bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of Brain Atrophy, Disability, and Spinal Cord Atrophy in a Murine Model of Multiple Sclerosis
Authors: Paz Soldán M. Mateo , Raman Mekala R. , Gamez Jeffrey D. , Lohrey Anne K. , Chen Yi , Pirko Istvan , Johnson Aaron J.
Published: April 2015

BACKGROUND

Disability progression in multiple sclerosis (MS) remains incompletely understood. Unlike lesional measures, central nervous system atrophy has a strong correlation with disability. Theiler's murine encephalomyelitis virus infection in SJL/J mice is an established model of progressive MS. We utilized in vivo MRI to quantify brain and spinal cord atrophy in this model and analyzed the temporal relationship between atrophy and disability.

METHODS

Infected and control mice were followed for 12 months. Disability was assessed periodically using rotarod assay. Volumetric MRI datasets were acquired at 7 Tesla. Ventricular volume and C4‐5 spinal cord cross‐sectional area measurements were performed using Analyze 10.

RESULTS

At 3 months, brain atrophy reached statistical significance (P = .005). In contrast, disability did not differ until 4 months post‐infection (P = .0005). Cord atrophy reached significance by 9 months (P = 0.009). By 12 months, brain atrophy resulted in 111.8% increased ventricular volume (P = .00003), while spinal cord cross‐sectional area was 25.6% reduced (P = .001) among cases.

CONCLUSIONS

Our results suggest that significant brain atrophy precedes and predicts the development of disability, while spinal cord atrophy occurs late and correlates with severe disability. The observed temporal relationship establishes a framework for mechanisms of disability progression and enables further investigations of their underlying substrate.
Melatonin modulates the fetal cardiovascular defense response to acute hypoxia
Authors: Thakor Avnesh S. , Allison Beth J. , Niu Youguo , Botting Kimberley J. , Serón‐Ferré Maria , Herrera Emilio A. , Giussani Dino A.
Published: April 2015

Experimental studies in animal models supporting protective effects on the fetus of melatonin in adverse pregnancy have prompted clinical trials in human pregnancy complicated by fetal growth restriction. However, the effects of melatonin on the fetal defense to acute hypoxia, such as that which may occur during labor, remain unknown. This translational study tested the hypothesis, in vivo, that melatonin modulates the fetal cardiometabolic defense responses to acute hypoxia in chronically instrumented late gestation fetal sheep via alterations in fetal nitric oxide (NO) bioavailability. Under anesthesia, 6 fetal sheep at 0.85 gestation were instrumented with vascular catheters and a Transonic flow probe around a femoral artery. Five days later, fetuses were exposed to acute hypoxia with or without melatonin treatment. Fetal blood was taken to determine blood gas and metabolic status and plasma catecholamine concentrations. Hypoxia during melatonin treatment was repeated during in vivo NO blockade with the NO clamp. This technique permits blockade of de novo synthesis of NO while compensating for the tonic production of the gas, thereby maintaining basal cardiovascular function. Melatonin suppressed the redistribution of blood flow away from peripheral circulations and the glycemic and plasma catecholamine responses to acute hypoxia. These are important components of the fetal brain sparing response to acute hypoxia. The effects of melatonin involved NO‐dependent mechanisms as the responses were reverted by fetal treatment with the NO clamp. Melatonin modulates the in vivo fetal cardiometabolic responses to acute hypoxia by increasing NO bioavailability.
Quality of Life and Psychological Adjustment of Women Living with 46,XY Differences of Sex Development
Authors: D'Alberton Franco , Assante Maria Teresa , Foresti Maura , Balsamo Antonio , Bertelloni Silvano , Dati Eleonora , Nardi Laura , Bacchi Maria Letizia , Mazzanti Laura
Published: April 2015

Background

Progressive care improvement for differences of sex development (DSD), regarding diagnosis communication, psychological, medical and surgical management has been claimed.

Aim of the study

To assess clinical management, quality of life (QoL) and the general psychosocial adjustment of individuals with 46,XY DSD. Some differences related to age at diagnosis are investigated.

Design

Cross-sectional study using standardized questionnaires.

Population

Forty-three Caucasian females with 46,XY DSD (self declared diagnoses: complete androgen insensitivity syndrome, n = 34; complete gonadal dysgenesis, n = 1; 5α-reductase deficiency, n = 4; Leydig cell hypoplasia, n = 1; unknown diagnosis, n = 3; age years: 31.5 ± 9.6 [range 18–57 years]).

Setting

University Hospitals.

Methods

Subjects were required to fill in questionnaires (ABCL, WHOQOL, dedicated 17-item questionnaire). Academic and socioeconomic data were compared with those of the Italian population. QoL and psychological data were compared with those of a comparison group (46,XX healthy females: n = 43; age, years: 34.5 ± 9.7, range 22–51years).

Results

Present sample of women living with 46,XY DSD were well adapted and were higher achievers than controls, both in educational and professional life. They showed good QoL, but they appeared less satisfied in psychological and social areas. They had borderline mean scores and statistically higher scores than the comparison group for depression, anxiety, internalizing and externalizing problems. Younger persons living with a 46,XY DSD showed better psychosocial adjustment than older ones. Younger women showed lower age at diagnosis communication. Psychological support was more often proposed at the time of diagnosis communication to younger individuals, and they undertook it more frequently than older ones.

