors: Zanuy C , Ulzurrun G S D , Díaz I M
Published: August 2019

The behaviour and failure mode of reinforced concrete elements strengthened with a thin tensile layer of ultra-high performance fiber-reinforced concrete (UHPFRC) is governed by the interface interaction between the UHPFRC and conventional concrete. In order to analyze the relative displacements at the interface and its influence on the crack pattern evolution and monolithic response, digital image correlation (DIC) has been used in this contribution. With the help of DIC, the distinct stages of the behaviour of UHPFRC-strengthened beams have been correlated with the crack formation and development. Special attention has been paid to the progressive debonding due to the strain incompatibility between UHPFRC and conventional concrete when cracks develop. It is shown that the utilization of the capacity of the UHPFRC can be achieved from a certain thickness of the strengthening layer for shear-critical elements, thereby providing a gain of shear strength and ductility. In contrast, a thinner UHPFRC layer has been more beneficial for flexure-critical elements.
Macro synthetic fibre reinforced concrete: Influence of the matrix mix design on interfacial bond behavior
Authors: Del Prete C , Buratti N , Manzi S , Mazzotti C
Published: August 2019

Since the composite nature of Fibre Reinforced Concrete materials, their performance is strictly dependent on the mechanical properties of their components, matrix and fibres, but, above all, on their interaction. The collaboration of the two materials is directly responsible of the force transferring mechanism from concrete to fibres that reflects their contribute in the residual flexural strength performance. This paper aims at understanding how the concrete admixture components might affect the bond of polypropylene crimped fibres, and presents the preliminary results of an experimental campaign consisting of pull-out and compression tests. Four water cement ratios and three cement-sand ratios were considered. The experimental analysis is also supported by the calibration of a numerical model that simulates the pull-out behaviour of a single fibre.
Numerical modelling of failure on brick masonry strengthened with FRCM overlays
Authors: Almeida João A P P , Pereira Eduardo B , Barros Joaquim A O
Published: August 2019

The behaviour of masonry elements under in-plane loads can be improved by using strengthening overlays. However, the changes in stiffness of the elements after strengthening may have various effects at the level of the behaviour of the entire structure. Advanced numerical simulations can be a helpful and cost effective strategy to guide the efficient design of strengthening systems. These models should simultaneously show the ability to deal with the complexities associated with the composite behaviour of panels at a smaller scale, and allow the simulation of models that can include the entire structure. A constitutive model for a 3D interface finite element, implemented in a FEM-based computer program, was applied for the simulation of the interfaces between substrate and the Fabric Reinforced Cementitious Matrix (FRCM) overlay. The mechanical behaviour of the interfaces between the different layers of the strengthened masonry elements were obtained from direct shear tests on couplet specimens. Subsequently, these results were used to define the constitutive laws of the interface elements. Finally, the numerical model developed was used to simulate the in-plane structural response of the strengthened masonry specimens.
Utilisation of date palm fibres in cement-based composites: A feasibility study
Authors: Abdelmajeed Labib Wafa
Published: August 2019

The renewed interest in the preservation of non-renewable resources has made the use of plant-based natural fibres as an environmentally friendly replacement to their synthetic counterparts in construction materials a necessity. This is due to the ability of plant-based natural fibres to enhance the mechanical properties of building components, their relatively low cost, and their derivation from a renewable resource. In this paper, the feasibility of using date palm fibres in cement composites as a replacement for synthetic fibres is reported. This study has reported on the production, types, and comparison between the chemical and mechanical properties of date palm fibres and synthetic fibres.
Experimental verification of functionality of fibre-reinforced concrete submersible piers
Authors: Buchlák J , Matějka J , Ryjáček P , Bílý P , Procházka J , Pollert J , Fabel J
Published: August 2019

