bluuebunny/crossref_metadata_2025 huggingface dataset:
The XIPHOS diffraction facility for extreme sample conditions
Authors: Probert Michael R. , Robertson Craig M. , Coome Jonathan A. , Howard Judith A. K. , Michell Brian C. , Goeta Andrés E.
Published: October 2010

XIPHOS has been developed to expand home laboratory facilities closer to those found at central facilities, offering extremes of sample environment and flux densities far greater than standard laboratory sources. The system has a minimum operating temperature of 1.9 K, and has a direct-drive molybdenum rotating-anode generator coupled with the latest multilayer optics. XIPHOS has been specifically designed to accommodate various sample environments and is now operational. Furthermore, it has been calibrated with structural phase transitions from 14 to 148 K. Results are also presented from a full low-temperature data collection ofm-nitroaniline to demonstrate the quality of results attainable from XIPHOS.
Characterization of the parameters relating adjacent grains using transmission electron microscopy
Authors: Jeong H. W. , Seo S. M. , Hong H. U. , Yoo Y. S.
Published: October 2010

A simple technique is presented for characterizing parameters such as the misorientation angle and the axis of rotation between two adjacent grains using transmission electron microscopy (TEM), without the need for an image of the Kikuchi pattern. The technique described makes use of the orthogonal relationship between the tilt axes used in TEM and the axes of the cubic crystal. The relationship was established using the well known triangulation method, in which the direction of the crystal parallel to the beam direction is determined from the measured tilt angles of the three zone axes. The error in measuring the tilt angles of the three zone axes can be evaluated by comparing the measured and crystallographic angles. The angle of deviation from the coincident site lattice (CSL) that results from the measurement error could be reduced by establishing the modified orthogonal relationship between the tilt and crystal axes. The use of this method could provide accurate measurement in real time for indexing a CSL boundary using TEM.
Vitamin E biosynthesis: functional characterization of the monocot homogentisate geranylgeranyl transferase
Authors: Yang Wenyu , Cahoon Rebecca E. , Hunter Sarah C. , Zhang Chunyu , Han Jixiang , Borgschulte Trissa , Cahoon Edgar B.
Published: October 2010

The biosynthesis of the tocotrienol and tocopherol forms of vitamin E is initiated by prenylation of homogentisate. Geranylgeranyl diphosphate (GGDP) is the prenyl donor for tocotrienol synthesis, whereas phytyl diphosphate (PDP) is the prenyl donor for tocopherol synthesis. We have previously shown that tocotrienol synthesis is initiated in monocot seeds by homogentisate geranylgeranyl transferase (HGGT). This enzyme is related to homogentisate phytyltransferase (HPT), which catalyzes the prenylation step in tocopherol synthesis. Here we show that monocot HGGT is localized in the plastid and expressed primarily in seed endosperm. Despite the close structural relationship of monocot HGGT and HPT, these enzymes were found to have distinct substrate specificities. Barley (Hordeum vulgare cv. Morex) HGGT expressed in insect cells was six times more active with GGDP than with PDP, whereas the Arabidopsis HPT was nine times more active with PDP than with GGDP. However, only small differences were detected in the apparent Km values of barley HGGT for GGDP and PDP. Consistent with its in vitro substrate properties, barley HGGT generated a mixture of tocotrienols and tocopherols when expressed in the vitamin E‐null vte2‐1 mutant lacking a functional HPT. Relative levels of tocotrienols and tocopherols produced in vte2‐1 differed between organs and growth stages, reflective of the composition of plastidic pools of GGDP and PDP. In addition, HGGT was able to functionally substitute for HPT to rescue vte2‐1‐associated phenotypes, including reduced seed viability and increased fatty acid oxidation of seed lipids. Overall, we show that monocot HGGT is biochemically distinct from HPT, but can replace HPT in important vitamin E‐related physiological processes.
Somatosensory amplification as a possible source of subjective symptoms behind modern health worries
Authors: KÖTELES FERENC , SZEMERSZKY RENÁTA , FREYLER ANETT , BÁRDOS GYÖRGY
Published: October 2010

Köteles, F., Szemerszky, R., Freyler, A. & Bárdos, G. (2011). Somatosensory amplification as a possible source of subjective symptoms behind modern health worries. Scandinavian Journal of Psychology 52, 174–178.

The theoretically hypothesized connection between modern health worries (MHWs) and somatosensory amplification (SSA), as well as the factor structure of the Hungarian version of the MHW scale were investigated in a cross‐sectional questionnaire study. A total of 163 university students (mean age = 21.3± 2.70 yrs; 44.2% male) and 145 patients (mean age = 49.4±17.51 yrs; 31.7% male) visiting their general practitioners (GPs) completed questionnaires assessing MHWs, SSA, subjective somatic symptoms (PHQ‐15), and trait anxiety (STAI‐T). The previously described four‐factor structure of the MHW scale was confirmed using confirmatory factor analysis (CFA). In the linear regression analysis, participants’ age and SSA scores were positively related to MHWs even after controlling for gender, anxiety, and subjective somatic symptom scores. The conclusions are that: MHWs are indicators of cognitive, behavioral and social level of sensitization for health‐related concerns; SSA can provide the somatic background process for generation and/or misattribution of subjective somatic symptoms; better understanding of the cognitive‐emotional background of MHWs could help to determine possible interventions.
Coverage and Preventive Screening
Authors: Meeker Daniella , Joyce Geoffrey F. , Malkin Jesse , Teutsch Steven M. , Haddix Anne C. , Goldman Dana P.
Published: October 2010

Context. Preventive care has been shown as a high‐value health care service. Many employers now offer expanded coverage of preventive care to encourage utilization.

