130 research outputs found
Multifunctional mesoporous and nanostructured catalysts: exploring novel synthetic methods, properties and applications
No full textNovel multifunctional mesoporous and nanostructured catalysts containing two or more different types of judiciously chosen functional / catalytic groups were developed and their unique and cooperative catalytic activities in various useful organic reactions were explored. First, mesoporous silica material containing tertiary amine/silanol groups was synthesized by simple postgrafting synthetic method. The material was found to exhibit efficient cooperative acid/base bifunctional catalytic activity towards Michael addition reactions between trans-β-nitrostyrene and various active methylene compounds such as malononitrile, acetylacetone and dimethylmalonate. Besides serving as a solid base catalyst, such organoamine-functionalized mesoporous silica materials can be utilized as effective support materials for catalytically active organometallic complexes. This was demonstrated by immobilizing ethylenediamine onto mesoporous silica via postgrafting synthetic method and then complexing Fe(III) onto the supported ethylenediamine groups. This yielded a bifunctional Fe(III)/silanol-based heterogeneous catalyst that showed efficient catalytic activity towards epoxide ring opening reactions. Next, the potential of these types of organic-functionalized mesoporous silicas for immobilization of metallic nanoparticle catalysts was investigated. Specifically, mercaptopropyl-functionalized mesoporous silica was synthesized and the material was then supported with ultrasmall Aun nanoclusters. The catalytic properties of the resulting materials in styrene oxidation were studied. Furthermore, the effect of the removal of the thiol groups from around the surfaces of the gold nanoclusters on catalytic activities of the mesoporous silica-supported nanoparticles was investigated. As mesoporous silica have some limitations of crowding in their pores and poor mass transport for reactants when they are functionalized with larger groups such as nanoparticles, a new strategy was developed, where such catalytic groups were immobilized on the outer surface of silica microspheres. These supported nanoparticle catalytic groups on the silica nanospheres were further coated with a porous silica shell in order to overcome their possible aggregation, sintering and loss of catalytic activities. The resulting nanomaterials, dubbed produced SiO2-Au-pSiO2 core-shell-shell microspheres, were then used as efficient and recyclable nanocatalysts for styrene epoxidation. This strategy was further extended to core-shell-shell microspheres containing the metal (e.g., Pd) nanoparticles within G4 PAMAM dendrimers that are supported on silica nanosphere cores and coated by nanoporous silica shells. These nanomaterials, denoted as SiO2-Pd/PAMAM-pSiO2 core-shell-shell microspheres, were shown to serve not only as efficient and recyclable catalysts but also as selective catalysts for specific functional groups in hydrogenation reaction of various substrates.Ph. D.Includes bibliographical referencesby Sayantani Da
Development of Bio-FET sensor for the detection of Boron
No full textMSc Biotechnology ThesisBoron is an essential micronutrient for the plants and plays a major role in development of animals and human. The rise in industry of glass, ceramic, cosmetic, soaps, and detergent caused emission of larger amount of boron into the atmosphere, soil, and water. On exposure to this excess boron, the living beings are suffering from serious health hazards and this is also causing death of the plants. Several methods have been implemented to determine their concentration such as spectrophotometric methods, but these methods suffer as they’re not very sensitive and precise, require large sample volume, sophisticated instrument, and are expensive. This lead to develop a sensor that will overcome the drawbacks of earlier method of boron determination. Bio-FET sensor was then designed on SILVACO TCAD tool based on the doping concentration of boric acid into different biopolymers to check for small change in dielectric and large change in threshold voltage of the sample solution.Department of Biotechnology, TIET, Patial
Petrological and geochemical characteristics of gabbros drilled at IODP site 1415 : Evidence for an enriched mantle source beneath the East Pacific Rise.
