bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual Life Estimation of Axial Compressor Blade of a Turbo-Shaft Engine
Authors: Anbarasan Selwyn , Muthu S. Esakki , Roy Hardik , Udayanan P. , Degaonkar Girish K. 
Published: February 2015

In aeronautical industry, flight safety is the first and foremost concern. Structural failure in aero engine aids to high risk in flight safety and human lives. High Cycle Fatigue (HCF) failure accounts for forty percent of blade structural failure. All critical components in the aero engine are life limited components and are replaced when its prescribed life is reached. Earlier components are designed as per safe-life design philosophy. Ninety percent of the critical components are retired utilizing less than fifty percent of its safe-life capability. Extending the life of component reduces the operating cost and lowers downtime for the fleet operator.
This paper describes the life extension methodology used for a first stage axial compressor blade of turbo-shaft engine. The blade which has completed its safe life in the aircraft in service is identified. The studies are carried out to determine the residual life of the blade to extend the life. First stage axial compressor blade is made from titanium alloy and is fixed with the disc by pins. The force on the blade due to aerodynamic excitation which is required for life estimation is predicted using CFD tools followed by the estimation of alternate stress on the blade using FEM tools. Stress based life estimation methodology is used to estimate HCF life of the blade under engine operating condition. The estimated life of the blade is to be confirmed in rig testing. Life completed blades are identified from different engines for testing of the residual life. Metallurgical studies are carried out on the specimens from the blade to check the residual properties. The blades which qualify after the dimension inspection and crack detection are used for testing residual life. The blades are tested in vibration test rig facility in which incremental fatigue testing method is employed. The blades are excited by the electro-dynamic shaker at its first natural frequency (1F mode) and the amplitude is increased in steps in a steady interval of time. The HCF life of the blade is calculated by Miner’s hypothesis. The residual life of the blade is estimated by vibration rig testing and is compared with the numerical estimation. It is found that the residual life of the life completed component has got potential life of one more overhaul.
Prediction of Fatigue and Fracture Life of an Autofrettaged Turbine Compressor Disc Using Finite Element Analysis
Authors: Jagannath Suman Mittemari Lakshminarayan , Srinivasan Srikari , Gopalakrishnan Mahesh , Banthia Vinod Kumar 
Published: February 2015

Gas turbine compressor discs are highly stressed components as they rotate at high speed. Bore region of the disc is the most critical region because any failure at the bore would lead to catastrophic failure of entire gas turbine. Engine start-up and shutdown, as well as major throttle excursions during operation, induce cyclic tensile stresses in this region. These cyclic tensile stresses can exceed yield strength of the material and can thus lead to low cycle fatigue failure. Hence, there is a strong need to enhance fatigue and fracture life of the bore region in order to meet the growing design life requirements.
In the present work, method of autofrettage to reduce tensile stresses at bore region has been evaluated. In this case, pre-spin has been used to induce compressive pre-stresses in the bore region. A typical gas turbine compressor rotor forward stage disc was modeled based on design parameters available in literature. Analysis was carried out in 2 stages — non-linear structural analysis of pre-spin to induce compressive stresses and then with operation load to evaluate the effect of pre-stress on stresses and fatigue life in operational conditions in the bore region. Stress intensity factor, KI at the bore region was used to calculate fracture life using LEFM methodology.
Comparison of the results for post-spin life with that of the baseline showed 3 times increases in fatigue and 75% increase in fracture life.
Pulmonary nodule detection in CT images based on shape constraint CV model
Authors: Wang Bing , Tian Xuedong , Wang Qian , Yang Ying , Xie Hongzhi , Zhang Shuyang , Gu Lixu 
Published: February 2015

