Natural radioactivity contents in tobacco and radiation dose induced from smoking

One of the causative factors for cancer-inducing mechanisms in humans is radioactive elements present in tobacco leaves used in the manufacture of cigarettes. Smoking of tobacco and its products increases the internal intake and radiation dose due to naturally occurring radionuclides that are considered to be one of the most significant causes of lung cancer. In this work, different commercial types of cigarettes, cigar and moassel were collected from market. Naturally occurring radionuclides (226)Ra and (214)Bi ((238)U series), (228)Ac and (228)Ra ((232)Th series), (40)K and man-made (137)Cs were measured in tobacco using gamma-ray spectrometer. Results show that the average concentrations of (238)U, (232)Th and (40)K were 4.564, 3.940 and 1289.53 Bq kg(-1), respectively. This reflects their origin from the soil by root uptake and fertilisers used in the cultivation of tobacco plants. Concentration of (137)Cs was 0.348 Bq kg(-1) due to root uptake or deposition onto the leaf foliage. For smokers, the annual effective dose due to inhalation of (238)U varied from 49.35 to 139.40 μSv(-1) (average 104.27 μSv y(-1)), while of (232)Th from 23.86 to 111.06 μSv y(-1) (average 65.52 μSv y(-1)). The annual effective dose resulting from (137)Cs was varied from 10.96 to 24.01 nSv y(-1) (average 19.41 nSv y(-1)).     

Aquifer characteristics and water quality of Miocene–Pleistocene sediments, Kuwait

Al-Atraf is one of the water well fields of Kuwait supplying Kuwait City with the brackish groundwater obtained from the Kuwait Group aquifer of Miocene–Pleistocene age. The study determined the hydrogeological and hydrochemical characteristics of the groundwater in order to identify the major chemical processes that influence the groundwater quality of the study area. The results of the aquifer test analyses indicate that the Kuwait Group is a confined to semi-confined aquifer, with a transmissivity ranging between 62 and 321 m²/day. The flow net analysis implied that the groundwater moves from southwest to northeast. The estimated transmissivity values agree well with those calculated from the aquifer test. The results of the chemical analyses data of the Al-Atraf field show that the groundwater is mainly brackish, of NaCl and Na₂SO₄ water types. The groundwater is undersaturated with respect to halite, gypsum and anhydrite and supersaturated with respect to quartz, dolomite and calcite in the direction of groundwater flow. The average Pco₂ of the groundwater is higher than the Pco₂ of the earths atmosphere indicating that the groundwater is supplied with CO₂ during the infiltration processes and dissolves the carbonate minerals under closed-system conditions.     

Hydrogeological and Hydrochemical Study of the Al-Shagaya Field-F, Kuwait

The study area, Al-Shagaya Field-F, is located at the south western part of Kuwait and includes twenty-seven production water wells, tapping the Kuwait Group aquifer. The main objectives of this study were to identify the aquifer type, determine its properties, outline the geological factors and the hydrochemical processes that control the quality of the groundwater of the study area, and to assess the water quality of the Kuwait Group aquifer. Analyses of aquifer test data revealed that the Kuwait Group aquifer acts as a semi-confined to confined aquifer, with a range of transmissivity values between 103 and 1,198 m²/day. The initial water level ranges from 70 to 146 m (M.S.L). The estimated quantity of groundwater entering the study area is about 12,950 m³/day. The chemical analyses show that the groundwater of the study area is a brackish water type, with total dissolved solids ranging from 3,586 to 5,334 mg/l. The aquifer salinity increases in the direction of regional flow towards the NE. The average pH value is 7.7 and the average electrical conductivity is 5,349 s/cm. Groundwater is highly concentrated with Na⁺, Ca²⁺, Cl^- and SO₄^2- and is depleted in HCO₃^- and Mg²⁺ ions. It is characterized by secondary salinity, where the alkaline earths exceed the alkalies and strong acids exceed weak acids. Three groundwater chemical types are recognized: NaCl, Na₂SO₄ and CaCl₂. The NaCl water type is the most abundant in the study area. The main genetic types of water are: MgCl₂ and Na₂SO₄. It is found that the groundwater is oversaturated with respect to aragonite and calcite and undersaturated with respect to anhydrite, gypsum, halite and dolomite. A comparison of the hydrochemical coefficients of Na⁺/Cl^-, SO₄^2-/Cl^- and Ca²⁺/Mg²⁺ in the study area with those of seawater and river water shows that the groundwater of the study area is a mixture of marine and continental water.     

