Minimally-invasive, direct coronary artery bypass grafting

BACKGROUND: Minimally-invasive, direct vision coronary artery bypass grafting (MIDCAB) is a new surgical technique performed via limited thoracotomy in a beating heart without cardiopulmonary bypass. METHODS: From June 1996 to December 1996, MIDCAB was performed in 12 patients (all male, average age, 65.9 years). In 11 patients with left anterior descending coronary artery lesions, thoracotomy was performed via the left, fourth intercostal space and the pericardium was incised to identify the target site. About 8 cm of the left internal mammary artery was harvested. Bilateral anterolateral thoractomy was performed in one patient with left anterior descending and right coronary artery lesions. Anastomosis was performed under direct vision in the beating heart without cardiopulmonary bypass. RESULTS: MIDCAB was performed successfully without morbidity. The patients' average stay in the intensive care unit was 1.8 days. No patient had any early cardiac event requiring additional surgery or percutaneous transluminal coronary angioplasty. Postoperatively, all patients were asymptomatic and their recovery was uneventful. CONCLUSIONS: Our initial experience indicates that MIDCAB offers good results and is a treatment option for selected patients with left anterior descending and/or right coronary artery lesions.     

Variations in the composition dependence of the activity coefficient in terminal solid solutions of Ag−Zn,Ag−Cd,and Cu−Zn

The vapor pressure of zinc and cadmium over moderately dilute solutions of α Ag?Zn, α Ag?Cd, and α Cu?Zn was measured. An isothermal equilibrium technique was used, which was believed to give vapor pressures with relatively small error. Temperature coefficients of the vapor pressure were not measured. The purpose was to determine, with greater precision than has been obtained previously, the composition-dependence of the excess Gibbs free energy of the solute. It was found that the excess Gibbs free energy attains a minimum value in α Ag?Zn and α Cu?Zn, and there is a corresponding change ind In γCd/dx _Cd, although it does not go to zero, in α Ag?Cd. Such minima do not violate thermodynamic criteria for phase stability, but have not been reported previously.     

Adjoint acceleration of Monte Carlo simulations using TORT/MCNP coupling approach: a case study on the shielding improvement for the cyclotron room of the Buddhist Tzu Chi General Hospital

Full-scale Monte Carlo simulations of the cyclotron room of the Buddhist Tzu Chi General Hospital were carried out to improve the original inadequate maze design. Variance reduction techniques are indispensable in this study to facilitate the simulations for testing a variety of configurations of shielding modification. The TORT/MCNP manual coupling approach based on the Consistent Adjoint Driven Importance Sampling (CADIS) methodology has been used throughout this study. The CADIS utilises the source and transport biasing in a consistent manner. With this method, the computational efficiency was increased significantly by more than two orders of magnitude and the statistical convergence was also improved compared to the unbiased Monte Carlo run. This paper describes the shielding problem encountered, the procedure for coupling the TORT and MCNP codes to accelerate the calculations and the calculation results for the original and improved shielding designs. In order to verify the calculation results and seek additional accelerations, sensitivity studies on the space-dependent and energy-dependent parameters were also conducted.     

Novel cytotoxic diterpenes, excavatolides A-E, isolated from the Formosan gorgonian Briareum excavatum

The chemistry of Briareum excavatum, a Formosan gorgonian coral, was investigated. This study has led to the isolation of five novel marine natural products, excavatolides A-E (1-5), together with brianolide (6). The structures of the above compounds were established by spectral and chemical methods. The relative configuration of excavatolide B (2) was further confirmed by a single-crystal X-ray structure analysis. Cytotoxicity of these compounds toward various cancer cell lines also is described.     

