bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wide Variations in Energy Delivery Using an Impedance-Controlled Algorithm in Bipolar Radiofrequency Ablation: Evidence against Fixed Time Ablation
Authors: Melby Spencer J. , Zierer Andreas , Voeller Rochus K. , Lall Shelly C. , Bailey Marci S. , Moon Marc R. , Schuessler Richard B. , Damiano Ralph J. 
Published: May 2008

Objective Bipolar radiofrequency ablation recently has been used to replace many of the incisions of the Cox-Maze procedure in the surgical treatment of atrial fibrillation. The unique aspect of this technology is that it uses an algorithm based on changes in tissue conductance to determine the energy required to achieve a transmural lesion instead of relying on predetermined time and/or temperature criteria to determine ablation duration, as with most other ablation technologies. The purpose of this study was to determine variations in the different parameters of ablation needed to create transmural lesions in human atria. Methods Initial impedance, total energy, temperature, and ablation time were measured in 38 patients undergoing surgery, using an impedance-controlled bipolar radiofrequency device (AtriCure Isolator, Cincinnati, OH). Lesions were categorized into the following groups: right atrial free wall, left atrial free wall, atrium up to mitral valve annulus, atrium up to tricuspid valve annulus, and right or left pulmonary veins. Results There was a wide range of initial impedance (32.3 to 760.7 Ohms), and this correlated with total energy delivered (r = −0.31, P = 0.002). Ablation times varied widely (2.0 to 29.9 seconds) and were longer on left atrial structures than right (P < 0.005) and shortest near the tricuspid annulus (P < 0.001). Mean tissue temperature 1 mm from the electrode was only 45.7 ± 7.8°C (range, 23.7°C to 69.3°C). Conclusions Bipolar ablation of different atrial structures required widely different amounts of energy and ablation times, probably as the result of the inhomogeneity of atrial geometry and tissue impedance. These data cast doubt on the efficacy of any fixed-time or temperature ablations in the clinical setting.
Beating Heart Direct Left Atrial Access Balloon Cryoablation: Safety and Efficacy of Pulmonary Vein Isolation in an Ovine Model
Authors: Gammie James S. , Yankey G Kwame , Nolan Timothy , Wu Z. Jon , Dickfeld Timm , Cartier Catherine , Tremblay Andre , MacNeil Timothy P. , Burke Allen , Griffith Bartley P. 
Published: May 2008

Objective Clinical experience with endocardial cryoablation for the surgical treatment of atrial fibrillation has demonstrated safety and efficacy. Direct access to the left atrium via a thoracoscopic or pericardial approach with a balloon-tipped cryoablation catheter might facilitate endocardial cryoablation on the beating heart. We investigated the ability of a novel cryoballoon to produce endocardial pulmonary vein ostial cryolesions on the beating heart in a large-animal model. Methods Six sheep underwent small left thoracotomy. A 10.5F catheter with a 23-mm cryoballoon was inserted directly into the left atrium under fluoroscopic and intracardiac echo (ICE) guidance. Cryoablation of the pulmonary vein ostia was performed. Animals were killed at 14 days. Pulmonary venous electrical isolation was assessed immediately before the animals were killed. Results All animals survived balloon cryoablation with no periprocedural complications. Balloon occlusion was well tolerated hemodynamically, with minimal change in blood pressure (–4 ± 6 mm Hg systolic BP) and no change in heart rate. ICE demonstrated an absence of intracardiac air or ice embolization during ablation. Mean balloon temperature was −67 ± 8°C. All animals were neurologically intact after the procedure. Five of 6 (83%) veins exhibited circumferential exit block. Phrenic nerve function was intact in all animals. On gross inspection, all lesions were circumferential and continuous without evidence of endocardial thrombus. Pathology confirmed circumferential transmurality in all treated veins. Conclusions Direct left atrial access cryoballoon ablation was effective for isolating pulmonary veins. This technology may be an important component of a minimally invasive beating heart CryoMaze procedure for the treatment of atrial fibrillation.
Robotic-Assisted Lung Resection for Malignant Disease
Authors: Anderson Casandra A. , Hellan Minia , Falebella Andres , Lau Clayton S. , Grannis Fredric W. , Kernstine Kemp H. 
Published: May 2008

