bluuebunny/crossref_metadata_2025 huggingface dataset:
Streamline Modeling of Manifold Microchannels in Thin Film Evaporation
Authors: Mandel Raphael , Shooshtari Amir , Dessiatoun Serguei , Ohadi Michael
Published: December 2013

Manifold microchannels utilize a system of manifolds to divide long microchannels into an array of parallel ones, resulting in reduced flow length and more localized liquid feeding. Reducing flow length is desirable because it enables the simultaneous enhancement of heat transfer rate and reduction of pressure drop. Furthermore, localized feeding reduces potential for localized dryout, increasing the operational heat flux. Because of the failure of the available conventional heat transfer correlations to predict the thermal performance of manifold microchannels operating in two phase mode, a “streamline” model was created. The heat transfer surface area was divided into parallel, non-interacting streamlines, and the quality, void fraction, film thickness, heat transfer coefficient, heat flux, and pressure drop was calculated sequentially along the streamline. The mass flow rate through each streamline was adjusted in order to obtain the specified pressure drop, and the value of this pressure drop was adjusted in order to obtain the desired microchannel mass flux. Finally, the average wall heat transfer coefficient was calculated, and temperature profile in the fin was adjusted to correspond with the analytical 1-D temperature distribution of a thin fin with an average wall heat transfer coefficient and specified base superheat. The average wall heat transfer coefficients predicted by the model was then compared to the available experimental data with sufficiently good agreement with a wide variety of geometries and working fluids at low mass fluxes.
Thermally-Induced Dispersion of Coolant Mixtures Through Heated Layered Materials
Authors: Tilley B. S.
Published: December 2013

Although the experimental capability to design and fabricate specific microstructures in materials has advanced significantly in the past few decades, a description of their effective thermal behavior on the macroscale has not kept pace. The length scales of the fundamental processes (approximately 100 nm–10 micron, or microscale) are typically several orders of magnitude smaller than the scales dictated by a given application (1 mm–1 cm, or macroscale). We are interested in extending classical asymptotic approaches to allow for the spatial pattern wavenumber to vary on the macroscale variables and to find how changes in microstructure geometry affect macroscopic properties and transport. To this end, we consider here the thermal transport of a binary fluid (coolant) through nonuniformly spaced laminates, as a simple model for heat sinks in electronics. Power is continuously being generated by the laminates, and the local rates of heat transport depend on the composition of the binary mixture. However, segregation of the mixture can occur under favorable temperature gradients, which could potentially affect the local heat transfer from the laminate to the coolant. We derive sets of effective equations that describe the evolution of the temperature field, the local coolant composition, the fluid velocity and the pressure over the macroscale that are driven by the net effects of the microscale processes. The evolution of these quantities is driven by the local heat generation within the laminates, lamellar geometry gradients, the prescribed flow rate of coolant entering the system, along with the fundamental material properties of the laminates and the coolants. Microscale values of all of these quantities are known in terms of the solutions to these effective eqautions. We are especially interested in geometries in the laminate spacing which allow for better thermal transport by the coolant for a prescribed power distribution.
Computational Simulation of the Impact and Freezing of Micron-Size Water Droplets on Super-Hydrophobic Surfaces
Authors: Raessi Mehdi , Thiele Miranda , Amirzadeh Behrooz
Published: December 2013

We present a computational study on the dynamics and freezing of micron-size water droplets impinging onto super-hydrophobic surfaces, the temperatures of which are below the freezing point of water. Icing poses a great challenge for many industries. It is well known that increasing hydrophobicity can make a surface ice-phobic. Experiments show that millimeter size water drops landing on super-hydrophobic surfaces bounce off even when the surface temperature is well below the freezing point. However, it has been reported that the ice-phobicity feature of such surfaces can vanish due to frost formation on the surface, or when small micro-droplets begin to freeze and stick to the surface. Using an in-house, 3D, GPU-accelerated computational tool, we investigated the impact dynamics and freezing of a 40 μm water droplet impinging at 1.4 m/s onto two different super-hydrophobic surfaces chosen from [1]. The advancing and receding contact angles are 165° and 133°, respectively, on one surface, and 157° and 118°, respectively, on the other. The surface and initial droplet temperatures were varied from −25 to 25°C and from 0 to 25°C, respectively. On each surface a “transition” surface temperature was found, at which the drop behavior transitions from bouncing off the surface to sticking. The time between drop landing and bounce-off as well as the contact diameter between the stuck drop and the surface both increase with decreasing the surface temperature. The simulations also show that at some surface temperatures a thin ice layer forms during droplet spreading and then remelts as the droplet recoils.
Effect of Local Frost Characteristics on Thermal Performance of Fin Tube Heat Exchanger Under Frosting Condition
Authors: Kim Jeongkeun , Hwang Jieun , Cho Keumnam
Published: December 2013

