bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refrigeration Process With High Speed Technology
Authors: Kuosa Maunu , Backman Jari , Talonpoika Timo , Sallinen Petri , Larjola Jaakko , Honkatukia Juha 
Published: December 2014

The aim of this study was to make a computer program that simulates a standard refrigeration process, and a process provided with a bubble intercooler. A further object of the study was to establish the suitability of a turbocompressor for small refrigeration plants.
Firstly the fundamentals of refrigeration machines and industrial refrigeration systems are discussed. An iteration procedure of steady state refrigeration process calculation is introduced. Fluid properties are calculated with the program units created for the modelling of an ORC power plant. Specific input files were made for 6 process fluids R134a, R123, isopentane, isobutane, toluene and ammonia. The compressor program is linked to the refrigeration process simulation program in order to model single stage and two stage radial compressors. The Turbo Pascal program made for microcomputers is modular, which makes it possible to develop and test the program unit by unit. The maximum deviations of fluid properties from those in tables was found to be less than 1 per cent.
To simulate tailor-made refrigeration plants, a simple model is required. On nominal loads the program estimates an optimum intermediate pressure for the bubble process and optimum rotational speed for the radial compressor(s). The lowering of the rotational speed by an inverter gives high COP-values on partial loads of the plant. Based on the example calculation, a two stage turbocompressor calculated with isopentane as the working fluid, a cooling capacity of 1200 W seems to be feasible.
Experimental and Numerical Investigations of Film-Cooling Effects on the Aerodynamic Performance of Transonic Turbine Blades
Authors: Urban Martin F. , Hermeler Juergen , Hosenfeld Hans-Georg 
Published: December 2014

This paper presents results of experimental as well as numerical investigations of the aerodynamic performance of film-cooled transonic turbine blades. Taking into consideration to non-dimensional similarity, the experiments were performed on a cascade test rig using superheated steam as fluid. The investigated blading corresponds to a typical high pressure turbine vane used in the high subsonic regime.
In order to determine the effect of the blown-out cooling fluid on the aerodynamic performance of the cascade, the measurements were performed over a wide range of realistic exit Mach numbers, mass flow rate ratios, coolant injection locations and main-to-coolant flow density ratios.
The paper presents the results of the experimental investigation in the form of outlet angles and loss terms, and compares and discusses these for a number of variations. It was found that below a critical mass flow ratio, the kinetic loss coefficient varies only little with flow rate whereas above this critical flow ratio, the loss coefficient increases rapidly.
A comparison of the different injection locations shows that the suction side is very sensitive with regard to main flow disturbances while injection on the pressure side and the trailing edge only has a small effect of the loss terms. Consideration of different coolant-to-mainstream density ratios clarifies that the influence of this parameter on the loss terms can be neglected.
The paper also addresses a simple numerical code which is based on the „TOTLOS“ model of Hansel and adapted to the above-mentioned problem, and compares and discusses the results of the experimental and numerical investigations.
Exogenous contrast agents for thermoacoustic imaging: An investigation into the underlying sources of contrast
Authors: Ogunlade Olumide , Beard Paul 
Published: December 2014

Purpose:Thermoacoustic imaging at microwave excitation frequencies is limited by the low differential contrast exhibited by high water content tissues. To overcome this, exogenous thermoacoustic contrast agents based on gadolinium compounds, iron oxide, and single wall carbon nanotubes have previously been suggested and investigated. However, these previous studies did not fully characterize the electric, magnetic, and thermodynamic properties of these agents thus precluding identification of the underlying sources of contrast. To address this, measurements of the complex permittivity, complex permeability, DC conductivity, and Grüneisen parameter have been made. These measurements allowed the origins of the contrast provided by each substance to be identified.Methods:The electric and magnetic properties of the contrast agents were characterized at 3 GHz using two rectangular waveguide cavities. The DC conductivity was measured separately using a conductivity meter. Thermoacoustic signals were then acquired and compared to those generated in water. Finally, 3D electromagnetic simulations were used to decouple the different contributions to the absorbed power density.Results:It was found that the gadolinium compounds provided appreciable electric contrast but not originating from the gadolinium itself. The contrast was either due to dissociation of the gadolinium salt which increased ionic conductivity or its nondissociated polar fraction which increased dielectric polarization loss or a combination of both. In addition, very high concentrations were required to achieve appreciable contrast, to the extent that the Grüneisen parameter increased significantly and became a source of contrast. Iron oxide particles were found to produce low but measurable dielectric contrast due to dielectric polarization loss, but this is attributed to the coating of the particles not the iron oxide. Single wall carbon nanotubes did not provide measurable contrast of any type.Conclusions:It is concluded that gadolinium based contrast agents, iron oxide particles, and single walled carbon nanotubes have little intrinsic merit as thermoacoustic contrast agents. Simple electrolytes such as saline which yield high contrast based on ionic conductivity provide much higher dielectric contrast per unit solute concentration and are likely to be significantly more effective as contrast agents.
A Novel Device to Preserve Physical Activities of Daily Living in Healthy Older People
Authors: Haslinger Wolfram , Müller Lisa , Sarabon Nejc , Raschner Christian , Kern Helmut , Löfler Stefan 
Published: December 2014

