bluuebunny/crossref_metadata_2025_split huggingface dataset:
Siemens SGT-800 Industrial Gas Turbine Enhanced to 50 MW: Turbine Design Modifications, Validation and Operation Experience
Authors: Wang Lieke , Bahador Mehdi , Bruneflod Simon , Annerfeldt Mats , Björkman Mats , Hultmark Ingvar 
Published: November 2013

Siemens Oil & Gas introduced an enhanced SGT-800 gas turbine during 2010. The new power rating is 50.5 MW with a 38.3 % electrical efficiency (ISO) in simple cycle and the best in class combined-cycle performance of more than 55 %. The increased power and improved efficiency from the existing 47 MW rating are mainly obtained by improved compressor airfoil profiles and improved turbine aerodynamics and cooling air layout. The upgrade components in the gas turbine are interchangeable from the existing rating. The current paper is focused on the design modifications of the turbine parts and their validation and operation experience.
For the turbine section, the main design modifications include the redesigned stage 1 with better aerodynamic and cooling performance, modified stage 3 for increased outlet area, etc. However, the turbine inlet temperature is not increased compared to the existing 47 MW rating. Comprehensive validation measures have been taken to make sure that the modifications meet the design targets, at both the component level and the system level. The results from the validation tests have confirmed the turbine performance in terms of aerodynamics, cooling, life time, etc. In addition, these results have given a strong basis for future upgrade, e.g., potential cooling air saving has been identified on several areas. The first SGT-800 with 50.5 MW rating was successfully operated and tested during the spring 2010 and the expected performance figures were confirmed. Up to January 2013, the fleet of this new rating has accumulated >40 000 Equivalent Operation hours (EOH), while the fleet leader has accumulated >16 000 EOH. A planned follow up inspection was made after 10 000 EOH by using borescope for the hot section, and it showed that all the turbine parts were in good condition.
Investigation of Alternate Mistuned Turbine Blades Non-Linear Coupled by Underplatform Dampers
Authors: Tatzko S. , Panning-von Scheidt L. , Wallaschek J. , Kayser A. , Walz G. 
Published: November 2013

Freestanding turbine blades have typically low structural damping and thus require additional friction damping devices, such as underplatform dampers. The friction coupling between neighboring blades reduces response amplitude and increases resonance frequency. Along with forced response excitation large blades, especially of last stage, could be excited by fluid structural interaction (flutter). To prevent such excitation alternate mistuned blade patterns are beneficial disturbing traveling waves in the stage.
In this paper the influence of alternate mistuning is investigated with a simplified oscillator chain as well as a bladed disk assembly coupled by frictional contacts. It is pointed out that the performance of friction coupling can be improved by alternate mistuning as long as the engine order of the excitation is below quarter of the number of blades. Alternate mistuning causes a mode coupling between two nodal diameter vibration mode shapes allowing for energy transfer. The in-house developed software code DATAR is enhanced and alternate mistuning can be applied to the blades as well as to the damping elements. For validation the DATAR code was applied to an alternate mistuned last stage blade of a Siemens gas turbine and compared with available field engine measurement.
Improvement of Compressor Blade Vibrations Spectral Analysis From Tip Timing Data: Aliasing Reduction
Authors: Vercoutter A. , Lardies J. , Berthillier M. , Talon A. , Burgardt B. 
Published: November 2013

