bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Pool Boiling Heat Transfer on Concave Nanostructured Surface With Molecular Dynamics Simulation
Authors: Liu Runkeng , Liu Zhenyu , Wu Huiying
Published: December 2019

The nanoscale boiling phenomena on solid surface is significantly distinct from that at macroscale. In this work, the pool boiling process of liquid argon thin film on smooth/concave aluminum surfaces were simulated using non-equilibrium molecular dynamics (NEMD) simulation, in which the nonuniform hydrophilic/hydrophobic surfaces were considered. For each surface, the superheat degree was progressively increased and the MD simulations were carried out to record the variation of atomic motion trajectory, mass density, the number of vapor and liquid atoms, kinetic energy and internal energy as time elapses. The predictions show that heat flux can reach critical heat flux (CHF) with increasing of wall superheat degree. Under the same superheat degree, the hydrophilic surface has the higher heat flux value than the hydrophobic surface, but it is earlier to reach CHF compared to the hydrophobic one. In addition, it also demonstrates that, with the same surface morphology, liquid-solid interaction strength has a significant influence on the heat transfer transition from nucleate boiling to film boiling. The surface morphology has more favorable effect on the pool boiling compared to the surface wettability at nanoscale. The obtained results in this work can guide the design and fabrication of enhanced heat transfer surface with nanostructured modification.
Wettability Effects on Falling Film Heat Transfer Over Horizontal Tubes in Jet Flow Mode
Authors: Karmakar Avijit , Acharya Sumanta
Published: December 2019

The performance of a falling-film heat exchanger is strongly linked to the surface characteristics and the heat transfer processes that take place over the tubes. The primary aim of this numerical study is to characterize the influence of surface wettability of tubes on the falling film flow mode and its associated surface heat transfer. Surface wettability is generally characterized by the contact angle and, in this study, the wettability characteristics ranged from superhydrophilic to a superhydrophobic tube surface. The dynamic motion of the triple contact line connecting the solid, liquid and gas phases over the tube surface is replicated with the help of the Kistler’s dynamic contact angle model. The volume of Fluid (VOF) simulations was carried out for the flow and heat transfer of liquid flow over horizontal tubes with different surface wettabilities. The mass flow rate is such that the flow is in the jet mode where the liquid flows in the form of jets in between the horizontal tubes. This corresponds to a liquid mass flow rate per unit tube length of 0.06 and 0.18 Kg/m-s, under which the inline and staggered jets modes of flow are observed. Under the two flow rates and different surface wettabilities, the liquid flow hydrodynamics over the tube surfaces was explored in terms of the liquid film thickness, the contact areas (solid-liquid and liquid-air) between the different phases, and the heat transfer coefficient. The axial resistance imposed by the increasing contact angle tends to inhibit the extent of the liquid spreading over the tube surface and this, in turn, influences the liquid film thickness and the wetted area of the tube surface. A significant decrement in the heat transfer rate from the tube surfaces was observed as the equilibrium contact angle ranged from 2° to 175°. Heat transfer characteristics were quantified over a wide range of contact angles for the two mass flow rates. Fluid recirculations were observed in the liquid bulk which had a major impact on the heat transfer distribution over the tube surface.
Modified Manifold-Microchannel Heat Exchangers Fabricated Based on Additive Manufacturing: Experimental Characterization
Authors: Yameen William C. , Piascik Nathan A. , Miller Andrew K. , Clemente Riccardo C. , Benner Jingru Z. , Santamaria Anthony D. , Niknam Seyed A. , Mortazavi Mehdi
Published: December 2019

In this study, the additive manufacturing technique has been utilized to fabricate air-water heat exchangers for the application of thermoelectric power plants. Additive manufacturing is a powerful fabrication method that has enabled fabrication of complex geometries that are either challenging or impossible to fabricate based on conventional techniques. Three manifold-microchannel heat exchangers with different interior designs were fabricated by additive manufacturing and from stainless steel. The heat exchangers were tested at different air flow rates and different inlet water temperatures. One heat exchanger was designed and fabricated based on an original design of the manifold-microchannel heat exchanger. Two other heat exchangers were designed with some modifications compared to the original design. In one modified heat exchanger, cylindrical pin arrays were considered on air manifold walls in order to enhance air disturbance, and thus, increase heat transfer between water and air. The second modified heat exchanger contained same pins and also had microchannels in the perpendicular orientation compared to the original design in the outlet manifolds. This design modification was done in order to reduce air-side pressure drop in the heat exchanger. The heat transfer characteristics along with air-side pressure drop were measured and compared with the original design of the manifold-microchannel heat exchanger. Results indicated that the heat flow rate, convection heat transfer coefficient, and pressure drop did not significantly change in modified heat exchangers. For air Reynolds number between around 800 and 4,000, the heat flow rates obtained in the original heat exchanger (type A) and for 50° C water inlet temperature were between 63.9 and 228 W for the lowest and the highest air flow rates, respectively. For the same inlet water temperature, these heat flow rates were between 64.2 and 211 W for the lowest and the highest air flow rates and in one of the modified heat exchangers (type B), respectively. Similarly, while the highest air-side pressure drop in the original heat exchanger was 3458 Pa, this property was measured at 3525 (type B) and 3884 (type C) for the two modified heat exchangers.
Comparison of Droplet Evaporation and Nucleate Boiling Mechanisms on Nanoporous Superhydrophilic Surfaces
Authors: Cabrera Samuel , Carey Van P.
Published: December 2019

