65 research outputs found
A novel dry method for surface modification of SU-8 for immobilization of biomolecules in Bio-MEMS
SU-8 has been primarily used for structural elements and microfludics components in MEMS. Microsystems for biological applications require immobilization of biomolecules on the MEMS structures. In order to functionalize SU-8 for such purposes, the surface needs to be modified. In this paper, we report a novel dry method of surface modification of SU-8 which is compatible with standard microfabrication techniques. The surface obtained by spin coating SU-8 (2002) on silicon wafer was modified by grafting amine groups using pyrolytic dissociation of ammonia in a hotwire CVD setup. To demonstrate the presence of amine groups on modified SU-8 surface, the surface characteristic after modification was assessed using Fourier transform infrared spectroscopy. The change in SU-8 surface morphology before and after surface modification was investigated using atomic force microscopy. To show the utility of this process for application in Bio-MEMS, SU-8 microcantilevers were fabricated and subjected to the same surface modification protocol. Following this, the cantilevers were incubated first in a suspension of human immunoglobulin (HIgG) and then in FITC tagged goat anti-human IgG in order to demonstrate the utility of the surface modification performed. The efficacy of the process was assessed by observing the cantilevers under a fluorescence microscope
Response surface optimization for development of Dragon fruit based ready to serve drink
Dragon fruit based ready to serve drink (RTS) was formulated using dragon fruit (60-80% v/v), grape juice (0-10% v/v) and sugar syrup (2-6% v/v). The juice concentrations were optimized using response surface methodology (RSM) following box-behnken design (BBD) for obtaining blended RTS drink with higher functional and nutritional characteristics like total soluble solid (TSS), titratable acidity, ascorbic acid content, total phenol content, colour and sensory evaluation. Results showed that there was significant (P<0.01) effect of incorporating grape juice and sugar syrup which further improved the organoleptic properties of the blended RTS.Optimum juice percentages obtained for the best blend formulation were,dragon fruit (70%), grape juice (5%) and sugar syrup (3%), respectively. The beverage was observed to be acceptable in terms of its nutritional value and overall acceptability
PALAEOFLOOD RECORDS FROM UPPER KAVERI RIVER, SOUTHERN INDIA: EVIDENCE FOR DISCRETE FLOODS DURING HOLOCENE
Abstract: A record of six discrete middle Holocene floods has been established based on sedimentological and stratigraphical studies in the upper Kaveri catchment at Siddapur. The flood events are represented by six discrete, sharp-bounded, sand-silt couplets. Texturally and geochemically the suite of couplets is quite distinct from the overlying and underlying structureless fluvial deposits. Based on OSL ages the suite of couplets cover the Holocene from ~8 to ~2 ka. Such evidence is not present or reported from any other river originating in the Western Ghat in the Indian Peninsula. We argue that the six couplets represent short-term, high discharge events or flash floods. The initiation of this phase of flash floods broadly corresponds with the southward migration of ITCZ and a gradual decline in Indian summer monsoon precipitation starting at ~7.8 ka. Comparison of the elevation of the highest couplet with the high flood level (HFL) of the 1961 extraordinary flood on Kaveri demonstrates that the 20th century flood was higher than the mid-Holocene palaeofloods
Biofunctionalized Capillary Flow Channel Platform Integrated with 3D Nanostructured Matrix to Capture Circulating Tumor Cells
Circulating tumor cells (CTCs) from peripheral blood account genetic information for cancer diagnosis and overall disease monitoring. Analysis of “liquid biopsy” holds immense promise as it may lead to new approaches for cancer treatment. The study reports effective and continuous flow microchannel system for isolating CTCs using transferrin conjugated 3D matrix synthesized by crosslinking polyethylene glycol-Fe3O4 nanostructures for rapid and efficient capturing of CTCs. The platform provides option of using multiple microchannel units in series that can influence higher cell-capture efficiency due to increasing cell-substrate contact frequency. CTCs are captured with high efficiency even at low concentration of target cells (~90% at 25 cells per mL blood). Furthermore, the study demonstrates that the cell-capture performance is influenced by topographic interactions between nanostructure based matrix and cancer cells of interest. In addition, this study demonstrates the “proof of concept” using 3D microchannel system having capacity of simultaneously capturing and permanently eliminating CTCs from peripheral blood samples. Further, the study evaluates clinical samples of colon and breast cancer patients for rapid isolation of CTCs. Conclusively, the present platform demonstrates inordinate capacity for cancer cell sorting, biological studies of CTCs, and cancer metastasis, potentially benefiting the real time liquid biopsy and early prognosis of cancer
