Heterocyclic Synthesis with Nitriles: New Routes for Synthesis of Pyridazines, Pyridines and their Fused Derivtives

Negm, Abdalla-M.,Abdelrazek, Fathy-M.,Elnagdi, Mohamed-H.,Shaaban, Lina-H. The Pharmaceutical Society of Korea 1994 Archives of Pharmacal Research Vol.17 No.6

Phenylazocyanothioacetamide 1 reacts with malononitrile to afford the pyridinethione 4 which reacts with phenacylbromide to yield the pyridine-S-phenacyl derivative 6, 1 reacts with ethyl cyanoacetate to yield the pyridazine derivative, 8, and with phenacyl bromide to afford the N-phenacyl derivative 11, instead of the thiazole 10. Compound 11 afforded the pyrazolopyridine 13 on reaction with malononitrile while 10 was obtained on coupling of the thiazole 14 with diazotised aniline. Compound 10 reacts with malononitrile to afford the thizaolyl pyridazine 15. Compound 1 reacts with malononitrile dimer to afford the pyriodopyridazine derivative 17a. 1 reacts also with active methylene heterocycies to afford the pyrazolo and thiazolo-fused phridazines 20 and 23 respectively.

Outer membrane proteins of Salmonella Typhimurium as an adjuvant in rabies vaccine

Iman Ibrahim Negm,Yasser M. Ragab,Aly Fahmy Mohamed 대한백신학회 2021 Clinical and Experimental Vaccine Research Vol.10 No.2

Purpose: The objective of the present study was to evaluate the immune-enhancing potential of Salmonella Typhimurium outer membrane protein (OMP) and alum as adjuvants towards inactivated Vero cells rabies vaccine (FRV/K2). Materials and Methods: Six groups of female Sprague Dawley albino rats (10/group) were used in the evaluation of immunogenicity and safety of vaccines and adjuvants. Total immunoglobulin G secreted interferon-gamma (IFN-γ), and the percentage of proliferated CD4+ and CD8+ T cells were measured. Biochemical analysis and histopathological examination were used to test safety profiles. Results: OMP adjuvanted rabies vaccine (FRV/K2+OMP) (OMP combined locally prepared vaccine) induced significantly higher neutralizing antibodies on day 21 post-vaccination relative to free (FRV/K2) vaccine and alum adsorbed vaccine (FRV/K2+alum) (alum adsorbed locally prepared vaccine). (FRV/K2+OMP) induced a significantly higher level of IFN-γ on day 14 post-vaccination. CD8+ T cells were significantly higher post-vaccination with reference (RV), free (FRV/K2), and (FRV/K2+OMP) than (FRV/K2+alum). On the contrary, CD4+ T cells were significantly elevated post-vaccination with (FRV/K2+alum) at p<0.05. Biochemical analysis and histopathological examination revealed that OMP could be used safely as an adjuvant for the development of more effective rabies vaccines. Conclusion: Outer membrane proteins adjuvanted rabies vaccines would be beneficial to induce rapid neutralizing antibodies and essential cytokines.

Suggested Integrative Approach for Hand Abscess with Cupping Therapy: a case study

Hussein Emad Ahmed Fathy,Negm Shahira Hassan Ibrahim,Shaikh Tabish Ishaq,Saleh Ahmed Helmy,Hussein Emad Ahmed Fathy 대한약침학회 2023 Journal of pharmacopuncture Vol.26 No.1

A forty-three-year-old male patient was diagnosed with an acute abscess in the dorsum of the right hand. On the 5th day of conventional pharmacological therapy the patient was still suffering, and was referred to the Outpatient department (OPD) to evacuate and drain the abscess and treat the edema around the area with Hijama (wet cupping therapy, WCT). The hand abscess was successfully cured within a week using an integrative approach of wet cupping therapy together with conventional drug therapy.

Improving wing aeroelastic characteristics using periodic design

Badran, Hossam T.,Tawfik, Mohammad,Negm, Hani M. Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.4

Flutter is a dangerous phenomenon encountered in flexible structures subjected to aerodynamic forces. This includes aircraft, buildings and bridges. Flutter occurs as a result of interactions between aerodynamic, stiffness, and inertia forces on a structure. In an aircraft, as the speed of the flow increases, there may be a point at which the structural damping is insufficient to damp out the motion which is increasing due to aerodynamic energy being added to the structure. This vibration can cause structural failure, and therefore considering flutter characteristics is an essential part of designing an aircraft. Scientists and engineers studied flutter and developed theories and mathematical tools to analyze the phenomenon. Strip theory aerodynamics, beam structural models, unsteady lifting surface methods (e.g., Doublet-Lattice) and finite element models expanded analysis capabilities. Periodic Structures have been in the focus of research for their useful characteristics and ability to attenuate vibration in frequency bands called "stop-bands". A periodic structure consists of cells which differ in material or geometry. As vibration waves travel along the structure and face the cell boundaries, some waves pass and some are reflected back, which may cause destructive interference with the succeeding waves. This may reduce the vibration level of the structure, and hence improve its dynamic performance. In this paper, for the first time, we analyze the flutter characteristics of a wing with a periodic change in its sandwich construction. The new technique preserves the external geometry of the wing structure and depends on changing the material of the sandwich core. The periodic analysis and the vibration response characteristics of the model are investigated using a finite element model for the wing. Previous studies investigating the dynamic bending response of a periodic sandwich beam in the absence of flow have shown promising results.

