bluuebunny/crossref_metadata_2025 huggingface dataset:
Drinking Alcohol before Age 13 and Negative Outcomes in Late Adolescence
Authors: Peleg‐Oren Neta , Saint‐Jean Gilbert , Cardenas Gabriel A. , Tammara Hayley , Pierre Colbert
Published: August 2009

Background:  Research has shown that adolescents who begin drinking at an early stage in life are at greater risk of developing alcohol dependency, as well as a variety of negative outcomes, for instance, delinquent behavior. Most of these studies have focused on those who begin drinking in middle adolescence, but little attention has been paid to youth who initiate drinking under the age of 13. Twenty percent of adolescents have begun using alcohol by the age of 13. The purpose of the study is to examine whether initiating alcohol use before the age of 13 exacerbates negative outcomes in late adolescence.

Methods:  Data for the study were derived from 2 school‐based statewide surveys conducted in Florida: the 2005 YRBS and the 2006 FYSAS. The sample included 12,352 11th and 12th grade students divided into 3 groups: students who initiated alcohol use under the age of 13, students who initiated alcohol use at age 13 or later, and students who never used alcohol.

Results:  Results showed that after adjusting for gender, ethnicity/race, and grade, adolescents who initiated alcohol use before age 13 were more likely to report problems with school performance and display delinquent behaviors (carrying a gun, carrying a weapon to school, and recent marijuana use).

Conclusion:  Although no temporal relationships can be determined between drinking alcohol before age 13 and delinquent behavior outcomes, the results suggested that adolescents under the age of 13 need to be included in national epidemiological surveys on alcohol use and more efforts need to be directed toward the implementation of prevention programs early in elementary and middle schools.
Alcohol Price and Intoxication in College Bars
Authors: O’Mara Ryan J. , Thombs Dennis L. , Wagenaar Alexander C. , Rossheim Matthew E. , Merves Michele L. , Hou Wei , Dodd Virginia J. , Pokorny Steven B. , Weiler Robert M. , Goldberger Bruce A.
Published: August 2009

Background:  Many population studies find that alcohol prices are inversely related to alcohol consumption and alcohol‐related problems, including among college students and young adults. Yet, little is known about the “micro‐level” effects of alcohol price on the behavior of individual consumers in natural drinking settings such as college bars. Therefore, we assessed patron’s cost per gram of ethanol consumed at on‐premise drinking establishments and its association with intoxication upon leaving an establishment.

Methods:  On 4 consecutive nights during April 2008, data were collected from 804 patrons exiting 7 on‐premise establishments in a bar district located adjacent to a large university campus in the southeastern United States. Anonymous interview and survey data were collected as well as breath alcohol concentration (BrAC) readings. We calculated each patron’s expenditures per unit of ethanol consumed based on self‐reported information regarding the type, size, number, and cost of consumed drinks.

Results:  A multivariable model revealed that a 10‐cent increase in cost per gram of ethanol at on‐premise establishments was associated with a 30% reduction in the risk of exiting an establishment intoxicated (i.e., BrAC ≥ 0.08 g/210 l).

Conclusions:  The results are consistent with economic theory and population‐level research regarding the price elasticity of alcoholic beverages, which show that increases in alcohol prices are accompanied by less alcohol consumption. These findings suggest that stricter regulation of the drink discounting practices of on‐premise drinking establishments would be an effective strategy for reducing the intoxication levels of exiting patrons.
Fetal Exposure to Moderate Ethanol Doses: Heightened Operant Responsiveness Elicited by Ethanol‐Related Reinforcers
Authors: March Samanta M. , Abate Paula , Spear Norman E. , Molina Juan Carlos
Published: August 2009

Background:  Prenatal exposure to moderate ethanol doses during late gestation modifies postnatal ethanol palatability and ingestion. The use of Pavlovian associative procedures has indicated that these prenatal experiences broaden the range of ethanol doses capable of supporting appetitive conditioning. Recently, a novel operant technique aimed at analyzing neonatal predisposition to gain access to ethanol has been developed. Experiment 1 tested the operant conditioning technique for developing rats described by Arias and colleagues (2007) and Bordner and colleagues (2008). In Experiment 2, we analyzed changes in the disposition to gain access to ethanol as a result of moderate prenatal exposure to the drug.

Methods:  In Experiment 1, newborn pups were intraorally cannulated and placed in a supine position that allowed access to a touch‐sensitive sensor. Paired pups received an intraoral administration of a given reinforcer (milk or quinine) contingent upon physical contact with the sensor. Yoked controls received similar reinforcers only when Paired pups activated the circuit. In Experiment 2, natural reinforcers (water or milk) as well as ethanol (3% or 6% v/v) or an ethanol‐related reinforcer (sucrose compounded with quinine) were tested. In this experiment, pups had been exposed to water or ethanol (1 or 2 g/kg) during gestational days 17 to 20.

Results:  Experiment 1 confirmed previous results showing that 1‐day‐old pups rapidly learn an operant task to gain access to milk, but not to gain access to a bitter tastant. Experiment 2 showed that water and milk were highly reinforcing across prenatal treatments. Furthermore, general activity during training was not affected by prenatal exposure to ethanol. Most importantly, prenatal ethanol exposure facilitated conditioning when the reinforcer was 3% v/v ethanol or a psychophysical equivalent of ethanol’s gustatory properties (sucrose–quinine).