Conclusions

Italian people living with 46,XY DSD were well adapted and successful; they reported a good QoL but showed higher degree of psychological distress than the comparison group. Lower psychological distress in younger women could indicate some positive effects of changes in management.
Increase in nonhepatic diagnoses among persons with hepatitis C hospitalized for any cause, United States, 2004–2011
Authors: Tong X. , Spradling P. R.
Published: April 2015

Although persons with hepatitis C virus (HCV) infection may experience nonhepatic illnesses, little is known about the frequency of and trends in such conditions in a population‐based sample of HCV‐infected persons. Using hospitalization data collected during 2004–2011 from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project, we examined trends in comorbidities among all hospitalizations that included either a principal or secondary HCV diagnostic code (i.e., HCV was not necessarily the cause for hospitalization). We also compared comorbidities among all persons aged 45–64 years hospitalized with and without principal or secondary HCV diagnostic codes. The estimated number of hospitalizations among persons with HCV infection increased from 850 490 in 2004–2005 to 1 178 633 in 2010–2011; mean age at hospitalization was 50 years in 2004–2005 and 52.5 years in 2010–2011. There were significant increases in the prevalence of most medical and psychiatric comorbidities; the largest were for lipid disorders, chronic kidney disease and obesity. Among HCV‐infected aged 45–64 persons hospitalized for any cause, the prevalence of alcohol /substance abuse, mental disorders, chronic kidney disease, pneumonia, hepatitis B virus infection and HIV infection were significantly higher than those aged 45–64 persons hospitalized without HCV infection (P < 0.001 for all). The prevalence of cryoglobulinaemia, vasculitis, nephrotic syndrome or membranoproliferative glomerulonephritis and porphyria cutanea tarda among hospitalizations with HCV infection was consistently low during the study period (i.e., <0.5%). The increase we observed in nonhepatic comorbidities associated with a high risk of HCV‐related complications has important implications for the current HCV treatment recommendations in a greatly expanded treatment population.
Nanoemulsion formulation of florfenicol improves bioavailability in pigs
Authors: Zhang Q. , Tang S.‐S. , Qian M.‐Y. , Wei L. , Zhou D. , Zhang Z.‐J. , He J.‐K. , Zhang Q.‐J. , Zhu P. , Xiao X.‐L.
Published: April 2015

Nanotechnology applications in medicine have seen a tremendous growth in the past decade and are being employed to enhance the stability and bioavailability of lipophilic substances, such as florfenicol. This study aimed to examine the pharmacokinetic properties of the formulated oil‐in‐water florfenicol‐loaded nanoemulsion (FF‐NE). FF‐NE and florfenicol control (Nuflor®) were administered to the pigs at a dose of 20 mg/kg. Nanoemulsion formulation of florfenicol was highly influenced in vivo plasma profile. The in vivo absorption study in pigs indicated that Cmax (14.54 μg/mL) was significantly higher in FF‐NE, 3.42 times higher than the marketed formulation. In comparison with the control group, the relative bioavailability of formulated nanoemulsion was up to 134.5%. Assessment of bioequivalence using log‐transformed data showed that the 90% confidence intervals (90% CI) of Cmax and AUC0–∞ were 2.48–4.60 and 1.21–1.72, respectively.
Synthesis of refractory metal nuggets and constraints on the thermal histories of nugget‐bearing Ca, Al‐rich inclusions
Authors: Schwander D. , Buhre S. , Schönhense G. , Ott U.
Published: April 2015

Tiny refractory metal nuggets are mainly observed inside Ca, Al‐rich inclusions (CAIs) from chondritic meteorites and are commonly assumed to be condensates from a solar composition gas. However, recent detailed studies of metal nugget compositions and their comparison with predictions from condensation show that the observed abundance patterns are extremely difficult to achieve in this way. As a test for the proposed alternative, precipitation from a silicate liquid, we conducted melting experiments, in which nine different refractory metals (nugget components) were equilibrated with each other along with a CAI‐like liquid at reducing conditions. When quenched, minerals similar to those in CAIs formed from such liquids including refractory metal nuggets exhibiting compositions and appearances similar to those of the meteoritic nuggets. The run products and their comparison with a meteoritic nugget‐bearing CAI is evidence for formation of refractory metal nuggets during cooling of Ca, Al‐rich liquids at rates about 1000°/40 s (in the interval from 1900 to 900 °C). To achieve the formation of refractory metal nuggets and the textures observed in the host inclusions, during cooling the rate probably changed. Refractory metal nuggets apparently formed during quenching before spinel crystallized.
Outpatient Home‐based Wet Wrap Dressings with Topical Steroids with Children with Severe Recalcitrant Atopic Dermatitis: A Feasibility Pilot Study
Authors: Leloup Pauline , Stalder Jean‐François , Barbarot Sébastien
Published: April 2015