Objective:To determine the effectiveness of exercise in improving sensorimotor function and functional performance, crucial parts of activities of daily living in healthy older adults.Design:RCT.Setting:Laboratory.Participants:39 subjects (M = 71.8 years, range: 61–89 years).Intervention:Task-oriented visual feedback balance training.Primary outcome measure:Timed Up & Go (TUG).Secondary outcome measures:Chair stand test (CST), self-paced walk test, maximum isometric torque, quiet stand posturography, and dynamic balance (DB).Results:Postintervention comparison of the treatment group (TG) and control group (CG) showed better TUG (p < .01), CST (p < .001), and DB (p < .025) for the TG. Pre–post intervention comparison of the TG showed better clinically-relevant outcomes in TUG (p < .001), CST (p < .001), and DB (p < .001).Conclusion:Active driven visual feedback balance training is effective in improving functional performance and dynamic balance in older adults.
Doripenem MICs and
ompK36
Porin Genotypes of Sequence Type 258, KPC-Producing Klebsiella pneumoniae May Predict Responses to Carbapenem-Colistin Combination Therapy among Patients with Bacteremia
Authors: Shields Ryan K. , Nguyen M. Hong , Potoski Brian A. , Press Ellen G. , Chen Liang , Kreiswirth Barry N. , Clarke Lloyd G. , Eschenauer Gregory A. , Clancy Cornelius J. 
Published: December 2014

ABSTRACT

Treatment failures of a carbapenem-colistin regimen among patients with bacteremia due to sequence type 258 (ST258), KPC-2-producing
Klebsiella pneumoniae
were significantly more likely if both agents were inactive
in vitro
, as defined by a colistin MIC of >2 μg/ml and the presence of either a major
ompK36
porin mutation (guanine and alanine insertions at amino acids 134 and 135 [ins aa 134–135 GD], IS
5
promoter insertion [
P
= 0.007]) or a doripenem MIC of >8 μg/ml (
P
= 0.01). Major
ompK36
mutations among KPC-
K. pneumoniae
strains are important determinants of carbapenem-colistin responses
in vitro
and
in vivo
.
Fluoroquinolone Resistance Does Not Impose a Cost on the Fitness of Clostridium difficile In Vitro
Authors: Wasels François , Kuehne Sarah A. , Cartman Stephen T. , Spigaglia Patrizia , Barbanti Fabrizio , Minton Nigel P. , Mastrantonio Paola 
Published: December 2014

ABSTRACT

Point mutations conferring resistance to fluoroquinolones were introduced in the
gyr
genes of the reference strain
Clostridium difficile
630. Only mutants with the substitution Thr-82→Ile in GyrA, which characterizes the hypervirulent epidemic clone III/027/NAP1, were resistant to all fluoroquinolones tested. The absence of a fitness cost
in vitro
for the most frequent mutations detected in resistant clinical isolates suggests that resistance will be maintained even in the absence of antibiotic pressure.
Targeting Mycobacterium tuberculosis Topoisomerase I by Small-Molecule Inhibitors
Authors: Godbole Adwait Anand , Ahmed Wareed , Bhat Rajeshwari Subray , Bradley Erin K. , Ekins Sean , Nagaraja Valakunja 
Published: December 2014