Conclusions:  The present results suggest that late prenatal experience with ethanol changes the predisposition of the newborn to gain access to ethanol‐related stimuli. In conjunction with prior literature, this study emphasizes the fact that intrauterine experience with ethanol not only augments ethanol’s palatability and ingestion, but also facilitates the acquisition of response–stimulus associations where the drug acts as an intraoral reinforcer.
The Effects of Fetal Alcohol Syndrome on Response Execution and Inhibition: An Event‐Related Potential Study
Authors: Burden Matthew J. , Andrew Colin , Saint‐Amour Dave , Meintjes Ernesta M. , Molteno Christopher D. , Hoyme H. Eugene , Robinson Luther K. , Khaole Nathaniel , Nelson Charles A. , Jacobson Joseph L. , Jacobson Sandra W.
Published: August 2009

Background:  Both executive function deficits and slower processing speed are characteristic of children with fetal alcohol exposure, but the temporal dynamics of neural activity underlying cognitive processing deficits in fetal alcohol spectrum disorder have rarely been studied. To this end, event‐related potentials (ERPs) were used to examine the nature of alcohol‐related effects on response inhibition by identifying differences in neural activation during task performance.

Methods:  We recorded ERPs during a Go/No‐go response inhibition task in 2 groups of children in Cape Town, South Africa (M age = 11.7 years; range = 10 to 13)—one diagnosed with fetal alcohol syndrome (FAS) or partial FAS (FAS/PFAS; n = 7); the other, a control group whose mothers abstained or drank only minimally during pregnancy (n = 6). Children were instructed to press a “Go” response button to all letter stimuli presented except for the letter “X,” the “No‐go” stimulus, which occurred relatively infrequently.

Results:  Task performance accuracy and reaction time did not differ between groups, but differences emerged for 3 ERP components—P2, N2, and P3. The FAS/PFAS group showed a slower latency to peak P2, suggesting less efficient processing of visual information at a relatively early stage (∼200 ms after stimulus onset). Moreover, controls showed a larger P2 amplitude to Go versus No‐go, indicating an early discrimination between conditions that was not seen in the FAS/PFAS group. Consistent with previous literature on tasks related to cognitive control, the control group showed a well‐defined, larger N2 to No‐go versus Go, which was not evident in the FAS/PFAS group. Both groups showed the expected larger P3 amplitude to No‐go versus Go, but this condition difference persisted in a late slow wave for the FAS/PFAS group, suggesting increased cognitive effort.

Conclusions:  The timing and amplitude differences in the ERP measures suggest that slower, less efficient processing characterizes the FAS/PFAS group during initial stimulus identification. Moreover, the exposed children showed less sharply defined components throughout the stimulus and response evaluation processes involved in successful response inhibition. Although both groups were able to inhibit their responses equally well, the level of neural activation in the children with FAS/PFAS was greater, suggesting more cognitive effort. The specific deficits in response inhibition processing at discrete stages of neural activation may have implications for understanding the nature of alcohol‐related deficits in other cognitive domains as well.
Actions and Interactions of Alcohol and Insulin‐Like Growth Factor‐1 on Female Pubertal Development
Authors: Dees W. Les , Srivastava Vinod , Hiney Jill K.
Published: August 2009

Alcohol (ALC) is a drug that is capable of disrupting reproductive function in adolescent humans, as well as immature rhesus monkeys and rats. Critical to determining the mechanism(s) of the effects of ALC on the pubertal process is to have a better understanding of the important events involved in the initiation of puberty. For years it has been hypothesized that there may be metabolic signals capable of linking somatic growth to the activation of the reproductive system at the time of puberty. In recent years it has been shown that insulin‐like growth factor‐1 (IGF‐1) is one such signal that plays an early role in the pubertal process. In this review, we will describe the actions and interactions of ALC and IGF‐1 on molecular and physiological processes associated with pubertal development.
Appropriateness of fresh‐frozen plasma usage in hospital settings: a meta‐analysis of the impact of organizational interventions
Authors: Damiani Gianfranco , Pinnarelli Luigi , Sommella Lorenzo , Farelli Valentina , Mele Luca , Menichella Giacomo , Ricciardi Walter
Published: August 2009

BACKGROUND: Transfusions of fresh‐frozen plasma (FFP) are a worldwide ever‐growing practice. The most advanced health care organizations, to guarantee high‐quality standards of interventions and safe procedures, should disseminate scientific evidence for promoting the appropriateness of transfusions and reducing avoidable risks.

STUDY DESIGN AND METHODS: We carried out a systematic review of scientific literature searching for studies focused on the implementation of different strategy of organizational interventions aimed at improving clinicians’ practice.

RESULTS: Of 915 studies, 10 articles were included in our meta‐analysis of risk of inappropriate transfusion after the implementation of an organizational intervention. The risk ratio of inappropriate transfusions before organizational interventions was 2.02 (95% confidence interval, 1.44‐2.84) compared with after interventions.