Recent studies have indicated that at slightly superheated surface temperatures, droplet evaporation on a nanoporous superhydrophilic surface exhibits onset of nucleation and nucleate boiling effects similar to pool boiling processes. This paper discusses water droplet evaporation experiments and pool boiling experiments conducted on nanostructured surfaces of a 45° downward facing pyramid copper and aluminum substrate. The nanostructured surfaces were used to conduct both droplet evaporation experiments and pool boiling experiments and thus allow direct comparison of the underlying heat transfer performance and mechanisms for these two different processes. The four surfaces tested were the following: bare copper surface, nanostructured surface on copper, bare aluminum surface, and nanostructured surface on aluminum. Mean heat flux values at varying superheats were obtained through temperature and time measurements. To better understand the heat performance of each surface, the wetting and wicking characteristics of each surface were also tested. Experimental results indicate that many of the mechanisms associated with pool boiling may also play a role in droplet vaporization, and their presence can produce levels of heat transfer performance comparable to, or even higher than, that observed in pool boiling at a comparable wall superheat. The results demonstrate that the nanostructured surface affects onset of nucleate boiling and maximum heat flux in both droplet vaporization and nucleate boiling on these surfaces. The implications of these results for strategies to enhance spray cooling and pool boiling are also discussed.
Influence of Overweight Acceleration on Heat Transfer of Hydrocarbon Fuel in a Vertical Tube at Supercritical Pressures
Authors: Lv Lulu , Fu Yanchen , Dong Bensi , Wen Jie , Xu Guoqiang
Published: December 2019

The presented study numerically investigated the heat transfer characteristics of supercritical hydrocarbon fuel RP-3 in a vertical tube under overweight conditions with gravitational accelerations from 1g to 5g. The model was simplified as a vertical tube with the diameter of 1.8mm and the length of 250mm. Constant heat flux was applied to the wall, varying from 200kW/m2 to 700kW/m2. Variations of wall temperature and heat transfer coefficient under overweight conditions were obtained by simulation. The dimensionless buoyancy and thermal acceleration under different conditions were analyzed. The results show that the heat transfer is normal at low heat flux, while two types of heat transfer deterioration were observed in both upward and downward supercritical flow at high heat flux. The heat transfer coefficient of downward flow is generally higher than upward flow, and the difference between them becomes larger with the increase of gravitational acceleration. At high heat flux, when bulk temperature reaches the pseudo-critical temperature, the thermal acceleration will increase by 50% leading to the deterioration of heat transfer. However, after the pseudo-critical point, both buoyancy force and thermal acceleration decrease to negligible. The rise in gravitational acceleration enhances buoyancy force, but has no impact on the thermal acceleration. Based on the numerical analysis, two different criterion, Bo* and Kv, for supercritical RP-3 are obtained to present the influence of buoyancy and thermal acceleration.
Numerical Study of Gas-Liquid Two-Phase Flow in Ultra-High-Aspect-Ratio Microchannel With Capillary-Structured Wall
Authors: Mei Xiang , Liu Zhenyu , Wu Huiying
Published: December 2019

The understanding of the liquid-gas flow and heat transfer in the high-aspect-ratio microchannel is very important to realize the high-efficiency phase change chip cooling. In this work, a novel ultra-high-aspect-ratio microchannel with capillary-structured wall was developed to enhance the evaporation heat transfer in microchannel, in which the capillary grooves on the side walls (capillary-structured wall) were designed to avoid the dryout phenomenon. A three-dimensional VOF model was established to predict the immiscible gas-liquid flow in microchannel. The influences of wettability of capillary grooves on the gas-liquid two-phase flow behavior in microchannel were investigated based on the numerical predictions. The slug bubble can be observed for different inlet flow conditions. Variation of pressure loss between inlet and outlet of microchannel with time were studied for different flow rates and gas-liquid ratios. The results show that the existence of capillary structured wall has a significant influence on the liquid-gas two-phase flow behavior in the microchannel. The liquid flow in microgrooves is driven by the capillary force, which can supply more liquid to the side wall to promote the evaporation heat transfer process. The design of capillary-structured wall for ultra-high-aspect-ratio microchannel in this work provides a new approach to improve the performance of the chip cooling technique with microchannels.
The Effect of Forced Convection on Mass and Heat Transfer During Single Coal Particle Combustion
Authors: Feng Lele , Zhang Yang , Wu Yuxin , Xu Kailong , Zhang Hai , Zhang Man , Yang Hairui
Published: December 2019

