915 research outputs found

    A retrospective evaluation of subsurface monopolar radiofrequency for lifting of the face, neck, and Jawline

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    BACKGROUND Subsurface monopolar radiofrequency (SMRF) has emerged as a new method for reducing skin laxity via the controlled delivery of thermal energy below the skin using a radiofrequency probe. OBJECTIVE To evaluate the overall efficacy of the treatment and satisfaction ratings of subjects who underwent a single SMRF treatment to the face, neck, or jawline (or some combination). MATERIALS AND METHODS A retrospective, single-center study was conducted in which data were obtained via subject follow-ups at 90 and 180 days posttreatment. RESULTS A total of 35 subjects, 6 men and 29 women, underwent a single SMRF treatment. Overall, 77% of subjects reported improvement, and 64% reported satisfaction with the treatment site at Day 180 posttreatment. CONCLUSION Subsurface monopolar radiofrequency represents an effective modality to achieve skin tightening of the face, neck, and jawline. The data suggest that there is an energy delivery threshold, above which a higher percentage of subjects report satisfaction. Analysis of treatments parameters suggests an optimal treatment time and tissue temperature that should be achieved to maximize results. © 2016 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc

    Vanadium Doping Effect on Multifunctionality of SnO2 Nanoparticles

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     In the present study, tin oxide (SnO2) nanoparticles were synthesized by a precursor polymeric method. The obtained nanoparticles were doped with vanadium. The samples were characterized by powder XRD, TEM, optical UV and EPR studies. XRD and TEM showed the rutile crystal structure and its revealed that the lattice cell parameters and particles size were decreased with dopant level. Optical and EPR data confirmed that the doped V enters into SnO2 and distorted the host material symmetry. The films sensing characteristics have been studied from the aspect of doping level of sensing material and microstructure. It is found that V doping on SnO2 enhance sensor sensitivity towards CO gas. The results demonstrated that V doping can improving numerous applications which the SnO2 response is maximized

    Fornix deep brain stimulation enhances acetylcholine levels in the hippocampus

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    Deep brain stimulation (DBS) of the fornix has gained interest as a potential therapy for advanced treatment-resistant dementia, yet the mechanism of action remains widely unknown. Previously, we have reported beneficial memory effects of fornix DBS in a scopolamine induced rat model of dementia, which is dependent on various brain structures including hippocampus. To elucidate mechanisms of action of fornix DBS with regard to memory restoration, we performed c-Fos immunohistochemistry in the hippocampus. We found that fornix DBS induced a selective activation of cells in the CA1 and CA3 subfields of the dorsal hippocampus. In addition, hippocampal neurotransmitter levels were measured using microdialysis before, during and after 60 min of fornix DBS in a next experiment. We observed a substantial increase in the levels of extracellular hippocampal acetylcholine, which peaked 20 min after stimulus onset. Interestingly, hippocampal glutamate levels did not change compared to baseline. Therefore, our findings provide first experimental evidence that fornix DBS activates the hippocampus and induces the release of acetylcholine in this region.Publisher PDFPeer reviewe

    Coarse-graining of cellular automata, emergence, and the predictability of complex systems

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    We study the predictability of emergent phenomena in complex systems. Using nearest neighbor, one-dimensional Cellular Automata (CA) as an example, we show how to construct local coarse-grained descriptions of CA in all classes of Wolfram's classification. The resulting coarse-grained CA that we construct are capable of emulating the large-scale behavior of the original systems without accounting for small-scale details. Several CA that can be coarse-grained by this construction are known to be universal Turing machines; they can emulate any CA or other computing devices and are therefore undecidable. We thus show that because in practice one only seeks coarse-grained information, complex physical systems can be predictable and even decidable at some level of description. The renormalization group flows that we construct induce a hierarchy of CA rules. This hierarchy agrees well with apparent rule complexity and is therefore a good candidate for a complexity measure and a classification method. Finally we argue that the large scale dynamics of CA can be very simple, at least when measured by the Kolmogorov complexity of the large scale update rule, and moreover exhibits a novel scaling law. We show that because of this large-scale simplicity, the probability of finding a coarse-grained description of CA approaches unity as one goes to increasingly coarser scales. We interpret this large scale simplicity as a pattern formation mechanism in which large scale patterns are forced upon the system by the simplicity of the rules that govern the large scale dynamics.Comment: 18 pages, 9 figure

