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181.
Sumit Kumar Ramovatar Meena R. Paulraj 《Applied biochemistry and biotechnology》2016,180(7):1257-1275
Titanium-dioxide nanoparticles (TNP) are used in various consumable goods. Evidence has demonstrated the cytotoxicity of TNPs, but exact mechanism is yet to be elucidated. The present study has been aimed at finding out the mechanism of TNP-induced toxicity in biological system. Different doses of anatase-TNPs administrated intravenously to Wistar rats for once a week for 1 month and properties of TH cells, macrophages, cytokines secretion, oxidative damage, apoptotic pathway, and hematological and pathological changes were investigated as downstream events of TNP-mediated cytotoxicity. Result suggests that TNPs induce TH1 and TH2 response as measured by immunophenotyping (interferon gamma (IFN-γ) and interleukin (IL)-4) of TH cells, causing induction of M1 (nitric oxide (NO), nitric oxide synthase (iNOS), NF-kappaB (NF-κB), cyclooxygenase-2 (COX-2), IL-1, IL-6, and TNF-α) and M2 (Arg-1, Ym1) macrophages response. At lower dose, TH1 or M1 response counteracted by TH2 or M2 response, resulting in insignificant oxidative damage. However, with increasing dose of TNPs, the M1 response was increased over M2 response resulting in significant tissue damage. The M1-induced inflammatory response was found to cause DNA and chromosomal damage resulting apoptosis induction via upregulation of Bax/Bcl-2 ratio and subsequent loss of mitochondrial membrane potential and cyto c release in splenocytes. The TNP-led inflammatory response also causes damage at different tissue levels. 相似文献
182.
Srihari Pabbaraja Naresh Gantasala Sridhar Ydhyam Hari Krishna Namballa Subhashini Gundeboina Mallikharjuna R. Lambu Sanjeev Meena Dipak Datta 《Tetrahedron letters》2018,59(26):2570-2576
Stereoselective synthesis of twenty (three 12-, five 13- and twelve 14-membered) macrolides and seventeen functionalized 2,6-trans-disubstituted dihydropyran derivatives have been achieved. The key reactions include an Achmatowicz rearrangement, Ferrier-type alkynylation, Yamaguchi macrolactonization and Lindlar’s hydrogenation. Biological screening of the synthesised compounds showed moderate activity against human cancer cell-lines. 相似文献
183.
Malak Azmat Ali Neda Alam Meena Sonbal Ali Sajad Ahmad Dar Afzal Khan G. Murtaza A. Laref 《International journal of quantum chemistry》2020,120(7):e26141
This first principles study explores the structural, electronic, optical, and thermoelectric properties of the CsTmCl3 halide perovskite using density functional theory. The structural and thermoelectric properties are calculated without considering the spin-orbit coupling (SOC), while both the electronic and optical properties are calculated with and without the SOC effect. A comparison of the results obtained with and without SOC reveals that inclusion of the SOC effect reduces the band gap from 1.18 to 0.99 eV due to shifting of the Tm-d states toward the Fermi level. However, direct nature of the band gap remains the same in both the cases. The effect of SOC on the optical properties is, however, only visible in shifting of the third characteristic peak to lower energies. Strong optical absorption in the visible and ultraviolet regions shows effectiveness of CsTmCl3 in the optical devices working in these regions. Moreover, the calculated transport properties reveal CsTmCl3 as a useful thermoelectric material at room temperature. 相似文献
184.
Zebrafish (Danio rerio) is the widely used vertebrate model animal for understanding the complexity of development and disease process. Zebrafish has been also extensively used in understanding the mechanism of regeneration for its extensive capability of regenerating fins and other tissues. We have analyzed the proteome profile of zebrafish caudal fin in its native state based on one-dimensional gel electrophoresis LCMS/MS and two-dimensional gel electrophoresis MS/MS analyses. A total of 417 proteins were identified as zebrafish fin tissue specific, which includes 397 proteins identified based on one-dimensional gel electrophoresis LCMS/MS analysis and 101 proteins identified based on two-dimensional gel electrophoresis MALDI MS/MS. The proteins mapped to the zebrafish fin tissue were shown to be involved in various biological activities related to development, apoptosis, signaling and metabolic process. Focal adhesion, regulation of actin cytoskeleton, cancer-related pathways, mitogen-activated protein kinase signaling, antigen processing and presentation, and proteasome are some of the important pathways associated with the identified proteome data set of the zebrafish fin. 相似文献
185.
Sulphated galactan (SF(A)) containing alpha (alpha), iota (i) and pyruvated alpha-carrageenans (17.6:18.8:25.3 mol %) was extracted and characterized from Sarconema filiforme of Indian waters. The SF(A) and its alkali modified derivative (SF(AM)) were composed of D-galactose, 3, 6-anhydro-D-galactose, 6-O-methylated-D-galactose (64.5:23.0:9.8 and 59.6:29.8:7.6 mol %) respectively. The linkage analysis, physicochemical analysis, infra red and 13C nuclear magnetic resonance spectra of SFA along with linkage analysis of the desulphated derivative (SF(D)) of SFA, reveals that it was a hybrid/combination of alpha/iota carrageenan as well as 3-linked 4',6'-O-(1-carboxyethylidene)-galactose (pyruvated alpha carrageenan) and 6-O-methylated alpha-carrageenan. The flow behavior of SF(A) obtained from rheological measurements suggested strong network formation in presence of 1% aqueous KCl and CaCl2 solutions. 相似文献
186.
