bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flutter Generation and Control Using Mistuning in a Turbine Rotating Rig
Authors: Corral Roque , Beloki Josu , Calza Paolo , Elliot Robert 
Published: September 2016

The paper describes a free-flutter experiment on a stand-alone low-pressure turbine bladed rotor in a high-speed rotating wind tunnel together with the most relevant design decisions and solutions obtained for a low-reduced frequency cantilever shrouded rotor blade design. The test rotor underwent an experimental campaign with independent control of the shaft speed, pressure ratio and air density levels. Measurements were obtained entirely by means of non-intrusive techniques such as blade tip timing optical probes, and unsteady pressure transducers located in the outer casing of the rig downstream of the rotor. The bladed rotor was designed to flutter under a wide range of operating conditions. The independent effects of the shaft speed and the air density level were thoroughly investigated. It was concluded that, firstly, the higher the density level the higher the level of instability and, secondly, that the vibration amplitude of the rotor blade exhibits a maximum with the shaft speed.
In addition the rotor blades were designed in such a way that additional masses could be mounted in the tip-shrouds to create arbitrary mistuning patterns. Two different mistuning patterns were tested, the first consisted of a classical alternate mistuning pattern designed to suppress flutter whereas a second pattern was designed to halve the vibration amplitude of the tuned bladed-disk. Both objectives were successfully achieved during the experiment.
Experimental Characterization of the Vane Heat Flux Under Pulsating Trailing-Edge Blowing
Authors: Saavedra J. , Paniagua G. , Saracoglu B. H. 
Published: September 2016

The steady improvement of aircraft engine performance has led towards more compact engine cores with increased structural loads. Compact single-stage high-pressure turbines allow high power extraction, operating in the low supersonic range. The shock waves formed at the airfoil trailing edge contribute substantially to turbine losses, mainly due to the shock-boundary layer interactions as well as high-frequency forces on the rotor. We propose to control the vane trailing edge shock interaction with the downstream rotor, using a pulsating vane-trailing-edge-coolant at the rotor passing frequency.
A linear cascade of transonic vanes was investigated at different Mach numbers, ranging from subsonic to supersonic regimes (0.8, 1.1) at two engine representative Reynolds numbers (4 and 6 million). The steady and unsteady heat flux was retrieved using thin-film 2-layered gauges. The complexity of the tests required the development of an original heat transfer post-processing approach. In a single test, monitoring the heat flux data and the wall temperature we obtained the adiabatic wall temperature and the convective heat transfer coefficient.
The right-running trailing edge shock wave impacts on the neighboring vane suction side. The impact of the shock wave on the boundary layer creates a separation bubble, which is very sensitive to the intensity and angle of the shock wave. Increasing the coolant blowing rate induces the shock to be less oblique, moving the separation bubble upstream. A similar effect is caused by the pulsations of the coolant.
A robust empirical parametrization of proton stopping power using dual energy CT
Authors: Taasti Vicki T. , Petersen Jørgen B. B. , Muren Ludvig P. , Thygesen Jesper , Hansen David C. 
Published: September 2016

