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21.
A novel dinuclear copper(I) complex, [Cu2(μ2-SH)2(PPh3)3] (1) (PPh3 = triphenylphosphine) has been prepared by the reaction of CuCl with triphenylphosphine and mercaptopropanoic acid (MPA) mixed in the ratio of 1:1:1. In the molecular structure of 1, two copper atoms are bridged by S atoms of two monohydrogensulfido anions forming a four-membered ring. The planar Cu2S2 core is characterized by significant cuprophilic interactions (Cu-Cu distance = 2.897 ?). One copper atom in 1 is coordinated with two sulfur atoms and one phosphorus atom of PPh3 adopting a trigonal planar geometry, while the coordination environment around the other copper center is distorted tetrahedral that is completed by two sulfur atoms of SH groups and two phosphorus atoms of PPh3 molecules. 相似文献
22.
Syed T Akhtar T Al-Masoudi NA Jones PG Hameed S 《Journal of enzyme inhibition and medicinal chemistry》2011,26(5):668-680
2-(1-[(4-Chloro/methylphenylsulfonylamino)alkyl]-5-thioxo-4,5-dihydro-1,3,4-oxadiazoles (4a-e) were synthesized, in four steps, via the sulfonyl derivatives of l-amino acids (l-alanine, l-methionine and l-phenylalanine) 1a-e, the esters 2a-e, the hydrazides 3a-e and finally the cyclization to 4a-e. Alkylation of 4a-e with 1.0 mole eq. of substituted benzyl halides furnished S-benzyl derivatives 5a-t, while 1.1 mole eq. yielded major 5a-t and minor amount of 6a-d. Alternatively, treatment of 4a-e with 2.0 mole eq. of substituted benzyl halides furnished 6a-d only. The structures of 5b and 5l were further confirmed by single crystal X-ray analysis. Compounds 5a-t and 6a-d showed no selective inhibition against HIV-1 and HIV-2 replication in MT-4 cells. However, 5f and 5j-5q exhibited some inhibitory activity against both types with EC(50) values (>11.50 - >13.00 μg/mL). These results suggest that the structural modifications of these compounds might lead to the development of new antiviral agents. The quantum structure-activity relationship of these novel structural congeners is discussed. 相似文献
23.
In vitro 3D cancer models that provide a more accurate representation of disease in vivo are urgently needed to improve our understanding of cancer pathology and to develop better cancer therapies. However, development of 3D models that are based on manual ejection of cells from micropipettes suffer from inherent limitations such as poor control over cell density, limited repeatability, low throughput, and, in the case of coculture models, lack of reproducible control over spatial distance between cell types (e.g., cancer and stromal cells). In this study, we build on a recently introduced 3D model in which human ovarian cancer (OVCAR-5) cells overlaid on Matrigel™ spontaneously form multicellular acini. We introduce a high-throughput automated cell printing system to bioprint a 3D coculture model using cancer cells and normal fi broblasts micropatterned on Matrigel™. Two cell types were patterned within a spatially controlled microenvironment (e.g., cell density, cell-cell distance) in a high-throughput and reproducible manner; both cell types remained viable during printing and continued to proliferate following patterning. This approach enables the miniaturization of an established macro-scale 3D culture model and would allow systematic investigation into the multiple unknown regulatory feedback mechanisms between tumor and stromal cells and provide a tool for high-throughput drug screening. 相似文献
24.
Tayyaba Yasmin Inayat Ur Rehman Adnan Ahmad Ansari Khurrum liaqat Muhammad Irfan khan 《Bioinformation》2012,8(25):1277-1279
The availability of genomic sequences of many organisms has opened new challenges in many aspects particularly in terms of
genome analysis. Sequence extraction is a vital step and many tools have been developed to solve this issue. These tools are
available publically but have limitations with reference to the sequence extraction, length of the sequence to be extracted, organism
specificity and lack of user friendly interface. We have developed a java based software package having three modules which can
be used independently or sequentially. The tool efficiently extracts sequences from large datasets with few simple steps. It can
efficiently extract multiple sequences of any desired length from a genome of any organism. The results are crosschecked by
published data.
Availability
URL 1: http://ww3.comsats.edu.pk/bio/ResearchProjects.aspxURL 2: http://ww3.comsats.edu.pk/bio/SequenceManeuverer.aspx 相似文献25.
Anum Jazba O’Shea Charlotte Zeeshan Hyder M. Farrukh Sumaira Skriver Karen Malik Saad Imran Yasmin Tayyaba 《Molecular biology reports》2022,49(1):293-302
Molecular Biology Reports - Germin-like proteins (GLPs) are ubiquitous plant proteins, which play significant role in plant responses against various abiotic stresses. However, the potential... 相似文献
26.