Objective. To determine whether expanding coverage is an effective means to encourage utilization.

Design. Comparison of screening rates before and after introduction of deductible‐free coverage.

Setting. People insured through large corporations between 2002 and 2006.

Patients or Other Participants. Preferred Provider Organization (PPO) enrollees from an employer introducing deductible‐free coverage, and a control group enrolled in a PPO from a second employer with no policy change.

Main Outcome Measures. Adjusted probability of endoscopy, fecal occult blood test (FOBT), lipid screens, mammography, and Papanicolaou (pap) smears.

Intervention. Introduction of first‐dollar coverage (FDC) of preventive services in 2003.

Results. After adjusting for demographics and secular trends, there were between 23 and 78 additional uses per 1,000 eligible patients of covered preventive screens (lipid screens, pap smears, mammograms, and FOBT), with no significant changes in the control group or in a service without FDC (endoscopy).

Conclusions. FDC improves utilization modestly among healthy individuals, particularly those in lower deductible plans. Compliance with guidelines can be encouraged by lowering out‐of‐pocket costs, but patients' predisposing characteristics merit attention.
Incremental Cost of Postacute Care in Nursing Homes
Authors: Spector William D. , Limcangco Maria Rhona , Ladd Heather , Mukamel Dana
Published: October 2010

Objectives. To determine whether the case mix index (CMI) based on the 53‐Resource Utilization Groups (RUGs) captures all the cross‐sectional variation in nursing home (NH) costs or whether NHs that have a higher percent of Medicare skilled care days (%SKILLED) have additional costs.

Data and Sample. Nine hundred and eighty‐eight NHs in California in 2005. Data are from Medicaid cost reports, the Minimum Data Set, and the Economic Census.

Research Design. We estimate hybrid cost functions, which include in addition to outputs, case mix, ownership, wages, and %SKILLED. Two‐stage least‐square (2SLS) analysis was used to deal with the potential endogeneity of %SKILLED and CMI.

Results. On average 11 percent of NHs days were due to skilled care. Based on the 2SLS model, %SKILLED is associated with costs even when controlling for CMI. The marginal cost of a one percentage point increase in %SKILLED is estimated at U.S.$70,474 or about 1.2 percent of annual costs for the average cost facility. Subanalyses show that the increase in costs is mainly due to additional expenses for nontherapy ancillaries and rehabilitation.

Conclusion. The 53‐RUGs case mix does not account completely for all the variation in actual costs of care for postacute patients in NHs.
Effects of Competition on the Cost and Quality of Inpatient Rehabilitation Care under Prospective Payment
Authors: Colla Carrie Hoverman , Escarce José J. , Buntin Melinda Beeuwkes , Sood Neeraj
Published: October 2010

Objective. To determine the effect of competition in postacute care (PAC) markets on resource intensity and outcomes of care in inpatient rehabilitation facilities (IRFs) after prospective payment was implemented.

Data Sources. Medicare claims, Provider of Services file, Enrollment file, Area Resource file, Minimum Data Set.

Study Design. We created an exogenous measure of competition based on patient travel distances and used instrumental variables models to estimate the effect of competition on inpatient rehabilitation costs, length of stay, and death or institutionalization.

Data Extraction Methods. A file was constructed linking data for Medicare patients discharged from acute care between 2002 and 2003 and admitted to an IRF with a diagnosis of hip fracture or stroke.

Principal Findings. Competition had different effects on treatment intensity and outcomes for hip fracture and stroke patients. In the treatment of hip fracture, competition increased costs and length of stay, while increasing rates of death or institutionalization. In the treatment of stroke, competition decreased costs and length of stay and produced inferior outcomes.

Conclusions. The effects of competition in PAC markets may vary by condition. It is important to study the effects of competition by diagnostic condition and to study the effects across populations that vary in severity. Our finding that higher competition under prospective payment led to worse IRF outcomes raises concerns and calls for additional research.
Impact of High‐Deductible Health Plans on Health Care Utilization and Costs
Authors: Waters Teresa M. , Chang Cyril F. , Cecil William T. , Kasteridis Panagiotis , Mirvis David
Published: October 2010

Background. High‐deductible health plans (HDHPs) are of high interest to employers, policy makers, and insurers because of potential benefits and risks of this fundamentally new coverage model.

Objective. To investigate the impact of HDHPs on health care utilization and costs in a heterogeneous group of enrollees from a variety of individual and employer‐based health plans.

Data. Claims and member data from a major insurer and zip code‐level census data.

Study Design. Retrospective difference‐in‐differences analyses were used to examine the impact of HDHP plans. This analytical approach compared changes in utilization and expenditures over time (2007 versus 2005) across the two comparison groups (HDHP switchers versus matched PPO controls).

Results. In two‐part models, HDHP enrollment was associated with reduced emergency room use, increases in prescription medication use, and no change in overall outpatient expenditures. The impact of HDHPs on utilization differed by subgroup. Chronically ill enrollees and those who clearly had a choice of plans were more likely to increase utilization in specific categories after switching to an HDHP plan.

Conclusions. Whether HDHPs are associated with lower costs is far from settled. Various subgroups of enrollees may choose HDHPs for different reasons and react differently to plan incentives.
Counting Uninsurance and Means‐Tested Coverage in the American Community Survey: A Comparison to the Current Population Survey
Authors: Boudreaux Michel , Ziegenfuss Jeanette Y. , Graven Peter , Davern Michael , Blewett Lynn A.
Published: October 2010

Objective. To compare health insurance coverage estimates from the American Community Survey (ACS) to the Current Population Survey (CPS‐ASEC).

