bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Purchasing Framework for B2B Pricing Decisions and Risk‐sharing in Supply Chains*
Authors: Arcelus F. J. , Pakkala T. P. M. , Srinivasan G. 
Published: June 2007

ABSTRACTThis paper presents a common modelling structure for (i) the implementation of operational policies by individual purchasing managers of risk‐sharing agreements among supply‐chain partners, and (ii) the integration of brick and click purchasing policies in a B2B. The problem of price uncertainty created within these two environments is modelled as a stochastic repetitive‐sales problem, applicable to any probability distribution. The model identifies sufficient conditions for regenerative ordering cycles, which allows for the use of the renewal reward theorem. The end result is a two‐price purchasing policy, which may substantially ease implementation problems across a global corporation's purchasing managers world‐wide and across B2B markets.
Heterogeneity of Ventricular Fibrillation Dominant Frequency During Global Ischemia in Isolated Rabbit Hearts
Authors: CALDWELL JANE , BURTON FRANCIS L. , SMITH GODFREY L. , COBBE STUART M. 
Published: June 2007

Introduction
: Ventricular fibrillation (VF) studies show that ECG‐dominant frequency (DF) decreases as ischemia develops. This study investigates the contribution of the principle ischemic metabolic components to this decline. Methods and Results: Rabbit hearts were Langendorff‐perfused at 40 mL/min with Tyrode's solution and loaded with RH237. Epicardial optical action potentials were recorded with a photodiode array (256 sites, 15 × 15 mm). After 60 seconds of VF (induced by burst pacing), global ischemia was produced by low flow (6 mL/min), or the solution changed to impose hypoxia (95% N2/5% CO2), low pHo (6.7, 80% O2/20% CO2), or raised [K+]o (8 mM). DF of the optical signals was determined at each site. Conduction velocity (CV), action potential duration (APD90), effective refractory period (ERP), activation threshold, dV/dtmax, and membrane potential were measured in separate experiments during ventricular pacing. During VF, ischemia decreased DF in the left ventricle (LV) (to [58 ± 6]%, P < 0.001), but not the right (RV) ([93 ± 5]%). Raised [K+]o reproduced this DF pattern (LV: [67 ± 12]%, P < 0.001; RV: [95 ± 9]%). LV DF remained elevated in hypoxia or low pHo. During ventricular pacing, ischemia decreased CV in LV but not RV. Raised [K+]o did not change CV in either ventricle. Ischemia and raised [K+]o shortened APD90 without altering ERP. LV activation threshold increased in both ischemia and raised [K+]o and was associated with diastolic depolarization and decreased dV/dtmax. Conclusions: These results suggest that during VF, decreased ECG DF in global ischemia is largely due to elevated [K+]o affecting the activation thresholds in the LV rather than RV.
Performance of Phonoelectrocardiographic Left Ventricular Systolic Time Intervals and B‐Type Natriuretic Peptide Levels in the Diagnosis of Left Ventricular Dysfunction
Authors: Moyers Brian , Shapiro Mia , Marcus Gregory M. , Gerber Ivor L. , McKeown Barry H. , Vessey Joshua C. , Jordan Mark V. , Huddleston Michele , Foster Elyse , Chatterjee Kanu , Michaels Andrew D. 
Published: June 2007

Background: Systolic time intervals measured by echocardiography and carotid artery tracings are validated methods of assessing left ventricular function. However, the clinical utility of phonoelectrocardiographic systolic time intervals for predicting heart failure using newer technology has not been evaluated. Methods: We enrolled 100 adult patients undergoing left heart catheterization. Participants underwent computerized phonoelectrocardiographic analysis, left ventricular end‐diastolic pressure (LVEDP) measurement, transthoracic echocardiographic measurement of left ventricular ejection fraction (LVEF), and B‐type natriuretic peptide (BNP) testing. The heart rate‐adjusted systolic time intervals included the time from the Q wave onset to peak S1 (electromechanical activation time, EMAT), Q wave onset to peak S2 (electromechanical systole, Q‐S2), and peak S1 to peak S2 (left ventricular systolic time, LVST). Left ventricular dysfunction was defined as the presence of both LVEDP >15 mmHg and LVEF <50%. Results: EMAT (r =−0.51; P < 0.0001), EMAT/LVST (r =−0.41; P = 0.0001), and Q‐S2 (r =−0.39; P = 0.0003) correlated with LVEF, but not with LVEDP. An abnormal EMAT ≥15 (odds ratio 1.38, P < 0.0001) and EMAT/LVST ≥0.40 (OR 1.13, P = 0.002) were associated with left ventricular dysfunction. EMAT ≥15 had 44% sensitivity, 94% specificity, and a 7.0 likelihood ratio for left ventricular dysfunction, while EMAT/LVST ≥0.40 had 55% sensitivity, 95% specificity, and a 11.7 likelihood ratio. In patients with an intermediate BNP (100–500 pg/mL), the likelihood ratio increased from 1.1 using the BNP result alone to 11.0 when adding a positive EMAT test for predicting left ventricular dysfunction. Conclusions: Phonoelectrocardiographic measures of systolic time intervals are insensitive but highly specific tests for detecting abnormalities in objective markers of left ventricular function. EMAT and EMAT/LVST provide diagnostic information independent of BNP for detecting patients with left ventricular dysfunction.
Temporal Variations in Microvolt T‐Wave Alternans Testing after Acute Myocardial Infarction
Authors: Oliveira Mário Martins , Fiarresga António , Pelicano Nuno , Da Silva Nogueira , Timóteo Ana Teresa , Carlos Isabel , Silva Sofia , Quininha Jorge 
Published: June 2007

