bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonuniform Kelvin Force Effect on Laminar Flow of Nanomaterials
Authors: Jafaryar M. , Sheikholeslami M. , Arabkoohsar A. , Shafee Ahmad
Published: August 2020

In the current study, Kelvin force as an external source has been used to affect the ferrofluid flow style. The presence of wire below the pipe creates a variable magnetic force that generates rotating eddies near the wire inside the pipe. To augment the cooling rate, the type of operating fluid changes from pure water to Fe3O4-water ferrofluid. Laminar flow was studied with involving homogeneous model for the ferrofluid. A new term was added to momentum equations as Kelvin force due to the gradient of the magnetic field. Impacts of magnetic number (Mn), the fraction of ferrofluid (φ), and Reynolds number (Re) on the configuration of hydrothermal behavior as well as Nusselt number (Nu) and Darcy factor (f) have been investigated. Utilizing ferrofluid can enhance Nu, while the pressure drop augmentation is negligible. So, selecting such kind of ferrofluid is a promising way to gain better performance. Given Re = 50, Nu enhances by about 1.3% with an increase of the concentration of ferrofluid from 0.01 to 0.04. The rise of Re needs greater pumping power as a higher pressure drop will appear in this case. Besides, a thinner boundary layer has been formed with the growth of Re, which offers a higher Nu. When Mn* = 1.57, the growth of Re provides an augmentation of Nu by 39%. With augmenting Kelvin force, the velocity of ferrofluid enhances, which results in a higher pressure drop.
Numerical Investigation of Fuel Property Effects on Mixed-Mode Combustion in a Spark-Ignition Engine
Authors: Xu Chao , Pal Pinaki , Ren Xiao , Sjöberg Magnus , Van Dam Noah , Wu Yunchao , Lu Tianfeng , McNenly Matthew , Som Sibendu
Published: August 2020

In this study, lean mixed-mode combustion is numerically investigated using computational fluid dynamics (CFD) in a spark-ignition engine. A new E30 fuel surrogate is developed using a neural network model with matched octane numbers. A skeletal mechanism is also developed by automated mechanism reduction and by incorporating a NOx submechanism. A hybrid approach that couples the G-equation model and the well-stirred reactor model is employed for turbulent combustion modeling. The developed CFD model is shown to well predict pressure and apparent heat release rate (AHRR) traces compared with experiment. Two types of combustion cycles (deflagration-only and mixed-mode cycles) are observed. The mixed-mode cycles feature early flame propagation and subsequent end-gas auto-ignition, leading to two distinctive AHRR peaks. The validated CFD model is then employed to investigate the effects of NOx chemistry. The NOx chemistry is found to promote auto-ignition through the residual gas, while the deflagration phase remains largely unaffected. Sensitivity analysis is finally performed to understand effects of fuel properties, including heat of vaporization (HoV) and laminar flame speed (SL). An increased HoV tends to suppress auto-ignition through charge cooling, while the impact of HoV on flame propagation is insignificant. In contrast, an increased SL is found to significantly promote both flame propagation and end-gas auto-ignition. The promoting effect of SL on auto-ignition is not a direct chemical effect; it is rather caused by an advancement of the combustion phasing, which increases compression heating of the end-gas.
Assessment of Conventional and Alternative Energy Carriers for Use in Military Vehicle Platforms
Authors: Mansfield A. , Boehman A. , Gorsich D.
Published: August 2020

Interest in alternative energy carriers for military transportation applications prompted significant investigation, which revealed military-specific benefits and challenges of electric hybrid energy carrier systems. In the years since these studies, the types and performance of alternative energy carrier technologies have rapidly advanced. The objectives of this work were to survey and characterize commercial and near-term transportation energy carriers and then assess their use in several specific military vehicles. Comprehensive databases were constructed which quantify the energy density, specific energy, and power density of various energy carriers, storage systems, and energy conversion devices, through a survey of the scientific and industrial literature. These databases were then used in conjunction with basic operating requirements for the high-mobility multipurpose wheeled vehicle and family of medium tactical vehicles military vehicle platforms to approximate the total powertrain mass as well as the total volume of stored energy, for various energy carriers for each vehicle platform. Results indicate that the use of pure gasoline or diesel fuels in these vehicle platforms yields by far the lowest total powertrain mass and stored energy; thus, despite recent advancements in alternative energy carrier technologies, significant powertrain mass and stored volume penalties for their implementation remain. Li ion battery diesel hybrids were the most promising near-term application of alternative energy carrier, with the commercialization of Li ion battery technologies found to have significantly reduced mass and volume penalties. The databases and trends developed here inform the broader consideration of alternative energy carriers used in military vehicles.
Investigation on the Radial Heat-Transfer of Pumping Secondary Flow in Semiclosed Rotating Disk Cavity
Authors: Luo Guohu , Yao Zhenqiang
Published: August 2020