Approach to Separate Sand from Gravel for Bed-Load Transport Calculations in Streams with Bimodal Sediment

The bed material found in gravel-bed streams is nonuniform in terms of grain size and can typically be classified as unimodal or bimodal. The latter type of sediment distribution is usually represented by two modes, one of sand size and another of gravel. For this case, the movement of one mode becomes nonlinearly influenced by the other. As a result, the presence of the two modes in a bimodal material complicates the calculation of bed-load transport rates. The present study proposes an approach to separate the calculation of bed-load transport rates for bimodal materials into two independent fractions of sand and gravel, thereby rendering the bed sediment into two unimodal components. This approach is accomplished by decoupling the two fractions through scaling the reference Shields stresses of the sand and gravel modes to match the value of the mode of unimodal materials. Consequently, the contribution of each fraction to bed load can be estimated using a suitable relation derived for unimodal materials. Laboratory and field bed-load data available in the literature are used to examine the validity of the overall approach.     

Bond–slip models for double strap joints strengthened by CFRP

This paper presents the results of a series of tension tests on CFRP bonded steel plate double strap joints. The main aim of this research is to provide detailed understanding of bond characteristics using experimental and numerical analysis of strengthened double strap joints under tension. A parametric study has been performed by numerical modelling with the variables of CFRP bond lengths, adhesive maximum strain and adhesive layer thicknesses. Finally, bond–slip models are proposed for three different types of adhesives within the range of the parametric study.     

Synthesis of polyaniline nanostructures in micellar solutions

Polymerization of aniline nanoparticles was carried out in aqueous micellar solutions of surfactants, including anionic (sodium dodecyl sulfate), nonionic (nonyl phenol ethoxylate), and cationic (cetyltrimethyl ammonium bromide) surfactants. The size and morphology of these synthesized PANI nanoparticles strongly depended on the structure of the surfactants used in the formation of micelles, as shown by transmission electron microscopy. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction were used in the characterization of the synthesized PANI nanoparticles. The PANI nanoparticles revealed enhanced conductivity compared to conventional bulk PANI. In addition PANI–poly(methyl methacrylate) (PMMA) nanocomposites were synthesized. The results revealed that the PMMA nanoparticles retarded thermal decomposition and enhanced the conductivities compared with pristine PANI nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Halting Tumor Progression via Novel Non-Hydroxamate Triazole-Based Mannich Bases MMP-2/9 Inhibitors; Design,Microwave-Assisted Synthesis,and Biological Evaluation

Matrix metalloproteinases (MMPs) are key signaling modulators in the tumor microenvironment. Among MMPs, MMP-2 and MMP-9 are receiving renewed interest as validated druggable targets for halting different tumor progression events. Over the last decades, a diverse range of MMP-2/9 inhibitors has been identified starting from the early hydroxamic acid-based peptidomimetics to the next generation non-hydroxamates. Herein, focused 1,2,4-triazole-1,2,3-triazole molecular hybrids with varying lengths and decorations, mimicking the thematic features of non-hydroxamate inhibitors, were designed and synthesized using efficient protocols and were alkylated with pharmacophoric amines to develop new Mannich bases. After full spectroscopic characterization the newly synthesized triazoles tethering Mannich bases were subjected to safety assessment via MTT assay against normal human fibroblasts, then evaluated for their potential anticancer activities against colon (Caco-2) and breast (MDA-MB 231) cancers. The relatively lengthy bis-Mannich bases 15 and 16 were safer and more potent than 5-fluorouracil with sub-micromolar IC₅₀ and promising selectivity to the screened cancer cell lines rather than normal cells. Both compounds upregulated p53 (2–5.6-fold) and suppressed cyclin D expression (0.8–0.2-fold) in the studied cancers, and thus, induced apoptosis. 15 was superior to 16 in terms of cytotoxic activities, p53 induction, and cyclin D suppression. Mechanistically, both were efficient MMP-2/9 inhibitors with comparable potencies to the reference prototype hydroxamate-based MMP inhibitor NNGH at their anticancer IC₅₀ concentrations. 15 (IC₅₀ = 0.143 µM) was 4-fold more potent than NNGH against MMP-9 with promising selectivity (3.27-fold) over MMP-2, whereas 16 was comparable to NNGH. Concerning MMP-2, 16 (IC₅₀ = 0.376 µM) was 1.2-fold more active than 15. Docking simulations predicted their possible binding modes and highlighted the possible structural determinants of MMP-2/9 inhibitory activities. Computational prediction of their physicochemical properties, ADMET, and drug-likeness metrics revealed acceptable drug-like criteria.     