ABSTRACT

We describe inhibition of
Mycobacterium tuberculosis
topoisomerase I (MttopoI), an essential mycobacterial enzyme, by two related compounds, imipramine and norclomipramine, of which imipramine is clinically used as an antidepressant. These molecules showed growth inhibition of both
Mycobacterium smegmatis
and
M. tuberculosis
cells. The mechanism of action of these two molecules was investigated by analyzing the individual steps of the topoisomerase I (topoI) reaction cycle. The compounds stimulated cleavage, thereby perturbing the cleavage-religation equilibrium. Consequently, these molecules inhibited the growth of the cells overexpressing topoI at a low MIC. Docking of the molecules on the MttopoI model suggested that they bind near the metal binding site of the enzyme. The DNA relaxation activity of the metal binding mutants harboring mutations in the DxDxE motif was differentially affected by the molecules, suggesting that the metal coordinating residues contribute to the interaction of the enzyme with the drug. Taken together, the results highlight the potential of these small molecules, which poison the
M. tuberculosis
and
M. smegmatis
topoisomerase I, as leads for the development of improved molecules to combat mycobacterial infections. Moreover, targeting metal coordination in topoisomerases might be a general strategy to develop new lead molecules.
In Vitro
Activity and Resistance Profile of Dasabuvir, a Nonnucleoside Hepatitis C Virus Polymerase Inhibitor
Authors: Kati Warren , Koev Gennadiy , Irvin Michelle , Beyer Jill , Liu Yaya , Krishnan Preethi , Reisch Thomas , Mondal Rubina , Wagner Rolf , Molla Akhteruzzaman , Maring Clarence , Collins Christine 
Published: December 2014

ABSTRACT

Dasabuvir (ABT-333) is a nonnucleoside inhibitor of the RNA-dependent RNA polymerase encoded by the hepatitis C virus (HCV) NS5B gene. Dasabuvir inhibited recombinant NS5B polymerases derived from HCV genotype 1a and 1b clinical isolates, with 50% inhibitory concentration (IC
50
) values between 2.2 and 10.7 nM, and was at least 7,000-fold selective for the inhibition of HCV genotype 1 polymerases over human/mammalian polymerases. In the HCV subgenomic replicon system, dasabuvir inhibited genotype 1a (strain H77) and 1b (strain Con1) replicons with 50% effective concentration (EC
50
) values of 7.7 and 1.8 nM, respectively, with a 13-fold decrease in inhibitory activity in the presence of 40% human plasma. This level of activity was retained against a panel of chimeric subgenomic replicons that contained HCV NS5B genes from 22 genotype 1 clinical isolates from treatment-naive patients, with EC
50
s ranging between 0.15 and 8.57 nM. Maintenance of replicon-containing cells in medium containing dasabuvir at concentrations 10-fold or 100-fold greater than the EC
50
resulted in selection of resistant replicon clones. Sequencing of the NS5B coding regions from these clones revealed the presence of variants, including C316Y, M414T, Y448C, Y448H, and S556G, that are consistent with binding to the palm I site of HCV polymerase. Consequently, dasabuvir retained full activity against replicons known to confer resistance to other polymerase inhibitors, including the S282T variant in the nucleoside binding site and the M423T, P495A, P495S, and V499A single variants in the thumb domain. The use of dasabuvir in combination with inhibitors targeting HCV NS3/NS4A protease (ABT-450 with ritonavir) and NS5A (ombitasvir) is in development for the treatment of HCV genotype 1 infections.
Activity of Eravacycline against Enterobacteriaceae and Acinetobacter baumannii, Including Multidrug-Resistant Isolates, from New York City
Authors: Abdallah Marie , Olafisoye Olawole , Cortes Christopher , Urban Carl , Landman David , Quale John 
Published: December 2014

ABSTRACT

Eravacycline demonstrated
in vitro
activity against a contemporary collection of more than 4,000 Gram-negative pathogens from New York City hospitals, with MIC
50
/MIC
90
values, respectively, for
Escherichia coli
of 0.12/0.5 μg/ml,
Klebsiella pneumoniae
of 0.25/1 μg/ml,
Enterobacter aerogenes
of 0.25/1 μg/ml,
Enterobacter cloacae
0.5/1 μg/ml, and
Acinetobacter baumannii
of 0.5/1 μg/ml. Activity was retained against multidrug-resistant isolates, including those expressing KPC and OXA carbapenemases. For
A. baumannii
, eravacycline MICs correlated with increased expression of the
adeB
gene.
A Cronobacter turicensis O1 Antigen-Specific Monoclonal Antibody Inhibits Bacterial Motility and Entry into Epithelial Cells
Authors: Schauer Kristina , Lehner Angelika , Dietrich Richard , Kleinsteuber Ina , Canals Rocío , Zurfluh Katrin , Weiner Kerstin , Märtlbauer Erwin 
Published: December 2014

