- 著者
- Muzahir Ali BALOCH Aziz Ahmed QURESHI Abdul WAHEED Muhammad ALI Nawab ALI Muhammad TUFAIL Saima BATOOL Muhammad AKRAM Poonam IFTIKHAR Hamza QAYYUM Shahid MANZOOR Hameed Ahmed KHAN
- 出版者
- Journal of Radiation Research Editorial Committee
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.53, no.3, pp.411-421, 2012 (Released:2012-06-01)
- 参考文献数
- 55
- 被引用文献数
- 20
The Khewra Salt Mines, the second largest salt mines in the world, are located 160 km south of Islamabad, the capital of Pakistan. Around 1000 workers are involved in the removal of salt from these mines. More than 40,000 visitors come annually to see the mines. The visitors and workers are directly exposed to the internal and external radiological hazards of radon and gamma rays in these mines. The general public is affected by the intake of the salt containing the naturally occurring radionuclides. Therefore the concentration of radon (222Rn) in the Khewra Salt Mines and activity concentrations of the naturally occurring radionuclides in the salt samples from these mines were measured. Both active and passive techniques were employed for the measurement of radon with Radon Alpha Detector (RAD-7) and SSNTD respectively. The concentration of 222Rn was 26 ± 4 Bq m–3 measured by the active method while 43 ± 8 Bq m–3 was measured by the passive method. The activity concentration of the radionuclides was measured using gamma ray spectrometry with HPGe detector. The mean activity of 40K in salt samples was found to be 36 ± 20 Bq kg–1 and the concentration of 226Ra and 232Th in the salt samples was below the detection limits. Gamma radiation hazard was assessed in terms of the external gamma dose from salt slabs and the rooms made of salt and the annual effective dose due to gamma radiation. The exposure to radon daughters, annual effective dose and excessive lifetime cancer risk due to radon in the mines were estimated. The mean annual effective dose due to an intake of 40K from the salt was calculated as 20.0 ± 11.1 μSv, which is lower than the average annual effective dose rate of 0.29 mSv, received by the ingestion of natural radionuclides. Due to the low concentration values of primordial radionuclides in the salt and radon (222Rn) in the mines, a ‘low level activity measurement laboratory' is suggested to be established in these mines.
- 著者
- Ahsana Dar Shaheen Faizi Sabira Naqvi Talat Roome Sadia Zikr-ur-Rehman Muhammad Ali Sadiqa Firdous Syed Tarique Moin
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Biological and Pharmaceutical Bulletin (ISSN:09186158)
- 巻号頁・発行日
- vol.28, no.4, pp.596-600, 2005 (Released:2005-04-01)
- 参考文献数
- 36
- 被引用文献数
- 112 184
Mangiferin, 2-β-D-glucopyranosyl-1,3,6,7-tetrahydroxy-9H-xanthen-9-one, obtained directly from methanolic extracts of Bombax ceiba leaves in substantial amounts demonstrated strong antioxidant activity (EC50 5.8±0.96 μg/ml or 13.74 μM) using DPPH assay comparable to rutin, commonly used as antioxidant for medical purposes. The acetyl and cinnamoyl derivatives were found to be less active than mangiferin whereas, methyl and 3,6,7-trimethylether tetraacetate derivatives were inactive implying that for antioxidant activity, free hydroxyl groups and catechol moiety are essential. Moreover, mangiferin showed hepatoprotective activity against carbon tetrachloride induced liver injury further supporting the free radical scavenging property in the in vivo system. Additionally, plant extracts and mangiferin failed to exhibit acute anti-inflammatory activity whereas, it displayed significant analgesic effect in acetic acid-induced writhing and hot plate tests in mice. Using naloxone, it was revealed that plant extracts induced analgesia was independent of opioid receptor, whereas, mangiferin demonstrated significant interaction with it at peripheral site with a slight contribution at the neuronal level.