The present study aimed to measure and predict frost characteristics and heat transfer rate of fin-tube specimen, and predicted them of fin-tube heat exchanger. Test conditions were air temperature from 0.5 to 7 °C, absolute humidity from 3.18 to 4.01 g/kgDA, air velocity from 0.5 to 2.5m/s, and coolant temperature from −15 to −5 °C. The coolant was ethylene-glycol aqueous solution with concentration of 50%. Correlation equations for the average frost thickness and frost surface temperature were proposed. The proposed correlation equation for the average frost thickness and average frost surface temperature agreed with the measured data within the maximum deviation of 20% and 15%. The average frost thickness in front and front mass were predicted and compared with the measured data. They agreed within ±14 and ±23%, respectively. The heat transfer rate was predicted and compared with the measured data. They agreed within ±13% when the total heat transfer rate was over 70W.
Effect of Electric Field on a 3D Rising Bubble in Viscous Fluids
Authors: Yang Qingzhen , Liu Yang , Li Ben Q. , Ding Yucheng
Published: December 2013

Understanding of a rising bubble in fluid with the presence of external fields is of fundamental importance in boiling heat transfer and gas-liquid flows. In this paper, a computational methodology is presented for a modeling study of hydrodynamic behavior of a bubble rising in fluid subject to an applied electric field. The computational model is developed by solving the Navier-Stokes equation coupled with the phase field model and electric field equations. The coupled model is capable of predicting the evolution of electric field, bubble motion and deformation and the medium fluid. Numerical simulations were conducted to study the combined effect of coupled electrical force, gravity, surface tension and viscous force on the deformation and motion of a bubble as it ascends through the liquid. The liquid and gas are considered as the dielectric fluids and both vertical and horizontal electric fields are studied. The in-house Fortran code was developed to enable the simulation, and numerical results are presented showing that the deformation and rising speed of the bubble are affected by the applied electric field in both magnitude and direction.
Analytical Modeling of a Bubble Column Dehumidifier
Authors: Tow Emily W. , Lienhard John H.
Published: December 2013

Bubble column dehumidifiers are a compact, inexpensive alternative to conventional fin-tube dehumidifiers for humidification-dehumidification (HDH) desalination, a technology that has promising applications in small-scale desalination and industrial water remediation. In this paper, algebraic equations for relevant mean heat and mass transfer driving forces are developed for improved modeling of bubble column dehumidifiers. Because mixing in the column ensures a uniform liquid temperature, the bubble column can be modeled as two single stream heat exchangers in contact with the column liquid: the seawater side, for which a log-mean temperature difference is appropriate, and the gas side, which has a varying heat capacity and mass exchange. Under typical conditions, a log-mean mass fraction difference is shown to drive latent heat transfer, and an expression for the mean temperature difference of the moist gas stream is presented. These expressions will facilitate modeling of bubble column heat and mass exchangers.
Heat Transfer Through Metal-Foam Heat Exchanger at Higher Temperature
Authors: Hafeez P. , Esmaeelpanah J. , Chandra S. , Mostaghimi J.
Published: December 2013

Open pore metal foams are lightweight and offer high strength, rigidity, and a large heat transfer area per volume. They make efficient heat exchangers because of high thermal conductivity and high permeability. These heat exchangers made of nickel foam are suitable for high temperature application. They can be manufactured by shaping the foam into any desired configuration and depositing metal skins on it using thermal spray deposition method. Combustion based heating system that burns natural gas is designed to understand the heat transfer through metal foam heat exchanger at higher temperature. A test rig has been fabricated to perform heat transfer experiments. The rig is capable of generating hot combustion gases through methane-oxygen premixed combustion chamber. The design of the rig allows exposure of the thermally sprayed nickel foam to hot gases and finally, cooling the metal foam by circulating air through it. The experiments were performed on metal foam and hollow channel to measure the heat transfer enhancement of the metal foam. The surface temperature measurements were done for different flow rates of cooling air. A significant decrease in surface temperature of metal foam was observed.
Study on Condensation Heat Transfer Characteristics of Nonazeotropic Binary Refrigerant Mixture R1234yf/R32 Inside Small-Scale Horizontal Smooth Tubes
Authors: Wang Linlin , Dang Chaobin , Hihara Eiji
Published: December 2013

In this study, condensation heat transfer characteristics of nonazeotropic mixtures R1234yf and R32 (mass fractions of 0.52:0.48 and 0.77:0.23, respectively) inside a horizontal smooth tube (inner diameter 2 mm) were experimentally investigated at mass fluxes ranging from 100 to 400 kg/m2 s and at a saturation temperature of 40 °C. A prediction model using a modified heat transfer correlation for pure refrigerant was constructed, the details of which are presented here. The heat transfer characteristics, especially the heat transfer deterioration caused by the mass transfer difference of the nonazeotropic refrigerant mixture, were evaluated by combining the correlations of heat transfer and mass transfer on both the vapor side and the liquid side. Through comparison with experimental data, the obtained prediction results were found to agree reasonably with the experimental condensation heat transfer coefficient of binary refrigerant mixtures using R1234yf and R32.
Comparison of Heat Transfer Characteristics of Water Impinging Flow With a Single Circular Nozzle and an Insert Type Swirling Nozzle
Authors: Kim Tae Hoon , Do Kyu Hyung , Oh Dong-Wook , Lee Jungho , Park Jang-Min
Published: December 2013

Conventional impinging jets enhance heat transfer but produce non-uniform radial distributions of the local and surface Nusselt numbers. In attempt to improve the radial uniformity of heat transfer, many researchers have introduced the concept of the swirling flow.