ABSTRACT

Cronobacter turicensis
is an opportunistic foodborne pathogen that can cause a rare but sometimes lethal infection in neonates. Little is known about the virulence mechanisms and intracellular lifestyle of this pathogen. In this study, we developed an IgG monoclonal antibody (MAb; MAb 2G4) that specifically recognizes the O1 antigen of
C. turicensis
cells. The antilipopolysaccharide antibody bound predominantly monovalently to the O antigen and reduced bacterial growth without causing cell agglutination. Furthermore, binding of the antibody to the O1 antigen of
C. turicensis
cells caused a significant reduction of the membrane potential which is required to energize flagellar rotation, accompanied by a decreased flagellum-based motility. These results indicate that binding of IgG to the O antigen of
C. turicensis
causes a direct antimicrobial effect. In addition, this feature of the antibody enabled new insight into the pathogenicity of
C. turicensis
. In a tissue culture infection model, pretreatment of
C. turicensis
with MAb 2G4 showed no difference in adhesion to human epithelial cells, whereas invasion of bacteria into Caco-2 cells was significantly inhibited.
Protective and Pathological Functions of CD8+T Cells in Leishmania braziliensis Infection
Authors: Cardoso Thiago Marconi , Machado Álvaro , Costa Diego Luiz , Carvalho Lucas P. , Queiroz Adriano , Machado Paulo , Scott Phillip , Carvalho Edgar M. , Bacellar Olívia 
Published: December 2014

ABSTRACTCutaneous leishmaniasis (CL) caused byLeishmania braziliensisis characterized by a strong Th1 response that leads to skin lesion development. In areas whereL. braziliensistransmission is endemic, up to 15% of healthy subjects have tested positive for delayed-type hypersensitivity to soluble leishmania antigen (SLA) and are considered to have subclinical (SC) infection. SC subjects produce less gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) than do CL patients, but they are able to control the infection. The aim of this study was to characterized the role of CD8+T cells in SC infection and in CL. Peripheral blood mononuclear cells (PBMC) were stimulated with SLA to determine the frequencies of CD4+IFN-γ+and CD8+IFN-γ+T cells. Monocytes from PBMC were infected withL. braziliensisand cocultured with CD8+T cells, and the frequencies of infected monocytes and levels of cytotoxicity markers, target cell apoptosis, and granzyme B were determined. The frequency of CD8+IFN-γ+cells after SLA stimulation was higher for SC individuals than for CL patients. The frequency of infected monocytes in SC cells was lower than that in CL cells. CL CD8+T cells induced more apoptosis of infected monocytes than did SC CD8+T cells. Granzyme B production in CD8+T cells was higher in CL than in SC cells. While the use of a granzyme B inhibitor decreased the number of apoptotic cells in the CL group, the use of z-VAD-FMK had no effect on the frequency of these cells. These results suggest that CL CD8+T cells are more cytotoxic and may be involved in pathology.
Divergent Targets of Aspergillus fumigatus AcuK and AcuM Transcription Factors during Growth
In Vitro
versus Invasive Disease
Authors: Pongpom Monsicha , Liu Hong , Xu Wenjie , Snarr Brendan D. , Sheppard Donald C. , Mitchell Aaron P. , Filler Scott G. 
Published: December 2014

ABSTRACT

In
Aspergillus nidulans
, the AcuK and AcuM transcription factors form a complex that regulates gluconeogenesis. In
Aspergillus fumigatus
, AcuM governs gluconeogenesis and iron acquisition
in vitro
and virulence in immunosuppressed mice. However, the function of AcuK was previously unknown. Through
in vitro
studies, we found that
A. fumigatus
Δ
acuK
single and Δ
acuK
Δ
acuM
double mutants had impaired gluconeogenesis and iron acquisition, similar to the Δ
acuM
mutant. Also, the Δ
acuK
, Δ
acuM
, and Δ
acuK
Δ
acuM
mutants had similar virulence defects in mice. However, the Δ
acuK
mutant had a milder defect in extracellular siderophore activity and induction of epithelial cell damage
in vitro
than did the Δ
acuM
mutant. Moreover, overexpression of
acuM
in the Δ
acuK
mutant altered expression of 3 genes and partially restored growth under iron-limited conditions, suggesting that AcuM can govern some genes independently of AcuK. Although the Δ
acuK
and Δ
acuM
mutants had very similar transcriptional profiles
in vitro
, their transcriptional profiles during murine pulmonary infection differed both from their
in vitro
profiles and from each other. While AcuK and AcuM governed the expression of only a few iron-responsive genes
in vivo
, they influenced the expression of other virulence-related genes, such as
hexA
and
dvrA
. Therefore, in
A. fumigatus
, while AcuK and AcuM likely function as part of the same complex, they can also function independently of each other. Furthermore, AcuK and AcuM have different target genes
in vivo
than
in vitro
, suggesting that
in vivo
infection stimulates unique transcriptional regulatory pathways in
A. fumigatus
.
Pathogenic Leptospira Species Acquire Factor H and Vitronectin via the Surface Protein LcpA
Authors: da Silva Ludmila Bezerra , Miragaia Lidia dos Santos , Breda Leandro Carvalho Dantas , Abe Cecilia Mari , Schmidt Mariana Costa Braga , Moro Ana Maria , Monaris Denize , Conde Jonas Nascimento , Józsi Mihály , Isaac Lourdes , Abreu Patrícia Antônia Estima , Barbosa Angela Silva 
Published: December 2014

