bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study of Refrigerant (R134a) Condensate Retention on Paraffin Coated Plates and Fin Structures
Authors: Jin Hong-Qing , Ni Wentao , Wang Xiaofei
Published: December 2019

The refrigerant retained on heat transfer surfaces has a deleterious impact on the performance of heating, ventilation, air conditioning and refrigeration systems, which not only increases the thermal resistance between the vapor and surface, but also requires a higher charge to the system. In this work, a new paraffin coating has been applied on condensation surfaces, and R134a condensate retention has been studied on both copper plate and fins with (without) coating. The heat transfer coefficient was measured based on the one-dimensional heat conduction method and the retention was quantified using image processing. The results show that the heat transfer has been enhanced on the coated surfaces under a wide range of subcool degree, with a maximum increase of 27.4% in heat transfer coefficient; a reduced liquid retention has also been observed on paraffin coated fins with the retention area ratio decreased by 35.1% to 47.1% (depending on different subcool) compared to the uncoated fins. This work shows great potentials for reducing retained liquid and enhance heat transfer during refrigerant condensation.
Multi-Source Thermal Model for Electrical Harness Design
Authors: Petitgirard Julien , Baucour Philippe , Chamagne Didier , Fouillien Eric
Published: December 2019

The challenges of improving wiring harness design are safety, ecology, weight and cost. To achieve this, a better prediction of the temperature in the wiring harnesses is necessary. In terms, this involves considering a lot of compact thermal sources with an uncontrolled layout. Up to now, the main methods dedicated to resolution are based on finite elements given that temperature’s evolution according to several thermal sources, Joule effect, without controlled wire layout is complicated to evaluate.

This paper deals with an alternative and faster method. An analytic equation : Infinite Line Source (ILS), is used to create a nodal network. This method coming from geothermal heat exchangers relies on a fully-connected node network which is called here full-graph method. It will be shown that, for compact heat sources, this method can be improved with a reduced model. A reduced model is a pruned node network: only the wires corresponding to the adjoining wires are selected.

The bundle is a complex system which has a variable environment and an uncontrolled wire layout. The adaptation required by the models requires many assumptions. This case study focuses on a 10 wire configuration with the following assumptions: stationary state, identical wires, axial heat fluxes and neglected heat convection.

Comparative studies between the two nodal methods and a Finite Volumes Method (FVM) are also presented and discussed. From a physical point of view, the results are more interesting. Further investigations, depending on the different parameters, should lead us to make more realistic nodal methods.
Transient Determination on the Bulk Thermal Conductivity of Sub-Millimeter Thin Films of Composite Phase Change Thermal Interfacial Materials
Authors: Zhang Yu-Hong , Feng Biao , Tu Jing , Fan Li-Wu
Published: December 2019

The bulk thermal conductivity of thin films having a sub-millimeter thickness, made of composite phase change materials (PCM) and utilized as an emerging thermal interfacial material (TIM) for thermal management of electronics, was determined using the transient plane source (TPS) technique. The actual bulk thermal conductivity of the thin film samples was obtained by deconvoluting the thermal contact resistance (TCR) during the measurement process, according to the linear relationship between the nominal bulk thermal resistance and the thickness. The slope of the correlation curve is the reciprocal of film sample thermal conductivity and the intercept is the overall TCR. For the PCM35 thin film samples (which melt at around 35 °C) having three nominal thicknesses of 271±1 μm, 460±2 μm and 511±2 μm, the corrected results in the solid and liquid state were found to be approximately 0.487 W/m·K and 0.186 W/m·K, respectively. It was shown that the corrected values are greater than the direct readings from the TPS instrument as the latter involves the effect of TCR across multiple interfaces. The results obtained in this work could serve as reference property data for design of thermal management systems involving such phase change TIM.
Experimental Investigation of Crossflow Diverters in Jet Impingement Cooling
Authors: Madhavan Srivatsan , Ramakrishnan Kishore Ranganath , Singh Prashant , Ekkad Srinath V.
Published: December 2019

Jet impingement is a cooling technique commonly employed in combustor liner cooling and high-pressure gas turbine blades. However, jets from upstream impingement holes reduce the effectiveness of downstream jets due to jet deflection in the direction of crossflow. In order to avoid this phenomenon and provide an enhanced cooling on the target surface, we have attempted to come up with a novel design called “crossflow diverters”. Crossflow diverters are U-shaped ribs that are placed between jets in the crossflow direction (under maximum crossflow condition). In this study, the baseline case is jet impingement onto a smooth surface with 10 rows of jet impingement holes, jet-to-jet spacing of X/D = Y/D = 6 and jet-to-target spacing of Z/D = 2. Crossflow diverters with thickness ‘t’ of 1.5875 mm, height ‘h’ of 2D placed in the streamwise direction at a distance of X = 2D from center of the jet have been investigated experimentally. Transient liquid crystal thermography technique has been used to obtain detailed measurement of heat transfer coefficient for four jet diameter based Reynolds numbers of 3500, 5000, 7500, 12000. It has been observed that crossflow diverters protect the downstream jets from upstream jet deflection thereby maximizing their stagnation cooling potential. An average of 15–30% enhancement in Nusselt number is obtained over the flow range tested. However, this comes at the expense of increase in pumping power. Pressure drop for the enhanced geometry is 1–1.5 times the pressure drop for baseline impingement case. At a constant pumping power, crossflow diverters produce 9–15% enhancement in heat transfer coefficient as compared to baseline smooth case.
Monte Carlo Ray Tracing Coupled CFD Modelling and Experimental Testing of a 1 kW Solar Cavity Receiver Radiated via 7 kW HFSS
Authors: Ophoff Cedric , Ozalp Nesrin , Moens David
Published: December 2019