The swirling flow can be generated by strips or swirling generators. The swirling generator is a circular rod with helical blades. The swirling generator is inserted inside a tube. This swirling generator with helical blades can generate swirling flow at the outlet of the nozzle. First of all, flow visualization of swirling jet as varying swirling angles, the length of the swirl generators, and distance between nozzle exit and a swirl generator is investigated. Based on the flow visualization, it is found that the distance between nozzle exit and a swirl generator affects the performance of swirling jet. For heat transfer analysis, an induction heating method is used to heat a steel plate up to a certain level which is almost the same as temperature of steel in iron- and steelmaking processes. For obtaining temperature distribution on impinging surface, several thermocouples are inserted below 1mm from the surface of the sample. Based on temperature distributions on the surface of a sample, 2-D temperature contours are obtained according to time. Based on the contours, effect of distance from nozzle exit to a swirling generator on uniform cooling is investigated.
Numerical Simulation of Backward Film Cooling With Fan-Shaped Holes
Authors: Subbuswamy Ganesh , Li Xianchang , Gharat Kunal
Published: December 2013

The thermal efficiency of a gas turbine is largely dependent on the turbine inlet temperature (TIT). Modern gas turbines may operate at temperatures as high as 2000K, which is higher than the melting point of the material in use. Hence, thermal protection of gas turbine hot components is a big challenge. Film cooling is the most common cooling technique adopted in this application. In film cooling, coolant is injected at discrete locations along the metal surface, which forms a layer of cool air immediately over the hot surface, thus, protecting it from direct contact with hot mainstream air. The cooling is strong along the centerline of the hole in the downstream region and rapidly decreases over the span-wise direction. The distributed cooling can result in large thermal gradients, inducing thermal stresses in the material. The region with least cooling may lead to a cascade failure of the blade. Film cooling with backward injection holes has been proved to reduce this effect. In the current work, backward coolant injection scheme is explored under fan-shaped holes numerically. Fluent, a commercial CFD software, is used in the current work for numerical simulations. Effects of blowing ratio, injection angle, and turbulence are considered. Numerical results show that fan-shaped holes are better than simple cylindrical holes in terms of both cooling effectiveness and its uniformity. Numerical results are validated with experimental results. The image of temperature fields on cooling surface is captured with an Infrared camera.
Numerical Study of Aerodynamic Performance of Film Cooling With Backward Injection Holes
Authors: Subbuswamy Ganesh , Li Xianchang , Gharat Kunal
Published: December 2013

Film cooling has been successfully used in cooling gas turbine components that are exposed to very high temperature environments. One main disadvantage of using film cooling is the aerodynamic losses associated. To address to the needs of obtaining uniform cooling in the downstream regions, backward injection of coolant has proved to be effective. However, there is a need to understand the aerodynamic behaviors of jet and mainstream flows in order to design effective configurations with this scheme of injecting coolant. In this work, the underlying aerodynamic principles of backward injection are studied numerically. All simulations are conducted with Fluent, a commercial CFD software. Results show that the classical counter rotating vortex found in simple cylindrical holes are not seen in the case of backward injections. Backward injection results in reduced coolant requirements and elimination of complex hole designs to avoid jet lift-off.
Heat Transfer Enhancement for Turbine Blade Internal Cooling
Authors: Wright Lesley M. , Han Je-Chin
Published: December 2013

Gas turbines are used extensively for aircraft propulsion, land-based power generation, and industrial applications. The turbine inlet temperatures are far above the permissible metal temperatures. Therefore, there is a need to cool the blades for safe operation. Modern developments in turbine cooling technology play a critical role in increasing the thermal efficiency and power output of advanced gas turbine designs. Turbine blades and vanes are cooled internally and externally. This paper focuses on heat transfer augmentation of turbine blade internal cooling. Internal cooling is typically achieved by passing the cooling air through rib-enhanced serpentine passages inside the blades. Impinging jets, pin fins and dimples are also used for enhancing internal cooling heat transfer. In the past 10 years, there has been considerable progress in turbine blade internal cooling research and this paper is emphasized on reviewing selected publications to reflect recent developments in this area. In particular, this paper focuses on the newly developed design concepts as well as the combination of existing cooling techniques for turbine airfoil internal heat transfer augmentation. Rotation effects on the turbine blade leading-edge, triangular-shaped channel, mid-chord multi-pass channel and trailing-edge, wedge-shaped channel with coolant ejection are also considered.
Performance of Coaxial Ceiling-Mounted Personalized Ventilator for Comfort and Good Air Quality
Authors: Ghaddar Nesreen , Ghali Kamel , Makhoul Alain
Published: December 2013

The aim of this work is to study the performance of a novel ceiling mounted coaxial personalized ventilator that can be used as an add on to the conventional ceiling diffuser in providing the thermal comfort and air quality needs to occupants in office building. A detailed 3D CFD model is coupled to a bioheat model to improve prediction of the microenvironment conditions around the human and the associated local and overall thermal comfort. Extensive simulations were performed to assess the effect of nozzle supply temperature and flow rate on the performance of the cooling system and on occupant comfort. The localized air conditioning system reduced the energy consumption by up to 34% when compared with conventional mixing systems providing the same level of thermal comfort. The proposed system also achieved high air quality in the occupant breathing zone with 45% ventilation effectiveness at fresh airflow rate of 10 L/s/person and attained 2°C between the occupant’s comfortable microenvironment and the rest of the space. In addition, the canopy of the angled diffuser was effective in reducing the migration of particles from the macroclimate to the microclimate region and low intake fractions of 1.90×10−4 were achieved.
Analysis of Li-Ion Battery Characteristics and Thermal Behavior
Authors: Chatterjee Krishnashis , Majumdar Pradip , Schroeder David , Kilaparti S. Rao
Published: December 2013

Development of electric and hybrid electric vehicles is of great interest to the transportation industry due to increased demand and cost of imported fuel, uncertainty in the steady supply of oil, and increased standards for reduced emissions. Lithium-ion batteries are considered as one of the leading types for the battery systems to be employed in electric vehicles (EVs) or hybrid electric vehicles (HEVs). Using a regenerative braking system and storing it in battery stacks and using it later for propulsion and acceleration can improve the overall efficiency and reduction of fuel consumption.