This study investigates the mean flow and radial heat-transfer behaviors in semiclosed rotating disk cavity within the canned reactor coolant pump. The flow in the semiclosed cavity contains the Stewartson type flow at inner region and the Batchelor type flow at outer region. The heat is radially transported from the outer rim of the semiclosed disk cavity to discharge-hole through the nondirect discharge (ND) portion of the superimposed flow from inlet. The effects of rotating Reynolds numbers, cavity aspect ratio and radial location of discharge-hole on the discharge ratio, pumping mass flow rate, local wall shear stress and radial heat-transfer coefficient are examined in the semiclosed rotating cavity flow, respectively. Based on the radial heat transfer behaviors of pumping secondary flow, an equivalent thermal network is proposed and validated by experiments, which can effectively predict the radial temperature distribution from the discharge hole to periphery with the viscous-heating and nonisothermal effects.
The UGKS Simulation of Microchannel Gas Flow and Heat Transfer Confined Between Isothermal and Nonisothermal Parallel Plates
Authors: Dai Lianfu , Wu Huiying , Tang Jun
Published: August 2020

The unified gas kinetic scheme (UGKS) is introduced to simulate the near transition regime gas flow and heat transfer in microchannel confined between isothermal and nonisothermal parallel plates. The argon gas is used and its inlet Knudsen number (Knin) ranges from 0.0154 to 0.0715. It is found that: (1) both microchannel gas flows under isothermal and nonisothermal parallel plates display a trend of speed acceleration and temperature decrease along flow direction, for which the microscopic mechanism explanation is first proposed; (2) inlet gas streamlines under nonisothermal plates condition deviate from the parallel distributions under isothermal plates condition due to the dual driving effects of pressure drop along flow direction and temperature difference along cross section; (3) gas temperature, pressure, density and viscosity distributions along cross section under nonisothermal plates condition deviate from the parabolic distributions under isothermal plates condition, while the gas velocity keeps the parabolic distribution due to the effect of Knudsen layer; (4) as channel height increases or channel length and gas molecular mean free path decrease, the gas temperature distribution along cross section under nonisothermal plates condition tends to transition from linear to curve one due to the decreasing effect of heat transfer along cross section and increasing effect of gas acceleration along flow direction, this transition from linear to curve one becomes more obvious along flow direction. (5) the gas velocity under nonisothermal plates condition decreases with the increase of inlet gas temperature (Tin), lower plate temperature (Tl) and Knin, while the gas temperature increases with the increase of Tin, Tl and Knin.
Classification of a 3-RER Parallel Manipulator Based on the Type and Number of Operation Modes
Authors: Kong Xianwen
Published: August 2020

The type/number of operation modes of a parallel manipulator (PM) may vary with the link parameters of the PM. This paper presents a systematic classification of a 3-RER PM based on the type/number of operation modes. Here, R and E denote revolute joint and planar joint, respectively. The 3-RER PM was proposed as a 4-degree-of-freedom (DOF) 3T1R PM in the literature. Using the proposed method, classification of a PM based on the type/number of operation modes can be carried out in four steps, including formulation of constraint equations of the PM, preliminary classification of the PM using Gröbner cover, operation mode analysis of all the types of PMs using primary decomposition of ideals, and identification of redundant types of PMs. The classification of the 3-RER PM shows that it has 13 types. Besides the two 4-DOF 3T1R operation modes, different types of 3-RER PMs may have up to two more 3-DOF or other types of 4-DOF operation modes. Motion characteristics of the moving platform of 3-RER PMs are also identified using Euler parameter quaternions. This work is the first systematic study on the impact of link parameters on the operation modes of the 3-RER PM and provides a solid foundation for further research on the design and control of 3-RER PMs and other multi-mode (or reconfigurable) PMs.
An Assessment of Homogeneous Mixture Method Cavitation Models in Predicting Cavitation in Nozzle Flow
Authors: Villafranco Dorien O. , Gupta Ankush , Ryan Emily M. , Holt R. Glynn , Grace Sheryl M.
Published: August 2020

The homogeneous mixture method (HMM) is a popular class of models used in the computational prediction of cavitation. Several cavitation models have been developed for use with HMM to govern the development and destruction of vapor in a fluid system. Two models credited to Kunz and Schnerr–Sauer are studied in this paper. The goal of this work is to provide an assessment of the two cavitation submodels in their ability to predict cavitation in nozzle flow. Validation data were obtained via experiments which employ both passive cavitation detection, (PCD) via acoustic sensing and optical cavitation detection (OCD) via camera imaging. The experiments provide quantitative information on cavitation inception and qualitative information on the vapor in the nozzle. The results show that initial vapor formation is not predicted precisely but within reason. A sensitivity analysis of the models to input parameters shows that the Schnerr–Sauer method does not depend upon the estimation of nuclei size and number density. Small changes in the vapor formation rate but not the total vapor volume can be seen when weighting parameters are modified. In contrast, changes to the input parameters for the Kunz model greatly change the final total vapor volume prediction. The assessment also highlights the influence of vapor convection within the method. Finally, the analysis shows that if the fluid and nozzle walls do not support nuclei larger than 40 μm, the methods would still predict cavitation when indeed there would be none in practice.
A Water Droplet Impact on a Hydrophobic Soft Surface
Authors: Abubakar Abba Abdulhamid , Yilbas Bekir Sami , Al-Qahtani Hussain
Published: August 2020

