Smoking among Saudi university students: consumption patterns and risk factors

Tobacco use is increasing among young people, especially in Gulf nations such as Saudi Arabia. The objectives of this study were to estimate the prevalence and behavioural patterns of tobacco use among undergraduate students at King Saud University, Riyadh, Saudi Arabia during the academic year 2008/09 and investigate factors that influenced their tobacco use. A cross-sectional study was done of a representative sample [n = 6793] of the undergraduate student population using a modified version of the global youth tobacco survey questionnaire. The prevalence of smoking was 14.5% among students, 22.2% and 2.2% among fathers and mothers and 43.1% and 14.8% for male and female siblings; 15.0% reported all or most of theirfriends smoked. The most important independent predictors of smoking were: friends' smoking [some: OR - 6.7 and all: OR - 54.9], sister's smoking [OR - 2.2], mother's smoking [OR = 2.1], single status [OR -1.7] and age [OR -1.18]

Biosorption of uranium in a continuous flow packed bed column using Cystoseira indica biomass

Uranium [2] biosorption from aqueous solution by Cystoseira indica biomass was studied in a packed bed column. The uptake capacity of uranium was investigated by natural and different pretreated biomasses. Results showed 0.1 M CaCl[2] solution at pH=4, used as pretreatment, increased the uptake capacity more than 30% [371.39 mg/g]. Cations concentration measurement in the effluent solution, Fourier transform infrared spectroscopy and X-ray fluorescence analyses on biosorbents proved that ion exchange is the main biosorption mechanism. The elution efficiency for uranium desorption was determined for various chemical agents in a batch system. Among these eluants, 0.1 M HCl exhibited elution efficiency greater than 78%. Also, biomass regeneration by 0.1 M HCl was studied in a continuous system. The obtained results confirmed that reusability of this biomass is conceivable. Thus, Cystoseira indica can be used in the packed bed column as a potential biosorbent for treatment of uranium polluted aqueous solutions

Accuracy of gray-scale and color doppler sonography in diagnosis of hepatic hemangioma, hepatocellular carcinoma and liver metastasis

Distinguishing cavernous hemangioma from malignant neoplasms represents a diagnostic challenge. Knowledge of the entire spectrum of gray-scale ultrasonography [US] and color Doppler appearances of these tumors is important. The objective of this study was to determine the diagnostic accuracy of gray-scale US and color Doppler appearances of liver tumors. 88 patients with 93 focal hepatic lesions were prospectively studied with gray-scale and color Doppler US. The final diagnoses of the liver lesions as confirmed by pathology or 99mTc-red blood cell scintigraphy were 41 hemangiomas, 15 hepatocellular carcinomas [HCCs] and 37 metastases. 87.8% of hemangiomas and 66.7% of HCCs were hyperechoic, while 54.1% of metastases were hypoechoic. In lesions < 3 cm in diameter, the sensitivity and specificity of the hyperechoic pattern for differentiation of hemangioma from metastasis and HCC were 94.1% and 80.0%, respectively. They were higher than the lesions with a diameter ?3 cm [83.3% and 45.9%, respectively, both P=0.001]. Posterior acoustic enhancement was seen in 78% of hemangiomas [P<0.001], as compared to 24.4% in metastases and 13.3% in HCCs. 10 hemangiomas had an echogenic rim. The peripheral hypoechoic rim, named as the target sign, was seen in 37.8% of metastases, 26.7% of HCCs and 2.4% of hemangiomas [P<0.001]. Most hemangiomas [85.4%] showed no lesional blood flow, while most HCCs [80%] had both intraand peri-lesional vascularity [P<0.001]. There was intratumoral blood flow in 86.7% of HCCs. Lesional flow, whether intratumoral or peritumoral or both, was seen in all 14 patients with HCC while absence of the lesional flow was not noted in any of the HCCs. Most hemangiomas had no detectable blood flow in color Doppler US. Almost all HCCs had intra- and/or peri-tumoral vascularity in color Doppler sonography, so the probability of hepatocellular carcinoma is low in a hepatic mass without intra- or peri-lesional vascular blood flow. So these findings together with morphological criteria may help narrow down the differential diagnosis in certain clinical conditions