The objective of this study is to evaluate experimentally the battery performance considering different discharge and charge rates, and investigate the thermal behavior and thermal management requirements of the batteries under a variety of environmental conditions. An experimental test facility has been developed to evaluate thermal performance during charging and discharging modes. Environmental temperatures were varied in environmental chamber to analyze their effects on the charging and discharging patterns of the battery by using the CADEX battery analyzer in order to find the temperature range for optimum battery performance. The batteries were monitored with thermal sensors and a thermal imaging camera while they were run through different load scenarios. In the present study, lithium-ion batteries have been tested and battery performance in terms of polarization curves and discharge capacity were measured using a computerized battery analyzer system for different discharge and charge rates, and over a range of ambient temperatures. Results indicate that at higher discharge and charge rates battery performance decreases due to increased polarization losses, which results in increased internal heat generation and temperature of the battery. Battery performance also depends strongly on the ambient temperature conditions.
Conjugated Heat Transfer in Heat Spreaders With Micro-Channels
Authors: Knupp Diego C. , Cotta Renato M. , Naveira Cotta Carolina P.
Published: December 2013

This work is aimed at the experimental verification of a recently proposed single domain formulation of conjugated conduction-convection heat transfer problems, which are often of relevance in thermal micro-systems analysis. The single domain formulation simultaneously models the heat transfer phenomena at both the fluid streams and the channels walls by making use of coefficients represented as space variable functions with abrupt transitions occurring at the fluid-wall interfaces. The Generalized Integral Transform Technique (GITT) is then employed in the hybrid numerical-analytical solution of the resulting convection-diffusion problem with variable coefficients. The considered experimental investigation involves the determination of the temperature distribution over a heat spreader made of a nanocomposite plate with a longitudinally molded single micro-channel that exchanges heat with the plate by flowing hot water at an adjustable mass flow rate. The infrared thermography technique is employed to analyze the response of the heat spreader surface, aiming at the analysis of micro-systems that provide a thermal response from either their normal operation or due to a promoted stimulus for characterization purposes.
A Numerical Study of a Single Unsteady Laminar Slot Jet in a Confined Structure
Authors: Ghaffari Omidreza , Dogruoz M. Baris , Arik Mehmet
Published: December 2013

With the inherit advantages of air cooling, jet impingement can produce a factor of two or higher heat transfer than conventional fan flow over bodies. Therefore, impinging jets can solve a number of electronics thermal issues. Those jets produce complex flow and thermal structures leading to non-uniform and non-monotonic profiles on target surfaces. A numerical study is performed to investigate the flow and heat transfer characteristics of an unsteady laminar impinging jet emanated from a single high-aspect ratio rectangular (slot) nozzle in a confined arrangement. The spacing between the target plate and the nozzle is such that the jet would still be in its potential core length as it was in a free axial jet. Following the initial transients, flow and heat transfer parameters still vary considerably in time that the instantaneous and time-averaged values of surface profiles are not identical. Instantaneous surface pressure distributions exhibit that the stagnation point translates periodically around the initial jet-symmetry line and the surface profiles demonstrate off-center (non-stagnation point) peaks.
Mating Induces Shrinking and Death in
Caenorhabditis
Mothers
Authors: Shi Cheng , Murphy Coleen T.
Published: December 2013

Battle of the Sexes

In many species, males compete with one another to propagate their own DNA, often to the detriment of females (see the Perspective by
Promislow and Kaeberlein
).
Shi and Murphy
(p.
536
, published online 19 December) discovered that mating in
Caenorhabditis
species causes mothers to shrink and die soon after they have ceased producing progeny. Males appear to hijack the longevity and stress resistance pathways normally employed by the mothers to slow reproduction and somatic aging in times of stress.

Maures
et al.

(p.
541
, published online 29 November) explored why the presence of abundant mating-competent males causes a decrease in the life span of nematodes of the opposite sex and found that a secreted substance, possibly a pheromone, reproduced the effect of the males when transferred in the culture medium. Detection of pheromones from a female fruit fly is enough to cause changes in metabolism, reduce resistance to starvation, and shorten the life span of male flies.

Gendron
et al.

