bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dental caries vaccine: are we there yet?
Authors: Patel M. 
Published: September 2019

Abstract
Dental caries, caused by Streptococcus mutans, is a common infection. Caries vaccine has been under investigation for the last 40 years. Many in vitro and in vivo studies and some human clinical trials have determined many pertinent aspects regarding vaccine development. The virulence determinants of Strep. mutans, such as Ag I/II, responsible for adherence to surfaces, glucosyltransferase, responsible for the production of glucan, and the glucan-binding protein, responsible for the attachment of glucan to surfaces, have been known to elicit an antigen-specific immune response. It is also known that more than one antigen or a functional part of the genome responsible for these virulence determinants provide a better host response compared with the monogenic vaccine or complete genome of a specific antigen. To enhance the host response, the use of adjuvants has been studied and the routes of antigen administration have been investigated. In recent years, some promising vaccines such as pGJA-P/VAX, LT derivative/Pi39-512, KFD2-rPAc and SBR/GBR-CMV-nirB have been developed and tested in animals. New virulence targets need to be explored. Multicentre collaborative studies and human clinical trials are required and some interest from funders and public health experts should be generated to overcome this hurdle.

Significance and Impact of the Study
Dental caries is an irreversible, multifactorial opportunistic infection. The treatment is costly, making it a public health problem. Despite many years of promising laboratory research, animal studies and clinical trials, there is no commercially available vaccine today. The research objectives have become more refined from lessons learnt over the years. Multigenic DNA/recombinant vaccines, using the best proved adjuvants with a delivery system for the nasal or sublingual route, should be developed and researched with multicentre collaborative efforts. In addition, new vaccine targets can be identified. To overcome the economic hurdle, funders and public health interest should be stimulated.
High prevalence of occult hepatitis B infection (OBI) among healthy children and their parents in Alborz province, Iran; Vertical OBI, myth or truth?
Authors: Ghaziasadi Azam , Fakhari Zahra , Aghcheli Bahman , Poortahmasebi Vahdat , Farahmand Mohammad , Norouzi Mehdi , Ghalichi Leila , Soleimani Alireza , Hedayat Yaghoobi Mojtaba , Ravanshad Mehrdad , Jazayeri Seyed Mohammad 
Published: September 2019

AbstractBackgroundOccult hepatitis B infection (OBI) has been described in various clinical settings including after hepatitis B virus (HBV) immunization. The purpose of study was to characterize the prevalence of OBI among immunized children from a subset of general population and the parents of OBI‐positive cases.MethodsSera of 1200 children from general population who have been previously immunized by HBV vaccine were assayed for anti‐HBs. 660 were randomly selected for HBV DNA testing by different polymerase chain reaction (PCR) methods and were analysed by direct sequencing on surface genes.ResultsNone of participants were positive for HBsAg and anti‐HBc. 549 (45.7%) and 651 (54.3%) cases had anti‐HBs > 10 mIU/mL (responders) and < 10 mIU/mL (nonresponders) respectively. Of 660 selected specimens, 91 (16%) of children were positive for OBI. 23 (25.2%) and 68 (74.8%) of HBV DNA positive cases were belonged to responders and nonresponders, respectively, showing significant difference (P < .001). The mean levels of anti‐HBs in OBI‐positive and OBI‐negative groups, showed no considerable variations. The mean viral load for OBI‐positive cases showed substantial differences between responders and nonresponders (P = .007). Of 49 parents (98 individuals) of OBI‐positive children 11 (22%) and 18 (36%) were positive for anti‐HBc and anti‐HBs respectively. Molecular testing was positive in 32 subjects (16 couples, 32.6%). In total, 6 mothers and 11 fathers were positive for OBI.ConclusionA proportion of OBI‐positive vaccinated children could be existed in different populations. This finding could be arisen from vertical HBV transmission or vertical OBI possibly from their parents.
Disparities between Aboriginal and non‐Aboriginal perinatal mortality rates in Western Australia from 1980 to 2015
Authors: Adane Akilew A. , Bailey Helen D. , Marriott Rhonda , Farrant Brad M. , White Scott W. , Stanley Fiona J. , Shepherd Carrington C. J. 
Published: September 2019