Background: Microvolt T‐wave alternans (TWA) have been accepted as a tool for assessing vulnerability to ventricular tachyarrhythmias. There is lack of data concerning prospective temporal variations in TWA measurements after acute myocardial infarction (AMI). We analysed the temporal patterns of TWA in post‐AMI patients. Methods and Results: TWA tests were performed <1 month (TWA_early) and 6 months (TWA_late) after AMI in 51 consecutive patients treated with successful percutaneous coronary intervention (PCI). Twenty seven patients (53%) had anterior wall infarctions and 24 (47%) had inferior/lateral wall infarctions. TWA was measured during a treadmill manual exercise protocol and defined as positive, negative and indeterminate. Group A included patients with TWA negative in both tests and Group B included those with TWA abnormal (positive or indeterminate) at first or second determinations. TWA_early was negative, positive and indeterminate in 38 (74.6%), 8 (15.6%) and 5 (9.8%) patients, respectively, whereas TWA_late was negative, positive and indeterminate in 30 (58.9%), 14 (27.4%) and 7 (13.7%) patients, respectively. TWA_early was classified as normal in 74.6% and abnormal in 25.4% of the cases, and TWA_late was normal in 58.9% and abnormal in 41.1%. TWA tests were concordant in 36 patients (70.6%) and discordant 15 patients (29.4%). At TWA_late, 10 patients (19.6%) changed from TWA negative to TWA abnormal and 4 patients (7.8%) from TWA abnormal to TWA negative. After TWA_early+TWA_late, 45% of the patients had 1 test classified as abnormal. Left ventricular ejection fraction was <50% in 22% of Group A and 52% of Group B (P = 0.037). Conclusions: In the era of primary PCI, temporal changes in TWA measurements may occur frequently during the first 6 months post‐AMI. These findings should be considered in risk stratification strategies following AMI.
The 〈〈Chaos Theory〉〉 and Nonlinear Dynamics in Heart Rate Variability Analysis: Does it Work in Short‐Time Series in Patients with Coronary Heart Disease?
Authors: Krstacic Goran , Krstacic Antonija , Smalcelj Anton , Milicic Davor , Jembrek‐Gostovic Mirjana 
Published: June 2007

Background: Dynamic analysis techniques may quantify abnormalities in heart rate variability (HRV) based on nonlinear and fractal analysis (〈〈chaos theory〉〉). The article emphasizes clinical and prognostic significance of dynamic changes in short‐time series applied on patients with coronary heart disease (CHD) during the exercise electrocardiograph (ECG) test. Methods: The subjects were included in the series after complete cardiovascular diagnostic data. Series of R‐R and ST‐T intervals were obtained from exercise ECG data after sampling digitally. The 〈〈range rescaled analysis〉〉 method determined the fractal dimension of the intervals. To quantify fractal long‐range correlation's properties of heart rate variability, the detrended fluctuation analysis technique was used. Approximate entropy (ApEn) was applied to quantify the regularity and complexity of time series, as well as unpredictability of fluctuations in time series. Results: It was found that the short‐term fractal scaling exponent (α1) is significantly lower in patients with CHD (0.93 ± 0.07 vs 1.09 ± 0.04; P < 0.001). The patients with CHD had higher fractal dimension in each exercise test program separately, as well as in exercise program at all. ApEn was significant lower in CHD group in both RR and ST‐T ECG intervals (P < 0.001). Conclusions: The nonlinear dynamic methods could have clinical and prognostic applicability also in short‐time ECG series. Dynamic analysis based on 〈〈chaos theory〉〉 during the exercise ECG test point out the multifractal time series in CHD patients who loss normal fractal characteristics and regularity in HRV. Nonlinear analysis technique may complement traditional ECG analysis.
Magnitude, Mechanism, and Reproducibility of QT Interval Differences Between Superimposed Global and Individual Lead ECG Complexes
Authors: Kligfield Paul , Tyl Benoit , Maarek Martine , Maison‐Blanche Pierre 
Published: June 2007