(p.
544
, published online 29 November) report that the signals from the female appear to be recognized by sensory receptors on the legs of male flies.
Charge Order Driven by Fermi-Arc Instability in Bi
2
Sr

2−
x

La

x

CuO
6+δ
Authors: Comin R. , Frano A. , Yee M. M. , Yoshida Y. , Eisaki H. , Schierle E. , Weschke E. , Sutarto R. , He F. , Soumyanarayanan A. , He Yang , Le Tacon M. , Elfimov I. S. , Hoffman Jennifer E. , Sawatzky G. A. , Keimer B. , Damascelli A.
Published: December 2013

The understanding of the origin of superconductivity in cuprates has been hindered by the apparent diversity of intertwining electronic orders in these materials. We combined resonant x-ray scattering (REXS), scanning-tunneling microscopy (STM), and angle-resolved photoemission spectroscopy (ARPES) to observe a charge order that appears consistently in surface and bulk, and in momentum and real space within one cuprate family, Bi

 
2

Sr

 

2
−
x

La

 
x

CuO

 

6
+
δ

. The observed wave vectors rule out simple antinodal nesting in the single-particle limit but match well with a phenomenological model of a many-body instability of the Fermi arcs. Combined with earlier observations of electronic order in other cuprate families, these findings suggest the existence of a generic charge-ordered state in underdoped cuprates and uncover its intimate connection to the pseudogap regime.
IFI16 DNA Sensor Is Required for Death of Lymphoid CD4 T Cells Abortively Infected with HIV
Authors: Monroe Kathryn M. , Yang Zhiyuan , Johnson Jeffrey R. , Geng Xin , Doitsh Gilad , Krogan Nevan J. , Greene Warner C.
Published: December 2013

The progressive depletion of quiescent “bystander” CD4 T cells, which are nonpermissive to HIV infection, is a principal driver of the acquired immunodeficiency syndrome (AIDS). These cells undergo abortive infection characterized by the cytosolic accumulation of incomplete HIV reverse transcripts. These viral DNAs are sensed by an unidentified host sensor that triggers an innate immune response, leading to caspase-1 activation and pyroptosis. Using unbiased proteomic and targeted biochemical approaches, as well as two independent methods of lentiviral short hairpin RNA–mediated gene knockdown in primary CD4 T cells, we identify interferon-γ–inducible protein 16 (IFI16) as a host DNA sensor required for CD4 T cell death due to abortive HIV infection. These findings provide insights into a key host pathway that plays a central role in CD4 T cell depletion during disease progression to AIDS.
Order of Magnitude Smaller Limit on the Electric Dipole Moment of the Electron
Authors:   The ACME Collaboration, Baron J. , Campbell W. C. , DeMille D. , Doyle J. M. , Gabrielse G. , Gurevich Y. V. , Hess P. W. , Hutzler N. R. , Kirilov E. , Kozyryev I. , O’Leary B. R. , Panda C. D. , Parsons M. F. , Petrik E. S. , Spaun B. , Vutha A. C. , West A. D.
Published: December 2013

Stubbornly Spherical

The shape of the electron's charge distribution reflects the degree to which switching the direction of time impacts the basic ingredients of the universe. The Standard Model (SM) of particle physics predicts a very slight asphericity of the charge distribution, whereas SM extensions such as supersymmetry posit bigger and potentially measurable, but still tiny, deviations from a perfect sphere. Polar molecules have been identified as ideal settings for measuring this asymmetry, which should be reflected in a finite electric dipole moment (EDM) because of the extremely large effective electric fields that act on an electron inside such molecules. Using electron spin precession in the molecule ThO,

Baron
et al.

(p.
269
, published online 19 December; see the cover; see the Perspective by

Brown

) measured the EDM of the electron as consistent with zero. This excludes some of the extensions to the SM and sets a bound to the search for a nonzero EDM in other facilities, such as the Large Hadron Collider.
Complete Genome Sequences of Two Waterfowl-Origin Tembusu Virus Strains Isolated in Shandong Province, China
Authors: Chen Hao , Liu Xin , Tang Yi , Zhang Ying , Ti Jinfeng , Gao Xuhui , Diao Youxiang
Published: December 2013

Here, we report the complete genome sequences of two tembusu virus strains, ZC-1 and LQ-1, isolated from ducks and geese, respectively, in 2012. Phylogenetic analysis showed that the nucleotide and amino acid sequences of the two strains are closely related to those of the TMUV isolates around Shandong province. The full-length genome sequences of two waterfowl-origin TMUVs provided herein will help to understand the molecular epidemiology of tembusu virus in China, which deserves further investigation.
Complete Genome of Bacillus subtilis Myophage CampHawk
Authors: Ritz Morgan P. , Perl Abbey L. , Colquhoun Jennifer M. , Chamakura Karthik R. , Kuty Everett Gabriel F.
Published: December 2013

The study of bacteriophages infecting the model organism
Bacillus subtilis
has provided an abundance of general knowledge and a platform for advances in biotechnology. Here, we announce the annotated genome of CampHawk, a
B. subtilis
phage. CampHawk was found to be an SPO1-like phage with similar gene content and arrangement.
Draft Genome Sequences of Human Pathogenic Fungus
Geomyces pannorum Sensu Lato
and Bat White Nose Syndrome Pathogen
Geomyces
(
Pseudogymnoascus
)
destructans
Authors: Chibucos Marcus C. , Crabtree Jonathan , Nagaraj Sushma , Chaturvedi Sudha , Chaturvedi Vishnu
Published: December 2013

We report the draft genome sequences of
Geomyces pannorum sensu lato
and
Geomyces (Pseudogymnoascus) destructans
.
G. pannorum
has a larger proteome than
G. destructans
, containing more proteins with ascribed enzymatic functions. This dichotomy in the genomes of related psychrophilic fungi is a valuable target for defining their distinct saprobic and pathogenic attributes.
Complete Genome Sequence of
Exiguobacterium
sp. Strain MH3, Isolated from Rhizosphere of
Lemna minor
Authors: Tang Jie , Zhang Ying , Meng Hao , Xue Zhiquan , Ma Jiong
Published: December 2013

