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41.
42.
Mehwish Nawaz Haji Muhammad Shoaib Khan Naveed Akhtar Talha Jamshed Rubina Qaiser Hina Shoukat Mehrin Farooq 《Photochemistry and photobiology》2019,95(5):1243-1248
Solar radiations trigger the physiological alteration in skin which progress toward photoaging. Sunscreens are known to be effective against the photodamaging effects of sunlight. The purpose of this study was to evaluate the extent to which aging signs caused by real‐life sunlight exposure could be avoided by comparing various parameters between sun‐exposed and sun‐protected skin using noninvasive probes. Female volunteers (n = 11) after getting their consent were provided with marketed sunscreen product to apply onto their skin for 6 months. Measurements were scheduled every 15 days from the baseline reading for 6 months. Cutometer, Mexameter and Corneometer were used for evaluation of facial skin parameters. Clinical evaluations showed the effects of sunlight exposure on different skin parameters by comparing sun‐protected and unprotected skin, where Gross elasticity (R2), Net elasticity (R5), Viscoelasticity (R6) and Biological elasticity (R7) showed insignificant results, while Hydration, Melanin and Erythema showed significant results. Sun‐exposed skin presented 0.72%, 0.66%, 0.77%, 1.39%, 1.99%, 2.01% and 3.15% changes in R2, R5, R6 and R7, melanin, erythema and hydration, respectively, which were potentially prevented by sunscreen application. Premature aging is inhibited by following photoprotective regimen on routine basis, emphasizing the potential benefit of sunscreen against early aging signs. 相似文献
43.
Xin‐Yi Huang Xia Zhang Dong Pei Jian‐Fei Liu Yuan Gong Haji Akber Aisa Duo‐Long Di 《Journal of separation science》2019,42(11):2080-2088
In this work, a continuous high‐speed countercurrent chromatography method has been developed on the basis of elution‐extrusion mode and this method was successfully applied to the separation of maslinic and oleanolic acid from the extract of olive pulp. In the process of ‘elution’, the sample solution was continuously loaded into the column and the maslinic acid was steadily eluted out in this step while highly retained oleanlic acid always stayed in the column. In the process of ‘extrusion’, the oleanlic acid was pushed out of the column with the stationary phase. In this way, we achieved a large sample loading. A total of 120 mL sample solution (about 89.55% of the column volume) which contains 600 mg olive pulp extract was pumped in the apparatus by a constant‐flow pump and the maslinic and oleanolic acids were largely separated within 120 min. Both of these two compounds presented high yields and high purities (271.6 mg for maslinic acid with 86.7% and 83.9 mg oleanolic acids with 83.4%). 相似文献
44.
We propose a new approach for reconstructing velocity boundary conditions in sharp-inerface immersed boundary (IB) methods based on the moving least squares (MLS) interpolation method. The MLS is employed to not only reconstruct velocity boundary conditions but also to calculate the pressure and velocity gradients in the vicinity of the immersed body, which are required in fluid structure interaction problems to obtain the force exerted by the fluid on the structure. To extend the method to arbitrarily complex geometries with nonconvex shaped boundaries, the visibility method is combined with the MLS method. The performance of the proposed curvilinear IB MLS (CURVIB-MLS) is demonstrated by systematic grid-refinement studies for two- and three-dimensional tests and compared with the standard CURVIB method employing standard wall-normal interpolation for reconstructing boundary conditions. The test problems are flow in a lid-driven cavity with a sphere, uniform flow over a sphere, flow on a NACA0018 airfoil at incidence, and vortex-induced vibration of an elastically-mounted cylinder. We show that the CURVIB-MLS formulation yields a method that is easier to implement in complex geometries and exhibits higher accuracy and rate of convergence relative to the standard CURVIB method. The MLS approach is also shown to dramatically improve the accuracy of calculating the pressure and viscous forces imparted by the flow on the body and improve the overall accuracy of FSI simulations. Finally, the CURVIB-MLS approach is able to qualitatively capture on relatively coarse grids important features of complex separated flows that the standard CURVIB method is able to capture only on finer grids. 相似文献
45.
Iraj Salimikia Rouhollah Heydari Fatemeh Yazdankhah 《Journal of the Iranian Chemical Society》2018,15(7):1593-1601
A solid-phase microextraction fiber was prepared by polyaniline/graphene oxide nanocomposite as sorbent on the surface of a platinized stainless steel wire using electrospinning technique. The nanocomposite structure was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The polyaniline/graphene oxide nanocomposite fiber was used for the determination of nicotine from tobacco samples using headspace solid-phase microextraction method and gas chromatography–flame ionization detection. Influential experimental variables on the extraction efficiency of nicotine, such as extraction time and temperature, humidity and desorption conditions, were evaluated and optimized. Under the optimal experimental conditions? the limit of detection, linear dynamic range, intraday and inter-days precisions were found to be 0.01 μg g?1, 0.05–700 µg g?1 (R2?=?0.996), 6.9 and 8.1%, respectively. Comparison of the polyaniline/graphene oxide nanocomposite sorbent with polyaniline and commercial fibers shows longer durability, larger capacity and higher extraction efficiency. The polyaniline/graphene oxide nanocomposite fiber was successfully applied for the determination of nicotine in tobacco samples. 相似文献
46.