Purpose:Accurate detection of pulmonary nodules remains a technical challenge in computer‐aided diagnosis systems because some nodules may adhere to the blood vessels or the lung wall, which have low contrast compared to the surrounding tissues. In this paper, the analysis of typical shape features of candidate nodules based on a shape constraint Chan–Vese (CV) model combined with calculation of the number of blood branches adhered to nodule candidates is proposed to reduce false positive (FP) nodules from candidate nodules.Methods:The proposed scheme consists of three major stages: (1) Segmentation of lung parenchyma from computed tomography images. (2) Extraction of candidate nodules. (3) Reduction of FP nodules. A gray level enhancement combined with a spherical shape enhancement filter is introduced to extract the candidate nodules and their sphere‐like contour regions. FPs are removed by analysis of the typical shape features of nodule candidates based on the CV model using spherical constraint and by investigating the number of blood branches adhered to the candidate nodules. The constrained shapes of CV model are automatically achieved from the extracted candidate nodules.Results:The detection performance was evaluated on 127 nodules of 103 cases including three types of challenging nodules, which are juxta‐pleural nodules, juxta‐vascular nodules, and ground glass opacity nodules. The free‐receiver operating characteristic (FROC) curve shows that the proposed method is able to detect 88% of all the nodules in the data set with 4 FPs per case.Conclusions:Evaluation shows that the authors’ method is feasible and effective for detection of three types of nodules in this study.
Immunoproteomic Identification ofIn Vivo-Produced Propionibacterium acnes Proteins in a Rabbit Biofilm Infection Model
Authors: Achermann Yvonne , Tran Bao , Kang Misun , Harro Janette M. , Shirtliff Mark E. 
Published: February 2015

ABSTRACTPropionibacterium acnesis well-known as a human skin commensal but can also act as an invasive pathogen causing implant-associated infections. In order to resolve these types ofP. acnesinfections, the implants must be removed, due to the presence of an established biofilm that is recalcitrant to antibiotic therapy. In order to identify thoseP. acnesproteins producedin vivoduring a biofilm infection, we established a rabbit model of implant-associated infection with this pathogen.P. acnesbiofilms were anaerobically grown on dextran beads that were then inoculated into the left tibias of rabbits. At 4 weeks postinoculation,P. acnesinfection was confirmed by radiograph, histology, culture, and PCR.In vivo-produced and immunogenicP. acnesproteins were detected on Western blot using serum samples from rabbits infected withP. acnesafter these bacterial proteins were separated by two-dimensional gel electrophoresis. Those proteins that bound host antibodies were then isolated and identified by tandem mass spectrometry. Radiographs and histology demonstrated a disruption in the normal bone architecture and adherent biofilm communities in those animals with confirmed infections. A total of 24 immunogenic proteins were identified; 13 of these proteins were upregulated in both planktonic and biofilm modes, including an ABC transporter protein. We successfully adapted a rabbit model of implant-associated infection forP. acnesto identifyP. acnesproteins produced during a chronic biofilm-mediated infection. Further studies are needed to evaluate the potential of these proteins for either a diagnostic test or a vaccine to prevent biofilm infections caused byP. acnes.
Genomic and Epidemiological Characteristics Provide New Insights into the Phylogeographical and Spatiotemporal Spread of Porcine Epidemic Diarrhea Virus in Asia
Authors: Sun Min , Ma Jiale , Wang Yanan , Wang Ming , Song Wenchao , Zhang Wei , Lu Chengping , Yao Huochun 
Published: February 2015

ABSTRACTPorcine epidemic diarrhea has become pandemic in the Asian pig-breeding industry, causing significant economic loss. In the present study, 11 complete genomes of porcine epidemic diarrhea virus (PEDV) field isolates from China were determined and analyzed. Frequently occurring mutations were observed, which suggested that full understanding of the genomic and epidemiological characteristics is critical in the fight against PEDV epidemics. Comparative analysis of 49 available genomes clustered the PEDV strains into pandemic (PX) and classical (CX) groups and identified four hypervariable regions (V1 to V4). Further study indicated key roles for the spike (S) gene and the V2 region in distinguishing between the PX and CX groups and for studying genetic evolution. Genotyping and phylogeny-based geographical dissection based on 219 S genes revealed the complexity and severity of PEDV epidemics in Asia. Many subgroups have formed, with a wide array of mutations in different countries, leading to the outbreak of PEDV in Asia. Spatiotemporal reconstruction based on the analysis suggested that the pandemic group strains originated from South Korea and then extended into Japan, Thailand, and China. However, the novel pandemic strains in South Korea that appeared after 2013 may have originated from a Chinese variant. Thus, the serious PED epidemics in China and South Korea in recent years were caused by the complex subgroups of PEDV. The data in this study have important implications for understanding the ongoing PEDV outbreaks in Asia and will guide future efforts to effectively prevent and control PEDV.
Disseminated Rhinovirus C8 Infection with Infectious Virus in Blood and Fatal Outcome in a Child with Repeated Episodes of Bronchiolitis
Authors: Lupo Julien , Schuffenecker Isabelle , Morel-Baccard Christine , Bardet Julie , Payen Valérie , Kaiser Laurent , Constant Samuel , Lobrinus Johannes Alexander , Lin-Marq Nathalie , Lina Bruno , Morand Patrice , Tapparel Caroline 
Published: February 2015