We report the complete genome sequence of
Exiguobacterium
sp. strain MH3, isolated from the rhizosphere of duckweed. The genome assembly is 3.16 Mb, with a G+C content of 47.24%, and it may provide useful information about plant-microbe interactions and the genetic basis for the tolerance of the strain to various environmental stresses.
Genome Sequence of Strain MOLA814, a Proteorhodopsin-Containing Representative of the
Betaproteobacteria
Common in the Ocean
Authors: Courties Alicia , Riedel Thomas , Jarek Michael , Intertaglia Laurent , Lebaron Philippe , Suzuki Marcelino T.
Published: December 2013

Strain MOLA814 is a marine betaproteobacterium that was isolated from seawater in the Beaufort Sea. Here, we present its genome sequence and annotation. Genome analysis revealed the presence of a proteorhodopsin-encoding sequence together with its retinal-producing pathway, indicating that this strain might generate energy by using light.
Complete Genome Sequence of a Multidrug-Resistant Salmonella enterica Serovar Typhimurium var. 5− Strain Isolated from Chicken Breast
Authors: Hoffmann Maria , Muruvanda Tim , Allard Marc W. , Korlach Jonas , Roberts Richard J. , Timme Ruth , Payne Justin , McDermott Patrick F. , Evans Peter , Meng Jianghong , Brown Eric W. , Zhao Shaohua
Published: December 2013

Salmonella enterica
subsp.
enterica
serovar Typhimurium is a leading cause of salmonellosis. Here, we report a closed genome sequence, including sequences of 3 plasmids, of
Salmonella
serovar Typhimurium var. 5− CFSAN001921 (National Antimicrobial Resistance Monitoring System [NARMS] strain ID N30688), which was isolated from chicken breast meat and shows resistance to 10 different antimicrobials. Whole-genome and plasmid sequence analyses of this isolate will help enhance our understanding of this pathogenic multidrug-resistant serovar.
Draft Genome Sequences of Two Strains of Propionibacterium acnes Isolated from Radical Prostatectomy Specimens
Authors: Mak Tim N. , Sfanos Karen S. , Brüggemann Holger
Published: December 2013

Propionibacterium acnes
is a Gram-positive bacterium that is closely associated with various parts of the human body, in particular with sebaceous follicles of the skin. It has also been frequently isolated from diseased human prostates. Here, we report draft genome sequences of two
P. acnes
strains, P6 and PA2, isolated from radical prostatectomy specimens.
Complete Genome Sequence of a Novel Pigeon Torque Teno Virus in China
Authors: Zhang Zhicheng , Zhuang Linlin , Dai Wei , Mao Huihua , Dai Dingzhen
Published: December 2013

Torque teno virus is a nonenveloped single-stranded DNA virus infecting humans and nonprimate species. We report the complete genome sequence of a pigeon torque teno virus isolated from pigeons in Jiangsu Province, China, in 2012. This genome sequence will be useful for viral diagnostics and disease control.
Draft Genome Sequence of
Pseudomonas
Strain P818, Isolated from Glyphosate-Polluted Soil
Authors: Cao Gaoyi , Liu Yunjun , Liu Guiming , Wang Jianhua , Wang Guoying
Published: December 2013

Pseudomonas
strain P818 was isolated from glyphosate-polluted soil in China. This bacterium presents a capacity for high glyphosate tolerance. We present the draft genome sequence of the strain
Pseudomonas
P818. The genes involved in the glyphosate tolerance were identified. This genomic information will facilitate the study of glyphosate tolerance mechanisms.
Towards evidence-based dosing regimens in children on the basis of population pharmacokinetic pharmacodynamic modelling
Authors: Admiraal Rick , van Kesteren Charlotte , Boelens Jaap Jan , Bredius Robbert G M , Tibboel Dick , Knibbe Catherijne A J
Published: December 2013

When growing up, the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of drugs change, which may alter the effect of drugs. To ensure optimal drug efficacy and safety in paediatric care, PK and PD relationships of drugs need to be explored in children. This article presents an outline on performing a population PK/PD study and translating these results into rational dosing regimens, with the development and prospective evaluation of PK/PD derived evidence-based dosing regimen being discussed. Examples on amikacin, morphine and busulfan are provided, showing how PK(/PD) modelling not only led to optimization and individualization in paediatric clinical care for the specific drugs but also to insight in maturation of organ systems involved. It is shown that the latter results can subsequently be used as a basis for dosing of other drugs eliminated through the same pathway. Ultimately, these efforts should lead to predictable drug efficacy and safety across all age groups.
Splenectomy during pregnancy: treatment of refractory immune thrombocytopenic purpura
Authors: Mahey Reeta , Kaur Simran Deep , Chumber Sunil , Kriplani Alka , Bhatla Neerja
Published: December 2013