Impacting water droplet on a hydrophobic soft surface is investigated and impacting droplet behavior during the spreading and retraction phases is examined. Polyisoprene elastomer surface is hydrophobized via deposition with functionalized nanosilica particles using the dip coating method. Hydrophobized surface results in the contact angle of 135 ± 3 deg with a hysteresis of 2 ± 1 deg, and stretching and stretch relaxing of the coated samples do not alter the wetting state of the surfaces. Pressure variation, spreading, and retraction rates of droplet are simulated and findings are validated through the experimental data obtained from high-speed video system. The findings are also compared to those obtained for the impacting droplet on the hydrophobized glass surfaces. It is observed that predictions of droplet height and droplet shape agree well with the experimental data. Spreading period of the impacting droplet on the hydrophobized elastomer surface is longer than the hydrophobic glass surface; contrary, the retraction period of the impacting droplet is shorter on the elastomer surface than the glass surface. Impacting droplet generates large amplitude oscillatory surface waves on the elastomer surface and as the time progresses the wave amplitude reduces considerably, particularly along the surface (x-axis).
Early stage of marine biofilm formation on duplex stainless steel
Authors: Gardin Elise , Zanna Sandrine , Seyeux Antoine , Mercier Dimitri , Allion-Maurer Audrey , Marcus Philippe
Published: August 2020

The aim of this work was to investigate the bacteria-surface interactions occurring during the first hour of adhesion of marine Pseudoalteromonas NCIMB 2021 at the surface of 2304 lean duplex stainless steel in artificial seawater. A complete characterization of the biofilm and the passive film was performed coupling epifluorescence microscopy, scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and time of flight secondary ion mass spectrometry (ToF-SIMS). The coupling of XPS and ToF-SIMS analyses revealed that (1) protein and polysaccharide contents in the biofilm are similar in the presence or absence of nutrients, (2) the biofilm is mainly composed of proteins and the protein content is similar to the one of Tightly Bound EPS, (3) increased bacterial activity due to nutrients leads to chromium enrichment in the passive film in close vicinity to the bacteria.
The Role of Quiet Eye Duration and Its Components in a Complex Far-Aiming Task
Authors: Moeinirad Samira , Abdoli Behrouz , Farsi Alireza , Ahmadi Nasour
Published: August 2020

The quiet eye is a characteristic of highly skilled perceptual and motor performance that is considered as the final fixation toward a target before movement initiation. The aim of this study was to extend quiet eye–related knowledge by investigating expertise effects on overall quiet eye duration among expert and near-expert basketball players, as well as to determine the relative contribution of early and late visual information in a basketball jump shot by comparing the timing components of quiet eye duration (early and late quite eye). Twenty-seven expert and near-expert male basketball players performed the jump shots. Gaze was recorded with the SensoMotoric Instruments eye tracking glasses and shooting performance accuracy was evaluated by scoring each shot on a scale of 1–8. Six infrared cameras circularly arranged around the participants were used to collect the kinematic information of the players. The performance accuracy, gaze behavior, and kinematic characteristics of the participants during the test were calculated. The experts with longer quiet eye duration had better performance in a basketball jump shot compared to the near-experts. Also the experts had longer early and late quiet eye duration than the near-experts. The results revealed a relationship between quiet eye duration and performance. The combined visual strategy is a more efficient strategy in complex far-aiming tasks such as a basketball jump shot.
Physical Activity Among Immigrant Children: A Systematic Review
Authors: Lacoste Yannick , Dancause Kelsey Needham , Gosselin-Gagne Justine , Gadais Tegwen
Published: August 2020

Background: The health benefits of physical activity (PA) for children are well documented. However, little is known about PA patterns among immigrant children. Methods: The authors reviewed research on PA patterns of immigrant children. The inclusion criteria included peer-reviewed articles published from January 2010 to May 2018 in English, French, or Spanish that included primary-school-aged (6–12 y) children, and data on immigration status. Results: A total of 11 articles were included in the analyses. These studies revealed a deficit of PA among immigrant children. Immigration status (immigrant or nonimmigrant) and generation of immigration (first, second, and third), ethnic origin, and gender were associated with PA patterns. In general, PA levels were lower among first-generation immigrant children, children of Hispanic and East Asian origin, and girls. The results suggest that questionnaire measures might be biased or inaccurate among immigrant children, highlighting the need for the integration of mixed methods (objective and subjective measures). Conclusions: A large proportion of children do not meet PA guidelines, and this might be more problematic for immigrant children. Future studies incorporating time since immigration, comparative analyses on gender, sociocultural and socioeconomic characteristics, and mixed methodology could provide a more complete portrait of PA patterns and opportunities for immigrant children.
Pharmacodynamic Evaluation of MRX-8, a Novel Polymyxin, in the Neutropenic Mouse Thigh and Lung Infection Models against Gram-Negative Pathogens
Authors: Lepak Alexander J. , Wang Wen , Andes David R.
Published: August 2020