Low capacity of river banks is a problem of many world cities. Extension can be realised in many ways. One of the ways is to use a system of floating piers. Usual types of piers are filled with floating material, which supports the pier for the whole lifetime. The system of piers described in this article is innovative, because it is supported by an air bag, which can be deflated and then the whole system sinks down to the bottom of the river. This can be helpful in case of danger of floods, because there will be no need to transport the piers to a secure dock. Piers are designed for easy modular connection in various groups. The main types of groups are linear and areal. This article briefly describes the design of fibre reinforced concrete pier and other support constructions which are necessary for the right function of the system. The design of the pier was verified by hydraulic experiments on models in scale 1:10 to real pier. The article contains the description and results of the experiments that have proven the system to be feasible.
Blast resistance of multi-layered concrete slabs
Authors: Fládr J , Chylík R , Šeps K , Štoller J , Trtík T
Published: August 2019

This paper compares blast resistance of multi-layered and single-layered concrete panels having different thickness and reinforcement and subjected to various explosive charges. The panels were analysed by ultrasound measurements before the application of blast loading; the velocity of transfer of ultrasound waves through the panels was determined. The same measurement was conducted after exposing the panels to contact explosion and the damage was evaluated based on the determined changes. Nine panels were tested, four of them single-layered and five of them multi-layered. The weights of Pentrite explosive charges were 150 g, 300 g and 500 g. The results show that multi-layered panels are suitable for the protection of soft targets or as cladding of load-bearing structures.
Study of boundary conditions for design of new types of fibre concrete energy dissipators in hydraulic structures
Authors: Fošumpaur P , Kašpar T , Králík M , Zukal M
Published: August 2019

The paper describes experiments aimed at setting parameters for an efficient design of new types and shapes of energy dissipators on chutes of dam spillways. During major rainfall events, large water inflows into the reservoir induce a rise in the reservoir level, and a spillway system must be installed to spill safely the flood waters. Two key challenges during the spillway design are conveyance and energy dissipation. Energy dissipation on dam spillways can be achieved by a range of dissipator designs. One type of spillway is a block ramp. Block ramps are hydraulic structures which are often used in practical applications to assure a correct balance between hydraulic functioning and the environmental impact. One of the main peculiarities of this approach is the capacity to dissipate a larger energy amount than other traditional structures. Thus, significant efforts were spent by the scientific community around the world in order to optimize their energy dissipation efficiency. The use of fibre concrete for the design of reinforced block ramps can improve their resistance significantly. The presented experiments describe the boundary condition for the design of new fibre concrete dissipators based on the measurements performed on reinforced block ramps.
Mechanisms behind radiation-induced deterioration of concrete
Authors: Khmurovska Y , Štemberk P
Published: August 2019

This paper describes the mechanism of radiation-induced deterioration of concrete and its components based on the literature review. The deterioration mechanism in different levels starting from the interaction between neutron and nucleus through the mineral metamictization and cement paste shrinkage up to the reduction of mechanical properties of concrete is explained in detail. All basic dependencies and patterns of volumetric change of minerals, aggregates, cement paste and finally concrete are also described in order to create a base for the future development of numerical models. Finally, the reduction of concrete mechanical properties is in correlation with its volumetric expansion. The radiation-induced volumetric expansion of concrete is affected by irradiation conditions (neutron fluence, neutron spectrum and temperature) and concrete composition (the amount, the proportion, the type and the structure of the minerals in the aggregate composition and the amount, the composition, the age and the structure of the cement paste).
Mechanical properties of concrete with small fibre for numerical modelling
Authors: Marcalikova Z , Prochazka L , Pesata M , Bilek V , Cajka R
Published: August 2019

The study specializes in the area of mechanical properties of select fibre reinforcement concrete. For the research fibre concrete reinforced with short steel fibres was used without bending. Fibre concrete is produced in the dosing 40 and 75 kg/m3. Laboratory program includes a complete group of tests, i.e. concrete compressive strength in cubes, three-point bending test, and split tension strength perpendicular and parallel to filling direction. Results are processed in summary, and they also include fracture-mechanical parameters needed for structural modelling. The research carried out found the positive influence of fibre on tensile strength and fracture energy. However, with more fibre, only fracture energy increases. It has also been found that the effect on compressive strength is small. For numerical modelling, the suitability of using a 3D computational model in combination with the fracture-plastic material model for fibre reinforcement concrete was verified.
Evaluation of the size effect of waste tyre rubber particles on properties of lightweight rubber concrete
Authors: Záleská M , Pavlíková M , Čítek D , Pavlík Z
Published: August 2019