Immune thrombocytopenic purpura (ITP) complicates 1–2/10 000 pregnancies and accounts for 5% of cases of pregnancy-associated thrombocytopenia. Corticosteroids and intravenous immunoglobulin remain the first-line therapy in pregnancy, and a majority of pregnant women respond to this conventional therapy. Other cytotoxic and immunosuppressive agents used for treatment in non-pregnant patients, for example, danazol, cyclophosphamide, vinca alkaloids and azathioprine, are potential teratogens and cannot be administered during pregnancy. For pregnant women with ITP who fail to respond to medical management and are at a significant risk of haemorrhage due to thrombocytopenia, splenectomy may be considered as an option. We report two cases of splenectomy during pregnancy for refractory ITP. In one patient, it was carried out at 24 weeks, and in the second patient it was carried out during the caesarean section. Splenectomy as a second-line option in cases of refractory severe ITP in pregnancy is discussed.
Bus stops and pedestrian–motor vehicle collisions in Lima, Peru: a matched case–control study
Authors: Quistberg D Alex , Koepsell Thomas D , Johnston Brian D , Boyle Linda Ng , Miranda J Jaime , Ebel Beth E
Published: December 2013

Objective

To evaluate the relationship between bus stop characteristics and pedestrian–motor vehicle collisions.

Methods

This was a matched case–control study where the units of study were pedestrian crossings in Lima, Peru. We performed a random sample of 11 police commissaries in Lima, Peru. Data collection occurred from February 2011 to September 2011. A total of 97 intersection cases representing 1134 collisions and 40 mid-block cases representing 469 collisions that occurred between October 2010 and January 2011, and their matched controls, were included. The main exposures assessed were presence of a bus stop and specific bus stop characteristics. The main outcome measure was occurrence of a pedestrian–motor vehicle collision.

Results

Intersections with bus stops were three times more likely to have a pedestrian–vehicle collision (OR 3.28, 95% CI 1.53 to 7.03), relative to intersections without bus stops. Formal and informal bus stops were associated with higher odds of a collision at intersections (OR 6.23, 95% CI 1.76 to 22.0 and OR 2.98, 1.37 to 6.49). At mid-block sites, bus stops on a bus-dedicated transit lane were also associated with collision risk (OR 2.36, 95% CI 1.02 to 5.42). All bus stops were located prior to the intersection, contrary to practices in most high-income countries.

Conclusions

In urban Lima, the presence of a bus stop was associated with a threefold increase in risk of a pedestrian collision. The highly competitive environment among bus companies may provide an economic incentive for risky practices, such as dropping off passengers in the middle of traffic and jockeying for position with other buses. Bus stop placement should be considered to improve pedestrian safety.
Improved tissue sections for medical liver biopsies: a comparison of 16 vs 18 g biopsy needles using digital pathology
Authors: Palmer Timothy , Georgiades Izabela , Treanor Darren , Wright Alexander , Shah Mushtaq , Khosla Randeep , Wyatt Judith I
Published: December 2013

Background

Most medical liver biopsies in the UK are now taken in radiology departments using 18 g biopsy needles. Subjectively, the resulting biopsies are narrow and fragile.

Aim

To compare the quality of liver biopsy tissue sections obtained from 16 and 18 g biopsy needles.

Method

Fifty consecutive routine medical liver biopsies obtained with 16 and 18 g needles, processed identically in the same laboratory, were measured using digital pathology software. We recorded their fragmentation, length, width, area and number of portal tracts.

Results

Biopsies obtained with 16 g needles more often resulted in an intact core in tissue sections than those with 18 g needles (71% vs 24%, p<0.001) and were significantly wider (average width of tissue 0.88 vs 0.53 mm, p<0.001). The average total area of tissue per pass was 11.38 mm2compared with 8.34 mm2(p<0.001). The number of complete portal tracts per length of biopsy was very variable, but double for 16 vs 18 g biopsies. Routinely taking two passes with the 18 g needle compensated for the reduced area, but the resulting liver in tissue sections was fragmented and distorted.

Conclusions

Our results support the routine use of 16 g rather than 18 g biopsy needles for routine ultrasound-guided medical liver biopsies. A second pass should be considered if the first biopsy core is short, especially for investigation of disease stage.
Foliar colleters inMacrocarpaea obtusifolia(Gentianaceae): anatomy, ontogeny, and secretion
Authors: Dalvi Valdnéa Casagrande , Cardinelli Lucas Siqueira , Meira Renata Maria Strozi Alves , Azevedo Aristéa Alves
Published: December 2013

Colleters are secretory structures located in reproductive and (or) vegetative organs of many eudicots. In Gentianaceae Juss., the presence of foliar colleters has been neglected, and anatomical and histochemical studies are scarce. The objectives of this study were to investigate the anatomy, ontogeny, and chemical nature of the secretion found in Macrocarpaea obtusifolia (Griseb.) Gilg colleters to establish a relationship between their structure and function and check whether these structures are similar to those described for other genera of the Gentianaceae and other families of the Gentianales. Samples of leaves at different developmental stages were collected and processed for anatomical and histochemical analysis using light microscopy and scanning electron microscopy. Colleters in M. obtusifolia have a protodermal origin, are of standard type, and are not vascularized. Young colleters are translucent and produce an abundant amount of sticky secretion. Later, they turn yellowish with a blackened region at the apex of the head, and the secretion, composed of polysaccharides and proteins, becomes less abundant and brownish. During senescence, the process begins with complete degradation and cell collapse of the secretory portion. The colleters of the standard type in M. obtusifolia have been observed for the first time in the Gentianaceae and represent additional evidence that reinforces how common this type of colleter is in the Gentianales. Such results provide new information on the anatomy, ontogeny, histochemistry, and colleter types of Gentianaceae.
Germanium-centered free radicals studied by muon spin spectroscopy
Authors: West Robert , Samedov Kerim , Mitra Amitabha , Percival Paul W. , Brodovitch Jean-Claude , Langille Graeme , McCollum Brett M. , Iwamoto Takeaki , Ishida Shintaro , Jones Cameron , Li Jiaye
Published: December 2013