AbstractBackgroundPerinatal mortality rates are typically higher in Aboriginal than non‐Aboriginal populations of Australia.ObjectivesThis study aimed to examine the pattern of stillbirth and neonatal mortality rate disparities over time in Western Australia, including an evaluation of these disparities across gestational age groupings.MethodsAll singleton births (≥20 weeks gestation) in Western Australia between 1980 and 2015 were included. Linked data were obtained from core population health datasets of Western Australia. Stillbirth and neonatal mortality rates and percentage changes in the rates over time were calculated by Aboriginal status and gestational age categories.ResultsFrom 1980 to 2015, data were available for 930 926 births (925 715 livebirths, 5211 stillbirths and 2476 neonatal deaths). Over the study period, there was a substantial reduction in both the Aboriginal (19.6%) and non‐Aboriginal (32.3%) stillbirth rates. These reductions were evident in most gestational age categories among non‐Aboriginal births and in Aboriginal term births. Concomitantly, neonatal mortality rates decreased in all gestational age windows for both populations, ranging from 32.1% to 77.5%. The overall stillbirth and neonatal mortality rate differences between Aboriginal and non‐Aboriginal birth decreased by 0.6 per 1000 births and 3.9 per 1000 livebirths, respectively, although the rate ratios (RR 2.51, 95% CI 2.14, 2.94) and (RR 2.94, 95% CI 2.24, 3.85), respectively reflect a persistent excess of Aboriginal perinatal mortality across the study period.ConclusionsDespite steady improvements in perinatal mortality rates in Western Australia over 3½ decades, the gap between Aboriginal and non‐Aboriginal rates remains unchanged in relative terms. There is a continuing, pressing need to address modifiable risk factors for preventable early mortality in Aboriginal populations.
Genotypic diversity and acidogenicity of Streptococcus mutans in Down syndrome children
Authors: Moreira Maurício José Santos , Klaus Natália Mincato , Dall'Onder Ana Paula , Grando Débora , Parolo Clarissa Cavalcanti Fatturi , Faccini Lavinia Schuler , Hashizume Lina Naomi 
Published: September 2019

AbstractAimsTo evaluate the genotypic diversity and acidogenicity of Streptococcus mutans (S. mutans) and the potential association of these factors with dental caries experience in children with DS compared to non‐DS children (controls).Methods and resultsSeventeen children (age 6‐12 years) with high salivary S. mutans counts (> 2.5 × 105 CFU/mL) were selected and divided into two groups: DS and non‐DS. Five children in each group were caries‐free, while the remainder had elevated caries experience. S. mutans isolates were obtained from each participant. The genotypic profile of the isolates was analyzed with the AP‐PCR methodology. The acidogenicity of a representative strain from each genotype of S. mutans was also evaluated. DS children had 16 different S. mutans genotypes, while the control group had 21. Twelve genotypes were present in both groups and one of them was associated with caries‐free status (P < .05). Although the acidogenicity of the genotypes found in DS children was significantly lower (P < .05) compared to controls, this fact was not associated with caries experience in both groups.ConclusionsDS children have a lower S. mutans genotypic diversity and genotypes with lower acidogenicity than those of non‐DS children. However these findings were not associated with their caries experience.
Spatial housing market polarisation: National and urban dynamics of diverging house values
Authors: Hochstenbach Cody , Arundel Rowan 
Published: September 2019

