Balloon catheter systems for PTCA: the importance of the catheter length

This complex study was designed to measure the transport and excretion characteristics of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dog's livers following bolus and infusion. Simultaneous T1 magnetic resonance imaging was performed to measure maximum signal enhancement. Anaesthetized dogs had cannulation of the common bile duct and urinary bladder for collections and cannulation of the femoral artery and vein for monitoring, blood sampling and infusion. Gd-EOB-DTPA was administered by bolus (range 12.5-200 mumol/kg) and infusion (range 0.4-6.4 mumol/min per kg). An hepatic transport maximum 0.09-0.15 mumol/min/kg was achieved with a blood concentration of 0.03-0.06 mumol/mL. Marked hepatic affinity for Gd-EOB-DTPA was demonstrated with measurements of liver concentration. Maximum T1 signal enhancement was achieved with blood Gd-EOB-DTPA concentration of 0.02-0.03 mumol/mL and a liver concentration of 1-2 mumol/g. The transport maximum for Gd-EOB-DTPA in the dog was similar to that for ipodate and iodipamide and effective imaging was achieved with sub-maximal doses. The maximum signal enhancement at blood concentrations less than required for maximum transport suggest a wide latitude for effective clinical imaging.     

Transient thermal behavior in a new RTP chamber

The transient thermal behavior of 200 and 300 mm wafers in a new rapid thermal processing (RTP) chamber is investigated. The AST3000 is a new RTP tool to meet the process requirements for both wafer sizes in 0.18 μm technologies and beyond. In this paper, experimental results obtained on both 200 and 300 mm wafers for varying processing conditions are shown: spike anneal experiments with fast ramp rates up to 200°C/s were performed. For standard anneal recipes, the steady state time is varied in a broad range and also the inherent temperature uniformity is investigated.     

History of the Kolff Laboratory turbine driven electrohydraulic artificial heart

The concept of an electrically powered total artificial heart has been pursued by Dr. Kolff and his associates since the 1960s. Since the 1980s these efforts have been concentrated upon the development of the electrohydraulic total artificial heart, a turbine pump powered by a brushless DC motor. Dr. Kolff realized the benefits of pulsatile flow and device response to Starling's Law, and these concepts have formed the basis of subsequent design decisions. Design iterations have both solved existing problems and exposed new challenges. The current device design is greatly improved over early attempts due to the incorporation of technologies that have recently become available as the result of progress in the fields of materials and electronics and due to the lessons learned over many years of research under the guidance of Dr. Kolff. This article describes, from its inception, the last major research project of Dr. Kolff prior to his retirement. The discussion centers around development, problems and their solutions, and the reasoning for given solutions.     

A Survey of Flattening‐Based Medical Visualization Techniques

In many areas of medicine, visualization research can help with task simplification, abstraction or complexity reduction. A common visualization approach is to facilitate parameterization techniques which flatten a usually 3D object into a 2D plane. Within this state of the art report (STAR), we review such techniques used in medical visualization and investigate how they can be classified with respect to the handled data and the underlying tasks. Many of these techniques are inspired by mesh parameterization algorithms which help to project a triangulation in ?³ to a simpler domain in ?². It is often claimed that this makes complex structures easier to understand and compare by humans and machines. Within this STAR we review such flattening techniques which have been developed for the analysis of the following medical entities: the circulation system, the colon, the brain, tumors, and bones. For each of these five application scenarios, we have analyzed the tasks and requirements, and classified the reviewed techniques with respect to a developed coding system. Furthermore, we present guidelines for the future development of flattening techniques in these areas.     

The dissolution of silver cathodically polarized in acid chloride media

The dissolution of silver cathodically polarized in a 1M HC1 solution is investigated. It occurs only in the presence of oxygen, is independent of the cathodic potential in a range from 0.00 to −0.45 V, and is determined by the convective experimental conditions and the acidity of the solution. It may be assumed that silver can be oxidized at cathodic potentials because of an increase in the concentration of hydroxide ions adsorbed by the electrode, during the reduction of the dissolved oxygen. Original Russian Text ? L.E. Volkova, I.K. Marshakov, N.M. Tutukina, I.V. Kreiser, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 2, pp. 154–157.     

Miniature compression force tester [2006 Myron Zucker Prize winner]

This report describes the development of a miniature tensile force-testing device used to test automotive pinch strips. The primary purpose of this device is to aid in the characterization of pinch strips by determining the compressive force required to activate a pinch strip over an ambient temperature and the size of an object applying force to the strip. The user software was developed to allow the test operator to run tests and collect and display test data     

Therapeutic Strategies to Reduce the Toxicity of Misfolded Protein Oligomers

The aberrant aggregation of proteins is implicated in the onset and pathogenesis of a wide range of neurodegenerative disorders, including Alzheimer’s and Parkinson’s diseases. Mounting evidence indicates that misfolded protein oligomers produced as intermediates in the aggregation process are potent neurotoxic agents in these diseases. Because of the transient and heterogeneous nature of these elusive aggregates, however, it has proven challenging to develop therapeutics that can effectively target them. Here, we review approaches aimed at reducing oligomer toxicity, including (1) modulating the oligomer populations (e.g., by altering the kinetics of aggregation by inhibiting, enhancing, or redirecting the process), (2) modulating the oligomer properties (e.g., through the size–hydrophobicity–toxicity relationship), (3) modulating the oligomer interactions (e.g., by protecting cell membranes by displacing oligomers), and (4) reducing oligomer toxicity by potentiating the protein homeostasis system. We analyze examples of these complementary approaches, which may lead to the development of compounds capable of preventing or treating neurodegenerative disorders associated with protein aggregation.