Influence of limestone filler and of the size of the aggregates on DEF

This experimental study aims to determine the effect of limestone filler on concrete expansion due to delayed ettringite formation (DEF). Different mortars made with different sizes and percentages of limestone filler and Portland cement CEM I 52.5N are conserved in water. The expansion of the specimens is measured. Results show that DEF is not inhibited by limestone filler. The kinetics and the amplitude of the swelling depend on the size of the limestone filler. The volume fraction of aggregates changes only the kinetics: the relation between swelling and water uptake depends only on the size of the aggregates.Comment: 16 pages, 9 figures, 4 table

Asymmetric Cascaded Multilevel Inverter with Unequal Dc Sources using SPWM and MSVPWM Topologies

This paper introduces the modeling design and simulation of seven and thirteen levels cascaded asymmetric multilevel inverter (MLI) with reduced number of switches.  MLI is the most efficient energy converters which are essentially appropriated for high power applications with decrease total harmonics distortion (THD). MLI doesn't only get high power in the output but it is also utilized in renewable energy resources such as fuel cells, wind and photovoltaic cells. This paper principally focuses on a hybrid cascaded MLI with two and three unequal dc supplies which decreases the number of semiconductor power switches. Sinusoidal PWM (SPWM) and modified space vector PWM (MSVPWM) techniques are used to improve an ac output with reduced THD. The gating pulses for seven and thirteen level hybrid cascaded converter using SPWM and MSVPWM techniques are introduced. The results of these proposed modulation strategies reduce the percentage magnitude of THD. The performance of the proposed SPWM and MSVPWM topologies are verified using seven and thirteen levels cascaded asymmetric MLI via simulink/matlab. Keywords: Sinusoidal Pulse Width Modulation (SPWM), Modified Space Vector Pulse Width Modulation (MSVPWM), Multilevel Inverter (MLI), Total Harmonics Distortion (THD)

Histological Evaluation of A unilateral Critical-Sized Mandibular Defect Reconstruction using human dental pulp stem cells by Light Microscope and Real-Time Quantitative PCR

Objective: To evaluate the osteogenic differentiation potential of human dental pulp stem cells (DPSCs) isolated from the dental pulp of third molar teeth in vitro cultures, and to evaluate the bone regenerative capacity of human dental pulp stem cells (DPSCs) when transplanted into a unilateral critical-sized bone defect in the mandibular bone in vivo after receiving a hydroxyapatite matrix and polylactic-polyglycolic acid (HA/PLGA) scaffold. Material and methods: A total of 18 mandibular defects were made, and three groups (each n = 6) were created. The first group: the transplanted DPSCs implanted in the critical-sized bone defect after receiving (HA/PLGA) scaffold. The second group received only (HA/PLGA) scaffold. The third group, which served as the control, had a critical-sized defect left empty. After characterization, Von Kossa [VK] and Alizarin red staining were employed to identify differentiated osteoblasts at the 14th and 21st days, and histological analyses, as well as polymerase chain reactions (PCR), were also used. Results: It showed that DPSCs had high proliferation potential and typical fibroblastic shape. Additionally, osteogenic differentiation of DPSCs was validated by morphological alterations, histological examination, and the expression of lineage-specific genes confirmed osteogenic differentiation of DPSCs. Conclusion: High proliferation potential and the capacity to differentiate into osteoblasts are two characteristics of DPSCs taken from impacted third molars

The significance of Epstein Barr Virus (EBV) & DNA Topoisomerase II alpha (DNA-Topo II alpha) immunoreactivity in normal oral mucosa, Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC)