Wet wrapping (WW) appears to be effective in severe atopic dermatitis (AD) in children resistant to topical treatment. Seventeen children were included and were directed to use WW every night (≥6 hr) until lesions disappeared, followed by maintenance treatment of two to three treatments per week. The mean Scoring Atopic Dermatitis (SCORAD) score at baseline was 48.9. After 1 month of treatment the mean SCORAD score was 18.9, and efficacy was maintained after 3 months of treatment. The majority of patients were satisfied (91.7%) with the WW treatment; 92% considered it to be much more effective than the previous treatments received. WW was easy to perform for 75% of patients, 83% of patients stated that it was better tolerated, and 17% considered it to be tolerated equally to dermatologic corticosteroids without WW. The home WW program was continued on a maintenance basis for 75% of patients. This open‐label study showed that this program was a feasible and well‐tolerated alternative for the treatment of severe, refractory AD in children and adolescents.
How inappropriate high‐pass filters can produce artifactual effects and incorrect conclusions in ERP studies of language and cognition
Authors: Tanner Darren , Morgan‐Short Kara , Luck Steven J.
Published: April 2015

Although it is widely known that high‐pass filters can reduce the amplitude of slow ERP components, these filters can also introduce artifactual peaks that lead to incorrect conclusions. To demonstrate this and provide evidence about optimal filter settings, we recorded ERPs in a typical language processing paradigm involving syntactic and semantic violations. Unfiltered results showed standard N400 and P600 effects in the semantic and syntactic violation conditions, respectively. However, high‐pass filters with cutoffs at 0.3 Hz and above produced artifactual effects of opposite polarity before the true effect. That is, excessive high‐pass filtering introduced a significant N400 effect preceding the P600 in the syntactic condition, and a significant P2 effect preceding the N400 in the semantic condition. Thus, inappropriate use of high‐pass filters can lead to false conclusions about which components are influenced by a given manipulation. The present results also lead to practical recommendations for high‐pass filter settings that maximize statistical power while minimizing filtering artifacts.
Exon sequencing identifies a novel CHRNA3‐CHRNA5‐CHRNB4 variant that increases the risk for chronic obstructive pulmonary disease
Authors: Zhao Zhuxiang , Peng Fang , Zhou Yumin , Hu Guoping , He Hua , He Fang , Zou Weifeng , Zhao Ziwen , Li Bing , Ran Pixin
Published: April 2015

Background and objective

Recent genome‐wide association studies have established that single nucleotide polymorphisms in the CHRNA3‐CHRNA5‐CHRNB4 genes are susceptibility loci for chronic obstructive pulmonary disease COPD. However, further effort is still required to reveal their genetic contribution to COPD, considering the existence of ‘missing heritability’, which may be mediated by variants that are of a low frequency or rare. Here we aimed to identify genetic variants in the coding regions of the CHRNA3‐CHRNA5‐CHRNB4 genes and determine their associations with COPD risk in Chinese.

Methods

We directly sequenced the coding regions of the CHRNA3‐CHRNA5‐CHRNB4 genes in 160 Chinese subjects, and then genotyped the missense or synonymous variants that have previously been reported to be associated with COPD risk in a two‐stage case–control study involving 1013 COPD cases and 1030 controls of southern Chinese.

Results

We found nine variants, three of which were missense variations (Ser140Gly, His462Gln and Asp398Asn), while two were synonymous variants (Tyr215Tyr and Val53Val). The variants Ser140Gly, Tyr215Tyr and Asp398Asn were significantly associated with COPD risk. By combining these variants, the number of risk genotypes significantly increased the risk for COPD in a dose‐dependent manner (Ptrend = 5.00 × 10−4). The risk genotype number was also significantly correlated with several lung function parameters, including forced expiratory volume in 1 s (FEV1), FEV1% predicted, FEV1/forced vital capacity ratio and peak expiratory flow.

Conclusions

The present study identified a novel exon variant Ser140Gly, and two previously reported variants Tyr215Tyr and Asp398Asn are significantly associated with COPD risk in Chinese. These variants may be genetic biomarkers for predicting COPD risk in Chinese. Validation in other ethnicities is warranted.
Molecular evidence places the swallow bug genus Oeciacus Stål within the bat and bed bug genus Cimex Linnaeus (Heteroptera: Cimicidae)
Authors: BALVÍN ONDŘEJ , ROTH STEFFEN , VILÍMOVÁ JITKA
Published: April 2015

The genera Cimex Linnaeus and Oeciacus Stål (Heteroptera: Cimicidae) are common haematophagous ectoparasites of bats or birds in the Holarctic region. Both their phylogenetic relationship and the systematics of the entire family previously were based on data from morphology and host relationships. Relationships among nine species of the genus Cimex and three species of the genus Oeciacus were analysed here using two mitochondrial and three nuclear genes. Cimex was shown to be paraphyletic with respect to Oeciacus. Oeciacus is thus proposed as a synonym of Cimex. The characteristic phenotype of Oeciacus results from the specific host association with different species of swallows (Hirundinidae). The morphological characters that have been used as diagnostic for the genera were shown to be valid and can be further used for determination at species level. The present analyses recovered the four traditional morphologically defined species groups of the genus Cimex. However, their relationships were poorly resolved – only the C. hemipterus group showed a well‐supported relationship to the C. pipistrelli group. The molecular differentiation within the Palaearctic C. pipistrelli and the Nearctic C. pilosellus species groups correlates with their karyotype differentiation. Furthermore, the analyses suggest poly‐ or paraphyly of the former genus Oeciacus. Either way this indicates there is a large amount of host‐associated phenotypic convergence in either bat‐ or bird‐associated groups of species. The probability of host choice and subsequent switch in Cimicidae are discussed and possible scenarios of the evolution of host association in species of Cimex are suggested.
Chromatin remodelling during male gametophyte development
Authors: Borg Michael , Berger Frédéric
Published: April 2015