MILD coal combustion is one of promising technologies for clean coal utilization due to uniform heat flux and low NOx emission, while the effect of turbulent mixing on single coal particle combustion under high temperature and low oxygen concentration remains to be studied for micron level particles. In this paper, a 1-D transient coal combustion model was applied to describe mass and heat transfer around a single particle, and the effect of forced convection was modeled to represent turbulent mixing according to similarity analysis. Based on that, effect of particle Reynolds number (Rep) on single coal particle combustion was investigated at various temperature (Ta), oxygen concentration (xO2) and particle diameter (d0). As Rep increases, ignition time (ti) decreases quickly at first and then decreases slowly. ti of larger particle is more sensitive to Rep. As Rep increases, flame temperature (Tf) for 40 μm coal particle decreases, while Tf for 80 μm coal particle barely changes, and that for 160 μm coal particle increases a little. The recommended d0 for MILD coal combustion is smaller than 80 μm. As xO2 decreases from 21% to 5%, ti apparently increases and Tf decreases. ti at lower Ta is more sensitive to Rep. Tf decreases with increasing Rep when Ta < 1200 K. But it appears the opposite trend at Ta = 1600 K. The recommended Ta for MILD coal combustion is lower than 1400 K, while it cannot be too low considering the burnout of char particle.
The Effects of 3D Printing Parameters and Surface Roughness on Convective Heat Transfer Performance
Authors: Pereira Lucas , Letcher Todd , Michna Gregory J.
Published: December 2019

Additive manufacturing technology and applications have quickly expanded into many industries over the last several years. Improvements in resolution, strength, and material options have helped propel further growth of the industry. This study focuses on an additive manufacturing technology called fused filament fabrication (FFF). FFF involves the extrusion and layer-by-layer deposition of a molten thermoplastic material to create the desired part. One potential new application of FFF is the manufacture of heat exchangers and heat sinks. This study focuses on developing baseline experimental data related to convective heat transfer coefficients over surfaces of commonly used polymers in FFF 3d printing while varying printing parameters. Samples with layer heights (LH) of 0.1 mm, 0.2 mm and 0.3 mm were printed. As the layer height increases, the surface roughness also increased. Sample 1 of LH = 0.1 mm had a roughness of 9.72 μm and at a Reynolds number of 13,200 had a heat transfer coefficient of 72.2 W/m2-K and sample 1 of LH = 0.3 mm had a roughness of 28.83 μm and at a Reynolds number of 13,600 had a heat transfer coefficient of 84.6 W/m2-K.
Model and Sensitivity Analysis of the Reciprocating Biomass Conversion Reactor (RBCR)
Authors: Adhikari Roshan , Parziale Nick J.
Published: December 2019

The capabilities of a pilot-scale reciprocating biomass conversion reactor (RBCR) and its sensitivity to changes in various input parameters are examined. The RBCR is a 4-stroke diesel engine repurposed as a novel reactor to produce bio-oil by fast-pyrolysis of biomass. An external source powers the RBCR through the intake, compression/heating, expansion and exhaust strokes. Biomass is carried to the RBCR by an inert gas and is converted during compression as part of the compression work provides the heat of pyrolysis. A control-volume energy balance is coupled with a biomass decomposition mechanism from literature to predict the evolution of bio-products during compression and expansion strokes. The RBCR calculations are compared to experimental results from the state of the art considered to be a lab-scale fluidized-bed reactor (FBR). Calculations predict that the RBCR will increase the biomass throughput, and decrease the energy requirement for biomass conversion with a 6.8 times return on energy investment. The sensitivity analysis indicates the need for finely pulverized biomass for significant conversion, and highlights the versatility of the RBCR since operation parameters can be adjusted to achieve near complete conversion to bio-gas or to yield bio-oil up to 70% of biomass weight.
Heat Transfer Characteristics of a Phase Change Material Fluid in Microchannels Under Pulsating Flow Condition
Authors: Shuvo Abdul Aziz , Morshed AKM M. , Emon Md. Shariful Alam , Tikadar Amitav , Paul Titan C.
Published: December 2019

In this study numerical investigation has been conducted employing pulsating flow in a MicroChannel Heat Sink (MCHS) with phase change material (N-eicosane) as the coolant. The numerical investigation was conducted with H1 boundary condition and laminar pulsating flow condition using commercial software FLUENT. Heat transfer and pressure drop characteristics of the MCHS was calculated for the PCM with different amplitude and frequency of the pulsation and compared with that of the water and PCM under constant velocity flow. Heat transfer performance of the MCHS for both the PCM fluid and water increases for the pulsating flow and it increases with the amplitude of the pulsation; however, pressure drop in case of pulsating flow of PCM fluid remains same compared to the steady flow of PCM. Simulation also has been repeated in this study for two different aspect ratio of the channel.
Numerical Analysis of Heat Transfer in a Laminar, Submerged, Slot Jet Impinging on an Oscillating Wall
Authors: Ragunathan Srivathsan , Goering Douglas J.
Published: December 2019

Numerical simulation results of flow and heat transfer resulting from a confined, submerged liquid jet impinging on a planar oscillating surface are presented here. Laminar jets are employed in places where space and pumping capacity constraints exist (for example, in electronics cooling). However, in a laminar single jet, the cooled region due to the jet is small and is concentrated in the stagnation zone. One way to potentially enhance the heat transfer in a laminar jet impingement arrangement is by oscillating the heated impingement surface. This work extends the previous fluid dynamics analysis (by the same author) by a description and quantification heat transfer in such an arrangement. The problem is studied with respect to two parameters governing jet impingement :Jet Reynolds Number, distance from the jet inlet to the impinging wall (z/d ratios) and a parameter characterizing oscillation : the oscillatory peak Reynolds Number. OpenFOAM (foam-extend 3.2), an open-source CFD code based on the finite volume method is used to solve the problem. Quantification of discretization uncertainty is done by employing the Grid Convergence Index Method (GCI). The transport of the vortex structures formed due to the confined arrangement of the jets and due to the oscillation of the target wall has a strong influence on the temperature distribution on the target surface. The enhancement in heat transfer is estimated as a ratio of the Nusselt Numbers cases with oscillation to corresponding cases without oscillation. It is shown that the heat transfer enhancement is a strong function of the jet and the oscillatory parameters considered.
Experimental Study of Brine Droplet Evaporation and Crystallization at Various Temperatures and Humidity Using EDB Method and Pendant Droplet Method
Authors: Qu Jie , Escobar Luis , Rao Zhonghao , Xu Ben
Published: December 2019