Background: The global QT interval, emerging as a standard measurement provided by digital electrocardiographs, is defined by the earliest QRS onset and latest T‐wave offset that occur in any of the standard leads. Differences between global ECG measurements and those from individual ECG leads have implications for the redefinition of normal values, for recognition of disease, and for drug safety. This study sought to quantify the differences between global QT intervals measured from 12 superimposed ECG leads with QT intervals and from single lead complexes, to examine the separate effects of QRS onset and T‐wave offset on these differences, and to examine the reproducibility of these measurements. Methods: QTo intervals (Q onset to T offset) from 50 digitized ECGs sampled at 500 Hz were examined by computer assisted derivation of representative complexes from standard leads II, V2, and V3, by both baseline and tangent methods. Global QTo intervals were measured from superimposition of the representative complexes of all 12 leads. A time‐coherent matrix of waveform onset and offset points allowed direct comparison of the components of the differences. Results: Global QTo and Bazett‐adjusted global QTc were greater than each of the baseline and tangent measurements in representative leads II, V2, and V3, with mean differences ranging from 8 to 18 ms. QRS onset was earlier in the global complex than in each of the representative leads, with mean differences of 3–5 ms, whereas T‐wave offset was significantly later in the global complex than in each of the representative leads, with mean differences of 5–11 ms. Remeasurement of all ECGs after an interval of 6 months confirmed the relative magnitudes of the global and individual lead QTo durations and small mean differences between pairs (−0.9 to 2.7 ms). Although global QTo had the largest mean difference (only 2.7 ms), it had the smallest standard deviation of the mean difference and lowest coefficient of variability (1.58%) of all measurements. Conclusion: Global QT measurements are systematically larger than measurements from representative complexes of individual leads. These differences result from the combined effects of earlier QRS onset and later T‐wave offset in the global complex, with T‐wave offset the more dominant component of the difference.
Web‐Based Virtual Cardiac Symposia: A New Approach for Worldwide Professional Medical Education
Authors: Dubner Sergio J. , Moss Arthur J. , Schapachnik Edgardo S. , Levine Paul A. , Perez Riera Andres R. , Camm John , Zareba Wojciech ,   in behalf of the Educational Committee of the International Society for Holter and Noninvasive Electrocardiology
Published: June 2007

Aim: The Internet is an extremely powerful tool for the transmission of data and knowledge, and the question is whether this technology can be used effectively in continuing medical education. We present our experience with worldwide, web‐based virtual symposia for practicing physicians. Methods: The International Society for Holter and Noninvasive Electrocardiography (ISHNE) decided four years ago to conduct a series of cardiology‐related educational activities for physicians utilizing a web‐based approach. Six educational events under the format of virtual symposia were held on the Internet during the years 2002 to 2006. These Internet events included symposia on Brugada syndrome (2002), the long QT syndrome (2004), arrhythmogenic right ventricular dysplasia (2005), atrial fibrillation (2005), heart failure (2006), and sudden cardiac death (2006). Results: During the past four years, there has been a dramatic and progressive increase in the number of physician registrants, the number of countries represented, and the number of lectures downloaded with each subsequent virtual symposium. For example, during the month of October 2006, the Internet‐based sudden cardiac death symposium involved 14,087 physician registrants from 120 countries with 64,939 lectures downloaded. The top lecture was downloaded 11,251 times, and over 200 e‐mail questions and replies were exchanged. The average time per visit to the web site was 12.5 minutes. Conclusion: The progressively increasing numbers of physician registrants from around the world who participated in these web‐based, virtual symposia suggest that this approach is answering an unmet professional educational need. This Internet approach adds an important, new, low‐cost dimension to continuing medical education.
The barrier component and the driving force component of transepidermal water loss and their application to skin irritant tests
Authors: Endo Koji , Suzuki Noboru , Yoshida Osamu , Sato Hirayuki , Fujikura Yoshiaki 
Published: June 2007

