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31.
Dumitru Vieru Corina Fetecau Muhammad Athar Constantin Fetecau 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,60(2):334-343
The unsteady flow of a viscoelastic fluid with the fractional Maxwell model, induced by a constantly accelerating plate between
two side walls perpendicular to the plate, is investigated by means of the integral transforms. Exact solutions for the velocity
field are presented under integral and series forms in terms of the derivatives of generalized Mittag–Leffler functions. The
corresponding solutions for Maxwell fluids are obtained as limiting cases for β → 1. In the absence of the side walls, all
solutions that have been determined reduce to those corresponding to the motion over an infinite plate.
相似文献
32.
Shahwar D Raza MA Shafiq-Ur-Rehman Abbasi MA Atta-Ur-Rahman 《Natural product research》2012,26(12):1087-1093
In the search of new trypsin inhibitors caffeic acid (1), cinnamic acid (2), gallic acid (3) and eugenol (4) from Cinnamomum zeylanicum, ferulic acid (5) from Impatiens bicolor, vanillin (6) from Melia azedarach and catechol (7) from Allium cepa were isolated through bioassay guided fractionation of the plant extracts. IC (50) values of the compounds 1, 2 and 5 were found to be 0.35?±?0.02?mM, 0.96?±?0.05?mM and 1.22?±?0.06?mM, respectively. Lineweaver-Burk and Dixon plots and their secondary replots showed that 1 was non-competitive inhibitor of this enzyme with K(i) value 0.102?±?0.006?mM. 相似文献
33.
Arshad N Janjua NK Khan AY Yaqub A Burkholz T Jacob C 《Natural product communications》2012,7(3):311-315
Three structurally related natural flavonoids (FlOH), quercetin (Q), rutin (R) and morin (M), were investigated by cyclic voltammetry to probe their interactions with hazardous 1,4-dinitrobenzene (1,4-DNB) using a glassy carbon electrode. Scavenging of 1,4-DNB by FlOH was inferred from a positive shift in reduction potential, decrease in anodic peak current, and irreversible electrochemical behavior of 1,4-DNB on increasing the flavonoid concentration. The homogeneous bi-molecular rate constant (k2) was determined using the Nicholson-Shain equation and found to be higher for the dianion. Morin posed a comparatively higher k2 value for its interaction with the 1,4-DNB electrochemical system owing to its more acidic nature and least intramolecular hydrogen bonding. The cyclic voltammetric (CV) results were further supported by HyperchemPM3 quantum mechanical semi-empirical calculations, which point towards E(r)C(i) interactions between flavonoids and 1,4-DNB. The present investigation is biologically significant in terms of natural flavonoidal scavenging activity toward toxins such as dinitroaromatics. 相似文献
34.
Guru R. Valicherla Roshan A. Katekar Shailesh Dadge Mohammed Riyazuddin Anees A. Syed Sandeep K. Singh Athar Husain Muhammad Wahajuddin Jiaur R. Gayen 《Molecules (Basel, Switzerland)》2022,27(2)
PSTi8 is a pancreastatin inhibitory peptide that is effective in the treatment of diabetic models. This study investigates the pharmacokinetic (PK) properties of PSTi8 in Sprague Dawley rats, for the first time. In vitro and in vivo PK studies were performed to evaluate the solubility, stability in plasma and liver microsomes, plasma protein binding, blood–plasma partitioning, bioavailability, dose proportionality, and gender difference in PK. Samples were analyzed using the validated LC-MS/MS method. The solubility of PSTi8 was found to be 9.30 and 25.75 mg/mL in simulated gastric and intestinal fluids, respectively. The protein binding of PSTi8 was estimated as >69% in rat plasma. PSTi8 showed high stability in rat plasma and liver microsomes and the blood–plasma partitioning was >2. The bioavailability of PSTi8 after intraperitoneal and subcutaneous administration was found to be 95.00 ± 12.15 and 78.47 ± 17.72%, respectively, in rats. PSTi8 showed non-linear PK in dose proportionality studies, and has no gender difference in the PK behavior in rats. The high bioavailability of PSTi8 can be due to high water solubility and plasma protein binding, low clearance and volume of distribution. Our in vitro and in vivo findings support the development of PSTi8 as an antidiabetic agent. 相似文献
35.