In this study, both electro-dynamic balance (EDB) method and pendant droplet method were employed to study the evaporation and crystallization process of brine droplet. The EDB setup was used to levitate the charged micrometer sized droplets to study the evaporation process. The pendant droplet method could hang millimeter sized droplet to study the crystallization process. The evaporation of brine droplets with different mass concentrations was visualized by a high speed camera under different temperatures and relative humidity in the test chamber. The results showed that EDB method could get the accurate droplet evaporation results which obeyed the classic D2-law. It was found that the evaporation was increased with the decrease of relative humidity. Due to the attractive force provided by sodium and chloride ion on water molecules, evaporation rate of brine droplet was smaller than pure water, therefore the evaporation rate decreased with the increase of mass concentration by showing a linear relationship. In addition, a salt shell could be formed at the outside of droplet which still contained some amount of salt solution inside. Consequently, the water molecules need to overcome the pressure difference inside and outside the salt shell, and diffuse through the shell for further evaporation. For a higher relative humidity, a more round shell would be formed during the evaporation, and the growth of crystallization along the filament is weaker than that of smaller relative humidity. We hope this study can provide a different perspective to the heat transfer community about the evaporation of brine droplet.
Theoretical Modeling of Thermal Transients in a PCM Substrate During Drop Impact
Authors: Quon Andrew , Khan Abdul Ahad , Dhillon Navdeep Singh
Published: December 2019

The physics of transient behavior of liquid drops impacting hot and cold surfaces is of significance in many different applications such as spray cooling, condensation and aircraft icing, and analogous to the process of bubble formation and departure in boiling. The resulting local thermal transients in these processes are primarily dictated by passive parameters such as substrate and liquid thermal properties and flow conditions. We are exploring the use of a surface-embedded phase change material (PCM) to actively manipulate these thermal transients as a means to enhance overall heat transfer performance. The thermal effect of the embedded PCM can be parametrically studied using controlled drop impact experiments. In this work, we perform an analytical and numerical study to model the effect of a liquid drop impacting a hot PCM-embedded substrate. By solving an analytical heat transfer solidification problem, we study the effect of PCM properties and PCM initial temperature on the thermal transients encountered during drop impact. Further, we validate the numerical analysis by showing agreement with experimental results.
Effect of a High Electric Field on the Thermal and Phase Change Characteristics of an Impacting Drop
Authors: Basavanna Abhishek , Khapekar Prajakta , Dhillon Navdeep Singh
Published: December 2019

The effect of applied electric fields on the behavior of liquids and their interaction with solid surfaces has been a topic of active interest for many decades. This has important implications in phase change heat transfer processes such as evaporation, boiling, and condensation. Although the effect of low to moderate voltages has been studied, there is a need to explore the interaction of high electric fields with liquid drops and bubbles, and their effect on heat transfer and phase change. In this study, we employ a high speed optical camera to study the dynamics of a liquid drop impacting a hot substrate under the application of high electric fields. Experimental results indicate a significant change in the pre- and post-impact behavior of the drop. Prior to impact, the applied electric field elongates the drop in the direction of the electric field. Post-impact, the recoil phase of the drop is significantly affected by charging effects. Further, a significant amount of micro-droplet ejection is observed with an increase in the applied voltage.
Heat and Mass Transfer Characteristics of Vapor Permeation in Sweeping Gas Membrane Distillation Systems for Sea Water Desalination
Authors: Alqsair Umar F. , Alwatban Anas M. , Alghafis Abdullah A. , Alshwairekh Ahmed M. , Oztekin Alparslan
Published: December 2019

Computational fluid dynamics simulations are conducted to study the performance of the sweeping gas membrane distillation module (SGMD) for seawater desalination process. The main objective of this work is to study the effect of membrane properties on the membrane flux performance and temperature and concentration polarization characteristics of the module. CFD simulations are conducted in a three-dimensional module to characterize the steady-state velocity, temperature and concentration field in the feed and permeate channel. The Reynolds number for the feed and the permeate stream are set to 900 and 2000, and thus the laminar flow model is adapted for each channel. The effects of the porosity and the membrane thickness are varied while the pore size is fixed for the parametric study. It is revealed that the membrane thickness has a profound influence while the membrane porosity has a slight influence on the SGMD performance. We observed a high level of temperature polarization within the module, which adversely affects the system performance. Remedies for mitigating temperature polarization should be considered for future studies.
Simulations of Film Cooling Flow Structure and Heat Transfer in the Near Field of Cooling Jets With a Modified DES Model
Authors: Yu Feiyan , Yavuzkurt Savas
Published: December 2019