Current state-of-the-art development of concentrated solar power (CSP) applications target cost-effective and highly efficient processes in order to establish commercialization of these technologies. The design of solar receivers/reactors and their respective flow configuration have a direct impact on the operational performance of the solar thermochemical processes. Thermal efficiencies, reaction kinetics and other key output metrics are the intrinsic result of the chosen configuration. Therefore, reactor design optimization plays a crucial role in the development of solar thermochemical applications. In this study a computational fluid dynamics (CFD) model of a directly-irradiated cavity receiver has been developed. The CFD-domain is coupled with incoming radiation that is obtained by using Monte Carlo Ray Tracing (MCRT). Experimental campaigns of the cavity receiver were carried out using a 7 kW High Flux Solar Simulator (HFSS) as radiative source. Temperature readings were obtained at different locations inside the cavity receiver for both wall and gas temperatures. In order to mimic naturally changing insolation conditions, the HFSS was run at different power levels. Heat flux at the aperture of the solar receiver was experimentally characterized. The acquired heat flux maps validated the intermediate results obtained with the MCRT method. The coupled computational model was validated against the measured temperatures at different locations inside the receiver. Computed temperature contours inside the receiver confirmed the experimentally observed non-uniformity of the axial temperature distribution. The validated analysis presented in this paper was then used as a baseline case for a parametric study. Design optimization efforts were undertaken towards obtaining temperature uniformity and achieving efficient heat transfer within the fluid domain. Enhanced flow circulation was achieved which yielded temperature uniformity of the receiver at steady state conditions. The outcome of this parametric analysis provided valuable insights in the development of thermal efficient solar cavity receivers. Hence, findings of this study will serve as a starting point for future solar reactor design. For example, it was found that reversing flow direction has an adverse effect on the temperature uniformity inside the receiver. Similarly, increasing the inlet angle does not positively affect the temperature distribution and hence should be chosen carefully when designing a solar reactor.
Separating Wickability and Wetting Effects During Water Droplet Evaporation on Superhydrophilic Nanoporous Surfaces
Authors: Cooney Alanna Y. , McClure Emma R. , Cabrera Samuel , Carey Van P.
Published: December 2019

The dynamic behavior of impinging water droplets is studied in the context of varying surface wettability and wickability on smooth and nanostructured superhydrophilic surfaces. This study distinguishes the separate effects of wetting (contact angle), wickability, and inertia on the spreading and vaporization of water droplets deposited on nanoporous surfaces by considering experimental results in tandem with axisymmetric, volume of fluid (VOF) simulations of droplet spreading. High speed videos were obtained for water droplets spreading on nanoporous surfaces which exhibit very low (< 15°) contact angle and high wickability. In this study, the effect of wickability was assessed by comparing the experimental results, which include the low contact angle and high wickability effects, to predictions of the VOF model, which include only the ultralow contact angle. While a droplet touched to the nanostructured surface demonstrates spreading driven by wicking, droplets which hit the surface with a non-zero impact velocity demonstrate spreading characteristics similar to the smooth surface, which are driven by inertia and ultra-low contact angle. The presence of the nanoporous layer impacts the equilibrium position of the contact line and the final spread radius changes with impact velocity on the nanostructured surface. These results provide fundamental input for modeling of spray cooling systems with nanostructured surfaces.
Numerical Investigation on Thermal and Fluid Dynamic Analysis of a Solar Chimney in a Building Façade
Authors: Buonomo Bernardo , Cascetta Furio , Diana Alessandra , Manca Oronzio , Nardini Sergio
Published: December 2019

Solar chimney is a system to produce energy and it has several applications, such as production of electricity, buildings ventilation, heating and cooling. In this paper, a numerical investigation on a prototypal solar chimney system integrated in a south facade of a building is presented. The chimney is 4.0 m high, 1.5 m wide whereas the thickness at the inlet the channel has a gap equal to 0.34 m and at the outlet it is 0.20 m. The chimney consists of a converging channel with one vertical wall and one inclined of 2°. The analysis is carried out on a three-dimensional model in airflow and the governing equations are given in terms of k-ε turbulence model. The problem is solved by means of the commercial code Ansys-Fluent. Simulations are carried out considering the solar irradiance for assigned geographical location and for a daily distribution. Further, comparison between steady state and transient regimes is examined and discussed. Results are given in terms of wall temperature distributions, air velocity and temperature fields and transversal profiles. Performances are better when heat flux is higher and sun is in front of chimney and a low-emissivity glass improves solar chimney achievements. Analysis in transient regimes confirm results obtained in steady state regime.
Parametric Study of SLM Processing Parameters on In-Situ Residual Stress
Authors: Amoako Emmanuel Duodu , Mensah Patrick , Akwaboa Stephen , Ibekwe Samuel , Li Guoqiang
Published: December 2019