PurposeIn this study the authors present a new method for estimation of proton stopping power ratios (SPRs) using dual energy CT (DECT), which is robust toward CT noise. The authors propose a parametrization for SPR based directly on the CT numbers in a DECT image set, whereby the intermediate steps of estimating the relative electron density, ρe, and mean excitation energy, I, are avoided.MethodsThe SPR parametrization proposed in this study is a purely empirical fit based on the theoretical SPR values for a list of 34 reference human tissues. To investigate the SPR estimation made with this new method the authors performed a calibration and an evaluation with the method. The authors initially calculated CT numbers using CT energy spectrum characterization parameters obtained from calibration based on a Gammex 467 electron density calibration phantom. These CT numbers were fitted to the theoretical SPR for the reference human tissues using the new SPR parametrization presented in this study. The method was evaluated based on theoretical CT numbers for the reference human tissues. The root‐mean‐square error (RMSE) of the SPR and the proton range error from the continuous slowing down approximation were calculated for the reference human tissues. To test the stability of the parametrization the authors varied the density and elemental composition of the reference human tissues and calculated their new SPR estimates. Further, clinically realistic noise values were added to the theoretical CT numbers to investigate how CT noise affected the estimated water equivalent range through 10 cm of the reference human tissues. All results for the new SPR parametrization were compared to the results obtained using two previously published DECT methods for SPR estimation. Comparisons were also made to a single energy CT (SECT) SPR estimation method, the stoichiometric method, which is commonly used in clinical practise for proton therapy treatment planning.ResultsThe RMSE for the SPR of the 34 reference human tissues using the new SPR parametrization was 0.12%, compared to 0.19% and 0.28% for the two previously published DECT methods. The SPR parametrization was more stable toward variations of the calcium content in the reference human tissues, but less stable toward density variations and changes to the hydrogen content than the two other DECT methods. When adding noise to the theoretical CT numbers the SPR parametrization gave the lowest water equivalent range errors of all four tested SPR estimation methods (maximum error reduced to 0.4 mm). In all cases tested, the new SPR parametrization outperformed the SECT stoichiometric method.ConclusionsThe new SPR parametrization gave lower RMSEs than the two other published DECT methods, and was in particular more robust against added noise. The method has potential for reducing range uncertainty margins in treatment planning of proton therapy.
Outbreak of OXA-48-Producing Klebsiella pneumoniae Involving a Sequence Type 101 Clone in Batna University Hospital, Algeria
Authors: Loucif Lotfi , Kassah-Laouar Ahmed , Saidi Mahdia , Messala Amina , Chelaghma Widad , Rolain Jean-Marc 
Published: September 2016

ABSTRACT

Seven nonredundant ertapenem-resistant
Klebsiella pneumoniae
isolates were collected between May 2014 and 19 January 2015 in the nephrology and hematology units of Batna University Hospital in Algeria. All strains coproduced the
bla
OXA-48
,
bla
CTX-M-15
,
bla
SHV-1
, and
bla
TEM-1D
genes. Six of these isolates belonged to the pandemic clone sequence type 101 (ST101). The
bla
OXA-48
gene was located on a conjugative IncL/M-type plasmid. This is the first known outbreak of OXA-48-producing
K. pneumoniae
isolates involving an ST101 clone in Batna University Hospital.
Antiviral Nucleotide Incorporation by Recombinant Human Mitochondrial RNA Polymerase Is Predictive of Increased
In Vivo
Mitochondrial Toxicity Risk
Authors: Fenaux Martijn , Lin Xiaodong , Yokokawa Fumiaki , Sweeney Zachary , Saunders Oliver , Xie Lili , Lim Siew Pheng , Uteng Marianne , Uehara Kyoko , Warne Robert , Gang Wang , Jones Christopher , Yendluri Satya , Gu Helen , Mansfield Keith , Boisclair Julie , Heimbach Tycho , Catoire Alexandre , Bracken Kathryn , Weaver Margaret , Moser Heinz , Zhong Weidong 
Published: September 2016

ABSTRACT

Nucleoside or nucleotide inhibitors are a highly successful class of antivirals due to selectivity, potency, broad coverage, and high barrier to resistance. Nucleosides are the backbone of combination treatments for HIV, hepatitis B virus, and, since the FDA approval of sofosbuvir in 2013, also for hepatitis C virus (HCV). However, many promising nucleotide inhibitors have advanced to clinical trials only to be terminated due to unexpected toxicity. Here we describe the
in vitro
pharmacology of compound 1, a monophosphate prodrug of a 2′-ethynyluridine developed for the treatment of HCV. Compound 1 inhibits multiple HCV genotypes
in vitro
(50% effective concentration [EC
50
], 0.05 to 0.1 μM) with a selectivity index of >300 (50% cytotoxic concentration [CC
50
], 30 μM in MT-4 cells). The active triphosphate metabolite of compound 1, compound 2, does not inhibit human α, β, or γ DNA polymerases but was a substrate for incorporation by the human mitochondrial RNA polymerase (POLRMT). In dog, the oral administration of compound 1 resulted in elevated serum liver enzymes and microscopic changes in the liver. Transmission electron microscopy showed significant mitochondrial swelling and lipid accumulation in hepatocytes. Gene expression analysis revealed dose-proportional gene signature changes linked to loss of hepatic function and increased mitochondrial dysfunction. The potential of
in vivo
toxicity through mitochondrial polymerase incorporation by nucleoside analogs has been previously shown. This study shows that even moderate levels of nucleotide analog incorporation by POLRMT increase the risk of
in vivo
mitochondrial dysfunction. Based on these results, further development of compound 1 as an anti-HCV compound was terminated.
Triazole Substitution of a Labile Amide Bond Stabilizes Pantothenamides and Improves Their Antiplasmodial Potency
Authors: Howieson Vanessa M. , Tran Elisa , Hoegl Annabelle , Fam Han Ling , Fu Jonathan , Sivonen Kate , Li Xiao Xuan , Auclair Karine , Saliba Kevin J. 
Published: September 2016

