276 research outputs found

    Four bioactive compounds isolated from the stem of Anethum sowa L. and their bioactivities

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    Anethum sowa L., (a well-known herb in folk medicine, has a greater medicinal significance due to its diversified activities such as antioxidant, antimicrobial and antispasmodic activity. Very few bioactive compounds have been reported from this species. Our study focused on the isolation, structure elucidation and bioactivity assay of the compounds. In the present work, 6-hydroxy-1, 3-dimethoxy-7-methyl-xanthen-9-one (AS-1) from dichloromethane extract and scopoletin (AS-2), 1, 3, 4-trimethoxy-xanthen-9-one (AS-3), graveolone (AS-4) from ethyl acetate extract of stem of A. sowa were isolated from the stem as well as the plant for the first time. All the characterizations and chemical structures of the compounds were determined by extensive modern spectroscopic techniques such as ultraviolet (UV), infrared (IR), mass, Nuclear Magnetic Resonance (NMR) spectrophotometer. Moreover, the cytotoxic, antimicrobial and antioxidant activity of AS-2, AS-3 and AS-4 were assessed. AS-2 exhibited significant activity against Salmonella typhi while mild antifungal activity against Aspergillus niger. Furthermore AS-3 revealed significant antifungal activity against Sacharomyces cerevacae as well as antibacterial activity against Salmonella typhi. Besides AS-4 exhibited moderate antibacterial activity against Bacillus megaterium. In addition AS-2, AS-3 and AS-4 presented mild cytotoxic with respect to positive control (Vincristine sulphate) while AS-3 exhibited moderate antioxidant activity as compared to positive control (Ascorbic acid)

    On the Downlink Coverage Performance of RIS-Assisted THz Networks

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    This letter provides a stochastic geometry (SG)-based coverage probability (CP) analysis of an indoor terahertz (THz) downlink assisted by a single reconfigurable intelligent surface (RIS) panel. Specifically, multiple access points (AP) deployed on the ceiling of a hall (each equipped with multiple antennas) need to serve multiple user equipment (UE) nodes. Due to presence of blockages, a typical UE may either get served via a direct link, the RIS, or both links (the composite link). The locations of the APs and blockages are modelled as a Poisson point process (PPP) and SG framework is utilized to compute the CP, at a reference UE for all the three scenarios. Monte-Carlo simulation results validate our theoretical analysis.Comment: Extended Arxiv version of submitted paper to IEEE Communications Letter

    A cytogenic monitoring approach of hospital workers occuptionally exposed to ionizing radiations using micronucleus assay

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    Background: The objective of this study was to determine chromosomal damage in occupational workers of the radiation department from three different hospitals, Faisalabad, Pakistan exposed for a long term to ionizing radiations using micronucles (MN) assay. A comparison between exposed and non-exposed subjects (controlled) of same age exhibited a significant an increase in the number of micronuclei in occupational workers. MN frequency increases with an increase in age and duration of exposure in both sexes but higher in females.Materials and Methods: The study was conducted at the District Head Quarter Hospital (DHQ), Punjab Institute of Nuclear Medicine (PINUM) and Allied Hospital, Faisalabad, Pakistan. The total 145 subjects were selected from these hospitals. The subjects were divided into two groups. The control group (N= 40) (20 males and 20 females) of healthy subjects (no exposure) and the second group of subjects (N=105) (68 males and 37 females) subjects of occupational workers who were indirectly exposed to radiation. Blood samples (2ml) were collected in sodium heparinised vaccutainer tubes through venipuncture from both the groups. Disposable syringes were used for this purpose. For the evaluation of MN yield, slides were prepared by following the method of Jorge et al. (2004).Results: A significant difference in micro nuclear induction was observed between the occupational subjects and the control subjects and as well as in females and in males (P < 0.01). Females are more vulnerable to ionizing radiation than males. In females, MN yield was two times higher than males. MN frequency was increased with an increase in age and duration of exposure in both sexes, but higher in females and may be due to an increase in chromosomal loss in hospital workers. There is an individual response to the physical noxa, depending on sex, age and exposure. Smoking and drinking habits do not have a significant effect in increasing the number of MN in occupationally exposed workers.Conclusion: It was concluded that females are more vulnerable to ionizing radiations than males. MN test can be used as a biomarker with a predictive value for the estimation in occupationally exposed subjects.Key Words: Radiations; Hospital workers; Sex; Micronucleus assay; Chromosomal damag

    Gender-related discourses in corporate annual reports: an exploratory study on the Bangladeshi companies