MRX-8 is a novel polymyxin analogue in development for the treatment of infections caused by Gram-negative pathogens, including those resistant to other antibiotic classes. In the present study, we examined the pharmacodynamic activity of MRX-8 against a variety of common Gram-negative pathogens in the neutropenic mouse thigh and lung models. Additionally, we examined polymyxin B (PMB) as a comparator. Plasma pharmacokinetics of MRX-8 and PMB were linear over a broad dosing range of 0.156 to 10 mg/kg of body weight and had similar AUC
0–∞
(area under the drug concentration-time curve from 0 h to infinity) exposures of MRX-8, 0.
Structural Characterization of the Essential Cell Division Protein FtsE and Its Interaction with FtsX in Streptococcus pneumoniae
Authors: Alcorlo Martin , Straume Daniel , Lutkenhaus Joe , Håvarstein Leiv Sigve , Hermoso Juan A.
Published: August 2020

Bacterial cell division is a central process that requires exquisite orchestration of both the cell wall biosynthetic and lytic machineries. The essential membrane complex FtsEX, widely conserved across bacteria, plays a central role by recruiting proteins to the divisome apparatus and by regulating periplasmic muralytic activity from the cytosol. FtsEX is a member of the type VII family of the ABC-superfamily, but instead of being a transporter, it couples the ATP hydrolysis catalyzed by FtsE to mechanically transduce a conformational signal that provokes the activation of peptidoglycan (PG) hydrolases. So far, no structural information is available for FtsE. Here, we provide the structural characterization of FtsE, confirming its ATPase nature and revealing regions with high structural plasticity which are key for FtsE binding to FtsX. The complementary binding region in FtsX has also been identified and validated
in vivo
. Our results provide evidence on how the difference between the ATP/ADP-bound states in FtsE would dramatically alter the interaction of FtsEX with the PG hydrolase PcsB in pneumococcal division.
HbtR, a Heterofunctional Homolog of the Virulence Regulator TcpP, Facilitates the Transition between Symbiotic and Planktonic Lifestyles in Vibrio fischeri
Authors: Bennett Brittany D. , Essock-Burns Tara , Ruby Edward G.
Published: August 2020

TcpP homologs are widespread throughout the
Vibrio
genus; however, the only protein in this family described thus far is a
V. cholerae
virulence regulator. Here, we show that HbtR, the TcpP homolog in
V. fischeri
, has both a biological role and regulatory pathway completely unlike those in
V. cholerae
. Through its repression of the quorum-signaling regulator LitR, HbtR affects the expression of genes important for colonization of the
E. scolopes
light organ. While LitR becomes activated within the crypts and upregulates luminescence and exopolysaccharide genes and downregulates chemotaxis and motility genes, it appears that HbtR, upon expulsion of
V. fischeri
cells into seawater, reverses this process to aid the switch from a symbiotic to a planktonic state. The possible importance of HbtR to the survival of
V. fischeri
outside its animal host may have broader implications for the ways in which bacteria transition between often vastly different environmental niches.
Molecular Deceleration Regulates Toxicant Release to Prevent Cell Damage in Pseudomonas putida S16 (DSM 28022)
Authors: Tang Hongzhi , Zhang Kunzhi , Hu Haiyang , Wu Geng , Wang Weiwei , Zhu Xiongyu , Liu Gongquan , Xu Ping
Published: August 2020

Flavin-dependent amine oxidases have received extensive attention because of their importance in drug metabolism, Parkinson’s disease, and neurotransmitter catabolism. However, the underlying molecular mechanisms remain relatively poorly understood. Here, combining the crystal structure of NicA2 (an enzyme in the first step of the bacterial nicotine degradation pathway in
Pseudomonas putida
S16 (DSM 28022)), biochemical analysis, and mutant construction, we found an intriguing exit passage in which bulky amino acid residues occlude the release of the toxic product of NicA2, in contrast to other, related structures. The selective product exportation register for NicA2 has proven to be beneficial to cell growth. Those seeking to produce cytotoxic compounds could greatly benefit from the use of such an export register mechanism.
Metabolic Feedback Inhibition Influences Metabolite Secretion by the Human Gut Symbiont Bacteroides thetaiotaomicron
Authors: Catlett Jennie L. , Catazaro Jonathan , Cashman Mikaela , Carr Sean , Powers Robert , Cohen Myra B. , Buan Nicole R.
Published: August 2020

Bacteroides
is a highly abundant taxon in the human gut, and
Bacteroides thetaiotaomicron
(
B. theta
) is a ubiquitous human symbiont that colonizes the host early in development and persists throughout its life span. The phenotypic plasticity of keystone organisms such as
B. theta
is important to understand in order to predict phenotype(s) and metabolic interactions under changing nutrient conditions such as those that occur in complex gut communities. Our study shows
B. theta
prioritizes energy conservation and suppresses secretion of “overflow metabolites” such as organic acids and amino acids when concentrations of acetate are high. Secreted metabolites, especially amino acids, can be a source of nutrients or signals for the host or other microbes in the community. Our study suggests that when metabolically stressed by acetate,
B. theta
stops sharing with its ecological partners.
Young people’s views on their role in the COVID-19 pandemic and society’s recovery from it
Authors: Larcher Vic , Dittborn Mariana , Linthicum James , Sutton Amy , Brierley Joe , Payne Christopher , Hardy Hannah
Published: August 2020

Objective

There has been little formal exploration of how young people see their role in the COVID-19 pandemic.