ABSTRACT

The biosynthesis of coenzyme A (CoA) from pantothenate and the utilization of CoA in essential biochemical pathways represent promising antimalarial drug targets. Pantothenamides, amide derivatives of pantothenate, have potential as antimalarials, but a serum enzyme called pantetheinase degrades pantothenamides, rendering them inactive
in vivo
. In this study, we characterize a series of 19 compounds that mimic pantothenamides with a stable triazole group instead of the labile amide. Two of these pantothenamides are active against the intraerythrocytic stage parasite with 50% inhibitory concentrations (IC
50
s) of ∼50 nM, and three others have submicromolar IC
50
s. We show that the compounds target CoA biosynthesis and/or utilization. We investigated one of the compounds for its ability to interact with the
Plasmodium falciparum
pantothenate kinase, the first enzyme involved in the conversion of pantothenate to CoA, and show that the compound inhibits the phosphorylation of [
14
C]pantothenate by the
P. falciparum
pantothenate kinase, but the inhibition does not correlate with antiplasmodial activity. Furthermore, the compounds are not toxic to human cells and, importantly, are not degraded by pantetheinase.
Opening the Channel: the Two Functional Interfaces of Pseudomonas aeruginosa OpmH with the Triclosan Efflux Pump TriABC
Authors: Ntreh Abigail T. , Weeks Jon W. , Nickels Logan M. , Zgurskaya Helen I. 
Published: September 2016

ABSTRACT

TriABC-OpmH is an efflux pump from
Pseudomonas aeruginosa
with an unusual substrate specificity and protein composition. When overexpressed, this pump confers a high level of resistance to the biocide triclosan and the detergent SDS, which are commonly used in combinations for antimicrobial treatments. This activity requires an RND transporter (TriC), an outer membrane channel (OpmH), and two periplasmic membrane fusion proteins (TriA and TriB) with nonequivalent functions. In the active complex, TriA is responsible for the recruitment of OpmH, while TriB is responsible for stimulation of the transporter TriC. Here, we used the functional and structural differences between the two membrane fusion proteins to link their functional roles to specific interactions with OpmH. Our results provide evidence that the TriB-dependent stimulation of the TriC transporter is coupled to opening of the OpmH aperture through binding to the interprotomer groove of OpmH.

IMPORTANCE
Multidrug efflux transporters are important contributors to intrinsic and acquired antibiotic resistance in clinics. In Gram-negative bacteria, these transporters have a characteristic tripartite architecture spanning the entire two-membrane cell envelope. How such complexes are assembled and how the reactions separated in two different membranes are coupled to provide efficient efflux of various compounds across the cell envelope remain unclear. This study addressed these questions, and the results suggest a mechanism for functional integration of drug efflux by the inner membrane transporter and opening of the channel for transport across the outer membrane.
Adenovirus Early Proteins and Host Sumoylation
Authors: Sohn Sook-Young , Hearing Patrick 
Published: September 2016