    The early evolution of young massive clusters: The kinematic history of NGC6611 / M16

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    In the first few Myr the massive stars dynamically interact, produce runaways and affect the initial binary population. Observing and interpreting the dynamics of young massive clusters is key to our understanding of the star formation process and predicting the outcome of stellar evolution. We have studied NGC6611 in the Eagle Nebula (M16), a young massive cluster hosting 19 O stars. We used Gaia EDR3 data to determine the membership, age, cluster dynamics and the kinematics of the massive stars including runaways. The membership analysis yields 137 members located at a mean distance of 1706 ±\pm 7 pc. The colour - absolute magnitude diagram reveals a blue and a red population of pre-main-sequence stars, consistent with two distinct populations of stars. In line with earlier studies, the youngest population has a mean extinction AVA_V = 3.6 ±\pm 0.1 mag and an age = 1.3 ±\pm 0.2 Myr, while the older population of stars has a mean extinction AVA_V = 2.0 ±\pm 0.1 mag and an age = 7.5 ±\pm 0.4 Myr. The latter population is more spatially extended than the younger generation of stars. We argue that most of the OB stars belong to the younger population. We identify 8 runaways originating from the center of NGC6611, consistent with the dynamical ejection scenario. We show that ~ 50% of the O stars have velocities comparable to or greater than the escape velocity. These O stars can be traced back to the center of NGC6611 with kinematic ages ranging from 0 to 2 Myr. This suggests that dynamical interactions played an important role in the early evolution of NGC6611, which is surprising considering the low current stellar density. Comparing this to simulations of young massive clusters, the required initial radius of 0.1-0.5 pc is not consistent with that of NGC6611. The O stars could have initially formed in wide binaries and possibly harden through dynamical interactions.Comment: replaced with accepted version to A&A. 28 pages, 15 figure

    The Clumping Transition in Niche Competition: a Robust Critical Phenomenon

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    We show analytically and numerically that the appearance of lumps and gaps in the distribution of n competing species along a niche axis is a robust phenomenon whenever the finiteness of the niche space is taken into account. In this case depending if the niche width of the species σ\sigma is above or below a threshold σc\sigma_c, which for large n coincides with 2/n, there are two different regimes. For σ>sigmac\sigma > sigma_c the lumpy pattern emerges directly from the dominant eigenvector of the competition matrix because its corresponding eigenvalue becomes negative. For σ</sigmac\sigma </- sigma_c the lumpy pattern disappears. Furthermore, this clumping transition exhibits critical slowing down as σ\sigma is approached from above. We also find that the number of lumps of species vs. σ\sigma displays a stair-step structure. The positions of these steps are distributed according to a power-law. It is thus straightforward to predict the number of groups that can be packed along a niche axis and it coincides with field measurements for a wide range of the model parameters.Comment: 16 pages, 7 figures; http://iopscience.iop.org/1742-5468/2010/05/P0500

    Gauge invariance and finite width effects in radiative two-pion tau lepton decay

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    The contribution of the rho^{\pm} vector meson to the tau -> pi pi nu gamma decay is considered as a potential source for the determination of the magnetic dipole moment of this light vector meson. In order to keep gauge-invariance of the whole decay amplitude, a procedure similar to the fermion loop-scheme for charged gauge bosons is implemented to incorporate the finite width effects of the rho^{\pm} vector meson. The absorptive pieces of the one-loop corrections to the propagators and electromagnetic vertices of the rho^{\pm} meson and W^{\pm} gauge boson have identical forms in the limit of massless particles in the loops, suggesting this to be a universal feature of spin-one unstable particles. Model-dependent contributions to the tau -> pi pi nu gamma decay are suppressed by fixing the two-pion invariant mass distribution at the rho meson mass value. The resulting photon energy and angular distribution is relatively sensitive to the effects of the rho magnetic dipole moment.Comment: 22 pages, 4 postscript figures, references and comments on relevance of perturbative treatment of rho electromagnetic vertex are added, accepted for pub. in Phys. Rev.