ABSTRACT

Upon infection, pathogenic
Leptospira
species bind several complement regulators in order to overcome host innate immunity. We previously characterized a 20-kDa leptospiral surface protein which interacts with C4b binding protein (C4BP):
l
eptospiral
c
omplement regulator-acquiring
p
rotein A (LcpA). Here we show that LcpA also interacts with human factor H (FH), which remains functionally active once bound to the protein. Antibodies directed against short consensus repeat 20 (SCR20) inhibited binding of FH to LcpA by approximately 90%, thus confirming that this particular domain is involved in the interaction. We have also shown for the first time that leptospires bind human vitronectin and that the interaction is mediated by LcpA. Coincubation with heparin blocked LcpA-vitronectin interaction in a dose-dependent manner, strongly suggesting that binding may occur through the heparin binding domains of vitronectin. LcpA also bound to the terminal pathway component C9 and inhibited Zn
2+
-induced polymerization and membrane attack complex (MAC) formation. Competitive binding assays indicated that LcpA interacts with C4BP, FH, and vitronectin through distinct sites. Taken together, our findings indicate that LcpA may play a role in leptospiral immune evasion.
A Novel DNA-Binding Protein Plays an Important Role in Helicobacter pylori Stress Tolerance and Survival in the Host
Authors: Wang Ge , Maier Robert J. 
Published: December 2014

ABSTRACT

The gastric pathogen
Helicobacter pylori
must combat chronic acid and oxidative stress. It does so via many mechanisms, including macromolecule repair and gene regulation. Mitomycin C-sensitive clones from a transposon mutagenesis library were screened. One sensitive strain contained the insertion element at the locus of
hp119
, a hypothetical gene. No homologous gene exists in any (non-
H. pylori
) organism. Nevertheless, the predicted protein has some features characteristic of histone-like proteins, and we showed that purified HP119 protein is a DNA-binding protein. A Δ
hp119
strain was markedly more sensitive (viability loss) to acid or to air exposure, and these phenotypes were restored to wild-type (WT) attributes upon complementation of the mutant with the wild-type version of
hp119
at a separate chromosomal locus. The mutant strain was approximately10-fold more sensitive to macrophage-mediated killing than the parent or the complemented strain. Of 12 mice inoculated with the wild type, all contained
H. pylori
, whereas 5 of 12 mice contained the mutant strain; the mean colonization numbers were 158-fold less for the mutant strain. A proteomic (two-dimensional PAGE with mass spectrometric analysis) comparison between the Δ
hp119
mutant and the WT strain under oxidative stress conditions revealed a number of important antioxidant protein differences; SodB, Tpx, TrxR, and NapA, as well as the peptidoglycan deacetylase PgdA, were significantly less expressed in the Δ
hp119
mutant than in the WT strain. This study identified HP119 as a putative histone-like DNA-binding protein and showed that it plays an important role in
Helicobacter pylori
stress tolerance and survival in the host.
ASAP: An Automatic Algorithm Selection Approach for Planning
Authors: Vallati Mauro , Chrpa Lukáš , Kitchin Diane 
Published: December 2014

Despite the advances made in the last decade in automated planning, no planner outperforms all the others in every known benchmark domain. This observation motivates the idea of selecting different planning algorithms for different domains. Moreover, the planners' performances are affected by the structure of the search space, which depends on the encoding of the considered domain. In many domains, the performance of a planner can be improved by exploiting additional knowledge, for instance, in the form of macro-operators or entanglements. In this paper we propose ASAP, an automatic Algorithm Selection Approach for Planning that: (i) for a given domain initially learns additional knowledge, in the form of macro-operators and entanglements, which is used for creating different encodings of the given planning domain and problems, and (ii) explores the 2 dimensional space of available algorithms, defined as encodings–planners couples, and then (iii) selects the most promising algorithm for optimising either the runtimes or the quality of the solution plans.