Background/aim: According to Fick's law of diffusion, the rate of transepidermal water loss (TEWL) is determined by a barrier component and a driving force component. The objective of this study is to propose novel indicators for the assessment of skin irritation potential from chemicals using these components.Methods: Before and after acetone/ether (AE), sodium lauryl sulfate (SLS) and nicotinic acid methyl ester (NME) treatments, the apparent mass transfer coefficient of water, K, of the stratum corneum (SC) and the apparent water vapor pressure, Pd, at the interface between SC and epidermis were estimated as measures of the SC barrier and the driving force, respectively.Results: After AE treatment, K showed marked increase and Pd remained approximately constant. All participants reacted to NME with erythema and the laser‐Doppler flowmetry (LDF) value peaked at around 30 min. While there was a change in Pd, which parallels with LDF changes, K showed little variation. Repeated SLS treatment induced a slight increase in Pd besides an increase in K. In the meantime, all participants reacted with subtle erythema.Conclusions: Our results suggest that not only the SC barrier but also the driving force determines variations in the TEWL rates during skin irritant tests. Together, K and Pd will provide us with invaluable information about skin condition.
Stimulatory response of neutrophils from periodontitis patients with periodontal pathogens
Authors: Restaíno CG , Chaparro A , Valenzuela MA , Kettlun AM , Vernal R , Silva A , Puente J , Jaque MP , León R , Gamonal J 
Published: June 2007

Objective:  Neutrophils play a crucial role in the defense of invading bacteria by releasing biologically active molecules. The response of peripheral blood neutrophils was studied in periodontitis‐affected patients and in healthy controls towards stimulation to Porphyromonas gingivalis (Pg) and Actinobacillus actinomycetemcomitans (Aa) extracts.Materials and methods:  Peripheral venous blood was drawn from 23 adult patients with moderate to advanced chronic periodontitis (probing depth ≥5 mm, attachment loss ≥3 mm), and 30 healthy volunteers. Neutrophil response followed by metalloproteinase‐9 (MMP‐9) and interleukin‐8 (IL‐8) secretion was assayed by zymography and enzyme‐linked immunosorbent assay, respectively, on both whole blood and purified neutrophils. In addition to periodontal pathogen extracts, known stimulating agents were tested, such as Escherichia coli‐lipopolysaccharide (LPS), phytohemagglutinin, and zymosan A.Results:  Neutrophil response, expressed as a secretion ratio under stimulated and non‐stimulated conditions, measured in whole blood, showed no differences between periodontitis and healthy controls. Instead, in purified neutrophils from patients, MMP‐9 exhibited a significantly higher secretion ratio with LPS and Pg (1.5‐ to 2‐fold), whereas IL‐8 showed a larger increase in secretion ratio (3‐ to 7‐fold) in the presence of Pg, Aa, LPS, and zymosan A.Conclusion:  Peripheral neutrophils of periodontitis‐affected patients are more reactive as suggested by their significantly higher response toward periodontal pathogen extracts and other stimulating agents.
Low‐energy laser therapy for prevention of oral mucositis in hematopoietic stem cell transplantation
Authors: Jaguar GC , Prado JD , Nishimoto IN , Pinheiro MC , De Castro DO , Da Cruz Perez DE , Alves FA 
Published: June 2007

Aim:  To evaluate the clinical effects of laser therapy on the prevention and reduction of oral mucositis in patients who underwent hematopoietic stem cell transplantation (HSCT).Patients and methods:  From January 2003 to September 2004, 24 patients received prophylactic laser therapy (L+ group). The applications started from the beginning of the conditioning regimen up to day +2. The oral assessment was performed daily until day +30. This group was compared with historical controls, namely 25 patients, who did not receive laser therapy (L− group).Results:  All patients developed some grade of mucositis. However, the L− group presented initial mucositis by 4.36 days, whereas the L+ group presented it in 6.12 days (P = 0.01). The maximum mucositis occurred between day +2 and day +6 with healing by day +25 in the L− group and between day +2 and day +7 with healing by day +14 for the L+ group (P = 0.84). Laser therapy also reduced the time of oral pain from 5.64 to 2.45 days (P = 0.04), and decreased the consumption of morphine (P = 0.07).Conclusion:  This study suggests that laser therapy can be useful in oral mucositis to HSCT patients and improve the patient's quality of life. However, controlled randomized trials should be performed to confirm the real efficacy of laser therapy.
Sjögren's syndrome sufferers have increased oral yeast levels despite regular dental care
Authors: Leung KCM , McMillan AS , Cheung BPK , Leung WK 
Published: June 2007