Additive Manufacturing (AM) particularly laser powder-bed fusion, is advancing rapidly in manufacturing industries. Selective laser melting (SLM) also known as 3D-printing has become one of the most recent developed and extensively used techniques for several manufacturing processes. However, processing parameters influence the defect formation mechanisms such as porosities, holes, cracks, incomplete fusion and molten pool configuration during the SLM process of metallic powders. Even though an extensive amount of work have been done in minimizing these defect formations by simply varying processing parameters such as laser power, deposition thickness and scanning speed, it is of great importance to study the heat transfer mechanisms in laser heating process and utilize the optimum process parameters in minimizing the residual stress and strain as well as improving the quality of a manufactured product. In this present work, the authors implement a numerical thermo-mechanical model approach to determine the residual stress and strain in 316L Stainless Steel built samples using a finite element method (FEM) software ANSYS® (Workbench version 19.0). We are able to predict the unsteady temperature distribution of temperature-dependent thermal properties, residual stress and strain as a result of the rapid melting and solidification of 316L Stainless Steel metallic powder with optimized processing parameters. From the simulation result, it is shown that the residual stress decreases with an increase in scanning speed, hatch distance and preheat temperature. However, an increase in melting temperature also increases the residual stress and strain in the simulated 3D built part.
CFD Analysis and Evaluation of Heat Transfer Enhancement of Internal Flow in Tubes With 3D-Printed Complex Fins
Authors: Wei Chao , Vasquez Diaz Gabriel Alexander , Wang Kun , Li Peiwen
Published: December 2019

Additive manufacturing (AM), also known as 3D printing technology, is applied to fabricate complex fin structures for heat transfer enhancement at inner surface of tubes, which conventional manufacturing technology cannot make. This work considered rectangular fins, scale fins, and delta fins with staggered alignment at the inner wall of heat transfer tubes for heat transfer enhancement of internal flows. Designed fin structures are trial-printed using plastic material to exam the printability. Laminar flow convective heat transfer has been numerically studied, and heat transfer performance of the tubes with 3D-printed interrupted fins has been compared to that with conventional straight continued fins. The benefit from heat transfer enhancement and the loss due to increased pumping pressure is evaluated using the total entropy generation rate in the control volume of heat transfer tube. As the conclusion of the study, better heat transfer tubes with 3D-printed internal fins are recommended.
Comparison of Volumetric to Surface Heating for Filament-Fed Laser Heated Additive Manufacturing of Glass
Authors: Capps Nicholas E. , Johnson Jason E. , Landers Robert G. , Bristow Douglas A. , Kinzel Edward C. , Marchi Alexandria N. , Bernardin John D.
Published: December 2019

This paper presents work using a laser-heated fiber-fed technique to deposit fully dense glass. A stationary laser beam is focused on the intersection of a quartz filament with the workpiece. The workpiece is articulated on a precision 4-axis stage. The laser beam continuously melts the glass filament so that its viscosity is low enough to wet and fuse the workpiece. The focus of this paper is to compare volumetric heating of the glass as opposed to surface heat flux. CO2 laser radiation (λ = 10.6 µm) strongly couples to the silica phonon mode (optical penetration depth < 5 µm). This requires printing at very slow rates in order to allow the heat to diffuse from the surface of the glass to the interface of the filament and the workpiece. CO laser radiation (λ = 5.3 µm) provides volumetric absorption because of weaker coupling (optical penetration depth of ∼500 µm for fused quartz). This produces a more uniform temperature profile in the glass filament and supports deposition at greater speeds. The maximum deposition rates for 0.5 and 1.0 mm diameter fused quartz filaments are determined by extrapolating the power required to achieve wetting using both CO2 and CO lasers. The results show that volumetric heating (CO laser) produces surface wetting with significantly lower power. The results are compared to a 1D conduction model which suggests that still greater deposition speeds are possible as the optical penetration depth approaches the filament diameter.
A New Accelerated Approach for Spectral Radiation Calculation Using K Distribution and Discrete Ordinate Methods With Application in Industrial Combustion Systems
Authors: Feldick Andrew M. , Pal Gopalendu
Published: December 2019

The introduction of higher fidelity spectral models into a Discrete Ordinates Method (DOM) RTE solver introduces the challenge of solving the N(N+2) coupled equations in intensity over many spectral points. The inability to store intensity fields leads to a nonlinear increase in computational cost as compared to basic gray models, as the solution in an evolving field must be recalculated at each radiation time step. In this paper an approximate initialization approach is used to a reconstructed values of the intensities. This approach is particularly well suited to spectrally reordered methods, as the boundary conditions and scattering coefficients are gray. This approach leads to more tractable computational time, and is demonstrated using on two industrial scale flames.
A Planar Evaporator Design to Counter Parasitic Heat Flow During Device Startup of a Microscale Loop Heat Pipe
Authors: Dhillon Navdeep S.
Published: December 2019

Due to increasing power densities and decreasing device footprints, thermal management has become an important design requirement in modern electronic devices. Loop heat pipes are phase change-based devices that can absorb and transport large heat fluxes via the latent heat of evaporation of a working fluid. However, these devices are bulky and difficult to miniaturize due to the constraining effect of undesired parasitic heat flow and other thermodynamic considerations of the two-phase flow loop. Here, we present experimental results demonstrating the operation of an ultra-thin microscale loop heat pipe that employs a planar evaporator wick designed to counter the negative effects of parasitic heat flow. Despite the extremely low wick thickness (< 0.5 mm), the device is able to successfully startup, with no apparent observation of a wick dry-out due to parasitic heat flow-induced disruptions of liquid supply to the evaporator. A latent heat flux of approximately 6.7 W/cm2 is absorbed per unit area of the evaporator during the device startup phase.
Molecular Dynamics Simulation on the Friction Properties of Couette Flow With Superhydrophobic Rough Surfaces Under Different Load
Authors: Hu Chengzhi , Tang Dawei , Lv Jizu , Bai Minli , Zhang Xiaoliang
Published: December 2019