Due to the increasing amount of waste tyres and also to their properties, it is necessary to look for suitable ways for their recycling. For production of rubber concrete, the crushed tyre rubber of fraction 0/4 and 4/8 was used for partial substitution of silica sand at the rate of 10 % by mass. For comparison, a reference concrete without rubber aggregate was also studied. Both natural and rubber aggregate were first assessed in terms of their physical parameters and thermal transport and storage properties. Evaluation of produced lightweight rubber concrete included measurement of basic physical properties, strength tests, and microstructural analysis. Thermal properties were studied from dry to fully water saturated state. The experimental results showed that concrete with a small amount of rubber aggregate had improved thermal insulation performance and can serve as an eco-friendly material for structural applications in civil engineering.
Using of TRC for research of crack evolution and the effect of autogenous healing
Authors: Žáková H , Žák J
Published: August 2019

Cracks in the concrete part of substructure are a problem in terms of penetration of water into the building. The best way is to prevent their development or support autogenous healing of concrete as much as possible. It is suitable to create many small specimens for research of crack evolution in various boundary conditions. TRC is applicable material for this research due to its compact dimensions and the ability to create a lot of cracks in relatively small area of the specimen. There are two basic methods how to create cracks in this material, tensile and bending loading. Each method provides different crack shapes.
At wavelength coherent scatterometry microscope using high-order harmonics for EUV mask inspection
Authors: Nagata Yutaka , Harada Tetsuo , Watanabe Takeo , Kinoshita Hiroo , Midorikawa Katsumi
Published: August 2019

In this review, we describe our research on the development of the 13.5 nm coherent microscope using high-order harmonics for the mask inspection of extreme ultraviolet (EUV) lithography. EUV lithography is a game-changing piece of technology for high-volume manufacturing of commercial semiconductors. Many top manufacturers apply EUV technology for fabricating the most critical layers of 7 nm chips. Fabrication and inspection of defect-free masks, however, still remain critical issues in EUV technology. Thus, in our pursuit for a resolution, we have developed the coherent EUV scatterometry microscope (CSM) system with a synchrotron radiation (SR) source to establish the actinic metrology, along with inspection algorithms. The intensity and phase images of patterned EUV masks were reconstructed from diffraction patterns using ptychography algorithms. To expedite the practical application of the CSM, we have also developed a standalone CSM, based on high-order harmonic generation, as an alternative to the SR-CSM. Since the application of a coherent 13.5 nm harmonic enabled the production of a high contrast diffraction pattern, diffraction patterns of sub-100 ns size defects in a 2D periodic pattern mask could be observed. Reconstruction of intensity and phase images from diffraction patterns were also performed for a periodic line-and-space structure, an aperiodic angle edge structure, as well as a cross pattern in an EUV mask.
Psychological correlates of multimorbidity and disability accumulation in older adults
Authors: Calderón-Larrañaga Amaia , Vetrano Davide Liborio , Welmer Anna-Karin , Grande Giulia , Fratiglioni Laura , Dekhtyar Serhiy
Published: August 2019

Background/Objectives

attitudes toward life and health are emerging as important psychological contributors to health heterogeneity in ageing. We aimed to explore whether different psychological factors were associated with the rate of chronic disease and disability accumulation over time.

Design

population-based cohort study between 2001 and 2010.

Setting

Swedish National study on aging and care in Kungsholmen.

Subjects

adults aged 60 and older (N = 2293).

Methods

linear mixed models were employed to study the association of life satisfaction, health outlook, resistance to illness, sickness orientation, and health worry with the rate of accumulation of chronic diseases and impaired basic and instrumental activities of daily living. Models were adjusted for demographic, clinical, social, personality and lifestyle factors. Analyses were repeated after excluding individuals with multimorbidity or disability at baseline.

