Life Sciences Commons^™

Ceramide Kinase Regulates Phospholipase C And Phosphatidylinositol 4, 5, Bisphosphate In Phototransduction, Ujjaini Dasgupta, Takeshi Bamba, Salvatore Chiantia, Pusha Karim, Ahmad N. Abou Tayoun

Dartmouth Scholarship

Phosphoinositide-specific phospholipase C (PLC) is a central effector for many biological responses regulated by G-protein-coupled receptors including Drosophila phototransduction where light sensitive channels are activated downstream of NORPA, a PLCbeta homolog. Here we show that the sphingolipid biosynthetic enzyme, ceramide kinase, is a novel regulator of PLC signaling and photoreceptor homeostasis. A mutation in ceramide kinase specifically leads to proteolysis of NORPA, consequent loss of PLC activity, and failure in light signal transduction. The mutant photoreceptors also undergo activity-dependent degeneration. Furthermore, we show that a significant increase in ceramide, resulting from lack of ceramide kinase, perturbs the membrane microenvironment of …

Decreased Replication Origin Activity In Temporal Transition Regions, Zeqiang Guan, Christina M. Hughes, Settapong Kosiyatrakul, Paolo Norio, Ranjan Sen, Steven Fiering

Dartmouth Scholarship

In the mammalian genome, early- and late-replicating domains are often separated by temporal transition regions (TTRs) with novel properties and unknown functions. We identified a TTR in the mouse immunoglobulin heavy chain (Igh) locus, which contains replication origins that are silent in embryonic stem cells but activated during B cell development. To investigate which factors contribute to origin activation during B cell development, we systematically modified the genetic and epigenetic status of the endogenous Igh TTR and used a single-molecule approach to analyze DNA replication. Introduction of a transcription unit into the Igh TTR, activation of gene transcription, …

Chemistry In Second Life, Andrew Lang, Jean-Claude Bradley

College of Science and Engineering Faculty Research and Scholarship

This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students.

Inhibition Of Rna Recruitment And Replication Of An Rna Virus By Acridine Derivatives With Known Anti-Prion Activities, Zsuzsanna Sasvari, Stéphane Bach, Marc Blondel, Peter D. Nagy

Plant Pathology Faculty Publications

BACKGROUND: Small molecule inhibitors of RNA virus replication are potent antiviral drugs and useful to dissect selected steps in the replication process. To identify antiviral compounds against Tomato bushy stunt virus (TBSV), a model positive stranded RNA virus, we tested acridine derivatives, such as chlorpromazine (CPZ) and quinacrine (QC), which are active against prion-based diseases.

METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that CPZ and QC compounds inhibited TBSV RNA accumulation in plants and in protoplasts. In vitro assays revealed that the inhibitory effects of these compounds were manifested at different steps of TBSV replication. QC was shown to have an effect …

Stability Of Antimony And Its Anodic Oxide Film Against Corrosion In Aqueous Solutions, A. El Maghraby, A. Mogoda

Al-Azhar Bulletin of Science

The open circuit potential and impedance measurements were used to investigate the corrosion behavior of antimony in 0.1M citric acid solution made to various pH values. The results showed that the antimony surface undergoes spontaneous corrosion in the citrate solutions. Also the properties of the anodic oxide film on antimony were examined by impedance technique. It was found that the antimony surface becomes more passive as the thickness of the anodic oxide film formed on antimony increase. The anodic oxide film on antimony behaves like a non- ideal capacitor. The stability of the anodic oxide film in the aqueous solutions …

Conductometric Investigation Of Magnesium (Ii), Calcium (Ii) And Barium (Ii) Complexes In Aqueous Solution, Abd Allah Mohamed, Wadie Al–Ariqui, Moustafa Bakr