Simulations of film cooling in the near field (x/D < 15) of coolant jets on a flat plate are carried out with detached eddy simulation (DES) and modified DES models. The time-averaged unsteady film cooling effectiveness is compared with experimental data. Both models use two-layer zonal model for near-wall treatment. The near field critical turbulent flow behaviors such as mainstream entrainment, spanwise spreading of counter rotating vortex pair (CRVP), and vortical structure evolutions are predicted and analyzed by DES and modified DES in this study. Modified DES model differs from the DES by implementing an increased eddy viscosity in the spanwise direction to enhance spanwise-diffusion of film cooling jets. Detailed comparisons of DES and modified DES modeling results are made under density ratios of 2.0, 1.6, 1.2 and blowing ratio of 1.0 for a single hole. Modified DES model predicts a wider spanwise spreading of temperature field and film cooling effectiveness. In a comparison of spanwise-averaged film cooling effectiveness with experimental data, DES and modified DES models predict 14.8% and 10.4% deviations under density ratio of 2.0. For density ratio of 1.2, the DES and modified DES results deviate from data 24.5% and 14.7% respectively. Then simulation of film cooling with a three hole domain is also carried out. Instantaneous effectiveness results show that the jets from nearby film cooling holes start to interact with each other before x/D < 10. When the interactions of flow from film cooling holes next to each other are strong, simulations using several cooling holes are meaningful and the current study shows the difference of multi hole and single hole simulations.
Robust far-field subwavelength imaging of scatterers by an acoustic superlens
Authors: Dong Yongkang , Yu Gaokun , Wang Ning
Published: December 2019

It is well accepted that the conversion of an evanescent wave into a propagating wave is critical to far-field subwavelength imaging. However, subwavelength resolution can also be achieved using the multiple signal classification (MUSIC) algorithm for the situation of low conversion. In order to explore the difference of imaging performance between these two approaches, an acoustic superlens of length about one wavelength is designed to convert the evanescent wave into a propagating wave, which can be harnessed by the MUSIC algorithm. It is confirmed that the conversion of the evanescent wave into a propagating wave plays a role in improving the imaging resolution against noise, and the imaging resolution is improved by both the MUSIC algorithm and an acoustic superlens.
Genomic architecture of parallel ecological divergence: Beyond a single environmental contrast
Authors: Morales Hernán E. , Faria Rui , Johannesson Kerstin , Larsson Tomas , Panova Marina , Westram Anja M. , Butlin Roger K.
Published: December 2019

A common genomic architecture allowed a marine snail to rapidly adapt to heterogeneous environments in a replicated way.
The interaction of ceramide 1-phosphate with group IVA cytosolic phospholipase A
2
coordinates acute wound healing and repair
Authors: MacKnight H. Patrick , Stephenson Daniel J. , Hoeferlin L. Alexis , Benusa Savannah D. , DeLigio James T. , Maus Kenneth D. , Ali Anika N. , Wayne Jennifer S. , Park Margaret A. , Hinchcliffe Edward H. , Brown Rhoderick E. , Ryan John J. , Diegelmann Robert F. , Chalfant Charles E.
Published: December 2019

Lipid-regulated production of eicosanoids by cPLA
2
α directs the behaviors of dermal fibroblasts during wound repair.
The long and short of antiviral activity
Authors: Williams Erin R.
Published: December 2019

Only short isoforms of the pseudoenzyme PARP13 inhibit interferon responses.
Biogenesis of the SpaciousCoxiella-Containing Vacuole Depends on Host Transcription Factors TFEB and TFE3
Authors: Padmanabhan Bhavna , Fielden Laura F. , Hachani Abderrahman , Newton Patrice , Thomas David R. , Cho Hyun-Jung , Khoo Chen Ai , Stojanovski Diana , Roy Craig R. , Scott Nichollas E. , Newton Hayley J.
Published: December 2019

Coxiella burnetiiis an obligate intracellular bacterial pathogen that replicates inside the lysosome-derivedCoxiella-containing vacuole (CCV). To establish this unique niche,C. burnetiirequires the Dot/Icm type IV secretion system (T4SS) to translocate a cohort of effector proteins into the host cell, which modulate multiple cellular processes.
Elevated Levels of Interleukin-27 in Early Life Compromise Protective Immunity in a Mouse Model of Gram-Negative Neonatal Sepsis
Authors: Seman Brittany G. , Vance Jordan K. , Rawson Travis W. , Witt Michelle R. , Huckaby Annalisa B. , Povroznik Jessica M. , Bradford Shelby D. , Barbier Mariette , Robinson Cory M.
Published: December 2019

Neonates are at increased risk for bacterial sepsis. We established that the immune-suppressive cytokine interleukin-27 (IL-27) is elevated in neonatal mice. Similarly, human cord blood-derived macrophages express IL-27 genes and secrete more cytokine than macrophages from adults. In the present work, we hypothesized that increased levels of IL-27 predispose neonatal mice to more severe infection during Gram-negative sepsis. Serum IL-27 levels continued to rise during infection.
Functional Perturbation of Mucosal Group 3 Innate Lymphoid and Natural Killer Cells in Simian-Human Immunodeficiency Virus/Simian Immunodeficiency Virus-Infected Infant Rhesus Macaques
Authors: Hueber Brady , Curtis Alan D. , Kroll Kyle , Varner Valerie , Jones Rhianna , Pathak Sachi , Lifton Michelle , Van Rompay Koen K. A. , De Paris Kristina , Reeves R. Keith
Published: December 2019

