Body Shaping and Volume Restoration: The Role of Hyaluronic Acid

Driven by the rising popularity of minimally invasive techniques, the demand for cosmetic procedures is increasing. Cosmetic body-shaping procedures can be categorized into those that remove tissue and those that add volume. This review focuses on the latter of these categories, particularly on the use of resorbable hyaluronic acid gels specifically developed for minimally invasive volume enhancement. Pilot studies of hyaluronic acid involving its injection to contour various body deformities and its recent use in female breast augmentation are discussed. Injectable hyaluronic acid is effective and well tolerated. It represents an attractive treatment option for volume restoration or augmentation by providing predictable long-lasting results after minimally invasive administration. Alternative treatment options for volume enhancement also are summarized including fat transfer, silicone implants, and the use of injectable nonresorbable products such as silicone, polyalkylimide, and polyacrylamide gels. As patients continue to opt for nonsurgical procedures that offer predictable results, the development of minimally invasive products such as hyaluronic acid is increasingly important

The role of highly oxygenated organic molecules in the Boreal aerosol-cloud-climate system

Over Boreal regions, monoterpenes emitted from the forest are the main precursors for secondary organic aerosol (SOA) formation and the primary driver of the growth of new aerosol particles to climatically important cloud condensation nuclei (CCN). Autoxidation of monoterpenes leads to rapid formation of Highly Oxygenated organic Molecules (HOM). We have developed the first model with near-explicit representation of atmospheric new particle formation (NPF) and HOM formation. The model can reproduce the observed NPF, HOM gas-phase composition and SOA formation over the Boreal forest. During the spring, HOM SOA formation increases the CCN concentration by similar to 10 % and causes a direct aerosol radiative forcing of -0.10 W/m(2). In contrast, NPF reduces the number of CCN at updraft velocities <0.2 m/s, and causes a direct aerosol radiative forcing of +0.15 W/m(2). Hence, while HOM SOA contributes to climate cooling, NPF can result in climate warming over the Boreal forest.Peer reviewe

The effect of acid-base clustering and ions on the growth of atmospheric nano-particles

The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.Peer reviewe

The expanded skin in breast reconstruction : An experimental and clinical study

The expanded skin in breast reconstruction An experimental and clinical study MICHAEL OLENIUS Department of Plastic and Reconstructive Surgery and Department of Neuroscience Karolinska Hospital and Karolinska Institute, Stockholm, SwedenTissue expansion has become one of the routine methods in breast recon- struction. It is a safe and easy method, which is well accepted by the patient. Clinical reports are numerous, but morphological changes are still not thoroughly investigated. The main question in tissue expansion is, whether the gain of skin is the result of formation of new skin or from stretching of adjacent tissues. The changes in thickness of the epidermis and the dermis have been evaluated by several authors. However, the majority of reports on morphological and biomechanical alterations are based on animal models. All investigations in the present thesis were performed in humans, subjected to breast recon- struction with tissue expansion. Mastectomized women who had their breasts reconstructed by means oftissue expansion, were included in a prospective and consecutive study.Breasts were overexpanded to double the volume of the final prosthesis.Clinical evaluation was performed by two independent examiners. There wasa low rate of complications and patients were satisfied in 82% of the cases.Capsular contraction incidence was 28%. The disadvantage of the method isthe long time necessary for reconstruction. Mitotic activity of the basal cell layer of the epidermis, where new cells areproduced, was studied with autoradiography. There was a significant rise inlabeled cells induced by expansion, implicating formation of new cells. Thiswas accentuated by the fact that insulin-like growth factors I and II, studied byimmunohistochemical technique, showed increased levels after expansion inthe basal layer of the epidermal keratinocytes. The thickness of the epidermis was studied before, during and six monthsafter expansion. Epidermal thickness showed maximal values during expan-sion and values before and after did not differ significantly from each other. The total skin thickness and biomechanical properties (elasticity, hysteresisand distensibility) were investigated in patients who were slowly and rapidlyexpanded. Measurements of skin thickness were performed with ultrasoundtechnique at five occasions before, during and after expansion. Skin thicknesswas decreased during the expansion procedure with a minimum at maximalexpansion. Two weeks after implantation there was an increase in thickness.Six months and 4 years after completed reconstruction, however, epidermiswas thinner than before reconstruction. There was no difference between thegroups of rapidly and slowly expanded breasts. Biomechanical properties were studied with a suction chamber device.The different properties were altered during expansion to a minor extent, butno difference between groups was noted.Key words Tissue expansion, capsular contraction, rapid and slow expansion, mitotic activity,epidermal thickness, skin thickness, collagen diameter, skin properties, insulin-like growth factorStockholm 1995 ISBN 91-628-1823-

Atmospherically Relevant Chemistry and Aerosol box model - ARCA box (version 1.2)

Atmospherically Relevant Chemistry and Aerosol box model ARCA box (v.1.2.0) is a zero-dimensional process model with focus in atmospheric chemistry and submicron aerosol processes, including cluster formation. The model has a comprehensive graphical user interface, allowing for detailed configuration and documentation of the simulation settings, flexible model input and output visualization. Additionally, the graphical interface contains tools for module customization and input data acquisition. These properties – customizability, ease of implementation and repeatability – make ARCA invaluable tool for any atmospheric scientist who needs a view on the complex atmospheric aerosol processes. ARCA is based on previous models (MALTE-BOX, ADiC and ADCHEM) but the code has been fully rewritten and reviewed. The chemistry module incorporates the Master Chemical Mechanism (MCMv3.3.1) and Peroxy Radical Autoxidation Mechanism (PRAM) but can use any compatible chemistry scheme. ARCA’s aerosol module couples the ACDC (Atmospheric Cluster Dynamics Code) in its particle formation module, and the discrete particle size representation includes the fully stationary and fixed grid, moving average methods. ARCA calculates the gas-particle partitioning of low-volatility organic vapours for any number of compounds included in the chemistry, and the Brownian coagulation of the particles. The model has parametrisations for vapour and particle wall losses but accepts user supplied time and size-resolved input. ARCA is written in Fortran and Python (user interface and supplementary tools), can be installed on any of the three major operating systems and is licensed under GPLv3. ARCA 1.2.0 is the submission version of the GMD manuscript, subject to discussion. For latest ARCA version, see the website of the Multi-Scale Mod­el­ling group in University of Helsinki

New particle formation and growth from methanesulfonic acid, trimethylamine and water

New particle formation from gas-to-particle conversion represents a dominant source of atmospheric particles and affects radiative forcing, climate and human health. The species involved in new particle formation and the underlying mechanisms remain uncertain. Although sulfuric acid is commonly recognized as driving new particle formation, increasing evidence suggests the involvement of other species. Here we study particle formation and growth from methanesulfonic acid, trimethylamine and water at reaction times from 2.3 to 32 s where particles are 2-10 nm in diameter using a newly designed and tested flow system. The flow system has multiple inlets to facilitate changing the mixing sequence of gaseous precursors. The relative humidity and precursor concentrations, as well as the mixing sequence, are varied to explore their effects on particle formation and growth in order to provide insight into the important mechanistic steps. We show that water is involved in the formation of initial clusters, greatly enhancing their formation as well as growth into detectable size ranges. A kinetics box model is developed that quantitatively reproduces the experimental data under various conditions. Although the proposed scheme is not definitive, it suggests that incorporating such mechanisms into atmospheric models may be feasible in the near future