60 research outputs found
XPS characterization of (copper-based) coloured stains formed on limestone surfaces of outdoor Roman monuments
Limestone basements holding bronzes or other copper alloys artefacts such as sculptures, decorations and dedicatory inscriptions are frequently met both in modern and ancient monuments. In outdoor conditions, such a combination implies the corrosion products of the copper based alloy, directly exposed to rainwater, will be drained off and migrate through the porous surfaces, forming stains of different colours and intensities, finally causing the limestone structures to deteriorate
DNA Aptamers as Molecular Probes for Colorectal Cancer Study
Understanding the molecular features of specific tumors can increase our knowledge about the mechanism(s) underlying disease development and progression. This is particularly significant for colorectal cancer, which is a heterogeneous complex of diseases developed in a sequential manner through a multistep carcinogenic process. As such, it is likely that tumors with similar characteristics might originate in the same manner and have a similar molecular behavior. Therefore, specific mapping of the molecular features can be potentially useful for both tumor classification and the development of appropriate therapeutic regimens. However, this can only be accomplished by developing high-affinity molecular probes with the ability to recognize specific markers associated with different tumors. Aptamers can most easily meet this challenge based on their target diversity, flexible manipulation and ease of development.Using a method known as cell-based Systematic Evolution of Ligands by Exponential enrichment (cell-SELEX) and colorectal cancer cultured cell lines DLD-1 and HCT 116, we selected a panel of target-specific aptamers. Binding studies by flow cytometry and confocal microscopy showed that these aptamers have high affinity and selectivity. Our data further show that these aptamers neither recognize normal colon cells (cultured and fresh), nor do they recognize most other cancer cell lines tested.The selected aptamers can identify specific biomarkers associated with colorectal cancers. We believe that these probes could be further developed for early disease detection, as well as prognostic markers, of colorectal cancers
Brugia malayi Antigen (BmA) inhibits HIV-1 trans-infection but neither BmA nor ES-62 alter HIV-1 infectivity of DC induced CD4+ Th-cells
One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs
Aptamers for pharmaceuticals and their application in environmental analytics
Aptamers are single-stranded DNA or RNA oligonucleotides, which are able to bind with high affinity and specificity to their target. This property is used for a multitude of applications, for instance as molecular recognition elements in biosensors and other assays. Biosensor application of aptamers offers the possibility for fast and easy detection of environmental relevant substances. Pharmaceutical residues, deriving from human or animal medical treatment, are found in surface, ground, and drinking water. At least the whole range of frequently administered drugs can be detected in noticeable concentrations. Biosensors and assays based on aptamers as specific recognition elements are very convenient for this application because aptamer development is possible for toxic targets. Commonly used biological receptors for biosensors like enzymes or antibodies are mostly unavailable for the detection of pharmaceuticals. This review describes the research activities of aptamer and sensor developments for pharmaceutical detection, with focus on environmental applications
Efficient Organic Photovoltaics with Improved Charge Extraction and High Short-Circuit Current