Data Sources/Study Setting. The 2008 ACS and CPS‐ASEC, 2009.

Study Design. We compare age‐specific national rates for all coverage types and state‐level rates of uninsurance and means‐tested coverage. We assess differences using t‐tests and p‐values, which are reported at <.05, <.01, and <.001. An F‐test determines whether differences significantly varied by state.

Principal Findings. Despite substantial design differences, we find only modest differences in coverage estimates between the surveys. National direct purchase and state‐level means‐tested coverage levels for children show the largest differences.

Conclusions. We suggest that the ACS is well poised to become a useful tool to health services researchers and policy analysts, but that further study is needed to identify sources of error and to quantify its bias.
The Residential History File: Studying Nursing Home Residents' Long‐Term Care Histories*
Authors: Intrator Orna , Hiris Jeffrey , Berg Katherine , Miller Susan C. , Mor Vince
Published: October 2010

Objective. To construct a data tool, the Residential History File (RHF), that summarizes information from Medicare claims and nursing home (NH) Minimum Data Set (MDS) assessments to track people through health care locations, including non‐Medicare‐paid NH stays.

Data Sources. Online Survey of Certification and Reporting (OSCAR) data for 202 free‐standing NHs, Medicare Denominator, claims (parts A and B), and MDS assessments for 60,984 people who were present in one of these NHs in 2006.

Methods. The algorithm creating the RHF is outlined and the RHF for the study data are used to describe place of death. The identification of residents in NHs is compared with the reports in OSCAR and part B claims.

Principal Findings. The RHF correctly identified 84.8 percent of part B claims with place‐of‐service in NH, and it identified 18.3 less residents on average than reported in the OSCAR on the day of the survey. The RHF indicated that 17.5 percent non‐Medicare NH decedents were transferred to the hospital to die versus 45.6 percent skilled nursing facility decedents.

Conclusions. The population‐based design of the RHF makes it possible to conduct policy‐relevant research to examine the variation in the rate and type of health care transitions across the United States.
Impedance Changes on Defibrillation Coils after Atrial Fibrillation Ablation: Lead Damage or Electromechanical Interference?
Authors: VANGA SUBBA REDDY , BOMMANA SUDHARANI , KROLL MARK , LAKKIREDDY DHANUNJAYA
Published: October 2010

Fluctuation of impedance on defibrillator leads is highly suggestive of lead failure. A drop in impedance is associated with insulation defects while high impedance is suggestive of lead fracture. In this case report, we described a patient where electromagnetic interference from radiofrequency ablation near the site of superior vena cava coil caused the sensed impedance to fluctuate without uneventful outcomes and we discussed the possible mechanism. Both electromagnetic interference and defibrillator lead insulation defect can result in low threshold and inappropriate shocks. Sometimes electromagnetic interference may result in physical damage of the implanted system and may result in subsequent fluctuations in impedance. Awareness of electromagnetic interference that can cause fluctuating impedance without structural damage can help in making appropriate diagnosis and may avoid unnecessary procedures. (PACE 2012; 35:e163–e166)
Identification of a Conduction Gap of the Mitral Isthmus by Using a Novel High‐Density Mapping Catheter
Authors: MATSUO SEIICHIRO , YAMANE TEIICHI , HIOKI MIKA , TANIGAWA SHIN‐ICHI , TOKUTAKE KEN‐ICHI , ITO KEIICHI , NARUI RYOHSUKE , NAKANE TOKIKO , TOKUDA MICHIFUMI , YAMASHITA SEIGO , INADA KEIICHI , DATE TARO , SUGIMOTO KEN‐ICHI , YOSHIMURA MICHIHIRO
Published: October 2010

Peri‐mitral atrial flutter, which is a type of macroreentrant atrial tachycardia circulating around the mitral annulus, was terminated with the guidance of the high‐density mapping catheter. A 72‐year‐old woman with atrial fibrillation and atrial tachycardia presented with symptoms of congestive heart failure. The recurrent peri‐mitral atrial flutter following the initial catheter ablation for atrial tachycardia and atrial fibrillation was terminated by radiofrequency application on the gap that was identified using a novel high‐density mapping catheter. (PACE 2010; 1–4)
Flecainide‐Associated Bradycardia‐Dependent Torsade de Pointes: Another Potential Mechanism of Proarrhythmia
Authors: KIM HAN SANG , PAK HUI‐NAM , PARK JONG SEOUNG , KIM SUNG SOON
Published: October 2010

Although flecainide has a risk of proarrhythmia in patients with structural heart disease, its mechanism has been mainly ascribed to use‐dependency and a rapid ventricular response to organized atrial tachyarrhythmias or to ventricular tachycardia. We present a patient who experienced recurrent syncope due to bradycardia‐dependent torsade de pointes (TdP) associated with flecainide‐related bradycardia and QT prolongation. Bradycardia‐dependent TdP with QT prolongation can be considered as one of mechanisms of flecainide‐induced proarrhythmia.
Early Diagnosis and Rescue Pericardiocentesis for Acute Cardiac Tamponade during Radiofrequency Ablation for Arrhythmias. Is Fluoroscopy Enough?
Authors: HUANG XIN‐MIAO , HU JIAN‐QIANG , ZHOU FEI , QIN YONG‐WEN , CAO JIANG , ZHOU BING‐YAN , ZHAO XIAN‐XIAN , ZHENG XING
Published: October 2010

Background: With the number of complex catheter ablation procedures increasing, procedure‐related acute cardiac tamponade is encountered more frequently in the cardiac catheterization laboratory. Survival depends on prompt recognition and rescue pericardiocentesis.

