bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vibration Baseline, a Useful Concept for Condition Monitoring of Rotating Equipment
Authors: Gorter J. , Klijn A. J. 
Published: April 2015

The condition of rotating equipment can be assessed using vibration measuring techniques. A number of these techniques including signal processing and analysis methods will be discussed briefly.
Finally experiences on gas turbines and centrifugal compressors, operating in the Dutch gas transmission system, will be used to define a useful vibration baseline for condition monitoring, maintenance purposes and availability.
Application of a Vehicular Designed, Heavy Duty Gas Turbine Engine to a Military Generator Set
Authors: Laux Samuel C. , Ware Robert N. 
Published: April 2015

The Patriot Air Defense Missile System (formerly SAM-D) is being deployed in Europe. The powerplant supplying electricity to the radar set and to the engagement control station is DOD Model D-424A, powered by the Allison Model GT-404 industrial gas turbine (IGT) engine. Designed as a vehicular engine, the application in a generator set is an interesting one, utilizing many of the following features originally intended to enhance the performance of trucks and buses:
• Dual, rotating disk regenerators dramatically improve fuel consumption by transferring heat energy from the exhaust gas stream to compressor discharge.
• Power transfer, intended to provide part load fuel economy in vehicles, is modified to furnish free-shaft start-fixed shaft run in generator sets.
• Free-shaft starts allow successful operation down to −50°F without auxiliary heaters.
The resultant gas turbine engine driven generator set — 150 kW, transportable, skid mounted, alternating current 400 Hz, tactical — has met the military requirements for performance and reliability.
Coal-Fueled Turbines: Deposition Research
Authors: Carpenter L. K. , Crouse F. W. , Halow J. S. 
Published: April 2015

The U.S. Department of Energy, Office of Fossil Energy, through its Morgantown Energy Technology Center, has initiated a program for the application of less expensive fuels for use in gas turbines; the overall objective is to develop an environmentally sound integrated direct-fired, coal fueled gas turbine system which will produce cost-competitive energy. The fuel is coal and may be in several forms which include a micronized powder, a slurry (with water, methanol, etc.), or a minimally cleaned, coal-derived gas.
The application of coal fuels to gas turbines raises a number of technical questions, a principal one being the development of deposits within the turbine. Several programs have been initiated, that are aimed at development of an understanding of turbine deposition from coal fuels. Some of DOE’s research activities which are discussed within this paper include efforts in: (a) nozzle cascade tests utilizing advanced and conventional blade cooling to minimize deposition, (b) bench-scale combustion/deposition tests, (c) laboratory research aimed at defining particle stickiness, and (d) theoretical efforts to model gas stream nucleation of particles and the resulting deposition on blades cooled to various temperatures.
An Investigation of the Response of Temperature Sensing Probes to an Unsteady Flow Field
Authors: Agnew B. , Elder R. L. , Terrel M. 
Published: April 2015

The response of temperature measuring devices to pulsating flow fields has been a source of concern to compressor designers. A conventional temperature sensing device is known to respond to the highly energetic wake flow leaving a rotor and due to the long thermal time constant of the probe a temperature lying between the hot wake temperature and the relatively cooler main stream temperature tends to be indicated. This indicated temperature can be in serious error if included in a calculation to define the energy flux.
This work is concerned with a theoretical and experimental examination of temperature sensor response to an unsteady pulsating flow typical of that occuring in a compressor.
Flow Measurements in Two Cambered Vane Diffusers With Different Passage Widths
Authors: Stein W. , Rautenberg M. 
Published: April 2015

To investigate the influence of the vaneless space between impeller exit and the diffuser vanes, datailed flow measurements in two diffusers with the same vane geometry but different passage width are compared.
The three-dimensional character of the flow changes between impeller exit and the entry to the two dimensional vanes depending on the shape of the shroud. After initial measurements with a constant area vaneless space, the width of the vaned diffuser was later on reduced by 10%. The compressor maps show an increase in overall pressure rise and efficiency with the width reduction.
To get further details of the flow field, measurements of the static pressure distribution at hub and shroud have been performed at several operation points for both diffusers. At the same points the flow angle and total pressure distribution between hub and shroud upstream and downstream of the vanes have been measured with probes. The maximum efficiency of the narrow diffuser is nearly 2% higher than for the wide diffuser. The measurements give further details to explain this improvements.
Effect of Alternate Fuels on the Performance of the Garrett T76 Turboprop
Authors: Davis F. G. , Ball I. C. , Graham M. L. , White C. D. 
Published: April 2015