No full textIODP 地点1415で掘削されたはんれい岩の岩石学的および地球化学的特徴 : 東太平洋海嶺下の肥沃なマントルソースの証拠
No full textODP Expedition 345 aimed to drill lower crust gabbros at Hess deep rift (East Pacific Rise, 2°14’N-101°30’W), which is located near the junction between EPR and the Cocos, Nazca and Ridge. Lower crust oceanic gabbros were sampled on a about 200 m wide bench located on the intrarift southern slope between 4675 and 4850 m below sea level, and total of 11 holes (1415A to P) were drilled, among which two reached a depth over 110 m below seafloor (Holes 1415J and 1415P; see IODP Expedition 345 Scientific Report, 2013). Primitive troctolites and olivine-rich gabbros were the main lithologies recovered from these two holes. Shipboard data showed a whole rock chemistry with a high Mg# in concordance with their primitive nature. In a MOR system, olivine is a typical primitive mineral and orthoyroxene (Opx) usually appear late in the crystallization sequence, when the magma already reached a significant degree of differentiation. In spite Opx is not expected in any primitive lithology, this mineral is commonly present in Hole 1415P gabbros and associated with olivine. This curious association of cumulate Opx with olivine and other primitive minerals was also observed at a lower extent in some gabbros from IODP Hole 1256D, in the upper Hess Deep crustal section (ODP Hole 894G)We studied about 70 samples from Holes J and P, and 15 samples from the upper crust (ODP Hole 894G and rubbles from IODP site 1415) for their petrography and mineral chemistry. All samples are olivine gabbros and show an overall cumulate texture with ophitic to subophitic domain consisting of large clinopyroxenes enclosing plagioclase and olivine chadacrysts. Olivine is subhedral to sub-rounded and plagioclase appear as subhedral laths. Beside the main constituent phases in Olivine gabbros, a relatively high content of orthopyroxenes may be observed (≥ 5%). Three types of Opx textures may be distinguished in Opx-bearing olivine gabbros (1) recrystallized corona around olivine, (2) exsolution within clinopyroxene and (3) large prismatic or poikilitic grains. The third type is the most common and overall texture points to a crystallization order starting with olivine and plagioclase, and finishing with clinopyroxene and then orthopyroxene.In the upper crust, samples are less rich in olivine and mineral chemistry points to relatively differentiated characteristics compatible with a formation by fractional crystallization from a magma a MORB melt having undergone a certain degree of differentiation. In the lower crust, mineral chemistry show systematically primitive characteristics with high olivine forsterite content, clinopyroxene and orthopyroxene Mg# for all samples. Hole J gabbros show a clear evolution from the bottom to the top, with decreasing Mg# and increasing minor and trace elements contents in mafic minerals. Processes dominated by fractional crystallization can explain the genesis of the Hole 1415J gabbroic column. On the other hand, the narrow down hole variation ranges for Mg# in Opx (84-86%), Cpx (86-92%) and olivine (85-90%) in Hole 1415P, together with a a large scatter in minor and trace elements (Ti, Al, Cr, Ni, Mn, Yb, Cs, Zr, etc.), in Cpx and Opx suggests that, at a global scale, the gabbro column were only affected by a moderate degree of differentiation and melt/rock reaction leading to Mg/Fe ratio buffering played a major role in the formation process. However the relatively low Mg# (below 88%) values show that the reactant was rich in relatively differentiated mafic minerals with a general Mg# lower than in mantle rocks. Chemical zoning observed in the ophitic clinopyroxenes show that the crystallization process might be locally dominated by small-scale differentiation.Calculated compositions for liquids in equilibrium with Cpx and plagioclase, using both minor and trace elements are consistently between the EPR MORB and the Galapagos basalts chemical domains. In contrast, the melt in equilibrium with Opx in Hole P plot out of the MORB and OIB domain and is significantly richer in Ti. Mg# calculations on all the ferro-magnesian minerals show that Opx and olivine are in equilibrium while Cpx has a higher Mg# than the calculated Cpx in equilibrium with Opx These demonstrate that a two phases magmatic process occurred, in association with the melting of a enriched mantle source (similar to that producing enriched basalts at the Galapagos hotspot) to generate EPR lower gabbros: 1) Crystallization of a Mg/Fe ration buffered mush. The melt in this mush originated from an enriched mantle source, melts injected in the mush got buffered by a probable melt-rock reaction process occurring in the underlying troctolites. A certain degree of differentiation may occur in the mantle and troctolites, leading to stronger enrichment but the buffering event erased any chemical evidence of differentiation. The appearances of Opx at an early stage in the crystallization sequence suggest a Si-rich source compatible with pyroxenite melting. 2) Local differentiation leading to the crystallization of zoned Cpx in concurrence with Opx precipitation.MORB melts crystallizing in Hole 1415J are expelled out from the lower crust to the melt lens located at the top of the gabbro section. Enriched melts crystallizing in Hole 1415P are not observed in the basalts formed at the top of the section, this show that some melts produced in the mantle were not extracted from the basaltic mush to the melt lens. They entirely crystallized in the lower crust and are not expressed at the surface. Our study showed the limitation of the basaltic glasses method, sued up to now in order to calculate a general MORB or enriched mantle source
Dissecting the liver tumour micro-environment: cell- and subcellular-specific characterisation of N-glycosylated basigin
No full textBasigin (CD147), an N-glycosylated transmembrane protein occurring in four potential isoforms, isexpressed on surfaces of immune and cancer cells forming the heterogeneous tumour microenvironment.Basigin display pro- and anti-tumorigenic functions by interacting with multiplebinding partners; interactions that are modulated by glycosylation. However, the molecular featuresof basigin and the N-glycosylation of the cells of the tumour micro-environment remainundescribed. This thesis aimed to characterise the low abundance basigin from primary neutrophilsand HepG2 cancer cells as representative immune and cancer components of the liver tumourmicro-environment. Multiple enrichment and isolation strategies including immunoprecipitation,cell surface protein capture and plasma membrane separation were performed in conjunction withwestern blotting and advanced tandem mass spectrometry. For the first time, human basiginisoform-2 was successfully characterised from both neutrophils and HepG2 by extensive mappingof the polypeptide chain. Cell- and subcellular-specific N-glycomics revealed paucimannose-rich Nglycosylationof neutrophil plasma membranes and dominant high mannose type N-glycans ofHepG2 microsomes. In conclusion, glycobiology and powerful glyco-analytical technologies werebrought together to reveal novel molecular features of a key cancer and immune glycoprotein.These findings contribute to our understanding of the structure and function of basigin andsubcellular-specific N-glycosylation in the tumour micro-environment. (200 words
TO WHAT EXTENT DO COUPLES’ PRE-MARITAL COMMUNICATIONS AFFECT THEIR POST-MARITAL FERTILITY BEHAVIOUR IN INDIA?