CONCLUSION: The organizational interventions showed a positive impact on the reduction of rates of inappropriate FFP transfusion episodes.
What about Design Newness? Investigating the Relevance of a Neglected Dimension of Product Innovativeness
Authors: Talke Katrin , Salomo Sören , Wieringa Jaap E. , Lutz Antje
Published: August 2009

In several industries, new products are very similar in functional features but compete on their unique design. Firms like Alessi, Apple, Bang & Olufsen, Dyson, or Kartell all follow a design‐driven innovation approach and use their products' visual appearance as the main mean for differentiation. In spite of this, design newness is never discussed among the dimensions of product innovativeness. Instead, conceptualizations of product innovativeness mostly focus on a product's technical newness or the changes it implies for the innovating firm or for the market it enters. This paper seeks to build an argument for why design newness should be considered as a dimension of product innovativeness. In addition to providing conceptual rationale, empirical evidence is offered on the influence of design newness on sales performance across a product's life cycle. To be able to put the findings into perspective, the performance effects of design newness are compared with those of technical newness. As several products exemplify that design newness and technical newness can go hand in hand, not only direct performance effects but also interaction effects between both newness dimensions are investigated. The arguments are tested on a sample of 157 new cars launched between 1978 and 2006 in Germany. The automobile industry is selected because of the strategic role of both technical and design aspects in product innovation. Putting a focus on this industry also has the advantage that historical information on car specifics and objective sales data over time are accessible. The results emphasize that both design and technical newness are important drivers of car sales. However, the effects differ widely across the product life cycle. While design newness has a positive impact right after the introduction and persists in strength over time, technical newness drives sales with a lagged effect and decreases toward the end of the life cycle. The test of a combined influence of design newness and technical newness on sales performance produces no significant results. These results open interesting avenues for future research on product innovativeness in general and design newness in particular. For management practice, the findings emphasize the importance of overall product innovativeness, clarify the different performance effects of design and technical newness across the product life cycle, and show the value of creating a unique visual product appearance to positively trigger product diffusion.
The Impact of NPD Strategy, Product Strategy, and NPD Processes on Perceived Cycle Time
Authors: Parry Mark E. , Song Michael , De Weerd‐Nederhof Petra C. , Visscher Klaasjan
Published: August 2009

Studies of new product development (NPD) have identified a variety of factors that influence cycle time, but most of these findings are based on case studies of individual firms. The few empirical studies that have attempted to examine the generalizability of these findings have tended to focus on one set of decisions (e.g., product strategy decisions) without considering the impact of organizational variables. To address this gap in the literature, this paper examines the impact on perceived cycle time of six variables that reflect a business unit's NPD strategy, NPD environment, product strategy, and NPD processes. The study also examines whether the impact of each of these antecedent variables is independent of the remaining variables. Contingency theory implies that cycle time performance will reflect the internal consistency of multiple contingencies and multiple structural characteristics. This implication is tested by evaluating the incremental explanatory power of two distance variables: one based on a theoretically defined ideal profile; and a second based on an empirically defined ideal profile. This analysis is important, because it permits a test of the proposition that understanding the pattern of contextual and structural variables adds additional insight to the understanding of cycle time performance. The analysis, based on data collected from 164 firms, indicates that the development of a formal NPD strategy, the creation of an appropriate climate for innovation, and the use of cross‐functional teams all contributed to improved perceptions of satisfactory cycle times. It was also found that executives in business units with broad product lines were less likely to perceive their cycle times as satisfactory. Contrary to expectations, an increasing emphasis on products involving breakthrough core processes was found to increase perceptions of satisfactory cycle times. Moreover, the use of heavyweight project managers had no significant impact on cycle time perceptions. The study also found no evidence to indicate that deviations from either a theoretically or an empirically defined ideal profile lengthen perceived cycle time.
Management Control and Strategic Renewal in the Front End of Innovation
Authors: Poskela Jarno , Martinsuo Miia
Published: August 2009

Should management control the front end of innovation in companies, and, if so, how? This paper examines the use of management control in the front end of innovation, how the different mechanisms of control are associated with generating strategic renewal, and what the moderating effect of technology and market uncertainty is. The front end of innovation has been characterized as highly uncertain and creative, thereby requiring high levels of freedom and independence for those executing front‐end activities. However, a certain amount of control appears necessary to secure the effective use of resources and the achievement of the company's long‐term objectives. The current findings of management control and its influence on performance in new product development context in general are conflicting. While many authors argue that behavioral control kills creativity, some others emphasize advantages of improved communication and coordination created by process formalization. Some authors stress the importance of setting specific and challenging strategic goals for development work, but some papers indicate that this inhibits creativity and learning. One challenge of interpreting the conflicting results of existing management control research in new product development context is that most studies treat the front‐end phase simultaneously with product development projects, thereby averaging the totally different characteristics of these two innovation phases. Studies that would have investigated management control in the front end of innovation are still scarce. This study develops a framework for management control in the front end of innovation and tests hypotheses on the relationship between different control mechanisms and achieving strategic renewal. The role of technology and market uncertainty as potential moderators of this relationship is investigated. Management control is covered through seven constructs: input control; front‐end process formalization; outcome‐based rewarding; strategic vision; informal communication; participative planning; and intrinsic task motivation. Strategic renewal is used as a front‐end performance indicator. Data from the front‐end phase of 133 new product development projects from different large and medium‐sized companies were collected and analyzed. A factor model was used to test the validity of the management control framework, and a moderated regression analysis was used for hypothesis testing. The results show that input control is positively associated with achieving strategic renewal in the front‐end phase. The results also confirm the importance of intrinsic task motivation of the front‐end group. Under high technology uncertainty, the use of outcome‐based rewarding or front‐end process formalization has a negative influence on strategic renewal.
2:1 Left to Right Interatrial Block and Other Effects of Ibutilide during Non‐isthmus‐Dependent Atrial Flutter
Authors: ZAMBITO PETER E. , PALMA EUGEN C.
Published: August 2009