The plant life cycle alternates between a diploid sporophytic phase and haploid gametophytic phase, with the latter giving rise to the gametes. Male gametophyte development encompasses two mitotic divisions that results in a simple three‐celled structure knows as the pollen grain, in which two sperm cells are encased within a larger vegetative cell. Both cell types exhibit a very different type of chromatin organization – highly condensed in sperm cell nuclei and highly diffuse in the vegetative cell. Distinct classes of histone variants have dynamic and differential expression in the two cell lineages of the male gametophyte. Here we review how the dynamics of histone variants are linked to reprogramming of chromatin activities in the male gametophyte, compaction of the sperm cell genome and zygotic transitions post‐fertilization.
Assessing Mitochondrial Movement Within Neurons: Manual Versus Automated Tracking Methods
Authors: Bros Helena , Hauser Anja , Paul Friedemann , Niesner Raluca , Infante‐Duarte Carmen
Published: April 2015

Owing to the small size of mitochondria and the complexity of their motility patterns, mitochondrial tracking is technically challenging. Mitochondria are often tracked manually; however, this is time‐consuming and prone to measurement error. Here, we examined the suitability of four commercial and open‐source software alternatives for automated mitochondrial tracking in neurons compared with manual measurements. We show that all the automated tracking tools dramatically underestimated track length, mitochondrial displacement and movement duration, with reductions ranging from 45 to 77% of the values obtained manually. In contrast, mitochondrial velocity was generally overestimated. Only the number of motile mitochondria and their directionality were similar between strategies. Despite these discrepancies, we show that automated tools successfully detected transport alterations after applying an oxidant agent. Thus, automated methods appear to be suitable for assessing relative transport differences between experimental groups, but not for absolute quantification of mitochondrial dynamics. Although useful for objective and time‐efficient measurements of mitochondrial movements, results provided by automated methods should be interpreted with caution.
Head‐to‐head comparison between two screening systems for HBsAG, anti‐HBc, anti‐HCV and HIV combination immunoassays in an international, multicentre evaluation study
Authors: Schmidt M. , Jimenez A. , Mühlbacher A. , Oota S. , Blanco L. , Sakuldamrongpanich T. , Schennach H. , Seifried E.
Published: April 2015

Background

Mandatory screening of blood donations for hepatitis B and hepatitis C viruses and human immunodeficiency viruses 1 and 2 requires assays with exceptional sensitivity and specificity. This study reports the results from a direct head‐to‐head comparison of the Elecsys HBsAG II, Elecsys Anti‐HBc, Elecsys Anti‐HCV II and Elecsys HIV combi PT immunoassays with the respective ABBOTT PRISM/Architect instrument immunoassays in a multicentre blood bank evaluation study.

Study Design and Methods

Assay validation was performed in the blood screening laboratories of four blood bank centres in Austria, Germany, Spain and Thailand, where both first‐time donor samples (approximately 6000 donors) and repeat donor samples (approximately 14 000 donors) were screened.

Results

Of all screened donor samples, 93 (0·46%) were confirmed to be positive using assays from both manufacturers. The specificity of all immunoassays was >99·5% and was comparable between first‐time and multiple‐time donors. A direct comparison between the assays from Roche and ABBOTT according to Bland and Altman analysis demonstrated equivalent quality.

Conclusions

These results suggest that the Elecsys immunoassays for HBV, HCV and HIV infection, with a comparative sensitivity of 100% and a specificity exceeding the common technical specification threshold of >99·5%, meet the stringent performance criteria stipulated for blood donor screening for these infectious agents. Significant differences in the specificity between first‐time and repeat donors were not detectable.
Effect of Particle Concentration on Shape Deformation and Secondary Atomization Characteristics of a Burning Nanotitania Dispersion Droplet
Authors: Miglani Ankur , Basu Saptarshi
Published: April 2015

Secondary atomization characteristics of burning bicomponent (ethanol–water) droplets containing titania nanoparticles (NPs) in dilute (0.5% and 1 wt.%) and dense concentrations (5% and 7.5 wt.%) are studied experimentally at atmospheric pressure under normal gravity. It is observed that both types of nanofuel droplets undergo distinct modes of secondary breakup, which are primarily responsible for transporting particles from the droplet domain to the flame zone. For dilute nanosuspensions, disruptive response is characterized by low intensity atomization modes that cause small-scale localized flame distortion. In contrast, the disruption behavior at dense concentrations is governed by high intensity bubble ejections, which result in severe disruption of the flame envelope.
A Robust Design Optimization Framework for Systematic Model-Based Calibration of Engine Control Systems
Authors: Borhan Hoseinali , Hodzen Edmund
Published: April 2015