Mohamed E Abdul-Rahman PS Doustjalali SR Chen Y Lim BK Omar SZ Bustam AZ Singh VA Mohd-Taib NA Yip CH Hashim OH 《Electrophoresis》2008,29(12):2645-2650
A 35 kDa glycoprotein whose abundance was previously demonstrated to be enhanced in sera of patients with endometrial adenocarcinoma (n = 12), was isolated from pooled sera of three of the cancer patients using champedak galactose-binding lectin affinity chromatography in the present study. Subjecting it to 2-DE and MS/MS, the glycoprotein was identified as the O-glycosylated fragment of inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4). When compared to control sera (n = 17), expression of the 35 kDa ITIH4 cleavage fragment was demonstrated to be significantly enhanced in sera of patients with breast carcinoma (n = 10), epithelial ovarian carcinoma (n = 10), and germ cell ovarian carcinoma (n = 10) but not in patients with nasopharyngeal carcinoma (n = 13) and osteosarcoma (n = 7). The lectin-based electrophoretic bioanalytical method adopted in the present study may be used to assess the physiological relevance of ITIH4 fragmentation and its correlation with different malignancies, their stages and progression. 相似文献
47.
Ali Naghipour Zahra Haji Ghasemi David Morales-Morales Juan M. Serrano-Becerra Craig M. Jensen 《Polyhedron》2008
The asymmetric PCP pincer ligand [C6H4-1-(CH2PPh2)-3-(CH(CH3)PPh2)] (4) has been synthesized in a facile manner in three simple steps in high yield. Metallation of PCP pincer ligand (4) with [Pd(COD)Cl2] affords complex [PdCl{C6H3-2-(CH2PPh2)-6-(CH(CH3)PPh2)}] (7) in good yield. 相似文献
48.
Solidified floating organic drop microextraction (SFODME) was successfully used as a sample preparation method for graphite furnace atomic absorption spectrometry (GFAAS). 20 μL of 1-undecanol containing dithizone as the chelating agent (2 × 10−4 mol L−1) was transferred to the water samples containing lead ions, and the solution was stirred for the prescribed time. The sample vial was cooled in an ice bath for 5 min. The solidified extract was transferred into a conical vial where it melted immediately, and then 10 μL of it was analyzed by GFAAS.Factors that influence the extraction and complex formation, such as pH, concentration of dithizone, extraction time, sample volume, and ionic strength were optimized. Under the optimized conditions, a good relative standard deviation of ±5.4% at 10 ng L−1 and detection limit of 0.9 ng L−1 were obtained. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments. 相似文献
49.
Tao Wu Rahima Abdulla Yongxin Zhao Yi Yang Jun Chen Haji Akber Aisa 《Chromatographia》2008,67(5-6):467-470
Species of the genus Achillea have been used in traditional folk medicine for centuries. In Europe taxa of the Achillea millefolium group are widely spread, their correct taxonomic differentiation by morphological and anatomical characteristics encounters
some difficulties. Several species of the polyploid A. millefolium group however, can be characterised by their distinct sesquiterpene pattern. Analysis is usually performed by LC using conventional
RP stationary phases. Likewise, it has been proven that non-porous RP stationary phases are an excellent alternative for sensitive
and more rapid separations of plant extracts. In the present work a Kovasil MS-C18 1.5 μm non-porous packing was used with
an acetonitrile-water gradient for the analysis of Achillea flower extracts. Detection and identification of the respective sesquiterpenes has been achieved by diode array detection
and LC coupled APCI+ and ESI+ mass spectrometry. 相似文献
50.
Anham Zafar Dr. Imtiaz-ud-Din Dr. Robert G. Palgrave Dr. Haji Muhammad Dr. Sammer Yousuf Tim Evans 《ChemistryOpen》2023,12(1):e202200229
A series of imidazolium-based symmetrical and asymmetrical dicationic ionic liquids (DcILs) with alkyl spacers of different length and with [FeCl3Br]− as counter ion have been synthesized. The synthesized DcILs are characterized by using FTIR and Raman spectroscopy as well as mass spectrometry, along with single-crystal XRD analysis. Physicochemical properties such as solubility, thermal stability and magnetic susceptibility are also measured. These compounds show low melting points, good solubility in water and organic solvents, thermal stability, and paramagnetism. The products of molar susceptibility and temperature (χmol⋅T) for the synthesized DcILs have been found between 4.05 to 4.79 emu mol−1 K Oe−1 and effective magnetic moment values have also been determined to be compared to that expected from the spin-only approximation. 相似文献