Aim:  To investigate the prevalence and quantity of oral yeasts and their association with oral candidiasis in Sjögren's syndrome (SS) patients receiving regular dental care.Materials and methods:  Yeasts in oral rinse and full‐mouth supra‐gingival plaque samples from 25 primary SS, 27 secondary SS and 29 control subjects were selectively cultured. All yeasts except single‐species isolates were genotyped using pulsed field gel electrophoresis (PFGE).Results:  Ten (19%) SS sufferers had symptomless candidiasis. SS subjects had a higher prevalence (73%vs 7%) and quantity of yeasts than controls in both oral rinse and plaque samples (P < 0.05). The prevalence of yeasts in plaque was associated with candidiasis regardless of denture wearing (P ≤ 0.04). Candida albicans was the predominant yeast isolated. PFGE showed 20 (66% of total) C. albicans isolate pairs, i.e. C. albicans species isolated from plaque and oral rinse samples of the same individual, were of closely related genetic clonal types (P < 0.01).Conclusions:  Despite effective oral hygiene, more SS subjects than controls had detectable levels of oral yeasts and their presence in supra‐gingival plaque was associated with candidiasis. Candida albicans colonized supra‐gingival biofilm even in well‐maintained SS individuals, posing a challenge to the control of oral candidiasis.
A Computer‐Controlled Anesthetic Delivery System in a Periodontal Practice: Patient Satisfaction and Acceptance
Authors: ROSENBERG EDWIN S. 
Published: June 2007

ABSTRACT Background: Many dental patients are fearful about receiving intraoral injections of local anesthetic. In fact, many patients cite injections as their primary reason for avoiding dental treatment. In late 1997, however, a computerized local anesthetic delivery system was introduced to address the problems of pain and anxiety associated with these injections. The author initiated a yearlong assessment study in which patients evaluated and rated injections administered with the computerized device as compared with previously administered standard injections. Methods: One hundred and fifty randomly selected patients received local anesthesia delivered via the computer‐controlled anesthetic delivery system. All patients had at some time received standard injections during treatment at the practice. Different types of injections were administered to all quadrants, enabling the researcher to qualify results according to injection type and location. Patient responses were recorded and evaluated to assess the levels of anxiety and pain associated with the computer‐driven system. Results: Overall, 71.4% of patients reported the experience to be superlative, positive, or somewhat positive. Results indicated that the system was highly preferred to traditional injection techniques, regardless of the arch and quadrant receiving the injection. Several factors may have contributed to this preference, including increased patient comfort, the nonthreatening appearance of the instrument, and the lack of residual facial numbness commonly associated with oral anesthetic injections.
Sensitivity and Tooth Whitening Agents
Authors: POHJOLA RANDALL M. , BROWNING WILLIAM D. , HACKMAN STEVEN T. , MYERS MICHAEL L. , DOWNEY MARY C. 
Published: June 2007

ABSTRACT Purpose: Three commercially available dentist‐prescribed home‐applied bleaching systems were evaluated to identify the incidence of sensitivity and to compare the efficacy of whitening the maxillary anterior teeth of 18 patients. Methods: Nite White Excel 2Z (Discus Dental), fx (Challenge Products), and Rembrandt Xtra‐Comfort (DenMat Corp.) were randomly assigned to six patients each. The fx product was used as a control since it was not advertised as a zero sensitivity product. The manufacturers' instructions for tray fabrication and use were followed while the patients bleached for 2 weeks. The patients kept a diary and were recalled at 1 week, 2 weeks, and 4 weeks. The shade change and the presence or absence of any sensitivity were evaluated at each recall. Results: Nite White Excel 2Z was used for 83 days of treatment with the following percentage of positive sensitivity reported: 0% hot and cold, 2.4% throat sensitivity, 2.4% tongue sensitivity, and 25.3% gingival sensitivity. Rembrandt Xtra‐Comfort was used for 84 days with 0% hot and cold, 0% throat, 11.9% tongue, and 27.4% gingival sensitivity reported. The fx product was used for 83 days and resulted in 14.5% hot and cold, 3.6% throat, 1.2% tongue, and 16.9% gingival sensitivity. All products lightened the teeth an average of eight shade tabs on the Vita guide. There was a statistically significant difference between the groups when comparing the presence of sensitivity (chi‐squared test, p < .001) but not when comparing the shade tab change.