ABSTRACT
The human adenovirus genome is transported into the nucleus, where viral gene transcription, viral DNA replication, and virion assembly take place. Posttranslational modifications by small ubiquitin-like modifiers (SUMOs) are implicated in the regulation of diverse cellular processes, particularly nuclear events. It is not surprising, therefore, that adenovirus modulates and utilizes the host sumoylation system. Adenovirus early proteins play an important role in establishing optimal host environments for virus replication within infected cells by stimulating the cell cycle and counteracting host antiviral defenses. Here, we review findings on the mechanisms and functional consequences of the interplay between human adenovirus early proteins and the host sumoylation system.
Domains relating to the everyday impact of hearing loss, as reported by patients or their communication partner(s): protocol for a systematic review
Authors: Vas Venessa , Akeroyd Michael A , Hall Deborah A 
Published: September 2016

IntroductionHearing loss is a highly prevalent condition that affects around 1 in 6 people in the UK alone. This number is predicted to rise by the year 2031 to a staggering 14.5 million people due to the ageing population of the UK. Currently, the most common intervention for hearing loss is amplification with hearing aid(s) which serve to address the issue of audibility due to hearing loss, but cannot reverse its effects. The consequences of hearing loss are multifaceted, as it is a complex condition that can detrimentally affect various aspects of an individual's life, including communication and personal relationships. The scope of these reported issues is so broad that it calls on the need for patient-centred management plans that are tailored to each patient as well as appropriate measures to assess intervention benefit. It is unclear whether current outcome instruments adequately match what patients report as the most important problems for them.Methods and analysisThe systematic review aims to capture existing knowledge about patients and their communication partner's perspective on the everyday impact of hearing loss. Methods are defined according to the Preferred Reporting Items for Systematic reviews and Meta-analyses for Protocols (PRISMA-P) 2015.Ethics and disseminationNo ethical issues are foreseen. Findings will be reported in student's thesis as well as at national and international ENT/audiology conferences and in a peer-reviewed journal.Systematic review registration numberPROSPERO CRD42015024914.
Significance of coexistent granulomatous inflammation and lung cancer
Authors: Dagaonkar Rucha S , Choong Caroline V , Asmat Atasha Binti , Ahmed Dokeu Basheer A , Chopra Akhil , Lim Albert Y H , Tai Dessmon Y H , Kor Ai Ching , Goh Soon Keng , Abisheganaden John , Verma Akash 
Published: September 2016

AimsCoexistence of lung cancer and granulomatous inflammation in the same patient confuses clinicians. We aimed to document the prevalence, clinicopathological features, treatment outcomes and prognosis in patients with coexisting granulomatous inflammation undergoing curative lung resection for lung cancer, in a tuberculosis (TB)-endemic country.MethodsAn observational cohort study of patients with lung cancer undergoing curative resection between 2012 and 2015 in a tertiary centre in Singapore.ResultsOne hundred and twenty-seven patients underwent lung resection for cancer, out of which 19 (14.9%) had coexistent granulomatous inflammation in the resected specimen. Median age was 68 years and 58.2% were males. Overall median (range) survival was 451 (22–2452) days. Eighteen (14%) patients died at median duration of 271 days after surgery. The postsurgery median survival for those alive was 494 (29–2452) days in the whole group. Subgroup analysis did not reveal any differences in age, gender, location of cancer, radiological features, type of cancer, chemotherapy, history of TB or survival in patients with or without coexistent granulomatous inflammation.ConclusionsIncidental detection of granulomatous inflammation in patients undergoing lung resection for cancer, even in a TB-endemic country, may not require any intervention. Such findings may be due to either mycobacterial infection in the past or ‘sarcoid reaction’ to cancer. Although all patients should have their resected specimen sent for acid-fast bacilli culture and followed up until the culture results are reported, the initiation of the management of such patients as per existing lung cancer management guidelines does not affect their outcome adversely.
A survey on internet usage and online learning behaviour among medical undergraduates
Authors: Venkatesh Soma , Chandrasekaran Venkatesh , Dhandapany Gunasekaran , Palanisamy Soundararajan , Sadagopan Srinivasan 
Published: September 2016