Tip-timing is a technique for measuring rotating blades vibrations in operation. Its concept exists since the early 70s but it has been more experimented in the last decade through improvements in hardware and software capabilities. It consists of a set of sensors mounted on stator casings that record blade passing times. Then, from this measurement, blade vibrations can be estimated.
Tip-timing technique presents several advantages compared to usual mean of measurement: strain gages. Indeed, installation is easier, it is non-intrusive and all the blades can be monitored.
However, resulting sampling depends on physical configuration i.e. number of sensors. In practice, as the number of sensors is limited, sampling rate is low in relation to the physical observed frequencies and do not respect the Shannon criterion. Thus, it generates important aliasing effects in spectrum, which makes the analysis difficult. In fact, such measurements aim to lead to pseudo-blind analysis, especially for asynchronous vibrations, when there is no hypothesis of underneath structural model.
This main problem of aliasing is partially softened by using a minimum variance spectral estimator that iteratively reduces non-physical content in spectrum, but pseudo-blind analysis remains complicated.
This paper presents a comparison of several methods based on different multisampling averaging concepts for reducing aliasing. Multisampling averaging consists in averaging spectrums from different sampling patterns of the same original signal, so that only stable physical content remains in the final spectrum. This study is presented on different industrial test cases of blade vibrations.
Template‐based automatic breast segmentation on MRI by excluding the chest region
Authors: Lin Muqing , Chen Jeon‐Hor , Wang Xiaoyong , Chan Siwa , Chen Siping , Su Min‐Ying 
Published: November 2013

Purpose:Methods for quantification of breast density on MRI using semiautomatic approaches are commonly used. In this study, the authors report on a fully automatic chest template‐based method.Methods:Nonfat‐suppressed breast MR images from 31 healthy women were analyzed. Among them, one case was randomly selected and used as the template, and the remaining 30 cases were used for testing. Unlike most model‐based breast segmentation methods that use the breast region as the template, the chest body region on a middle slice was used as the template. Within the chest template, three body landmarks (thoracic spine and bilateral boundary of the pectoral muscle) were identified for performing the initial V‐shape cut to determine the posterior lateral boundary of the breast. The chest template was mapped to each subjectˈs image space to obtain a subject‐specific chest model for exclusion. On the remaining image, the chest wall muscle was identified and excluded to obtain clean breast segmentation. The chest and muscle boundaries determined on the middle slice were used as the reference for the segmentation of adjacent slices, and the process continued superiorly and inferiorly until all 3D slices were segmented. The segmentation results were evaluated by an experienced radiologist to mark voxels that were wrongly included or excluded for error analysis.Results:The breast volumes measured by the proposed algorithm were very close to the radiologistˈs corrected volumes, showing a % difference ranging from 0.01% to 3.04% in 30 tested subjects with a mean of 0.86% ± 0.72%. The total error was calculated by adding the inclusion and the exclusion errors (so they did not cancel each other out), which ranged from 0.05% to 6.75% with a mean of 3.05% ± 1.93%. The fibroglandular tissue segmented within the breast region determined by the algorithm and the radiologist were also very close, showing a % difference ranging from 0.02% to 2.52% with a mean of 1.03% ± 1.03%. The total error by adding the inclusion and exclusion errors ranged from 0.16% to 11.8%, with a mean of 2.89% ± 2.55%.Conclusions:The automatic chest template‐based breast MRI segmentation method worked well for cases with different body and breast shapes and different density patterns. Compared to the radiologist‐established truth, the mean difference in segmented breast volume was approximately 1%, and the total error by considering the additive inclusion and exclusion errors was approximately 3%. This method may provide a reliable tool for MRI‐based segmentation of breast density.
Inter‐slice bidirectional registration‐based segmentation of the prostate gland in MR and CT image sequences
Authors: Khalvati Farzad , Salmanpour Aryan , Rahnamayan Shahryar , Rodrigues George , Tizhoosh Hamid R. 
Published: November 2013