Objective There have been few reports of the use of robotic surgery to resect lung malignancies. Feasibility and safety of robotic lung resection for malignant lung lesions will be assessed by performing a retrospective analysis. Methods Between September 2004 and November 2006, 21 patients (11 male and 10 female patients) underwent robotic lung resection. Twenty resections were performed for primary nonsmall cell lung cancer and two for metastatic lesions. One patient had bilateral resections for two primary tumors. Fourteen lobectomies, five segementectomies, one wedge resection, and two bilobectomies were performed. Seventy-two percent of operative procedures included mediastinoscopy and/or bronchoscopy at the time of resection. Results Thirty-day mortality and conversion rate was 0%. The median operating room time and estimated blood loss was 3.6 hours and 100 mL, respectively. The median intensive care unit and total length of hospital stays were 2 and 4 days, respectively. Chest tubes were removed after a median of 2.0 days. The complication rate was 27%, which included atrial fibrillation, need for postoperative bronchoscopy, and pneumonia. The median tumor size and number of lymph nodes harvested was 2.3 cm and 16, respectively. All resection margins were negative. Median follow-up time was 9.8 months, with no local recurrences at this time. Conclusion Robotic lung resection appears safe and feasible and allows for significant lymph node retrieval, offers short hospital stays and low morbidity for patients undergoing surgical resection of lung malignancies. Future studies are needed to define the role of robotic surgery in lung cancer treatment.
Efficacy of Intramyocardial Injection of Angiogenic Cell Precursors for Ischemic Cardiomyopathy
Authors: Arom Kitipan V. , Ruengsakulrach Permyos , Jotisakulratana Vibul 
Published: May 2008

Introduction The objective of this study is to determine the efficacy of intramyocardial angiogenic cell precursors (ACPs) injection in ischemic cardiomyopathy (ICM). Methods Twenty-five ICM patients (cell group) underwent intramyocardial ACPs injection. Seventeen ICM patients (control group) treated by medical means were matched with cell group. There was no statistically significant difference between cell and control groups in relation to left ventricular ejection fraction (LVEF) and comorbidities. In the cell group, mean age was 58.4 ± 13.7 years. Mean LVEF was 26.1% ± 7.4%. New York Heart Association (NYHA) class was 2.9 ± 0.6. The ACPs were derived and expanded from autologous blood. The number of cells before injection was 27.4 ± 18.8 million cells. The cells were injected into the nonviable myocardium and hypokinetic segments in the cell group. Results There was no new ventricular arrhythmia. NYHA was improved by 0.9 ± 1.0 (P < 0.001) at 229.9 ± 98.8 days. Six-minute walk test and quality of life assessed by short form-36 improved in the cell group. LVEF was improved in 72% of patients (18 of 25). LVEF improved by 6.4 ± 9.9 points % (P = 0.003) at 290.4 ± 210.3 days. The percentage of infarction area decreased 21.9 ± 17.4 points % at 159 ± 54 days postoperatively. There was no significant improvement of NYHA and LVEF in the control group. Conclusions For this efficacy study, the NYHA class, quality of life, and six-minute walk test were improved after cell transplantation. The LVEF was also significantly improved in the cell treated group.
Tension Measurement of Artificial Chordae Tendinae Implanted between the Anterior Mitral Valve Leaflet and the Left Ventricular Apex
Authors: Bajona Pietro , Zehr Kenton J. , Liao Jun , Speziali Giovanni 
Published: May 2008