The effects of ibutilide on non‐isthmus‐dependent atrial flutter (NIDAFL) and the left atrium are not completely known. We describe a case report of 2:1 left to right interatrial block as a result of ibutilide during NIDAFL. This is a 68‐year‐old man with history of right atrial flutter ablation who presented with recurrence of atrial flutter and underwent a diagnostic electrophysiology study. A 20‐pole catheter with 2–10‐mm spacing was used spanning the cavotricuspid isthmus to the midcoronary sinus. Morphology of the flutter waves and atrial activation sequence was recorded. Ibutilide was given to terminate the atrial flutter. During administration, 2:1 left‐to‐right interatrial block was seen. In addition, the cycle length of the flutter prolonged, yet the activation sequence did not change. Ibutilide terminated the flutter. During sinus rhythm, interatrial block was not seen. This case report illustrates an example of 2:1 left to right interatrial conduction block because of ibutilide during a non‐isthmus‐dependent atrial flutter.
Multiple Vector Impedance Measurements During Biventricular Pacing: Feasibility and Possible Implications for Hemodynamic Monitoring
Authors: VALZANIA CINZIA , ERIKSSON MARIA J. , HOLMSTRÖM NILS , JÄRVERUD KARIN , GADLER FREDRIK
Published: August 2009

Background:

Intracardiac impedance (ICZ) has been known to reflect contractile capacity of the heart, and a strong relationship has been documented between stroke volume and ICZ. In this pilot study, conducted in heart failure patients during implantation of a biventricular device, we investigated acute changes in multiple vector ICZ signals during different pacing modes, and whether ICZ can be used to monitor hemodynamic variations.

Methods:

Z1 and Z2 impedance signals were recorded in the right ventricle (RV), and between the left ventricle (LV) and RV, respectively, in 12 patients during four programming modes. ICZ signals were analyzed with respect to average and peak‐to‐peak (p2p) amplitude and systolic slope, and correlated with noninvasive hemodynamic and echocardiographic variables.

Results:

ICZ p2p amplitude decreased during LV stimulation both in Z1 and in Z2 configuration (P = 0.021 and P = 0.022 vs intrinsic conduction, respectively). No significant variations in average amplitude or systolic slope were observed. ICZ variables correlated directly with hemodynamic measures (r = 0.48, P < 0.05, between Z2 p2p amplitude and pulse pressure), LV ejection fraction (r = 0.32, P < 0.05, for Z1 average amplitude), RV ejection fraction (r = 0.75, P < 0.05, for Z1 p2p amplitude), and inversely with ventricular volumes.

Conclusions:

Variations in ICZ may be observed during different pacing modes and seem to correlate with hemodynamic and echocardiographic variables. Multiple vector ICZ measurement may be a feasible tool for hemodynamic assessment in patients treated with biventricular pacing.
Linear Radiofrequency Microcatheter Ablation Guided by Phased Array Intracardiac Echocardiography Combined with Temperature Decay
Authors: KEANE DAVID , HYNES BRIAN , LAMKIN ROBERT , HOUGHTALING CHRISTOPHER , ZHOU LI , ARETZ THOMAS , RUSKIN JEREMY
Published: August 2009

Background:

Fluoroscopy‐guided catheter placement is limited in its ability to determine electrode‐endocardial contact and involves radiation exposure. We hypothesized that (1) intracardiac echocardiography (ICE) would provide superior assessment of linear electrode contact compared to fluoroscopy and (2) slow temperature decay upon discontinuation of the radiofrequency current (time for temperature to fall 90% after a 10‐second test application of the radiofrequency current T90) would indicate optimal electrode‐myocardial contact.

Methods:

Sixty endocardial lesions were created in the atria and ventricles of six goats by simultaneous delivery of the radiofrequency current through two linear electrodes of a microcatheter with a central interelectrode thermocouple. Catheter placement was guided by fluoroscopy. A 7.5‐MHz ICE transducer in the right atrium or ventricle assessed electrode contact. T90 and previously reported parameters of electrode contact and lesion formation were recorded. Histomorphometry was performed on the lesions.

Results:

T90 was 4.27 ± 4.98 seconds. Lesion depth significantly correlated with ICE assessment of electrode contact (r = 0.56, P = 0.001); T90 upon radiofrequency current offset (r = 0.48, P = 0.008), impedance fall upon radiofrequency current onset (r = 0.37, P = 0.008), bipolar pacing threshold preablation (r =−0.56, P = 0.001), bipolar electrogram amplitude preablation (r = 0.43, P = 0.02), but not with fluoroscopic assessment of the electrode contact (r = 0.18, n.s.). For the prediction of achieving a lesion depth of >2 mm, a T90 of >4.0 seconds yielded a specificity of 86% and a sensitivity of 52%, ICE yielded a specificity and sensitivity of 58% and 68%, respectively, while the specificity and sensitivity of fluoroscopy were 26% and 68%, respectively. Both ICE and T90 provide additional clinical relevance during guidance of cardiac microcatheter ablation.
The Relationship Between Electrogram Cycle Length and Dominant Frequency in Patients with Persistent Atrial Fibrillation
Authors: SINGH SHELDON M. , HEIST E. KEVIN , KORUTH JACOB S. , BARRETT CONOR D. , RUSKIN JEREMY N. , MANSOUR MOUSSA C.
Published: September 2009

Introduction:
Sites of complex fractionated atrial electrograms (CFAE) with a short mean cycle length (MCL) and sites with a high dominant frequency (DF) have been advocated as targets for ablation in patients with persistent atrial fibrillation (AF). However, there are little data on the relationship between theses 2 markers. This study assessed the relationship between the DF and electrogram MCL after pulmonary vein (PV) isolation in patients with persistent AF.

