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61.
Densities and sound velocities for aqueous monoethanolamine (MEA) system are reported over the entire composition range at different temperatures (298.15, 303.15, 313.15 and 318.15 K). These experimental data have been further used in calculating the excess molar volume, partial molar volumes, isobaric thermal expansion coefficients and the deviation in isentropic compressibility. The excess molar volumes data were fitted to the Redlich–Kister polynomial equation to obtain their coefficients and standard deviations. The partial molar volume at infinite dilution of both water in MEA and MEA in water and have been determined using two different methods. Knowledge of the above properties of these mixtures is a basis for understanding some of the molecular interactions in these systems. From the analysis of the results, the type of interactions between the MEA and water is discussed in terms of the number and size of the alkyl groups attached to the nitrogen atom of MEA.  相似文献   
62.
Sugar palm fiber (SPF) is one of the prospective fibers used to reinforce polymer composites. The aim of this study is to evaluate the physicochemical, thermal, and morphological properties of SPF after alkali and sea water treatments. The chemical constituents group and thermal stability of the SPF were determined using scanning electronic microscopy (SEM) along with energy dispersive X-ray spectroscopy and thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy was carried out to detect the presence of functional groups in untreated and treated SPF. The SEM images after both treatments showed that the external surface of the fiber became clean as a result. However, the sea water treatment affected the fiber properties physically, while the alkali treatment affected it both physically and chemically by dissolving the hemicellulose in the fiber. The TGA results showed that untreated fiber is significantly more stable than treated fiber. In conclusion, the results show that the fiber surface treatment significantly affected the characterization of the fiber.  相似文献   
63.
Natural polymers have been extensively utilized in the past decades due to their outstanding features. Among these natural excipients, protein‐based polymers have superb features owing to their high drug binding capacity and biodegradability. Whey protein is a versatile protein‐based vehicle for drug delivery systems. It has been shown to be nontoxic, biocompatible, and biodegradable. Therefore, it has been considered as an ideal biomaterial for the design of advanced drug delivery systems. Protein‐based cargo acts as synthetic polymers counterpart for innovative delivery systems. The current review is mainly focused on application of whey proteins as an emerging carrier in drug delivery systems, achieved during the past.  相似文献   
64.
65.
Applied Biochemistry and Biotechnology - Prostate cancer is one of the major causes of cancer-related deaths in men and there is a growing interest in identifying natural compounds for its...  相似文献   
66.
7β-(3-Ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a sesquiterpenoid obtained from a natural source has proved to be effective in minimizing various side effects associated with opioids and nonsteroidal anti-inflammatory drugs. The current study focused on investigating the effects of ECN on neuropathic pain induced by partial sciatic nerve ligation (PSNL) by mainly focusing on oxidative stress, inflammatory and apoptotic proteins expression in mice. ECN (1 and 10 mg/kg, i.p.), was administered once daily for 11 days, starting from the third day after surgery. ECN post-treatment was found to reduce hyperalgesia and allodynia in a dose-dependent manner. ECN remarkably reversed the histopathological abnormalities associated with oxidative stress, apoptosis and inflammation. Furthermore, ECN prevented the suppression of antioxidants (glutathione, glutathione-S-transferase, catalase, superoxide dismutase, NF-E2-related factor-2 (Nrf2), hemeoxygenase-1 and NAD(P)H: quinone oxidoreductase) by PSNL. Moreover, pro-inflammatory cytokines (tumor necrotic factor-alpha, interleukin 1 beta, interleukin 6, cyclooxygenase-2 and inducible nitric oxide synthase) expression was reduced by ECN administration. Treatment with ECN was successful in reducing the caspase-3 level consistent with the observed modulation of pro-apoptotic proteins. Additionally, ECN showed a protective effect on the lipid content of myelin sheath as evident from FTIR spectroscopy which showed the shift of lipid component bands to higher values. Thus, the anti-neuropathic potential of ECN might be due to the inhibition of oxidative stress, inflammatory mediators and pro-apoptotic proteins.  相似文献   
67.
