PWM Control Techniques for Single-Phase Multilevel Inverter Based Controlled DC Cells

Sayed, Mahmoud A.,Ahmed, Mahrous,Elsheikh, Maha G.,Orabi, Mohamed The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper presents a single-phase five-level inverter controlled by two novel pulse width modulation (PWM) switching techniques. The proposed PWM techniques are designed based on minimum switching power loss and minimum total harmonic distortion (THD). In a single-phase five-level inverter employing six switches, the first proposed PWM technique requires four switches to operate at switching frequency and two other switches to operate at line frequency. The second proposed PWM technique requires only two switches to operate at switching frequency and the rest of the switches to operate at line frequency. Compared with conventional PWM techniques for single-phase five-level inverters, the proposed PWM techniques offer high efficiency and low harmonic components in the output voltage. The validity of the proposed PWM switching techniques in controlling single-phase five-level inverters to regulate load voltage is verified experimentally using a 100 V, 500 W laboratory prototype controlled by dspace 1103.

In-vitro release and in-vivo performance of tolmetin from different topical gel formulations

Sayed Hassan Auda,Saleh Abd El-Rasoul,Mahmoud Mohamed Ahmed,Shaaban Khalaf Osman,Mahmoud El-Badry 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.3

This study was designed to evaluate the suitability of Pluronic F-127, different grades of Carbopol and cellulosic polymers as gel bases containing tolmetin, a nonsteroidal anti-inflammatory drug. In vitro release characteristics, effect of enhancers, viscosity and the mechanism of drug release for different gel bases was studied as well as the anti-inflammatory activity were evaluated. The results showed that the HPMC gel has the superior percent of drug release than the others. The percent released of drug from Carbopol and the Pluronic F-127 gels is concentration defendants. It was found that the drug release from the tested gel bases obeyed the diffusion mechanism. The use of propylene glycol and urea in different concentrations (3.0, 5.0 and 10 % w/v) had enhanced the percent of drug release significantly (p<0.05). The anti-inflammatory activity of the drug in Carbopol gel formulation showed excellent anti-inflammatory activity. These finding highlight the potential local application of tolmetin gel as topical anti-inflammatory medication.

Improving the physicochemical and antioxidative properties of fermented goat milk using carob molasses and some probiotic strains

Mahmoud Ibrahim El-Sayed,Esmat Aly,Amany Mohammed El-Deeb 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.3

Fermented goat milk samples, processed by adding 0, 2, and 4% carob molasses, and Bifidobacterium bifidum DSMZ or Lactobacillus helveticus CH5, were evaluated for their physicochemical, antioxidative, and sensory properties along with probiotic viability during storage. pH and viscosity gradually decreased over the storage period whereas their values increased with the increased amount of carob molasses. Bifidobacterium bifidum DSMZ or Lactobacillus helveticus CH5 kept higher viable numbers. Lactobacillus helveticus CH5 strain recorded higher viability. Increasing the added amount of carob molasses increased the total phenolic content, which in turn is reflected in the increase in antioxidant activity. Adding carob molasses participated in the partial masking of the goaty flavor and had no significant effect on the product’s acceptability, which was strongly influenced by the progress of cold storage. Therefore, fermented goat milk described by its enhanced physicochemical and antioxidative properties could be obtained by adding carob molasses and probiotics.

Expression of Cyclooxygenase-2 (COX-2) in Colorectal Adenocarcinoma: an Immunohistochemical and Histopathological Study

Mahmoud, Abla Sayed,Umair, Ayesha,Azzeghaiby, Saleh Nasser,Alqahtani, Fahad Hussain,Hanouneh, Salah,Tarakji, Bassel Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Background: The aim of this study was to evaluate cyclooxygenase-2 (COX-2) immunoreactivity in colorectal adenocarcinomas and to find correlations with different pathological features. Materials and Methods: This study included 35 cases of colorectal carcinoma foir which surgical colectomy specimens were collected. Immunohistochemical staining of COX-2 (cyclooxygenase-2) is done by using the Streptavidin-biotin technique. Results: This work reveals that COX-2 is positive in most cases of colorectal carcinoma and negative in normal colon tissue with statistically non significant relations between COX-2 immunostaining and different pathological features. Conclusions: Our data suggest over expression of COX-2 protein in colorectal carcinoma in contrast to normal mucosa, with a possible role in cell proliferation in carcinogenesis.

PWM Control Techniques for Single-Phase Multilevel Inverter Based Controlled DC Cells

Mahmoud A. Sayed,Mahrous Ahmed,Maha G. Elsheikh,Mohamed Orabi 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

This paper presents a single-phase five-level inverter controlled by two novel pulse width modulation (PWM) switching techniques. The proposed PWM techniques are designed based on minimum switching power loss and minimum total harmonic distortion (THD). In a single-phase five-level inverter employing six switches, the first proposed PWM technique requires four switches to operate at switching frequency and two other switches to operate at line frequency. The second proposed PWM technique requires only two switches to operate at switching frequency and the rest of the switches to operate at line frequency. Compared with conventional PWM techniques for single-phase five-level inverters, the proposed PWM techniques offer high efficiency and low harmonic components in the output voltage. The validity of the proposed PWM switching techniques in controlling single-phase five-level inverters to regulate load voltage is verified experimentally using a 100 V, 500 W laboratory prototype controlled by dspace 1103.