<p>Abstract</p> <p>Background</p> <p>Head and neck cancer including oral cancer is considered to develop by accumulated genetic alterations and the major pathway is cancerization from lesions such as intraepithelial dysplasia in oral leukoplakia and erythroplakia. The relationship of proliferation markers with the grading of dysplasia is uncertain. The involvement of EBV in oral carcinogenesis is not fully understood.</p> <p>Aim</p> <p>The present study was designed to investigate the role of EBV and DNA Topoisomerase II∝ (DNA-Topo II∝) during oral carcinogenesis and to examine the prognostic significance of these protein expressions in OSCCs.</p> <p>Methods</p> <p>Using specific antibodies for EBV and DNA-Topo II∝, we examined protein expressions in archival lesion tissues from 16 patients with oral epithelial dysplasia, 22 oral squamous cell carcinoma and 20 normal oral mucosa by immunohistochemistry. Clinical information was obtained through the computerized retrospective database from the tumor registry.</p> <p>Results</p> <p>DNA-Topo II∝ was expressed in all examined specimens. Analysis of Variance ANOVA revealed highly significant difference (P < 0.01) in young aged labial tissues and significant (P ≤ 0.05) in gingival and not significant (P > 0.05) in inferior surface of tongue and in hard palatal tissues. Significant differences were observed between OEDs and NSE (P < 0.001) and SCCs and controls (P < 0.001), also, significant differences could be observed between SCCs and OEDs. DNA-Topo II∝ expression was significantly higher in tumors of low differentiation versus tumors of moderate and high differentiation (P < 0.001), DNA-Topo II∝ expression was correlated with age, tumor size, tumor stage, node metastasis and tumor differentiation, but not with gender and tumor site. None of normal squamous epithelium (NSE) expressed EBV. Heterogenous reactivity for EBV was observed through the series of dysplasia and squamous cell carcinoma. Its expression increased progressively with lymph node metastasis and low tumor differentiation, but no significant association could be observed with other clinicopathological parameters. EBV protein expression was increased with elevated Topo II-∝ LI in OEDs and OSCCs. A tendency to positive correlation between EBV and Topo II∝ expression was observed in OEDs but not in OSCCs.</p> <p>Conclusion</p> <p>EBV and DNA Topo II-αLI expression are possible indicators in oral carcinogenesis and may be valuable diagnostic and prognostic indices in oral carcinoma.</p

Improved Survival With Higher-risk Donor Grafts in Liver Transplant With Acute-on-chronic Liver Failure

Use of higher-risk grafts in liver transplantation for patients with acute-on-chronic liver failure (ACLF) has been associated with poor outcomes. This study analyzes trends in liver transplantation outcomes for ACLF over time based on the donor risk index (DRI). Methods: Using the Organ Procurement and Transplantation Network and the United Network for Organ Sharing registry, 17 300 ACLF patients who underwent liver transplantation between 2002 and 2019 were evaluated. Based on DRI, adjusted hazard ratios for 1-y patient death were analyzed in 3 eras: Era 1 (2002-2007, n = 4032), Era 2 (2008-2013, n = 6130), and Era 3 (2014-2019, n = 7138). DRI groups were defined by DRI2.0. Results: ACLF patients had significantly lower risks of patient death within 1 y in Era 2 (adjusted hazard ratio, 0.69; 95% confidence interval, 0.61-0.78; P \u3c 0.001) and Era 3 (adjusted hazard ratio, 0.48; 95% confidence interval, 0.42-0.55; P \u3c 0.001) than in Era 1. All DRI groups showed lower hazards in Era 3 than in Era 1. Improvement of posttransplant outcomes were found both in ACLF-1/2 and ACLF-3 patients. In ACLF-1/2, DRI 1.2 to 1.6 and \u3e2.0 had lower adjusted risk in Era 3 than in Era 1. In ACLF-3, DRI 1.2 to 2.0 had lower risk in Era 3. In the overall ACLF cohort, the 2 categories with DRI \u3e1.6 had significantly higher adjusted risks of 1-y patient death than DRI \u3c1.2. When analyzing hazards in each era, DRI \u3e 2.0 carried significantly higher adjusted risks in Eras 1 and 3\u27 whereas DRI 1.2 to 2.0 had similar adjusted risks throughout eras. Similar tendency was found in ACLF-1/2. In the non-ACLF cohort, steady improvement of posttransplant outcomes was obtained in all DRI categories. Similar results were obtained when only hepatitis C virus-uninfected ACLF patients were evaluated. Conclusions: In ACLF patients, posttransplant outcomes have significantly improved, and outcomes with higher-risk organs have improved in all ACLF grades. These results might encourage the use of higher-risk donors in ACLF patients and provide improved access to transplant

