53 research outputs found

    Circular Polarization from Gamma-ray Burst Afterglows

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    We investigate the circular polarization (CP) from Gamma-Ray Burst (GRB) afterglows. We show that a tangled magnetic field cannot generate CP without an ordered magnetic field because there is always an oppositely directed field, so that no handedness exists. This implies the observation of CP could be a useful probe of an ordered field, which carries valuable information on the GRB central engine. By solving the transfer equation of polarized radiation, we find that the CP reaches 1% at radio frequencies and 0.01% at optical for the forward shock, and 10-1% at radio and 0.1-0.01% at optical for the reverse shock.Comment: 12 pages, 3 figure

    OPC-67683, a Nitro-Dihydro-Imidazooxazole Derivative with Promising Action against Tuberculosis In Vitro and In Mice

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    BACKGROUND: Tuberculosis (TB) is still a leading cause of death worldwide. Almost a third of the world's population is infected with TB bacilli, and each year approximately 8 million people develop active TB and 2 million die as a result. Today's TB treatment, which dates back to the 1970s, is long and burdensome, requiring at least 6 mo of multidrug chemotherapy. The situation is further compounded by the emergence of multidrug-resistant TB (MDR-TB) and by the infection's lethal synergy with HIV/AIDS. Global health and philanthropic organizations are now pleading for new drug interventions that can address these unmet needs in TB treatment. METHODS AND FINDINGS: Here we report OPC-67683, a nitro-dihydro-imidazooxazole derivative that was screened to help combat the unmet needs in TB treatment. The compound is a mycolic acid biosynthesis inhibitor found to be free of mutagenicity and to possess highly potent activity against TB, including MDR-TB, as shown by its exceptionally low minimum inhibitory concentration (MIC) range of 0.006–0.024 μg/ml in vitro and highly effective therapeutic activity at low doses in vivo. Additionally, the results of the post-antibiotic effect of OPC-67683 on intracellular Mycobacterium tuberculosis showed the agent to be highly and dose-dependently active also against intracellular M. tuberculosis H37Rv after a 4-h pulsed exposure, and this activity at a concentration of 0.1 μg/ml was similar to that of the first-line drug rifampicin (RFP) at a concentration of 3 μg/ml. The combination of OPC-67683 with RFP and pyrazinamide (PZA) exhibited a remarkably quicker eradication (by at least 2 mo) of viable TB bacilli in the lung in comparison with the standard regimen consisting of RFP, isoniazid (INH), ethambutol (EB), and PZA. Furthermore, OPC-67683 was not affected by nor did it affect the activity of liver microsome enzymes, suggesting the possibility for OPC-67683 to be used in combination with drugs, including anti-retrovirals, that induce or are metabolized by cytochrome P450 enzymes. CONCLUSIONS: We concluded that based on these properties OPC-67683 has the potential to be used as a TB drug to help combat the unmet needs in TB treatment

    Factors associated with the development of ocular candidiasis and ocular prognosis with echinocandin therapy for candidemia

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    Abstract Purpose To evaluate the factors associated with the development of ocular candidiasis (OC) and ocular prognosis with echinocandin therapy for candidemia. Methods The medical records of 56 consecutive patients with a positive blood culture for Candida species between November 2016 and October 2019 were retrospectively reviewed. Information on patient characteristics, isolated Candida species, treatment details for candidemia, and ocular findings were extracted to identify factors associated with OC development. Results The leading pathogen of candidemia was Candida albicans (C.albicans) (41.1%). Of 56 patients, 18 (32.1%) were diagnosed with chorioretinitis, categorized as either probable (8 patients) or possible OC (10 patients). There was no case of endophthalmitis with vitritis. The incidence of probable OC was not significantly different between the groups treated with echinocandins and other antifungal drugs (15.2% vs. 11.1%, p = 1.00). In all probable OC cases, systemic antifungal therapy was switched from echinocandins to azoles, and no case progressed to endophthalmitis. A multivariate logistic analysis revealed that female sex (adjusted odds ratio [aOR], 8.93; 95% confidence interval [CI], 1.09–72.9) and C. albicans (aOR, 23.6; 95% CI, 1.8–281) were independent factors associated with the development of probable OC. Conclusion One-seventh of patients with candidemia developed probable OC. Given the evidence of female and C. albicans as the factors associated with OC development, careful ophthalmologic management is required with these factors, especially in candidemia. Although echinocandins had no correlation with OC development and did not lead to the deterioration of ocular prognosis, further investigation is required

    Efficacy and visual prognostic factors of intravitreal bevacizumab as needed for macular edema secondary to central retinal vein occlusion

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    textabstractAbstract This paper analyzes the verdicts of various film organizations that annually present awards to motion pictures and investigates whether they award/nominate the same movies in a given year. This research disputes previous findings which reported a high level of agreement between those juries, by the means of reliability analysis and the Cronbach's Alpha composite. Arguments were raised for why these earlier findings were flawed and why the use of Cronbach's Alpha is problematic. Different aspects of consensus are discussed after which a new measure (߀) is introduced. This is followed by a detailed comparison between particular juries with regard to the percentage share of their decisions that award the most successful (chosen by multiple other juries as well) and the least successful (uniquely awarded) films. This measure shows how often a singular jury decides in line with the others and how much does it stray from the consensus. The paper also broadens the theoretical discussions about the reasons for (not) expecting a consensus to arise between various expert juries. It argues that by adopting a cultural economic perspective we become aware of various reasons, most importantly competition between the award events and the juries tend towards a lower level of consensus

    Predictive factors of metamorphopsia after reduced-fluence photodynamic therapy in patients with central serous chorioretinopathy with good baseline visual acuity.

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    This retrospective study was conducted to investigate the predictive factors associated with metamorphopsia after reduced-fluence photodynamic therapy (RFPDT) in patients with central serous chorioretinopathy (CSC) with good baseline visual acuity. A total of 36 eyes of 36 consecutive patients with resolved CSC after RFPDT and best-corrected visual acuity (BCVA) better than 1.0 (logarithm of the minimal angle of resolution (logMAR) 0) at baseline were examined. Metamorphopsia was measured using M-CHARTS at 12 months after RFPDT. An average of the horizontal and vertical M-CHARTS scores was applied for defining the extent of metamorphopsia. The association between M-CHARTS score at 12 months after RFPDT and clinical parameters (age, sex, duration of symptoms, BCVA, and findings of optical coherence tomography (OCT)) was investigated at baseline or 12 months after RFPDT. The M-CHARTS score at 12 months correlated significantly with duration of symptoms (P = 0.005), baseline outer nuclear layer (ONL) thickness (P = 0.009), central foveal thickness (CFT) (P = 0.001) at 12 months, and ONL thickness (P = 0.001) at 12 months after RFPDT. In the multivariate analysis of baseline-related factors, thinner ONL thickness before RFPDT (P = 0.010) was significantly associated with large metamorphopsia at 12 months after RFPDT in CSC patients with good baseline BCVA. Baseline ONL thickness may be a useful predictive factor of metamorphopsia after RFPDT in CSC patients with good baseline BCVA
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