Meena K. Cheruvathur Jyothi Abraham T. Dennis Thomas 《Applied biochemistry and biotechnology》2013,169(6):1799-1810
An efficient plant regeneration protocol was established for an endangered ethnomedicinal plant Desmodium gangeticum (Linn.) DC. Morphogenic calli were produced from 96 % of the cultures comprising the immature leaf explants on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (4.0 mg?l?1) in combination with 6-benzylaminopurine (BA; 0.8 mg?l?1). For callus regeneration, various concentrations of BA (1.0–5.0 mg?l?1) or thidiazuron (TDZ; 1.0–5.0 mg?l?1) alone or in combination with indole-3-acetic acid (IAA; 0.2–1.0 mg?l?1) were used. Highest response of shoot regeneration was observed on MS medium fortified with TDZ (4.0 mg?l?1) and IAA (0.5 mg?l?1) combination. Here, 100 % cultures responded with an average number of 22.3 shoots per gram calli. Inclusion of indole-3-butyric acid in half MS medium favored rooting of recovered shoots. Out of 45 rooted plants transferred to soil, 40 survived. Total DNA was extracted from the leaves of the acclimatized plants of D. gangeticum. Analysis of random amplified polymorphic DNA using 13 arbitrary decanucleotide primers showed the genetic homogeneity in all the ten plants regenerated from callus with parental plant, suggesting that shoot regeneration from callus could be used for the true-to-type multiplication of this plant. 相似文献
187.
Mukesh Kumar Atal Jyoti Jain Veena Dhayal Meena Nagar Rakesh Bohra Kuldeep S. Rathore Narendra S. Saxena 《Journal of Sol-Gel Science and Technology》2013,67(1):88-96
A glycol ether modified precursor, [Nb{O(CH2CH2O)2}(OPri)3] (A) was prepared by the reaction of Nb(OPri)5 with O(CH2CH2OH)2 in 1:1 molar ratio in anhydrous benzene. Further reactions of A with a variety of internally functionalized oximes in different molar ratios, yielded heteroleptic complexes of the type, [Nb{O(CH2CH2O)2}(OPri)3?n{ON = C(CH3)(Ar)}n] (1–9) {where Ar = C4H3O-2, n = 1 [1], n = 2 [2], n = 3 [3]; C4H3S-2, n = 1 [4], n = 2 [5], n = 3 [6]; C5H4N-2, n = 1 [7], n = 2 [8], n = 3 [9]}. All the above derivatives have been characterized by elemental analyses, FT-IR, NMR (1H, 13C {1H}) and FAB mass studies. Spectral studies of 1–9 suggest the presence of mono- and bi-dentate mode of oxime moieties, in the solution and in the solid states, respectively. FAB mass studies indicate monomeric nature for 3 and dimeric nature for A. TG curves of A and 6 show their low thermal stability. Soft transformation of A and 3 to pure niobia, a and b, respectively have been carried out by sol–gel technique. The XRD patterns of niobia a and b suggest the formation of nano-size crystallites of average size of 10.8 and 19.5 nm, respectively. The XRD patterns also indicate the formation of monoclinic phase of the niobia in both the cases. Absorption spectra of a and b suggest energy band gaps of 4.95 and 4.39 eV, respectively. 相似文献
188.
K. V. Vimalnath A. Rajeswari Viju Chirayil P. L. Sharad K. C. Jagadeesan P. V. Joshi Meera Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2011,290(1):221-225
64Cu (t1/2 12.7 h) is a versatile radionuclide owing to its unique decay scheme and exhibits three types of decay electron capture (41%),
β− (40%), β+ (19%) that is useful in nuclear medicine applications. Different batches of natural copper oxide (CuO) and 99.9% enriched
63CuO targets were irradiated in research reactors at a neutron flux of 6.6 × 1012 n cm−2 s−1 for duration of 3 days. Irradiated samples dissolved in hydrochloric acid solution were measured in HPGe-MCA system, the
activity of 64Cu, co-produced radionuclide impurities and radionuclide purity was determined. Average specific activity of 254 GBq 64Cu per g Cu and ~348 GBq 64Cu per g Cu was recorded at the end of irradiation from natural and enriched CuO targets, respectively. 相似文献
189.
Abhishek KalerVachan Singh Meena Manpreet SinghBrahmam Pujala Asit K. ChakrabortiUttam Chand Banerjee 《Tetrahedron letters》2011,52(41):5355-5358
A novel biocatalytic method for the enantioselective synthesis of (R)-bromo-3-[4-(2-methoxy-ethyl) phenoxy]-2-propanol [(R)-BMEPP], a precursor for the synthesis of (S)-metoprolol, an anti hypertensive drug is described. We have developed kinetic resolution of rac-BMEPP by transesterification using Candida rugosa lipase and vinyl acetate as the acyl donor affording the product with excellent conversion (49%) and ee (>99%). Various reaction parameters (source of enzyme, reaction media, and concentration of substrate and acylating agent) for the enzymatic kinetic resolution have been reported. 相似文献
190.