Vertical transmission of HIV from mother to child accounts for many of the new cases seen worldwide. There is currently no vaccine to mitigate this transmission, and there has been limited research on the effects that lentiviral infection has on the innate immune system in oral tissues of infected children. To fill this knowledge gap, our laboratory studied infant rhesus macaques to evaluate how acute SIV/SHIV infections impacted ILC3 and NK cells, which are immune cells critical for mucosal homeostasis and antimicrobial defense. Our data revealed that SIV/SHIV infection led to a depletion of ILC3 and an increase of NK cells and to a functional shift from a homeostatic to a multifunctional proinflammatory state. Taking the results together, we describe how lentiviral infection perturbs the oral and gastrointestinal mucosae of infant macaques through alterations of resident innate immune cells giving rise to chronic inflammation and potentially exacerbating morbidity and mortality in children living with HIV.
Complete Genome Sequence of
Nocardia
sp. Strain CS682, a Producer of Antibacterial Compound Nargenicin A1
Authors: Dhakal Dipesh , Rayamajhi Vijay , Nguyen Hue Thi , Poudel Purna Bahadur , Sohng Jae Kyung
Published: December 2019

Nocardia
sp. strain CS682 is a rare actinobacterium with a promising ability to produce secondary metabolites such as nargenicin A1 (an effective antibacterial compound) and IBR-3 (a UV-protectant molecule). Here, we report the complete genome sequence of
Nocardia
sp. CS682, obtained by PacBio sequencing as a single contig with 8,919,230 bp (GC content, 63.3%).
Complete Genome Sequence of the Ebosin-Producing Strain
Streptomyces
sp. 139
Authors: Ai Limei , Geng Mengxin , Ma Ming , Bai Liping
Published: December 2019

Members of the genus
Streptomyces
are known for their ability to produce compounds with various bioactivities and for their complex morphologies.
Streptomyces
sp. strain 139 is the producer strain of the exopolysaccharide (EPS) ebosin, which has remarkable
in vivo
antirheumatic arthritis activity. Here, we report its complete genome sequence, which will facilitate the study of the biosynthesis of ebosin.
Draft Genome Sequence of Enterobacter hormaechei ENT5, a Component of the Symbiotic Community of Tephritid Flies
Authors: Asimakis Elias , Doudoumis Vangelis , Gouvi Georgia , Tsiamis George
Published: December 2019

Enterobacterstrains are among the dominant symbiotic bacteria in the gastrointestinal tract of insects, with the ability to fulfill diverse roles. In this announcement, we describe the draft genome sequence ofEnterobacter hormaecheistrain ENT5, isolated from wild adultZeugodacus cucurbitaeflies.
Staphylococcus pseudintermediuscatheter-related bloodstream infection after exposure to domestic dogs and a cat
Authors: Diaz Mark Anthony , Gardner Lindsay B , Libertin Claudia R
Published: December 2019

We report a case of a catheter-related bloodstream infection due to oxacillin-susceptibleStaphylococcus pseudintermediusin a patient receiving haemodialysis who possibly acquired the organism from her pets. Because of persistent bacteremia and the organism’s ability to form biofilm, catheter removal and antimicrobial therapy were indicated to attain source control. Both clinical and microbiological cure were confirmed. Catheter care education should include information about pet exposure and the possibility of zoonotic infections.
FulminantSphingomonas paucimobiliskeratitis: case study and review of literature
Authors: Agarwal Rinky , Gagrani Meghal , Mahajan Asmita , Sharma Namrata
Published: December 2019

Sphingomonas paucimobilisis a low-virulence gram-negative bacillus known to cause various ocular infections such as endophthalmitis, panophthalmitis and keratitis that are usually associated with an underlying risk factor such as peri-partum or postpartum phase, cataract surgery, contact lens use, neurotrophic keratopathy or ocular trauma. We report a case of spontaneously occurring perforated corneal ulcer caused by the organism in a young man managed by penetrating keratoplasty. The course was followed by endophthalmitis with graft infection culminating in phthisis bulbi despite aggressive medical and surgical management. Along with reporting this case, we also present a review of literature on ocular infections caused by the same organism.
Measuring an individual researcher’s impact: new directions and challenges
Authors: Senior Morwenna , Fazel Seena
Published: December 2019

Metrics which quantify the impact of a scientist are increasingly incorporated into decisions about how to rate and fund individuals and institutions. Several commonly used metrics, based on journal impact factors and citation counts, have been criticised as they do not reliably predict real-world impact, are highly variable between fields and are vulnerable to gaming. Bibliometrics have been incorporated into systems of research assessment but these may create flawed incentives, failing to reward research that is validated, reproducible and with wider impacts. A recent proposal for a new standardised citation metric based on a composite indicator of 6 measures has led to an online database of 100 000 of the most highly cited scientists in all fields. In this perspective article, we provide an overview and evaluation of this new citation metric as it applies to mental health research. We provide a summary of its findings for psychiatry and psychology, including clustering in certain countries and institutions, and outline some implications for mental health research. We discuss strengths and limitations of this new metric, and how further refinements could align impact metrics more closely with wider goals of scientific research.
Bilateral lateral patellar luxation in a calf
Authors: Strous Emma , Willems Nicole , Tobón Restrepo Mauricio , Vos Peter , Meij Björn
Published: December 2019