Mutagenicity and identification of mutagenic compounds of fumes obtained from heating peanut oil

Since the fume of cooking oil has been reported to increase the risk of lung cancer, the objectives of this study were to evaluate the mutagenicity and to find the mutagens in the fumes of peanut oil heated to the smoke point. Peanut oil prepared from roasted peanut kernel showed a lower smoke point, less unsaturated fatty acids, more fume formation, and stronger mutagenicity than that from unroasted kernel. Further investigation of mutagenic compounds was performed by the Ames test and gas chromatography/mass spectrometry analysis. Among the 12 compounds identified from the neutral fraction of methanol extract, four compounds at a dose of 10 microg per plate were mutagenic to Salmonella Typhimurium TA98 and TA100 in the order of trans-trans-2,4-decadienal > trans-trans-2,4-nonadienal > trans-2-decenal > trans-2-undecenal. Results report the enal compounds formed as the mutagens in the fumes of peanut oil and indicate that inhaling cooking fumes might cause carcinogenic risk.     

Screening Procedures for Chloramphenicol Residue Determination in Serum,Milk, and Feedstuff Using Immunochromatographic Assay

The technology developed from this study is based on an immunochromatographic procedure that utilizes antigen-antibody properties using membrane carriers with immobilized immunoreactants and provides rapid and out-of-laboratory techniques. An evaluation of a colloidal gold-based immunochromatographic assay for chloramphenicol (CAP) residue detection in serum, milk and feed is described. Polyclonal antibodies against CAP were produced using CAP-IPA-MAA-ABA-bovine serum albumin (CAP-ed-BSA) conjugate as the immunogen, which exhibited no cross-reactivities with applied competitors in the studied concentration range. The test strip assay could be completed within 7 min, with a visual detection limit of 0.3 μg kg^?1 CAP in serum and milk and 0.5 μg kg^?1 CAP in feed. The established strip assay performed similarly as a commercial ELISA assay: the CAP test strip revealed a sensitivity of 90% (89–92%) and a specificity of 94% (91–98%), which showed appreciable accuracy and precision. The described strip is rapid, simple and cost-effective as well as sensitive and specific enough for reliable and accurate on-site screening.     

Turbo1500: Core-Based Design for Test and Diagnosis

Tool support is crucial in widespread adoption of a standard. This article describes a set of tools and associated flow for DFT insertion and test generation based on IEEE Std 1500.     

Rigid-plastic boundaries approach to the analysis of arbitrary profile dies in axisymmetric extrusion

A new theoretical model to analyze arbitrary profiles of extrusion dies is proposed in this paper. In this model, generalized rigid-plastic boundaries with optional variables are used to minimize the power by the upper-bound method. To satisfy the velocity boundary conditions at the entrance and exit, the streamline function is designed in the normal form of r(η, z), which satisfies the flow conditions and the rigid-plastic boundaries. Four sets of profile dies (cosine, elliptic, hyperbolic, and conic) are represented with different slopes at the entrance and exit in order to illustrate this method. Experiments were conducted in order to compare the results with those of the theoretical model. It was found that the predicted load and flow patterns were in agreement with the experimental observation and the results from the literature.     

Preform and forging process designs based on geometrical features using 2D and 3D FEM simulations

The requirements of compact and integrated industrial products make it more difficult to produce these complicated parts. The aim of this paper attempts to propose methods of finish forging die and preform designs to produce a product consisting of a solid spur gear and cylindrical cup features. One- and two-step forming processes were proposed and evaluated using computer-aided engineering simulations. For one-step extrusion or upsetting processes, diameters and heights of billet were calculated using the product volume and the corresponding cup or gear features, respectively. For two-step forming process, Tee-shaped preform designs were proposed based on the product volume and the feature volume ratio of cup to gear; corner and fillet arcs were adopted to modify the profile of Tee and control the material flow in the finisher die. The forming processes of preform and finisher were analyzed using the two- and three-dimensional finite-element method models to predict the detail characteristics of sectional material flow and the completely three-dimensional deformation results, respectively. Experimental tests were also carried out to validate the proposed simulation models and design methods. The forming loads, the stress and strain distributions of forged part, and the occurrences of defects were studied and a suitable preform and corresponding die designs were obtained. The proposed preform designs were verified via the numerical analyses for the feasibility study. Finally, a sound gear product had been made successfully using the proposed suitable design of preform.