Objective A newly developed surgical technique allows implantation of artificial chordae tendinae between a mitral valve leaflet and the left ventricular (LV) apex in a closed-chest, off-pump mitral valve repair operation. However, this orientation causes tension vectors on the mitral valve leaflet in a different direction than those of native chordae. The purpose of this study was to investigate the relationship between systolic LV pressure and the tension of artificial chordae secured at the ventricular apex to assess if the altered tension vectors on the mitral leaflet resulted in excessive stress on the chordae/leaflet system. Methods Freshly harvested porcine mitral valves were suspended in a mechanical LV simulator. Two 5-0 Gore-Tex sutures were secured to the free edge of the middle scallop of the anterior leaflet adjacent to the insertion point of two major native chordae. The native chordae were then cut. A simulator pump was activated at different pressure levels, and the tension of the artificial chordae was measured with a digital tensiometer during several cardiac cycles. Results The numerical relationship between chordal tension (in Newtons, N) and LV pressure (in mm Hg/100) averaged at 0.8 (range 0.6–1.05). This tension/pressure relationship was similar in order of magnitude and range to that measured in native chordae in previously published studies. Conclusions In this in vitro model, orienting artificial chordae in a direction mimicking implantation between the valve and the LV apex does not result in excessive tension stress on either the chordae or the mitral leaflet.
TDI Based Automotive Seating: Solutions for Enhancing Foam Durability
Authors: van Eetvelde Els , Banner Carol , Cenens Jos , Chin Steven 
Published: May 2008

Improving the comfort and durability properties of automotive seating is an increasingly important issue within the global automotive seating industry. The technology for enhancing the comfort properties of polyurethane foams is one of the major needs of seating foam manufacturers and seat producers, whose focus is both foam density reduction and overall weight reduction of car seats. Shell Chemicals has therefore embarked on a fundamental program, focusing on the foam formulation durability relation of TDI-based foam grades. The study consists of a thorough investigation of the influence of independent formulation variables such as raw materials composition, water level and ancillary chemicals levels on foam processing and durability performance. A statistics driven experimental approach (central composite and full factorial designs) helped to increase the predictive power of the outcome, concerning overall mechanical foam properties and comfort performance in particular.
HFC-365mfc Blends: Status and Development as Blowing Agent for High Performance Insulation Foams
Authors: Zipfel Lothar , Dournel Pierre 
Published: May 2008

The recent developments confirm that HFC-365mfc is a very attractive blowing agent option, especially if we consider the various blends which have been developed to meet customers needs, for example non-flammability in a blend withHFC-134a or k-value improvement for hydrocarbon blown foams. The non-flammable blend HFC-365mfc/134a is an option for the construction market, notably for systems, for spray and for pour-in-place foams and is a direct replacement for HCFC-141b; as this blend is a mixture, there is an important difference compared to HCFC-141b. The special behavior during storage and handling will be explained, including details regarding its safety status.We will report our experience for a safe application and about new results in foams. For cost-drive markets, where explosively flammable options are acceptable, blends of HFC-365mfc with hydrocarbons are an attractive way to improve the k-value of foams. This paper will report the outstanding versatility of HFC-365mfc to provide the construction foam industry with a solution for all markets. The full commercialization of HFC-365mfc is scheduled for the end of the year 2002.
Effects of interaction design in digital libraries on user interactions
Authors: Zhang Xiangmin , Li Yuelin , Liu Jingjing , Zhang Ying 
Published: May 2008

PurposeThis study aims to investigate the effects of different search and browse features in digital libraries (DLs) on task interactions, and what features would lead to poor user experience.Design/methodology/approachThree operational DLs: ACM, IEEE CS, and IEEE Xplore are used in this study. These three DLs present different features in their search and browsing designs. Two information‐seeking tasks are constructed: one search task and one browsing task. An experiment was conducted in a usability laboratory. Data from 35 participants are collected on a set of measures for user interactions.FindingsThe results demonstrate significant differences in many aspects of the user interactions between the three DLs. For both search and browse designs, the features that lead to poor user interactions are identified.Research limitations/implicationsUser interactions are affected by specific design features in DLs. Some of the design features may lead to poor user performance and should be improved. The study was limited mainly in the variety and the number of tasks used.Originality/valueThe study provided empirical evidence to the effects of interaction design features in DLs on user interactions and performance. The results contribute to our knowledge about DL designs in general and about the three operational DLs in particular.
Leaders as facilitators of individual and organizational learning
Authors: Amy Amy H. 
Published: May 2008