Improving aeroelastic characteristics of helicopter rotor blades in hovering

Badran, Hossam T.,Tawfik, Mohammad,Negm, Hani M. Techno-Press 2021 Advances in aircraft and spacecraft science Vol.8 No.3

Flutter is a dangerous phenomenon encountered in flexible structures subjected to aerodynamic forces. This includes aircraft, helicopter blades, engine rotors, buildings and bridges. Flutter occurs as a result of interactions between aerodynamic, stiffness, and inertia forces on a structure. The conventional method for designing a rotor blade to be free from flutter instability throughout the helicopter's flight regime is to design the blade so that the aerodynamic center (AC), elastic axis (EA) and center of gravity (CG) are coincident and located at the quarter-chord. While this assures freedom from flutter, it adds constraints on rotor blade design which are not usually followed in fixed wing design. Periodic Structures have been in the focus of research for their useful characteristics and ability to attenuate vibration in frequency bands called "stop-bands". A periodic structure consists of cells which differ in material or geometry. As vibration waves travel along the structure and face the cell boundaries, some waves pass and some are reflected back, which may cause destructive interference with the succeeding waves. In this work, we analyze the flutter characteristics of helicopter blades with a periodic change in their sandwich material using a finite element structural model. Results shows great improvements in the flutter rotation speed of the rotating blade obtained by using periodic design and increasing the number of periodic cells.

Improving aeroelastic characteristics of helicopter rotor blades in hovering

Badran, Hossam T.,Tawfik, Mohammad,Negm, Hani M. Techno-Press 2021 Advances in aircraft and spacecraft science Vol.8 No.3

Flutter is a dangerous phenomenon encountered in flexible structures subjected to aerodynamic forces. This includes aircraft, helicopter blades, engine rotors, buildings and bridges. Flutter occurs as a result of interactions between aerodynamic, stiffness, and inertia forces on a structure. The conventional method for designing a rotor blade to be free from flutter instability throughout the helicopter's flight regime is to design the blade so that the aerodynamic center (AC), elastic axis (EA) and center of gravity (CG) are coincident and located at the quarter-chord. While this assures freedom from flutter, it adds constraints on rotor blade design which are not usually followed in fixed wing design. Periodic Structures have been in the focus of research for their useful characteristics and ability to attenuate vibration in frequency bands called "stop-bands". A periodic structure consists of cells which differ in material or geometry. As vibration waves travel along the structure and face the cell boundaries, some waves pass and some are reflected back, which may cause destructive interference with the succeeding waves. In this work, we analyze the flutter characteristics of helicopter blades with a periodic change in their sandwich material using a finite element structural model. Results shows great improvements in the flutter rotation speed of the rotating blade obtained by using periodic design and increasing the number of periodic cells.

Aerothermoacoustic Response of Shape Memory Alloy Hybrid Composite Panels

Ibrahim, H.H.,Tawfik, M.,Negm, H.M.,Yoo, H.H. AMERICAN INST OF AERONAUTICS AND ASTRONAUTICS 2009 Journal of aircraft Vol.46 No.5

NONLINEAR FLUTTER OF SHAPE MEMORY ALLOY HYBRID COMPOSITE PANELS SUBJECT TO THERMAL AND RANDOM ACOUSTIC LOADS

Hesham H. Ibrahim,Mohammad Tawfik,Hani M. Negm,Hong Hee Yoo 한국소음진동공학회 2008 한국소음진동공학회 국제학술대회논문집 Vol.2008 No.7

Improving aeroelastic characteristics of helicopter rotor blades in forward flight

Badran, Hossam T.,Tawfik, Mohammad,Negm, Hani M. Techno-Press 2019 Advances in aircraft and spacecraft science Vol.6 No.1

Flutter is a dangerous phenomenon encountered in flexible structures subjected to aerodynamic forces. This includes aircraft, helicopter blades, engine rotors, buildings and bridges. Flutter occurs as a result of interactions between aerodynamic, stiffness and inertia forces on a structure. The conventional method for designing a rotor blade to be free from flutter instability throughout the helicopter's flight regime is to design the blade so that the aerodynamic center (AC), elastic axis (EA) and center of gravity (CG) are coincident and located at the quarter-chord. While this assures freedom from flutter, it adds constraints on rotor blade design which are not usually followed in fixed wing design. Periodic Structures have been in the focus of research for their useful characteristics and ability to attenuate vibration in frequency bands called "stop-bands". A periodic structure consists of cells which differ in material or geometry. As vibration waves travel along the structure and face the cell boundaries, some waves pass and some are reflected back, which may cause destructive interference with the succeeding waves. In this work, we analyze the flutter characteristics of a helicopter blades with a periodic change in their sandwich material using a finite element structural model. Results shows great improvements in the flutter forward speed of the rotating blade obtained by using periodic design and increasing the number of periodic cells.

Dyeing Characteristics of Polypropylene Fabric Dyed with Special Disperse Dyes Using Supercritical Carbon Dioxide

Tarek Abou Elmaaty,Hanan Elsisi,Ilham Negm 한국섬유공학회 2021 Fibers and polymers Vol.22 No.5

Using disperse dyes of different colors and hues to produce a variety of shades is necessary for the industrializationof supercritical fluid dyeing of polypropylene. Eight derivatives of 3-(3-chlorophenyl)-1-phenyl-4-(diazenyl derivatives)-1Hpyrazol-5-amine dye were synthesized explicitly for use in supercritical carbon dioxide medium. Polypropylene dyeing wasstudied in supercritical carbon dioxide under varying conditions: Dyeing temperatures ranged from 100 °C to 120 °C, dyingtimes ranged from 1 h to 2 h, concentrations ranged from 2 % owf (on the weight of fabric) to 4 %, and pressures ranged from15 to 25 MPa. Significant improvement of the colorfastness to washing and rubbing was observed. Raman spectroscopy wasperformed and showed conclusively that the dye was absorbed within all layers of polypropylene. This study achieved theelimination of water and its costly processing in the dyeing of synthetic fabrics.