The impact of caudally administrated tramadol on immune response and analgesic efficacy for pediatric patients: a comparative randomized clinical trial

( Jehan Ahmed Sayed ),( Sayed Kaoud Abd Elshafy ),( Emad Zareif Kamel ),( Mohamed Amir Fathy Riad ),( Amal Ahmed Mahmoud ),( Ghada Shalaby Khalaf ) 대한통증학회 2018 The Korean Journal of Pain Vol.31 No.3

Background: Immune responses appear to be affected by anesthetics and analgesics. We investigated the effects of caudal tramadol on the postoperative immune response and pain management in pediatric patients. Methods: Sixty ASA-I pediatric patients aged 3-10 years undergoing lower abdominal surgery. Patients were randomly assigned either to a caudal bupivacaine (0.25%) group (group B), or a group that received caudal tramadol (1 mg/kg) added to the bupivacaine (0.25%) (group T). Both were diluted in a 0.9% NaCl solution to a total volume of 1ml/ kg. The systemic immune response was measured by collecting blood samples preoperatively, at the end of anesthesia, and at 24 and 72 hours postoperatively, and studied for interleukin IL-6, C-reactive proteins (CRP) cortisol levels, and leucocytes with its differential count. Postoperative pain was assessed along with sedation scales. Results: Postoperative production of IL-6 was significantly higher in group B at the end of anesthesia, than at the 24th hour, and at the 72nd hour in group B and group T, respectively. The immune response showed leukocytosis with increased percentages of neutrophil and monocytes, and a decreased lymphocyte response rate within both groups with no significant differences between the groups. Cortisol and CRP were significantly higher in group B. Conclusions: Adding tramadol to a caudal bupivacaine block can attenuate the pro-inflammatory cytokine response, Cortisol, and CRP in children undergoing lower abdominal surgery. (Korean J Pain 2018; 31: 206-14)

Molecular mechanism of empagliflozin cardioprotection in 5-fluorouracil (5-FU)-induced cardiotoxicity via modulation of SGLT2 and TNFα/TLR/NF-κB signaling pathway in rats

Refaie Marwa Monier Mahmoud,Shehata Sayed,El-Hussieny Maram,Fawzy Michael Atef,Ahmed Nagwa Zenhom Mustafa,Marey Heba,Hishmat Asmaa Mohammed,Alkully Turki,Rahman Eman Shaaban Mahmoud Abd El 한국독성학회 2024 Toxicological Research Vol.40 No.1

One of the commoly used chemotherapeutic agents is 5-Fluorouracil (5-FU). Unfortunately, the clinical administration of 5-FU is complicated with serious cardiotoxic effects and the safe use becomes an urgent task in cardio-oncology. Till now, there are no studies discussed the role of empagliflozin (EMP) against 5-FU cardiotoxicity. Thus, we investigated this effect and the involved mechanisms in 5-FU induced heart injury. Forty male rats of Wistar albino species were used and divided randomly into four groups. Group I is the control group, group II is EMP given group, group III is 5-FU cardiotoxic group and group IV is 5-FU plus EMP group. 5-FU (150 mg/kg) was administered as a single intraperitoneal (i.p.) dose on 1st day to induce cardiotoxicity with or without EMP (30 mg/kg/d) orally for 5 days. The dose of 5-FU is relevant to the human toxic dose. Our data showed that 5-FU given group caused cardiotoxicity with significant increase of serum cardiac enzymes, toll like receptors, enhancement of nuclear factor kappa B (NF-κB), interleukin1β (IL1β), IL6, myeloid-differentiation-factor 88 (MYD88), heart weight, malondialdehyde (MDA), tumor-necrosis-factor-alpha (TNFα), sodium glucose co-transporter 2 (SGLT2), P53 and caspase3 expression with clear histopathological features of cardiotoxicity. Moreover, there is a significant decrease in reduced glutathione (GSH) and total antioxidant capacity (TAC). Interestingly, co-administration of EMP could ameliorate 5-FU induced biochemical and histopathological changes. This effect may be due to modulation of SGLT2, decreasing inflammation, oxidative stress and apoptosis with downregulation of an essential inflammatory cascade that mediates 5-FU cardiotoxicity; TNFα/TLR/NF-κB.

Synthesis of New 4-Oxo-2-Thioxo-1,2,3,4-Tetrahydropyrimidine Derivatives with an Incorporated Thiazolidinone Moiety ...