PurposeThe organizational learning and learning organization literatures lack empirical support in delineating the role leaders play in fostering or hindering learning. This study aims to build upon previous research on facilitative leadership in learning organizations to consider how leaders contribute to and detract from learning at the individual and organizational levels in the corporate context.Design/methodology/approachPreliminary survey research confirmed that the Fortune 500 company being considered for the study was perceived as a learning organization by its employees. The study then proceeded with critical incident interviews with managers and their direct reports, resulting in a cross‐case content analysis of four categories: triggers, beliefs, behaviors, and outcomes, which prompted the development of a preliminary model of the learning process depicted by participants.FindingsThe findings revealed that learning leaders have several distinct characteristics and skills, but the participants gave the most emphasis to emotionally intelligent communication, a prominent feature of facilitative leadership.Research implications/limitationsThe study represents the perceptions of participants within a particular context at a specific time. Future research could include longitudinal, cross‐cultural studies that focus on communication processes related to learning.Practical implicationsThe study confirmed the importance of facilitative leadership while highlighting both cognitive and emotional aspects of learning. It also pinpointed mechanisms for institutionalizing learning.Originality/valueThe study offers empirical support for the centrality of facilitative leadership while pinpointing communication competence and emotional intelligence as essential aspects of effective learning leadership.
Employee justice perceptions and coworker relationships
Authors: Forret Monica , Sue Love Mary 
Published: May 2008

PurposeThe purpose of this investigation is to explore whether perceptions of organizational justice are related to coworker trust and morale. As jobs have become more broadly defined and collaboration with colleagues has become increasingly important for accomplishing work, coworker relationships are especially critical to manage effectively.Design/methodology/approachSurvey packets were distributed to 364 non‐supervisory employees at six small companies in a large Midwestern city in the USA. Useable surveys were returned from 264 respondents for a response rate of 72 percent.FindingsThe results showed that distributive, procedural, and interactional justice perceptions are related to perceptions of coworkers. The distribution of rewards, organizational policies and procedures, and interpersonal treatment by supervisors are related to coworker trust and morale.Research limitations/implicationsThis study was a cross‐sectional field study with the data collected at one point in time, precluding statements regarding causality. In addition, common method variance is a concern given the use of a self‐report survey.Practical implicationsThe results highlight the importance of fairness in rewards, procedures, and treatment for productive coworker relationships. Suggestions are provided for managers to enhance perceptions of distributive, procedural, and interactional justice in the workplace.Originality/valuePrior research on justice has focused primarily on individual and organizational outcomes. The study adds to this research base by examining whether perceptions of justice are associated with the quality of coworker relationships.
Tmsuk/Microsoft collaboration on robotic software
Authors: Kusuda Yoshihiro 
Published: May 2008

PurposeThis paper aims to report the collaboration between Microsoft and Tmsuk and describe the possible impact on the development of robotics software and the robot industry for the future.Design/methodology/approachThe paper gives an insight into the collaboration, based on an interview with the CEO of Tmsuk.FindingsMicrosoft will be one step ahead in the robotic software standardization race. Tmsuk will evaluate the performance in the real world applications.Practical implicationsTmsuk will evaluate Microsoft's Robotic Studio for its “practical” robotic applications and feed its findings back to Microsoft. The outcome is worth watching.Originality/valueMicrosoft Robotic Studio is the first robotic software development kit and Tmsuk is trying to prove it by its real world expertise. This is the first attempt to apply Micro Robotics Studio to practical applications in the real world.
Development of an omni‐directional mobile robot using traveling waves based on snail locomotion
Authors: Nakamura Taro , Satoh Kuniaki 
Published: May 2008