Methods and Results:
A total of 44 patients with persistent AF were studied. Four‐second bipolar electrograms were obtained with a multielectrode mapping catheter at regions throughout the left atrium after isolation of the pulmonary veins, with analysis of the MCL and DF at each site. The DF was defined as the largest frequency peak within a 2.5‐ to 16‐Hz spectral profile generated with fast Fourier transformation of the electrogram. A total of 9,262 electrograms from the 44 patients were analyzed. The average MCL and DF post‐PV isolation were 135 ± 24 ms and 6.1 ± 0.6 Hz, respectively. There was a statistically significant but weak correlation between the MCL and DF (r = 0.21, P < 0.001). Additionally, analysis of this relationship within each patient did not demonstrate a strong correlation (range of r values per patient =−0.18 to 0.47).

Conclusions:
There is a poor correlation between the electrogram MCL and DF in patients with persistent AF. Ablation strategies targeting DF and those targeting CFAE are therefore unlikely to direct ablation toward similar left atrial sites. Comparative studies are necessary to determine the effectiveness of each strategy in guiding catheter ablation of persistent AF.
Examination of Intercostal Arteries with Transthoracic Doppler Sonography
Authors: Koyanagi Tetsuya , Kawaharada Nobuyoshi , Kurimoto Yoshihiko , Ito Toshiro , Baba Toshio , Nakamura Masanori , Watanebe Atsushi , Higami Tetsuya
Published: August 2009

Objective: There has been no study on the measurement of blood flow of the intercostal artery (ICA) or lumbar artery (LA) with the use of transthoracic Doppler sonography. Here, the method of the ICA depiction and flow measurement were described, and we suggested the clinical usage of this method. Methods: Twelve healthy subjects were examined. The performance of transthoracic Doppler sonography was approached from the back on lateral decubitus position. The intercostal artery was depicted by two‐dimension mode with color flow, and the inner diameter was measured. Peak systolic velocity (PSV), end‐diastolic velocity (EDV), velocity‐time integral (VTI), and heart rate (HR) were measured with pulsed Doppler, and the blood flow was calculated. Results: Bilateral ICAs and LAs from Th4 to L4 were measurable with this method. The PSV of Lt Th9 was the fastest at 43.3 ± 10.1 cm/sec and the PSV of the ICAs gradually decreased as distance from Th9 increased. As for the flow volume, the left Th11 was the greatest at 99.7 mL/min, and the flow volume of the ICA gradually decreased as distance from Th11 increased. The velocity and blood flow of right ICA tended to be lower than the left in the same spinal level. Conclusions: Evaluation technique of serial ICAs and LAs was shown. We think that it may be a clinically useful method in the study of spinal cord circulation in the repair of cases of descending thoracic or thoracoabdominal aortic aneurysm. (Echocardiography 2010;27:17‐20)
Tricuspid Regurgitation after Orthotopic Heart Transplantation
Authors: Kalra Nishant , Copeland Jack G. , Sorrell Vincent L.
Published: August 2009

Background: Tricuspid regurgitation (TR) is a relatively common abnormality in normal adults as well as after orthotopic heart transplantation (OHT). A few studies have shown reduction in the incidence of TR after OHT by total bicaval surgical anastomosis technique. Other studies reported no significant difference in the rates of TR between the standard and bicaval techniques. Objective: Evaluate and compare the degree of TR after OHT by standard and bicaval anastomosis techniques. Method: Echocardiograms from the first 56 consecutive patients that had the total bicaval surgical technique performed were retrospectively reviewed and compared with the last 57 consecutive patients who had the standard biatrial technique performed. Patients with adequate two‐dimensional and Doppler echocardiograms were included. Results: No statistical difference was observed for each grade of TR at both early and late time points. No significant difference was observed between the TR velocities of both biatrial and bicaval anastomosis patients at different periods. Conclusion: There appears to be no difference between the TR severity and TR velocity at early and late time points regardless of anastomotic technique. (Echocardiography 2010;27:1‐4)
The Correlation between Three‐Dimensional Vena Contracta Area and Aortic Regurgitation Index in Patients with Aortic Regurgitation
Authors: Chin Chih‐Hui , Chen Chung‐Huo , Lo Hung‐Shun
Published: August 2009