In this paper, a systematic model-based calibration framework basing on robust design optimization technique is developed for engine control system. In this framework, the control system is calibrated in an optimization fashion where both performance and robustness of the closed-loop system to uncertainties are optimized. The proposed calibration process has three steps: in the first step, the optimal performance of the system at the nominal conditions, where the effects of uncertainties are ignored, is computed by formulation of the controller calibration as an optimization problem. The capabilities of the controller are fully explored at nominal conditions. In the second step, the robustness and sensitivity of a selected control design to the system uncertainties are analyzed using Monte Carlo simulation. In the third step, robust design optimization is applied to optimize both performance and robustness of the closed-loop system to the uncertainties. The robustness capabilities of the controller are fully explored and the one that satisfies both performance and robustness requirements is selected. This process is implemented for the calibration of an advanced diesel air path control system with a variable geometry turbocharger (VGT) and dual loop exhaust gas recirculation (EGR) architecture.
Advances in Horizontal Axis Wind Turbine Blade Designs: Introduction of Slots and Tubercle
Authors: Ibrahim Mohamed , Alsultan Abdulrahman , Shen Shaohua , Amano Ryoichi S.
Published: April 2015

Despite being harvested thousands of years ago, wind energy was neglected during the industrial revolution because of the strong dependence on fossil fuels. However, after the alarming decrease in the fossil fuels reserves, many have drawn their attentions back to a renewable energy technology, especially the wind energy. This paper presents some of the new designs that are being tested, including slotted blades and tubercles design models. The experimental results are used to validate the numerical studies that are being conducted parallel to the experiments for better understanding and more detailed results. The new slotted blade design produced more power compared to the straight blade for lower wind speeds, while the tubercle blades showed better power performance in severe wind conditions and a more steady behavior under unsteady and higher wind velocities.
A Multicomponent Blend as a Diesel Fuel Surrogate for Compression Ignition Engine Applications
Authors: Pei Yuanjiang , Mehl Marco , Liu Wei , Lu Tianfeng , Pitz William J. , Som Sibendu
Published: April 2015

A mixture of n-dodecane and m-xylene is investigated as a diesel fuel surrogate for compression ignition (CI) engine applications. Compared to neat n-dodecane, this binary mixture is more representative of diesel fuel because it contains an alkyl-benzene which represents an important chemical class present in diesel fuels. A detailed multicomponent mechanism for n-dodecane and m-xylene was developed by combining a previously developed n-dodecane mechanism with a recently developed mechanism for xylenes. The xylene mechanism is shown to reproduce experimental ignition data from a rapid compression machine (RCM) and shock tube (ST), speciation data from the jet stirred reactor and flame speed data. This combined mechanism was validated by comparing predictions from the model with experimental data for ignition in STs and for reactivity in a flow reactor. The combined mechanism, consisting of 2885 species and 11,754 reactions, was reduced to a skeletal mechanism consisting 163 species and 887 reactions for 3D diesel engine simulations. The mechanism reduction was performed using directed relation graph (DRG) with expert knowledge (DRG-X) and DRG-aided sensitivity analysis (DRGASA) at a fixed fuel composition of 77% of n-dodecane and 23% m-xylene by volume. The sample space for the reduction covered pressure of 1–80 bar, equivalence ratio of 0.5–2.0, and initial temperature of 700–1600 K for ignition. The skeletal mechanism was compared with the detailed mechanism for ignition and flow reactor predictions. Finally, the skeletal mechanism was validated against a spray flame dataset under diesel engine conditions documented on the engine combustion network (ECN) website. These multidimensional simulations were performed using a representative interactive flame (RIF) turbulent combustion model. Encouraging results were obtained compared to the experiments with regard to the predictions of ignition delay and lift-off length at different ambient temperatures.
A New Small Power Output Gas Turbine Concept
Authors: Berchtold Max , Lutz T. W.
Published: April 2015

The proposed gas turbine engine represents a combination of a turbo-supercharger with a Comprex pressure exchanger. The engine is expected to have without recuperator a fuel consumption comparable to gasoline reciprocating engines. The availability of high quality low cost turbomachines as a result of the turbocharger development on the one side and the knowledge of non-steady flow machine technology acquired in the development of Comprex supercharger make this engine combination promising in the sizes of 50 to 100 KW output. The paper will give informations on thermodynamic parameters. The proposed arrangement of engine-components will be shown.
Regenerator Development for the British Leyland 2S/350/R Gas Turbine Engine
Authors: Ritchie J. A. , Phillips P. A. , Barnard M. C. S.
Published: April 2015

This paper describes the application of the ceramic regenerator to the British Leyland truck gas turbine. Aspects of mounting, driving and sealing the heat exchanger disk are covered with particular reference to the single disk version of the 2S/350/R engine.
An Experimental Study of Heat Transfer and Film Cooling on Large-Scale Turbine Endwalls
Authors: Blair M. F.
Published: April 2015

Experiments were conducted to determine the film cooling effectiveness and convective heat transfer coefficient distributions on the endwall of a large-scale turbine vane passage. The vane test models employed simulated the passage geometry and upstream cooling slot geometry of a typical first-stage turbine. The test models were constructed of low thermal conductivity foam and foil heaters. The tests were conducted at a typical engine Reynolds number but at lower than typical Mach numbers. The film cooling effectiveness distribution for the entire endwall and the heat transfer distribution for the downstream one-half of the endwall were characterized by large gapwise variations which were attributed to a secondary flow vortex.
Recent Status on Development of the Turbofan Engine in Japan
Authors: Matsuki Masakatsu , Torisaki Tadao , Miyazawa Kiyoto
Published: April 2015