Sonogashira cross coupling is a well-known reaction for the formation of carbon–carbon bond. It involves the coupling of aryl halides with terminal alkynes to synthesize versatile functionalized alkyne scaffolds having diverse applications. Many of the natural products and important pharmaceutical drugs can be obtained through this reaction. In this regard, hectic progress has been put by the synthetic chemists to make this cross coupling more effective. This review article discloses mild and environmental friendly reaction conditions of Sonogashira cross coupling developed during 2013–2018.  相似文献   
68.
Non-linear rheology of a mixture of two viscoelastic immiscible liquids undergoing high deformation flow was considered. Using Grmela's formalism (Grmela 1986, 1989, 1993a, b) and the coarse grained picture given by Onuki (1987) and Doi and Ohta (1991), we have derived a set of highly non-linear time-dependent transport equations that take into account a direct coupling between the rheology and morphology. Breakup, coalescence, and the high deformation of the interface were considered. Models of Doi and Ohta (1991), Lee and Park (1994), and Grmela et al. (1998) are recovered as special cases. The parameters of?the model were given a physical meaning in both shear and elongational flows and the predictions of the model were ¶compared to the predictions of the previous models on the basis of experimental results obtained on two model?blends PDM/PB polydimethylsiloxane/poly(1-butene) and PP/PS polypropylene/polystyrene blends.  相似文献   
69.
In the present study, five 4-aminophenol derivatives (4-chloro-2-(((4-hydroxyphenyl)imino)methyl)phenol(S-1), 4-((4-(dimethylamino)benzylidene)amino)phenol(S-2), 4-((3-nitrobenzylidene)amino)phenol(S-3), 4-((thiophen-2-ylmethylene)amino)phenol(S-4) and 4-(((E)-3-phenylallylidene)amino)phenol(S-5)) were synthesized and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analyses. The synthesized compounds were tested for their antimicrobial (Gram-positive and Gram-negative bacteria and Saccharomyces cervesea fungus) and antidiabetic (α-amylase and α-glucosidase inhibitory) activities. All the compounds showed broad-spectrum activities against the Staphylococcus aureus (ATCC 6538), Micrococcus luteus (ATCC 4698), Staphylococcus epidermidis (ATCC 12228), Bacillus subtilis sub. sp spizizenii (ATCC 6633), Bordetella bronchiseptica (ATCC 4617) and Saccharomyces cerevisiae (ATCC 9763) strains. The newly synthesized compounds showed a significant inhibition of amylase (93.2%) and glucosidase (73.7%) in a concentration-dependent manner. Interaction studies of Human DNA with the synthesized Schiff bases were also performed. The spectral bands of S-1, S-2, S-3 and S-5 all showed hyperchromism, whereas the spectral band of S-4 showed a hypochromic effect. Moreover, the spectral bands of the S-2, S-3 and S-4 compounds were also found to exhibit a bathochromic shift (red shift). The present studies delineate broad-spectrum antimicrobial and antidiabetic activities of the synthesized compounds. Additionally, DNA interaction studies highlight the potential of synthetic compounds as anticancer agents. The DNA interaction studies, as well as the antidiabetic activities articulated by the molecular docking methods, showed the promising aspects of synthetic compounds.  相似文献   
70.
Every year, tuberculosis affects the lungs of millions of people and rifampicin is the commonly used medicine for its treatment due to its antibiotic nature. The frequent use of rifampicin may lead to its increased concentration in the water resources. This research work is focused on the cloud point extraction (CPE) procedure for the preconcentration of rifampicin prior to its determination in water. The UV/vis spectrophotometric method was adapted for the measurement of rifampicin content after the phase separation. Triton-X 100 was used as the nonionic surfactant which contains hydrophilic polyethylene chain feasible for the extraction of analyte. Various analytical parameters that can affect the extraction efficacy were optimized to achieve linearity of the proposed method in the concentration range of 3.54–81.41 mgL–1. The Limit of detection and quantification were 1.261 and 4.212 mgL1, respectively. The Preconcentration factor was 40 with relative standard deviation (%RSD) of 2.504%. The standard addition methodology was adopted for the validation of this procedure and effectively applied for the determination of rifampicin in real wastewater samples.  相似文献   
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