Output tracking control of uncertain nonlinear second-order systems

The solution of a tracking problem for a secondorder nonlinear system with uncertain dynamics and incomplete state measurement is obtained by means of a procedure directly inspired by the solution of the classical minimum-time optimal control problem. Two different types of uncertainty are considered in the paper: in the first case a constant bound on the uncertain dynamics is assumed to be known; in the second case, the bound is a function of both the measurable and the unmeasurable state variable of the system. In both cases, the possibility of applying the proposed control algorithms is proved to be determined by a proper choice of the control signal features. The resulting system is characterized by a suitable feedback switching logic and the convergence of the system trajectory to the desired one (or to a δ-vicinity of this latter) is proved also in the uncertain case.     

Behavior of the polymorphonuclear leukocyte membrane fluidity and cystolic Ca2+ content in vascular atherosclerotic disease with and without non-insulin-dependent diabetes mellitus

In 71 subjects with vascular atherosclerotic disease (VAD), in 32 VAD subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in 31 normal controls, we evaluated polymorphonuclear leukocyte (PMN) membrane fluidity and PMN cytosolic Ca2+ content. The PMN membrane fluidity was obtained by marking intact and unstimulated PMN cells with fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) and the PMN cytosolic Ca2+ content was obtained by marking intact and unstimulated PMN cells with the fluorescent probe Fura 2-AM. From the obtained results, it is evident that PMN membrane fluidity does not differentiate normals from VAD subjects and VAD subjects with NIDDM, and normals from subjects with monovascular disease (MVAD) and polyvascular disease (PVAD) with and without NIDDM. The PMN cytosolic Ca2+ content is significantly increased in VAD subjects and VAD subjects with NIDDM, and also in MVAD and PVAD subjects with and without NIDDM. A positive correlation is present between PMN membrane fluidity and PMN cytosolic Ca2+ content in normals and VAD subjects, but not in VAD subjects with NIDDM. In conclusion, in VAD subjects with and without NIDDM, an increase of the PMN cytosolic Ca2+ content is present; this increase might be related to the PMN spontaneous activation.     

Sex differences in insulin levels in older adults and the effect of body size, estrogen replacement therapy, and glucose tolerance status. The Rancho Bernardo Study, 1984-1987

OBJECTIVE--To determine if insulin levels vary with sex, independent of estrogen replacement therapy (ERT), differences in body mass index (BMI), waist-to-hip ratio (WHR), and glycemia. RESEARCH DESIGN AND METHODS--In a population-based study of older adults, insulin levels were measured before and after a standardized oral glucose tolerance test in 673 men and 849 women, all free of known diabetes. RESULTS--Age-adjusted fasting insulin levels were highest in men, intermediate in women not taking estrogen, and lowest in estrogen-treated women (P < 0.01). Differences between men and women not taking estrogen disappeared after adjusting for age and BMI, but not glycemia; estrogen-treated women had significantly lower fasting insulin levels than did men (P < 0.01) and women not taking estrogen (P < 0.01). The association of estrogen use with lower fasting insulin levels persisted after adjusting for age and WHR (P < 0.001) and was stronger among women with abnormal glucose tolerance. Age-adjusted postchallenge insulin levels were higher in women than in men (P < 0.01). The sex difference persisted after adjusting for age and BMI or glycemia. Postchallenge insulin levels did not vary by ERT. CONCLUSIONS--Men have higher fasting insulin levels than do women, whether or not the women are using ERT. Differences between men and untreated women are explained by differences in BMI, but estrogen users have lower fasting insulin levels independent of BMI. Postchallenge insulin levels are higher in women than men and are independent of ERT, BMI, and glycemia. Clinical trials in women are needed to determine whether ERT can improve insulin and glucose metabolism.     

An apparatus for cyclic tests on cylindrical concrete specimens

An apparatus specifically designed for static and cyclic testing of concrete and rock cylindrical samples is described. A particular characteristic of this equipment is the possibility of cyclic variation of the confining pressure, in addition to variation of the vertical load. The technical features of the apparatus are illustrated, as well as those of the instruments used for measuring and recording the variation of loads and displacements during the tests, up to the failure of the specimens. Comments are also presented on the devices controlling the variation of load with time and on the characteristics of the load histories adopted in an experimental research aimed at investigating the behaviour of concrete under repeated triaxial loads.     

Humanization of an anti-vascular endothelial growth factor monoclonal antibody for the therapy of solid tumors and other disorders

Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis associated with tumors and other pathological conditions, including proliferative diabetic retinopathy and age-related macular degeneration. The murine anti-human VEGF monoclonal antibody (muMAb VEGF) A.4.6.1 has been shown to potently suppress angiogenesis and growth in a variety of human tumor cells lines transplanted in nude mice and also to inhibit neovascularization in a primate model of ischemic retinal disease. In this report, we describe the humanization of muMAb VEGF A.4.6.1. by site-directed mutagenesis of a human framework. Not only the residues involved in the six complementarity-determining regions but also several framework residues were changed from human to murine. Humanized anti-VEGF F(ab) and IgG1 variants bind VEGF with affinity very similar to that of the original murine antibody. Furthermore, recombinant humanized MAb VEGF inhibits VEGF-induced proliferation of endothelial cells in vitro and tumor growth in vivo with potency and efficacy very similar to those of muMAb VEGF A.4.6.1. Therefore, recombinant humanized MAb VEGF is suitable to test the hypothesis that inhibition of VEGF-induced angiogenesis is a valid strategy for the treatment of solid tumors and other disorders in humans.     

Laparoscopic incisional hernia repair after transverse rectus abdominis myocutaneous flap reconstruction

Abdominal wall herniation is a relatively rare but well recognized complication that is known to occur following TRAM flap mobilization. Herein is presented a novel means to approach such a hernia, using the minimally invasive surgical approach to repair the defect with a piece of prosthetic material.     

Automation of human sperm cell analysis by flow cytometry

Semen sample analysis is routinely performed by microscopical evaluation and manual techniques by laboratory operators; the analysis is affected by a wide imprecision related to variability among observers, influencing its clinical validity. Our aim was to automate sperm analysis with the use of flow cytometry for evaluation of cell counts and typing and with the use of a new membrane-permeant nucleic acid stain for evaluation of sperm viability. Statistical analysis of the comparison between manual and automated methods for sperm counts was performed by the Bland and Altman method; the mean difference was 0.243 x 10(6) sperms/ mL. The precision of the flow cytometric analysis was evaluated with whole sperm; the between-run CV was 7.5% and the within-run CV was 2.5%. Data observed suggest that flow cytometric sperm analysis, with high precision and accuracy and low costs, can be proposed for routine use in clinical laboratories.     

Extracting knowledge patterns with a social network analysis approach: an alternative methodology for assessing the impact of power inventors

This paper proposes a new, alternative analysis of patent data in order to extract knowledge patterns from inventors’ collaboration networks. Indeed, moving from a basic network analysis, we provide new developments to map and study co-inventorship. The goal of this research is to provide an overall understanding of the dynamics concerning knowledge flows in inventive activities. We show how the network of inventors is, on average, increasing in size: more and more inventors are contributing to technology innovations and they are more connected to each other. We also show to what extent inventors from different countries tend to cooperate with their local peers or internationally. Furthermore, an analysis of the clustering of inventors is carried out to show differences across countries in the structure of inventors’ communities, with a particular focus on the dynamics of collaboration for power inventors (i.e. star inventors).