Exciton generation, dissociation, free carrier transport, and charge extraction play an important role in the short-circuit current (J(sc)) and power conversion efficiency of an organic bulk heterojunction (BHJ) solar cell (SC). Here we study the impact of band offset at the interfacial layer and the morphology of active layer on the extraction of free carriers. The effects are evaluated on an inverted BHJ SC using zinc oxide (ZnO) as a buffer layer, prepared via two different methods: ZnO nanoparticle dispersed in mixed solvents (ZnO A) and sol-gel method (ZnO B). The device with ZnO A buffer layer improves the charge extraction and J(sc),. The improvement is due to the better band offset and morphology of the blend near the ZnO A/active layer interface. Further, the numerical analysis of current-voltage characteristics illustrates that the morphology at the ZnO A/active layer interface has a more dominant role in improving the performance of the organic photovoltaic than the band offset
<span style="font-size:15.0pt;mso-bidi-font-size: 11.0pt" lang="EN-GB">Establishment of an <i style="mso-bidi-font-style:normal">in vitro</i> plantlet regeneration protocol for unique varieties of brinjal (<i style="mso-bidi-font-style:normal"><span style="font-size:15.0pt; mso-bidi-font-size:11.0pt;mso-fareast-language:EN-IN;mso-bidi-font-weight:bold" lang="EN-GB">Solanum melongena</span></i><span style="font-size:15.0pt;mso-bidi-font-size: 11.0pt;mso-fareast-language:EN-IN;mso-bidi-font-weight:bold" lang="EN-GB"> L.) var. <span style="font-size:15.0pt;mso-bidi-font-size:11.0pt" lang="EN-GB">Mattu Gulla and Perampalli Gulla </span></span></span>
80-88Brinjal (<span style="font-size:9.0pt;
mso-bidi-font-size:11.0pt;mso-fareast-language:EN-IN;mso-bidi-font-weight:bold" lang="EN-GB">Solanum
melongena<span style="font-size:9.0pt;mso-bidi-font-size:
11.0pt;mso-fareast-language:EN-IN;mso-bidi-font-weight:bold" lang="EN-GB"> L.) var. Mattu
Gulla (MG) and var. Perampalli Gulla (PG) are unique varieties with distinct
flavour cultivated in Udupi, Karnataka State, and are exposed to several biotic
and abiotic stresses. An efficient and reproducible <i style="mso-bidi-font-style:
normal">in vitro regeneration method is required to expedite the
manipulation of these brinjal varieties to cope up with stress by tissue
culture and gene transfer methods. The present study, reports a rapid and
efficient in vitro regeneration
protocol for these two varieties. The in
vitro growth response was studied on Murashige and Skoog (MS) medium
supplemented with 2, 4-D, BAP and IAA, and the plantlets were regenerated
efficiently from callus cultures of leaf, cotyledon and hypocotyl explants.
Among the three explants, the hypocotyl explants were found to have better
callus induction and multiple shoot regeneration. High frequency of shoot
initiation was achieved from hypocotyl derived calluses in MS media with 2.0
mg/L<span style="font-size:9.0pt;mso-bidi-font-size:11.0pt;
mso-bidi-font-weight:bold;mso-bidi-font-style:italic" lang="EN-GB"> BAP and 0.5 mg/L IAA in
MG and PG. Efficient and rapid shoot proliferation, and elongation were noted
in MS medium with 1.0 <span style="font-size:9.0pt;
mso-bidi-font-size:11.0pt;mso-fareast-language:EN-IN;mso-bidi-font-weight:bold" lang="EN-GB">mg/L<span style="font-size:9.0pt;mso-bidi-font-size:11.0pt;mso-bidi-font-weight:
bold;mso-bidi-font-style:italic" lang="EN-GB"> BAP and 0.3 <span style="font-size:9.0pt;mso-bidi-font-size:11.0pt;mso-fareast-language:EN-IN;
mso-bidi-font-weight:bold" lang="EN-GB">mg/L<span style="font-size:9.0pt;
mso-bidi-font-size:11.0pt;mso-bidi-font-weight:bold;mso-bidi-font-style:italic" lang="EN-GB">
GA3. The in vitro regenerated shoots produced healthy roots
when they were cultured on MS medium supplemented with 0.5 <span style="font-size:9.0pt;mso-bidi-font-size:11.0pt;mso-fareast-language:
EN-IN;mso-bidi-font-weight:bold" lang="EN-GB">mg/L<span style="font-size:
9.0pt;mso-bidi-font-size:11.0pt;mso-bidi-font-weight:bold;mso-bidi-font-style:
italic" lang="EN-GB"> IBA. A significant difference was observed in percentage of callus
induction, number of shoots per callus, shoot elongation and number of hardened
plantlets of MG and PG. MG showed maximum response in all stages of culture
than PG. Hardening of plantlets in tissue culture was achieved in three weeks. The
hardened plantlets were grown in pots for further acclimatization in green
house and finally transplanted to experimental garden where they developed into
flowering plants and produced mature fruits with viable seeds.<span style="font-size:9.0pt;mso-bidi-font-size:11.0pt;mso-fareast-language:
EN-IN;mso-bidi-font-weight:bold" lang="EN-GB">
</span
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