Rorschach cognitive developmental indices of mentally retarded persons: a comparison with scores on Wechsler Intelligence Scale for children-revised

The complete mechanism by which pathogenic mtDNA mutations cause cellular pathophysiology and in some cases cell death is unclear. Oxidant stress is especially toxic to excitable nerve and muscle cells, cells that are often affected in mitochondrial disease. The sensitivity of cells bearing the LHON, MELAS, and MERRF mutations to oxidant stress was determined. All were significantly more sensitive to H2O2 exposure than their nonmutant cybrid controls, the order of sensitivity was MELAS > LHON > MERRF > controls. Depletion of Ca2+ from the medium protected all cell lines from oxidant stress, consistent with the hypothesis that death induced by oxidant stress is Ca(2+)-dependent. A potential downstream target of Ca2+ is the mitochondrial permeability transition, MPT, which is inhibited by cyclosporin A. Treatment of MELAS, LHON, and MERRF cells with cyclosporin A caused significant rescue from oxidant exposure, and in each case significantly greater rescue of mutant than control cells. The pronounced oxidant-sensitivity of mutant cells, and their protection by Ca2+ depletion and CsA, has potential implications for both the pathophysiological mechanism and therapy of these mitochondrial genetic diseases.     

An optimization framework for “build-or-buy” decisions in software architecture

Building a software architecture that meets functional requirements is a quite consolidated activity, whereas keeping high quality attributes is still an open challenge. In this paper we introduce an optimization framework that supports the decision whether to buy software components or to build them in-house upon designing a software architecture. We devise a non-linear cost/quality optimization model based on decision variables indicating the set of architectural components to buy and to build in order to minimize the software cost while keeping satisfactory values of quality attributes. From this point of view, our tool can be ideally embedded into a Cost Benefit Analysis Method to provide decision support to software architects. The novelty of our approach consists in building costs and quality attributes on a common set of decision variables related to software development. We start from a special case of the framework where the quality constraints are related to the delivery time and the product reliability, and the model solution also devises the amount of unit testing to be performed on built components. We generalize the framework formulation to represent a broader class of architectural cost-minimization problems under quality constraints, and discuss advantages and limitations of such approach.     

Effect of the metallic substrate and zinc layer on the atmospheric corrosion resistance of phosphatized and painted electrogalvanized steels

In this work, the influence of the metallic substrate and zinc layer on the atmospheric corrosion resistance of phosphatized and painted electrogalvanized steels was evaluated. For this purpose two types of electrogalvanized steels were used, one with drawing quality carbon steel as metallic substrate, and the other one with a substrate of Ni–Cu–Cr added carbon steel. The corrosion resistance was determined by accelerated and non‐accelerated corrosion tests, using cyclic test chambers and field tests in industrial and marine atmosphere. The mean corrosion advance and the maximum corrosion penetration of samples were measured using image analysis techniques. The study showed that the substrate and zinc layer mass play a decisive role on the atmospheric corrosion resistance of the phosphatized and painted electrogalvanized steels. It was also verified that it is possible to use smaller zinc layer masses without compromising the corrosion resistance of the material, provided that the metallic substrate has characteristics of atmospheric corrosion resistance, thus contributing to the improvement of the zinc coated steels.     

Controlled filling and external cleaning of multi-wall carbon nanotubes using a wet chemical method

A controlled, material-independent and adaptable cold wet chemical procedure is described. It allows organic and inorganic compounds to be confined inside multi-wall carbon nanotubes. The procedure mainly consists of a lyophilization process to fill multi-wall carbon nanotubes (MWCNTs), and a washing method to clean their outer surface without removing the encapsulated material. The technique was tested by synthesizing CdS crystals inside the nanotubes. Morphological and structural studies of the CdS crystals demonstrated a complete control of the synthesis process, and the possibility of maximizing the crystal size and the filling efficiency that approached 70% of open-ended nanotubes.     