Homing and reparative effect of intra-articular injection of autologus mesenchymal stem cells in osteoarthritic animal model

<p>Abstract</p> <p>Background</p> <p>This work aimed to study the homing evidence and the reparative effect of mesenchymal stem cells (MSCs) in the healing process of induced osteoarthritis in experimental animal model (donkeys).</p> <p>Methods</p> <p>Twenty-seven donkeys were equally divided into 3 groups based on the observation period after induction of arthritis (3, 6 and 9 weeks) to achieve different degrees of osteoarthritis. Each group was subdivided into three subgroups of three animals each based on the follow-up period (1, 2 and 6 months) after treatment. The induction was done through intra-articular (IA) injection of 2 ml of Amphotericin-B in both carpal joints. MSCs were harvested in a separate procedure, labeled with green fluorescent protein (GFP) using monster GFP vector and suspended in hyaluronic acid for IA injection. Treatment approaches consisted of cell-treatment using MSCs suspended in 3 ml of hyaluronic acid (HA) for the right carpal joint; and using the same amount of (HA) but without MSCs for the left contralateral carpal joint to serve as a control. Animals were assessed clinically and radiologically before and after treatment. Synovial fluid was also evaluated. Histopathologically; articular cartilage structural changes, reduction of articular cartilage matrix staining, osteophyte formation, and subchondral bone plate thickening were graded. Data was summarized using median and percentile for scores of histopathologic grading. Comparison between groups was done using non-parametric Mann Whitney test.</p> <p>Results</p> <p>The reparative effect of MSCs was significant both clinically and radiologically in all treated groups (P < 0.05) compared to the control groups. Fluorescence microscopy of sections of the cell-treated joints of all animals indicated that the GFP-transduced injected cells have participated effectively in the reparative process of the damaged articular surface and have integrated within the existing articular cartilage. The cells were associated with the surface of the cartilage and, were also detected in the interior.</p> <p>Conclusions</p> <p>Homing was confirmed by the incorporation of injected GFP-labeled MSCs within the repaired newly formed cartilage. Significant recovery proves that the use of IA injection of autologous MSCs is a viable and a practical option for treating different degrees of osteoarthritis.</p

Knowledge about stroke among adults in Sharjah, United Arab Emirates

Background: In UAE, stroke is the second leading cause of disability after RTA, where annually 8,000 to 10,000 patients get a stroke. Our aim is to identify the knowledge levels of stroke among Sharjah’s adult citizens.Methods: Using self-administered questionnaires, in a cross-sectional design, a non-probability convenience sampling method was used to enrol subjects. Eligible subjects were above 18 years of age, comprehended Arabic or English, and are currently residing in Sharjah. The questionnaire was 17 questions structured in 5 sections which included: demographics, general knowledge, knowledge of signs and symptoms, risk factors, and appropriate response towards stroke. SPSS V.22 was used to analyse the data. Percentages, means, and ANOVA were used. A P-value less than 0.05 was considered to be statistically significant.Results: The study included 426 subjects, mean age was 35.1 years, 65.2% were females. 51.8% of the subjects claimed they know what stroke is, out of whom 24.3% provided incorrect descriptions. The mean knowledge level of signs and symptoms was 55.4%, and of risk factors was 40.6%. Visual disturbance was the least identified of the five signs and symptoms (38.0%). Female gender, African American race, and age above 60, were the least identified of the 8 risk factors (4.7%, 3.5%, 19.8% respectively). Better knowledge was associated with increased age and higher education. Conclusion: The majority of the sample showed an average to low level of knowledge. Such results indicate the importance of implementing more awareness programs that target younger age groups in the community

