Publications by authors named "Mohammad Mansour"

5 Publications

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Compressional-Wave Effects in the Operation of a Quartz Crystal Microbalance in Liquids:Dependence on Overtone Order.

Sensors (Basel) 2020 Apr 29;20(9). Epub 2020 Apr 29.

Institute of Physical Chemistry, Clausthal University of Technology, Arnold-Sommerfeld-Str. 4, D-38678 Clausthal-Zellerfeld, Germany, (F.M.).

The operation of the quartz crystal microbalance (QCM) in liquids is plagued by small flexural admixtures to the thickness-shear deformation. The resonator surface moves not only in the transverse direction, but also along the surface normal, thereby emitting compressional waves into the liquid. Using a simple analytical model and laser Doppler vibrometry, we show that the flexural admixtures are stronger on the fundamental mode than on the overtones. The normal amplitude of motion amounts to about 1% of the transverse motion on the fundamental mode. This ratio drops by a factor of two on the overtones. A similar dependence on overtone order is observed in experiments, where the resonator is immersed in a liquid and faces an opposite planar wall, the distance of which varies. Standing compressional waves occur at certain distances. The amplitudes of these are smaller on the overtones than on the fundamental mode. The findings can be rationalized with the tensor form of the small-load approximation.
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http://dx.doi.org/10.3390/s20092535DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7249204PMC
April 2020

Knowledge and attitudes towards E-cigarette use in Lebanon and their associated factors.

BMC Public Health 2020 Feb 28;20(1):278. Epub 2020 Feb 28.

Epidemiology and Population Health Department, Faculty of Health Sciences, American University of Beirut, P.O.Box 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.

Background: Despite the misconceptions regarding E-cigarettes (ECs), only a few studies have been conducted in the Middle East that focused on this topic. This study assesses the knowledge of and attitudes towards ECs in Lebanon, determines how these two measures are associated, and identifies the variables that explain each of these measures.

Methods: A cross sectional study was conducted on a convenience sample of Lebanese pedestrians aged between 18 and 64 inclusive. A structured self-administered questionnaire comprising of knowledge and attitude scales, and questions on demographical, health and smoking characteristics was used.

Results: Scores for attitudes and knowledge of ECs were summed and dichotomized using a 75% cutoff, above which the participant was considered to have a positive attitude and good knowledge. Among the 352 participants (56.6% males, 43.3% females, mean age 30.3, 46.2% smokers), 63.3% exhibited a lower level of EC knowledge. More than 50% erroneously thought that ECs are not associated with lung and bladder cancer or impair lung and heart function. 65% falsely thought that it is harmless and not addictive. As for attitude, 43.3, 53.9, and 44.3% thought that it is socially acceptable, helps in smoking cessation, and is a good replacement for cigarettes and an enjoyable recreational device respectively. Our results revealed an inverse correlation between attitude and knowledge scores (Spearman's correlation = -.30, p < .001). Predictors of knowledge included health-related occupation (p = .010), regular exercise (p = .016), healthy diet (p = .026), EC use (p = .026), perception that ECs are not harmful (p = .001), and help in smoking cessation (p = .017). Predictors of attitude included EC use (p = .008), sex (p = .010), and knowledge that most ECs are addictive (p = .006), harmful (p = .014), and impair heart and lung function (p = .047).

Conclusions: Our study revealed a gap in EC knowledge, especially among participants who displayed a positive attitude towards ECs. Hence, measures should be undertaken to regulate its use by instituting more stringent laws and holding nationwide awareness campaigns.
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http://dx.doi.org/10.1186/s12889-020-8381-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7049178PMC
February 2020

Fatal Acute Liver Failure With Intravenous Amiodarone: A Case Report and Literature Review.

Gastroenterology Res 2018 Feb 23;11(1):62-63. Epub 2018 Feb 23.

Interfaith Medical Center, 1545 Atlantic Ave, Brooklyn, NY 11213, USA.

Amiodarone is a drug which frequently causes elevated transaminases. However, acute liver failure has been rarely reported. Here, we present a case of fatal acute liver failure following the administration of intravenous amiodarone. It is important to be aware of this rare but potentially fatal complication of intravenous amiodarone so that it can be withdrawn immediately at the first sign of hepatic impairment.
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http://dx.doi.org/10.14740/gr911wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5827905PMC
February 2018

Frequency of central nervous system tumors in delta region, Egypt.

Indian J Pathol Microbiol 2011 Apr-Jun;54(2):299-306

Department of Pathology, Mansoura University, Mansoura, Egypt.

Unlabelled: INTRODUCTION AND AIM OF WORK: Central nervous system (CNS) tumors represent a major public health problem, and their epidemiological data in Egypt have been rather incomplete except for some regional reports. There are no available frequency-based data on CNS tumors in our locality. The objective of this study was to estimate the frequency of CNS tumors in east delta region, Egypt.

Materials And Methods: The data were collected during the 8-year period from January 1999 to December 2007 from Pathology Department, Mansoura University, and other referred pathology labs. Examination of HandE stained sections from retrieved paraffin blocks were done in all cases for histopathologic categorization of C.N.S. tumors. Immunohistochemical studies were applied to confirm final histopathologic diagnosis in problematic cases.

Results: Intracranial tumors represented 86.7% of cases in comparison to only 13.3% for spinal tumors. Gliomas were the CNS tumors of the highest frequency (35.2%), followed by meningioma (25.6%), pituitary adenoma (11.6%) and nerve sheath tumors (6.6%). 10.25% of tumors were of children <15 years.

Conclusion: This study provides the largest series of the relative frequency of CNS tumors in Delta region in Egypt till now and may help to give insight into the epidemiology of CNS tumors in our locality.
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http://dx.doi.org/10.4103/0377-4929.81607DOI Listing
August 2011

Gastrointestinal malformations in two infants born to women with hyperthyroidism untreated in the first trimester.

Am J Perinatol 2003 Feb;20(2):59-62

Obstetrics and Gynecology, The American University of Beirut Medical Center, New York, New York 10022, USA.

We report two infants with gastrointestinal anomalies: one with esophageal atresia and tracheo-esophageal fistula and the other with biliary tree atresia, born to hyperthyroid women diagnosed and treated with methimazole after 14 weeks' gestation. Euthyroidism was documented in both infants. These cases raise the issue of whether untreated hyperthyroidism and not methimazole intake is the teratogen.
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http://dx.doi.org/10.1055/s-2003-38320DOI Listing
February 2003