AbstractHousing is central in the reproduction of social inequalities. Beyond divides across populations, trends point to increasingly unequal housing‐market dynamics across space. Nonetheless, little systematic evidence exists on the spatial inequality of housing values. In this paper we address this through a detailed investigation of house‐value developments in the Netherlands over time and space. We draw on national registers including longitudinal and geocoded data for the entire housing stock over the 2006–2018 period. Spatial polarisation is examined across different scales at the national, provincial, and urban level. We further investigate how housing‐market inequality trends vary over time, particularly between periods of economic boom and house‐price increases or, conversely, periods of downturn. Our analyses expose a substantial and widespread trend of spatial polarisation. Rising spatial inequality between neighbourhoods is clearly apparent at the national level, within all but one province, as well as for 44 of the 50 largest municipalities. The polarising trend appears structural and pervasive. While boom periods saw the strongest increases, inequality levels, remarkably, remained stable or even saw continued increases over the period of declining house prices. These patterns of spatial polarisation in house values have fundamental societal implications towards uneven wealth accumulation and in amplifying socio‐economic cleavages across populations and space.
The effects of bilateral attitudes on imports
Authors: Bao Xiaohua , Liu Qing , Qiu Larry D. , Zhu Daming 
Published: September 2019

AbstractResearch based on the gravity model has shown that non‐economic factors affect international trade, and recent studies have shown that people's perception affects economic exchange. In this study, we explore the effects of attitudes on bilateral trade. Using survey data from the Pew Research Center's Global Attitudes Projects for 68 countries from 2002 to 2015, we find that a more favourable attitude of a country towards another country will increase the former country's imports from the latter. The result is robust to an endogeneity check, to different measures of attitudes and to different estimation methods. However, heterogeneity is observed across different types of goods and countries. The result holds for trade in intermediate and consumer goods, but the effects are not statistically significant for capital goods. The effects are statistically significant for bilateral trade between different country groups, except for high‐income countries' imports from non‐high‐income countries.
A Boiti-Leon Pimpinelli equations with time-conformable derivative
Authors: Touchent Kamal Ait , Hammouch Zakia , Mekkaoui Toufik , Unlu Canan 
Published: September 2019

In this paper, we derive some new soliton solutions to $(2+1)$-Boiti-Leon Pempinelli equations with conformable derivative by using an expansion technique based on the Sinh-Gordon equation. The obtained solutions have different expression such as trigonometric, complex and hyperbolic functions. This powerful and simple technique can be used to investigate solutions of other nonlinear partial differential equations.
An Innovative Ex Vivo Vascular Bioreactor as Comprehensive Tool to Study the Behavior of Native Blood Vessels Under Physiologically Relevant Conditions
Authors: Vanerio Noemi , Stijnen Marco , de Mol Bas A. J. M. , Kock Linda M. 
Published: September 2019

Abstract
Ex vivo systems represent important models to study vascular biology and to test medical devices, combining the advantages of in vitro and in vivo models such as controllability of parameters and the presence of biological response, respectively. The aim of this study was to develop a comprehensive ex vivo vascular bioreactor to long-term culture and study the behavior of native blood vessels under physiologically relevant conditions. The system was designed to allow for physiological mechanical loading in terms of pulsatile hemodynamics, shear stress, and longitudinal prestretch and ultrasound imaging for vessel diameter and morphology evaluation. In this first experience, porcine carotid arteries (n = 4) from slaughterhouse animals were cultured in the platform for 10 days at physiological temperature, CO2 and humidity using medium with blood-mimicking viscosity, components, and stability of composition. As expected, a significant increase in vessel diameter was observed during culture. Flow rate was adjusted according to diameter values to reproduce and maintain physiological shear stress, while pressure was kept physiological. Ultrasound imaging showed that the morphology and structure of cultured arteries were comparable to in vivo. Histological analyses showed preserved endothelium and extracellular matrix and neointimal tissue growth over 10 days of culture. In conclusion, we have developed a comprehensive pulsatile system in which a native blood vessel can be cultured under physiological conditions. The present model represents a significant step toward ex vivo testing of vascular therapies, devices, drug interaction, and as basis for further model developments.
Effect of Noise and Nonlinearities on Thermoacoustics of Can-Annular Combustors
Authors: Ghirardo G. , Moeck J. P. , Bothien M. R. 
Published: September 2019