Design/setting

Focus-group discussion with 15 Children’s Hospital Young People’s Forum members (23/5) to explore their perspective on the impact of COVID-19 on both their lives and those of their community, on school closures, and the role they wished to play in society’s recovery from the pandemic. Audio recordings were transcribed verbatim using NVivo Software and analysed using an inductive thematic analysis approach.

Outcome

Four major themes identified: (1) Awareness of pandemic’s impact on others: participants showed mature awareness of the effects on broader society, especially the elderly, socially disadvantaged and parents. (2) Perceived impact on their own lives: principal concerns were the educational and practical repercussions of school closures and social isolation, including effects on educational prospects. (3) Views about school reopening: young people understood the broader rationale for school reopening and were generally positive about it, but expressed concerned about their safety and that of others. (4) Communication issues: a need for clear, concise, understandable information readily accessible for young people was expressed. Up to now, they felt passive recipients rather than participants.

Conclusion

Young people were concerned about their future, their family and broader society, consistent with a high level of moral development. They want to be active participants in social recovery, including concepts around return to school but require appropriate information and a means by which their voices can be heard. The alternative suggested roles as pawns or pathfinders were discounted.
Bilateral idiopathic granulomatous mastitis
Authors: Gupta Nikhil , Vats Manu , Garg Mradul , Dahiya Davinder Singh
Published: August 2020

A 35-year-old woman presented to the surgery outpatient department with a lump in her right breast for 2 months and pain for 1 month. After clinical examination and relevant investigations, we kept a working diagnosis of antibioma. The lump was excised under local anaesthesia and biopsy was sent. However, histopathological examination reported multiple non-caseating granulomas without acid-fast bacilli. Two months later, she developed a sinus with serous discharge at the scar site. At the same time, she developed pain in the left upper breast, which subsequently progressed to an abscess. Incision and drainage of the abscess was done, but the wound did not heal, and a discharging sinus appeared at the site. Finally, a diagnosis of idiopathic granulomatous mastitis was made, after excluding all other causes, and the patient was prescribed oral steroids. She recovered fully after 8 months and there is no recurrence till date.
Practical metrics for establishing the health benefits of research to support research prioritisation
Authors: Woods Beth , Schmitt Laetitia , Rothery Claire , Phillips Andrew , Hallett Timothy B , Revill Paul , Claxton Karl
Published: August 2020

Introduction

We present practical metrics for estimating the expected health benefits of specific research proposals. These can be used by research funders, researchers and healthcare decision-makers within low-income and middle-income countries to support evidence-based research prioritisation.

Methods

The methods require three key assessments: (1) the current level of uncertainty around the endpoints the proposed study will measure; (2) how uncertainty impacts on the health benefits and costs of healthcare programmes and (3) the health opportunity costs imposed by programme costs. Research is valuable because it can improve health by informing the choice of which programmes should be implemented. We provide a Microsoft Excel tool to allow readers to generate estimates of the health benefits of research studies based on these three assessments. The tool can be populated using existing studies, existing cost-effectiveness models and expert opinion. Where such evidence is not available, the tool can quantify the value of research under different assumptions. Estimates of the health benefits of research can be considered alongside research costs, and the consequences of delaying implementation until research reports, to determine whether research is worthwhile. We illustrate the method using a case study of research on HIV self-testing programmes in Malawi. This analysis combines data from the literature with outputs from the HIV synthesis model.

Results

For this case study, we found a costing study that could be completed and inform decision making within 1 year offered the highest health benefits (67 000 disability-adjusted life years (DALYs) averted). Research on outcomes improved population health to a lesser extent (12 000 DALYs averted) and only if carried out alongside programme implementation.

Conclusion

Our work provides a method for estimating the health benefits of research in a practical and timely fashion. This can be used to support accountable use of research funds.
The health of internally displaced children in sub-Saharan Africa: a scoping review
Authors: Salami Bukola , Iwuagwu Stella , Amodu Oluwakemi , Tulli Mia , Ndikom Chizoma , Gommaa Hayat , Lavin Tina , Kariwo Michael
Published: August 2020

Background

Internally displaced children are those who have been forced to flee their homes due to severe unfavourable conditions (war, violence or disasters) but have not crossed international borders. Emerging research shows these children face multiple health challenges. However, we found no review focused solely on the health of such internally displaced children. Thus, this review sought to examine what is known about their health and their health concerns.