Results

high life satisfaction and positive health outlook were consistently associated with a lower rate of accumulation and progression of multimorbidity (β −0.064 95% confidence interval [CI] −0.116, −0.011; β −0.065 95% CI −0.121, −0.008, respectively) and disability (β −0.063 95% CI −0.098, −0.028; β −0.042 95% CI −0.079, −0.004, respectively) over time. This was true even for people without multimorbidity or disability at baseline and after adjusting for all covariates.

Conclusions

positive attitudes toward life in general and health in particular may be especially important in old age, when the cumulative effects of biological and environmental deficits lead to accelerated health decline. These findings should encourage researchers to use measures of psychological well-being to better understand the multifactorial and diverse process of ageing.
Human Papillomavirus (HPV) 16 and 18/45 Genotyping-Directed Follow-up of Women With Messenger RNA HPV-Positive, Cytology-Negative Cervical Screening Test Results
Authors: Han Min , Li Juan , Austin Marshall , Varma Kavita R , Zhang Huina , Zhao Chengquan
Published: August 2019

Objectives

In this study, we sought to correlate genotype test results for human papillomavirus (HPV) types 16, 18, and 45 with histopathologic follow-up diagnoses in patients with messenger RNA (mRNA) high-risk HPV-positive, cytology-negative results.

Methods

We identified 1,157 patients with mRNA HPV-positive, cytology-negative cervical screening test results between June 2015 and June 2018. Reflex HPV 16/18/45 genotype results were documented in 1,018 women aged 30 years or older, 318 of whom had follow-up within 18 months.

Results

Histopathologic findings of cervical intraepithelial neoplasia 2 or worse (CIN2+) were diagnosed in 14 of 122 (11.5%) patients positive for HPV 16/18/45 vs in seven of 196 (3.6%) HPV 16/18/45–negative patients. Three patients with high-risk HPV–positive, cytology-negative cervical screening test results were diagnosed with stage I cervical adenocarcinomas following early colposcopic referral and biopsy after HPV 16/18/45–positive genotype results.

Conclusions

Immediate reflex HPV 16/18/45 genotyping of mRNA HPV-positive, cytology-negative patients led to early colposcopic referral and histopathologic diagnoses of three difficult-to-detect, low-stage, cervical adenocarcinomas and significantly increased overall early detection of CIN2+ lesions.
A Bayesian Sensitivity Analysis to Partition Body Mass Index Into Components of Body Composition: An Application to Head and Neck Cancer Survival
Authors: Bradshaw Patrick T , Zevallos Jose P , Wisniewski Kathy , Olshan Andrew F
Published: August 2019

Previous studies have suggested a “J-shaped” relationship between body mass index (BMI, calculated as weight (kg)/height (m)2) and survival among head and neck cancer (HNC) patients. However, BMI is a vague measure of body composition. To provide greater resolution, we used Bayesian sensitivity analysis, informed by external data, to model the relationship between predicted fat mass index (FMI, adipose tissue (kg)/height (m)2), lean mass index (LMI, lean tissue (kg)/height (m)2), and survival. We estimated posterior median hazard ratios and 95% credible intervals for the BMI-mortality relationship in a Bayesian framework using data from 1,180 adults in North Carolina with HNC diagnosed between 2002 and 2006. Risk factors were assessed by interview shortly after diagnosis and vital status through 2013 via the National Death Index. The relationship between BMI and all-cause mortality was convex, with a nadir at 28.6, with greater risk observed throughout the normal weight range. The sensitivity analysis indicated that this was consistent with opposing increases in risk with FMI (per unit increase, hazard ratio = 1.04 (1.00, 1.08)) and decreases with LMI (per unit increase, hazard ratio = 0.90 (0.85, 0.95)). Patterns were similar for HNC-specific mortality but associations were stronger. Measures of body composition, rather than BMI, should be considered in relation to mortality risk.
What is Machine Learning? A Primer for the Epidemiologist
Authors: Bi Qifang , Goodman Katherine E , Kaminsky Joshua , Lessler Justin
Published: August 2019