Efforts to design and develop new jet engines have been made in Japan since 1953. One family of propulsion engine (J3) succeeded in getting into production to be installed on two models of Japanese developed aircraft (T1B and P2J). Another family of lift engine (JR) has been successfully used for overall VTOL system studies. Based upon these experiences, studies on a new fan engine for main propulsion are being carried out. This new engine (FJR-710) is a high bypass front fan engine developed for low noise generation and low smoke emission.
The Limit Load of Transonic Turbine Blading
Authors: Fruchtman I.
Published: April 2015

Limit load represents the maximum tangential velocity or blade force that can be generated within a transonic turbine blade. Its accurate prediction is therefore extremely important if the expected thermal efficiency and power output from the turbine is to be obtained. This report presents methods of calculating limit load for typical transonic turbine blading. Comparisons are made between predictions and test data from: (a) two-dimensional stationary cascade and (b) model low pressure turbine with dry steam. Satisfactory agreement is shown between the predictive techniques and the test values of maximum tangential velocity.
Excess Noise From Gas Turbine Exhausts
Authors: Cumpsty N. A.
Published: April 2015

There is evidence to show that the exhaust noise from gas turbines contains components which exceed the jet mixing noise at low jet velocities. This paper describes a theory developed to calculate the acoustic power produced by temperature fluctuations from the combustor entering the turbine. Using the turbine Mach numbers and flow directions at blade mid-height, and taking a typical value for the fluctuation in temperature, it has been possible to predict the acoustic power due to this mechanism for three different engines. In all three cases the agreement with measurements of acoustic power at low jet velocities is very good. Using a measured spectrum of the temperature fluctuation the prediction of the acoustic power spectrum agrees quite well with that measured.
Process Systems for Conversion of Difficult Fuels to Synthetic Fuels for Baseload Gas Turbines
Authors: Ahner D. J. , Boothe W. A.
Published: April 2015

Rapid changes in the fuel availability and cost picture, coupled with environmental concerns, emphasize the need to consider new concepts for power generation by industrial plants and electrical utilities. A number of processes are now being developed to produce clean gaseous and liquid fuels from coal and low-grade petroleum products which offer potential for use in gas turbine-based power generating systems. This paper reviews several of the processes and considers the economic and environmental factors affecting their application to power generation systems.
Hot Gas Ducting, Expansion Joints and Dampers: A Case History
Authors: Wadsworth W. J.
Published: April 2015

A hot gas duct system is described where the exhaust gases from three gas turbines are directed through suitable ducts and dampers to allow the use of any combination of gas turbines with any combination of drying equipment in a process application. Specific problems with the original design and installation are discussed, as well as the design modifications made to overcome them. A list of features to look for to help assure a well designed hot gas ducting system is offered.
NASTRAN Analysis of a Turbine Blade and Comparison With Test and Field Data
Authors: Allen J. M. , Erickson L. B.
Published: April 2015

A NASTRAN finite element analysis of a free standing gas turbine blade is presented. The analysis entails calculation of the first four natural frequencies, mode shapes, and relative vibratory stresses, as well as deflections and stresses due to centrifugal loading. The stiffening effect of the centrifugal force field was accounted for by using NASTRAN’s differential stiffness option. Natural frequencies measured in a rotating test correlated well with computed results. Areas of maximum vibratory stress (fundamental mode) coincided with the three zones of crack initiation observed in a metallographic examination of a fatigue failure. Airfoil stress distributions were found to be significantly different from that predicted by generalized beam theory, especially near the airfoil-platform junction.
Gas Turbine Drive for New High Speed Trains
Authors: Keller Rolf
Published: April 2015

After numerous tests over the last 40 years, the aircraft gas turbine of two-shaft design has emerged as the most promising power unit for high-powered, fast and lightweight rail vehicles of the future. The performance characteristics, superior to those of the diesel engine, are complemented either by an electrical transmission system or a hydraulic transmission unit. The advantage of the gas turbine lies in its compactness and lightness in weight, allowing a doubling of power and savings in space. Viewed from a commercial standpoint, this means a covering of fuel costs. In respect of noise development and exhaust gas emission, the gas turbine is also more favorable than the diesel engine. The most successful series-built vehicles powered by gas turbines are the turbotrains of the SNCF which have also been imported into the USA where they are to be built under license.
Coating Technology for the Marine Gas Turbine Airfoil Application
Authors: Fairbanks J. W.
Published: April 2015

This paper describes two basic processes of aluminide coating applications for gas turbine airfoils — pack cementation and a two-step slurry process — with considerable variation among manufacturer’s processes.
A localized Richardson–Lucy algorithm for fiber orientation estimation in high angular resolution diffusion imaging
Authors: Liu Xiaozheng , Yuan Zhenming , Guo Zhongwei , Xu Dongrong
Published: April 2015

Purpose:

Diffusion tensor imaging is widely used for studying neural fiber trajectories in white matter and for quantifying changes in tissue using diffusion properties at each voxel in the brain. To better model the nature of crossing fibers within complex architectures, rather than using a simplified tensor model that assumes only a single fiber direction at each image voxel, a model mixing multiple diffusion tensors is used to profile diffusion signals from high angular resolution diffusion imaging (HARDI) data. Based on the HARDI signal and a multiple tensors model, spherical deconvolution methods have been developed to overcome the limitations of the diffusion tensor model when resolving crossing fibers. The Richardson–Lucy algorithm is a popular spherical deconvolution method used in previous work. However, it is based on a Gaussian distribution, while HARDI data are always very noisy, and the distribution of HARDI data follows a Rician distribution. This current work aims to present a novel solution to address these issues.