Methods

A scoping review of the literature was conducted. A total of 10 databases were searched in January 2019, yielding 6602 articles after duplicates were eliminated. Two research assistants independently selected articles that met inclusion criteria. A numerical summary and thematic analysis were conducted to facilitate data extraction and data analysis.

Results

A total of 25 articles met the inclusion criteria, including 16 quantitative, 6 qualitative and 3 mixed methods studies. The findings reveal elevated mental health problems and infectious diseases in this population. Findings on the nutritional status of internally displaced children as a broad group are mixed, with some studies showing poorer nutritional status among the children in this group and others showing poorer nutritional health status among host society children. Internally displaced children also experience challenges with access to health services. Premigration factors (trauma) and postmigration factors (humanitarian assistance on displacement) all contribute to the health of internally displaced children.

Conclusion

Findings provide insight into the complex array of factors influencing the health of internally displaced children. More intervention studies are required to address the needs of this population.
Cost-effectiveness of neonatal surgery for congenital anomalies in low-income and middle-income countries: a systematic review protocol
Authors: Kim Na Eun , Vervoot Dominique , Hammouri Ahmad , Riboni Cristiana , Salem Hosni , Grimes Caris , Wright Naomi Jane
Published: August 2020

Introduction

Congenital anomalies are the fifth leading cause of death in children under 5 years old globally (591 000 deaths reported in 2016). Over 95% of deaths occur in low-income and middle-income countries (LMICs). It is estimated that two-thirds of the congenital anomaly health burden could be averted through surgical intervention and that such interventions can be cost-effective. This systematic review aims to evaluate current evidence regarding the cost-effectiveness of neonatal surgery for congenital anomalies in LMICs.

Methods and analysis

A systematic literature review will be conducted in PubMed, MEDLINE, Embase, Cochrane Library, Scielo, Google Scholar, African Journals OnLine and Regional WHO’s African Index Medicus databases for articles on the cost-effectiveness of neonatal surgery for congenital anomalies in LMICs. The following search strings will be used: (1) congenital anomalies; (2) LMICs; and (3) cost-effectiveness of surgical interventions. Articles will be uploaded to Covidence software, duplicates removed and the remaining articles screened by two independent reviewers. Cost information for interventions or procedures will be extracted by country and condition. Outcome measurements by reported unit and cost-effectiveness ratios will be extracted. Methodological quality of each article will be assessed using the Drummond checklist for economic evaluations. The Agency for Healthcare Research and Quality’s Effective Health Care Program guidance will be followed to assess the grade of the studies.

Ethics and dissemination

No ethical approval is required for conducting the systematic review. There will be no direct collection of data from individuals. The finalised article will be published in a scientific journal for dissemination. The protocol has been registered with PROSPERO (International Prospective Register of Systematic Reviews).

Conclusion

Congenital anomalies form a large component of the global health burden that is amenable to surgical intervention. This study will systematically review the current literature on the cost-effectiveness of neonatal surgery for congenital anomalies in LMICs.

PROSPERO registration number

CRD42020172971.
Age pattern of sexual activities with the most recent partner among men who have sex with men in Melbourne, Australia: a cross-sectional study
Authors: Kilner Alex , Fairley Christopher K , Burrell Sam , Bradshaw Catriona S , Chen Marcus Y , Chow Eric P F
Published: August 2020

Background

Sexual behavioural studies among men who have sex with men (MSM) are predominantly focused on penile-anal intercourse. Other non-anal sexual activities are under-studied. This study aimed to examine the age pattern of a range of sexual activities among MSM with the most recent male sex partner.

Methods

We conducted a survey among MSM attending the Melbourne Sexual Health Centre in 2017. This survey asked about nine different sexual activities with their most recent regular and casual partner. A Chi-square trend test was used to examine the age patterns of each sexual activity.

Results

A total of 1596 men answered the survey and their median age was 30 (IQR 25–37) years. With casual partners, kissing was the most common activity (92.4%), followed by performing penile-oral sex (86.0%) and receiving penile-oral sex (83.9%). The least common activity was insertive rimming (38.1%). Young men were more likely to engage in kissing (ptrend<0.001), receptive rimming (ptrend=0.004) and receptive penile-anal sex (ptrend<0.001) but they were less likely to have insertive penile-anal sex compared with older MSM. With regular partners, the most common activity was kissing (97.4%), followed by touching penises (90.0%) and performing penile-oral sex (88.3%). Age was not associated with most types of sexual activity with regular partners except mutual masturbation and receptive penile-anal sex. Younger men were more likely to masturbate mutually (ptrend=0.028) and engage in receptive penile-anal sex (ptrend=0.011).

Conclusions

The pattern of sexual activities shows age-related differences with casual partners but less so with regular partners in MSM.
A psychological health support scheme for medical teams in COVID-19 outbreak and its effectiveness
Authors: Cheng Wenhong , Zhang Fang , Liu Zhen , Zhang Hao , Lyu Yifan , Xu Hao , Hua Yingqi , Gu Jiarong , Yang Zhi , Liu Jun
Published: August 2020

Background

Medical staff fighting the COVID-19 pandemic are experiencing stress from high occupational risk, panic in the community and the extreme workload. Maintaining the psychological health of a medical team is essential for efficient functioning, but psychological intervention models for emergency medical teams are rare.