Machine learning is a branch of computer science that has the potential to transform epidemiologic sciences. Amid a growing focus on “Big Data,” it offers epidemiologists new tools to tackle problems for which classical methods are not well-suited. In order to critically evaluate the value of integrating machine learning algorithms and existing methods, however, it is essential to address language and technical barriers between the two fields that can make it difficult for epidemiologists to read and assess machine learning studies. Here, we provide an overview of the concepts and terminology used in machine learning literature, which encompasses a diverse set of tools with goals ranging from prediction to classification to clustering. We provide a brief introduction to 5 common machine learning algorithms and 4 ensemble-based approaches. We then summarize epidemiologic applications of machine learning techniques in the published literature. We recommend approaches to incorporate machine learning in epidemiologic research and discuss opportunities and challenges for integrating machine learning and existing epidemiologic research methods.
Complement Components sC5b-9 and CH50 Predict Prognosis in Heart Failure Patients Combined With Hypertension
Authors: Wang Wenyuan , Cai Dinghua
Published: August 2019

BACKGROUND

Heart failure (HF), resulting from inflammation and vessel injury, is one of the leading causes of poor quality of life and premature death. The complement system plays a leading role in vessel integrity and inflammation response. However, the association between serum complement level and the prognosis of HF remains unclear.

METHODS

In our study, a total of 263 newly diagnosed hypertension patients with HF were included. Eight classical cardiovascular risk factors were collected, and plasma C3a, C3b, C5a, sC5b-9, and CH50 levels were detected.

RESULTS

Compared with the control group, plasma C5a (P<0.001), sC5b-9 (P<0.001), and CH50 (P = 0.004) levels of hypertension patients with HF were significantly increased. On the basis of univariate analysis, an older age, higher frequency of alcohol consumption, high level of body mass index, medium or high risk of hypertension, hyperlipidemia, and diabetes were poor prognostic factors whereas low levels of C5a, sC5b-9, and CH50 were associated with favorable overall survival (OS). When these factors fit into a multivariate regression model, patients with hyperlipidemia (P = 0.002, hazard ratio [HR] = 3.09), N-terminal pro-Brain Natriuretic Peptide (NT-pro-BNP) ≥ 14.8 (P < 0.001, HR = 11.14), sC5b-9 level ≥ 1,406.2 µg/ml (P = 0.180, HR = 5.51) or CH50 level ≥ 294.6 µg/ml (P < 0.001, HR = 4.57) remained statistically factors for worsened OS and regarded as independent risk factors. These independently associated risk factors were used to form an OS estimation nomogram. Nomogram demonstrated good accuracy in estimating the risk, with a bootstrap-corrected C index of 0.789.

CONCLUSIONS

sC5b-9 and CH50 levels are increased in hypertension patients with HF. Nomogram based on multivariate analysis has good accuracy in estimating the risk of OS.
Reward, Relief and Habit Drinking: Initial Validation of a Brief Assessment Tool
Authors: Grodin Erica N , Bujarski Spencer , Venegas Alexandra , Baskerville Wave-Ananda , Nieto Steven J , Jentsch J David , Ray Lara A
Published: August 2019

Aims

Alcohol use disorder is highly heterogeneous. One approach to understanding this heterogeneity is the identification of drinker subtypes. A candidate classification consists of reward and relief subtypes. The current study examines a novel self-report measure of reward, relief, and habit drinking for its clinical correlates and subjective response (SR) to alcohol administration.

Methods

Non-treatment-seeking heavy drinkers (n = 140) completed the brief reward, relief, habit drinking scale (RRHDS). A subset of this sample (n = 67) completed an intravenous alcohol administration. Individuals were classified into drinker subtypes. A crowdsourced sample of heavy drinkers (n = 187) completed the RRHDS and a validated reward relief drinking scale to compare drinking classification results.