Methods:

By simultaneously considering both the Rician bias and neighbor correlation in HARDI data, the authors propose a localized Richardson–Lucy (LRL) algorithm to estimate fiber orientations for HARDI data. The proposed method can simultaneously reduce noise and correct the Rician bias.

Results:

Mean angular error (MAE) between the estimated Fiber orientation distribution (FOD) field and the reference FOD field was computed to examine whether the proposed LRL algorithm offered any advantage over the conventional RL algorithm at various levels of noise. Normalized mean squared error (NMSE) was also computed to measure the similarity between the true FOD field and the estimated FOD filed. For MAE comparisons, the proposed LRL approach obtained the best results in most of the cases at different levels of SNR and b‐values. For NMSE comparisons, the proposed LRL approach obtained the best results in most of the cases at b‐value = 3000 s/mm2, which is the recommended schema for HARDI data acquisition. In addition, the FOD fields estimated by the proposed LRL approach in regions of fiber crossing regions using real data sets also showed similar fiber structures which agreed with common acknowledge in these regions.

Conclusions:

The novel spherical deconvolution method for improved accuracy in investigating crossing fibers can simultaneously reduce noise and correct Rician bias. With the noise smoothed and bias corrected, this algorithm is especially suitable for estimation of fiber orientations in HARDI data. Experimental results using both synthetic and real imaging data demonstrated the success and effectiveness of the proposed LRL algorithm.
How an Air Stream Can Support a Cupcake
Authors: Jones Evan
Published: April 2015

Variations of a demonstration in which a sheet of paper or a bead is levitated in a grazing stream as from one's breath have been published in several sources.1–4 Even a massive ball can be deflected into the robust flow from a leaf blower.5 The attraction is surprising because it is often quite stable and seems to conflict with the familiar transient repulsion felt from a stream's impact.
Modern Gravitational Lens Cosmology for Introductory Physics and Astronomy Students
Authors: Huwe Paul , Field Scott
Published: April 2015

Recent and exciting discoveries in astronomy and cosmology have inspired many high school students to learn about these fields. A particularly fascinating consequence of general relativity at the forefront of modern cosmology research is gravitational lensing, the bending of light rays that pass near massive objects. Gravitational lensing enables high-precision mapping of dark matter distributions in galaxies and galaxy clusters, provides insight into large-scale cosmic structure of the universe, aids in the search for exo-planets, and may offer valuable insight toward understanding the evolution of dark energy. In this article we describe a gravitational lensing lab and associated lecture/discussion material that was highly successful, according to student feedback. The gravitational lens unit was developed as part of a two-week summer enrichment class for junior and senior high school students. With minor modifications, this lab can be used within a traditional classroom looking to incorporate topics of modern physics (such as in a unit on optics).
The Concurrent Validity of the 3-Day Physical Activity Recall in Australian Youth
Authors: Dollman James , Stanley Rebecca , Wilson Andrew
Published: April 2015

Valid measurement of youth physical activity is important and self-report methods provide convenient assessments at the population level. There is evidence that the validity of physical activity self-report varies by weight category. The aim of this study was to assess the validity of the 3-Day Physical Activity Recall (3DPAR), separately between normal weight and overweight/obese Australian youth. Accelerometer-derived physical activity variables were compared with 3DPAR variables in 155 (77 females) 11- to 14-year-olds from Adelaide, South Australia. In the whole sample, validity coefficients for self-reported moderate and moderate to vigorous physical activity were modest (rs = 0.12-0.31) and similar across gender and weight status categories. Validity coefficients for self-reported vigorous physical activity were much stronger (rs = 0.59-0.73) among overweight/obese than among normal weight participants. The validity of the 3DPAR in this study was low in the whole sample but varied according to physical activity intensity and the weight status of the child. Specifically, the 3DPAR may be appropriate for describing vigorous intensity physical activity among overweight and obese youth.
Drug testing in the patient: Toward personalized cancer treatment
Authors: Coombes R. Charles
Published: April 2015

Delivery of cancer drugs directly into tumors in vivo can indicate cancer sensitivity and predict systemic response (Jonas
et al
. and Klinghoffer
et al
., this issue).
Cracking the bell jar
Authors: Brennand Kristen
Published: April 2015

Lithium and the antidepressant paroxetine inhibit GSK3β through FKBP51.
Acute psychosis in a pregnant patient with Graves’ hyperthyroidism and anti-NMDA receptor encephalitis
Authors: Lu Jesslyn , Samson Susan , Kass Joseph , Ram Nalini
Published: April 2015