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    Purpose The purpose of this study is to explore the gender-related discourses in the annual reports of the listed companies in Bangladesh. Design/methodology/approach To fulfill this objective, a sociological discourse analysis (SDA) of the gender-related texts in the annual reports of Bangladeshi companies (listed in the Dhaka Stock Exchange) was conducted. Sandberg and Holmlund’s (2015) organizational impression management tactics (description, praise, admission, defense and writing styles) was applied as the analytical framework of SDA. The findings of the study were interpreted from a triangulation of two different theories: legitimacy theory and impression management theory. Findings The study suggests that the companies in Bangladesh are disclosing gender-related information to a limited extent. They provide some information in relation to equal opportunities, business activities targeted to women and corporate contribution to women’s welfare. Most of these gender-related discourses are rhetorical in nature. The companies used various impression management tactics such as description, praise, positive writing style, vague writing style and emotional writing style. Research limitations/implications This study is exploratory in nature and focuses on cross-sectional data. Thus, it does not identify the trend of corporate gender reporting over the years. Practical implications At the policy level, the findings revealed a need for reporting guidelines for gender narratives. Although there is a global gender reporting guideline as proposed under global reporting initiative, there is no local guideline in Bangladesh. Our findings suggest that in the absence of proper directives, companies presented facts and figures rhetorically and qualitatively. Social implications Our findings provide valuable insights for the companies in assisting the Government of Bangladesh to deal with the prevailing gender inequality and achieved gender-related sustainable development goals. It is argued that the government should take more interest in corporate social responsibility activities (such as promoting gender equality) and introduce legislation and guidelines for social accounting. Originality/value This is one of the very few studies that illustrate the corporate gender reporting of a developing economy – Bangladesh. To make a unique contribution to corporate gender disclosure, the study has drawn its analysis from a triangulation of the impression management and the legitimacy perspectives. Also, the use of SDA for annual report analysis has informed the readers about “how” the corporate narratives are presented in the annual reports rather than “what” issues are disclosed as commonly done in content analysis

    Surface structure of the Ag-In-(rare earth) complex intermetallics

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    We present a study of the surface structure of the Ag-In-RE (RE: rare-earth elements Gd, Tb, and Yb) complex intermetallics using scanning tunneling microscopy and low-energy electron diffraction. The surface of the Ag-In-Yb approximant prepared by sputter-annealing methods under ultrahigh-vacuum conditions produces a flat (100) surface with no facets. However, the Ag-In-Gd and Ag-In-Tb 1/1 approximants, which have a surface miscut of about 12∘ relative to the (100) plane, develop surface facets along various crystallographic directions. The structure of each facet can be explained as a truncation of the rhombic triacontahedral clusters, i.e., the main building blocks of these systems. Despite their differences in atomic structure, symmetry, and density, the facets show common features. The facet planes are In rich. The analysis of the nearest-neighbor atom distances suggests that In atoms form bonds with the RE atoms, which we suggest is a key factor that stabilizes even low-density facet planes

    Results from the United Arab Emirates 2022 report card on physical activity for children and adolescents

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    Objective: The United Arab Emirates (UAE) 2022 Report Card provides a systematic evaluation of the physical activity (PA) levels of children and adolescents in the UAE. Methods: The 2022 Report Card utilized data from 2017 to 2021 to inform 10 core PA indicators that were common to the Global Matrix 4.0. Results: One in five (19%) UAE school children achieved the recommended amount of moderate-to-vigorous PA (i.e. ≥60 min/d; Total Physical Activity Grade F). Less than 1% of school children used active transport to and from school (Active Transportation Grade F). One in four (26%) secondary school children achieved the recreational screen time recommendations (i.e. ≤2 h/d; Sedentary Behaviours Grade D-). A quarter of adults reported achieving the recommended PA level (i.e. ≥150 min of moderate-intensity PA per week, or equivalent) (Family and Peers Grade D-). All school children are taught physical education (PE) by a specialist with at least a bachelor\u27s degree in PE; however, the duration of weekly PE classes varied between schools (School Grade A-). The UAE Government has invested significant funds and resources into developing and implementing strategies and facilities that will increase PA across the entire population (Government Grade B+). Organised Sport and Physical Activity, Active Play, Physical Fitness, and Community and Environment indicators were graded ‘Incomplete’ (INC) due to a lack of available data. Conclusions: Overall, PA levels remain low and sedentary behaviours remain high amongst UAE children and adolescents. The UAE Government has sustained investment in further developing PA opportunities for all children and adults which should translate to increased PA and health improvements at a population level

    Pentacene islands grown on ultra-thin SiO2

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    Ultra-thin oxide (UTO) films were grown on Si(111) in ultrahigh vacuum at room temperature and characterized by scanning tunneling microscopy. The ultra-thin oxide films were then used as substrates for room temperature growth of pentacene. The apparent height of the first layer is 1.57 +/- 0.05 nm, indicating standing up pentacene grains in the thin-film phase were formed. Pentacene is molecularly resolved in the second and subsequent molecular layers. The measured in-plane unit cell for the pentacene (001) plane (ab plane) is a=0.76+/-0.01 nm, b=0.59+/-0.01 nm, and gamma=87.5+/-0.4 degrees. The films are unperturbed by the UTO's short-range spatial variation in tunneling probability, and reduce its corresponding effective roughness and correlation exponent with increasing thickness. The pentacene surface morphology follows that of the UTO substrate, preserving step structure, the long range surface rms roughness of ~0.1 nm, and the structural correlation exponent of ~1.Comment: 15 pages, 4 figure
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