Results

The majority of the sample was classified as reward drinkers (n = 100), with fewer classified as relief (n = 19) and habit (n = 21) drinkers. Relief and habit drinkers reported greater tonic alcohol craving compared to reward drinkers. Reward drinkers endorsed drinking for enhancement, while relief drinkers endorsed drinking for coping. Regarding the alcohol administration, the groups differed in negative mood, such that relief/habit drinkers reported a decrease in negative mood during alcohol administration, compared to reward drinkers. The follow-up crowdsourcing study found a 62% agreement in reward drinker classification between measures and replicated the tonic craving findings.

Conclusions

Our findings suggest that reward drinkers are dissociable from relief/habit drinkers using the brief measure. However, relief and habit drinkers were not successfully differentiated, which suggests that these constructs may overlap phenotypically. Notably, measures of dysphoric mood were better at detecting group differences than measures capturing alcohol’s rewarding effects.
Fitness costs of delayed pollination in a mixed-mating plant
Authors: Hildesheim Laura S , Opedal Øystein H , Armbruster W Scott , Pélabon Christophe
Published: August 2019

Background and Aims

To predict the evolutionary consequences of pollinator declines, we need to understand the evolution of delayed autonomous self-pollination, which is expected to evolve as a mechanism of reproductive assurance when cross-pollination becomes unreliable. This involves estimating the costs of increased levels of selfing as well as those associated with floral senescence.

Methods

We studied the mechanisms and costs of delayed self-pollination in the mixed-mating vine Dalechampia scandens (Euphorbiaceae) by first assessing among-population variation in herkogamy and dichogamy, which together determine the rate and timing of autonomous self-pollination. We then tested whether floral longevity responds plastically to delayed pollination. Finally, we assessed the costs of delayed self-pollination in terms of seed number and size, explicitly separating inbreeding depression from effects of floral senescence.

Key Results

Herkogamy varied extensively, while variation in dichogamy was more limited. Unpollinated blossoms increased their longevity, but seed quantity and quality decreased with increasing delays in pollination, independently of inbreeding depression.

Conclusions

In D. scandens, earlier autonomous selfing is facilitated by reduced herkogamy rather than reduced protogyny, providing reproductive assurance while maintaining the possibility for outcrossing events. Effective early autonomous self-pollination may evolve under reduced cross-pollination reliability in response to costs associated with floral senescence.
‘I Was Surprised to See You in a Chinese School’: Researching Multilingually Opportunities and Challenges in Community-Based Research
Authors: Ganassin Sara , Holmes Prue
Published: August 2019

Researchers working in multilingual contexts must draw on their own linguistic resources when conceptualizing, planning, conducting, and reporting their studies, whether for theses or publications, or in dissemination to other stakeholders. However, these multilingual processes have received little attention in previous research. Drawing on an ethnographic study undertaken by Sara Ganassin in Chinese community language education, we investigate what opportunities and challenges a ‘researching multilingually’ perspective offers the researcher. We analyse narrative data and ethnographic observations to illustrate how the researcher drew on her multilingual resources vis-a-vis the linguistic spaces of her research context, the reflexive aspects of her multilingual positionality, and the ethical choices faced by her. From these insights, we make a theoretical and methodological case for embedding a researching multilingually approach in research that recognizes the linguistic resources of the researcher. The study has implications for building researcher capacity in multilingual research contexts, and for highlighting multilingual researcher processes that improve understanding, reporting, and representation of people from diverse linguistic and cultural horizons.
Optimization of in silico tools for predicting genetic variants: individualizing for genes with molecular sub-regional stratification
Authors: Tang Bin , Li Bin , Gao Liang-Di , He Na , Liu Xiao-Rong , Long Yue-Sheng , Zeng Yang , Yi Yong-Hong , Su Tao , Liao Wei-Ping
Published: August 2019

