bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hemostatic Control of Coronary Arteries with Poloxamer 407 Reverse-Thermal Polymer during Off-Pump Coronary Artery Bypass Surgery in a Pig Model
Authors: Cohn William E. , Tuzun Egemen , Simonak Ryan , Baimbridge Fred 
Published: May 2008

Objective To evaluate a new material, poloxamer 407 reversethermal polymer, which may be of value in controlling bleeding during off-pump coronary anastomoses. Methods Poloxamer 407 reverse-thermal polymer is a clear, nontoxic compound that is a viscous liquid at room temperature but instantly changes to a firm, water-soluble gel when warmed to body temperature. Six pigs underwent off-pump coronary artery bypass with the left internal mammary artery to the left anterior descending coronary artery. Blood loss from the arteriotomy was measured over a 15-minute period before and after injection of 500 μL intracoronary polymer. After completion of the anastomosis, 10 mL of cold saline was poured along the left anterior descending artery to facilitate dissolution of the polymer. The heart was allowed to beat 2 additional hours with blood flowing through the left internal mammary to left anterior descending graft, after which a completion angiogram was obtained to evaluate graft patency and to look for gross angiographic evidence of coronary branch occlusion or intraluminal filling defects. The animals were then humanely euthanized, and myocardium from the area subtended by the left anterior descending was harvested for histologic evaluation. Results All animals successfully underwent the surgical procedure and survived until study termination without any complications. The amount of bleeding from coronary arteriotomy was significantly higher before intracoronary injection of the polymer (5.25 ± 1.65 mL/min versus 0.54 ± 0.53 mL/min, P = 0.0004). Angiography demonstrated that the graft was patent, and there was no evidence of intraluminal foreign bodies. Myocardial samples from the subtended bed showed no evidence of intraarterial polymer or myonecrosis. Conclusions Poloxamer 407 reverse-thermal polymer may be a valuable tool in performing coronary anastomoses off-pump. Completion angiograms showed total dissolution of the material with no residual intraarterial polymer visible on tissue samples.
New Instrument for Robotic-Enhanced Skeletonized Internal Thoracic Artery Harvesting: Triangular Hook
Authors: Ishikawa Norihiko , Sun You Su , Nifong L. Wiley , Watanabe Go , Chitwood W. Randolph 
Published: May 2008

Objective The introduction of robotic surgery has generated innovations in minimally invasive coronary surgery, including instrumentation. We have developed a small instrument, named by us the Triangular Hook, that expedites robotic skeletonization of the internal thoracic artery and makes the procedure safer. Methods Bilateral skeletonized internal thoracic artery harvesting was performed in four dogs (weight, 22 to 36 kg), using the da Vinci surgical system (Intuitive Surgical, Inc, Sunnyvale, CA). One internal thoracic artery was harvested with the Triangular Hook; the other was harvested without it. Harvesting time was measured for each form of harvesting, with the data being reported as mean ± SD. Results All eight internal thoracic arteries were harvested successfully; they were patent at the end of harvesting. Significantly less time was required for the Triangular Hook (41.5 ± 2.8 minutes) than for harvesting without it (47.5 ± 3.9 minutes; P = 0.02). Conclusions The Triangular Hook is practicable and safe in robotic skeletonization of the internal thoracic artery.
Video-Assisted Extended Transcervical Thymectomy
Authors: Komanapalli Christopher B. , Cohen James I. , Sukumar Mithran S. 
Published: May 2008

Objective The objective of this study was to demonstrate extended thymectomy via the transcervical route. Methods With the use of the Rultract retractor (Rultract, Cleveland, OH), videothoracoscopy and single-lung ventilation allowed complete thymectomy. Results This article demonstrates complete resection of all the thymus from the anterior and superior mediastinum. Conclusions In selected patients, the transcervical route can used to completely resect the thymus, avoiding the morbidity of sternotomy.
Beating Heart Aortic Valve Replacement using Real-Time MRI Guidance
Authors: Horvath Keith A. , Guttman Michael , Li Ming , Lederman Robert J. , Mazilu Dumitru , Kocaturk Ozgur , Karmarkar Parag V. , Hunt Timothy , Kozlov Shawn , McVeigh Elliot R. 
Published: May 2008