Md Amjad Beg Shivangi Obaid Afzal Md Sayeed Akhtar Abdulmalik S. A. Altamimi Afzal Hussain Md Ali Imam Mohammad Naiyaz Ahmad Sidharth Chopra Fareeda Athar 《Molecules (Basel, Switzerland)》2022,27(14)
The emergence of drug resistance and the limited number of approved antitubercular drugs prompted identification and development of new antitubercular compounds to cure Tuberculosis (TB). In this work, an attempt was made to identify potential natural compounds that target mycobacterial proteins. Three plant extracts (A. aspera, C. gigantea and C. procera) were investigated. The ethyl acetate fraction of the aerial part of A. aspera and the flower ash of C. gigantea were found to be effective against M. tuberculosis H37Rv. Furthermore, the GC-MS analysis of the plant fractions confirmed the presence of active compounds in the extracts. The Mycobacterium target proteins, i.e., available PDB dataset proteins and proteins classified in virulence, detoxification, and adaptation, were investigated. A total of ten target proteins were shortlisted for further study, identified as follows: BpoC, RipA, MazF4, RipD, TB15.3, VapC15, VapC20, VapC21, TB31.7, and MazF9. Molecular docking studies showed that β-amyrin interacted with most of these proteins and its highest binding affinity was observed with Mycobacterium Rv1636 (TB15.3) protein. The stability of the protein-ligand complex was assessed by molecular dynamic simulation, which confirmed that β-amyrin most firmly interacted with Rv1636 protein. Rv1636 is a universal stress protein, which regulates Mycobacterium growth in different stress conditions and, thus, targeting Rv1636 makes M. tuberculosis vulnerable to host-derived stress conditions. 相似文献
36.
T. Rüffer H. Lang S. Nawaz A. A. Isab S. Ahmad M. M. Athar 《Journal of Structural Chemistry》2011,52(5):1025-1029
A mixed-ligand silver(I) complex of triphenylphosphine and N,N′-dibutylthiourea (Dbtu), [Ag(Ph3P)2(Dbtu)2]NO3, is prepared and its structure in the solid state is determined by X-ray crystallography. X-ray structure of this complex
shows that it is mononuclear with the silver atom coordinated by two PPh3 and two dibutylthiourea ligands adopting a distorted tetrahedral geometry. The crystal structure shows the formation of 1-D
chains through intermolecular hydrogen bonding interactions between N-H of Dbtu and nitrate ions. The new complex is also
characterized by IR and NMR (1H and 31P) spectroscopy. The spectroscopic data are discussed in terms of the nature of bonding. A similar mixedligand complex is
also prepared for tetramethylthiourea (Tmtu), but the structure of the resulting compound shows that it is a bis(phosphine)
complex, [Ag(PPh3)2NO3] rather than a mixed-ligand complex. 相似文献
37.
The kinetics of electron transfer between chromium(VI) and H3PO3, yielding chromium(III), have been investigated in HClO4
and H2SO4 media by visible spectrophotometry. The rate of reaction increased with increasing [H2SO4] and [HClO4]. A rate law
based on ester formation preceding the electron transfer has been established and a possible mechanism has been proposed.
The mechanism and the derived rate law are consistent with the observed kinetics.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
38.