Abstract
Can-annular combustors consist of N distinct cans setup symmetrically around the axis of the gas turbine. Each can is connected to the turbine inlet by means of a transition duct. At the turbine inlet, a small gap between the neighboring transition ducts allows acoustic communication between the cans. Thermoacoustic pulsations in the cans are driven by the respective flames, but also the communication between neighboring cans through the gap plays a significant role. In this study, we focus on the effect of the background noise intensity and of the nonlinear flame saturation. We predict how usually clusters of thermoacoustic modes are unstable in the linear regime and compete with each other in the nonlinear regime, each cluster consisting of axial, azimuthal and push-pull modes. Since linear theory cannot predict the nonlinear solution, stochastic simulations are run to study the nonlinear solution in a probabilistic sense. One outcome of these simulations is the various pulsation patterns, which are in principle different from one can to the next. We recover how not only a stronger flame response in one can gives rise to the phenomenon of mode localization, but also how the nonlinearity of the flame saturation and the competition between modes have an effect on the nonlinear mode shape. We finally predict the coherence and phase between cans on the linearized system subject to noise, and compare the predictions with engine measurements, in terms of spectra of amplitude in each can and coherence and phase, observing a good match.
Design and Performance Study of a Novel Minimally Invasive Active Surgical Needle
Authors: Varnamkhasti Zahra Khashei , Konh Bardia 
Published: September 2019

Abstract
Many medical treatments such as brachytherapy, thermal ablation, and biopsy are performed using percutaneous needle-based procedures. The success of these procedures highly depends on accurate placement of the needle tip at target positions. A novel active needle was designed and developed in this work that can steer inside the tissue via a shape memory alloy (SMA) actuator attached to its body. With actuation and control offered by the actuator, the active needle can reach the target positions with more accuracy, and thereby potential improvement in clinical outcomes. An integrated system was also developed to robotically operate the active needle insertion. The performance of the active needle was evaluated with finite element methods and experimental tests on a fabricated prototype in air. Active needle insertion tests in a tissue phantom were also performed to evaluate the performance of the active needle. The deflection in air and tissue phantom demonstrated the capability of the active needle to reach target positions.
Steady and Transient Behavior of Cross-Flow Three-Fluid Heat Exchanger With Temperature Nonuniformity in All the Fluids—A Detailed Investigation
Authors: Aasi Harpreet Kaur , Mishra Manish 
Published: September 2019

Abstract
Cross-flow three-fluid plate-fin heat exchanger is analyzed under both steady-state and transient conditions with a nonuniform inlet temperature of all the three fluids. The influence of the longitudinal heat conduction and axial dispersion in the separating sheets and three fluids, respectively, is also considered. Five different combinations (modes) of temperature nonuniformity in the three fluids have been considered and compared for the performance. An important phenomenon of temperature cross between/among the fluids has been observed and presented for certain modes of temperature nonuniformity and operating conditions. The effect in the performance has been presented on the basis of mean exit temperature and deterioration factor. Implicit finite difference technique has been used for the numerical solution. The heat exchanger's performance is found to be dependent on the mode of temperature nonuniformity, number of transfer units, and the operating parameters.
When the Joukowsky Equation Does Not Predict Maximum Water Hammer Pressures
Authors: Walters Trey W. , Leishear Robert A. 
Published: September 2019

Abstract
The Joukowsky equation has been used as a first approximation for more than a century to estimate water hammer pressure surges. However, this practice may provide incorrect, nonconservative, pressure calculations under several conditions. These conditions are typically described throughout fluid transient text books, but a consolidation of these issues in a brief paper seems warranted to prevent calculation errors in practice and to also provide a brief understanding of the limits and complexities of water hammer equations. To this end, various issues are discussed here that result in the calculation of pressures greater than those predicted by the Joukowsky equation. These conditions include reflected waves at tees, changes in piping diameter, and changes in pipe wall material, as well as frictional effects referred to as line pack, and the effects due to the collapse of vapor pockets. In short, the fundamental goal here is to alert practicing engineers of the cautions that should be applied when using the Joukowsky equation as a first approximation of fluid transient pressures.
Condition Monitoring of Wind Turbine Planetary Gearboxes Under Different Operating Conditions
Authors: Mauricio Alexandre , Sheng Shuangwen , Gryllias Konstantinos 
Published: September 2019