Purpose:Accurate segmentation and volume estimation of the prostate gland in magnetic resonance (MR) and computed tomography (CT) images are necessary steps in diagnosis, treatment, and monitoring of prostate cancer. This paper presents an algorithm for the prostate gland volume estimation based on the semiautomated segmentation of individual slices in T2‐weighted MR and CT image sequences.Methods:The proposedInter‐Slice Bidirectional Registration‐based Segmentation (iBRS) algorithm relies on interslice image registration of volume data to segment the prostate gland without the use of an anatomical atlas. It requires the user to mark only three slices in a given volume dataset, i.e., the first, middle, and last slices. Next, the proposed algorithm uses a registration algorithm to autosegment the remaining slices. We conducted comprehensive experiments to measure the performance of the proposed algorithm using three registration methods (i.e., rigid, affine, and nonrigid techniques).Results:The results with the proposed technique were compared with manual marking using prostate MR and CT images from 117 patients. Manual marking was performed by an expert user for all 117 patients. The median accuracies for individual slices measured using the Dice similarity coefficient (DSC) were 92% and 91% for MR and CT images, respectively. The iBRS algorithm was also evaluated regarding user variability, which confirmed that the algorithm was robust to interuser variability when marking the prostate gland.Conclusions:The proposed algorithm exploits the interslice data redundancy of the images in a volume dataset of MR and CT images and eliminates the need for an atlas, minimizing the computational cost while producing highly accurate results which are robust to interuser variability.
Blocking eIF5A Modification in Cervical Cancer Cells Alters the Expression of Cancer-Related Genes and Suppresses Cell Proliferation
Authors: Mémin Elisabeth , Hoque Mainul , Jain Mohit R. , Heller Debra S. , Li Hong , Cracchiolo Bernadette , Hanauske-Abel Hartmut M. , Pe'ery Tsafi , Mathews Michael B. 
Published: November 2013

Abstract
Cancer etiology is influenced by alterations in protein synthesis that are not fully understood. In this study, we took a novel approach to investigate the role of the eukaryotic translation initiation factor eIF5A in human cervical cancers, where it is widely overexpressed. eIF5A contains the distinctive amino acid hypusine, which is formed by a posttranslational modification event requiring deoxyhypusine hydroxylase (DOHH), an enzyme that can be inhibited by the drugs ciclopirox and deferiprone. We found that proliferation of cervical cancer cells can be blocked by DOHH inhibition with either of these pharmacologic agents, as well as by RNA interference–mediated silencing of eIF5A, DOHH, or another enzyme in the hypusine pathway. Proteomic and RNA analyses in HeLa cervical cancer cells identified two groups of proteins in addition to eIF5A that were coordinately affected by ciclopirox and deferiprone. Group 1 proteins (Hsp27, NM23, and DJ-1) were downregulated at the translational level, whereas group 2 proteins (TrpRS and PRDX2) were upregulated at the mRNA level. Further investigations confirmed that eIF5A and DOHH are required for Hsp27 expression in cervical cancer cells and for regulation of its key target IκB and hence NF-κB. Our results argue that mature eIF5A controls a translational network of cancer-driving genes, termed the eIF5A regulon, at the levels of mRNA abundance and translation. In coordinating cell proliferation, the eIF5A regulon can be modulated by drugs such as ciclopirox or deferiprone, which might be repositioned to control cancer cell growth. Cancer Res; 74(2); 552–62. ©2013 AACR.
Psychological Distress after a Positive Fecal Occult Blood Test Result among Members of an Integrated Healthcare Delivery System
Authors: Laing Sharon S. , Bogart Andy , Chubak Jessica , Fuller Sharon , Green Beverly B. 
Published: November 2013

Abstract
Background: Colorectal cancer screening (CRCS) reduces morbidity and mortality; however, the positive benefits might be partially offset by long-term distress following positive screening results. We examined relationships among colorectal cancer–specific worry and situational anxiety after positive fecal occult blood tests [FOBT (+)] compared with receipt of negative results.
Methods: Of note, 2,260 eligible members of Group Health, an integrated healthcare delivery system, completed baseline surveys and received FOBT screening kits, with 1,467 members returning the kits. We matched FOBT (+) patients (n = 55) 1:2 on age and sex with FOBT (−) respondents (n = 110). Both groups completed follow-up surveys at 7 to 14 days and 4 months after screening. We assessed situational anxiety (State-Trait Anxiety Inventory, STAI), colorectal cancer worry frequency, and mood disturbance.
Results: Mean age was 59 years, and majority were women (62%) and White (89%). After adjusting for age, sex, and baseline worry, at 7 to 14 days after screening, the FOBT (+) group was 3.82 [95% confidence interval (CI), 1.09–13.43] times more likely to report colorectal cancer–related mood disturbances and significantly higher mean STAI scores than the FOBT (−) group (mean = 38.8 vs. 30.9; P = 0.007). At 4-month posttest, mood disturbances and situational anxiety seemed to drop to baseline levels for FOBT (+). No colon cancer worry frequency was observed.
Conclusions: FOBT (+) results are associated with short-term situational anxiety and colorectal cancer–specific mood disturbances.
Impact: Distress from FOBT (+) results declined to near-baseline levels by 4 months. Additional studies are needed to clarify the relationship between long-term distress and follow-up colonoscopy. Cancer Epidemiol Biomarkers Prev; 23(1); 154–9. ©2013 AACR.
Plasma MicroRNA Are Disease Response Biomarkers in Classical Hodgkin Lymphoma
Authors: Jones Kimberley , Nourse Jamie P. , Keane Colm , Bhatnagar Atul , Gandhi Maher K. 
Published: November 2013