Objectives: The aims of this study are to explore the correlation between the three‐dimensional vena contracta (3D VC) area and the aortic regurgitation (AR) index and to determine AR severity using the 3D VC area. Background: The geometry of regurgitant jets is complex in patients with AR. The 3D VC area can be easily cropped using any plane and we can obtain the complex geometry of the VC area. Methods: Full‐volume three‐dimensional (3D) color flow datasets were generated using the trans‐thoracic parasternal approach. The AR jet could be well visualized and analyzed in three orthogonal planes using dedicated software. Results: We consecutively analyzed 77 AR patients with comprehensive 2D and 3D echocardiographic data. The 3D VC area increased proportionately with increasing AR severity using the AR index method (F = 86.1, P < 0.001) and correlated well with effective regurgitant orifice (P < 0.001). The cutoff value of the VC area was < 30 mm2 (sensitivity = 90% and specificity = 88%) for predicting mild AR and > 50 mm2 (sensitivity = 92% and specificity = 87%) for predicting severe AR. Conclusion: 3D color flow VC area measurement provides a simple and accurate method for assessing the severity of AR. (ECHOCARDIOGRAPHY 2010;27:161‐166)
Association of Bicuspid Aortic Valve Morphology and Aortic Root Dimensions: A Substudy of the Aortic Stenosis Progression Observation Measuring Effects of Rosuvastatin (ASTRONOMER) Study
Authors: Jassal Davinder S. , Bhagirath Kapil M. , Tam James W. , Sochowski Randall A. , Dumesnil Jean G. , Giannoccaro Peter J. , Jue John , Pandey A. Shekhar , Joyner Campbell D. , Teo Koon K. , Chan Kwan L.
Published: August 2009

Background: Bicuspid aortic valve (BAV) is the leading cause of aortic stenosis in patients younger than the age of 50. A classification scheme of BAVs is based upon leaflet orientation: Type I (fusion of right and left coronary cusps) and Type II (fusion of right and noncoronary cusps). The correlation between BAV leaflet orientation and aortic root pathology however remains ill defined. Objective: The objective was to describe a potential relationship between BAV leaflet morphology and aortic root measurements in the ASTRONOMER study, a multicenter study to assess the effect of rosuvastatin on the progression of AS. Methods: BAV morphology was classified as Type I or Type II orientation based on the parasternal short‐axis view. Echo measurements including left ventricular and aortic root dimensions were obtained. Results: The study population included 89 patients (56 ± 11 years; 44 males). There were 63 patients with Type I and 26 patients with Type II BAV. Baseline demographics, hemodynamics, and left heart dimensions were similar between both groups. Patients with Type I BAV had larger aortic annulus and ascending root dimensions compared to those patients with Type II BAV (P < 0.05). Conclusion: In patients with mild to moderate aortic stenosis due to a BAV, the presence of Type I valve orientation was associated with significantly greater aortic root parameters compared to Type II valve orientation. (ECHOCARDIOGRAPHY 2010;27:174‐179)
A New Website for the Society for Visual Anthropology: http://societyforvisualanthropology.org/
Authors: HENNESSY KATE , CAMPBELL CRAIG
Published: September 2009

ABSTRACT  In 2008, the Society for Visual Anthropology reconceived and redesigned its website to create a communications infrastructure that is sustainable, flexible, aesthetically engaging, and responsive to the needs of diverse users. The site utilizes blogging and social‐media principles to more efficiently distribute information and to promote and archive the activities of the society's annual Film, Video, and Interactive Media Festival and Visual Research Conference.
One Step Fabrication of MgO Solid and Hollow Submicrometer Fibers Via Electrospinning Method
Authors: Hota Garudadhwaj , Sundarrajan Subramanian , Ramakrishna Seeram , WunJern Ng
Published: August 2009

Poly (vinyl pyrrolidone) (PVP)/magnesium acetate composite fibers were prepared by electrospinning technique via sol–gel process. Magnesium oxide (MgO) submicrometer fibers (solid) and tubes (hollow) with diameter in the range of 100–400 nm were successfully prepared by calcinations of PVP/magnesium acetate composite fibers. The MgO submicrometer fibers and tubes were characterized using SEM, X‐ray diffraction (XRD), and TEM analytical techniques. XRD results showed that the crystalline cubic MgO fibers were formed and their crystallinity was highly influenced by the calcination temperature. SEM and TEM results clearly showed the formation of hollow submicrometer tubes and solid submicrometer rods/fibers. The exact mechanism of the formation of MgO submicrometer tubes is not clear and further studies are needed to gain insight into the mechanism of formation.
Processing Conditions and Aging Effect on the Morphology of PZT Electrospun Nanofibers, and Dielectric Properties of the Resulting 3–3 PZT/Polymer Composite
Authors: Mensur Alkoy Ebru , Dagdeviren Canan , Papila Melih
Published: August 2009

Lead zirconate titanate (PZT) nanofibers are obtained by electrospinning a sol–gel based solution and polyvinyl pyrrolidone (PVP) polymer, and by subsequent sintering of the electrospun precursor fibers. The average diameter of the precursor PZT/PVP green fibers has increased with the aging of the precursor solution along with an increase in the viscosity. Bead‐free uniform green PZT/PVP fibers were collected at about an ∼230 nm average fiber diameter using a 28 wt% PVP ratio solution with a viscosity of 290 mPa. Shrinkage of 40% was recorded on the fiber diameter after sintering. The X‐ray diffraction pattern of the annealed PZT fibers exhibits no preferred orientation and a perovskite phase. Preparation of 3–3 nanocomposites by the infusion of polyvinylester into the nanofiber mat facilitates successful handling of the fragile mats and enables measurements of the dielectric properties. The dielectric constant of the PZT/polyvinylester nanocomposite of about 10% fiber volume fraction was found to be fairly stable and vary from 72 to 62 within the measurement range. The dielectric loss of the composite is below 0.08 at low frequencies and reaches a stable value of 0.04 for most of the measured frequencies.
Substrate Effect on the Magnetoelectric Behavior of Pb(Zr0.52Ti0.48)O3 Film‐On‐CoFe2O4 Bulk Ceramic Composites Prepared by Direct Solution Spin Coating
Authors: Wang Jing , Wang Lianjun , Liu Guanghua , Shen Zhijian , Lin Yuanhua , Nan C. W.
Published: August 2009