Al-Azhar Bulletin of Science

The ionic association constants, KA, of Mg, Ca and Ba metal ions with succinate, malate and tartrate ligands were conductometrically determined in water at 25–40oC. The conductometric data were analysed by the Shedlovsky extrapolation method. The KA values tend to decrease with the cation size in the order Ca > Ba for all the salts under study with the exception of Mg salts, whereas the KA values for the ligands increase in the order succinate < malate < tartrate. For the salts under study, standard thermodynamic functions, Ho and So for the association were evaluated and discussed. The positive values of both Ho and So in all the systems indicate the ionic association processes are the reactions of unfavorable enthalpy and favorable entropy changes in aqueous solution. The thermodynamic metal gradient, , was evaluated and its significance of ion association of all salts under investigation was discussed. On the other hand, the results of limiting molar conductance, o, are discussed on the light of Walden product.

Physicochemical Studies On Some Hydrazone Complexes, Hamdy Hammad

Al-Azhar Bulletin of Science

Some hydrazones and their complexes were prepared in order to study their molecular structures. The hydrazones were prepared by condensing p-aminobenzoic acid hydrazide with some aldehydes. The of Cu(II), Ni(II) and Co(II) were prepared and characterized by elemental analysis, magnetic, electronic and IR methods.

Part 1: Synthesis And Reactions Of Some New Pyrazolo[4,5-D]Imidazole Derivatives And Screening Their Antibacterial And Antitumor Activities, Nahed Abd El-Ghaffar, Mona Kadah, Azza Radwan, Sara Abd El-Al, Asmaa Salman

Al-Azhar Bulletin of Science

Reaction of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one with diazotized aromatic amines gave the corresponding diazenyl derivatives 1, which were condensed with carbonyl compounds to give the arylidene derivatives 2. Reaction of the parent pyrazolone with urea, thiourea and guanidine gave the pyrazoloimidazole derivatives 3. compound 3a reacted with thiourea in DMF to give the thiourea derivative 4. The reaction of 4 with malonic acid and acetyl chloride gave the pyrimidinedione derivative 5, which on reaction with thiourea in presence of sodium ethoxide gave the triazine derivative 6. S-alkylation of 6 with ethyl chloroacetate gave the ethyl acetate derivative 7, which on hydrolysis gave the …

The Electropolymerization Of Bithiophene And 3-Methylthiophene Copolymer And Their Electrochemical Relaxation Studies, G. Abou-Elenien, A. El Maghraby, A. Kotb

Al-Azhar Bulletin of Science

The electrosynthesis of the copolymer of bithiophene and 3-methylthiophene has been investigated using galvanostatic and potentiodynamic techniques. The most stable films were obtained using galvanostatic technique in acetonitrile solvent and TBAPF6 as supporting electrolyte. A comparison study was performed for the prepared copolymer and homopolymer films whose were subjected to a relaxation studies using cyclic voltammetric technique in different solvents. The effect of solvent, monomer concentration ratio, electrocopolymerization techniques and temperature on the relaxation time were investigated.

Electrochemical Relaxation Study Of Polythiophene As Conducting Polymer (Ii), G. Abou-Elenien, A. El Maghraby, G. El-Abdallah

Al-Azhar Bulletin of Science

The electrosynthesis of polythiophene films from thiophene, 2, 2′:5, 2″-terthiophene,3-methylthiophene and 3-bromothiophene monomers were investigated using different electrochemical techniques. The stability and electrical conductivity of the prepared films were studied. The most stable polythiophene film was obtained using galvanostatic technique in acetonitrile solvent and TBAPF6 as supporting electrolyte at 5°C, except in case of electropolymerization of 3- bromothiophene the most stable film was obtained potentiodynamically. The relaxation kinetics of the films were extensively studied. It was found that a very thin film would hardly show the slow relaxation. Also by using TBAPF6 as electrolyte, the most sensitive film was obtained, …

Surface Investigations Of Aluminum In 2m Hydrochloric Acid Solution In The Presence Of Potassium Iodate Inhibitor, A. El Maghraby