Objective The principal limitations of percutaneous techniques to replace the aortic valve are detailed visualization and durable prostheses. We report the feasibility of using real-time magnetic resonance imaging (MRI) to provide precise anatomic detail and visual feedback to implant a proven bioprosthesis. Methods Twelve domestic pigs were anesthetized, and, through a minimally invasive approach using real-time MRI guidance, underwent aortic valve replacement. This was accomplished on the beating heart by using a commercially available bioprosthesis. MRI was used to precisely identify the anatomic landmarks of the aortic annulus, coronary artery ostia, and the mitral valve leaflets. Additional intraoperative perfusion, flow velocity, and functional imaging were used to confirm adequacy of placement and function of the valve. Results Under real-time MRI, multiple oblique planes were prescribed to delineate the anatomy of the native aortic valve and left ventricular outflow track. Enhanced by the use of an active marker wire, this imaging allowed correct placement and orientation of the valve. Through a transapical approach, a series of bioprosthetic aortic valves (21 to 25 mm) were inserted. The time to implantation after the placement of the trocar to deployment of the valve was less than 90 seconds. The average procedure duration was less than 40 minutes Conclusions Real-time MRI provides excellent anatomic detail and intraoperative assessment that permits placement of durable valve prostheses on the beating heart without the limitations of percutaneous approaches.
Thoracoscopic Transmyocardial Laser Revascularization: Is Prior Coronary Artery Bypass Grafting a Contraindication?
Authors: Allen Gary S. , Budde Jason 
Published: May 2008

Objective Recently, thoracoscopic techniques have been used to perform transmyocardial laser revascularization (TMR) in patients who are not suitable candidates for coronary artery bypass graft (CABG) surgery or percutaneous coronary interventions. Whether or not prior CABG contraindicates a port access–only approach to TMR is unclear. This study compares patients with and without prior CABG who have undergone thoracoscopic TMR. Methods Between May 2003 and October 2005, 23 consecutive patients (6 without prior CABG, group A; and 17 with prior CABG, group B) underwent thoracoscopic TMR, using a holmium:yttriumaluminum-garnet (Ho:YAG) laser system. Either 3 or 4 port incisions (each ≤2 cm in length) were used, depending on the patient's anatomy. Procedural success was defined as the ability to create all intended channels without conversion to thoracotomy. Results Patient demographics were not significantly different between group A and group B (mean age, 65.8 ± 4.3 years versus 67.4 ± 2.4 years, Canadian Cardiovascular Society angina class 3.7 ± 0.2 versus 3.9 ± 0.1, and Parsonnet score 12.0 ± 3.2 versus 20.5 ± 2.4). Fourteen (82.4%) group B patients had a prior left internal mammary artery to left anterior descending artery graft, of which 12 (85.7%) were patent. One patient in group A had an airway injury at intubation that led to an extended hospital stay of 30 days. One patient in group A (16.7%) and one patient in group B (5.9%) required a blood transfusion (P = NS). Adhesion lysis time in group B ranged from 0 to 68 minutes (mean, 27 ± 5.6 minutes). Neither group had a conversion to thoracotomy or any deaths through a mean combined follow-up of 12 months. Conclusions A port access approach is safe and reproducible for patients who are candidates for sole therapy TMR. Prior CABG, including patent grafts, is not a contraindication to thoracoscopic TMR.
Quantitative Description of Mitral Valve Geometry Using Real-Time Three-Dimensional Echocardiography
Authors: Ryan Liam P. , Jackson Benjamin M. , Eperjesi Thomas J. , Plappert Theodore J. , John-Sutton Martin St. , Gorman Robert C. , Gorman Joseph H. 
Published: May 2008