Objective: The aim of this report was to validate fluoroscopic heart silhouette characteristics associated with cardiac tamponade as a diagnostic method, and evaluate the safety and effectiveness of fluoroscopy‐guided pericardiocentesis during catheter ablation.

Methods: All cases of acute cardiac tamponade that occurred in the cardiac catheterization laboratory during radiofrequency catheter ablation from March 2004 to November 2009 were reviewed retrospectively.

Results: Of 1,832 catheter ablation procedures performed during a 5‐year period, 10 (0.55%) were complicated by cardiac tamponade. Fluoroscopic examination confirmed the diagnosis in all 10 patients and demonstrated effusions before hypotension in four patients. All patients were stabilized by fluoroscopy‐guided pericardiocentesis with placement of an indwelling catheter and autologous transfusion. The time interval between recognition of cardiac tamponade and completion of pericardiocentesis was 6.0 ± 1.8 minutes (range 3–9 minutes). The mean aspirated blood volume was 437 mL (range 110–1,400 mL), and the mean autotransfused blood volume was 425 mL (range 100–1,384 mL). Surgical repair of the cardiac perforation was needed in one patient. No procedure‐related death occurred.

Conclusion: A reduction in the excursion of cardiac silhouette on fluoroscopy is an early diagnostic sign of cardiac tamponade during radiofrequency ablation. Fluoroscopy‐guided pericardiocentesis is a safe and effective management strategy for cardiac tamponade developed in the cardiac catheterization laboratory. (PACE 2011; 9–14)
Advanced Image Fusion to Overlay Coronary Sinus Anatomy with Real‐Time Fluoroscopy to Facilitate Left Ventricular Lead Implantation in CRT
Authors: DUCKETT SIMON G. , GINKS MATTHEW R , KNOWLES BENJAMIN R. , MA YINGLIANG , SHETTY ANOOP , BOSTOCK JULIAN , COOKLIN MICHAEL , GILL JAS S. , CARR‐WHITE GERRY S. , RAZAVI REZA , SCHAEFFTER TOBIAS , RHODE KAWAL S. , RINALDI C. ALDO
Published: October 2010

Background: Failure rate for left ventricular (LV) lead implantation in cardiac resynchronization therapy (CRT) is up to 12%. The use of segmentation tools, advanced image registration software, and high‐fidelity images from computerized tomography (CT) and cardiac magnetic resonance (CMR) of the coronary sinus (CS) can guide LV lead implantation. We evaluated the feasibility of advanced image registration onto live fluoroscopic images to allow successful LV lead placement.

Methods: Twelve patients (11 male, 59 ± 16.8 years) undergoing CRT had three‐dimensional (3D) whole‐heart imaging (six CT, six CMR). Eight patients had at least one previously failed LV lead implant. Using segmentation software, anatomical models of the cardiac chambers, CS, and its branches were overlaid onto the live fluoroscopy using a prototype version of the Philips EP Navigator software to guide lead implantation.

Results: We achieved high‐fidelity segmentations of cardiac chambers, coronary vein anatomy, and accurate registration between the 3D anatomical models and the live fluoroscopy in all 12 patients confirmed by balloon occlusion angiography. The CS was cannulated successfully in every patient and in 11, an LV lead was implanted successfully. (One patient had no acceptable lead values due to extensive myocardial scar.)

Conclusion: Using overlaid 3D segmentations of the CS and cardiac chambers, it is feasible to guide CRT implantation in real time by fusing advanced imaging and fluoroscopy. This enabled successful CRT in a group of patients with previously failed implants. This technology has the potential to facilitate CRT and improve implant success. (PACE 2011; 34:226–234)
Upstream Effect for Atrial Fibrillation: Still a Dilemma?
Authors: CALÒ LEONARDO , MARTINO ANNAMARIA , SCIARRA LUIGI , CICCAGLIONI ANTONIO , DE RUVO ERMENEGILDO , DE LUCA LUCIA , SETTE ANTONELLA , GIUNTA GIUSEPPE , LIOY ERNESTO , FEDELE FRANCESCO
Published: October 2010

Atrial fibrillation is the most common arrhythmia in clinical practice. Ion channel blocking agents are often characterized by limited long‐term efficacy and several side effects. In addition, ablative invasive procedures are neither easily accessible nor always efficacious. The “upstream therapy,” which includes angiotensin‐converting enzyme inhibitors, aldosterone receptor antagonists, statins, glucocorticoids, and ω‐3 poly‐unsaturated fatty acids, targets arrhythmia substrate, influencing atrial structural and electrical remodeling that play an essential role in atrial fibrillation induction and maintenance. The mechanisms involved and the most important clinical evidence regarding the upstream therapy influence on atrial fibrillation are presented in this review. Some open questions are also proposed. (PACE 2011; 111–128)
Long‐Term Outcome of Leads and Patients Following Robotic Epicardial Left Ventricular Lead Placement for Cardiac Resynchronization Therapy
Authors: KAMATH GANESH S. , BALARAM SANDHYA , CHOI ANDREW , KUTEYEVA OLGA , GARIKIPATI NAGA VAMSI , STEINBERG JONATHAN S. , MITTAL SUNEET
Published: October 2010

Introduction: In cardiac resynchronization therapy (CRT), positive clinical response and reverse remodeling have been reported using robotically assisted left ventricular (LV) epicardial lead placement. However, the long‐term performance of epicardial leads and long‐term outcome of patients who undergo CRT via robotic assistance are unknown. In addition, since the LV lead placement is more invasive than a transvenous procedure, it is important to identify patients at higher risk of complications.