ABSTRACT
We report a fatal case of acute lower respiratory tract disease with human rhinovirus C (HRV-C) as the unique cause in a 19-month-old girl with a history of repeated episodes of bronchiolitis. HRV-C type 8 nucleic acids were observed in respiratory, stool, and cerebrospinal fluid samples, and infectious virions were isolated from patient serum after inoculation onto reconstituted airway epithelia.
Analysis of a Local HIV-1 Epidemic in Portugal Highlights Established Transmission of Non-B and Non-G Subtypes
Authors: Carvalho Alexandre , Costa Patrício , Triunfante Vera , Branca Fernando , Rodrigues Fernando , Santos Catarina L. , Correia-Neves Margarida , Saraiva Margarida , Lecour Henrique , Castro António G. , Pedrosa Jorge , Osório Nuno S. 
Published: February 2015

ABSTRACT
The existing data support Portugal as the western European country with the highest HIV-1 subtype diversity. However, detailed phylogenetic studies of Portuguese HIV-1 epidemics are still scarce. Thus, our main goal was to analyze the phylodynamics of a local HIV-1 infection in the Portuguese region of Minho. Molecular epidemiological analysis was applied to data from 289 HIV-1-infected individuals followed at the reference hospital of the province of Minho, Portugal, at which isolated viruses had been sequenced between 2000 and 2012. Viruses of the G (29.1%) and B (27.0%) subtypes were the most frequent, followed by recombinant forms (17.6%) and the C (14.5%), F1 (7.3%), and A1 (4.2%) subtypes. Multinomial logistic regression revealed that the odds of being infected with the A1 and F1 subtypes increased over the years compared with those with B, G, or C subtypes or recombinant viruses. As expected, polyphyletic patterns suggesting multiple and old introductions of the B and G subtypes were found. However, transmission clusters of non-B and non-G viruses among native individuals were also found, with the dates of the most recent common ancestor estimated to be in the early 2000s. Our study supports that the HIV-1 subtype diversity in the Portuguese region of Minho is high and has been increasing in a manner that is apparently driven by factors other than immigration and international travel. Infections with A1 and F1 viruses in the region of Minho are becoming established and are mainly found in sexually transmitted clusters, reinforcing the need for more efficacious control measures targeting this infection route.
Maturation of Human Herpesvirus 6A Glycoprotein O Requires Coexpression of Glycoprotein H and Glycoprotein L
Authors: Tang Huamin , Mahmoud Nora F. , Mori Yasuko 
Published: February 2015

ABSTRACT
Glycoprotein O (gO) is conserved among betaherpesviruses, but little is known about the maturation process of gO in human herpesvirus 6 (HHV-6). We found that HHV-6 gO maturation was accompanied by cleavage of its carboxyl terminus and required coexpression of gH and gL, which promoted the export of gO out of the endoplasmic reticulum (ER). Finally, we also found that gO was not required for HHV-6A growth in T cells.
The Retinoblastoma Tumor Suppressor Promotes Efficient Human Cytomegalovirus Lytic Replication
Authors: VanDeusen Halena R. , Kalejta Robert F. 
Published: February 2015

