142 research outputs found

    Tetrameric DABCO™-Bromine: an Efficient and Versatile Reagent for Bromination of Various Organic Compounds

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    Tetrameric DABCO™-bromine is a powerful brominating agent but shows reasonable selectivity with certain substrates. The selective bromination for activated aromatic compounds and alkenes is reported. Synthesis of -bromo ketones and nitriles has also been achieved by using this reagent and the results are also reported. All products reported were obtained in good to excellent yields.KEYWORDS: Tetrameric DABCO™-Bromine, TDB, solid supports, bromination, -bromination, 1,2-dibromo compounds, bromohydrin

    Geometric morphometric analysis of the molars in three species of the genus Mus (Mus) (Rodentia, Muridae) based on the outline method

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    The relatively new technique of outline-based geometric morphometrics was applied in a study of the variation in the shape of the upper and lower molars among 122 mice, belonging to one species from Iran (Mus musculus) and two species from Europe (Mus macedonicus, Mus spicilegus). Differentiation of specimens based on molar shape was highly dependent on the details of the shape information. Among molars, the second upper and first lower molars are better at separating the species. This method provides a useful way to distinguish species based on the outline of their molars.Keywords: shape variation; upper and lower molars; mice; Iran; Europe

    Determination of developmental stages of embryo in the sea urchin, Echinometra mathaei

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    Sea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed in beakers and were incubated at 29°C and a salinity of 39 ppt until embryos reached the pluteus stage. The developmental stages of embryos and the timing of each stage including cleavage, morulae, blastula, gastrula, prism and pluteus larvae were studied under the microscope. Our results showed that after 30 hours from fertilization time, the embryos developed to pluteus larvae. E. mathaei had the shorter development time in comparison to the other Sea Urchin species. Therefore, it may be appropriate as a model organism in biological researches

    Responsibility attitude in a sample of Iranian obsessive-compulsive patients

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    Background: The study of distorted beliefs about responsibility attitude and interpretation has become the central theme in Salkovskis' (1985) and Rachman and Hodgson's (1980) models of Obsessive-Compulsive Disorder (OCD). Aims: The aim of this research is to assess the responsibility attitude in Iranian OCD patients. Methods: Twenty OCD patients were selected through available sampling from the case referred to psychology clinics. Two other patient groups comprised of 20 non-OCD anxiety disorder patients and 20 non-clinical participants were also chosen as comparison groups. All participants completed the Responsibility Attitude Scale (RAS) and Responsibility Interpretation Questionnaire (RIQ). Results: Analyses revealed statistically significant differences between OCD group and comparison groups on both RAS and RIQ. In addition, both RAS and RIQ scores were associated with the severity of OCD assessed by the Yale-Brown scale. Conclusions: These findings suggest that responsibility attitude and interpretations are the prominent features of OCD in Iranian patients and are associated with the severity of illness. Copyright © 2005 Sage Publications

    Studies of Scattering, Reflectivity, and Transmitivity in WBAN Channel: Feasibility of Using UWB

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    The Wireless Personal Area Network (WPAN) is one of the fledging paradigms that the next generation of wireless systems is sprouting towards. Among them, a more specific category is the Wireless Body Area Network (WBAN) used for health monitoring. On the other hand, Ultra-Wideband (UWB) comes with a number of desirable features at the physical layer for wireless communications. One big challenge in adoption of UWB in WBAN is the fact that signals get attenuated exponentially. Due to the intrinsic structural complexity in human body, electromagnetic waves show a profound variation during propagation through it. The reflection and transmission coefficients of human body are highly dependent upon the dielectric constants as well as upon the frequency. The difference in structural materials such as fat, muscles and blood essentially makes electromagnetic wave attenuation to be different along the way. Thus, a complete characterization of body channel is a challenging task. The connection between attenuation and frequency of the signal makes the investigation of UWB in WBAN an interesting proposition. In this paper, we study analytically the impact of body channels on electromagnetic signal propagation with reference to UWB. In the process, scattering, reflectivity and transmitivity have been addressed with analysis of approximate layer-wise modeling, and with numerical depictions. Pulses with Gaussian profile have been employed in our analysis. It shows that, under reasonable practical approximations, the human body channel can be modeled in layers so as to have the effects of total reflections or total transmissions in certain frequency bands. This could help decide such design issues as antenna characteristics of implant devices for WBAN employing UWB

    Transplacental transmission of SARS-CoV-2 infection: A case report from Iran

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    We report a case of SARS-CoV-2 vertical transmission through the placenta in a neonate whose mother had non-M3 acute myeloid leukemia (AML) that was complicated with Covid-19 in the last trimester. Viral load in nasopharyngeal swabs from mother and neonate were high. Real-time PCR of the fetal side of the placenta was positive for SARS-CoV-2, which makes it possible to consider this case as a congenital case of SARS-CoV-2 infection that is transmitted through vertical transmission. © 2020, Author(s)

    Portuguese validation of the Internet Addiction Test: An empirical study

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    Abstract Background and aims Research into Internet addiction (IA) has increased greatly over the last decade. Despite its various definitions and general lack of consensus regarding its conceptualisation amongst researchers, instruments for measuring this phenomenon have proliferated in a number of countries. There has been little research on IA in Portugal and this may be partly due to the absence of standardised measurement tools for assessing IA. Methods This study attempted to address this issue by adapting a Portuguese version of the Internet Addiction Test (IAT) via a translation-back translation process and Confirmatory Factor Analysis in a sample of 593 Portuguese students that completed a Portuguese version of the IAT along with questions related to socio-demographic variables. Results The findings suggested that the IAT appears to be a valid and reliable instrument for measuring IA among Portuguese young adults as demonstrated by its satisfactory psychometric properties. However, the present findings also suggest the need to reword and update some of the IAT's items. Prevalence of IA found in the sample was 1.2% and is discussed alongside findings relating to socio-demographic correlates. Limitations and implications of the present study are also discussed. Conclusions The present study calls for a reflection of the IAT while also contributing to a better understanding of the basic aspects of IA in the Portuguese community since many health practitioners are starting to realise that Internet use may pose a risk for some individuals
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