5,671 research outputs found
Laser Hair Removal: Comparative Study of Light Wavelength and its Effect on Laser Hair Removal
For some people, hirsuteness (having excess body hair) can be an embarrassing problem. Many attempts have been made to find a solution to these problems, including electrolysis, tweezing, shaving, and waxing. However, most of these solutions are painful, are not useful in treating large areas of skin, or are not permanent. Laser hair removal stands out amongst these other methods as a permanent method of reducing hirsuteness that can cover large areas of the body, such as the chest or the legs. While laser hair removal is a widely used technology, few studies have explored the physical aspects of why it works so well. More specifically, there is a significant lack of computer models that show how temperature profiles look inside the hair and surrounding skin. Using the physical properties and dimensions of hair, we constructed a model of the hair that approximates how actual hair resides in the skin. Using COMSOL Multiphysics, we tested this model with five different lasers of varying wavelengths in order to determine the relationship between laser wavelength and temperature in the hair. Using a laser pulse duration of 0.01 seconds (10 milliseconds), we found a positive correlation between wavelength and temperature, with all wavelengths except the lowest (595 nm) achieving a temperature above the threshold temperature required for hair destruction. In addition, while all lasers caused a temperature rise in the surrounding skin, the extent of thermal damage was minimal. However, since we could not find physical properties of the hair follicle itself, we were forced to approximate those properties using the hair shaft properties, ultimately leading us to treat the follicle and shaft as one entity. This is a slight limitation with our design. Regardless, we have provided a greater understanding of the physiological temperatures involved in hair removal, and have reinforced the fact that laser hair removal can be a safe method and effective method for treating hirsuteness by showing that hair follicles can be heated to a temperature that kill them by using lasers, and that this heating does not severely or irreparably damage surrounding skin
What Does Economics Assume About People’s Knowledge? Who knows?
The purpose of the paper is to explore, from an assessment viewpoint, the ideas below. Economics, as a social science, has always considered sets of individuals with assumed characteristics, namely the level of knowledge, although in an implicit way in most of the cases. In this sense, an influential approach in Economics assumed that society, as a global set of individuals, was characterised by a certain level of knowledge that, indeed, could be associated with the one of its representative agent. In fact, an attentive recall of the evolution of these matters in Economics will immediately recognise that, since the very first economic models of the government, it was assumed that the level of knowledge of society, represented by a set of voters, was not the same as the one of the agent being elected, i.e. the government. The irrelevance of the difference in the level of knowledge of economic agents was soon abandoned after some seminal works of Hayek and Friedman. More recently, the viewpoint of Economics has changed by focusing on the characteristics (e.g. knowledge) of individuals, who may interact in sub-sets of society. From this point of view is clearly relevant, given the close connection with the assumed level of knowledge, to distinguish the adaptive behaviour from the rational one, as well as the full rational from the bounded rationality behaviour by people. Quite recent developments in the Economics of Knowledge, i.e. the so-called learning models, have been considered as more realistic approaches to model the process by which individuals acquire knowledge, for instance from other individuals that are, themselves, acquiring knowledge
Phase 1 Study of the E-Selectin Inhibitor GMI 1070 in Patients with Sickle Cell Anemia
Background\ud
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Sickle cell anemia is an inherited disorder of hemoglobin that leads to a variety of acute and chronic complications. Abnormal cellular adhesion, mediated in part by selectins, has been implicated in the pathophysiology of the vaso-occlusion seen in sickle cell anemia, and selectin inhibition was able to restore blood flow in a mouse model of sickle cell disease.\ud
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Methods\ud
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We performed a Phase 1 study of the selectin inhibitor GMI 1070 in patients with sickle cell anemia. Fifteen patients who were clinically stable received GMI 1070 in two infusions.\ud
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Results\ud
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The drug was well tolerated without significant adverse events. There was a modest increase in total peripheral white blood cell count without clinical symptoms. Plasma concentrations were well-described by a two-compartment model with an elimination T1/2 of 7.7 hours and CLr of 19.6 mL/hour/kg. Computer-assisted intravital microscopy showed transient increases in red blood cell velocity in 3 of the 4 patients studied.\ud
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Conclusions\ud
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GMI 1070 was safe in stable patients with sickle cell anemia, and there was suggestion of increased blood flow in a subset of patients. At some time points between 4 and 48 hours after treatment with GMI 1070, there were significant decreases in biomarkers of endothelial activation (sE-selectin, sP-selectin, sICAM), leukocyte activation (MAC-1, LFA-1, PM aggregates) and the coagulation cascade (tissue factor, thrombin-antithrombin complexes). Development of GMI 1070 for the treatment of acute vaso-occlusive crisis is ongoing
On tree amplitudes with gluons coupled to gravitons
In this paper, we study the tree amplitudes with gluons coupled to gravitons.