Magnetoelectric (ME) composite structures of Pb(Zr0.52Ti0.48)O3 (PZT) and CoFe2O4 (CFO) were prepared by directly growing PZT films on highly dense CFO ceramics via a simple solution spin coating, rather than by conventional high‐temperature cofiring. An obvious ME response, which had the same bias‐dependent trend as the piezomagnetic coefficient of CFO ceramics, was observed in such film‐on‐bulk ceramic composites. It was found that the PZT films showed a good ferroelectric feature, and the ME response of the composites strongly depended on the resistivity of the CFO ceramics as both a substrate and a bottom electrode. The results suggest plenty of room for further enhancing the ME response of such films‐on‐ceramic substrate composites.
The Tetragonal‐Monoclinic Transformation in Zirconia: Lessons Learned and Future Trends
Authors: Chevalier Jérôme , Gremillard Laurent , Virkar Anil V. , Clarke David R.
Published: August 2009

Zirconia ceramics have found broad applications in a variety of energy and biomedical applications because of their unusual combination of strength, fracture toughness, ionic conductivity, and low thermal conductivity. These attractive characteristics are largely associated with the stabilization of the tetragonal and cubic phases through alloying with aliovalent ions. The large concentration of vacancies introduced to charge compensate of the aliovalent alloying is responsible for both the exceptionally high ionic conductivity and the unusually low, and temperature independent, thermal conductivity. The high fracture toughness exhibited by many of zirconia ceramics is attributed to the constraint of the tetragonal‐to‐monoclinic phase transformation and its release during crack propagation. In other zirconia ceramics containing the tetragonal phase, the high fracture toughness is associated with ferroelastic domain switching. However, many of these attractive features of zirconia, especially fracture toughness and strength, are compromised after prolonged exposure to water vapor at intermediate temperatures (∼30°–300°C) in a process referred to as low‐temperature degradation (LTD), and initially identified over two decades ago. This is particularly so for zirconia in biomedical applications, such as hip implants and dental restorations. Less well substantiated is the possibility that the same process can also occur in zirconia used in other applications, for instance, zirconia thermal barrier coatings after long exposure at high temperature. Based on experience with the failure of zirconia femoral heads, as well as studies of LTD, it is shown that many of the problems of LTD can be mitigated by the appropriate choice of alloying and/or process control.
Mitochondrial accumulation of APP and Aβ: significance for Alzheimer disease pathogenesis
Authors: Pavlov Pavel F. , Petersen Camilla Hansson , Glaser Elzbieta , Ankarcrona Maria
Published: September 2009

Introduction

Age and AD related mitochondrial changes in brain and peripheral tissues

Effect of APP accumulation on mitochondrial function

Mitochondria as a target and mediator of Aβ toxicity

Conclusions

Accumulating evidence suggest that alterations in energy metabolism are among the earliest events that occur in the Alzheimer disease (AD) affected brain. Energy consumption is drastically decreased in the AD‐affected regions of cerebral cortex and hippocampus pointing towards compromised mitochondrial function of neurons within specific brain regions. This is accompanied by an elevated production of reactive oxygen species contributing to increased rates of neuronal loss in the AD‐affected brain regions. In this review, we will discuss the role of mitochondrial function and dysfunction in AD. We will focus on the consequences of amyloid precursor protein and amyloid‐β peptide accumulation in mitochondria and their involvement in AD pathogenesis.
Bio‐degradation of a resorbable collagen membrane (Bio‐Gide®) applied in a double‐layer technique in rats
Authors: Kozlovsky Avital , Aboodi Guy , Moses Ofer , Tal Haim , Artzi Zvi , Weinreb Miron , Nemcovsky Carlos E.
Published: August 2009

Objective: The aim of this study was to evaluate histologically the bio‐degradation of two layers of Bio‐Gide® (BG) membrane, as compared with that of a single layer.

Material and methods: Two circular calvarial bony defects, 5 mm in diameter, were made in 24 Wistar rats. BG membrane, labeled with biotin, was cut into 5‐mm‐diameter disks, and placed in defects either as a mono‐layer membrane (MLM) or as a double‐layer membrane (DLM). Rats were sacrificed after 4 or 9 weeks and histology was performed. Membranes were stained with horseradish peroxidase‐conjugated streptavidin and aminoethyl carbazole as a substrate for detection of biotinylated collagen. The area of collagen and thickness of the residual membranes were measured by image analysis software. Statistical analysis was performed using the non‐parametric Wilcoxon's signed‐ranks test.

Results: At 4‐week collagen area per measurement window within the DLM sites (0.09±0.05 mm2) was significantly greater (P<0.01) than that in the MLM sites (0.047±0.034 mm2). At 9 weeks, the collagen area was also greater in the DLM sites (0.037±0.026 mm2) compared with that of the MLM sites (0.025±0.016 mm2); however, this difference did not reach statistical significance. The rate of membrane degradation, calculated as percent membrane lost compared with baseline, was similar for the DLM and MLM at both time points (∼60% at 4 weeks and ∼80% at 9 weeks). In addition, the residual DLM thickness at 4 weeks (475.5±73.77 μm) was significantly (P<0.01) greater than that of MLM (262.38±48.01 μm). At 9 weeks, membrane thickness was also greater in the DLM sites (318.22±70.45 μm) compared with that of the MLM sites (183.32±26.72 μm); however, this difference did not reach statistical significance. The reduction in thickness between 4 and 9 weeks was 30% for MLM and 33% for DLM.