Abstract
Digitally enhanced services for wind power could reduce operations and maintenance costs as well as the levelized cost of energy. Therefore, there is a continuous need for advanced monitoring techniques, which can exploit the opportunities of internet of things and big data analytics, revolutionizing the future of the energy sector. The heart of wind turbines is a rather complex epicyclic gearbox. Among others, extremely critical gearbox components, which are often responsible for machinery stops, are the rolling element bearings. The vibration signatures of bearings are rather weak compared to other components, such as gears, and as a result, an extended number of signal processing techniques and tools have been proposed during the last decades, focusing toward accurate, early, and on time bearing fault detection with limited false alarms and missed detections. Envelope analysis is one of the most important methodologies, where an envelope of the vibration signal is estimated usually after filtering around a frequency band excited by impacts due to the bearing faults. Different tools, such as Kurtogram, have been proposed in order to accurately select the optimum filter parameters (center frequency and bandwidth). Cyclic spectral correlation (CSC) and cyclic spectral coherence (CSCoh), based on cyclostationary analysis, have been proved as very powerful tools for condition monitoring. The monitoring techniques seem to have reached a mature level in case a machinery operates under steady speed and load. On the other hand, in case the operating conditions change, it is still unclear whether the change of the monitoring indicators is due to the change of the health of the machinery or due to the change of the operating parameters. Recently, the authors have proposed a new tool called improved envelope spectrum via feature optimization-gram (IESFOgram), which is based on CSCoh and can automatically select the filtering band. Furthermore, the CSCoh is integrated along the selected frequency band leading to an improved envelope spectrum (IES). In this paper, the performance of the tool is evaluated and further extended on cases operating under different speeds and different loads. The effectiveness of the methodology is tested and validated on the National Renewable Energy Laboratory (NREL) wind turbine gearbox vibration condition monitoring benchmarking dataset, which includes various faults with different levels of diagnostic complexity as well as various speed and load operating conditions.
Fan Flow Field in an Installed Variable Pitch Fan Operating in Reverse Thrust for a Range of Aircraft Landing Speeds
Authors: Rajendran David John , Pachidis Vassilios 
Published: September 2019

Abstract
The installed flow field for a variable pitch fan (VPF) operating in reverse thrust for the complete aircraft landing run is described in this paper. To do this, a VPF design to generate reverse thrust by reversing airflow direction is developed for a representative 40,000 lbf modern high bypass ratio engine. Thereafter, to represent the actual flow conditions that the VPF would face, an engine model that includes the nacelle, core inlet splitter, outlet guide vanes, bypass nozzle, core exhaust duct, aft-body plug, and core nozzle is designed. The engine model with the VPF is attached to a representative airframe in landing configuration to include the effects of installation. A rolling ground plane that mimics the runway during the landing run is also included to complete the model definition. Three-dimensional (3D) Reynolds-averaged Navier–Stokes (RANS) solutions are carried out for two different VPF stagger angle settings and rotational speeds to obtain the fan flow field. The dynamic installed VPF flow field is characterized by the interaction of the freestream and the reverse stream flows. The two streams meet in a shear layer in the fan passages and get deflected radially outward before turning back onto themselves. The flow field changes with stagger setting, fan rotational speed, and the aircraft landing speed because of the consequent changes in the momentum of the two streams. The description of the installed VPF flow field as generated in this study is necessary to (a) qualify VPF designs that are typically designed by considering only the uninstalled static flow field and (b) choose the VPF operating setting for different stages of the aircraft landing run.