To reveal the effect of superhydrophobic rough surface on the friction properties, molecular dynamics simulations are used to study the friction properties of Couette flow. In particular, the influence of load on the flow properties is considered in this work. Results show that there is a critical load (Pcrit), and the friction-reduction properties of superhydrophobic surfaces with stripes are only presented when the load is smaller than the Pcrit. With the decrease in the distance between stripes, the Pcrit is increased. Under a low load, the friction force is increased with increasing the distance between stripes. However, under high load condition we observe an opposite trend. The height of stripe has little impacts on the Pcrit.
Quantitative Experimental Investigation on the Flow Characteristics of Nanofluids in Turbulent Flow
Authors: Lv Jizu , Zhang Zhenxian , Hu Chengzhi , Bai Minli
Published: December 2019

In addition to the increase of thermal conductivity, heat transferring for nanofluids strengthening mechanism also includes the changes of the flow characteristics, therefore it is needed to take an in-depth research on nanofluids flow characteristics. However previous visualization experiment do not quantitatively analyze the change of flow characteristics after nano-particles is added, do not reveal the mechanism of nanofluids changing the characteristics of the fluid in intense turbulent flow condition. Therefore in this paper, by means of particle image velocimetry, quantitatively study SiO2-water nanofluids flow characteristics in intense turbulent flow condition and analyze the influence of SiO2-water nanofluids on turbulent flow energy by measuring the pressure drop caused by fluid flowing through the channel.

Fluid flow through rectangular convex channel (channel composed of continuous staggered rectangular convex platform) to obtain the steady intense turbulent flow. The rectangular convex channel makes the fluid flow through obstacles for several times, so that the flow direction changes for several times, and vortexes are generated in the local scope, which makes turbulence enhance and increases minor loss. In this way, flow can be in the intense turbulent state under a low flow rate, which meets the experiment requirement and is convenient to compare the influence of nano-particles on flow resistance and energy loss. The experiment takes the quantitative PIV experimental research on pure water and the volume fraction of 0.5% SiO2-water nanofluids respectively in the Reynolds number is 2300, 2500, 3000, 4000. Through the experiment, we can obtain nanofluids turbulent flow condition fluctuating velocity, turbulence kinetic, energy loss and so on, and the fluid flow velocity vector, streamline and vorticity graph. Through the quantitative comparison of the spiral numbers, the vorticity distribution, and energy loss, analyze strengthening effect and influence of flow resistance on basic fluid after adding nanoparticles.
PPV Effect on Smoke Movement Through a Shaft in High-Rise Fires: Experiments and CFD Simulation
Authors: Ye Xiaoman , Ezekoye Ofodike A. , He Qize
Published: December 2019

While Positive Pressure Ventilation (PPV) has proven to be effective in high-rise fire-fighting, its effect on smoke movement through a stairwell shafts in high-rise fires is still inconclusive. Towards better understanding of the effects of PPV for smoke transport in high-rise type structures, a 1/4 reduced-scale 7-floor building with dimensions of 1.0 m × 0.5 m × 4.2 m consisting of a vertical shaft and several rooms over a number of floors has been designed and tested. Both experiments and CFD simulations for this model were conducted. It was found that there are several potential PPV tactics that could be useful in high-rise smoke control in fires. In the cases examined, PPV was considered to be applied from outside the building through vents in external rooms of the building. When a PPV fan is applied above the floor containing the fire layer, the pressure induced by the PPV flow should be larger than the pressure difference caused by the stack effect induced by the hot fire product gases. Insufficient PPV flow rates is shown to lead to accumulation of smoke and further increase in the gas temperature within the shaft due to the blocking effect. A better option is applying PPV below the fire floor. With the same pressurization air flow rate, applying PPV from below the fire floor is more effective than applying it from the top of building. In this situation, PPV not only prevents accumulation of the smoke in the shaft, but also prevents smoke from entering the shaft. The results of this study can guide the development of firefighter ventilation tactics for smoke control in high-rise fires.
Liquid Transport During Evaporation of Water From a Small Simulated Soil Column
Authors: Chakraborty Partha Pratim , Ross Molly , Bindra Hitesh , Derby Melanie M.
Published: December 2019

