排序方式: 共有110条查询结果,搜索用时 15 毫秒
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P. Sarita G. J. Naga Raju M. Ravi Kumar A. S. Pradeep S. Bhuloka Reddy 《Journal of Radioanalytical and Nuclear Chemistry》2013,297(3):431-436
Trace elemental imbalance in human beings is postulated to exert action, directly or indirectly, on the carcinogenic process. The objective of this study was to evaluate the levels of trace elements in blood serum samples of lung cancer patients and analyze their alteration with respect to healthy controls. Particle induced X-ray emission (PIXE), a well established method for elemental analysis, was used to identify and quantify trace elements in the blood serum samples of the studied groups. The PIXE measurements were carried out using 2.5 MeV collimated proton beam from the 3 MV Tandem Pelletron Accelerator at Ion Beam Laboratory, Institute of Physics, Bhubaneswar, India. The serum of the cancerous group displayed increased concentrations of Ti, Ni, and Cu but lowered concentrations of V, Cr, Mn, Fe, Co, Zn, and Se. Statistically significant differences were found for serum Cr (p < 0.01), Fe (p < 0.0005), Ni (p < 0.05), Cu (p < 0.00005), and Zn (p < 0.0005) between the two studied groups. The copper to zinc ratio for the lung cancer group was 2.24 ± 0.39, which was almost three times the value for normal subjects (0.77 ± 0.14). The observed alterations are discussed with respect to the possible mechanisms by which these elements might influence the carcinogenic process. Significant reduction in mortality from lung cancer can be achieved by advances in early diagnosis and implementation of multidisciplinary treatment programmes leading to improvement of survivorship and better quality of life. It is expected that similar studies from all corners of the world would ultimately lead to the development of novel therapeutic agents to treat lung cancer. 相似文献
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Sarita C. Rabelo Rubens Maciel Filho Aline C. Costa 《Applied biochemistry and biotechnology》2013,169(5):1696-1712
Sugarcane bagasse was subjected to lime (calcium hydroxide) pretreatment and enzymatic hydrolysis for second-generation ethanol production. A central composite factorial design was performed to determine the best combination of pretreatment time, temperature, and lime loading, as well as to evaluate the influence of enzymatic loadings on hydrolysis conversion. The influence of increasing solids loading in the pretreatment and enzymatic hydrolysis stages was also determined. The hydrolysate was fermented using Saccharomyces cerevisiae in batch and continuous mode. In the continuous fermentation, the hydrolysates were concentrated with molasses. Lime pretreatment significantly increased the enzymatic digestibility of sugarcane bagasse without the need for prior particle size reduction. In the optimal pretreatment conditions (90 h, 90 °C, 0.47 g?lime/g bagasse) and industrially realistic conditions of hydrolysis (12.7 FPU/g of cellulase and 7.3 CBU/g of β-glucosidase), 139.6 kg?lignin/ton raw bagasse and 126.0 kg hemicellulose in the pretreatment liquor per ton raw bagasse were obtained. The hydrolysate from lime pretreated sugarcane bagasse presented low amounts of inhibitors, leading to ethanol yield of 164.1 kg?ethanol/ton raw bagasse. 相似文献
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A Comparison Between Lime and Alkaline Hydrogen Peroxide Pretreatments of Sugarcane Bagasse for Ethanol Production 总被引:1,自引:0,他引:1
Pretreatment procedures of sugarcane bagasse with lime (calcium hydroxide) or alkaline hydrogen peroxide were evaluated and
compared. Analyses were performed using 23 factorial designs, with pretreatment time, temperature, and lime loading and hydrogen peroxide concentration as factors.