Transverse-field muon spin rotation (TF-μSR) spectra have been recorded for free radicals formed by positive muon irradiation of nine different divalent germanium compounds. Muon-electron hyperfine coupling constants (Aμ) were determined from the spectra and compared with values predicted from density functional theory molecular orbital (DFT-MO) calculations on the muoniated radicals formed by muonium addition to the germanium atom. The muon hyperfine constants for germylenes containing N–Ge bonds are generally quite large, from 593 to 942 MHz, indicating strong interaction between the muon and the unpaired electron in these radicals. The radical derived from one of the germylenes exhibited a significantly lower muon hyperfine constant, suggesting that in this case the muoniated germyl radical undergoes a coupling reaction to form a digermanyl radical, which is what is detected by μSR.
Do chemically contaminated river estuaries in Puget Sound (Washington, USA) affect the survival rate of hatchery-reared Chinook salmon?
Authors: Meador James P.
Published: December 2013

This study examined the rate of survival for hatchery-reared, ocean-type juvenile Chinook salmon (Oncorhynchus tshawytscha) to the adult life stage in relation to contamination status for estuaries where they temporarily reside. The hypothesis tested here is that juvenile Chinook from Puget Sound (Washington, USA) area hatcheries exhibit differential survival as categorized by the state of contamination in their respective natal estuaries. Data were examined from 20 hatcheries that released fish to 14 local estuaries in the Greater Puget Sound area over 37 years (1972–2008). A parallel analysis was also conducted for coho salmon (Oncorhynchus kisutch) outmigrating from many of the same hatcheries. For all years combined, juvenile Chinook transiting contaminated estuaries exhibited an overall rate of survival that was 45% lower than that for Chinook moving through uncontaminated estuaries, which was confirmed when tested year by year. The results for coho originating from the same hatcheries and sharing a similar marine distribution indicated no substantial differences among estuaries. These observations have important implications for wild juvenile Chinook that spend more time in the estuary compared with hatchery-reared fish.
Isolation, screening, characterization, and selection of superior rhizobacterial strains as bioinoculants for seedling emergence and growth promotion of Mandarin orange (Citrus reticulataBlanco)
Authors: Thokchom Elizabeth , Kalita Mohan Chandra , Talukdar Narayan Chandra
Published: December 2013

Mandarin orange (MO) is an important fruit crop of tropical and subtropical regions of the world. A total of 217 morphologically distinct rhizobacteria from MO orchards in 3 states of northeastern India were isolated and analyzed for 4 plant-growth-promoting (PGP) attributes: nitrogen fixation, production of indole acetic acid like substances, solubilization of phosphate, and ability to antagonize pathogenic fungi. Isolates were ranked based on in-vitro-assayed PGP attributes, and 10 superior isolates were selected to test their effect on seedling emergence and seedling growth in a completely randomized pot experiment. These 10 isolates increased seedling emergence over a noninoculated control within 45 days after sowing. Five isolates, namely RCE1, RCE2, RCE3, RCE5, and RCE7, significantly increased shoot length, shoot dry biomass, and root dry biomass of 120-day-old seedlings over the noninoculated control. The beneficial effects of 4 selected strains, namely Enterobacter hormaechei RCE-1, Enterobacter asburiae RCE-2, Enterobacter ludwigii RCE-5, and Klebsiella pneumoniae RCE-7, on growth of the seedlings were visible up to 1 year after their transfer to 8 kg capacity pots. These strains were superior both in terms of in-vitro-assayed PGP attributes and of their beneficial effect in low phosphorus soil and, thus, may be promising bioinoculants for promoting early emergence and growth of MO seedlings.
Enhancement of optical properties of poly (9,9′-di-n-octylfluorenyl-2,7-diyl) in conjugated polymer/TiO2 nanocomposites
Authors: Al-Asbahi Bandar Ali , Jumali Mohammad Hafizuddin Haji
Published: December 2013

The influence of colloidal TiO2 nanoparticle contents on the optical properties of poly (9,9′-di-n-octylfluorenyl-2,7-diyl) conjugated polymer (PFO) has been investigated. The solution blending method was used to prepare homogenous PFO/TiO2 nanocomposite. The nanocomposite films were prepared on glass substrates using the spin-coating technique. The films were divided into two groups, the first was left to dry at room temperature while the second was heat-treated at 120 °C for 1 h. Absorption and emission spectra showed that the PFO existed in α- and β-phases morphology having monomeric, excimeric, and double excimeric states. In addition, both spectra revealed that TiO2 contents and heat treatment temperature extended the conjugation length of PFO. Finally, emission spectra for both cases exhibited decreasing in the line width of zero-phonon emission spectra and increasing in the vibronic splitting energy, upon increment of the TiO2, led to a significant increase in π-electron delocalization and lower degree in chain disorder.