A Garrett T76 turboprop was used as the test vehicle to evaluate the effects of varying fuel properties on engine hot-section performance and durability. This program was funded by the Naval Air Propulsion Center (NAPC) as part of their program to determine fuel effects on Navy fleet engines. The test fuels were supplied by NAPC and the fuel properties covered a range of values that are being considered for possible future fuel specification modification.
Testing was performed on a full-scale combustion rig at conditions duplicating actual engine operation and on a T76 engine. Rig tests were used to determine turbine inlet temperature quality, lean stability, and ground ignition and altitude relight limits. Engine tests evaluated combustor liner temperatures, gaseous emissions, smoke, carbon deposition and fuel thermal stability. Following testing, regression analyses were performed to quantify the effects of specific fuel property values on combustor performance and durability.
Leisure-Time Physical Activity Does not Attenuate the Association Between Occupational Sedentary Behavior and Obesity: Results From Alberta’s Tomorrow Project
Authors: Nicholas Joshua A. , Siou Geraldine Lo , Lynch Brigid M. , Robson Paula J. , Friedenreich Christine M. , Csizmadi Ilona 
Published: April 2015

Background:Sedentary behavior has been proposed as a risk factor for obesity that is distinct from physical inactivity. This study aimed to examine the association between occupational sedentary behavior and obesity, and to determine if this association is independent of leisure-time physical activity (LTPA).Methods:Fully employed participants enrolled between 2001 and 2008 to Alberta’s Tomorrow Project, a prospective cohort study in Alberta, Canada, were studied (n = 12,409). Associations between occupational sedentary behavior and waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI) were examined using multiple binary and multinomial logistic regressions.Results:In men, a positive association was observed between daily occupational sedentary hours and WC, WHR, BMI, and with high risk profiles that incorporated both BMI and WC (P < .01). Controlling for vigorous-intensity LTPA in all models strengthened associations between sedentary behavior and measures of obesity. In contrast, inverse associations were observed for occupational sedentary hours and WHR for women (P < .05).Conclusions:In fully employed men, occupational sedentary behavior was positively associated with obesity risk that was not attenuated by physical activity. In women, an increase in obesity risk was not observed with sedentary behavior. Gender differences in the health effects of sedentary behavior require further study.
Candida albicans Cek1 Mitogen-Activated Protein Kinase Signaling Enhances Fungicidal Activity of Salivary Histatin 5
Authors: Li Rui , Puri Sumant , Tati Swetha , Cullen Paul J. , Edgerton Mira 
Published: April 2015

ABSTRACT

Candida albicans
is a major etiological organism for oropharyngeal candidiasis (OPC), while salivary histatin 5 (Hst 5) is a human fungicidal protein that protects the oral cavity from OPC.
C. albicans
senses its environment by mitogen-activated protein kinase (MAPK) activation that can also modulate the activity of some antifungal drugs, including Hst 5. We found that phosphorylation of the MAPK Cek1, induced either by
N
-acetylglucosamine (GlcNAc) or serum, or its constitutive activation by deletion of its phosphatase Cpp1 elevated the susceptibility of
C. albicans
cells to Hst 5. Cek1 phosphorylation but not hyphal formation was needed for increased Hst 5 sensitivity. Interference with the Cek1 pathway by deletion of its head sensor proteins, Msb2 and Sho1, or by addition of secreted aspartyl protease (SAP) cleavage inhibitors, such as pepstatin A, reduced Hst 5 susceptibility under Cek1-inducing conditions. Changes in fungal cell surface glycostructures also modulated Hst 5 sensitivity, and Cek1-inducing conditions resulted in a higher uptake rate of Hst 5. These results show that there is a consistent relationship between activation of Cek1 MAPK and increased Hst 5 susceptibility in
C. albicans
.
Berberine Blocks the Relapse of Clostridium difficile Infection in C57BL/6 Mice after Standard Vancomycin Treatment
Authors: Lv Zhi , Peng Guoli , Liu Weihua , Xu Hufeng , Su JianRong 
Published: April 2015