The responses evaluated were the yield of total reducing sugars (TRS) and glucose released from pretreated bagasse after enzymatic
hydrolysis. Experiments were performed using the bagasse, as it comes from an alcohol/sugar factory and bagasse, in the size,
range from 0.248 to 1.397 mm (12–60 mesh). The results show that, when hexoses and pentoses are of interest, lime should be
the pretreatment agent chosen, as high TRS yields are obtained for non-screened bagasse using 0.40 g lime/g dry biomass at
70 °C for 36 h. When the product of interest is glucose, the best results were obtained with lime pretreatment of screened
bagasse. However, the results for alkaline peroxide and lime pretreatments of non-screened bagasse are not very different. 相似文献
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Natural Product‐Mimetic Scaffolds with Privileged Heterocyclic Systems: Design,Synthesis, and Evaluation of Antioxidant Activity of Quinazoquinobenzothiazinones 下载免费PDF全文
Kshitija Sharma Sarita Khandelwal R. M. Samarth Mahendra Kumar 《Journal of heterocyclic chemistry》2016,53(1):220-228
Structurally diverse quinazolinoquinolinobenzothiazinones based on rutaecarpine structural framework with hybrid structural features of three medicinally privileged heterocyclic systems has been synthesized as natural product‐mimetic scaffolds involving the use of multi‐step reaction sequences. The synthesized quinazolinoquinolinobenzothiazinones have been evaluated for their antioxidant and radical scavenging activities. 相似文献
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Dutta P Ray N Roy S Dasgupta AK Bouloussa O Sarkar A 《Organic & biomolecular chemistry》2011,9(14):5123-5128
A cross-metathesis reaction between an alkene terminated self-assembled monolayer (SAM) on glass/Si wafer and an alkene tethered Fischer carbene complex yielded a functionalized surface. Rapid aminolysis of the Fischer carbene moieties permit efficient anchoring of amine containing molecules on such a surface. Attachment of 1-pyrenemethylamine was thus monitored by ATR-IR spectroscopy and fluorescence microscopy. Similarly, BSA and lysozyme were individually grafted to such Fischer carbene modified surfaces using their pendant lysine residues. It has been demonstrated that the anchored lysozyme retains its bactericidal property. 相似文献
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Advanced polymeric materials undoubtedly constitute one of the most promising classes of new materials due to their intriguing electronic, optical, and redox properties. The incredible progress in this area has been driven by the development of novel synthetic procedures owing to the emergence of nanotechnology and by the large array of applications. In particular, hybridization of polymeric materials with nanomaterials has allowed the production of promising functional materials with tailored properties and functionalities for targeted biomedical applications. Consequently, sufficient researchers have carried out imperative studies on these advanced polymeric materials over the last decade. Beyond scientific and fundamental interest, such advanced materials are conspicuous from technological perspectives as well. In this review, we accentuate the proliferation of advanced polymeric materials in diverse biomedical applications. 相似文献
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Rodrigo S. Corrêa Sarita A. Santana Rogrio Salloum Rosalice M. Silva Antnio C. Doriguetto 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):o115-o117
A planar conformation of 1,3‐thiazolidine‐2‐thione (TZDTH), C3H5NS2, was crystallized for the first time. The new triclinic polymorph (P) obtained was compared in terms of its intra‐ and intermolecular geometry with three previous reports of a monoclinic polymorph (P21/n). The packing is based on centrosymmetric dimers of TZDTH, linked by N—H⋯S hydrogen bonds. 相似文献
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Mechanistic studies of the enolization of 2-methylcyclohexanone mediated by lithium hexamethyldisilazide (LiHMDS; TMS(2)NLi) solvated by hindered dialkyl ethers (ROR') are described. Rate studies using in situ IR spectroscopy show that enolizations in the presence of i-Pr(2)O, 2,2,5,5-tetramethyltetrahydrofuran, and cineole proceed via dimer-based transition structures [(TMS(2)NLi)(2)(ROR')(ketone)]. Comparing the relative solvation energies and the corresponding solvent-dependent activation energies shows that the highly substituted ethers accelerate the enolizations by sterically destabilizing the reactants and stabilizing the transition structures. Comparisons of hindered dialkyl ethers with their isostructural dialkylamines reveal that the considerably higher rates elicited by the amines derive from an analogous relative destabilization of the reactants and relative stabilization of the transition structures. 相似文献