4,449 research outputs found

    Laser Hair Removal: Comparative Study of Light Wavelength and its Effect on Laser Hair Removal

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    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

    Study of Stress, Housing Program Use, and Nursing Usage Among Homeless in Chicago

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    Homelessness places people at risk of stressors that translate into stress and subsequently affect their health. Using Neuman Systems Model as a framework to identify modalities for nursing intervention among stressors and health problems of homeless people, this study compared stress levels among homeless people from three different homeless housing program types, investigated variables that predict the presence of stress among homeless, identified the degree of self-reported contact homeless people had with nurses, and measured to what extent nurses are preferred as health care providers by homeless people. This was accomplished through a cross-sectional, secondary data analysis of data from the evaluation study for the Chicago Plan to End Homelessness. Instruments utilized included the Perceived Stress Scale (PSS) and BPTSD-6. The sample size was 398 participants aged 18 years or older who were English speaking and clients of a homeless housing program in Chicago. The data was analyzed using ANOVA, multiple regression, odds ratios, and chi-square tests. The results of the study suggested that there were no differences in stress between participants of housing program types, and the variables prompting further assessment of stress in homeless patients included living with an adult child, availability of family and friends, psychiatric problem perception and burden, and PTSD. The results of the study also suggested that nurses were second to physicians in being seen as well as preferred by homeless participants

    Chronic Hepatitis B Prevalence Among Foreignā€Born and U.S.ā€Born Adults in the United States, 1999ā€2016

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154388/1/hep30831-sup-0001-Supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154388/2/hep30831.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154388/3/hep30831_am.pd

    Fabrication of biodegradable poly(lactic acid) particles in flow-focusing glass capillary devices

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    Monodisperse poly(dl-lactic acid) (PLA) particles with a diameter in the range from 12 to 100 9m were fabricated in flow focusing glass capillary devices by evaporation of dichloromethane (DCM) from emulsions at room temperature. The dispersed phase was 5% (w/w) PLA in DCM containing a small amount of Nile red and the continuous phase was 5% (w/w) poly(vinyl alcohol) in reverse osmosis water. Particle diameter was 2.7 times smaller than the size of the emulsion droplet template indicating that the particle porosity was very low. SEM images revealed that the majority of particle pores are in the sub-micron region but in some instances these pores can reach 3 9m in diameter. Droplet diameter was influenced by the flow rates of the two phases and the entry diameter of the collection capillary tube; droplet diameters decreased with increasing values of the flow rate ratio of the dispersed to continuous phase to reach constant minimum values at 40-60 % orifice diameter. At flow rate ratios less than 5, jetting can occur, giving rise to large droplets formed by detachment from relatively long jets (~10 times longer than droplet diameter)

    What Does Economics Assume About Peopleā€™s Knowledge? Who knows?

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    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

    Elevated Perioperative Transaminase Level Predicts Intrahepatic Recurrence in Hepatitis B-related Hepatocellular Carcinoma After Curative Hepatectomy

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    OBJECTIVEWe aimed to evaluate the role of elevated perioperative alanine aminotransferase (ALT) as a surrogate marker of hepatitis activity in determining the risk of recurrence and survival in hepatitis B-related hepatocellular carcinoma (HCC) after curative hepatectomy.METHODSA retrospective review of the hepatectomy database was performed and 142 patients were found who had hepatitis B-related HCC from January 2001 to March 2006. Their ALT levels preoperatively and 1 month, 3 months, and 6 months postoperatively were recorded. The risk factors for recurrence and prognostic factors of survival were analysed.RESULTSAn elevated perioperative ALT level (p = 0.021), multiple tumour nodules in the resected specimen (p < 0.001), and a tumour size greater than 5 cm (p = 0.001) were significant independent risk factors for tumour recurrence. The latter two factors were also independent prognostic factors for overall survival and disease-free survival. An elevated ALT level was an independent prognostic factor for disease-free survival (p = 0.025).CONCLUSIONAn elevated perioperative ALT level, which reflects increased hepatitis activity, is an independent risk factor for intrahepatic recurrence of hepatitis B-related HCC. It is also associated with a poorer disease-free survival rate

    Expression profile of inflammatory cytokines in aqueous from glaucomatous eyes

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    PURPOSE: To determine the proinflammatory cytokine profile of aqueous humor from glaucomatous eyes. METHODS: Aqueous humor samples were prospectively collected from 38 eyes (26 primary open angle glaucoma [POAG] and 12 primary angle closure glaucoma [PACG] eyes) of 37 medically treated glaucoma patients and 23 cataract subjects recruited in an institutional setting in this case-controlled study. The main outcome measure was to quantify the levels of 29 inflammatory cytokines in the aqueous of glaucoma and cataract subjects using a multiplexed cytokine analysis. Data on patient demographics, duration of glaucoma, preoperative intraocular pressure (IOP) as well as duration of anti-glaucoma therapy were also collected for correlation analysis. RESULTS: Mean duration of glaucoma was 53.8 months (range 1-360 months). Aqueous obtained from the glaucoma patients showed increased concentration of interleukin (IL)-9 (p=0.032), IL-12 (p=0.003), interferon (IFN)-Ī± (p=0.034), IFN-Ī³ (p=0.002), monokine induced by interferon-gamma (MIG or CXCL9) (p=0.006), and IL-10 (p=0.050), compared to the cataract group. The POAG group had higher IL-12 (p=0.011), IFN-Ī³ (p=0.005), and CXCL9 (p=0.047) levels than controls, while the PACG group had higher interleukin-8 (CXCL8) (p=0.015) and CXCL9 (p=0.023) levels than the controls. No significant correlation was observed between aqueous cytokine level and preoperative IOP and duration of glaucoma. Duration of topical Timolol and Alphagan therapy correlated negatively with CXCL8 (r=-0.588, p=0.035), respectively. CONCLUSIONS: Primary glaucoma is associated with an aqueous inflammatory response and this is different between POAG and PACG groups. Duration of glaucoma treatment may have an effect on cytokine profile in the aqueous.Published versio

    Phase 1 Study of the E-Selectin Inhibitor GMI 1070 in Patients with Sickle Cell Anemia

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    Background\ud \ud 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 \ud Methods\ud \ud 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 \ud Results\ud \ud 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 \ud Conclusions\ud \ud 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
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