A previously healthy 36-year-old woman presented with visual hallucinations and acute psychosis manifested predominantly as hypersexuality. Laboratory testing demonstrated elevated free thyroxine levels, suppressed thyroid-stimulating hormone levels and presence of thyroid-stimulating immunoglobulin andthyroid peroxidase (TPO) antibodiesconsistent with Graves’ disease. Despite achieving biochemical euthyroidism, she remained profoundly hypersexual. She did not respond to additional treatment with antipsychotics and corticosteroids, prompting further evaluation. Cerebrospinal fluid analysis detected pleocytosis, elevated IgG, and presence of antibodies against anti-N-methyl-D-aspartate receptor (NMDAR), glutamic acid decarboxylase 65 and TPO. These results suggested a diagnosis of anti-NMDAR encephalitis. Prior to initiation of immunomodulator therapy, she was discovered to be pregnant with date of conception around the time of her original presentation. She received plasmapheresis with resolution of psychosis and decrease in free thyroxine levels. Graves’ disease remitted during the remainder of the pregnancy but relapsed 5 months post partum. She has not had further neuropsychiatric symptoms.
Reactivation of Giardia lamblia cysts after exposure to low-pressure UV irradiation
Authors: Shin Gwy-Am , Linden Karl G.
Published: April 2015

In this study, we determined the repair capabilities of Giardia lamblia cysts when they were exposed to low-pressure (LP) UV and then 4 different repair conditions. A UV collimated beam apparatus was used to expose shallow suspensions of G. lamblia cysts in buffered reagent water (PBS, pH 7.2) to various doses of LP UV irradiation. After UV irradiation, samples were exposed to 4 repair conditions (light and dark repair conditions with 2 temperatures (25 °C and 37 °C) for each condition). The inactivation of G. lamblia cysts by LP UV was very extensive (∼5 log10) even with a low dose of LP UV (1 mJ/cm2). More importantly, there was significant restoration of infectivity in G. lamblia cysts when they were exposed to a low dose of LP UV and then to all the repair conditions tested. Overall, the results of this study indicate that G. lamblia cysts do have the ability to repair their UV-damaged DNA when they are exposed to low doses of LP UV irradiation. This is the first study to report the presence of repair in UV-irradiated G. lamblia cysts.
A 3.6 μW 60 nV/sqrtHz Capacitively-Coupled Instrumentation Amplifier for Biopotential Signal Recordings
Authors: Zhou Yin , Wu Xiaobo , Sun Peng , Zhao Menglian
Published: April 2015

This paper presents a low-power low-noise instrumentation amplifier (IA) intended for biopotential signal recordings. The IA is designed based on a capacitively-coupled topology, which achieves wide input common-mode range, high common-mode rejection ratio (CMRR) and low power consumption. To reduce low-frequency noise and output ripple at the same time, a combination of chopping and ping-pong auto-zeroing techniques, which is normally used in current-feedback IAs, is introduced for the capacitively-coupled topology in this paper. An intrinsic adverse effect of the proposed structure which causes additional ripple is analyzed. The DC electrode offset voltage is suppressed and the input impedance is boosted through feedback techniques. An improved switched-capacitor common mode feedback (SC CMFB) circuit is also presented. Test results show that the IA achieves an equivalent input-referred noise power spectrum density of 60 nV/sqrtHz and a noise efficiency factor (NEF) of 5.58. The bandwidth is 0.5 Hz to 10 kHz, covering most biopotential recording applications. The IA was implemented in 0.18-μm CMOS process. It occupies 0.27 mm2 core area and consumes 3.6 μA from a 1 V supply.
Comparison of Responses of Guyed and Freestanding Transmission Line Towers Under Conductor Breakage Loading
Authors: Alminhana Fábio , Albermani Faris , Mason Matthew
Published: April 2015

Cascades have been a prominent feature of many transmission line (TL) accidents around the world. During these events, a localized member failure changes the boundary conditions of the structural system, magnifying member loads over a considerable extension of the line. This results in the progressive failure of successive support structures. Phase conductor breakage is regarded as the most severe cascade triggering event, generating a shock wave that propagates through the conductor and induces large unbalanced longitudinal loads on the transmission line components. Under such an extreme loading event, nonlinear time-history dynamic analysis has to be employed to predict the response of the TL system. In the present work, an explicit dynamic analysis scheme is developed to predict the response of a multi-span TL section. The analysis includes all the main structural components of a TL section. This procedure was used to investigate the response of two types of suspension steel latticed towers, guyed and freestanding, subjected to conductor breakage loading. Results indicate the occurrence of peak dynamic loads (PDLs), that significantly increase the internal forces in system components, exceeding their design capacities, particularly in tower's members. The results also show that the guyed tower accommodates such a loading event more adequately than the freestanding tower.
Squares: Additive questions and partitions
Authors: Vaughan Robert C.
Published: April 2015

This memoir is concerned with a number of additive questions in which squares occur. For ternary additive problems with at least one square, the exceptional set is considered and it is shown that current methods cannot be sharpened substantially. In a different direction, but using cognate methods, an asymptotic formula is obtained for the number of partitions of a number into squares.