This case report documents the surgical treatment of bilateral lateral patellar luxation in a calf and the outcome by clinical examination, radiography, CT and postmortem examination. A 21‐day‐old calf was referred because of severe hindlimb weakness. Orthopaedic examination and radiographs revealed a grade 3 bilateral lateral patellar luxation with normal stifle bone anatomy. Surgery consisted of lateral desmotomy with excision of proliferative capsular tissues and imbrication of the medial retinaculum and resulted in anatomic repositioning of the patella. Aftercare consisted of treatment with ampicillin and meloxicam, a modified Robert Jones bandage with a spica splint and physiotherapy. In between surgeries CT was performed. The lameness in both hindlimbs gradually improved over time and the calf developed a normal stance and gait. After euthanasia CT was repeated and pathology performed, showing normal articular cartilage of the stifle and correct location of the patellae without signs of inflammation.
Suspected anaphylaxis after intravenous administration of cefuroxime (Zinacef) in two dogs, with descriptions of arterial blood gas abnormalities over time
Authors: Leigh Hannah , Harðardottir Hulda , Schöffmann Gudrun , Panti Ambra
Published: December 2019

Two cases of suspected anaphylaxis occurred in the authors’ hospital within two weeks of each other. The first, a six‐year‐and‐four‐month‐old border collie, presented for thoracic wall resection. Once anaesthetised, 20 mg/kg of intravenous cefuroxime (Zinacef 75 mg/ml, GlaxoSmithKline UK) was administered slowly for prophylactic antibiosis. Ten minutes after administration was completed,desaturation occurred alongside tachycardia, hypotension and apnoea. Chest compliance was extremely poor, with minimal chest movement. Treatment included intermittent positive pressure ventilation, intravenous fluids, terbutaline, adrenaline and dexamethasone. The second case, a five‐year‐and‐eight‐month‐old Lhasa apso, presented for elective orthopaedic surgery. Intravenous cefuroxime (Zinacef 75 mg/ml) was again administered slowly for prophylactic antibiosis; however, it is uncertain whether the patient received the full dose of 20 mg/kg. Mid‐administration tachycardia, tachypnoea and hypotension occurred,alongside poor chest compliance. Cefuroxime administration was stopped, the fluid line disconnected and treatment with chlorphenamine given.
Photodetachment of the H– ion in a forced harmonic potential
Authors: Wang De-hua
Published: December 2019

The photodetachment of a H– ion in a forced harmonic potential driven by a general time-dependent oscillating electric field has been investigated in the semi-classical closed orbit theory for the first time. It is found that the driven electric field frequency can affect the photodetachment cross-section of this system greatly. If the frequency of the driving electric field is equal to the harmonic frequency, a resonance phenomenon occurs in the classical motion of the detached electron. The interference effect between the returning electron wave travelling along the closed orbit with the initial outgoing wave gets stronger, causing the photodetachment cross-section to oscillate in a complicated manner. When the frequency of the driving electric field is unequal to the harmonic frequency, the driving electric field can weaken or strengthen the oscillatory structure in the photodetachment cross-section. In addition, the strength and initial phase in the driving electric field can also influence the photodetachment dynamics of the system. Our work provides a new method for controlling the photodetachment of negative ions in a harmonic potential and may guide future experimental research for cavity dynamics or in the ion trap.
Rigid group actions on complex tori are projective (after Ekedahl)
Authors: Catanese Fabrizio , Demleitner Andreas
Published: December 2019

In this paper, we give a detailed proof of a result due to Torsten Ekedahl, describing complex tori admitting a rigid group action and showing explicitly their projectivity and their structure in terms of CM-fields. In the appendix, joint with Claudon, we show, using a method of Green-Voisin, that all group actions on complex tori deform to projective ones.
The finitary content of sunny nonexpansive retractions
Authors: Kohlenbach Ulrich , Sipoş Andrei
Published: December 2019

We use techniques of proof mining to extract a uniform rate of metastability (in the sense of Tao) for the strong convergence of approximants to fixed points of uniformly continuous pseudocontractive mappings in Banach spaces which are uniformly convex and uniformly smooth, i.e. a slightly restricted form of the classical result of Reich. This is made possible by the existence of a modulus of uniqueness specific to uniformly convex Banach spaces and by the arithmetization of the use of the limit superior. The metastable convergence can thus be proved in a system which has the same provably total functions as first-order arithmetic and therefore one may interpret the resulting proof in Gödel’s system [Formula: see text] of higher-type functionals. The witness so obtained is then majorized (in the sense of Howard) in order to produce the final bound, which is shown to be definable in the subsystem [Formula: see text]. This piece of information is further used to obtain rates of metastability to results which were previously only analyzed from the point of view of proof mining in the context of Hilbert spaces, i.e. the convergence of the iterative schemas of Halpern and Bruck.
Suppressive Effect of Huzhentongfeng on Experimental Gouty Arthritis: An In Vivo and In Vitro Study
Authors: Wu Zi-cong , Xue Qiang , Zhao Zhen-ling , Zhou Peng-jun , Zhou Qun , Zhang Zhen , Deng Jian-ping , Yang Ke , Fan Hua , Wang Yi-fei , Wang Zhi-ping
Published: December 2019

