Breast augmentation: Psychological and plastic surgery considerations.

Addresses motivations for and reactions to augmentation mammoplasty and reports on a study of 32 adult Caucasian women who were followed for a minimum of 1 yr after surgery. The positive impact of offering the possibility for postoperative volume adjustment is noted. Contraindications for this surgery and possibilities for interdisciplinary collaboration are stressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental study of the ternary system Cd---Te---Zn

The ternary system Cd---Zn---Te has been studied by differential thermal analysis, differential scanning calorimetry and X-ray powder diffraction. A solid solution is observed between CdTe and ZnTe. At low temperature this quasi-binary section exhibits a miscibility gap. The liquid-liquid miscibility gap induced by the binary monotectic reaction extends within the ternary system and its boundary has been determined. The only ternary reaction existing in this system is a eutectic reaction at 265 °C and the corresponding composition is located in the very close neighbourhood of the binary eutectic Cd---Zn.     

Three-dimensional modelling of selective dissolution and passivation of iron-chromium alloys

A three-dimensional model has been developed for modelling the selective dissolution and passivation of alloys. The model has been used to simulate the passivation of iron-chromium alloys. The real structure of the alloy is taken into account (bcc in the present case), as well as the structure of the initial surface. The passivation is modelled in considering the formation of “oxide” nuclei, resulting from the presence of local chromium-rich clusters. During the dynamic evolution of the model, based on the Monte Carlo method, surface diffusion and dissolution of atoms occur according to probabilities dependent on the nature of the atom (Cr or Fe) and on its chemical environment. The conditions of simulation can be changed through a set of parameters defining the rules for surface diffusion, selective dissolution and number of Cr atoms in the Cr clusters required to initiate locally the passivation. The effects of these parameters on the simulation have been tested for an alloy containing 22 at.% Cr and compared with experimental data. The results show that the diffusion of Fe has little influence on the course of passivation while the diffusion of Cr has a marked effect. When the number of surface chromium atoms required to form a nucleus of passive film increases, the passivation becomes less rapid, with a marked effect on the composition of the passivated layer. The extent of the chromium enrichment in the passivated surface obtained in the model for the initial stages of passivation is not as high as the one measured experimentally in the stationary state of passivity.Other simulations have then been performed with various chromium contents in the alloy. The results show the existence of a transition, which is not sharp but progressive, between alloys that cannot be passivated to alloys that are passivated.     

The contact problem in Lagrangian systems subject to bilateral and unilateral constraints,with or without sliding Coulomb’s friction: a tutorial

This work deals with the existence and uniqueness of the acceleration and contact forces for Lagrangian systems subject to bilateral and/or unilateral constraints with or without sliding Coulomb’s friction. Sliding friction is known to yield singularities in the system, such as Painlevé’s paradox. Our work aims at providing sufficient conditions on the parameters of the system so that singularities are avoided (i.e., the contact problem is at least solvable). To this end, the frictional problem is treated as a perturbation of the frictionless case. We provide explicit criteria, in the form of calculable upper bounds on the friction coefficients, under which the frictional contact problem is guaranteed to remain well-posed. Complementarity problems, variational inequalities, quadratic programs and inclusions in normal cones are central tools.     

Cements in the 21st century: Challenges,perspectives, and opportunities

Since its widespread use in concrete began over 100 years ago, the chemical composition and physical properties of portland cement have changed only incrementally in response to various and competing pressures of constructability and cost. Instead, the construction demands have been met largely through the development and introduction of chemical admixtures that are added to the binder during mixing. These same demands persist into the 21^st Century and are just as important now as before, yet newer driving forces are simultaneously pushing the industry both toward more automated construction and toward more sustainable concrete materials that generate lower CO₂ and have longer service life. These new cement binder formulations and new construction technologies are expected to go well outside the bounds of traditional portland cement compositions and batching and placing practices. This study examines the origins of these new market demands and the influence they are having on the construction industry. Seven scientific or technological pathways are identified that will be critical for enabling the kinds of transformational changes in cement and concrete construction that the industry needs: (i) additive manufacturing, (ii) designer admixtures, (iii) curated materials data repositories, (iv) computationally designed composites, (v) big data and smart materials, (vi) alternative binder compositions, and (vii) next‐generation instrumentation.     

