Permeation decomposition of urea through asymmetrically urease-immobilized ethylene-vinyl alcohol copolymer membranes

Urease-immobilized ethylene-vinyl alcohol copolymer (EVA) membrane was prepared by the covalent bonding of urease on EVA membrane activated with cyanuric chloride. The urease-immobilized EVA membrane had optimum pH at about 7.0 similar to native urease. The Michaelis constant (K_m) and the maximum velocity (V_m) of the urease-immobilized EVA membrane were smaller than those of native urease. When the EVA membrane, prepared on a polyethylene (PE) plate by the phase inversion method, was used as a support, urease was asymmetrically distributed in the direction of cross section of the urease-immobilized EVA membrane. The permeation decomposition of urea through the asymmetrically urease-immobilized EVA membrane depended on the asymmetric distribution of urease in the membrane. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1579–1588, 1997     

Fiber structure formation in ultra-high-speed melt spinning of poly(ethylene 2,6-naphthalene dicarboxylate)

The high-speed melt spinning of poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) was performed up to the take-up velocity of the ultra-high-speed region, 9 km/min. From the investigations of the structure and physical properties of the as-spun fibers, the high-speed spinning of PEN was divided into three regions in terms of the mechanism of fiber structure formation. The first region is the take-up velocity of up to 2.5 km/min and the birefringence of up to 0.08 where only a slight increase in molecular orientation was attained. At the take-up velocity of 2.5–4.5 km/min and the birefringence of 0.08–0.25, although some experimental evidences indicated that the orientation-induced crystallization did not occur, there was an increase in the fiber density which suggested the formation of some ordered structure. At the take-up velocity > 4.5 km/min and birefringence > 0.25, the orientation-induced crystallization occurred. The fibers obtained in this region were characterized by the formation of the crystalline structure dominated by the β form. The presence of the necklike deformation in the spinning line was also confirmed. The solidification temperature of the spinning line analyzed from the diameter profile suggested that the formation of β modification crystals occurred at relatively low crystallization temperatures in comparison with that in an isotropic state. Therefore it was indicated that the presence of elongational stress in the spinning line promoted the formation of the β modification crystals. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1415–1427, 1997     

Effect of [60] Fullerene on the Chondrogenesis in Mouse Embryonic Limb Bud Cell Culture System

Abstract

[60] Fullerene solubilized with polyvinylpyrrolidone (PVP) promoted the mouse embryonic limb bud cell differentiation specifically. The cell lysis caused by C60 was diminished by the addition of superoxide dismutase and catalase.     

Thrombospondin-1 in Urological Cancer: Pathological Role,Clinical Significance,and Therapeutic Prospects

Angiogenesis is an important process for tumor growth and progression of various solid tumors including urological cancers. Thrombospondins (TSPs), especially TSP-1, are representative “anti”-angiogenic molecules and many studies have clarified their pathological role and clinical significance in vivo and in vitro. In fact, TSP-1 expression is associated with clinicopathological features and prognosis in many types of cancers. However, TSP-1 is a multi-functional protein and its biological activities vary according to the specific tumor environments. Consequently, there is no general agreement on its cancer-related function in urological cancers, and detailed information regarding regulative mechanisms is essential for a better understanding of its therapeutic effects and prognostic values. Various “suppressor genes” and “oncogenes” are known to be regulators and TSP-1-related factors under physiological and pathological conditions. In addition, various types of fragments derived from TSP-1 exist in a given tissue microenvironment and TSP-1 derived-peptides have specific activities. However, a detailed pathological function in human cancer tissues is not still understood. This review will focus on the pathological roles and clinical significance of TSP-1 in urological cancers, including prostate cancer, renal cell carcinoma, and urothelial cancer. In addition, special attention is paid to TSP-1-derived peptide and TSP-1-based therapy for malignancies.     

Planning in human children (Homo sapiens) assessed by maze problems on the touch screen.

The authors examined how human children perform on maze tasks on the touch screen and whether the children plan the solution of the mazes. In Experiment 1, the authors exposed children around 3 years of age to a maze having an L-shaped line as a barrier that can be solved by moving an illustration of a dog (the target) to that of a bone (the goal) with their fingers. The participants successfully solved the maze by taking efficient routes more frequently than chance, although the authors found no evidence that a preview of the maze before starting to solve the task facilitated their performance. In Experiment 2, using a plus-shaped maze, the authors found that 3- and 4-year-old children plan and adjust their moves while solving the maze, with 4-year-olds showing more advanced and higher-level planning than 3-year-olds. Similarity of these results to what the authors previously found in pigeons tested in the same tasks may suggest an analogy for planning capacity in the behavioral level across taxa and developmental stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Real-time simulation of lightweight rigid bodies

Unlike common rigid bodies, lightweight rigid bodies have special and spectacular motions that are known as free fall, such as fluttering (oscillation from side to side) and tumbling (rotation and sideways drifting). However, computer graphics applications cannot simulate the dynamics of lightweight rigid bodies in various environments realistically and efficiently. In this study, we first analyze the physical characteristics of free-fall motions in quiescent flow and propose a new procedural motion-synthesis method for modeling free-fall motions in interactive environments. Six primitive motions of lightweight rigid bodies are defined in a phase diagram and analyzed separately using a trajectory-search tree and precomputed trajectory database. The global paths of free-fall motions are synthesized on the basis of these primitive motions by using a free-fall motion graph whose edges are connected in the Markov-chain model. Then, our approach integrates external forces (e.g., a wind field) by using an improved noise-based algorithm under different force magnitudes and object release heights. This approach exhibits not only realistic simulation results in various environments but also fast computation to meet real-time requirements.     

Coronary artery bypass grafting in cases with poor left ventricular function

From January 1987 through June 1992, 18 patients with poor left ventricular function (left ventricular ejection fraction [LVEF] less than 0.3) underwent elective isolated primary coronary artery bypass surgery. The mean age was 56.4 years (range, 46 to 72 years), and 15 were males and 3 were females. Mean pre-operative LVEF measured by ventriculography was 0.26 +/- 0.03 (range, 0.19 to 0.30). Sixteen patients (88.9%) had a prior myocardial infarction and 9 (50%) had a history of congestive heart failure. Complete revascularization was the goal for all patients, and the mean number of bypass grafts was 3.0 +/- 0.8 per patient. The left anterior descending coronary artery (LAD) was revascularized in all patients. There were no operative deaths. Post-operative LVEF improved significantly from 0.26 +/- 0.03 to 0.42 +/- 0.11 (p = 0.0002), and the regional left ventricular wall motion improved in the diaphragmatic and posterobasal regions (p < 0.01). The patency of the grafts was 93.9% in all, and 100% for LAD. The mean follow-up period was 77 months, and the overall actuarial survival rate was 88.9% at 10 years. During follow-up periods, two patients died of congestive heart failure (CHF), and two required three rehospitalizations because of CHF. The overall cardiac event free rate was 75.8% at 10 years. In patients with poor left ventricular function, surgical revascularization can be performed safely, but congestive heart failure sometimes occurs during follow-up periods and may be the cause of death. Therefore alternate forms of therapy such as cardiac transplantation and/or TMLR should be considered in selected patients.