Background. Huzhentongfeng (HZTF) is an extract from four Chinese medical herbs for treating gout. This study aims to evaluate its antigout activity and preliminary explore its mechanism in vivo and in vitro. Methods. The rats were intragastrically administered with HZTF for 5 days and then injected 0.1 ml (10 mg) of MSU crystals to their joints for generating a gout model to analyze the paw volume and histopathology of joint synovial tissues of rats with different doses. We also investigated the antioxidant capacity of HZTF in vitro using indication including lipid peroxidation, DPPH·, and ABTS+ radical-scavenging capacity; besides, we used qRT-PCR to measure the effect of HZTF on interleukin (IL)-1β, caspase-1, NLRP3, and NQO1 expression in hydrogen peroxide-stimulated RAW264.7 macrophages and IL-1β, IL-6, and tumor necrosis factor (TNF)-α in MSU crystal-induced THP-1 monocytes. Confocal microscopy analysis was used to observe the dimerization of ASC adapter proteins. In addition, we also established quality standard of HZTF by using the high-performance liquid chromatography (HPLC) method. Results. HZTF could significantly suppress the paw swelling and neutrophil infiltration induced by MSU intra-articular injection in rats compared with the control group. HZTF also showed inhibition effects of inflammatory cytokines (IL-1β, IL-6, and TNF-α) secretion at 25.00 and 50.00 μg/ml in MSU-induced THP-1 cells but showed no effects of IL-1β, IL-6, and TNF-α mRNA expression in MSU-induced THP-1 cells. Furthermore, confocal microscopy analysis showed that HZTF could prevent the oligomerization of ASC. Moreover, HZTF also showed effects in cell-free and cell-base tests of antioxidant capacity. Conclusion. The results prove that HZTF possessed the potential preventive effect against gout arthritis, and the effect may be attributed to its preventing effect on neutrophil infiltration and proinflammatory cytokines secretion such as IL-1β, IL-6, and TNF-α which were caused by the activation of inflammasome.
Interdecadal Variability of Summer Precipitation Efficiency in East Asia
Authors: Wang Jian , Gui Shu , Ma Anqi , Yang Ruowen , Zhang Qi
Published: December 2019

Precipitation efficiency (PE) is a crucial physical quantity in convective processes, describing the efficiency of rainfall generation from cloud detrainment. Although the importance of PE in extreme precipitation events is widely accepted, the evolution of PE in the warming climate and the associated moisture processes in East Asia are still not well understood. To address these issues, the interdecadal variability of PE in East Asia during summer in 1979–2016 is investigated in this study. Two major modes of summertime precipitation efficiency are identified using Empirical Orthogonal Function (EOF) analysis. The leading EOF mode (EOF1) has a dipole pattern that reveals the variations of mean precipitation efficiency. The second EOF mode (EOF2) presents a quadrupole pattern that shows changes in the variability of precipitation efficiency. Both EOF modes exhibit significant interdecadal variability (IDV). The IDV of EOF1 is closely associated with the phase change of the Pacific decadal oscillation (PDO). The Pacific sea surface temperature anomalies associated with the PDO can excite wind anomalies that significantly modulate moisture transport and further alter the mean precipitation efficiency in East Asia. The IDV of EOF2 can be attributed to the interdecadal change of occurrence frequency of Eastern Pacific El Niño-Southern Oscillation (ENSO) events, which affect water vapor transport by inducing an East Asia-Pacific teleconnection-like wave train anomaly pattern. The IDV patterns of precipitation efficiency for both the mean value and variability will improve the ability to predict precipitation in East Asia.
Bioinformatic Profiling Identifies a Fatty Acid Metabolism-Related Gene Risk Signature for Malignancy, Prognosis, and Immune Phenotype of Glioma
Authors: Qi Ying , Chen Di , Lu Qiqi , Yao Yu , Ji Chunxia
Published: December 2019

Cancer cells commonly have metabolic abnormalities. Aside from altered glucose and amino acid metabolism, cancers cells often share the attribute of fatty acid metabolic alterations. However, fatty acid metabolism related-gene set has not been systematically investigated in gliomas. Here, we provide a bioinformatic profiling of the fatty acid catabolic metabolism-related gene risk signature for the malignancy, prognosis and immune phenotype of glioma. In this study, a cohort of 325 patients with whole genome RNA-seq expression data from the Chinese Glioma Genome Atlas (CGGA) dataset was used as training set, while another cohort of 667 patients from The Cancer Genome Atlas (TCGA) dataset was used as validating set. After confirmed that fatty acid catabolic metabolism-related gene set could distinguish clinicopathological features of gliomas, we used LASSO regression analysis to develop a fatty-acid metabolism-related gene risk signature for glioma. This 8-gene risk signature was found to be a good predictor of clinical and molecular features involved in the malignancy of gliomas. We also identified that this 8-gene risk signature had high prognostic values in patients with gliomas. Correlation analysis showed that our risk signature was closely associated with the immune cells involved in the microenvironment of glioma. Furthermore, the fatty acid catabolic metabolism-related gene risk signature was also found to be significantly correlated with immune checkpoint members B7-H3 and Tim-3. In summary, we have identified a fatty acid metabolism-related gene risk signature for malignancy, prognosis, and immune phenotype of glioma; and our study might contribute to better understanding of metabolic pathways and further developing of novel therapeutic approaches for gliomas.