An outstanding problem in cancer therapy is the battle against treatment-resistant disease. This is especially true for ovarian cancer, where the majority of patients eventually succumb to treatment-resistant metastatic carcinomatosis. Limited perfusion and diffusion, acidosis, and hypoxia play major roles in the development of resistance to the majority of front-line therapeutic regimens. To overcome these limitations and eliminate otherwise spared cancer cells, we utilized the cationic photosensitizer EtNBS to treat hypoxic regions deep inside in vitro 3D models of metastatic ovarian cancer. Unlike standard regimens that fail to penetrate beyond ~150 μm, EtNBS was found to not only penetrate throughout the entirety of large (>200 μm) avascular nodules, but also concentrate into the nodules' acidic and hypoxic cores. Photodynamic therapy with EtNBS was observed to be highly effective against these hypoxic regions even at low therapeutic doses, and was capable of destroying both normoxic and hypoxic regions at higher treatment levels. Imaging studies utilizing multiphoton and confocal microscopies, as well as time-lapse optical coherence tomography (TL-OCT), revealed an inside-out pattern of cell death, with apoptosis being the primary mechanism of cell killing. Critically, EtNBS-based photodynamic therapy was found to be effective against the model tumor nodules even under severe hypoxia. The inherent ability of EtNBS photodynamic therapy to impart cytotoxicity across a wide range of tumoral oxygenation levels indicates its potential to eliminate treatment-resistant cell populations. 相似文献
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28.
M. I. Rajoka Tayyaba Huma A. M. Khalid F. Latif 《World journal of microbiology & biotechnology》2005,21(6-7):869-876
Summary Industrial byproducts namely canola meal, rice bran, sunflower meal, and wheat straw were used as substrates for endo-xylanase
production by Humicola lanuginosemutant TH1 through solid substrate fermentation. The enzyme was secreted extracellularly by both wild and mutant cultures.
Rice bran supported the maximum production of endo-xylanase followed by wheat straw, canola meal and sunflower meal. The highest
activity was achieved after 72 h of culture and the highest yields from the above substrates were 842, 840, 610 and 608 IU
per g substrate consumed respectively. The highest productivity (281 IU flask−1 h−1 corresponding to 5620 l−1 h-1) of endo-xylanase by the mutant of H. lanuginosa was 1.6-fold more than that produced by the parental organism in solid-state fermentation of rice bran at 45 °C. Maximum
specific activity (180 IU mg−1 protein) and substrate consumption rates were significantly more than those reported by previous researchers on Humicola sp. The mutant possessed markedly low accompanying cellulase activity. Thermodynamic studies revealed that the mutant required
significantly lower activation energy for enzyme production and higher for thermal inactivation which signified that the endogenous
metabolic machinery of mutant cells exerted more protection against thermal inactivation during product formation than that
needed by its parental cultures. 相似文献
29.
Background
Polyhydroxyalkanoates are a good substitute for synthetic plastic because they are highly biocompatible, ecofriendly, and biodegradable. Bacteria in freshwater bodies such as rivers, tube wells, and canals are exposed to alternating high and low concentrations of substrates that induce PHA production.Methods
Fresh water samples were collected for isolation of bacterial strains. Screening of PHA in bacterial cells was performed with Sudan and Nile Red staining. Extracted PHA was characterized by FTIR.Results
In this study, nine bacterial isolates were selected for PHA production on the basis of phenotypic screening. Their ability to accumulate PHAs was determined using different monosaccharides and disaccharides. Two bacterial isolates Bacillus cereus T1 (KY746353) and Bacillus cereus R3 (KY746354) produced PHAs. Optimal growth of the bacterial strain (T1) was observed in the presence of glucose, followed by maximum production of PHAs (63% PHAs) during the logarithmic phase of growth. B. cereus R3 (KY746354) accumulated 60% PHAs by dry cell weight.Conclusion
PHA accumulation was relatively less with fructose, but both strains showed increased production (up to 50%) with sucrose. The polymer produced was characterized by Fourier-transform infrared spectroscopy (FTIR), which showed that the compound contains short-chain PHAs.30.
Sadia Saif Arifa Tahir Tayyaba Asim Yongsheng Chen Mujeeb Khan Syed Farooq Adil 《Saudi Journal of Biological Sciences》2019,26(7):1364-1371
In this study, the leaves extract of Cordia myxa, has been used for the first time to synthesize zinc oxide (ZnO) hierarchical microstructures. The solution combustion method was employed as a self-sustaining reaction between zinc nitrate and the leaves extract. The surface properties of leaves mediated ZnO microstructures were determined by UV–Visible spectral analysis, Fourier transform infrared (FT-IR), Cold field emission-scanning electron microscopy (CFE-SEM), Energy dispersive X-ray (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In addition, the effect of the leaves extract concentration on ZnO structures, size and surface properties was also studied. ZnO structures synthesized employing C. myxa were found to be hexagonal, triangular and round in shape which was determined using CFE-SEM. X-ray diffraction (XRD) analysis confirmed the crystalline nature of compounds. Furthermore, C. myxa mediated ZnO microstructures shows good bactericidal activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. 相似文献