Stable and effective super-hydrophilic polysulfone nanofiber mats for oil/water separation

Obaid, M.,Barakat, Nasser A.M.,Fadali, Olfat A.,Al-Meer, Saeed,Elsaid, Khalid,Khalil, Khalil Abdelrazek Elsevier 2015 Polymer Vol.72 No.-

<P><B>Abstract</B></P> <P>Hydrophobicity of polysulfone is the main constraint facing wide application in the most important field; water treatment, although this polymer shows promising characteristics to be used in different separation technologies. In this study, super-hydrophilic polysulfone nanofiber mats are introduced using novel modifications. The introduced nanofibers were synthesized by electrospinning of polysulfone/NaOH/DMF electrospun solution. The prepared electrospun nanofibers have been activated by deposition of a polyamide layer using interfacial polymerization (IP) reaction between m-phenylenediamine and 1,3,5-benzenetricarbonyl chloride. Three different heat treatment methodologies were investigated to enhance the characteristics of the activated nanofiber mats; normal drying at 70 °C, and soaking in boiled water followed by either normal drying at 70 °C or storing in the water. Investigation of the mechanical properties indicated that incorporation of NaOH improves the tensile stress by 40% compared to the pristine polysulfone nanofibers. Interestingly, treatment of the activated nanofiber mats in the boiled water followed by storing in water led to produce super-hydrophilic mats with water contact angle of 3° due to enhancing the IP reaction on the surface of the individual nanofibers. In oil/water separation process, the proposed heat treatment for the modified nanofiber mats resulted in increase the water flux from 8 to 12.21 m<SUP>3</SUP>/m<SUP>2</SUP> day with oil rejection of 99.976%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Super-hydrophilic membrane based on PSF nanofibers is introduced. </LI> <LI> The membrane was modified using simple and effective heat treatment process. </LI> <LI> The corresponding water flux is very high; 12.21 m<SUP>3</SUP>/m<SUP>2</SUP> day. </LI> <LI> The fabrication process is simple, cheap and applicable. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis, molecular docking studies of coumarinyl-pyrazolinyl substituted thiazoles as non-competitive inhibitors of mushroom tyrosinase

Saeed, A.,Mahesar, P.A.,Channar, P.A.,Abbas, Q.,Larik, F.A.,Hassan, M.,Raza, H.,Seo, S.Y. Academic Press 2017 Bioorganic chemistry Vol.74 No.-

A series of coumarinyl-pyrazolinyl substituted thiazoles derivatives were synthesized and their inhibitory effects on the DPPH and mushroom tyrosinase were evaluated. The results showed that all of the synthesized compounds exhibited significant mushroom tyrosinase inhibitory activities. In particular, 3-(5-(4-(benzyloxy)-3-methoxyphenyl)-1-(4-(4-bromophenyl)thiazol-2-yl)-4,5-dihydro-1H-pyrazol-3-yl)-2H-chromen-2-one (7j) exhibited the most potent tyrosinase inhibitory activity with IC<SUB>50</SUB> value 0.00458+/-0.00022μM compared with the IC<SUB>50</SUB> value of kojic acid is 16.84+/-0.052μM. The inhibition mechanism analyzed by Lineweaver-Burk plots revealed that the type of inhibition of compound 7j on tyrosinase was noncompetitive. The docking study against tyrosinase enzyme was also performed to determine the binding affinity of the compounds. The compound 7a showed the highest binding affinity (-10.20kcal/mol) with active binding site of tyrosinase. The initial structure activity relationships (SARs) analysis suggested that further development of such compounds might be of interest. The statistics of our results endorses that compound 7j may serve asa structural template for the design and development of novel tyrosinase inhibitors.

Characterization and mechanism of the adsorptive removal of 2,4,6-trichlorophenol by biochar prepared from sugarcane baggase

S. Mubarik,A. Saeed,M.M. Athar,M. Iqbal 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

Biochar from sugarcane baggase was prepared by heating at high temperature for 20 min. Surfaceproperties of the biochar were determined by Boehm titrations and FTIR. Biochar has 50.47% fixed carbonhaving methylene blue surface area of 361.77 m2/g. SEM image revealed that biochar has cylindrical,well shaped porous structures that increase surface area for adsorption. Operational parameters for2,4,6-TCP adsorption were optimized. The experimental qmax was found to be 253.38 mg/g. Biocharremoved 2,4,6-TCP in the presence of multiple pollutants. The functional moieties present on biocharshowed their affinity for 2,4,6-TCP 6¼ methylene blue > phenol > mercury.

Stem cell-derived exosomes for dentin-pulp complex regeneration: a mini-review

Hammouda Dina A.,Mansour Alaa M,Saeed Mahmoud A.,Zaher Ahmed R.,Grawish Mohammed E. 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.2

This mini-review was conducted to present an overview of the use of exosomes in regenerating the dentin-pulp complex (DPC). The PubMed and Scopus databases were searched for relevant articles published between January 1, 2013 and January 1, 2023. The findings of basic in vitro studies indicated that exosomes enhance the proliferation and migration of mesenchymal cells, as human dental pulp stem cells, via mitogen-activated protein kinases and Wingless-Int signaling pathways. In addition, they possess proangiogenic potential and contribute to neovascularization and capillary tube formation by promoting endothelial cell proliferation and migration of human umbilical vein endothelial cells. Likewise, they regulate the migration and differentiation of Schwann cells, facilitate the conversion of M1 pro-inflammatory macrophages to M2 anti-inflammatory phenotypes, and mediate immune suppression as they promote regulatory T cell conversion. Basic in vivo studies have indicated that exosomes triggered the regeneration of dentin-pulp–like tissue, and exosomes isolated under odontogenic circumstances are particularly strong inducers of tissue regeneration and stem cell differentiation. Exosomes are a promising regenerative tool for DPC in cases of small pulp exposure or for whole-pulp tissue regeneration.

Enhancement of the electrical properties of carbon nanotubes with AreN2 plasma treatment

M. Abrar,G.U. Farwa,S. Naseer,A. Saeed,A.W. Khan,Z. Iqbal,S. T. Hussain,M. Zakaullah 한국물리학회 2013 Current Applied Physics Vol.13 No.3

Optical emission spectroscopy and Langmuir probe are used to investigate the low pressure inductively coupled AreN2 plasmas as function of rf power, filling pressure and Ar content in N2 discharge. It is observed that the active species generation, dissociation fraction and electron temperature significantly depends on discharge parameters and may be used to optimize the plasma reactor. Mixture of SWCNTs and MWCNTs are treated for different treatment time (0e120 min) at optimum discharge conditions. Changes induced in the elemental composition, surface morphology, crystallographic structure, and structural disorder in the plasma irradiated CNTs are analyzed by EDX, FTIR, SEM, XRD and Raman spectroscopy, respectively. AreN2 mixture plasma treatment of CNTs lead to a significant increase in the electrical conductivity, modify the microstructure and induce structural disorder and cause a transition of crystalline phase from well crystalline to an amorphous structure.

Used lubricating oil regeneration by various solvent extraction techniques

SAEED M. AL ZAHRANI,Meilana Dharma Putra 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

The used lubricating oil regeneration using extraction technique has been widely known as one of the cheapest and most competent processes. The best performance of solvent was shown by R-11 as the lowest percent oil losses, followed by CFC-113, MEK, 1-butanol, and 2-propanol. This performance sequence could be also evaluated by method of solubility parameter difference (Es) using Hildebrand and Peng–Robinson EoS approaches. The effectiveness of extraction parameters was also studied. The percent oil losses decreased with the extraction temperature. The values of optimum ratio of solvent to oil obtained by the Es method gave reasonable results compared to the experimental method.

Synthesis, Characterization and Biological Activity of a Series of Carboxamide Derivatives of Ofloxacin

M. Saeed Arayne,Najma Sultana,M. Hashim Zuberi,Syeda Bushra Shakeb Rizvi,Urooj Haroon 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.12

The present study was designed to help develop new agents with better antimicrobial profiles. Specifically, we focused on modification of the basic structure of ofloxacin by introducing new functionality at its C3 position. For this purpose, the carboxylic group at the C3 position of ofloxacin was replaced by an amide group through an ester aminolysis reaction. The structure of these derivatives was established by various analytical techniques i.e., IR, 1H-NMR, 13CNMR CHNS elemental analysis and mass spectrometry. The antibacterial activity of ofloxacin and its derivatives against ten different Gram-positive and Gram-negative microorganisms was studied using a disk susceptibility method. These compounds were further tested for their activity against various fungi and compared to ofloxacin. The synthesized compounds showed diverse antimicrobial profiles. Among them, a few compounds possessed a comparable or better activity in comparison to the reference drug.

Studies on the Effects of Piperidine Derivatives on Blood Pressure and Smooth Muscles Contractions

Saeed, M.,Saify, Z.S.,Gilani, A.H.,Iqbal, Z. The Pharmaceutical Society of Korea 1998 Archives of Pharmacal Research Vol.21 No.4

Ten substituted phenacyl derivatives of 4-hydroxypiperidine were synthesized and studied for their effects on the mean arterial blood pressure (MABP) in normotensive anaesthetized rats and smooth muscles contractions of isolated rabbit jejunum. Two derivatives caused fall in blood pressure at the dose of 10-20 mg/kg and one rise in blood pressure at the dose of 20 mg/kg. Two compounds exhibited biphasic response (hypotensive followed by hypertensive) and one gave triphasic response at 10 mg/kg dose. Rest of four derivatives were found devoid of any effect on mean arterial blood pressure up to the dose of 30 mg/kg. All the derivatives except two caused relaxant effect on the spontaneous contraction of rabbit jejunum at the dose range of 0.1 -2 mg/kg.

Investigation of key parameters influence on performance of direct ethanol fuel cell (DEFC)

Saeed Heysiattalab,Mehdi Safari,Mohsen Shakeri,M.M. Keikha 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.4

Direct ethanol fuel cell has been declared as a new alternative for other fuel cells such as direct methanol fuel cell and proton exchange membrane fuel cells. In this paper, effects of key parameters such as temperature, anode and cathode flow rate, molarity and cathode pressure have been investigated on ethanol fuel cell performance. Maximum power density and fuel cell performance will increase by temperature rising because of ion conductivity, diffusion and reaction rate increase. Molarity augmentation will increase ethanol concentration in catalyst layer and reaction rate which leads to better performance of the cell. Anode and cathode flow rate and cathode pressure will slightly increase fuel cell performance.

Synthesis and Biological Evaluations of Enoxacin Carboxamide Derivatives

M. Saeed Arayne,Najma Sultana,Urooj Haroon,M. Ahmed Mesaik,Muhammad Asif 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.7

The present work deals with the synthesis of various enoxacin analogues via nucleophilic substitution of 3- carboxylic acid moiety of the drug by aromatic amines. The free carboxylic group was utilized in the formation of amides and the effect of functional group exchange on different biological activities of the parent was evaluated. The structure of these derivatives was established by various spectroscopic techniques and mass spectrometry. The derivatives were evaluated as antibacterial agents against a series of Gram-positive and Gram-negative bacteria whereby some of them displayed considerably improved antimicrobial profile against Gramnegative test strains. Additionally unlike enoxacin, the derivatives were also found to modulate oxidative burst response of phagocytes exhibiting moderate to significant inhibitory activity.