ABSTRACT
The retinoblastoma (Rb) tumor suppressor controls cell cycle, DNA damage, apoptotic, and metabolic pathways. DNA tumor virus oncoproteins reduce Rb function by either inducing Rb degradation or physically disrupting complexes between Rb and its myriad binding proteins. Human cytomegalovirus (HCMV), a betaherpesvirus being investigated for potential roles in human cancers, encodes multiple lytic-phase proteins that inactivate Rb in distinct ways, leading to the hypothesis that reduced Rb levels and/or activity would benefit HCMV lytic infection. Paradoxically, we found that Rb knockdown prior to infection, whether transient or constitutive, impaired HCMV lytic infection at multiple stages, notably viral DNA replication, late protein expression, and infectious virion production. The existence of differentially modified forms of Rb, the temporally and functionally distinct means by which HCMV proteins interact with Rb, and the necessity of Rb for efficient HCMV lytic replication combine to highlight the complex relationship between the virus and this critical tumor suppressor.

IMPORTANCE
Initial work examining viral protein modulation of cell cycle progression and oncogenic transformation revealed that these proteins inactivated the function of cellular tumor suppressor proteins. However, subsequent work, including experiments described here using human cytomegalovirus, demonstrate a more nuanced interaction that includes the necessity of cellular tumor suppressors for efficient viral replication. Understanding the positive impacts that cellular tumor suppressors have on viral infections may reveal new activities of these well-studied yet incompletely understood proteins. The basis for oncolytic viral therapy is the selective replication of viruses in transformed cells in which tumor suppressor function may be compromised. Understanding how tumor suppressors support viral infections may allow for the generation of modified oncolytic viruses with greater selective tumor cell replication and killing.
Oncogenic Human T-Cell Lymphotropic Virus Type 1 Tax Suppression of Primary Innate Immune Signaling Pathways
Authors: Hyun Jinhee , Ramos Juan Carlos , Toomey Ngoc , Balachandran Siddharth , Lavorgna Alfonso , Harhaj Edward , Barber Glen N. 
Published: February 2015

ABSTRACT
Human T-cell lymphotropic virus type I (HTLV-1) is an oncogenic retrovirus considered to be the etiological agent of adult T-cell leukemia (ATL). The viral transactivator Tax is regarded as the oncoprotein responsible for contributing toward the transformation process. Here, we demonstrate that Tax potently inhibits the activity of DEx(D/H) box helicases RIG-I and MDA5 as well as Toll-dependent TIR-domain-containing adapter-inducing interferon-β (TRIF), which function as cellular sensors or mediators of viral RNA and facilitate innate immune responses, including the production of type I IFN. Tax manifested this function by binding to the RIP homotypic interaction motif (RHIM) domains of TRIF and RIP1 to disrupt interferon regulatory factor 7 (IRF7) activity, a critical type I IFN transcription factor. These data provide further mechanistic insight into HTLV-1-mediated subversion of cellular host defense responses, which may help explain HTLV-1-related pathogenesis and oncogenesis.

IMPORTANCE
It is predicted that up to 15% of all human cancers may involve virus infection. For example, human T-cell lymphotropic virus type 1 (HTLV-1) has been reported to infect up to 25 million people worldwide and is the causative agent of adult T-cell leukemia (ATL). We show here that HTLV-1 may be able to successfully infect the T cells and remain latent due to the virally encoded product Tax inhibiting a key host defense pathway. Understanding the mechanisms by which Tax subverts the immune system may lead to the development of a therapeutic treatment for HTLV-1-mediated disease.
A Basic Cluster in the N Terminus of Yellow Fever Virus NS2A Contributes to Infectious Particle Production
Authors: Voßmann Stephanie , Wieseler Janett , Kerber Romy , Kümmerer Beate Mareike 
Published: February 2015

