789 research outputs found

    Transcaruncular Medial Wall Orbital Decompression: An Effective Approach for Patients with Unilateral Graves Ophthalmopathy

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    Purpose. To evaluate the reduction in proptosis, incidence of postoperative diplopia, and postoperative globe symmetry after transcaruncular medial wall decompression in patients with unilateral Graves ophthalmopathy. Methods. Retrospective review of 16 consecutive patients who underwent unilateral transcaruncular medial wall orbital decompression from 1995 to 2007. The diagnosis of Graves ophthalmopathy was based on history and clinical findings including proptosis, lagophthalmos, lid retraction, motility restriction, and systemic thyroid dysfunction. Results. The mean reduction in proptosis was 2.3 mm. The mean difference in exophthalmometry preoperatively between the two eyes in each patient was 3.1 mm whereas postoperatively the mean difference was 1.1 mm (P = 0.0002). Eleven of 16 patients (69%) had 1 mm or less of asymmetry postoperatively. There was no statistically significant difference in the incidence of diplopia pre and postoperatively (P = 1.0). Conclusions. Medial wall orbital decompression is a safe and practical surgical approach for patients with unilateral Graves orbitopathy. The procedure carries a low risk of morbidity and yields anatomic retrusion of the globe that is comparable to other more invasive methods and may yield more symmetric postoperative results

    A comprehensive overview on Kratom

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    Kratom (Mitragyna speciosa Korth) is a tropical tree, indigenous to South East Asia. Historically, the plant is locally used as a stimulant, a remedy in traditional medicine and in social context. Imported to Western countries, Kratom is classified as a novel psychoactive substance (NPS). A systematic review of the literature on Mitragyna speciosa and its main constituents was carried by our international multidisciplinary group. Results were qualitatively analysed in three main areas of interest: in-vitro and preclinical data on pharmacology and behavioral effects, laboratoristic techniques for identification/characterization, epidemiological/toxicological reports on humans. At present, there is no systematic data on the prevalence of Kratom use in all the native countries, but it seems to be considerable. In South-East Asia, Kratom, even if banned, might be still considered a better option than other illicit drugs, an alternative opioid treatment, a “natural” remedy with no real social stigma attached to its consumption. In parallel, this ethno-drug seems to be popular in Western countries, largely unregulated, easily available on the Internet. Kratom pharmacology appears to be complex, with many alkaloids involved. The subjective effects in humans are very peculiar and seem to be dose-dependent, ranging from psycho-stimulant to sedative-narcotic. Available data on Kratom suggest caution: this psychoactive plant could exhibit a serious harmful potential. Kratom use seems to be associated with drug dependency, development of withdrawal symptoms, craving, serious adverse effects and life-threatening effects in a multidrug-intoxicating scenario. On the other hand, its anxyiolitic, antidepressant and analgesic properties deserve to be further studied

    Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper Based Catalysts for CO2 Hydrogenation

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    Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H2 in the temperature range 25–500 °C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 °C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 °C, before the onset of reduction to Cu at 190 °C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 °C. Further reduction to Cu from 190 °C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 °C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 °C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 °C and retained a significantly active surface

    Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper-Based Catalysts for CO2 Hydrogenation

    Get PDF
    Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H2 in the temperature range 25–500 °C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 °C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 °C, before the onset of reduction to Cu at 190 °C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 °C. Further reduction to Cu from 190 °C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 °C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 °C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 °C and retained a significantly active surface

    Pericentromeric satellite repeat expansions through RNA-derived DNA intermediates in cancer

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    Aberrant transcription of the pericentromeric human satellite II (HSATII) repeat is present in a wide variety of epithelial cancers. In deriving experimental systems to study its deregulation, we observed that HSATII expression is induced in colon cancer cells cultured as xenografts or under nonadherent conditions in vitro, but it is rapidly lost in standard 2D cultures. Unexpectedly, physiological induction of endogenous HSATII RNA, as well as introduction of synthetic HSATII transcripts, generated cDNA intermediates in the form of DNA/RNA hybrids. Single molecule sequencing of tumor xenografts showed that HSATII RNA-derived DNA (rdDNA) molecules are stably incorporated within pericentromeric loci. Suppression of RT activity using small molecule inhibitors reduced HSATII copy gain. Analysis of whole-genome sequencing data revealed that HSATII copy number gain is a common feature in primary human colon tumors and is associated with a lower overall survival. Together, our observations suggest that cancer-associated derepression of specific repetitive sequences can promote their RNA-driven genomic expansion, with potential implications on pericentromeric architecture
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