PurposeThe snail moves by propagating traveling waves from tail to head. If it is possible to propagate a traveling wave in many directions, an omni‐directional mobile robot could be realized. The purpose of this paper is to develop an omni‐directional mobile robot using the locomotion mechanism of the snail and to study the basic properties of the robot.Design/methodology/approachA unit for mobile robot was developed to generate the traveling wave based on the snail. The omni‐directional mobile robot is composed of eight units arranged in a circular shape and each abutting unit is connected by a spring. The robot generates a traveling wave by elongation and contraction of the units and realizes an omni‐directional locomotion.FindingsIt was confirmed that the robot moves using the traveling wave locomotion. Furthermore, the locomotion experiment confirmed that the robot moved in the expected direction with reasonable accuracy.Originality/valueThis paper proposes a new omni‐directional mobile mechanism using traveling wave based on a snail locomotion. Since the locomotion mechanism of the snail involves moving a larger area than is the case with other creatures, it is able to move not only on irregular ground such as swamps, but also on walls and ceilings. Hence, it is thought that this robot could be applied to the inspection of walls.
The institutional dynamics of homelessness
Authors: De Venanzi Augusto 
Published: May 2008

PurposePrevious research has made it clear that homelessness is a social condition that finds its origins in structural causes such as poverty, lack of affordable housing, chronic unemployment, and reductions in welfare support. However, in the author's view, the exclusive focus upon these structural variables fails to provide a comprehensive account of the social forces that contribute to and shape the homeless experience. The paper's aim is to contend that homelessness can also be viewed as the result of continued subordinate institutional experiences.Design/methodology/approachThe present paper examines in depth some of the inner practices of various normative institutions, namely morality, family, and the prison and uncover the ways in which they operate in producing acute states of social and moral disempowerment, and how they affect the faculties of subordinate members to competently fend for themselves in the wider society. It relies on a set of concepts coined by authors such as E. Goffman, M. Douglas, P. Boss, and M. Foucault in looking at the incapacitating nature of the aforementioned institutions. The study compares homelessness in two national contexts – that of the USA and Japan – in aiming to demonstrate that different institutional contexts tend to produce different patterns of homelessness. The research employs both secondary quantitative and secondary qualitative data. The quantitative data are used to establish the association of homelessness and subordinate institutional experience, the quantitative to illustrate the human experience of being homeless and to present cases that illustrate the “continuity chains” formed by those experiences.FindingsThe paper finds that different institutional settings will produce different patterns of homelessness.Originality/value –The institutional approach to homelessness advocated opens new avenues of concern and research in both the comprehensive understanding and the acting upon this vital problematic.
Strong, aware, and unequal
Authors: Juntti‐Henriksson Ann‐Kristin 
Published: May 2008

PurposeThe overall purpose of this paper is to study gender and equality‐related issues by exploring gender functions in the northernmost borderland of Sweden (the Tornedalen area). The study focuses on women's views of their own lives and how local culture may shape their identity.Design/methodology/approachBy analysing a large number of women's narratives through approaching feminist poststructuralism, the analysis focuses on gender relations and how women have adapted their lives according to the norms of the local society. The study involves a historical perspective from the middle to the late twentieth century. This includes transitions from an almost exclusively rural to a more urbanized life (within the countryside) and from a time when almost all women were full‐time housewives to a time when this has become a rarity.FindingsThe traditional culture in Tornedalen still existed in the late 1990s with pressure coming from the older generations to maintain traditional gender functions. From a feminist poststructuralist perspective, competing discourses affects the identity of the Tornedalen woman. Such competing discourses lead to, for example, women being impressed by masculine men who dominate the family whilst also, seemingly, expressing concern for equality issues. Many common gender identity characteristics also exist, such as (a feeling of) being strong (to be able to live in Tornedalen) and (a feeling of) being very much aware of (and claiming) local gender inequality. Originality/value – The paper provides new knowledge as to how inequality may persist in (a) local area(s) ruled by traditional norms. It also provides insights into women's lives and how identities evolve in (a) small local society(ies).