Abstract
Purpose: Although microRNAs (miRNA) show potential as diagnostic biomarkers in cancer, their role as circulating cell-free disease response biomarkers remains unknown. Candidate circulating miRNA biomarkers for classical Hodgkin lymphoma (cHL) might arise from Hodgkin–Reed–Sternberg (HRS) cells and/or nonmalignant tumor-infiltrating cells. HRS cells are sparse within the diseased node, embedded within a benign microenvironment, the composition of which is distinct from that seen in healthy lymph nodes.
Experimental Design: Microarray profiling of more than 1,000 human miRNAs in 14 cHL primary tissues and eight healthy lymph nodes revealed a number of new disease node–associated miRNAs, including miR-494 and miR-1973. Using quantitative real-time PCR (qRT-PCR), we tested the utility of these, as well as previously identified disease node–associated plasma miRNAs (including miR-21 and miR-155), as disease response biomarkers in a prospective cohort of 42 patients with cHL. Blood samples were taken in conjunction with radiologic imaging at fixed time points before, during, and after therapy. Absolute quantification was used so as to facilitate implementation in diagnostic laboratories.
Results: Levels of miR-494, miR-1973, and miR-21 were higher in patients than control (n = 20) plasma (P = 0.004, P = 0.007, and P &lt; 0.0001, respectively). MiR-494 and miR-21 associated with Hasenclever scores ≥3. Strikingly, all three miRNAs returned to normal at remission (P = 0.0006, P = 0.0002, and P &lt; 0.0001 respectively). However, only miR-494 and miR-1973 reflected interim therapy response with reduction being more pronounced in patients achieving complete versus partial responses (P = 0.043 and P = 0.0012, respectively).
Conclusion: Our results demonstrate that in patients with cHL, circulating cell-free miRNAs can reflect disease response once therapy has commenced. Clin Cancer Res; 20(1); 253–64. ©2013 AACR.
Response to MLN8237 in Pancreatic Cancer Is Not Dependent on RalA Phosphorylation
Authors: Neel Nicole F. , Stratford Jeran K. , Shinde Vaishali , Ecsedy Jeffrey A. , Martin Timothy D. , Der Channing J. , Yeh Jen Jen 
Published: November 2013

Abstract
The high prevalence of KRAS mutations and importance of the RalGEF–Ral pathway downstream of activated K-ras in pancreatic ductal adenocarcinoma (PDAC) emphasize the importance of identifying novel methods by which to therapeutically target these pathways. It was recently demonstrated that phosphorylation of RalA S194 by Aurora A kinase (AAK) is critical for PDAC tumorigenesis. We sought to evaluate the AAK-selective inhibitor MLN8237 as a potential indirect anti-RalA–targeted therapy for PDAC. We used a site-specific phospho-S194 RalA antibody and determined that RalA S194 phosphorylation levels were elevated in a subset of PDAC cell lines and human tumors relative to unmatched normal controls. Effects of MLN8237 on anchorage-independent growth in PDAC cell lines and growth of patient-derived xenografts (PDX) were variable, with a subset of cell lines and PDX showing sensitivity. Surprisingly, RalA S194 phosphorylation levels in PDAC cell lines or PDX tumors did not correlate with MLN8237 responsiveness. However, we identified Ki67 as a possible early predictive biomarker for response to MLN8237 in PDAC. These results indicate that MLN8237 treatment may be effective for a subset of patients with PDAC independent of RalA S194 phosphorylation. Ki67 may be an effective pharmacodynamic biomarker to identify response early in the course of treatment. Mol Cancer Ther; 13(1); 122–33. ©2013 AACR.
High Prevalence of Hypertension Among Collegiate Football Athletes
Authors: Karpinos Ashley Rowatt , Roumie Christianne L. , Nian Hui , Diamond Alex B. , Rothman Russell L. 
Published: November 2013

Background—
The prevalence of hypertension among collegiate football athletes is not well described.