Discussion: The use of a double layer of BG membrane results in a barrier of increased collagen area and thickness, compared with application of a single layer.
Patient‐centered outcome of immediately loaded implants in the rehabilitation of fully edentulous jaws
Authors: Dierens Melissa , Collaert Bruno , Deschepper Ellen , Browaeys Hilde , Klinge Björn , De Bruyn Hugo
Published: August 2009

Introduction: Edentulism often involves functional, esthetic, phonetic and psychological problems.

Objectives: To evaluate patient‐centered outcomes of full‐arch screw‐retained rehabilitation on immediately loaded implants.

Material and methods: Fifty patients treated with Astra Tech™ implants answered self‐administered questionnaires on a visual analogue scale (VAS) 100 mm scale or with multiple‐choice or open questions: at baseline, 1 week, 3 or 6 months and 1 year. Changes of VAS in time were analyzed using mixed models for repeated measures, adjusting for gender, age and jaw; comparison of cross‐sectional parameters between jaws was performed with the Mann–Whitney U‐ or χ2‐test, all at the 0.05 significance level.

Results: The median calculated general satisfaction score increased from 40.25 (mean=40.9; SD=23.82; range=0–95) at baseline to 98.25 (mean=95.3; SD=6.68; range=74–100) after 1 year. Overall comfort, eating comfort, speaking comfort and perceived esthetics improved significantly within 1 week after surgery and immediate provisionalization. This did not change significantly until the final bridge was installed after 3 months (mandible) or 6 months (maxilla), when a further significant improvement was demonstrated. The most common postoperative complication was swelling, especially in the maxilla. The importance of one‐stage surgery and immediate loading was rated very high by patients before treatment, especially in the mandible. The main reason for choosing fixed prosthetics was eating comfort. Phonetics and esthetics were more important in the maxilla than in the mandible.

Conclusion: Immediate full‐arch rehabilitation yeilds an instant significant improvement in general patient satisfaction and self‐perceived factors related to comfort, function and esthetics. Eating comfort is the main concern for the patient and shows the highest improvement. Postoperative complications are limited and patients considered immediate loading important.
Microflora associated with successful and failed orthodontic mini‐implants
Authors: Apel Stephanie , Apel Christian , Morea Camillo , Tortamano André , Dominguez Gladys Cristina , Conrads Georg
Published: August 2009

Objectives: Mini‐implants are used for orthodontic bone anchorage. The reasons for a potential instability or loss of the mini‐implants during treatment are multiple. Among other factors, colonization of implants with pathogenic bacteria is discussed. Therefore, the microflora associated with successful and failed mini‐implants has been screened.

Material and methods: A total of 76 mini‐implants collected from 25 patients were observed during regular orthodontic treatment. Bacterial samples of eight failed and – exemplarily – four successful (control) cases were subjected to a universal Bacteria‐directed real‐time quantitative polymerase chain reaction for quantification in combination with a microarray‐based identification of 20 selected species.

Results: The failure rate in the present investigation was 10.5%. The bacterial analysis did not reveal any major difference in the total amount or species composition between control and failed mini‐implants. However, Actinomyces viscosus was found in four (100%) and Campylobacter gracilis in three (75%) stable controls, whereas both species were rarely found (12.5%) in failed implants.

Conclusions: In the present study, the peri‐implant sulcus surrounding failed orthodontic mini‐implants did not show a specific aggressive bacterial flora.
Bone augmentation ability of autogenous bone graft particles with different sizes: a histological and micro‐computed tomography study
Authors: Kon Kazuhiro , Shiota Makoto , Ozeki Maho , Yamashita Yasuo , Kasugai Shohei
Published: August 2009

Objectives: The purpose of this study was to investigate the augmentation process and ability of autogenous bone graft particles of two different sizes in a vertical augmentation chamber.

Material and methods: The cranial bones of 24 rabbits were used. Two polytetrafluoroethylene chambers were filled with harvested bone from tibia with small bone (SB; 150–400 μm) and large bone (LB; 1.0–2.0 mm) of the same weight. Animals were sacrificed after 1, 2, 4 and 8 weeks. The samples were analyzed by micro‐computed tomography (micro‐CT) for quantitative analysis, and embedded in polyester resin as non‐decalcified specimens for histological analysis. Total bone volume (TBV), bone height (BH) and distribution of bone structure were calculated by micro‐CT.

Results: Micro‐CT evaluation and histology revealed a significant difference between the investigated specimens. TBV and BH of SB decreased to about 50% of the initial situation, and there was a statistically significant difference between 1 and 8 weeks. In contrast, TBV and BH of LB were almost retained at all experimental time points. Significant differences in TBV and BH were also observed between LB and SB at 8 weeks. Bone volume of SB decreased predominantly in the upper half of the chamber at 4 and 8 weeks. In the histological observations, SB showed favorable new bone formation and rapid bone resorption in a time‐dependent manner during the entire experimental period. However, LB exhibited favorable morphological stability and continued new bone formation.

Conclusion:

SB follows a smooth osteogenic process, whereas it is not effective in volume augmentation. LB is superior to SB in augmentation ability.