ABSTRACTAimTo determine the magnitude and pattern of internet usage by undergraduate medical students to retrieve medical information.Materials and methodsA pretested questionnaire-based survey was conducted among undergraduate medical students who were willing to participate. The institute ethics committee approved the study. The responses of students to the questionnaire were analysed using VassarStats online statistical programme. Categorical variables were expressed as proportions. To determine the significance of the difference between proportions, the χ2 test or Fisher’s exact test was used. Log-linear analysis was performed for significance of association among interacting variables. A p value &lt;0.05 was considered significant.ResultsA total of 115 undergraduate medical students participated in the survey. The response was 100% and involved mainly IX and VIII semester students. Internet usage was found to be 97.4%. Of the students interviewed, 35.7% were frequent internet users and 57.4% used their mobile phones to access the internet. The majority (60.9%) had their own portable 3G internet connection. Monthly expenditure for the majority (82.6%) was less than 1000 Indian Rupees per month. The most popular medical site accessed by students was Medscape, followed by Wikipedia and WebMD. Of the students studied, 8% had attended one or more online continuing medical education programmes. On log-linear analysis, a linear relationship was found for medical time and social time.ConclusionsAn encouraging trend is seen in the use of the internet by medical students to access medical information, but this has not translated into improved online learning behaviour.
Association between bacterial vaginosis and partner concurrency: a longitudinal study
Authors: Kenyon Chris R , Buyze Jozefien , Klebanoff Mark , Brotman Rebecca M 
Published: September 2016

ObjectivesThe study aimed to test if there was an association between prevalent bacterial vaginosis (BV) and women reporting that their partner had other partners at the same time (partner concurrency). This association has not been assessed in a longitudinal cohort.MethodsThe Longitudinal Study of Vaginal Flora recruited a cohort of 3620 non-pregnant women aged 15–44 years who presented for routine primary healthcare at 12 clinics in Birmingham, Alabama. Behavioural questionnaires and vaginal smears were obtained quarterly for a year and BV was defined by a Nugent score 7 or higher as well as Amsel criteria. Mixed effects logistic regression was used to assess the relationship between prevalent BV and reporting that one's partner had other partners in the preceding 3–6 months time interval.ResultsNugent score prevalent BV was associated with both reporting that one's partner definitely (adjusted OR (aOR) 1.5; 95% CI 1.2 to 1.8) and possibly (aOR 1.5; 95% CI 1.2 to 1.8) engaged in partner concurrency in the preceding 3–6 months time period. Prevalent BV diagnosed by Amsel criteria was similar.ConclusionsA diagnosis of prevalent BV was associated with reporting that one's partner possibly or definitely engaged in partner concurrency.
H → γγ, gauge invariance, and the hierarchy problem
Authors: Kile Jennifer 
Published: September 2016

The calculation of [Formula: see text] displays interesting behavior which depends on the regulator used in the integration over loop momenta. If calculated using a gauge-invariant regulator, such as dimensional regularization, the calculation yields a unique, finite, gauge-invariant result. If four-dimensional symmetric regulation is used without finite subtractions, additional pieces occur which spoil QED gauge invariance. In both cases, a finite result is obtained, but the particular finite result depends on the regulator utilized in the calculation. While gauge-invariant regulators such as dimensional regularization are normally used, four-dimensional symmetric integration is also physically motivated. Also, the gauge-invariance-violating terms that arise using four-dimensional symmetric integration are of the same form for the fermionic, scalar, and the SM [Formula: see text] loop calculated in renormalizable gauge. This presents an interesting possibility. Inspired by anomaly cancellation, we ask if it is possible that these gauge-invariance-violating terms may cancel in certain models when contributions from all diagrams are included. Here, we calculate the regulator-dependent contributions to [Formula: see text] arising from generic fermion and scalar loops, as well as the Standard Model [Formula: see text] loop contribution, which we evaluate in renormalizable gauge for general [Formula: see text]. We find that a cancellation between such terms is possible, and derive the cancellation condition. Additionally, we find that this cancellation condition ensures QED gauge invariance without finite subtractions for any regulator used, not just for four-dimensional symmetric integration. We additionally relate the regulator-dependent terms in [Formula: see text] to the behavior of quadratically-divergent Higgs tadpole diagrams under shifts of internal loop momentum. Thus, the cancellation condition for the gauge-invariance-violating terms in [Formula: see text] implies a relation between the quadratic divergences in Higgs tadpole diagrams; this has consequences for hypothesized solutions to the hierarchy problem. Lastly, we find that the MSSM obeys our cancellation condition.