Interface engineering of SRu-mC(3)N(4) heterostructures for enhanced electrochemical hydrazine oxidation reactions
Hydrazine oxidation in single-atom catalysts (SACs) could exploit the efficiency of metal atom utilization, which is a substitution for noble metal-based electrolysers that results in reduced overall cost. A well-established ruthenium single atom over mesoporous carbon nitride (SRu-mC(3)N(4)) catalyst is explored for the electro-oxidation of hydrazine as one of the model reactions for direct fuel cell reactions. The electrochemical activity observed with linear sweep voltammetry (LSV) confirmed that SRu-mC(3)N(4) shows an ultra-low onset potential of 0.88 V vs. RHE, and with a current density of 10 mA/cm(2) the observed potential was 1.19 V vs. RHE, compared with mesoporous carbon nitride (mC(3)N(4)) (1.77 V vs. RHE). Electrochemical impedance spectroscopy (EIS) and chronoamperometry (i-t) studies on SRu-mC(3)N(4) show a smaller charge-transfer resistance (R-Ct) of 2950 omega and long-term potential, as well as current stability of 50 h and 20 mA/cm(2), respectively. Herein, an efficient and enhanced activity toward HzOR was demonstrated on SRu-mC(3)N(4) from its synergistic platform over highly porous C3N4, possessing large and independent active sites, and improving the subsequent large-scale reaction.Web of Science1212art. no. 156
Plasma treatment in textile industry
Plasma technology applied to textiles is a dry, environmentally- and worker-friendly method
to achieve surface alteration without modifying the bulk properties of different materials.
In particular, atmospheric non-thermal plasmas are suited because most textile materials
are heat sensitive polymers and applicable in a
continuous processes. In the last years plasma
technology has become a very active, high growth
research field, assuming a great importance among
all available material surface modifications in
textile industry. The main objective of this review
is to provide a critical update on the current state of
art relating plasma technologies applied to textile
industryFernando Oliveira (SFRH/BD/65254/2009) acknowledges Fundacao para a Cioncia e Tecnologia, Portugal, for its doctoral grant financial support. Andrea Zille (C2011-UMINHO-2C2T-01) acknowledges funding from Programa Compromisso para a Cioncia 2008, Portugal
Bird Species in Urban and Agricultural Landscapes : Bird diversity patterns along an urbanisation gradient and crop damage caused by birds on the Deccan Plateau, India
The major human activities that have transformed the Earth include agriculture and urbanization. The present study was conducted to contribute to a description of the effect on birds of urbanization and agriculture in an Indian region. Terrestrial bird assemblages were censused along a five-stage urbanisation gradient between January and April 2010-2013 near the city of Amravati, on the Deccan Plateau, Central India. Altogether, 89 species of birds were recorded, with the highest species richness in the rural areas (67 species) and lowest in the urban stage (29 species). The assemblages were significantly nested in all the five stages. Maximum cumulative species abundance (12 399 individuals over four years) was found in the urban stage, and was due to the constant presence of large groups of Rose-ringed Parakeets (Psittacula krameri). The lowest bird abundance was found in the industrial zone (4837 in total), where there was also a nearly two-fold decrease from 2010 to 2013. Thirty-six species demonstrated significant variation in their densities at least in one stage and between at least two months (p<0.05). Densities of 13.9% (n=5) of those species varied significantly in two stages, that of Copsychus saularis in three stages, and of Phoenicurus ochruros, in all five stages. Urban, suburban, periurban and forest stages were characterised by relatively stable species densities (significant changes observed only for 17.2% (n=5), 17.1% (n=6), 12.9% (n=7), and 17.8% (n=16) species, respectively). The additive diversity partitioning indicated that of the overall diversity (gamma-diversity), alpha diversity (within transects located within one stage) contributed 50.1% to the total diversity, and the controbution of within-stage variability was small (2.7%). Additionally, censuses on cultivated fields were taken. In two areas under mixed cropping systems, 53 bird species