Abdellatif Bouazzaoui Ahmed A. H. Abdellatif Faisal A. Al-Allaf Neda M. Bogari Mohiuddin M. Taher Mohammad Athar Thomas Schubert Turki M. Habeebullah Sameer H. Qari 《Molecules (Basel, Switzerland)》2021,26(14)
Systemic steroids are used to treat acute graft-versus-host disease (aGVHD) caused by allogenic bone marrow transplantation (allo-BMT); however, their prolonged use results in complications. Hence, new agents for treating aGVHD are required. Recently, a new compound A (CpdA), with anti-inflammatory activity and reduced side effects compared to steroids, has been identified. Here, we aimed to determine whether CpdA can improve the outcome of aGVHD when administered after transplantation in a mouse model (C57BL/6 in B6D2F1). After conditioning with 9Gy total body irradiation, mice were infused with bone marrow (BM) cells and splenocytes from either syngeneic (B6D2F1) or allogeneic (C57BL/6) donors. The animals were subsequently treated (3 days/week) with 7.5 mg/kg CpdA from day +15 to day +28; the controls received 0.9% NaCl. Thereafter, the incidence and severity of aGVHD in aGVHD target organs were analyzed. Survival and clinical scores did not differ significantly; however, CpdA-treated animals showed high cell infiltration in the target organs. In bulk mixed lymphocyte reactions, CpdA treatment reduced the cell proliferation and expression of inflammatory cytokines and chemokines compared to controls, whereas levels of TNF, IL-23, chemokines, and chemokine receptors increased. CpdA significantly reduced proliferation in vitro but increased T cell infiltration in target organs. 相似文献
39.
Yasmin Khan Md Tanwir Akhtar Romana Shehl Athar Ali Khan 《Journal of Applied Analysis & Computation》2015,5(1):38-51
Data generated in forestry biometrics are not normal in statistical sense as they rarely follow the normal regression model. Hence, there is a need to develop models and methods in forest biometric applications for non-normal models. Due to generality of Bayesian methods it can be implemented in the situations when Gaussian regression models do not fit the data. Data on diameter at breast height (dbh), which is a very important characteristic in forestry has been fitted to Weibull and gamma models in Bayesian paradigm and comparisons have also been made with its classical counterpart. It may be noted that MCMC simulation tools are used in this study. An attempt has been made to apply Bayesian simulation tools using \textbf{R} software. 相似文献
40.
Zahoor Qadir Samra Sadaf Shabir Zainab Rehmat Mariam Zaman Aqsa Nazir Nadia Dar Muhammad Amin Athar 《Applied biochemistry and biotechnology》2010,162(3):671-686
Human serum paraoxonase 1 (PON1) is known as an antioxidant and is also involved in the detoxification of many compounds.
In this study, a novel purification strategy was employed to purify the PON1 by using cholesterol-conjugated magnetic nanoparticles.
Magnetic nanoparticles were synthesized and conjugated with cholesterol through diazotized p-aminohippuric acid. In Fourier transform infrared spectrum of cholesterol-p-aminohippuric acid-Fe3O4 nanoparticles, the appearance of peaks at 3,358.3, 1,645 cm−1, and at 2,334.9 cm−1 confirmed the conjugation. The molecular weight of purified PON1 was nearly 45 kDa on sodium dodecyl sulfate (SDS)–polyacrylamide
gel electrophoresis (PAGE), and isoelectric point was 5.3. The specific activity was 438 U mg−1 protein, and the purification fold was 515 with 73% yield. The K
m values were 1.3 and 0.74 mM with paraoxon and phenyl acetate, respectively. Western blot of 2D-PAGE confirmed the homogeneity
and stability of the enzyme. Mg+2, Mn+2, glycerol, (NH4)2SO4, PEG 6000, Triton X-100, and phenylmethylsulfonyl fluoride did not show any effect on activity. Pb+2, Co+2, Zn2+, ethanol, β-mercaptoethanol, and acetone reduced the activity while Ni2+, Cd2+, Cu2+, iodoacetic acid, SDS, dimethylformamide, DMSO inhibited the activity. In vitro enzyme activity was slightly reduced by acetyl
salicylic and acetaminophen and reduced 50% with amino glycosides and ampicillin antibiotics at concentrations of 0.6 and
30 mg ml−1, respectively. This is the first report for the synthesis of cholesterol-conjugated magnetic nanoparticles for simple purification
of PON1 enzyme. 相似文献