Aims

To design a systematic, full-coverage psychological health support scheme for medical teams serving large-scale emergent situations, and demonstrate its effectiveness in a real-world study in Leishenshan Hospital during the COVID-19 epidemic in Wuhan, China.

Methods

The scheme integrates onsite and online mental health resources and features team-based psychosocial support and evidence-based interventions. It contained five modules, including a daily measurement of mood, a daily mood broadcast that promotes positive affirmation, a daily online peer-group activity with themes based on the challenges reported by the team, Balint groups and an after-work support team. The daily mood measurement provides information to the other modules. The scheme also respects the special psychological characteristics of medical staff by promoting their strengths.

Results

The scheme economically supported a special medical team of 156 members with only one onsite psychiatrist. Our data reflected that the entire medical team maintained an overall positive outlook (7–9 out of 10 in a Daily Mood Index, DMI) for nearly 6 weeks of continuous working. Since the scheme promoted self-strengths and positive self-affirmation, the number of self-reports of life-related gains were high and played a significant effect on the DMI. Our follow-up investigations also revealed that multiple modules of the scheme received high attention and evaluation levels.

Conclusion

Our quantitative data from Leishenshan hospital, Wuhan, China, show that the programme is adequate to support the continuous high workload of medical teams. This scheme could be applied to medical teams dealing with emergent situations.
Clinical practice guidelines adherence, knowledge and awareness in rare and complex connective tissue diseases across Europe: results from the first ERN ReCONNET survey
Authors: Talarico Rosaria , Marinello Diana , Bombardieri Stefano , Burmester Gerd , Fonseca Joao , Frank Charissa , Galetti Ilaria , Hachulla Eric , Houssiau Frederic , Mueller-Ladner Ulf , Schneider Matthias , Smith Vanessa , Turchetti Giuseppe , van Laar Jacob M , Vieira Ana , Cutolo Maurizio , Mosca Marta
Published: August 2020

Introduction

The European Reference Network (ERN) ReCONNET is the ERN aimed at improving the management of rare and complex connective tissue and musculoskeletal diseases (rCTDs) across the European Union (EU). In the mission of ERN ReCONNET, clinical practice guidelines (CPGs) play a crucial role, representing a valid tool towards the harmonisation of the management of rCTDs while improving effectiveness and quality of care delivered to patients.

Methods

ERN ReCONNET developed two surveys to map the adherence to rCTDs CPGs among healthcare providers and to assess the knowledge and awareness of CPGs for their diseases among patients, family members and caregivers.

Results

The results of the surveys highlighted that healthcare professionals find it useful to apply CPGs in clinical practice (93%), while 62% of them experience difficulties and barriers in the application in their centres. Healthcare professionals also highlighted the need to develop CPGs for all rCTDs and to implement the use of the existing CPGs in clinical practice. On the other hand, patients, families and caregivers are relatively aware of the purpose of CPGs (51%) and 62% of them were aware of the existence of CPGs for their disease. Patient-friendly versions of CPGs and patients’ lifestyle guidelines should be systematically developed contributing to the empowerment of patients in the disease management.

Conclusion

ERN ReCONNET is addressing the main issues identified in the results of the survey, promoting practical actions for the local adaptation of CPGs across Europe, improving their routine clinical use and increasing the awareness on CPGs among rCTDs patients, family members and caregivers.
PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE)—a population-based prospective cohort study: rationale, design and baseline participant characteristics
Authors: Pan Yuesong , Jing Jing , Cai Xueli , Wang Yilong , Wang Suying , Meng Xia , Zeng Chunlai , Shi Jiong , Ji Jiansong , Lin Jinxi , Lyu Lingchun , Zhang Zhe , Mei Lerong , Li Shiping , Li Shan , Zhu Wanlin , Li Hao , Wei Tiemin , Wang Yongjun
Published: August 2020

Background and purpose

Cardiovascular diseases and dementia are two major diseases in the elderly. Atherosclerosis is associated with future vascular events and cognitive impairment. The PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE) study is a population-based prospective cohort study with comprehensive evaluation of multiterritorial artery stenosis and plaque using advanced vascular imaging techniques and prospective collection of vascular events and cognitive assessments.

Methods

Between May 2017 and September 2019, the PRECISE study enrolled 3067 community-dwelling adults with ages between 50 and 75 years cluster sampled from six villages and four communities of Lishui city in China. Data are collected in face-to-face interviews at baseline, 2-year and 4-year follow-up visits. Brain MRI including high-resolution sequences for intracranial and carotidal arteries and CT angiography for thoracoabdominal arteries were performed at baseline and will be rescanned after 4 years. Cardiovascular/cerebrovascular events and cognitive assessment will be prospectively collected after the enrollment. Blood and urine samples were collected and biomarkers were tested at baseline.