were identified in the two years period between June and December, 2011 and 2012. Out of the 53 detected species, only 14 were common (recorded at ≥50% of visits). Twenty-one species were recorded at Zadgaon in crops of tur (Cajanus cajan), cotton (Gossypium arboreum) and soybean (Glycine max). Nineteen species were recorded at Bhankhed in jawar (Sorghum bicolor), cotton and mung bean (Phaseolus aureus). At Zadgaon, territorial activity was observed in four species: the House Sparrow (Passer domesticus), Jungle Babbler (Turdoides striata), Yellow-eyed Babbler (Chrysomma sinense) and Red-wattled Lapwing (Vanellus indicus). The study indicated that four bird species were found under high risk, thirteen species at medium risk and eight species at low risk due to pesticide applications in croplands. The extent of crop damage in fields of groundnut, pearl millet, peas, sorghum, and sunflower was assessed by doing actual field censuses. The sustainable solution for reducing crop damage is a need for the farmers and such techniques will help to avoid direct or indirect effects of use of lethal bird control techniques on bird species diversity.QC 20141022</p
Rose Bengal-conjugated gold nanoparticles: quantification of singlet oxygen generation in photodynamic therapy
Empirical thesis.Bibliography: pages 44-50.1. Introduction -- 2. Photodynamic therapy background -- 3. Instrumentation and analysis methods for nanomaterials characterization -- 4. Experimental procedure, results and discussion -- 5. Conclusions and future works -- List of acronyms/abbreviations -- References.Photodynamic therapy (PDT) is an advanced novel methodology for the treatment of cancers using photosensitizers (PSs) which upon irradiating light generate cytotoxic singlet oxygen (¹O₂) and kills cancer cells. The utilization of photosensitizers has some restrictions, like low coefficient of extinction, low ¹O₂ generation efficiency and cannot be used for treating deep-seated tumours. Nanoparticles (NPs) have various properties that can be applied in PDT to overcome the limitations of PSs.The main aim of this work is, therefore, to enhance the ¹O₂ generation efficiency of the photosensitizer Rose Bengal (RB) by conjugating it with the Gold nanoparticles (AuNPs). The quantitative measurement of ¹O₂ generation is carried out on photosensitizer RB, AuNPs, and Au-NPs conjugated RB (AuRB). The fluorescence probe Singlet Oxygen Sensor Green (SOSG) was used to detect the ¹O₂. In a systemic study, the dependence of fluorescence on AuRB conjugation with different PS concentrations and the light-irradiation time for ¹O₂ generation are performed. Finally, the singlet oxygen quantum yield (SOQY) measurements are carried from the calculation of the rate of reaction and discussed. The results of the project state the improvement in ¹O₂ generation efficiency of PS on conjugation with the NPs.The successful NP-PS conjugation and high SOQY give the motivation for further studies on the development of the new photosensitizer drugs to treat the cancer cells.Mode of access: World wide web1 online resource (xii, 50 pages) diagrams, graph
DYES AND CHEMICALS USED IN BIOMATERIAL STUDY AS STAINS FOR INVERTEBRATES
Most of the dyes used in histology and cytology are manufactured for use in the textile industry, printing, food, cosmetics and other colorant industries. Chemicals used in the study include dyes and stains; the stains used are eosin, acetocarmine, rose bengal, magnesium chloride, magnesium sulphate, cocaine, menthol, propylene phenoxetol, osmic mercuric chloride, mercuric chloride, acetic acid, glycerin alcohol, phenoxetol, nitric acid, potassium cyanide. The dyes and stains as chemicals are used to preserve whole mount or to anesthetize the large animals like trematodes, nematodes, cestodes, arthropods, and molluscs. The study of fresh water and marine invertebrates is not possible unless the use of above mentioned chemicals.QC 20130320</p
DYES AND CHEMICALS USED IN BIOMATERIAL STUDY AS STAINS FOR INVERTEBRATES
Most of the dyes used in histology and cytology are manufactured for use in the textile industry, printing, food, cosmetics and other colorant industries. Chemicals used in the study include dyes and stains; the stains used are eosin, acetocarmine, rose bengal, magnesium chloride, magnesium sulphate, cocaine, menthol, propylene phenoxetol, osmic mercuric chloride, mercuric chloride, acetic acid, glycerin alcohol, phenoxetol, nitric acid, potassium cyanide. The dyes and stains as chemicals are used to preserve whole mount or to anesthetize the large animals like trematodes, nematodes, cestodes, arthropods, and molluscs. The study of fresh water and marine invertebrates is not possible unless the use of above mentioned chemicals.QC 20130320</p
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