Tobacco enhances bacterial-induced periodontal bone loss in mice.

Background: Tobacco smoking is the leading environmental risk factor for periodontal diseases. Delineation of the mechanisms underlying tobacco-induced or exacerbated periodontitis is hampered by the lack of an appropriate and reliable animal model. Hypothesis: We hypothesized that Porphyromonas-gingivalis-infected, cigarette smoke-exposed mice would represent reproducible models of acute (ligature model) and chronic (oral gavage model) tobacco-enhanced periodontitis that reflect multiple aspects of the disease noted in human smokers. Methods: In a chronic oral gavage disease model, Balb/c mice (6-8 weeks, 4 groups of n = 6 per group) were exposed to smoke produced by a Teague-10 smoking machine from 1R6F research cigarettes (20 cigarettes per day over 3 hours; mean carbon monoxide (CO), 150 ppm; mean particulate exposure, 4.9 mg/m3) or exposed to ambient air, over 68 days. The mice were repeatedly orally inoculated with Streptococcus gordonii and Porphyromonas gingivalis or sham inoculated. At euthanasia, the IgM and IgG response to infection; systemic inflammatory mediators; specific local gingival inflammatory indices (IL-1β, MMP-8, MMP-9, CD14and CD45); as well as alveolar bone loss were assessed. In an acute ligature-induced disease model, Balb/c mice (6-8 weeks, 4 groups of n = 7 per group) were exposed to smoke (20 cigarettes per day over 3 hours; mean CO, 200 ppm; mean particulate exposure, 9.8 mg/m3) or exposed to ambient air, over 14 days. The mice vii were repeatedly orally inoculated with P. gingivalis or sham inoculated. At euthanasia, IgM and IgG response to infection, alveolar bone loss was assessed. Plans to assess local and systemic inflammatory indices were curtailed by the Covid-19 outbreak. Results: In a chronic model of periodontitis, tobacco smoke exposure enhanced bacteria-induced bone loss (p\u3c 0.01). Systemic innate immune suppression was also apparent, as indicated by reduced levels of systemic CCL2, CXCL1, MIP-1b,GM-CSF,IL-13, and IL-10 (all p\u3c 0.05), while local expression of MMP-8 was augmented in infected mice (p\u3c 0.05). However, tobacco smoke exposure did not influence murine mass, IgM or IgG ,or the mRNA signal of inflammatory mediator’s in murine gingiva. In the acute model of periodontitis, tobacco smoke exposure, again, enhanced bacteria-induced bone loss (p\u3c 0.01). Body mass differentials were also influenced by smoke exposure (

Effect of cfrp strips bonding location on flexural capacity and ductility of reinforced concrete beams

[abstract not available]https://fount.aucegypt.edu/faculty_book_chapters/1356/thumbnail.jp

Chemosensitizing effect of maitake mushroom extract on carmustine cytotoxicity in human bladder cancer cells

Background: Despite several therapeutic options available for bladder cancer, the outcomes are less satisfactory.  To find a more effective modality, we were interested in the bioactive mushroom extract, PDF, which has been shown to sensitize certain anticancer drugs.  Accordingly, we investigated if cytotoxic effects of several anticancer drugs used on bladder cancer patients could be enhanced with PDF in vitro.Methods: Human bladder cancer T24 cells were treated with four anticancer drugs, carmustine (BCNU), 5-fluorouracil (5FU), cisplatin (CPL), and doxorubicin (DOX) alone, their combinations, or in combination with PDF, and cell viability was determined.  To explore the anticancer mechanism, the status of glyoxalase I (Gly-I), an enzyme involved in the drug resistance of cancer cells, and oxidative stress that can cause severe cellular injury/damage was also assessed.Results: BCNU and 5FU alone resulted in a >50% reduction in cell viability but CPL and DOX had no such effects.  Only a combination of BCNU and PDF led to a drastic (~90%) cell viability reduction, accompanied by inactivation of Gly-I and an increase in oxidative stress.  However, any combinations of other drugs and PDF had little effects on cell viability, Gly-I activity, or severity of oxidative stress.Conclusions: This study shows that anticancer activity of BCNU is significantly potentiated with PDF in T24 cells.  This is rather attributed to inactivated Gly-I and increased oxidative stress.  Therefore, PDF appears to have a chemosensitizing effect capable of enhancing BCNU cytotoxicity, which may offer an alternative, improved therapeutic option for bladder cancer

On the Fracture of Brittle and Quasi-Brittle Materials Subject to Uniaxial Compression

Fracture of brittle and quasi-brittle solids subject to uniaxial compression has been a challenging topic for decades with little dispersed progress. No well-defined solution for this problem was developed until the day this thesis was finalized. In this thesis, the differences between fracture in compression and in tension are explained making the later a straightforward problem to tackle and form a well-defined commonly-used solution. Exploratory experiments were conducted to gather experimental measurements required for realistic numerical simulation and to confirm that a big void in a compressed brittle/quasi-brittle solid will act as a stress raiser and trigger crack propagation. A 2D numerical model was developed using the material properties collected from the experiments. For a discontinuity to have that effect in a uniaxially compressed brittle solid it needs to have a width and height; a one-dimensional hairline crack is ineffective. The effect of varying initial voids geometry was studied in the first parametric study presented in this thesis. The width (direct relationship), height (inverse relationship), size (direct relationship) and shape of the void are shown to be important in triggering crack propagation, but not the width-to-height ratio. Vertical elliptical voids were found to be less critical than all the other voids studied. In the second parametric study, the effect of a secondary void neighbouring a bigger main void is studied, with both voids being circular to resemble air bubbles. Agreement between the modelled crack paths and cracks observed in the experiments was found, explaining why some cracks emanate from the sides of bigger voids. The findings presented in this study are eye-opening to the reason why research progress in the field has been very slow compared to other topics of Fracture Mechanics

Wireless control of reconfigurable antenna arrays

We developed a system that allows a user to wirelessly control reconfigurable antenna arrays using software. The array consists of four coplanar folded slot antenna elements and its different states can be activated or deactivated remotely on-demand to alter the entire array’s resonant frequency. The array alters its operating frequency by changing the status of eight couples of p-i-n diodes simultaneously (four diodes per antenna element). The control system is described and the performance of the reconfigurable array was measured and discussed

Self-Adaptive Flexible Antenna Array System , Mason Cover

Abstract-In the last decade self-adaptive and reconfigurable antenna arrays gained a lot of interest, and the concept of converting a simple antenna element or antenna array into a smart system was one of the research growing areas

Scanning characteristics of a self-adapting phased-array antenna on a wedge-shaped conformal surface

Abstract—The scanning characteristics of a linear five-element antenna array on a wedge-shaped conformal surface is inves-tigated in this work. In particular, the half-power beamwidth (HPBW) of a self-adapting array is studied for various changing conformal surfaces. A general array factor expression is derived and used to compute the HPBW. From these results, the self-adapting limitations of the array are outlined. Finally, analytical computations are validated with measurements. Index Terms—Microstrip Array and Phased Array Antennas I