Methods: We evaluated 78 consecutive patients (70 ± 11 years, 50 male) who underwent robotic epicardial LV lead placement. The short‐ (<12 months) and long‐term (≥12 months) lead performance was determined through device interrogations. Mortality data were determined by contact with the patient's family and referring physicians and confirmed using the Social Security Death Index.

Results: All patients had successful lead placement and were discharged in stable condition. When compared to the time of implantation, there was a significant increase in pacing threshold (1.0 ± 0.5 vs 2.14 ± 1.2; P < 0.001) and decrease in lead impedance (1010 ± 240 Ω vs 491 ± 209 Ω; P < 0.001) at short‐term follow‐up. The pacing threshold (2.3 ± 1.2 vs 2.14 ± 1.2; P = 0.30) and lead impedance (451 ± 157 Ω vs 491 ± 209 Ω; P = 0.10) remained stable during long‐term follow‐up when compared to short‐term values. At a follow‐up of 44 ± 21 months, there were 20 deaths (26%). These patients were older (77 ± 7 vs 67 ± 11 years; P = 0.001) and had a lower ejection fraction (EF) (13 ± 7% vs 18 ± 9%; P = 0.02) than surviving patients.

Conclusion: Robotically implanted epicardial LV leads for CRT perform well over short‐ and long‐term follow‐up. Older patients with a very low EF are at higher risk of death. The risks and benefits of this procedure should be carefully considered in these patients. (PACE 2011; 34:235–240)
Comparison of the Point‐by‐Point versus Catheter Dragging Technique for Curative Radiofrequency Ablation of Atrial Fibrillation
Authors: YOKOKAWA MIKI , BHANDARI ANIL K. , TADA HIROSHI , SUZUKI ATSUSHI , KAWAMURA MITSUHARU , HO IVAN , CANNOM DAVID S.
Published: October 2010

Background: The relationship between the applied techniques and clinical outcomes after radiofrequency (RF) ablation of atrial fibrillation (AF) remains unclear. We compared the results of ablation by RF delivered via a point‐by‐point versus catheter dragging technique for the treatment of AF.

Methods: This study included 66 patients with drug‐refractory AF who underwent circumferential pulmonary vein (PV) ablation. A point‐by‐point technique was used in 35 (53%) patients (Group I), and catheter dragging technique in the remaining 31 (47%) patients (Group II). If AF persisted or remained inducible after the PV isolation, additional ablation of complex fractionated atrial electrograms and linear ablation were performed.

Results: Significantly, fewer RF applications were delivered in Group II than in Group I. The total RF energy duration delivered was comparable between the two groups (P = 0.55). However, the total energy of RF deliveries was significantly greater in Group II than in Group I (P = 0.02). Despite a longer fluoroscopic exposure time (P = 0.01), the total procedural duration was significantly shorter in Group II than in Group I (P = 0.005). Within 3 months after a single ablation procedure, 24 patients (69%) in Group I versus 13 patients (42%) in Group II had ≥1 recurrence(s) of atrial tachyarrhythmias (P = 0.03). A multivariate analysis showed that a point‐by‐point ablation was the only independent predictor of early atrial tachyarrhythmia recurrences.

Conclusions: The catheter dragging technique for ablation of AF was associated with a lower early recurrence rate of atrial tachyarrhythmias than the point‐by‐point technique. (PACE 2011; 15–22)
Investigating the relationship between hyposalivation and mucosal wetness
Authors: Osailan S , Pramanik R , Shirodaria S , Challacombe SJ , Proctor GB
Published: October 2010

Oral Diseases (2010) 17, 109–114

Background:  Mucosal wetness (MW) reflects the layer of residual saliva that covers the oral mucosal surfaces.

Objectives:  The aim of this study was to determine MW at different oral mucosa sites and to investigate the relationship between MW, unstimulated whole salivary flow rates (UWS) and Clinical Oral Dryness Score (CODS).

Method:  A total of 100 dry mouth patients and 50 healthy subjects participated in the study. MW was sampled with filter paper strips at four sites inside the mouth; anterior hard palate (AHP), buccal mucosa (BUC), anterior tongue (AT), lower lip (LL) and measured with a micro‐moisture meter. Reproducibility was assessed by repeated sampling and diurnal variation was examined.

Results:  Mucosal wetness in healthy subjects differed according to site and means ± SD were; AHP (11 ± 11.7 μm), BUC (32 ± 14.8 μm), AT (65 ± 17.2 μm), and LL (25 ± 13.5 μm). Dry mouth patients with reduced UWS showed increased CODS. MW at all four sites was significantly reduced (P < 0.05) in dry mouth patients compared with the healthy subjects. Reproducibility of MW measurement using the intra‐class correlation coefficient showed agreement at different visits within subject. MW of the AT showed a positive correlation with UWS (P < 0.05).

Conclusion:  Mucosal wetness is a reliable measure of oral dryness and had a positive correlation with UWS.
Lack of modulatory function of coding nucleotide polymorphism S100A2_185G>A in oral squamous cell carcinoma
Authors: Tsai W‐C , Lin Y‐C , Tsai S‐T , Shen W‐H , Chao T‐L , Lee S‐L , Wu L‐W
Published: October 2010

Oral Diseases (2011) 17, 283–290

Objective:  S100A2, a Ca2+ ‐binding protein with two EF‐hands, is a tumor suppressor in oral cancer. Helix III flanking the C‐terminal EF‐hand is implicated to participate in the interaction of S100A2 and its target(s). The aim of this study was to examine if the coding sequence polymorphism S100A2_185G>A, leading to the peptide 62 substitution of asparagine (AAC, A allele) for serine (AGC, G allele) in helix III, had modulation effects on S100A‐mediated tumor suppression.