    Acute toxicity of the aqueous-methanolic Moringa oleifera (Lam) leaf extract on female Wistar albino rats

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    Background: Herbal preparations are widely assumed to be safe on oral administration and therefore the documentation of the toxic potential of some herbal concoctions used as medicine and nutrients is limited. Moringa oleifera (MO) is a plant that is gaining tremendous popularity in rural communities in Kenya as a means of offsetting nutritional and medicinal needs. However, very little is known about the safety of the plant on oral administration. Thus, the aim of the current study was to assess the biochemical and histological changes in the liver following the administration of an aqueous-methanolic (AQ-ME) MO leaf extract in female Wistar albino rats.Methods: Acute oral toxicity study on the AQ-ME MO leaf extract was conducted by the use of the limit test dose of the up and down procedure (OECD guideline number 425) with slight modifications. Briefly, ten (10) healthy, nulliparous, non-pregnant female Wistar strain albino rats aged               8-12 weeks and weighing 180±20 grams were used for the study. These animals were randomly selected into two groups; control and treatment group each having five (5) animals. They were then labelled to enable identification and control group animals were orally administered with physiological buffer saline once daily over a 48-hour period. The five (5) rats in the treatment group were dosed orally one at a time and once daily with a 2000 mg/kg dose of the AQ-ME MO leaf extract to determine the median lethal dose over a 48 hour period. Blood was then collected and used to prepare serum for biochemical analysis of aspartate amino transferase (AST), alanine amino transferase (ALT) and total bilirubin (TB) which are important biomarkers of liver dysfunction. Biochemical assays of these enzymes were performed using the method of the International Federation of Clinical Chemists (IFCC). Death was used as an endpoint, livers harvested and used to prepare transverse sections for histopathological examination. These sections were stained using the haematoxylin and eosin (H&E) method and observed for pathological changes using an optical microscope.Results: A 2000 mg/kg oral dose of AQ-ME MO leaf extract caused a significant (p0.05) increase in the mean levels of total bilirubin in the treatment group relative to the control group. On the other hand, the extract caused a non-significant (p>0.05) decrease in the mean levels of ALT in the treatment group relative to the control. The post mortem analysis of the hepatic index (liver to body weight ratio) revealed that there was a non-significant increase (p>0.05) in the hepatic index of the treatment group relative to the control. However, the transverse liver sections of treatment group animals showed mild distortions in the architecture of liver cells.Conclusions: Based on these results, the LD50 of the AQ-ME MO leaf extract was found to be >2000 mg/kg in female wistar albino rats

    1001–24 Local Delivery of Urokinase to Porcine Coronary Arteries Using the Localmed Infusion Sleeve

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    Local Delivery of thrombolytic agents may reduce thrombus formation after balloon angioplasty. The Localmed Infusion Sleeve enables localized infusion of urokinase to be performed at the time of balloon angioplasty without the need for catheter exchange.MethodsBalloon angioplasty was performed on 13 coronary arteries of 5 pigs at 4 atmospheres with a balloon to artery ratio of approximately 1.1 to 1. After angioplasty the Infusion Sleeve was advanced over the dilatation balloon and the balloon was reinflated to 2 atmospheres to appose the sleeve to the vessel wall. 50,000 Units (8 cc) of 123l-urokinase was infused through the microperforations in the sleeve for 10 seconds by a computer controlled pump. The coronaries were then excised and counted in a gamma counter.ResultsConclusions(1) The Localmed Infusion Sleeve enables drug infusion to be uncoupled from balloon dilatation. (2) Successful delivery of Urokinase to the vessel wall may be achieved using this device without the need for catheter exchange. (3) Persistence of urokinase within the vessel wall occurs after local delivery
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