Al-Azhar Bulletin of Science

The results of investigations by using optical, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to study the surface morphology, the composition of adsorbed film formed on the surface of aluminum samples in 2M hydrochloric acid solution containing ppm optimum KIO3 dose. The data reveal that the additive improves the surface morphology of aluminum, due to the marked layer enrichment of Al- surface by inhibitor components. Detailed studies were carried out to investigate the effect of oxygen in the inhibition process. The nature and strength of the passive film and the mechanism of its formation are explained based …

Synthesis And Antimicrobial Activity Of Some Nitrogen Heterocycles Incorporation Into Coumarin, Nahed Abd El-Ghaffar

Al-Azhar Bulletin of Science

3-Carbethoxycoumarin derivatives were reacted with some neucleophilic reagents such as amines, hydrazines, urea derivatives and amino acids in order to study their effect on coumarin nucleus especially carbonyl coumarin and synthesis of new derivatives which have biological effects on microorganisms such as bacteria and fungi. The structural assignments of the new compounds were based on analytical and spectral data.

Tantalum As An Indicator Electrode In Different Potentiometric Titrations, Enas Attia

Al-Azhar Bulletin of Science

Tantalum metal was employed as an indicator electrode in different potentiometric titrations. Silver, platinum and SCE were successfully applied as reference electrodes. A number of classical acid/base reactions were chosen. This involve titration of strong and weak mono- and poly basic acids; HCl, H2SO4, H3PO4, HCOOH and H2C2O4 with NaOH and NH4OH. Both forward and backward titrations were carried out. The titration performed until the greatest jump of potential appeared by adding one drop of titrant. Both forward and backward titration curves showed marked potential inflexions which recorded at the theoretically calculated equivalence points. Bimetallic combinations were equally suitable for …

Part 2: Synthesis And Reactions Of Some New Imidazo[4,5-C]Pyrazole And Pyrazolo[3,4-D]Pyrimidine Derivatives, Mona Kadah, Nahed Abd El-Ghaffar, Azza Radwan, Sara Abd El-Al, Asmaa Salman

Al-Azhar Bulletin of Science

Reactions of 3-methyl-1-phenyl-4,6-dihydroimidazo[4,5-c]pyrazole-5(1H)-thione with carbonyl compounds gave the arylidene derivatives 2 and 3, with recinoleic acid, phosphorus oxychloride/phosphorus pentachloride mixture and copper bronze gave the adduct 4, the chloro derivative 5 and the dimer with desulfurization 7. The behaviour of the chloroderivative towards hydrazine and primary amines have also been studied. On the other, reaction of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one with aromatic aldehydes gave the arylidene derivatives 8a-d, which on reaction with thiourea gave the pyrazolopyrimidinethione derivatives 9. The behaviour of compounds 9 towards copper bronze, sodium nitrite/acetic acid mixture, acrylonitrile and formaldehyde/ morpholine and its reaction with compound 1 in presence of …

Various Modified Polyesteramide Varnishes As Antimicrobial Growth Control., M. Mostafa, A. Naser, F. Abdel-Hai, H. Abd El-Wahab

Al-Azhar Bulletin of Science

New modified polyesteramide compositions were prepared and evaluated as vehicles for surface coating The resin was prepared by partial replacement of hydroxyl ethyl fatty acid amide (HETSA) by N,N-Bis(2-hydroxyethyl) -p-toluenesulfonamide .This modification, as expected, imp- roved the film performance and durability and lead to substantial antimicrobial growth control.