实现长时间PWM软启动的简单电路

UC384X系列电流模式PWM(脉冲宽度调制)电源控制器有多种获取来源,它有很好的性能,并派生出了大量相似的IC.所有UC384X系列的成员及其变型都有一个共同的特性:即有一个提供限流输出的内部电压误差放大器.     

Palladium‐Catalyzed [2+1] Cycloadditions Affording Vinylidenecyclopropanes as Precursors of 7‐Membered Carbocycles

Palladium(II) acetate in association with secondary phosphine oxides provides an efficient catalytic system for [2+1] cycloadditions starting from oxanorbornene derivatives and tertiary propargyl esters giving rise to vinylidenecyclopropanes. This reaction is specific to bidentate phosphinito–phosphinous acid ligands generated from secondary phosphine oxides. The [2+1] cycloaddition was found broad in scope with a high tolerance to various functional groups. Moreover, vinylidenecyclopropanes were straightforwardly converted into oxabicyclo[3.2.1]oct‐2‐ene derivatives through a palladium‐catalyzed ring‐expansion. Finally, the oxa bridge cleavage of oxatricyclic compounds yields functionalized 7‐membered carbocycles.

     

Runge Kutta Type Methods for Isodynamical Matrix Flows: Applications to Balanced Realizations

Recently several numerical methods have been proposed for solving isospectral problems which are matrix differential systems whose solutions preserve the spectrum during the evolution. In this paper we consider matrix differential systems called isodynamical flows in which only a component of the matrix solution preserves the eigenvalues during the evolution and we propose procedures for their numerical solution. Applications of such numerical procedures may be found in systems theory, in particular in balancing realization problems. Several numerical tests will be reported. Received April 27, 2001; revised October 25, 2001 Published online February 18, 2002     

The renal medulla and mechanisms of hypertension in the spontaneously hypertensive rat

A significant number of offspring from brother-sister matings of NIH-Okamoto-Aoki spontaneously hypertensive rats (SHRs) were found to be normotensive at 20 weeks of age. Over 20% of the animals that were hypertensive at this age had mild-to-moderate unilateral hydronephrosis at the time of sacrifice. In over 90% of the rats that did not develop hypertension spontaneously, ligation of one ureter raised blood pressure above 150 mm Hg within 2 weeks. In those rats made hypertensive by obstructing one ureter and in those that developed hypertension with accompanying naturally occurring hydronephrosis, subcutaneous implants of fragmented renal medulla from unrelated normal rats decreased blood pressure to normotensive levels. In contrast, medullary implants had no significant effect in rats developing hypertension spontaneously without hydronephrosis. Renal inner medullary plasma flow was low in the obstructed kidneys of hydronephrotic hypertensive SHRs but was elevated in the kidneys of nonhydronephrotic hypertensive SHRs. The hypertension in hydronephrotic SHRs appears to be related to an impairment of the antihypertensive function of the renal medulla. Such an impairment of medullary antihypertensive function does not appear to play a significant role in the hypertension in SHRs without hydronephrosis.     

Effects of Different Types of Chronic Training on Bioenergetic Profile and Reactive Oxygen Species Production in LHCN-M2 Human Myoblast Cells

Human skeletal muscle contains three different types of fibers, each with a different metabolism. Exercise differently contributes to differentiation and metabolism in human myoblast cells. The aims of the present study were to investigate the effects of different types of chronic training on the human LHCN-M2 myoblast cell bioenergetic profile during differentiation in real time and on the ROS overproduction consequent to H₂O₂ injury. We demonstrated that exercise differently affects the myoblast bioenergetics: aerobic exercise induced the most efficient glycolytic and oxidative capacity and proton leak reduction compared to untrained or anaerobic trained sera-treated cells. Similarly, ROS overproduction after H₂O₂ stress was lower in cells treated with differently trained sera compared to untrained sera, indicating a cytoprotective effect of training on the reduction of oxidative stress, and thus the promotion of longevity. In conclusion, for the first time, this study has provided knowledge regarding the modifications induced by different types of chronic training on human myoblast cell bioenergetics during the differentiation process in real time, and on ROS overproduction due to stress, with positive implications in terms of longevity.