ABSTRACT

Vancomycin is a preferred antibiotic for treating
Clostridium difficile
infection (CDI) and has been associated with a rate of recurrence of CDI of as high as 20% in treated patients. Recent studies have suggested that berberine, an alternative medical therapy for gastroenteritis and diarrhea, exhibits several beneficial effects, including induction of anti-inflammatory responses and restoration of the intestinal barrier function. This study investigated the therapeutic effects of berberine on preventing CDI relapse and restoring the gut microbiota in a mouse model. Berberine was administered through gavage to C57BL/6 mice with established CDI-induced intestinal injury and colitis. The disease activity index (DAI), mean relative weight, histopathology scores, and levels of toxins A and B in fecal samples were measured. An Illumina sequencing-based analysis of 16S rRNA genes was used to determine the overall structural change in the microbiota in the mouse ileocecum. Berberine administration significantly promoted the restoration of the intestinal microbiota by inhibiting the expansion of members of the family
Enterobacteriaceae
and counteracting the side effects of vancomycin treatment. Therapy consisting of vancomycin and berberine combined prevented weight loss, improved the DAI and the histopathology scores, and effectively decreased the mortality rate. Berberine prevented CDIs from relapsing and significantly improved survival in the mouse model of CDI. Our data indicate that a combination of berberine and vancomycin is more effective than vancomycin alone for treating CDI. One of the possible mechanisms by which berberine prevents a CDI relapse is through modulation of the gut microbiota. Although this conclusion was generated in the case of the mouse model, use of the combination of vancomycin and berberine and represent a novel therapeutic approach targeting CDI.
Bistable Expression of CsgD in Salmonella enterica Serovar Typhimurium Connects Virulence to Persistence
Authors: MacKenzie Keith D. , Wang Yejun , Shivak Dylan J. , Wong Cynthia S. , Hoffman Leia J. L. , Lam Shirley , Kröger Carsten , Cameron Andrew D. S. , Townsend Hugh G. G. , Köster Wolfgang , White Aaron P. 
Published: April 2015

ABSTRACT

Pathogenic bacteria often need to survive in the host and the environment, and it is not well understood how cells transition between these equally challenging situations. For the human and animal pathogen
Salmonella enterica
serovar Typhimurium, biofilm formation is correlated with persistence outside a host, but the connection to virulence is unknown. In this study, we analyzed multicellular-aggregate and planktonic-cell subpopulations that coexist when
S
. Typhimurium is grown under biofilm-inducing conditions. These cell types arise due to bistable expression of CsgD, the central biofilm regulator. Despite being exposed to the same stresses, the two cell subpopulations had 1,856 genes that were differentially expressed, as determined by transcriptome sequencing (RNA-seq). Aggregated cells displayed the characteristic gene expression of biofilms, whereas planktonic cells had enhanced expression of numerous virulence genes. Increased type three secretion synthesis in planktonic cells correlated with enhanced invasion of a human intestinal cell line and significantly increased virulence in mice compared to the aggregates. However, when the same groups of cells were exposed to desiccation, the aggregates survived better, and the competitive advantage of planktonic cells was lost. We hypothesize that CsgD-based differentiation is a form of bet hedging, with single cells primed for host cell invasion and aggregated cells adapted for persistence in the environment. This allows
S
. Typhimurium to spread the risks of transmission and ensures a smooth transition between the host and the environment.
In Vitro
Anti-Plasmodium falciparum Properties of the Full Set of Human Secreted Phospholipases A
2
Authors: Guillaume Carole , Payré Christine , Jemel Ikram , Jeammet Louise , Bezzine Sofiane , Naika Gajendra S. , Bollinger James , Grellier Philippe , Gelb Michael H. , Schrével Joseph , Lambeau Gérard , Deregnaucourt Christiane 
Published: April 2015