ABSTRACT
The flavivirus NS2A protein is involved in the assembly of infectious particles. To further understand its role in this process, a charged-to-alanine scanning analysis was performed on NS2A encoded by an infectious cDNA clone of yellow fever virus (YFV). Fifteen mutants containing single, double, or triple charged-to-alanine changes were tested. Five of them did not produce infectious particles, whereas efficient RNA replication was detectable for two of the five NS2A mutants (R22A-K23A-R24A and R99A-E100A-R101A mutants). Prolonged cultivation of transfected cells resulted in the recovery of pseudorevertants. Besides suppressor mutants in NS2A, a compensating second-site mutation in NS3 (D343G) arose for the NS2A R22A-K23A-R24A mutant. We found this NS3 mutation previously to be suppressive for the NS2Aα cleavage site Q189S mutant, also deficient in virion assembly. In this study, the subsequently suggested interaction between NS2A and NS3 was proven by coimmunoprecipitation analyses. Using selectively permeabilized cells, we could demonstrate that the regions encompassing R22A-K23A-R24A and Q189S in NS2A are localized to the cytoplasm, where NS3 is also known to reside. However, the defect in particle production observed for the NS2A R22A-K23A-R24A and Q189S mutants was not due to a defect in physical interaction between NS2A and NS3, as the NS2A mutations did not interrupt NS3 interaction. In fact, a region just upstream of R22-K23-R24 was mapped to be critical for NS2A-NS3 interaction. Taken together, these data support a complex interplay between YFV NS2A and NS3 in virion assembly and identify a basic cluster in the NS2A N terminus to be critical in this process.

IMPORTANCE
Despite an available vaccine, yellow fever remains endemic in tropical areas of South America and Africa. To control the disease, antiviral drugs are required, and an understanding of the determinants of virion assembly is central to their development. In this study, we identified a basic cluster of amino acids in the N terminus of YFV NS2A which inhibited virion assembly upon mutation. The defect was rescued by a spontaneously occurring mutation in NS3. Our study proves an interaction between NS2A and NS3, which, remarkably, was maintained for the NS2A mutant in the presence and absence of the NS3 mutation. This suggests a role for other viral and/or cellular proteins in virion assembly. Residues important for YFV virion production reported here only partially coincided with those reported for other flaviviruses, suggesting that the determinants for particle production are virus specific. Reconstruction of a YFV encoding tagged NS2A paves the way to identify further NS2A interaction partners.
Sedimentary record of glacial Lake Missoula along the Clark Fork River from deep to shallow positions in the former lakes
Authors: Smith Larry N. , Hanson Michelle A. 
Published: February 2015

Abstract
Glacial Lake Missoula was repeatedly dammed by the Purcell Trench Lobe of the Cordilleran ice sheet during the last glaciation to maximum altitudes near 4200 ft (1280 m). Studies from outside of the lake basin suggest that the lake filled and drained multiple times in the late Pleistocene. Deposits and landforms within the former glacial lake basin provide evidence for a complex lake-level history that is not well understood for this famous impoundment. At least two general lake phases are evident in the stratigraphy: an earlier phase of catastrophic drainage that was responsible for large-scale dramatic erosional and depositional features, and a later, less-catastrophic, phase responsible for the preservation of fine-grained glaciolacustrine sediments. Features of the earlier lake phase include giant gravel dunes and openwork gravel with anomalously large clasts (erratics). Deposits from the later phase are mostly low-energy glaciolacustrine sediments that record a history of lake-bottom sedimentation and repeated lake-floor exposure.
A focus of this field trip is to look at evidence for the two lake phases as well as evaluate the record of exposure surfaces, and therefore lake-level lowerings, during the second phase at multiple locations in the lake basin. One of the second phase sites is close to a highstand, full basin position in the lake (near Garden Gulch), representing a maximum water depth at this site of ~100 m, whereas others (Rail line and Ninemile) are at lower altitudes in regions that may have been under as much as 300 m of water.
Fine-grained glaciolacustrine sediments are rippled very fine sandy silt and fining-upward sequences of laminated silt and clayey silt of glaciolacustrine origin. Periglacial features, contorted bedding, desiccation, and paleosols in outcrop provide clear evidence of multiple exposure surfaces; each represent a lake-lowering event. Optically stimulated luminescence (OSL or “optical dating”) ages on quartz from the three sections (Ninemile, Rail line, and Garden Gulch) allow for preliminary correlations that suggest approximately the same phase of glacial Lake Missoula sedimentation. The exposure surfaces suggest that the glacial-lake level rose and fell at least 8–12 times to elevations above and below the sections (936–1180 m), filling to within 100 m of full pool (1280 m). Optical dating shows that this occurred after 20 ka and the last inundation of the lake before 13.5 ka. Correlation of specific exposure surfaces throughout the basin will be required to develop a lake-level history.