Improvements in liver transplant outcomes in patients with HCV/HIV coinfection after the introduction of direct-acting antiviral therapies

BACKGROUND: In recipients with HCV/HIV coinfection, the impact that the wider use of direct-acting antivirals (DAAs) has had on post-liver transplant (LT) outcomes has not been evaluated. We investigated the impact of DAAs introduction on post-LT outcome in patients with HCV/HIV coinfection. METHODS: Using Organ Procurement and Transplant Network/United Network for Organ Sharing data, we compared post-LT outcomes in patients with HCV and/or HIV pre- and post-DAAs introduction. We categorized these patients into two eras: pre-DAA (2008-2012 [pre-DAA era]) and post-DAA (2014-2019 [post-DAA era]). To study the impact of DAAs introduction, inverse probability of treatment weighting was used to adjust patient characteristics. RESULTS: A total of 17 215 LT recipients were eligible for this study (HCV/HIV [n = 160]; HIV mono-infection [n = 188]; HCV mono-infection [n = 16 867]). HCV/HIV coinfection and HCV mono-infection had a significantly lower hazard of 1- and 3-year graft loss post-DAA, compared pre-DAA (1-year: adjusted hazard ratio [aHR] 0.29, 95% confidence interval (CI) 0.16-0.53 in HIV/HCV, aHR 0.58, 95% CI 0.54-0.63, respectively; 3-year: aHR 0.30, 95% CI 0.14-0.61, aHR 0.64, 95% CI 0.58-0.70, respectively). The hazards of 1- and 3-year graft loss post-DAA in HIV mono-infection were comparable to those in pre-DAA. HCV/HIV coinfection had significantly lower patient mortality post-DAA, compared to pre-DAA (1-year: aHR 0.30, 95% CI 0.17-0.55; 3-year: aHR 0.31, 95% CI 0.15-0.63). CONCLUSIONS: Post-LT outcomes in patients with coinfection significantly improved and became comparable to those with HCV mono-infection after introducing DAA therapy. The introduction of DAAs supports the use of LT in the setting of HCV/HIV coinfection

Short recipient warm ischemia time improves outcomes in deceased donor liver transplantation

While adverse effects of prolonged recipient warm ischemia time (rWIT) in liver transplantation (LT) have been well investigated, few studies have focused on possible positive prognostic effects of short rWIT. We aim to investigate if shortening rWIT can further improve outcomes in donation after brain death liver transplant (DBD-LT). Primary DBD-LT between 2000 and 2019 were retrospectively reviewed. Patients were divided according to rWIT (≤30, 31-40, 41-50, and \u3e50 min). The requirement of intraoperative transfusion, early allograft dysfunction (EAD), and graft survival were compared between the rWIT groups. A total of 1,256 patients of DBD-LTs were eligible. rWIT was ≤30min in 203 patients (15.7%), 31-40min in 465 patients (37.3%), 41-50min in 353 patients (28.1%), and \u3e50min in 240 patients (19.1%). There were significant increasing trends of transfusion requirement (P \u3c 0.001) and increased estimated blood loss (EBL, P \u3c 0.001), and higher lactate level (P \u3c 0.001) with prolongation of rWIT. Multivariable logistic regression demonstrated the lowest risk of EAD in the WIT ≤30min group. After risk adjustment, patients with rWIT ≤30 min showed a significantly lower risk of graft loss at 1 and 5-years, compared to other groups. The positive prognostic impact of rWIT ≤30min was more prominent when cold ischemia time exceeded 6 h. In conclusion, shorter rWIT in DBD-LT provided significantly better post-transplant outcomes