ABSTRACT

We have previously shown that secreted phospholipases A
2
(sPLA
2
s) from animal venoms inhibit the
in vitro
development of
Plasmodium falciparum
, the agent of malaria. In addition, the inflammatory-type human group IIA (hGIIA) sPLA
2
circulates at high levels in the serum of malaria patients. However, the role of the different human sPLA
2
s in host defense against
P. falciparum
has not been investigated. We show here that 4 out of 10 human sPLA
2
s, namely, hGX, hGIIF, hGIII, and hGV, exhibit potent
in vitro
anti-
Plasmodium
properties with half-maximal inhibitory concentrations (IC
50
s) of 2.9 ± 2.4, 10.7 ± 2.1, 16.5 ± 9.7, and 94.2 ± 41.9 nM, respectively. Other human sPLA2s, including hGIIA, are inactive. The inhibition is dependent on sPLA
2
catalytic activity and primarily due to hydrolysis of plasma lipoproteins from the parasite culture. Accordingly, purified lipoproteins that have been prehydrolyzed by hGX, hGIIF, hGIII, and hGV are more toxic to
P. falciparum
than native lipoproteins. However, the total enzymatic activities of human sPLA
2
s on purified lipoproteins or plasma did not reflect their inhibitory activities on
P. falciparum
. For instance, hGIIF is 9-fold more toxic than hGV but releases a lower quantity of nonesterified fatty acids (NEFAs). Lipidomic analyses of released NEFAs from lipoproteins demonstrate that sPLA
2
s with anti-
Plasmodium
properties are those that release polyunsaturated fatty acids (PUFAs), with hGIIF being the most selective enzyme. NEFAs purified from lipoproteins hydrolyzed by hGIIF were more potent at inhibiting
P. falciparum
than those from hGV, and PUFA-enriched liposomes hydrolyzed by sPLA
2
s were highly toxic, demonstrating the critical role of PUFAs. The selectivity of sPLA
2
s toward low- and high-density (LDL and HDL, respectively) lipoproteins and their ability to directly attack parasitized erythrocytes further explain their anti-
Plasmodium
activity. Together, our findings indicate that 4 human sPLA
2
s are active against
P. falciparum
in vitro
and pave the way to future investigations on their
in vivo
contribution in malaria pathophysiology.
Increased Ferroportin-1 Expression and Rapid Splenic Iron Loss Occur with Anemia Caused by Salmonella enterica Serovar Typhimurium Infection in Mice
Authors: Brown Diane E. , Nick Heidi J. , McCoy Melissa W. , Moreland Sarah M. , Stepanek Aaron M. , Benik Ross , O'Connell Karyn E. , Pilonieta Maria C. , Nagy Toni A. , Detweiler Corrella S. 
Published: April 2015

ABSTRACTThe Gram-negative intracellular bacteriumSalmonella entericaserovar Typhimurium causes persistent systemic inflammatory disease in immunocompetent mice. Following oral inoculation withS. Typhimurium, mice develop a hematopathological syndrome akin to typhoid fever with splenomegaly, microcytic anemia, extramedullary erythropoiesis, and increased hemophagocytic macrophages in the bone marrow, liver, and spleen. Additionally, there is marked loss of iron from the spleen, an unanticipated result, given the iron sequestration reported in anemia of inflammatory disease. To establish why tissue iron does not accumulate, we evaluated multiple measures of pathology for 4 weeks following oral infection in mice. We demonstrate a quantitative decrease in splenic iron following infection despite increased numbers of splenic phagocytes. Infected mice have increased duodenal expression of the iron exporter ferroportin-1, consistent with increased uptake of dietary iron. Liver and splenic macrophages also express high levels of ferroportin-1. These observations indicate that splenic and hepatic macrophages export iron duringS. Typhimurium infection, in contrast to macrophage iron sequestration observed in anemia of inflammatory disease. Tissue macrophage export of iron occurs concurrent with high serum concentrations of interferon gamma (IFN-γ) and interleukin 12 (IL-12). In individual mice, high concentrations of both proinflammatory (tumor necrosis factor alpha [TNF-α]) and anti-inflammatory (IL-10) cytokines in serum correlate with increased tissue bacterial loads throughout 4 weeks of infection. Thesein vivoobservations are consistent with previous cell culture studies and suggest that the relocation of iron from tissue macrophages during infection may contribute to anemia and also to host survival of acuteS. Typhimurium infection.
Phosphorylation Events in the Multiple Gene Regulator of Group A Streptococcus Significantly Influence Global Gene Expression and Virulence
Authors: Sanson Misu , Makthal Nishanth , Gavagan Maire , Cantu Concepcion , Olsen Randall J. , Musser James M. , Kumaraswami Muthiah 
Published: April 2015