The food-energy-water nexus considers critical resource challenges which must be resolved in order to meet the needs of a growing population. Agriculture is the largest global water user, accounting for two-thirds of global water withdrawals, including water for crop irrigation. Understanding and therefore reducing evaporation of water from soil is an approach to conserve water resources globally. This work studies evaporation of water from a simulated soil column and employs x-ray imaging to determine the location of water in the porous media. A 30-mL beaker was filled with approximately 1700 2-mm hydrophilic glass beads. Water (i.e., 5.5 mL) was added to the simulated soil, comprised of glass beads and a heat flux (i.e., 1500 W/m2) was applied to the beaker using a solar simulator and the intensity was measured with a light meter. Real-time mass measurements were recorded during evaporation and X-ray imaging was utilized to capture liquid transport during evaporation. Images were post-processed using Matlab; the position of the liquid front was determined from this imaging. Across three replications, it took 47 hours on average to evaporate 5 mL of the total 5.5 mL of water. The transitions between evaporation Stage I, II, and III evaporation rates were determined using mass data and x-ray imaging; transition between Stages I and II occurred between approximately 4 and 9 hours, and the transition from Stage II to III evaporation occurred between approximately 18 and 24 hours. The result of this experiment will be useful to understand the liquid transport and formation of liquid bridges during evaporation from soil.
Finite element analysis of round-window stimulation of the cochlea in patients with stapedial otosclerosis
Authors: Zhang Jing , Tian Jiabin , Ta Na , Rao Zhushi
Published: December 2019

An active actuator coupled to the round window (RW) can transmit mechanical vibrations into the cochlea and has become a therapeutic option of hearing rehabilitation for patients with stapedial otosclerosis. A finite-element model of the human ear that includes sound transmission effects of the vestibular and cochlear aqueducts of the inner ear is adopted in this study for investigating the cochlear response to RW stimulation under stapes fixation. There are two effects due to otosclerosis of the stapes: the fixation of the stapedial annular ligament (SAL) and the increase of the stapes mass. The frequency responses of the middle ear and cochlea with normal and otosclerotic stapes are calculated under sound and RW stimulations. The results show that changes in the material property of the stapes have different effects on the cochlear responses under sound and RW stimulations. Because of the vestibuli aqueduct, the reduction in the low-frequency magnitude of the pressure difference across the cochlear partition due to SAL fixation is much smaller under RW stimulation than under sound stimulation. The results of this study help understand sound transmission during RW stimulation in patients with stapedial otosclerosis.
Hypusine biosynthesis in β cells links polyamine metabolism to facultative cellular proliferation to maintain glucose homeostasis
Authors: Levasseur Esther M. , Yamada Kentaro , Piñeros Annie R. , Wu Wenting , Syed Farooq , Orr Kara S. , Anderson-Baucum Emily , Mastracci Teresa L. , Maier Bernhard , Mosley Amber L. , Liu Yunlong , Bernal-Mizrachi Ernesto , Alonso Laura C. , Scott Donald , Garcia-Ocaña Adolfo , Tersey Sarah A. , Mirmira Raghavendra G.
Published: December 2019

β Cell proliferation in response to insulin resistance requires hypusination of an mRNA translation factor.
Biased M
1
receptor–positive allosteric modulators reveal role of phospholipase D in M
1
-dependent rodent cortical plasticity
Authors: Moran Sean P. , Xiang Zixiu , Doyle Catherine A. , Maksymetz James , Lv Xiaohui , Faltin Sehr , Fisher Nicole M. , Bender Aaron M. , Niswender Colleen M. , Rook Jerri M. , Lindsley Craig W. , Conn P. Jeffrey
Published: December 2019

Biased modulators show that long-term depression induced by the M
1
muscarinic acetylcholine receptor requires PLD.
UV Inactivation of Rotavirus and Tulane Virus Targets Different Components of the Virions
Authors: Araud Elbashir , Fuzawa Miyu , Shisler Joanna L. , Li Jianrong , Nguyen Thanh H.
Published: December 2019

UV irradiation is becoming common for disinfection in water treatment plants, but little is known about the effectiveness of this treatment for enteric RNA viruses. Here, we observed that 220-nm UV irradiation was efficacious against rotavirus (RV) and Tulane virus (TV). UV irradiation at 254 nm inactivated TV to a greater extent than RV. Additional assays showed that UV irradiation compromised different portions of the RV and TV life cycles. UV irradiation decreased the binding of TV to its host receptor and mutagenized the TV genome. UV irradiation at 220 nm appeared to allow RV–host receptor interaction but halted RV genome replication. These findings provide knowledge about the disinfection of waterborne viruses, information that is important for the safe reuse or release of treated wastewater.
Profiles of Local and Systemic Inflammation in the Outcome of Treatment of Human Cutaneous Leishmaniasis Caused byLeishmania(Viannia)
Authors: Navas Adriana , Fernández Olga , Gallego-Marín Carolina , Castro María del Mar , Rosales-Chilama Mariana , Murillo Julieth , Cossio Alexandra , McMahon-Pratt Diane , Saravia Nancy Gore , Gómez María Adelaida
Published: December 2019

The immune mechanisms that contribute to the efficacy of treatment of cutaneous leishmaniasis (CL) are not fully understood. The aim of this study was to define immune correlates of the outcome of treatment of CL caused byLeishmania(Viannia) species during standard of care treatment with pentavalent antimonials.
Helicobacter pylori Infections in the Bronx, New York: Surveying Antibiotic Susceptibility and Strain Lineage by Whole-Genome Sequencing
Authors: Saranathan Rajagopalan , Levi Michael H. , Wattam Alice R. , Malek Adel , Asare Emmanuel , Behin Daniel S. , Pan Debra H. , Jacobs William R. , Szymczak Wendy A.
Published: December 2019