Objectives Leaflet and annular geometry are important determinants of mitral valve (MV) stress. Repair techniques which optimize valvular geometry will reduce stress and potentially increase repair durability. The development of such procedures will require image processing methodologies that provide a quantitative description of three-dimensional valvular geometry. Using three-dimensional echocardiography in conjunction with novel geometric modeling and rendering techniques, we have developed a high-resolution, quantitative, three-dimensional methodology for imaging the human MV. Methods Five normal adults underwent MV imaging using real-time three-dimensional echocardiography. Using specially designed image analysis software, multiple valvular geometric parameters, including the magnitude and orientation of leaflet curvature, leaflet surface area, annular height, intercommissural width, septolateral annular diameter, and annular area were determined for each subject. Image rendering techniques that allow for the clear and concise presentation of this detailed information are also presented. Results Although three-dimensional annular and leaflet geometry were found to be highly conserved among normal human subjects, substantial regional variation in leaflet geometry was observed. Interestingly, leaflet geometric heterogeneity was most pronounced in the midposterior leaflet, the region most commonly involved in leaflet flail in subjects with myxomatous disease. Conclusions The image processing and graphical rendering techniques that we have developed can be used to provide a complete description of three-dimensional MV geometry in human subjects. Widespread application of these techniques to normal subjects and patients with MV disease will provide insight into the geometric basis of both valvular pathology and repair durability.
Transmyocardial Laser Revascularization Enhances Blood Flow within Bypass Grafts
Authors: Tran Richard , Brazio Philip S. , Kallam Seeta , Gu Junyan , Poston Robert S. 
Published: May 2008

Objective Early benefits from transmyocardial laser revascularization (TMR) may be related to acute sympathetic denervation. This study hypothesized that TMR as an adjunct to off-pump coronary artery bypass (OPCAB) would improve myocardial runoff in the TMR-treated regions and increase graft flow. Methods Graft blood flow was measured in 145 consecutive OPCAB patients. In patients with graft flow <40 mL/min (n = 25), the myocardial region served by the graft was treated with TMR. Blood flow was reassessed 10 minutes after TMR and compared with graft flow in the nontreated regions. Postoperative outcomes, transcardiac thrombin production, coagulation activation, myocardial, and inflammatory markers were assessed. A control group not treated with TMR (n = 14) was selected with similar graft flows and other baseline characteristics. Results Risk factors, comorbidities, and preoperative medications were similar in all groups. TMR led to a 48% increase in bypass graft flow in 12 patients, but no significant change in flow in the remainder (n = 13). The control group also showed no change in graft flow measured during the same time-points. Compared with those that did not respond to TMR, responders showed a greater drop in pH during warm ischemia caused by distal anastomoses during OPCAB and significantly higher transcardiac gradients of F1.2, IL-8, TNFα, and VCAM. Conclusions TMR acutely improves venous bypass graft flow in regions with more severe myocardial acidosis and inflammation during and after OPCAB. Acute sympathetic denervation after TMR may provide mechanistic insight into the early clinical benefits of TMR as an adjunct to OPCAB.
The relationships between the characteristics of the strategy process: evidence from Egypt
Authors: Elbanna Said , Younies Hassan 
Published: May 2008

PurposeStrategy process research has made considerable progress over the last 20 years and has produced a vast body of literature. This valuable contribution, however, has not adequately examined the relationships between the characteristics of the strategy process. This study aims to fill this gap by providing evidence on the relationships between the characteristics of the process of making strategic decisions (SDs) in a new setting.Design/methodology/approachThe study uses quantitative and qualitative methods.FindingsBased on quantitative and qualitative evidence from a sample of Egyptian companies, it was found that decision makers could be simultaneously rational, political and/or intuitive.Research limitations/implicationsThe study recommends further research to develop new constructs of the SD making process the way in which the multi‐dimensional nature of this organic process can be considered.Practical implicationsThe SD making process can be multi‐dimensionalOriginality/valueThe paper examines the relationships between the characteristics of the strategy process. It provides evidence on the relationships between the characteristics of the process of making strategic decisions (SDs) in a new setting.
Performance evaluation and analysis of lubricating oil using parameter profile approach
Authors: Sharma B.C. , Gandhi O.P. 
Published: May 2008