Subjects and Methods:  We sequenced the coding sequence of S100A2 gene in normal oral keratinocytes (NOKs), dysplastic oral keratinocytes (DOKs), eight oral cancer lines, and 54 pairwise oral cancer specimens. We also compared the in vitro anti‐tumor effect of wildtype (G allele) and variant (A allele) S100A2 expression using cell proliferation, migration, invasion, and colony formation assays.

Results:  With the exception of CAL27 and SCC‐15 cancer lines being heterozygotes of A and G alleles, the remaining oral cells were homozygotic in G alleles. No alterations of anti‐growth, anti‐migration, anti‐invasion, and anti‐colony formation were observed between variant and wildtype cells. Moreover, no minor S100A2_185A allele was detected in 54‐pairwise clinical specimens.

Conclusion:  The coding sequence polymorphism S100A2_185G>A had no regulatory role in S100A2‐mediated tumor suppression in oral cancer.
Shikonin inhibits tumor invasion via down‐regulation of NF‐κB‐mediated MMP‐9 expression in human ACC‐M cells
Authors: Min R , Zun Z , Min Y , Wenhu D , Wenjun Y , Chenping Z
Published: October 2010

Oral Diseases (2011) 17, 362–369

Objective:  The aim of this study was to examine the anti‐invasion effect of Shikonin on human high‐metastatic adenoid cystic carcinoma (ACC‐M) cells and to explain the possible molecular mechanism involved.

Methods:  The ACC‐M cells were treated with Shikonin (0, 2.5, 5, 10 μM) for 24 h. The protein levels and gelatinolytic activities of MMP‐2 and MMP‐9 were analyzed using Western blot and Gelatin zymography test, respectively. Matrigel invasion assays were used to investigate tumor invasive potential and electromobility shift assays were used to determine the activity of NF‐κB.

Results:  The invasiveness of ACC‐M cells was reduced in a dose dependent manner following 24‐h treatment of up to 10 μM of the Shikonin at which concentration no cytotoxicity occurred. The protein levels and gelatinolytic activities of MMP‐9 were significantly suppressed by increasing Shikonin concentrations. The down‐regulation of MMP‐9 appeared to be via the inactivation of NF‐κB as the treatment with Shikonin suppressed the protein level of phosphate‐IkBa, which was accompanied by a decrease in DNA‐binding level of the factor.

Conclusions:  Shikonin inhibits tumor invasion via downregulation of MMP‐9 expression in ACC‐M cells. Pharmacologic inhibition of the NF‐κB‐mediated MMP‐9 expression by Shikonin might be a powerful treatment option for ACC patients in future.
Characterization of aortic aneurysms in cardiovascular disease patients harboring Porphyromonas gingivalis
Authors: Nakano K , Wada K , Nomura R , Nemoto H , Inaba H , Kojima A , Naka S , Hokamura K , Mukai T , Nakajima A , Umemura K , Kamisaki Y , Yoshioka H , Taniguchi K , Amano A , Ooshima T
Published: October 2010

Oral Diseases (2011) 17, 370–378

Objective:  Porphyromonas gingivalis was recently shown to cause intimal hyperplasia in a mouse model by a novel cholesterol‐independent mechanism, suggesting to be a pathogen‐specific feature of cardiovascular diseases. The aim of this study was to characterize the clinical and histopathological features of aortic aneurysms in cardiovascular disease patients harboring oral P. gingivalis.

Subject and methods:  Aortic aneurysm specimens were collected from 76 Japanese patients who underwent surgery, of whom dental plaque specimens were also collected from 31 patients. Bacterial DNA was extracted from each specimen to detect P. gingivalis by polymerase chain reaction. Histopathological analyses of the aortic aneurysm specimens, including immunohistochemical staining for embryonic myosin heavy chain isoform (SMemb) and S100 calcium‐binding protein A9 (S100A9), were also performed.

Results:  The number of aneurysms occurring in the distal aorta was significantly higher in subjects positive for P. gingivalis in dental plaque compared with those who were negative. The expressions of S100A9 and SMemb were also significantly greater in the subjects positive for P. gingivalis in dental plaque. On the other hand, there were no significant differences in adipocellular accumulation between the groups.

Conclusions:  These results suggest that aortic aneurysms in patients harboring oral P. gingivalis have greater expression of S100A9 and proliferative smooth muscle cells, which was different from the present patients without oral P. gingivalis.
Identification of the DSPP mutation in a new kindred and phenotype–genotype correlation
Authors: Lee S‐K , Lee K‐E , Hwang Y‐H , Kida M , Tsutsumi T , Ariga T , Park J‐C , Kim J‐W
Published: October 2010

Oral Diseases (2011) 17, 314–319

Objective:  Hereditary dentin defects can be grouped into three types of dentinogenesis imperfecta (DGI) and two types of dentin dysplasia. Tooth enamel is considered normal in patients with hereditary dentin defects, but is easily worn down and fractured due to DSPP mutation‐induced altered dentin properties. The purposes of this study were to identify genetic cause of a family with type II DGI and enamel defects.

Materials and methods:  We identified a family with type II DGI and a unique form of hypoplastic enamel defect affecting occlusal third of the crown. Family members were recruited for the genetic analysis and DNA was obtained from peripheral whole blood.