The emergence of drug resistance in
Helicobacter pylori
has resulted in a greater need for susceptibility-guided treatment. While the alleles associated with resistance to clarithromycin and levofloxacin have been defined, there are limited data regarding the molecular mechanisms underlying resistance to other antimicrobials. Using
H. pylori
isolates from 42 clinical specimens, we compared phenotypic and whole-genome sequencing (WGS)-based detection of resistance.
The Nesting Doll of Cutibacterium acnes Clonality
Authors: Schuetz Audrey N.
Published: December 2019

In this issue of the
Journal of Clinical Microbiology
, R. E. Bumgarner, D. Harrison, and J. E. Hsu (J Clin Microbiol 58:e00121-19, 2020,
https://doi.org/10.1128/JCM.00121-19
) address in a retrospective analysis that clonality of
Cutibacterium acnes
isolates from deep tissue specimens obtained from patients during revision shoulder arthroplasty cannot be assumed.
Draft Genome Sequences of Two Textile Azo Dye-Degrading Shewanella sp. Strains Isolated from a Textile Effluent in Peru
Authors: Fuentes Ivette , Ccorahua Robert , Tinoco Oscar , León Oscar , Ramírez Pablo
Published: December 2019

Here, we report the annotated genome sequences of two
Shewanella
sp. strains isolated from textile industry wastewater effluent in Peru. Potential genes for encoding enzymes that enable the strain to decolorize and degrade textile azo dyes were detected in both genomes.
Complete Genome Sequences of Two Salmonella enterica subsp.
enterica
Serovar Anatum Strains Isolated from Papaya
Authors: Miller Daniela , Yao Kuan , Whitney Brooke , Sanchez Leon Maria , Tallent Sandra , Hoffmann Maria
Published: December 2019

Salmonella enterica
is a major global foodborne pathogen that causes gastroenteritis and, in some cases, death.
Salmonella
serovar Anatum has been increasingly associated with foodborne salmonellosis outbreaks. In this report, we announce two complete genome sequences of
Salmonella
Anatum isolated from papaya fruit.
Draft Genome Sequence of Aspergillus terreus High-Itaconic-Acid-Productivity Mutant TN-484
Authors: Kanamasa Shin , Minami Tomoyuki , Okabe Mitsuyasu , Park Enoch Y. , Fujimoto Tsukasa , Takahashi Anna , Murase Masataka , Fukuyoshi Shuichi , Oda Akifumi , Satou Kenji , Takahashi Hiro
Published: December 2019

Itaconic acid is an important organic acid used in the chemical industry.
Aspergillus terreus
strain TN-484 is a high-itaconic-acid-productivity mutant derived from strain IFO6365. Here, we report the draft genome sequence of strain TN-484, advancing the understanding of the biosynthesis of itaconic acid in filamentous fungi.
Pre-arrest and intra-arrest prognostic factors associated with survival after in-hospital cardiac arrest: systematic review and meta-analysis
Authors: Fernando Shannon M , Tran Alexandre , Cheng Wei , Rochwerg Bram , Taljaard Monica , Vaillancourt Christian , Rowan Kathryn M , Harrison David A , Nolan Jerry P , Kyeremanteng Kwadwo , McIsaac Daniel I , Guyatt Gordon H , Perry Jeffrey J
Published: December 2019

Objective

To determine associations between important pre-arrest and intra-arrest prognostic factors and survival after in-hospital cardiac arrest.

Design

Systematic review and meta-analysis.

Data sources

Medline, PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systematic Reviews from inception to 4 February 2019. Primary, unpublished data from the United Kingdom National Cardiac Arrest Audit database.

Study selection criteria

English language studies that investigated pre-arrest and intra-arrest prognostic factors and survival after in-hospital cardiac arrest.

Data extraction

PROGRESS (prognosis research strategy group) recommendations and the CHARMS (critical appraisal and data extraction for systematic reviews of prediction modelling studies) checklist were followed. Risk of bias was assessed by using the QUIPS tool (quality in prognosis studies). The primary analysis pooled associations only if they were adjusted for relevant confounders. The GRADE approach (grading of recommendations assessment, development, and evaluation) was used to rate certainty in the evidence.

Results

The primary analysis included 23 cohort studies. Of the pre-arrest factors, male sex (odds ratio 0.84, 95% confidence interval 0.73 to 0.95, moderate certainty), age 60 or older (0.50, 0.40 to 0.62, low certainty), active malignancy (0.57, 0.45 to 0.71, high certainty), and history of chronic kidney disease (0.56, 0.40 to 0.78, high certainty) were associated with reduced odds of survival after in-hospital cardiac arrest. Of the intra-arrest factors, witnessed arrest (2.71, 2.17 to 3.38, high certainty), monitored arrest (2.23, 1.41 to 3.52, high certainty), arrest during daytime hours (1.41, 1.20 to 1.66, high certainty), and initial shockable rhythm (5.28, 3.78 to 7.39, high certainty) were associated with increased odds of survival. Intubation during arrest (0.54, 0.42 to 0.70, moderate certainty) and duration of resuscitation of at least 15 minutes (0.12, 0.07 to 0.19, high certainty) were associated with reduced odds of survival.

Conclusion

Moderate to high certainty evidence was found for associations of pre-arrest and intra-arrest prognostic factors with survival after in-hospital cardiac arrest.