Synthesis Of Some Benzofuranyl Thieno[2,3-D] Pyrimidine Derivatives With Biological Interest, Nadia Taha, Enas Islam, Nermin Marzok, Abeer Elatrash, Jehane Micky

Al-Azhar Bulletin of Science

Interaction of visnaginone or khellinone (1a,b) with cyanoacetamide, ethyl cyanoacetate or molanonitrile and elemental sulfur in presence of triethylamine afforded thiophene enamino derivatives (2a-d) respectively according to Gewald method. Acetylation of 2a with acetic anhydride gave 3. Condensation of 2b with p-chlorobenzaldehyde yielded 4. Compound 6 was afforded from reaction of enamino carboxamide (2b) with thiourea.. Compound 2b reacted with benzoyl chloride to give thienopyrimidine (8). N-phenyl thienopyrimidine (11) and N-amino thienopyrimidine (13) were prepared from reaction of 2c with phenyl isothiocyanate and hydrazinolysis of 12 with hydrazine hydrate. The structures of these compounds were confirmed by infrared, mass and …

Synthesis Of Some Novel Thiazole, Thiophene, Thienopyridine And Thienopyrimidine Derivatives Containing Tosyl Moiety, S. Hessien, Mona Kadah, N. Marzouk

Al-Azhar Bulletin of Science

Interaction of 4-aminoacetophenone (1) with p-tolyl sulphonamide afforded 1-[4-tosyl amino) phenyl]ethanone (2). Treatment of 2 with bromine water yielded 2-bromo-1-[4-tosyl amino) phenyl]ethanone (3), which reacted with thiourea to give 2-amino thiazole derivative (4). Compound 2 was condensed with phenyl acetaldehyde and malononitrile to give derivatives (5) and (7), which were respectively reacted with o-aminothiophenol and carbon disulfide to give derivatives (6) and (9). Reaction of 7 under Gewald reaction condition afforded the thiophen-3-carbonitrile derivative (11) which consequently reacted with 4-fluorobenzylidinemalononitrile, phenyl isothiocyanate to give compounds 12 and 15, respectively. The structures of these compounds were confirmed by infrared, mass and …

Expired Ranitidine Drugs As Corrosion Inhibitor For Corrosion Of Aluminium In Hydrochlric Acid, Reda Abdel Hameed

Al-Azhar Bulletin of Science

The corrosion behavior of aluminum in 1M HCl solution in the absence and presence of expired Ranitidine drug was investigated using weight loss and electrochemical techniques. It was found that, the inhibition efficiency of Ranitidine depends on the concentrations. The inhibitive action of this compound discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in its structure. The adsorption process follows Langmuir adsorption isotherm and El-Awady isotherm. The polarization curves indicate that this compound may act as mixed-type inhibitor. The variation of the open circuit potential of the aluminum electrode as …

Vibrational Spectrum And Thermodynamic Properties Of Pyridazine, Zeinab El-Shafie, Ahmed Shabana

Al-Azhar Bulletin of Science

Vibrational spectrum of pyridazine was recorded. Assignment of frequencies to normal vibrations was made. Tellr-Redlich product rule was applied for symmetry species A1, A2, B1 and B2. Thermodynamic functions were calculated from spectroscopic data.

Novel Imides Amino Acids And Dipeptide Derivatives, Ragab El-Sayed

Al-Azhar Bulletin of Science

Some novel imides derivatives condensed with different amino acids using THF-Et3N method, afforded an excellent yield of compounds 3-8, 20-23b, 32-35b. some of these compounds react with CH3OH-SOCl2 mixture to give corresponding methyl esters 9-11, 24-25, 36-37 Hydrazinolysis of some methyl esters give hydrazides 12-14, 26-27 some dipeptides derivatives 15-17, 28-29, 38-40 were prepared using Dicyclohexylcarbodiimide DCC method, some spectra data were briefly discussed.