Results:  Mutational analysis revealed a T to A transversion in exon 3 of the DSPP (c.53T>A, p.V18D). Haplotype analysis showed that the same mutation arose separately in two different families having DGI with similar enamel defects, indicating that this phenotype is associated with this specific DSPP mutation. Clinical features suggest that enamel formation was affected in the affected individuals during early amelogenesis, in addition to the dentin defect.

Conclusions:  We observed that a DSPP gene mutation not only influences dentinogenesis but also affects early stage amelogenesis.
Determination of Bromine and Iodine Speciation in Drinking Water Using High Performance Liquid Chromatography‐Inductively Coupled Plasma‐Mass Spectrometry
Authors: Liu Wei , Yang Hongxia , Li Bing , Xu Siqi
Published: October 2010

A specific method for the determination of bromine and iodine species in drinking water was developed by using high performance liquid chromatography‐ICP‐MS. An ICS‐A23 ion chromatography column was chosen for the separation of species, with the mobile phase being 0.03 mol l−1 ammonium carbonate at a flow rate of 0.8 ml min−1. The detection limits for BrO3−, Br−, IO3− and I− were 0.032, 0.063, 0.008 and 0.012 μg l−1, respectively. Spectroscopic interferences were only observed in blank samples and mainly resulted from the argon‐potassium polyatomic ion (40Ar39K+). However, this interference was negligible because of the elution and complete separation from that of iodinate under optimised conditions. The method developed was successfully applied to twenty‐two samples of drinking water obtained from a supermarket. Results indicated that 36.4% of the samples had BrO3− concentrations exceeding the Chinese national limit for drinking water of 10 μg l−1.
Simultaneous Determination of Cd, In, Tl and Bi by Isotope Dilution‐Internal Standardisation ICP‐QMS with Corrections Using Externally Measured MoO+/Mo+ Ratios
Authors: Makishima Akio , Kitagawa Hiroshi , Nakamura Eizo
Published: October 2010

A method for the simultaneous determination of Cd with In, Tl and Bi by isotope dilution‐internal standardisation (ID‐IS) ICP‐QMS using the same aliquot for rare earth element and other trace element determinations was developed. Samples mixed with an enriched 149Sm spike were decomposed using a HF‐HClO4 mixture, which was evaporated and then diluted with HNO3. After determination of Sm by ID‐ICP‐QMS and Cd, In, Tl and Bi concentrations were determined using the 149Sm intensity as an internal standard. The interference of MoO+ on Cd+ was corrected using the MoO+/Mo+ ratio separately measured using a Mo standard solution, and the validity of the externally determined oxide‐forming ratio correction was evaluated. The MoO+/Mo+ ratios measured using the standard solution and samples were ∼ 0.0002 and < 0.002, respectively. Detection limits for Cd, In, Tl and Bi in silicate samples were at levels of < 1 ng g−1 with a total uncertainty of < 7%. Cadmium in the carbonaceous chondrites, Orgueil (CI1), Murchison (CM2) and Allende (CV3) as well as Cd, In, Tl and Bi in the reference materials, JB‐2, JB‐3, JA‐1, JA‐2, JA‐3, JP‐1 (GSJ), BHVO‐1, AGV‐1, PCC‐1 and DTS‐1 (USGS) and NIST SRM 610, 612, 614 and 616 were determined to show the applicability of this method.
Centaurea nerimaniae sp. nov. (Asteraceae) from south Anatolia, Turkey
Authors: Kültür Şükran
Published: October 2010

Centaurea nerimaniaeŞ. Kültür sp. nov. (Asteraceae) is described and illustrated from south Anatolia, Turkey. It is morphologically similar to C. antiochia Boiss. var. praealta (Boiss. & Bal.) Wagenitz. The geographical distribution of the new species and related species is mapped. The chromosome number of C. nerimaniae (counted in root tips) is 2n=20.
High Rotation Number Effects on Heat Transfer in a Rectangular (AR=2:1) Two-Pass Channel
Authors: Huh Michael , Lei Jiang , Liu Yao-Hsien , Han Je-Chin
Published: October 2010

This paper experimentally investigated the rotational effects on heat transfer in a smooth two-pass rectangular channel (AR=2:1), which is applicable to the cooling passages in the midportion of the gas turbine blade. The test channel has radially outward flow in the first passage and radially inward flow in the second passage after a 180 deg sharp turn. In the first passage, the flow is developing and heat transfer is increased compared with the fully developed case. Rotation slightly reduces the heat transfer on the leading surface and increases heat transfer on the trailing surface in the first pass. Heat transfer is highly increased by rotation in the turn portion of the first pass on both leading and trailing surfaces. Rotation increased heat transfer enhancement in the tip region up to a maximum Nu ratio (Nu/Nus) of 1.83. In the second passage, under rotating conditions, the leading surface experienced heat transfer enhancements above the stationary case while the trailing surface decreased. The current study has more than four times the range of the rotation number previously achieved for the 2:1 aspect ratio channel. The increased range of the rotation number and buoyancy parameter reached in this study are 0–0.45 and 0–0.8, respectively. The higher rotation number and buoyancy parameter have been correlated very well to predict the rotational heat transfer in the two-pass, 2:1 aspect ratio flow channel.
The Effect of Turning Vanes on Pressure Loss and Heat Transfer of a Ribbed Rectangular Two-Pass Internal Cooling Channel
Authors: Schüler Marco , Zehnder Frank , Weigand Bernhard , von Wolfersdorf Jens , Neumann Sven Olaf
Published: October 2010