Systematic review registration

PROSPERO CRD42018104795
Influence of sleep problems and co-occurring musculoskeletal pain on long-term prognosis of chronic low back pain: the HUNT Study
Authors: Skarpsno Eivind Schjelderup , Mork Paul Jarle , Nilsen Tom Ivar Lund , Nordstoga Anne Lovise
Published: December 2019

Background

We investigated the influence of sleeplessness and number of insomnia symptoms on the probability of recovery from chronic low back pain (LBP), and the possible interplay between sleeplessness and co-occurring musculoskeletal pain on this association.

Methods

The study comprised data on 3712 women and 2488 men in the Norwegian HUNT study who reported chronic LBP at baseline in 1995–1997. A modified Poisson regression model was used to calculate adjusted risk ratios (RRs) for the probability of recovery from chronic LBP at follow-up in 2006–2008, associated with sleep problems and co-occurring musculoskeletal pain at baseline.

Results

Compared with persons without sleeplessness, persons who often/always experienced sleeplessness had a lower probability of recovery from chronic LBP (RR 0.65, 95% CI 0.57 to 0.74 in women and RR 0.81, 95% CI 0.69 to 0.95 in men). Although there was no clear evidence of statistical interaction between sleeplessness and co-occurring musculoskeletal pain, women and men who often/always experienced sleeplessness and had ≥5 additional chronic pain sites had RRs of recovery of 0.40 (95% CI 0.33 to 0.48) and 0.59 (95% CI 0.45 to 0.78), respectively, compared with persons without sleeplessness and 1–2 chronic pain sites.

Conclusion

These findings suggest that preventing or reducing sleep problems among people with chronic LBP may have the potential of improving the long-term prognosis of this condition, also among those with several additional pain sites.
Geology, mineralogy, S and Sr isotope geochemistry, and fluid inclusion analysis of barite associated with the Lemarchant Zn–Pb–Cu–Ag–Au-rich volcanogenic massive sulphide deposit, Newfoundland, Canada
Authors: Lajoie Marie-Ève , Piercey Stephen J. , Conliffe James , Layton-Matthews Daniel
Published: December 2019

Barite in the approximately 513 Ma Lemarchant volcanogenic massive sulphide (VMS) deposit, Newfoundland, consists of granular and bladed barite intimately associated with mineralization. Regardless of type, the composition of barite is homogeneous at bulk rock and mineral scale containing predominantly Ba, S, and Sr, with minor Ca and Na. The barite has homogeneous sulphur isotope compositions (δ34Smean = 27‰), similar to Cambrian seawater sulphate (25–35‰) and Sr isotope compositions (87Sr/86Sr = 0.706905 to 0.707485). These results are consistent with barite having formed from fluid–fluid mixing between Cambrian seawater and VMS-related hydrothermal fluids. The 87Sr/86Sr values in the barite are lower than mid-Cambrian seawater, which suggests that some of the Sr was derived from the underlying Neoproterozoic basement. Fluid inclusions in bladed barite are low-salinity, CO2-rich inclusions with homogenization temperatures between 245°–250 °C, and average salinity of 1.2 wt.% NaCl equivalent. Estimated minimum trapping pressures of between 1.7 to 2.0 kbars were calculated from aqueous–carbonic fluid inclusion assemblages. The fluid inclusion results reflect regional metamorphic reequilibration during younger Silurian regional metamorphism, rather than primary fluid signatures, despite the preservation of primary barite and fluid inclusion textures. These results illustrate that barite in VMS deposits records the physicochemical processes associated with VMS formation and the sources of fluids in ancient VMS deposits, as well as seawater sulphate and basement isotopic compositions. The results herein are not only relevant for the Lemarchant deposit but also for other barite-rich VMS deposits globally.
Unmanned aerial vehicles can accurately, reliably, and economically compete with terrestrial mapping methods
Authors: Thomas Orrin , Stallings Christian , Wilkinson Benjamin
Published: December 2019

Structure from motion (SfM) and imagery-derived point clouds (IDPC) are excellent tools for collecting spatial data. However, reported accuracies from unmanned aerial systems (UAS) commonly fall short of their theoretical potential. The research presented here, using a DJI Inspire 2 with post-processed kinematic direct geopositioning, demonstrates that UAS mapping can be consistently accurate enough for use in place of, or in concert with, terrestrial methods (2 cm vertical root mean squared error). We further demonstrate that features that are missing or distorted in IDPC (e.g., roof edges, break lines, and above-ground utilities) can be collected from UAS-imagery stereo models with similar accuracy. Accuracy in the experiments was verified by comparison to data from a total station and terrestrial laser scanner (TLS). Use of the recommended hardware and stereo compilation reduced mapping costs by 40%–75% on three test projects.
Using Traditional Chinese Medicine to Relieve Asthma Symptoms: A Systematic Review and Meta-Analysis
Authors: Wang Mei-Hua , Chen Chiehfeng , Yeh Mei-Ling , Lin Jaung-Geng
Published: December 2019