Genes are unique in functional role and differ in their sensitivities to genetic defects, but with difficulties in pathogenicity prediction. This study attempted to improve the performance of existing in silico algorithms and find a common solution based on individualization strategy. We initiated the individualization with the epilepsy-related SCN1A variants by sub-regional stratification. SCN1A missense variants related to epilepsy were retrieved from mutation databases, and benign missense variants were collected from ExAC database. Predictions were performed by using 10 traditional tools with stepwise optimizations. Model predictive ability was evaluated using the five-fold cross-validations on variants of SCN1A, SCN2A, and KCNQ2. Additional validation was performed in SCN1A variants of damage-confirmed/familial epilepsy. The performance of commonly used predictors was less satisfactory for SCN1A with accuracy less than 80% and varied dramatically by functional domains of Nav1.1. Multistep individualized optimizations, including cutoff resetting, domain-based stratification, and combination of predicting algorithms, significantly increased predictive performance. Similar improvements were obtained for variants in SCN2A and KCNQ2. The predictive performance of the recently developed ensemble tools, such as Mendelian clinically applicable pathogenicity, combined annotation-dependent depletion and Eigen, was also improved dramatically by application of the strategy with molecular sub-regional stratification. The prediction scores of SCN1A variants showed linear correlations with the degree of functional defects and the severity of clinical phenotypes. This study highlights the need of individualized optimization with molecular sub-regional stratification for each gene in practice.
AntiHIV-Pred: web-resource for in silico prediction of anti-HIV/AIDS activity
Authors: Stolbov Leonid , Druzhilovskiy Dmitry , Rudik Anastasia , Filimonov Dmitry , Poroikov Vladimir , Nicklaus Marc
Published: August 2019

Motivation

Identification of new molecules promising for treatment of HIV-infection and HIV-associated disorders remains an important task in order to provide safer and more effective therapies. Utilization of prior knowledge by application of computer-aided drug discovery approaches reduces time and financial expenses and increases the chances of positive results in anti-HIV R&D. To provide the scientific community with a tool that allows estimating of potential agents for treatment of HIV-infection and its comorbidities, we have created a freely-available web-resource for prediction of relevant biological activities based on the structural formulae of drug-like molecules.

Results

Over 50 000 experimental records for anti-retroviral agents from ChEMBL database were extracted for creating the training sets. After careful examination, about seven thousand molecules inhibiting five HIV-1 proteins were used to develop regression and classification models with the GUSAR software. The average values of R2 = 0.95 and Q2 = 0.72 in validation procedure demonstrated the reasonable accuracy and predictivity of the obtained (Q)SAR models. Prediction of 81 biological activities associated with the treatment of HIV-associated comorbidities with 92% mean accuracy was realized using the PASS program.

Availability and implementation

Freely available on the web at http://www.way2drug.com/hiv/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Distinct preterm labor phenotypes have unique inflammatory signatures and contraction associated protein profiles†
Authors: Singh Natasha , Herbert Bronwen , Sooranna Gavin , Das Anya , Sooranna Suren R , Yellon Steven M , Johnson Mark R
Published: August 2019

Preterm labor (PTL) is the predominant cause of childhood morbidity and mortality. It has several phenotypes, each with a distinct etiology often involving inflammation. Here, in samples of reproductive tissues obtained in early PTL from women with phenotypically defined PTL, we examined the presence and distribution of inflammation and its relationship with prolabor gene expression. In chorioamnionitis (CA-PTL), cytokine protein concentrations were increased across all tissues; in idiopathic (I-PTL), the inflammatory changes were limited to the choriodecidua; inflammation was not a feature of placental abruption (PA-PTL). CA-PTL was associated with activation of p65 in the myometrium and AP-1 in the choriodecidua, and PA-PTL with CREB in the choriodecidua. In the myometrium, PGHS-2 mRNA level was increased in CA- and I-PTL; in the amnion, PGHS-2 mRNA level was higher in PA- and I-PTL, while in CA-PTL, OT, OTR mRNA, and CX-43 expression were increased. In the choriodecidua, PGHS-2 mRNA level was unchanged, but in CA and I-PTL, OT mRNA level were increased and OTR was reduced. These data show that CA-PTL is associated with widespread inflammation and prolabor gene expression. In contrast, in I-PTL, inflammation is limited to the choriodecidua, with discrete increases in PGHS-2 in the amnion and OT in the choriodecidua. Inflammation is not a feature of PA-PTL, which is associated with increased OT and OTR in the amnion.
Reasons for Staying: A Longitudinal Study of Work Conditions Predicting Social Workers’ Willingness to Stay in Their Organisation
Authors: Astvik Wanja , Welander Jonas , Larsson Robert
Published: August 2019