Methods and Results—

A retrospective cohort of all male athletes who participated in varsity athletics at a National Collegiate Athletic Association Division I university between 1999 and 2012 was examined through chart review. Mandatory annual preparticipation physical examinations included blood pressure, body mass index, medication use, and supplement use. Prevalence of hypertension was compared between football and nonfootball athletes. A mixed-effects linear regression model examined change in blood pressure over time. Six hundred thirty-six collegiate athletes, including 323 football players, were identified. In the initial year of athletic participation, 19.2% of football athletes had hypertension and 61.9% had prehypertension. The prevalence of hypertension was higher among football athletes than in nonfootball athletes in their initial (19.2% versus 7.0%;
P
<0.001) and final (19.2% versus 10.2%;
P
=0.001) years of athletic participation. In adjusted analyses, the odds of hypertension were higher among football athletes in the initial year (adjusted odds ratio, 2.28; 95% confidence interval, 1.21–4.30) but not in the final year (adjusted odds ratio, 1.25; 95% confidence interval, 0.69–2.28). Over the course of their collegiate career, football athletes had an annual decrease in systolic blood pressure (−0.82 mm Hg;
P
=0.002), whereas nonfootball athletes did not (0.18 mm Hg;
P
=0.58).

Conclusions—
Hypertension and prehypertension were common among collegiate football athletes, and football athletes were more likely to have hypertension compared with male nonfootball athletes. This presents a potential cardiovascular risk in a young population of athletes. Strategies for increasing awareness, prevention, and treatment are needed.
Influence of Cardiac Surgeon Report Cards on Patient Referral by Cardiologists in New York State After 20 Years of Public Reporting
Authors: Brown David L. , Epstein Arnold M. , Schneider Eric C. 
Published: November 2013

Background—
Report cards of risk-adjusted mortality rates of individual cardiac surgeons have been publicly available in New York State since 1991. A survey of New York cardiologists in 1996 found that these report cards had little effect on their referral recommendations to cardiac surgeons. It is unknown whether the influence of report cards on referral behavior has changed over time.

Methods and Results—

We surveyed cardiologists in New York State in 2011 to determine their awareness of cardiac surgeon report cards, their use of the report card in formulating judgments about the quality of cardiac surgeons and selecting cardiac surgeons for referral of patients, and discussion of the report with patients in need of cardiac surgery. The relation between demographic (age, sex) and professional (teaching, board certification, faculty appointment, general cardiology practice, and hospital employee) characteristics and the influence of report cards on referral decisions was assessed using χ
2
for categorical variables and
t
test for continuous variables. Multivariable logistic regression models were created to determine the independent association of any variable with
P
<0.1 on univariate analysis. Almost all (94%) cardiologists were aware of report cards of cardiac surgeons. The influence of the report cards on cardiologists’ referral decisions was limited, with 25% of cardiologists reporting a moderate or substantial influence on referral decisions. The report card was not discussed with any patients by 71% of cardiologists. The mean age of cardiologists reporting moderate or substantial influence of report cards was 58 years compared with 54 years for those who reported no/little influence (
P
=0.012). Fewer cardiologists who reported moderate or substantial influence were board certified (91% versus 99%;
P
=0.003). On multivariate analysis, general cardiology practice and employment by a hospital were independently associated with greater report card influence (odds ratio, 1.03; 95% confidence interval, 1.01–1.05;
P
=0.13).

Conclusions—
After 20 years of public reporting and almost universal awareness of cardiac surgeon report cards, in 2011, cardiologists in New York State made little use of this information and rarely discussed it with patients at the time of referral for cardiac surgery.