Hydrochemical Processes and Environmental Isotopic Study of Groundwater in Kuwait

Abstract

The present paper studies the hydrochemical processes and the isotopic characteristics of the main aquifers, the Kuwait Group and Dammam aquifers in the State of Kuwait. The water chemical types are dominantly NaCl and Na₂SO₄ in the Kuwait Group aquifer and Na₂SO₄, CaSO₄, and NaCl in the Dammam Limestone aquifer. The groundwater of the Kuwait Group aquifer is supersaturated with respect to quartz and calcite, and near saturation with respect to aragonite, but under-saturated with respect to anhydrite, dolomite, gypsum, and halite. While the groundwater of the Dammam aquifer is strongly under-saturated with respect to anhydrite, halite, and gypsum and is supersaturated with respect to quartz, dolomite, aragonite, and calcite. The saturation indices of the calcite and dolomite are increased in the direction of flow from southwest toward north-northeast. Al-Rawdhatain and Umm Al-Aish groundwater samples lie near the meteoric water line. They represent the effect of recharge by rainfall during pluvial period. The brackish palaeo-groundwater of the Dammam aquifer has low values of δ¹⁸O (?4.5 per mil) and δD (?35 per mil), which reveal that these waters are related to the palaeo-water from the cool wet period in the eastern Arabia 11,000 to 60,000 years B.P. The investigated brackish groundwater samples showed that the deuterium excess values are much lower than that of the Mediterranean areas. This may suggest that the evaporation was a prevailing process before the infiltration to the aquifers.     

Synthesis of 9-Hydroxy-1H-Benzo[f]chromene Derivatives with Effective Cytotoxic Activity on MCF7/ADR,P-Glycoprotein Inhibitors,Cell Cycle Arrest and Apoptosis Effects

β-Enaminonitriles bearing 9-hydroxy-1H-benzo[f]chromene moiety was synthesized. The targeted compounds were evaluated for their anti-proliferative activity against three human tumor cell lines, PC-3, SKOV-3 and HeLa, and the active cytotoxic compounds were further evaluated against cancer cells, MCF-7/ADR, and two normal cell lines, HFL-1 and WI-38. Few compounds were assigned to be the most potent derivatives against PC-3, SKOV-3 and HeLa cell lines in comparison with Vinblastine and Doxorubicin. Several compounds possessed a relatively good potency against MCF-7/ADR cells as compared with Doxorubicin and were tested as a P-gp inhibitor. Moreover, the halogenated substituents, 2,4-F₂, 2,3-Cl₂, 2,5-Cl₂ and 3,4-Cl_2; have good potency against P-gp-mediated MDR in MCF-7/ADR as compared with Doxorubicin. Meanwhile, Rho123 accumulation assays revealed that few compounds effectively inhibited P-pg and efflux function. In addition, certain derivatives induced apoptosis and an accumulation of the treated MCF-7/ADR cells in the G1, S and G1/S phases.     

Vulnerability Assessment of Water Resources Systems in the Eastern Nile Basin

Planning effective joint development programs in shared river basins is thought to become better when such programs are preceded by integrated studies. This paper aims to provide such a study through a situation analysis with regard to the vulnerability of water resources systems in the Eastern Nile Basin (ENB). The focus was on using internationally recognized indicators and indices that can provide an insight about the situation in the region in a concise and illustrative fashion. A framework for assessing vulnerability of water systems was outlined and applied to the region. Based on a careful survey, a list of 31 indicators used for vulnerability assessment were identified and categorized to separate hydro-physical indicators from other indicators of socio-economic or political nature. The identified indicators were evaluated for the three ENB countries and illustrated in radar diagrams. Interpretations were drawn describing the vulnerability situation in each country. The main findings are: (1) vulnerability of water resources is highest in Sudan, followed by Ethiopia and then Egypt; (2) while vulnerability in Egypt stems mainly from hydro-physical factors; in Sudan and Ethiopia it is directly related to poverty and underdevelopment; (3) Higher stresses on available water resources in Egypt are due to increases in total withdrawals; while in Sudan and Ethiopia it is mainly due to water mal-distribution and quality deterioration; (4) governance factors in the three countries hinder the proper management of the available water resources.