Results

A total of 3067 subjects were enrolled, among which 53.5% were female with an average age of 61.2±6.7 years. Among them, 2.8%, 8.1%, 43.1% and 21.6% had a history of stroke, heart diseases, hypertension and diabetes mellitus, respectively.

Conclusions

The PRECISE study is a population-based prospective cohort study with comprehensive evaluation of atherosclerotic stenosis and plaque using advanced vascular imaging techniques. Data from this cohort provide us an opportunity to precisely evaluate polyvascular atherosclerosis and its association with future vascular events and cognitive impairment.

Trial registration number

ClinicalTrials.gov Registry (NCT03178448).
Intrahepatic icterus in pigs: rare clinical sign in porcine circovirus type 2 systemic disease
Authors: Graage Robert , Saura Martinez Helena , Klausmann Stefanie , Kubacki Jakub , Kümmerlen Dolf
Published: August 2020

Icterus is a yellow discolouration of tissue and blood plasma due to a disorder of the bilirubin metabolism. This case report describes two porcine circovirus type 2 (PCV2) outbreaks in a fattening farm (F1) and a breeding farm (F2). At F1, pigs had intradermal bleedings and wasting, and three pigs showed icterus. At F2, suckling and weaning pigs (WPs) had an icterus and were wasted. Three fattening pigs (F1), one suckling piglet and one WP (F2) were dissected. Additional investigations included histology, PCV2 immunohistochemistry (IHC), fluorescence in situ hybridisation (FISH) of tissue samples, PCR including sequencing of the PCV2 strains and next‐generation sequencing (NGS) of liver samples. Three of the five dissected pigs showed a lymphohistiocytic, periportal hepatitis with disruption of the hepatic cord architecture. PCV2 was detected by IHC, FISH, PCR and NGS in several organs of the pigs. In both farms, sequencing revealed a PCV2b genotype.
Homologous chromosome pairing in meiosis of higher eukaryotes—still an enigma?
Authors: Sybenga J.
Published: August 2020

Meiosis is the basis of the generative reproduction of eukaryotes. The crucial first step is homologous chromosome pairing. In higher eukaryotes, micrometer-scale chromosomes, micrometer distances apart, are brought together by nanometer DNA sequences, at least a factor of 1000 size difference. Models of homology search, homologue movement, and pairing at the DNA level in higher eukaryotes are primarily based on studies with yeast where the emphasis is on the induction and repair of DNA double-strand breaks (DSB). For such a model, the very large nuclei of most plants and animals present serious problems. Homology search without DSBs cannot be explained by models based on DSB repair. The movement of homologues to meet each other and make contact at the molecular level is not understood. These problems are discussed and the conclusion is that at present practically nothing is known of meiotic homologue pairing in higher eukaryotes up to the formation of the synaptonemal complex, and that new, necessarily speculative models must be developed. Arguments are given that RNA plays a central role in homology search and a tentative model involving RNA in homology search is presented. A role of actin in homologue movement is proposed. The primary role of DSBs in higher eukaryotes is concluded to not be in pairing but in the preparation of Holliday junctions, ultimately leading to chromatid exchange.
Scotogenic neutrino mass with large $$SU(2)_L$$ multiplet fields
Authors: Kumar Nilanjana , Nomura Takaaki , Okada Hiroshi
Published: August 2020

We construct a scotogenic neutrino mass model introducing large $$SU(2)_L$$SU(2)L multiplet fields without adding an extra symmetry. We have introduced extra scalar fields such as a septet, quintet and quartet where we make the vacuum expectation value of quartet scalar to be zero while septet and quintet develop non-zero ones. Then the neutrino mass is generated at one-loop level by introducing quintet fermion. We analyze the neutrino mass matrix taking constraints from lepton flavor violation into account and discuss collider physics regarding charged fermions from large multiplet fields. We have analysed the production and the decays of the quintet fermions, as well as the discovery reach at 14 TeV and 27 TeV LHC.
Even–odd conductance effect in graphene nanoribbons induced by edge functionalization with aromatic molecules: basis for novel chemosensors
Authors: Čerņevičs Kristiāns , Pizzochero Michele , Yazyev Oleg V.
Published: August 2020

We theoretically investigate the electron transport in armchair and zigzag graphene nanoribbons (GNRs) chemically functionalized with p-polyphenyl and polyacene groups of increasing length. Our nearest-neighbor tight-binding calculations indicate that, depending on whether the number of aromatic rings in the functional group is even or odd, the resulting conductance at energies matching the energy levels of the corresponding isolated molecule is either unaffected or reduced by exactly one quantum as compared to the pristine GNR, respectively. Such an even–odd effect is shown to originate from a subtle interplay between the electronic states of the guest molecule that are spatially localized on the binding sites and those of the host nanoribbon. We next generalize our findings by employing more accurate tight-binding Hamiltonians along with density-functional theory calculations and critically discuss the robustness of the observed physical effects against the level of theory adopted. Our work offers a comprehensive understanding of the influence of aromatic molecules bound to the edge of graphene nanoribbons on their electronic transport properties, an issue which is instrumental to the prospective realization of graphene-based chemosensors.