PurposeThe purpose of this paper is to evaluate and analyze lube oil performance. The plant experience shows that the oil, even after completion of a number of hours of recommended operation, has some residual life. It is desirable to maximize its use to conserve this scarce resource but avoid failures. At present, continuation or change of the oil is decided, based on the manufacturer's recommendation and experience in the plant. The suggested oil change period is conservative and results in non‐efficient usage of oil. This practice needs refinement to include all possible properties/attributes of oil and use of appropriate procedure to assess its realistic performance.Design/methodology/approachParameter profile approach (PPA) is applied to evaluate and analyze the lubricating oil performance parameters.FindingsPhysical and chemical properties related to degradation of the lube oil are considered as lubricating oil performance parameters. The value of these performance parameters from time to time, obtained by analyzing samples drawn from the system, are analyzed through PPA. In this approach, mean, median, performance parameter index and time performance index are defined and evaluated at different time intervals. The suggested procedure is illustrated by means of an example.Originality/valueThe suggested procedure will be helpful for the maintenance personnel in planned oil replacement, and in identifying the weak oil properties in respect of the identified lube oil performance parameters.
Tribological properties of Cyanex 301‐modified MoS2 nano‐sized hollow spheres in liquid paraffin
Authors: Zhou Xiaodong , Shi Huaqiang , Fu Xun , Wu Danmei , Hu Zhengshui 
Published: May 2008

PurposeThe purpose of this paper is to investigate the tribological properties of MoS2 nano‐sized hollow spheres in liquid paraffin (LP) and the corresponding action mechanism. Morever, its feasibity of industrial application as an oil additive in the industrial lubrication field is also explored.Design/methodology/approachThe tribological properties of MoS2 nano‐sized hollow spheres (NH‐MoS2) modified by Cyanex 301(di‐(2,4,4‐trimethylpentyl) dithiophosphinic acid) with size of 200 ∼ 300 nm in LP are studied and compared with those of the commercial colloidal MoS2 (CC‐MoS2) on a four‐ball tester and an Optimol SRV Oscillating friction and wear tester in a ball‐on disk configuration. The worn surfaces of the lower flat disc are examined with a scanning electron microscopy and an X‐ray photoelectron spectroscopy, respectively.FindingsResults show that NH‐MoS2 is a better extreme‐pressure additive and anti‐wear (AW) and friction‐reducing additive in LP than CC‐MoS2. Under the optimum concentration of 0.5 per cent for both NH‐MoS2 and CC‐MoS2 and the load of 400 N, the friction coefficient of NH‐MoS2 + LP and CC‐MoS2 + LP decreases about 43.8 and 6.3 per cent, and the wear volume loss decreases about 60.3 and 12.0 per cent compared with the pure LP. The boundary lubrication mechanism for NH‐MoS2 + LP can be deduced as the effective chemical adsorption protective film formed by the long chain alkyls R and active elements (S and P) in the modification layer and tribochemical reaction film containing the tribochemical products of the additive. Moreover, sliding and rolling frictions co‐exist in NH‐MoS2 + LP, doing contributions to the good tribological properties as well.Originality/valueIn this paper, the Cyanex 301‐modified MoS2 nano‐sized hollow spheres with diameter of 200 ∼ 300 nm are firstly added into LP to investigate its tribological properties. The excellent AW and friction‐reducing properties indicate that this MoS2 hollow spheres product is a good oil additive, and the fundamental data presented here will be useful for its further industrial application in the future.
Relevant marketing geography: a competency‐based perspective
Authors: Nicholson John D. , Lindgreen Adam , Kitchen Philip J. 
Published: May 2008

PurposeThe purpose of this paper is to apply the theory of relationship marketing to the previously unexplored context of organizations – from multiple sectors of society – that interact through no other apparent reason than geographic proximity. The paper assimilates literature from outside the discipline of marketing and synthesizes this with empirical findings in order to present a practical agenda for private sector firms in relation to their local region.Design/methodology/approachQualitative, convergent depth‐interviews and interdisciplinary literature synthesis.FindingsThe paper presents a model of relevant marketing geography, which positions a resource‐based view as a new direction for relationship marketing research. An additional model conceptualizes the competencies possessed by a private sector firm that allows the firm to access local stocks of social capital.Research limitations/implicationsThe paper offers the results of an exploratory, inductive investigation. Subsequent further research directions are significant and are outlined at the end of the paper.Practical implicationsInvolvement by private sector firms in their local region is often a random, spontaneous activity, or a reactive activity in response to prompts by public and third sector actors. The paper presents two models that move this agenda from emergent to planned strategic activity for private sector firms.Originality/valueThere is little if any previous discussion of research in the above outlined context within the marketing literature. This paper offers the potential for expansion of that literature.
The effects of team reflexivity and innovativeness on new product development performance
Authors: Tien‐Shang Lee Les 
Published: May 2008