Mahmoud Mohamed Bahgat,Amany Sayed Maghraby,Mogeda Emam Heiba,Andreas Ruppel,Omar Abd-elfattah Mohamed Fathalla 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.9

5-Substituted 4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine were synthesized by interaction of 4- oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-sulfonylhydrazide with some aldehydes to give the corresponding Schiff-bases, which after cyclization gave corresponding thiazolidinones. For some of the thiazolidinones, Mannich bases reaction was carried out. All the derivatives were tested for their possible inhibitory effect on Schistosoma mansoni cercarial elastase (CE). Only, N'-(4-methylbenzyledine)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-sulfonylhydrazide was found to have potent inhibitory effect on the CE activity with IC50 = 264 µM. Upon its use as a paint for mice tails before infection with S. mansoni cercariae, the compound formulated in jojoba oil caused a significant reduction (93%; P-value = 0.0002) in the worm burden. IgG & IgM in mice sera were measured by using several S. mansoni antigens by ELISA. Sera from treated infected mice (TIM) 2, 4, and 6 weeks (W) post infection (PI) showed 1.2 folds lower, 1.2 folds higher, 1.7 folds lower IgM reactivity against soluble cercarial antigenic preparation (CAP), respectively, when compared with sera collected from infected untreated mice (IUM). Sera from TIM 2, 4, and 6WPI showed 1.3, 1.6, and 1.7 folds higher IgG reactivity, respectively against CAP than the IgG reactivity from IUM. Sera from TIM 2, 4 and 6WPI showed 1.5, 1.2 folds lower and 1.4 folds higher IgM reactivity, respectively against soluble worm antigenic preparation (SWAP) when compared with sera collected from IUM. Sera from TIM 2, 4, and 6WPI showed 1.4, 1 folds lower and 1 fold higher IgG reactivity, respectivley to SWAP when compared with sera from IUM. Sera from TIM 2, 4, and 6WPI had generaly lower IgM and IgG reactivities against soluble egg antigen (SEA) when compared with sera from IUM.

Osteoblast-Based Therapy—A New Approach for Bone Repair in Osteoporosis: Pre-Clinical Setting

Mahmoud Nadia Samy,Mohamed Mohamed Ragaa,Ali Mohamed Ahmed Mohamed,Aglan Hadeer Ahmed,Amr Khalda Sayed,Ahmed Hanaa Hamdy 한국조직공학과 재생의학회 2020 조직공학과 재생의학 Vol.17 No.3

BACKGROUND: Osteoporosis is a metabolic bone disease characterized by low bone density resulting in increased fracture susceptibility. This research was constructed to uncover the potential therapeutic application of osteoblasts transplantation, generated upon culturing male rat bone marrow-derived mesenchymal stem cells (BM-MSCs) in osteogenic medium (OM), OM containing gold (Au-NPs) or gold/hydroxyapatite (Au/HA-NPs) nanoparticles, in ovariectomized rats to counteract osteoporosis. METHODS: Forty rats were randomized into: (1) negative control, (2) osteoporotic rats, whereas groups (3), (4) and (5) constituted osteoporotic rats treated with osteoblasts yielded from culturing BM-MSCs in OM, OM plus Au-NPs or Au/ HA-NPs, respectively. After 3 months, osterix (OSX), bone alkaline phosphatase (BALP), sclerostin (SOST) and bone sialoprotein (BSP) serum levels were assessed. In addition, gene expression levels of cathepsin K, receptor activator of nuclear factor-jb ligand (RANKL), osteoprotegerin (OPG) and RANKL/OPG ratio were evaluated using real-time PCR. Moreover, histological investigation of femur bone tissues in different groups was performed. The homing of implanted osteoblasts to the osteoporotic femur bone of rats was documented by Sex determining region Y gene detection in bone tissue. RESULTS: Our results indicated that osteoblasts infusion significantly blunted serum BALP, BSP and SOST levels, while significantly elevated OSX level. Also, they brought about significant down-regulation in gene expression levels of cathepsin K, RANKL and RANKL/OPG ratio versus untreated osteoporotic rats. Additionally, osteoblasts nidation could restore bone histoarchitecture. CONCLUSION: These findings offer scientific evidence that transplanting osteoblasts in osteoporotic rats regains the homeostasis of the bone remodeling cycle, thus providing a promising treatment strategy for primary osteoporosis.

Antimicrobial Activity of New 4,6-Disubstituted Pyrimidine, Pyrazoline, and Pyran Derivatives

Mahmoud M. M. Ramiz,Wael A. El-Sayed,Asmaa I. El-Tantawy,Adel A. H. Abdel-Rahman 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

A number of new 2,6-didisubstituted pyrimidine, pyrazoline, and pyran derivatives were synthesized starting from their chalcone derivative. The synthesized compounds displayed different degrees of antimicrobial activity against Bscillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes).