1,720,995 research outputs found
Synthesis of Novel Rhodium Complex of Biphenylic-Imidazole-Phenanthroline and Photophysical Analysis of Metal Ions Selectively for Pb2+
No full text0000-0001-5025-9326WOS: 000377764300012A novel rhodium biphenylic-imidazole-phenanthroline metal-organic complex has been synthesized and the photophysical properties were studied against different metal ions. The rapid and sensitive detection of metal ions have an important impact on making the various environmental, biological and chemosensor devices. The new chemosensing properties have shown the affinity for Pb2+ toward Rhodium biphenyl-imidazole phenanthroline 6. These studies significantly conceded out that the UV/Vis and flourescent characteristic of the receptor has selectively responded at 344 nm with absorbance of 0.341 to the Pb2+, it is also obviously evident from the partial H-1-NMR results that the disappearance of NH at 7.129 and 10.081 ppm respectively. The remaining metal ions appeared small difference in their hypso- and hyperchromic shifts of UV/Vis results. Furthermore characterization and analytical studies of metal-organic complexes as chemosensors for different metal ions such as Ca2+, Cs+, Cu2+, Fe3+, K+, Mn2+, Na+, Pb2+, Sb+, Sn2+, Sn4+, and Zn2+ were carried using NMR, MS-ESI, Fluorescence and UV/Vis spectroscopic technique.Higher Education Commission of PakistanHigher Education Commission of PakistanWe are indebted to the Higher Education Commission of Pakistan for financial support and HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi for the availability of instruments and chemicals
Polyoxy-Derivatized Perylenediimide as Selective Fluorescent Ag (I) Chemosensor
No full textRecent investigations indicated that same concentrations of the ionic silver have harmful effects on aquatic life, bacteria and human cells. Herein we report chemosensory properties of N,N (') -Bis(4-{2-[2-(2-methoxyethoxy)ethoxy] eth- oxy}phenyl) -3,4:9,10-perylene tetracarboxydiimide (PERKAT) towards ionic silver. The dye doped sensing agents were prepared utilizing ethyl cellulose (EC) and poly (methylmethacrylate) (PMMA) and then forwarded to electrospinning to prepare sensing fibers or mats. The PERKAT exhibited bright emission in embedded forms in EC or in the solvents of N,N-Dimethylformamide (DMF), Dichloromethane (DCM), Tetrahydrofurane (THF) and in the mixture of DCM/ethanol. The PERKAT exhibited selective and linear response for ionic silver in the concentration range of 10(-10) - 10(-5) M Ag (I) at pH 5.5. Detection limits were found to be 2.6 x 10(-10) and 4.3 x 10(-11) M, in solution phase studies and PERKAT doped sensing films, respectively. Cross sensitivity of the PERKAT towards pH and some metal ions was also studied. There were no response for the Li+, Na+, K+, Ca2+, Ba2+, Mg2+, NH4 (+), Ni2+, Co2+, Cu2+,Pb2+, Al3+, Cr3+,Mn2+, Sn2+, Hg+, Hg2+, Fe2+ and Fe3+ in buffered solutions. To the best of our knowledge, this is the first study investigating silver sensing abilities of the PERKAT
Porphyrin-Based Dye-Sensitized Solar Cells (DSSCs): a Review
No full textThe current review aims to collect short information about photovoltaic performance and structure of porphyrin-based sensitizers used in dye-sensitized solar cells (DSSC). Sensitizer is the key component of the DSSC device. Structure of sensitizer is important to achieve high photovoltaic performance. Porphyrin derivatives are suitable for DSSC applications due to their thermal, electronic and photovoltaic properties. It describes some electrochemical and spectral properties as well as thestructure of porphyrin dyes used in dye based-solar cells
Synthesis of Biocompatible Double‐Tailed Nonionic Surfactants and Their Investigation for Niosomal Drug‐Loading Applications
No full textSaifullah, Salim/0000-0002-9790-1715; Ahmed, Farid/0000-0001-6466-7048WOS: 000474666800011Nonionic surfactants are capable of self-assembling and thus are of vital importance for designing various drug-delivery systems. This study reports the synthesis, characterization, biocompatibility, and drug-loading potential of sulfanilamide-based novel nonionic surfactants. These surfactants were synthesized in a single-step reaction and characterized using nuclear magnetic resonance (NMR), electron impact mass spectroscopy, and fourier-transforminfrared spectroscopy (FTIR). Critical micelle concentration (CMC) of the synthesized nonionic surfactants was determined using a ultraviolet-visible (UV) spectrophotometer. The surfactant potential for niosomal vesicles was explored using simvastatin as a model drug. The drug-loaded vesicles were screened for shape, size, size distribution, and percent drug entrapment efficiency (EE%) using atomic force microscopy (AFM), zeta potential, and UV-visible spectrophotometry. Biocompatibility of the synthesized surfactants was investigated through blood hemolysis and cell toxicity assays. Synthesized nonionic surfactants revealed lower CMC values of 0.045-0.095 mM and entrapped an improved amount of drug upon self-simplifying in niosomal vesicles. Findings of the study confirm these nonionic surfactants as hemocompatible and nontoxic candidates for vesicular drug-delivery applications
A novel Salvialactomine from the callus culture of <i>Salvia santolinifolia</i> Boiss
No full text0000-0001-5025-9326WOS: 000426946900001PubMed ID: 28412869A novel compound Salvialactomine (1) along with two other unusual occurring natural products Pentatriacontanoic acid 1, 3-dihydroxypropyl ester (2) and 5-Methylflavone (3) were isolated from the callus of Salvia santolinifolia Boiss. Callus was initiated on MS medium containing NAA (0.5 mg/L) and further sub-cultured on MS medium supplemented with NAA with BA (0.5 + 1.5 mg/L). The structures of isolated compounds were determined by using mass spectrometry, 1D, and 2D-NMR techniques. Compounds 1, and 3 were tested for two different cancer cell lines, i.e. Hela (Cervical cancer cell) and PC-3 (Prostate cancer cells). IC50 was found as > 30 using Doxorobicin (0.912 +/- 0.12 mu mol L-1) as a standard. [GRAPHICS]
EFFECTS OF MONO- AND INTERCROPPING ON GROWTH AND BORON UPTAKE OF WHEAT PLANT (TRITICUM AESTIVUM L.) CULTIVATED ON BORON-CONTAMINATED MEDIA
No full textNadeem, Said/0000-0001-5025-9326;WOS: 000363996600008Wheat plant (Triticum aestivum L.) was grown as main crop while clover (Medicago sativa L.) and sunflower (Helianthus annuus L.) were used as intercrops. Boron was applied in the form of Boric Acid (25, 50, & 75 mg L-1). The amount of chlorophyll, carotenoid, proline, B, Ca, K, and P were determined together with % DW and % EC. % DW, total chlorophyll, and carotenoid contents in monocrop and intercrop leaves grown wheat plants decreased in comparison with the control group. However, increases in mentioned parameters were observed in wheat-clover intercrops. Additionally, % EC values and proline contents in the leaves of mono-cultivated wheat plant were higher compared to the control group. Intercropping of wheat plant with clover and sunflower resulted in decreased values. Furthermore, element contents of the mono-cultivated wheat leaves decreased while these values increased when intercropping with clover
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Fluorescent supramolecular tweezers for selective recognition of cephradine
No full textNadeem, Said/0000-0001-5025-9326;WOS: 000348337700003Novel supramolecular molecular tweezers based on a biphenyl bis-triazole hexahydroquinoline system are designed and synthesized as a highly sensitive and selective fluorescent probe for recognizing and detecting cephradine in the presence of cefotaxime, amoxicillin, penicillin, 6-.aminopenicillanic acid, diclofenac, pefloxacin, ceftriaxone, cefaclor and paracetamol at a pH of 7.7. The detection limit is calculated to be 1 mu M with a regression coefficient of 0.99. The binding ratio of the tweezers and cephradine is determined to be 1:1 according to ESI-MS analysis, which is further supported by the Job plot. The structure of the supramolecular molecular tweezers and its precursors are characterized by IR, NMR, mass spectroscopy and XRD. (C) 2014 Elsevier Ltd. All rights reserved.Higher Education Commission of PakistanHigher Education Commission of Pakistan; TWAS-COMSTECHWe gratefully acknowledge the financial support of the Higher Education Commission of Pakistan and TWAS-COMSTECH. We are also thankful to Mr. Ateeq for help in characterization
One Pot Synthesis of 1,10-Phenanthroline-based Shape-Persistent Flouroscent Macrocycle Using Sonogashira Coupling
No full textNadeem, Said/0000-0001-5025-9326;WOS: 000357692800009A rigid shape-persistent fluorescent macrocycle PhenMac was synthesized using Sonogashira coupling reaction and TIPS-decoupling in a single pot. 2,9-dichloro-1,10-phenanthroline was reacted with TIPS-protected diyne 2 in the presence of Pd(PPh3)(2)Cl-2, CuI and TBAF at 100 degrees C. PhenMac was obtained as yellow fluorescent compound; characterized by NMR, ESI, MALDI-TOF, CHN, IR and UV-visible spectroscopy. In chloroform, PhenMac showed lambda(ex-max) at 331 nm while lambda(em-max) was observed at 407 nm. Under UV light, PhenMac showed more fluorescence in CHCl3, ethanol, and DMF while the fluorescence was quenched in triethylamine. PhenMac will be used in various applications of [poly]catenanes, supramolecular chemistry and nanotechnology.Higher Education Commission of PakistanHigher Education Commission of PakistanWe are thankful to the Higher Education Commission of Pakistan for financial support International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, University of Karachi, Pakistan for all facilities used during the project
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