PurposeTo determine the effects of project management skills, entrepreneurial proclivity, and existing knowledge on team reflexivity and performance of cross‐functional new product development (NPD) team. The moderating roles of team cohesiveness and knowledge practice are also explored.Design/methodology/approachThis study used online questionnaire surveys by inviting 500 R&D team members of NPD from three Science Parks in Taiwan. The survey questionnaires were sent to the representative of R&D team members.FindingsThe results indicate that members' project management skills, entrepreneurial proclivity, and existing knowledge have significant impact on team reflexivity and product innovativeness of the NPD project, which then influence NPD performance. Furthermore, NPD team exercising higher levels of team cohesiveness and higher knowledge practice tend to moderate the influence of team reflexivity and product innovativeness on NPD performance.Research limitations/implicationsThe use of longitudinal research is suggested to confirm the results of this study. Moreover, other research settings, either different industry or other countries, could increase the generalizability of the findings.Practical implicationsThe study has high implications for managers of NPD to recruit qualified team members who have adequate knowledge and strong entrepreneurial proclivity. Moreover, managers should be aware of the moderating role of team cohesiveness and knowledge practices.Originality/valueThe paper determines the antecedents and consequences of team reflexivity and innovativeness among NPD team members. The moderating role of team cohesiveness and knowledge practices are discussed.
Environmental munificence for entrepreneurs: entrepreneurial alertness and commitment
Authors: Tang Jintong 
Published: May 2008

PurposeExisting literature suggests that the need for a conducive environment is crucial in developing entrepreneurship. Previous research on this trend has focused on what constitutes a munificent environment and how environmental conditions stimulate an entrepreneur's intentionality to start a venture. However, little is known about how entrepreneurs “switch on” their alertness to business opportunities in a benign environment. The purpose of this paper is to examine the effects of environmental munificence on entrepreneurs' alertness, as moderated by self‐efficacy, and the effects of this alertness on entrepreneurs' commitment to their new ventures.Design/methodology/approachData were used from the Panel Study of Entrepreneurial Dynamics (PSED) to test the hypotheses. Exploratory Factor Analysis and Confirmatory Factor Analysis were conducted to ensure the dimensionality of entrepreneurial commitment scale. Hypotheses were tested using moderated hierarchical regression analysis.FindingsThe results of this study show a strong relationship between environmental munificence and alertness especially when the entrepreneurs have high levels of self‐efficacy in performing the roles and tasks of new venture creation. In turn, entrepreneurial alertness is related to continuance, behavioral and affective commitment of entrepreneurs.Originality/valueThe findings have important implications for the theory and practice of developing entrepreneurial firms.
A Balanced Scorecard framework for R&D
Authors: García‐Valderrama Teresa , Mulero‐Mendigorri Eva , Revuelta‐Bordoy Daniel 
Published: May 2008

PurposeThe purpose of this paper is to produce a general Balanced Scorecard (BSC) model that is designed and delimited for managing research and development (R&D) activities.Design/methodology/approachA methodology based on the validity of content of an instrument of measurement, within the analytical framework of the validation of scales or constructs was employed.FindingsThe BSC model for R&D developed in this study has been subject to testing with recognised experts in management and in R&D. It has enabled a proposal to be put forward in respect of those indicators that best define the factors related to organisational effectiveness in the achievement of the strategic objectives set by companies, and to inter‐relate them and group them under five broad perspectives of the BSC.Research limitations/implicationsThe BSC will be validated as a construct in future research.Practical implicationsThe result is the design of a scale of measurement that ranks the empirical indicators under the perspectives of the BSC; for the measurement of results, this instrument will provide unique values that group all the previous indicators in a single scale of measurement.Originality/valueNo studies dealing with the content validation of a BSC have been found in the literature on innovation.