Studies have demonstrated the effect of acupoint-based interventions in relieving the clinical symptoms of asthma. However, the effect of meridian-based interventions in asthma symptom relief is unknown. This systematic review and meta-analysis determined the effect of multiplex meridian interventions in asthma symptom relief. Eight electronic databases were searched for relevant randomized controlled trials (RCTs) that involved patients with asthma, were published before March 2018, used acupoint stimulation interventions targeting acupoints that correspond to meridians, and considered asthma symptom relief as an outcome. In 204 RCTs that were identified and used in a meta-synthesis, meridians were used 521 times, with the bladder meridian being the most frequently used. Furthermore, 23 RCTs were included in the meta-analysis. Egger’s and inconsistency tests revealed no significant differences among the studies ([Formula: see text]). However, the interventions differed significantly in terms of asthma symptom relief effect, as demonstrated by pairwise (odds ratio [Formula: see text], 95% confidence [Formula: see text]–0.37) and network ([Formula: see text], 95% credibility [Formula: see text]–0.41) meta-analyses. Surface under the cumulative ranking (SUCRA) revealed that the bladder–conception vessel–governor vessel–stomach multiplex meridian intervention was more effective than non-meridian interventions in relieving asthma symptoms. Additionally, either bladder–conception vessel–stomach or bladder–conception vessel–governor vessel–kidney multiplex meridians may be selected in interventions. This study suggests that practitioners target multiplex meridians, especially the meridians of the bladder and conception vessel, to effectively relieve asthma symptoms.
How Ginsenosides Trigger Apoptosis in Human Lung Adenocarcinoma Cells
Authors: Xiao Han , Xue Qianfei , Zhang Qinghua , Li Chunyan , Liu Xiaoqiu , Liu Jing , Li Han , Yang Junling
Published: December 2019

Panax ginseng is a natural medicine that has been used globally for a long time. Moreover, several studies have reported the effective activity of ginseng in treating malignancies. Various agents containing ginseng were widely used as an antitumor treatment nowadays. Lung cancer is the most common fatal cancer in China, and lung adenocarcinoma is the most common histological type of non-small cell lung cancer (NSCLC). What’s worse, many patients may have a failed response to conventional therapy including chemotherapy, radiotherapy, or molecule-targeted therapy due to drug resistance. Apoptosis is a highly ordered cellular suicidal process that plays an essential role in maintaining normal homeostasis. The pharmacological mechanism of many antineoplastic drugs involves triggering of apoptotic process. In several recent studies, ginsenosides are regarded as major active components of ginseng that have the potential to control lung cancer. Most of these results have proved that ginsenosides induce apoptosis in lung cancer cells through many different signaling pathways such as PI3K/Akt, NF-[Formula: see text]B, EGFR, and so on. This study is aimed at reviewing the signaling pathways that underlie ginsenosides-triggered apoptotic process and encourage further studies to target promising agents against lung cancer treatment.
Electrically tunable graphene-based metamaterials: A brief review
Authors: Huynh Tran Van , Tung Bui Son , Khuyen Bui Xuan , Tung Nguyen Thanh , Lam Vu Dinh
Published: December 2019

Metamaterials (MMs) represent a group of exciting artificial materials that interact with electromagnetic waves in unnatural ways. The motivation behind MM research arises not only from fundamental interest in their unique physical properties but also from the desire of creating smarter materials for advanced technological applications. Despite an abundance of studies on numerous shapes, sizes and operating frequencies, the use of conventional metal-dielectric components makes the post-fabrication physical properties of MMs unalterable. Therefore, the integration of other nonlinear materials is necessary for exploring the functional limits of MMs. In this regard, a mono-layer of carbon, the so-called graphene, with its unique electrical conductivity is identified as a promising candidate. This review discusses the recent progress on tunable graphene-based THz MMs for perfect absorption and electromagnetically-induced transparency effects. A short overview of prospect challenges and tendencies is also given for future development of graphene-integrated MMs towards upcoming smart meta-devices.
Quantum correlation and non-classical properties in semiconductor microcavities for multi-photon excitation
Authors: Abdel-Khalek S. , Berrada K. , Eleuch H.
Published: December 2019

We study how the interplay of weak excitation regime of quantum well confined in a semiconductor microcavity affects the dynamics of correlations and the statistical properties of photons. We discuss how the system parameters can impact the quantum entropy and Mandel’s parameter, and illustrate our concerns with numerical simulations. We have found that the enhancement of the correlations and the control of the statistical properties of photons in semiconductor microcavities for multi-photon excitation highly benefits from the combination of the strength of the field, excitonic spontaneous emission rate, cavity dissipative rate, and the coupling between the exciton and photons. Our results may have important implications not only for those specially interested in quantum optics and information, but also for the general physics community.
EVALUATING THEORIZATIONS OF INFORMAL SECTOR ENTREPRENEURSHIP: SOME LESSONS FROM ZAMFARA, NIGERIA
Authors: LADAN USMAN , WILLIAMS COLIN C.
Published: December 2019

The aim of this paper is to evaluate critically four competing theories that variously explain informal sector entrepreneurship as a traditional activity that has not yet been incorporated into the modern system (modernization theory), a form of production integral to contemporary capitalism conducted by marginalized population groups as a survival strategy (structuralist theory), a voluntarily chosen endeavor and popular reaction to excessive regulation by the state (neo[Formula: see text]liberal theory) or a voluntarily chosen practice conducted for social, redistributive, political resistance or identity reasons (post-structuralist theory). Reporting the results of face[Formula: see text]to[Formula: see text]face interviews with 215 informal entrepreneurs in Zamfara, a tropical region in Nigeria, the finding is that no one theory is universally valid. Instead, each theory is valid in relation to different groups of entrepreneur and only by combining all of them can a finer-grained and more nuanced explanation of the complex and heterogeneous character of informal sector entrepreneurship be achieved.