ABSTRACT

Whole-genome sequencing analysis of ∼800 strains of group A
Streptococcus
(GAS) found that the gene encoding the
m
ultiple virulence
g
ene regulator of G
A
S (
mga
) is highly polymorphic in serotype M59 strains but not in strains of other serotypes. To help understand the molecular mechanism of gene regulation by Mga and its contribution to GAS pathogenesis in serotype M59 GAS, we constructed an isogenic
mga
mutant strain. Transcriptome studies indicated a significant regulatory influence of Mga and altered metabolic capabilities conferred by Mga-regulated genes. We assessed the phosphorylation status of Mga in GAS cell lysates with Phos-tag gels. The results revealed that Mga is phosphorylated at histidines
in vivo
. Using phosphomimetic and nonphosphomimetic substitutions at conserved phosphoenolpyruvate:carbohydrate phosphotransferase regulation domain (PRD) histidines of Mga, we demonstrated that phosphorylation-mimicking aspartate replacements at H207 and H273 of PRD-1 and at H327 of PRD-2 are inhibitory to Mga-dependent gene expression. Conversely, non-phosphorylation-mimicking alanine substitutions at H273 and H327 relieved inhibition, and the mutant strains exhibited a wild-type phenotype. The opposing regulatory profiles observed for phosphorylation- and non-phosphorylation-mimicking substitutions at H273 extended to global gene regulation by Mga. Consistent with these observations, the H273D mutant strain attenuated GAS virulence, whereas the H273A strain exhibited a wild-type virulence phenotype in a mouse model of necrotizing fasciitis. Together, our results demonstrate phosphoregulation of Mga and its direct link to virulence in M59 GAS strains. These data also lay a foundation toward understanding how naturally occurring gain-of-function variations in
mga
, such as H201R, may confer an advantage to the pathogen and contribute to M59 GAS pathogenesis.
Parity-Dependent Recognition of DBL1X-3X Suggests an Important Role of the VAR2CSA High-Affinity CSA-Binding Region in the Development of the Humoral Response against Placental Malaria
Authors: Dechavanne Sébastien , Srivastava Anand , Gangnard Stéphane , Nunes-Silva Sofia , Dechavanne Célia , Fievet Nadine , Deloron Philippe , Chêne Arnaud , Gamain Benoît 
Published: April 2015

ABSTRACT

Plasmodium falciparum
multidomain protein VAR2CSA stands today as the leading vaccine candidate against pregnancy-associated malaria (PAM). Most of the studies aiming to decrypt how naturally acquired immunity develops have assessed the immune recognition of individual VAR2CSA Duffy-binding-like (DBL) domains, thus overlooking the presence of conformational epitopes resulting from the overall folding of the full-length protein. In order to characterize the development of humoral immunity toward VAR2CSA, we made use of a large cohort of 293 Senegalese pregnant women to assess the level of recognition by plasma IgG of the full-length VAR2CSA protein of the 3D7 parasite strain (3D7-VAR2CSA), the CSA-binding multidomains 3D7-DBL1X to -DBL3X (3D7-DBL1X-3X), and the CSA nonbinding multidomains 3D7-DBL4ε to -DBL6ε (3D7-DBL4ε-6ε), as well as individual 3D7-DBL domains. Our results revealed a parity-dependent recognition of the full-length 3D7-VAR2CSA and of the CSA-binding region, 3D7-DBL1X-3X. Indeed, multigravid women possess significantly higher levels of antibodies directed against these constructs than primigravidae. Our results suggest an important role of antibodies targeting the CSA-binding region in the development of immunity against PAM, therefore providing new insights on how natural protection might be acquired and further information for the design of VAR2CSA-based vaccines.
Investigation of the Electrical Impedance of Acupuncture Points and Non-Acupuncture Points before and after Acupuncture, using a Four-Electrode Device
Authors: Khorsand Ali , Zhu Jiang , Bahrami-Taghanaki Hamidreza , Baghani Sara , Ma Liangxiao , Rezaei Shima 
Published: April 2015

Aim To evaluate the effect of acupuncture on skin electrical impedance of selected points, before and after acupuncture on one acupuncture point (PC6), using a four-electrode device. Methods Six acupuncture and non-acupuncture points on both sides of the body were selected to evaluate the effects of acupuncture on electrical properties of these points. Results There were no results significant differences of electrical impedance before and after acupuncture in the selected points. Conclusions According to our experimental set-up, acupuncture at one point without stimulation does not alter skin electrical impedance in healthy volunteers and there is no difference between acupuncture points and non-acupuncture points.