We first study the relations among the mixed amplitudes. With BCFW on-shell
recursion relation, we will show the color-order reversed relation,
-decoupling relation and KK relation hold for tree amplitudes with gluons
coupled to gravitons. We then study the disk relation which expresses mixed
amplitudes by pure gluon amplitudes. More specifically we will prove the disk
relation for mixed amplitudes with gluons coupled to one graviton. Using the
disk relation and the properties of pure gluon amplitudes, the color-order
reversed relation, -decoupling relation and KK relation for mixed
amplitudes can also be proved. Finally, we give some brief discussions on
BCJ-like relation for mixed amplitudes.Comment: 33pages,no figur
Pancreas and islet cell transplantation
Currently, for the patient with type 1 diabetes, a definitive treatment without resorting to the use of exogenous insulin can be achieved only with pancreas or islet cell transplantation. These means of restoring β-cell mass can completely maintain essentially normal long-term glucose homeostasis, although the need for powerful immunosuppressive regimens limits their application to only a subgroup of adult patients. Apart from the shortage of donors that has limited all kinds of transplantation, however, the widespread use of β-cell replacement has been precluded until recently by the drawbacks associated with both organ and islet cell transplantation. Although the study of recurrence of diabetes has generated attention, the fundamental obstacle to pancreas and islet transplantation has been, and remains, the alloimmune response. With a better elucidation of the mechanisms of alloengraftment achieved during the last 3 years, the stage has been set for further advances
PD1-based DNA vaccine amplifies HIV-1 GAG-specific CD8+ T cells in mice
Viral vector-based vaccines that induce protective CD8+ T cell immunity can prevent or control pathogenic SIV infections, but issues of preexisting immunity and safety have impeded their implementation in HIV-1. Here, we report the development of what we believe to be a novel antigen-targeting DNA vaccine strategy that exploits the binding of programmed death-1 (PD1) to its ligands expressed on dendritic cells (DCs) by fusing soluble PD1 with HIV-1 GAG p24 antigen. As compared with non-DC-targeting vaccines, intramuscular immunization via electroporation (EP) of the fusion DNA in mice elicited consistently high frequencies of GAG-specific, broadly reactive, polyfunctional, long-lived, and cytotoxic CD8+ T cells and robust anti-GAG antibody titers. Vaccination conferred remarkable protection against mucosal challenge with vaccinia GAG viruses. Soluble PD1-based vaccination potentiated CD8+ T cell responses by enhancing antigen binding and uptake in DCs and activation in the draining lymph node. It also increased IL-12-producing DCs and engaged antigen cross-presentation when compared with anti-DEC205 antibody-mediated DC targeting. The high frequency of durable and protective GAG-specific CD8+ T cell immunity induced by soluble PD1-based vaccination suggests that PD1-based DNA vaccines could potentially be used against HIV-1 and other pathogens.published_or_final_versio
Post-traumatic growth as positive personality change: developing a measure to assess within-person variability
Earlier work has defined post-traumatic growth (PTG) as positive personality change, but measurement of this construct has relied almost exclusively on cross-sectional and retrospective assessments. The aim of this study was to use an experience-sampling procedure to measure the extent to which PTG manifested in individuals’ everyday lives after a recent highly stressful or traumatic adverse event (compared to a control group). In doing so, we developed a state measure of PTG. The factor structure of state PTG was comparable to trait PTG, there was significant variability in individuals’ PTG from moment-to-moment, but individuals’ trait PTG was unrelated to their state PTG. Moreover, individuals who had experienced a recent adversity did not differ from control participants on state PTG
D-brane anomaly inflow revisited
Axial and gravitational anomaly of field theories, when embedded in string
theory, must be accompanied by canceling inflow. We give a self-contained
overview for various world-volume theories, and clarify the role of smeared
magnetic sources in I-brane/D-brane cases. The proper anomaly descent of the
source, as demanded by regularity of RR field strengths H's, turns out to be an
essential ingredient. We show how this allows correct inflow to be generated
for all such theories, including self-dual cases, and also that the mechanism
is now insensitive to the choice between the two related but inequivalent forms
of D-brane Chern-Simons couplings. In particular, SO(6)_R axial anomaly of d=4
maximal SYM is canceled by the inflow onto D3-branes via the standard minimal
coupling to C_4. We also propose how, for the anomaly cancelation, the four
types of Orientifold planes should be coupled to the spacetime curvatures, of
which conflicting claims existed previously.Comment: 41 pages, references updated; version to appear in JHE
Monodromy--like Relations for Finite Loop Amplitudes
We investigate the existence of relations for finite one-loop amplitudes in
Yang-Mills theory. Using a diagrammatic formalism and a remarkable connection
between tree and loop level, we deduce sequences of amplitude relations for any
number of external legs.Comment: 24 pages, 6 figures, v2 typos corrected, reference adde
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