Studies On Corrosion Inhibition Of C-Steel In 1m Acetic Acid Solutions By Ethoxylated Poly (Ethylene Terphthalate) Derived From Plastic Waste, Reda Abdel Hameed, H. Al-Shafey, E. Ismail

Al-Azhar Bulletin of Science

The inhibition of three ethoxylated poly (ethylene terphthalate), derived from plastic waste by reacting of PET with triethanol amine followed by reacting with polyethylene glycol, (PEG), which has different molecular weights 400, 1000 and 4000. On the corrosion of steel in 1M acetic acid solutions have been studied at different temperatures (30-60°C) by weigh loss. The inhibition efficiency for the three compounds increased with increasing of the inhibitors concentrations and temperatures. The inhibition efficiency for the three inhibitors decrease in the order (Tn= 9< 22< 90). The polarization curves indicate that these compounds act as mixed-type inhibitors. The inhibition occurs through adsorption of the inhibitor molecules on the metal surface without modifying the mechanism of corrosion process. Langmuir adsorption isotherms fit well the experimental data of dissolution and adsorption were calculated and discussed.

New Modified Polyesteramide Compositions As Vehicles For Surface Coatings., Salem Aqeel, H. Abd El-Wahab, Abdulsalam Mahdy, F. Abd El-Hai

Al-Azhar Bulletin of Science

New modified polyesteramide compositions were prepared and evaluated as anticorrosive varnish. The resin prepared by partial replacement of hydroxy ethyl fatty acid amide (HEFA) by polyethylene glycol (PEG) without affecting the resin constants. Primer formulations based on this resin showed good corrosion inhibiting properties.

Validation Of Ozone Measurements From The Atmospheric Chemistry Experiment (Ace), Nicholas B. Jones, David W. Griffith, M Wolff, E Mahieu, G Bodeker, I Boyd, M De Maziere, P Demoulin, T Blumenstock, Y. Murayama, A. Kagawa, J Jin, Christopher Mcelroy, J Hannigan, M Coffey, M Hopfner, H W. Fischer, T Kerzenmacher, I Kramer, J Mellqvist, R Sussmann, K Strong, J R. Taylor, K Mizutani, Y Kasai, J Urban, D Murtagh, E Dupuy, V Catoire, S Chabrillat, P Baron, C Brogniez, G L. Manney, C Piccolo, C Randall, C Robert, C Senten, C Tetard, N J. Livesey, A Kleinbohl, S Godin-Beekmann, T Borsdorff, James Drummond, C De Clercq, J C. Lambert, U Cortesi, K W. Jucks, C Boone, H Oelhaf, M Schneider, T Steck, K A. Walker, P Bernath, T Von Clarmann, R Hughes, C Vigouroux, J Kuttippurath, A Bracher, J Mcconnell, C Mclinden, H Kullmann, L Froidevaux, J Dodion, F Vanhellemont, J P. Burrows, J Kar, F Goutail, D G. Dufour, J M. Zawodny, F Nichitiu, J-P Pommereau, C Nowlan, D Fussen, J Zou, A R Klekociuk, G Forbes, H Bovensmann, R M Bevilacqua, C Haley, S Ceccherini, S D Mcleod, P Gerard, R Skelton, B Firanski, A E Bourassa, D A Degenstein, J Davies, T Christensen, J Granville, A Parrish, C Roth, J W. Waters, C Von Savigny, A Standberg, M Mchugh, A M. Thompson, E J Llewellyn, P Von Der Gathen, M B. Tully, J C. Witte, C Roth, B T. Marshall, K B. Strawbridge, E Kyrola, M P. Mccormick, D P J Swart, N D Lloyd, D W. Tarasick, S V. Petelina, L W. Thomason, A Jones, I S. Mcdermid

Faculty of Science - Papers (Archive)

This paper presents extensive bias determination analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE) satellite instruments: the ACE Fourier Transform Spectrometer (ACE-FTS) and the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO) instrument. Here we compare the latest ozone data products from ACE-FTS and ACE-MAESTRO with coincident observations from nearly 20 satellite-borne, airborne, balloonborne and ground-based instruments, by analysing volume mixing ratio profiles and partial column densities. The ACEFTS version 2.2 Ozone Update product reports more ozone than most correlative measurements from the upper troposphere to the lower mesosphere. At altitude levels from …