No full textSummaryReproduction in India is mainly confined to within marriage. The fertility preferences of spouses will not necessarily be the same, but discussion between couples creates scope for understanding between spouses after marriage. Knowing each other’s opinions facilitates decision-making on sensitive matters such as contraception use and desired family size. This study used data from the India Human Development Survey-II (2011–12), and was based on a sample of 31,276 currently married women. The aim was to understand the role of pre-marital communication, studied through the choosing of husbands, mutual communication before marriage and duration of time spouses knew each other before marriage on the fertility preferences of couples post-marriage. These preferences included contraception use, who has most say on the number of children and the gap between desired and actual number of offspring. The results showed that wives who knew their husbands or who had any kind of communication with them before marriage had a greater chance of being involved in fertility decisions. However, most fertility decisions were found to be male-driven. Wives who knew their husbands for more than a month before marriage took more decisions on number of children (27%) than those who only knew their husbands from the day of their wedding (20%). Wives were less likely to have more children/sons/daughters than desired if they had some communication with their husbands before marriage. A better understanding of fertility preferences between spouses might help to curb unwanted births through delaying or limiting births by contraception use. Families in India could encourage couples to interact before marriage so they can make collective decisions on contraception use and/or the number of children they have.</jats:p
IMPACT OF SEX COMPOSITION OF LIVING CHILDREN AND COUPLES’ AGREEMENT ON SUBSEQUENT FERTILITY IN INDIA
No full textSummaryThe desire for children could be considered a reliable predictor of subsequent fertility. At the same time, the sex composition of surviving children, along with other demographic and socioeconomic factors, may affect a couple’s fertility desire and, therefore, their subsequent fertility. This study examined the impact of the sex composition of living children and a couple’s agreement on fertility desire on their subsequent fertility in India using data came from two rounds of nationally representative surveys: the India Human Development Survey (IHDS)-I (2004–05) and IHDS-II (2011–12). To understand which factors affect the chances of an additional pregnancy or childbirth, a random effects logistic regression model was applied to the panel data. It was found that the fertility desires of both marital partners were important in determining the chances of subsequent fertility. About 35% of the couples wanting to limit children had undergone pregnancy or childbirth, while 76% of the couples wanting more children had conceived or given birth to children. In the case of discordance between the spouses, subsequent fertility was found to remain intermediate between those agreeing to continue childbirth and those wanting to limit it. The findings also affirmed that child sex preference, specifically son preference, still persists in Indian society. More than 80% of the couples with only daughters in IHDS-I mutually wanted to have additional children, whereas in families that only had sons, the chance of a subsequent pregnancy was inversely associated with the number of sons. Strong patriarchal settings, combined with cultural and socioeconomic factors, affect the persistence of sex preference in India. Programmes aimed at increasing family planning use need to address son preference and should include components that promote the value of girl children.</jats:p
The Politics of the Pedagogy: Cripping, Queering and Un-homing Health Humanities
No full textDrawing upon progressive pedagogical theorists and her own experiences, the author examines the potential effects and ethical responsibility of the health humanities workshop/classroom. Is it possible to search for oppositional knowledge—as described by Talpade Mohanty—within the health humanities disciplines; what does it mean to crip, queer, or un-home these many fields? In what ways might narrative work pose risks to students when it is practiced without attention to the operation of power and privilege? The author describes the evolution of her own pedagogical approach and proposes three pedagogical pillars to guide socially just narrative practices: narrative humility, structural competency, and engaged pedagogy. By embracing the state of being “un-homed”, the health humanities may strive to become a multiply layered space and time that both affirms difference and provides an alternative to authoritarian power and oppression.</p
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