Extensive staff turnover within the statutory social services is a serious problem in Sweden and in other European countries. This study examines which work conditions predict social workers’ willingness to stay in their organisation. A web-based questionnaire was used to gather data. The participating social workers responded to two questionnaires over a one-year period. To identify the social workers who wanted to stay and also remained in the organisation, the group ‘Stayers’ (n = 1,368) consisted of social workers who reported low intentions to quit at T1. The group ‘Leavers’ (n = 1,182) were social workers who had actually resigned at T2. The data were analysed using univariate and multivariate logistic regression analyses. The multivariate analysis shows that the work conditions that predicted staying in the organisation were low degrees of conflicting demands and quantitative demands, high degrees of openness and human resource orientation in the organisation and a high degree of perceived service quality. The results are discussed in relation to public management and managerial responsibility to create sustainable work conditions that facilitate the provision of good social services for citizens.
Synergistic anti-breast cancer effect of pulsatilla saponin D and camptothecin through interrupting autophagic–lysosomal function and promoting p62-mediated ubiquitinated protein aggregation
Authors: Wang Kai , Tu Yanbei , Wan Jian-Bo , Chen Meiwan , He Chengwei
Published: August 2019

Autophagy is an evolutionarily conserved mechanism to protect the cells from unfavorable environmental conditions. Inhibition of autophagy has been contemplated as a novel strategy to enhance anticancer efficacy of existing chemotherapeutic agents. We previously reported that pulsatilla saponin D (PSD) was a potent autophagy inhibitor. However, its anticancer potential as adjuvant and underlying mechanisms are still unknown. In this study, we identified that PSD induced the formation of autophagosome in MCF-7 and MDA-MB-231 breast cancer cells. However, PSD alone and particularly co-treatment with camptothecin remarkably increased p62 protein levels, indicating that PSD strongly inhibited the autophagic cargo degradation. The mechanistic study indicated that PSD profoundly abolished the co-localization of EGFP-LC3 and lysosomal-specific probe LysoTracker Red, suggesting that the autophagosome–lysosome fusion was blocked by PSD, which is similar to the action of chloroquine. In addition, PSD significantly increased lysosomal pH and inhibited the activation of lysosomal cathepsins in both breast cancer cell lines. Furthermore, the accrued p62 resulted in accumulation of ubiquitinated proteins owing to the interaction with p62 and delivery to the malfunctioned autophagosome by PSD. Finally, we demonstrated that PSD synergistically enhanced the anticancer activity of camptothecin (CPT) in cultured breast cancer cells and in mouse xenograft tumor models. Our results indicated that PSD inhibited autophagic flux via blocking autophagosome–lysosome fusion and lysosomal acidification, which may confer a synergistic anti-breast cancer activity of PSD and CPT.
Neural Dynamics of Associative Learning during Human Sleep
Authors: Canales-Johnson Andrés , Merlo Emiliano , Bekinschtein Tristan A , Arzi Anat
Published: August 2019

Recent evidence indicates that humans can learn entirely new information during sleep. To elucidate the neural dynamics underlying sleep-learning, we investigated brain activity during auditory–olfactory discriminatory associative learning in human sleep. We found that learning-related delta and sigma neural changes are involved in early acquisition stages, when new associations are being formed. In contrast, learning-related theta activity emerged in later stages of the learning process, after tone–odor associations were already established. These findings suggest that learning new associations during sleep is signaled by a dynamic interplay between slow-waves, sigma, and theta activity.