Gas turbine blades are usually cooled by using ribbed serpentine internal cooling passages, which are fed by extracted compressor air. The individual straight ducts are connected by sharp 180 deg bends. The integration of turning vanes in the bend region lets one expect a significant reduction in pressure loss while keeping the heat transfer levels high. Therefore, the objective of the present study was to investigate the influence of different turning vane configurations on pressure loss and local heat transfer distribution. The investigations were conducted in a rectangular two-pass channel connected by a 180 deg sharp turn with a channel height-to-width ratio of H/W=2. The channel was equipped with 45 deg skewed ribs in a parallel arrangement with e/dh=0.1 and P/e=10. The tip-to-web distance was kept constant at Wel/W=1. Spatially resolved heat transfer distributions were obtained using the transient thermochromic liquid crystal technique. Furthermore static pressure measurements were conducted in order to determine the influence of turning vane configurations on pressure loss. Additionally, the configurations were investigated numerically by solving the Reynolds-averaged Navier–Stokes equations using the finite-volume solver FLUENT. The numerical grids were generated by the hybrid grid generator CENTAUR. Three different turbulence models were considered: the realizable k-ε model with two-layer wall treatment, the k-ω-SST model, and the v2-f turbulence model. The results showed a significant influence of the turning vane configuration on pressure loss and heat transfer in the bend region and the outlet pass. While using an appropriate turning vane configuration, pressure loss was reduced by about 25%, keeping the heat transfer at nearly the same level in the bend region. An inappropriate configuration led to an increase in pressure loss while the heat transfer was reduced in the bend region and outlet pass.
The Effect of Side Wall Mass Extraction on Pressure Loss and Heat Transfer of a Ribbed Rectangular Two-Pass Internal Cooling Channel
Authors: Schüler Marco , Zehnder Frank , Weigand Bernhard , von Wolfersdorf Jens , Neumann Sven Olaf
Published: October 2010

Gas turbine blades are often cooled by using combined internal and external cooling methods where for internal cooling purposes, usually, serpentine passages are applied. In order to optimize the design of these serpentine passages it is inevitable to know the influence of mass extraction due to film cooling holes, dust holes, or due to side walls for feeding successive cooling channels as for the trailing edge on the internal cooling performance. Therefore, the objective of the present study was to analyze the influence of side wall mass extraction on pressure loss and heat transfer distribution in a two-pass internal cooling channel representing a cooling scheme with flow towards the trailing edge. The investigated rectangular two-pass channel consisted of an inlet and outlet duct with a height-to-width ratio of H/W=2 connected by a 180 deg sharp bend. The tip-to-web distance was kept constant at Wel/W=1. The mass extraction was realized using several circular holes in the outlet pass side wall. Two geometric configurations were investigated: A configuration with mass extraction solely in the outlet pass and a configuration with mass extraction in the bend region and outlet pass. The extracted mass flow rate was 0%, 10%, and 20% of the inlet channel mass flow. Spatially resolved heat transfer distributions were obtained using the transient thermochromic liquid crystal technique. Pressure losses were determined in separate experiments by local static pressure measurements. Furthermore, a computational study was performed solving the Reynolds-averaged Navier–Stokes equations using the commercial finite-volume solver FLUENT. The numerical grids were generated using the hybrid grid generator CENTAUR. Three different turbulence models were considered: the realizable k-ε model with two-layer wall treatment, the k-ω-SST model, and the v2-f model. The experimental data of the investigation of side wall ejection showed that the heat transfer in the bend region slightly increased when the ejection were in operation, while the heat transfer in the section of the outlet channel with side wall ejection was nearly not affected. After this section, a decrease in heat transfer was observed, which can be attributed to the decreased mainstream mass flow rate.
Compressor Leading Edge Spikes: A New Performance Criterion
Authors: Goodhand Martin N. , Miller Robert J.
Published: October 2010

Compressor blades often have a small “spike” in the surface pressure distribution at the leading edge. This may result from blade erosion, manufacture defects, or compromises made in the original design process. This paper investigates the effect of these spikes on profile loss, and presents a criterion to ensure they are not detrimental to compressor performance. In the first part of the paper, two geometries of leading edge are tested. One has a small spike, typical of those found on modern compressors; the other has no spike, characteristic of an idealized leading edge. Testing was undertaken on the stator of a single-stage low speed compressor. The time resolved boundary layer was measured using a hot-wire microtraversing system. It is shown that the presence of the small spike changes the time resolved transition process on the suction surface, but that this results in no net increase in loss. In the second part of the paper, spike height is systematically changed using a range of leading edge geometries. It is shown that below a critical spike height, the profile loss is constant. If the critical spike height is exceeded, the leading edge separates and profile loss rises by 30%. Finally, a criterion is developed, based on the total diffusion across the spike. Three different leading edge design philosophies are investigated. It is shown that if the spike diffusion factor is kept below 0.1 over the blade’s incidence range, performance is unaffected by leading edge geometry.
Enhancing the Stability of Subsonic Compressors Using Casing Grooves
Authors: Houghton Tim , Day Ivor
Published: October 2010

Casing grooves are known to increase the stable operating range of axial compressors. The mechanism by which this stability enhancement occurs is poorly understood. This paper develops a better understanding of the behavior of casing grooves through analysis of new data. An experimental parametric study is used to demonstrate the effect of varying the axial location of a single casing groove on the stability and efficiency of the compressor. The effect that the groove has on rotor outflow blockage, blade loading, and the near-casing flow field is then investigated using both experimental and computational methods. It is found that the interaction of the groove with the flow field is different when the groove is positioned forward or aft relative to the blade. The interaction of the groove with the flow in the tip region in both of these positions is presented in detail. Finally, the implications of these findings for the design of casing grooves of different depths are discussed.