Lipid Emulsions Containing Medium Chain Triacylglycerols Blunt Bradykinin-Induced Endothelium-Dependent Relaxation in Porcine Coronary Artery Rings

Lipid emulsions for parenteral nutrition are used to provide calories and essential fatty acids for patients. They have been associated with hypertriglyceridemia, hypercholesterolemia, and metabolic stress, which may promote the development of endothelial dysfunction in patients. The aim of the present study was to determine whether five different industrial lipid emulsions may affect the endothelial function of coronary arteries. Porcine coronary artery rings were incubated with lipid emulsions 0.5, 1, or 2% (v/v) for 30 min before the determination of vascular reactivity in organ chambers and the level of oxidative stress using electron paramagnetic resonance. Incubation of coronary artery rings with either Lipidem^®, Medialipid^® containing long- and medium-chain triacylglycerols (LCT/MCT), or SMOFlipid^® containing LCT, MCT, omega-9, and -3, significantly reduced the bradykinin-induced endothelium-dependent relaxation, affecting both the nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) components, whereas, Intralipid^® containing LCT (soybean oil) and ClinOleic^® containing LCT (soybean and olive oil) did not have such an effect. The endothelial dysfunction induced by Lipidem^® was significantly improved by indomethacin, a cyclooxygenase (COX) inhibitor, inhibitors of oxidative stress (N-acetylcysteine, superoxide dismutase, catalase) and transition metal chelating agents (neocuproine, tetrathiomolybdate, deferoxamine and l-histidine). Lipidem^® significantly increased the arterial level of oxidative stress. The present findings indicate that lipid emulsions containing LCT/MCT induce endothelial dysfunction in coronary artery rings by blunting both NO- and EDH-mediated relaxations. The Lipidem^®-induced endothelial dysfunction is associated with increased vascular oxidative stress and the formation of COX-derived vasoconstrictor prostanoids.     

Structural Characterization and Protein Adsorption Property of Hydroxyapatite Particles Modified With Zinc Ions

Zinc-containing hydroxyapatite particles (Zn/HAp) were prepared by an ion exchange reaction process involving hydroxyapatite (HAp) particles with aqueous solutions containing various amounts of zinc nitrate. The Zn²⁺ ion was partially substituted for the Ca²⁺ ion position in the HAp lattice, and hence, the obtained samples had changed little in crystallinity, particle size, and specific surface area. Adsorption of bovine serum albumin (BSA) and β₂-microglobulin (β₂-MG) in solutions containing both BSA and β₂-MG was examined. As the Zn²⁺ ion content in the apatites increased, the adsorbed amount of BSA was almost constant, whereas that of β₂-MG increased.     

Dried leaves from rocky mountain plants decrease infestation by stored-product beetles

Leaves of two highly aromatic plants,Artemisia tridentata (Nutt.) andMonarda fistulosa L., prepared according to a patented process, inhibited oviposition by the Mexican bean weevil,Zabrotes subfasciatus (Boheman), in beans at concentrations less than 1% w/w. Both plant species were less effective against the rice weevil,Sitophilus oryzae L., in wheat, with onlyM. fistulosa exhibiting any concentration-dependent activity. The maximal control achieved against this species was less than 50% at 3% w/w. Two less aromatic plant species,Balsamorhiza sagittata (Pursh.) Nutt. andGeranium viscosissimum Fisch. and Mey., caused only low levels of inhibition against both insect species. Volatiles probably caused the response toA. tridentata andM. fistulosa, while the asymptotic concentration dependence for the less volatile plant material was likely caused by behavioral factors related to the physical presence of foreign particulate matter in the foodstuff. Chemical analysis indicated that most of the volatile components from the dried leaf material from all species were terpenoids, with camphor (9.7 mg/g) and 1,8-cineole (4.0 mg/g) being most abundant inA. tridentata and carvacrol (26.3 mg/g) being most abundant inM. fistulosa.Portions of this research were conducted by the U.S. Department of Agriculture. All programs and services of the U.S. Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status, or handicap. This article reports the results of research only. Mention of a proprietary product does not constitute an endorsement or a recommendation for its use by USDA.     

核电循环冷却水一氯胺反应动力学规律

核电站循环冷却水系统的消毒是核电水系统的研究重点．以法国丹皮尔核电站冷却塔模型为研究对象,进行一氯胺消毒剂的消耗动力学研究,确定以天然原水为循环水介质的一氯胺消耗动力学符合一级反应的动力学模型,其反应速率常数为0．002min^-1;以人工模拟投加Fe^3＋进行一氯胺消耗分析表明,Fe^3＋对一氯胺的消耗无显著影响．     

Applications of Low Field NMR Techniques in the Characterization of Oil Sand Mining,Extraction and Upgrading Processes

A number of techniques have previously been developed that use low field nuclear magnetic resonance (NMR) relaxometry for conventional and heavy oil reservoir characterization. In the current work, the adaptation of these algorithms for use in the oil sands industry is presented. NMR based methods have been developed for identification of water and bitumen content in ore and froth samples. Consistent algorithms have been used to analyze over 500 ore samples and 50 froth samples from the Athabasca oil sands in northern Alberta. Preliminary analyses are shown, with applications for in‐situ fluid determination using NMR logging tools and improved process control in oil sands processing plants.