Insilico modeling of chitosan as a drug delivery system

Computational modeling of polymeric nanoparticles as drug carriers have been extensively studied due to their varied functionalities, tunable structures and the capability of controlled drug release. Nano particulate polymeric drug delivery systems enable a cell specific targeting with negligible side effects and drug release based on change in physiological conditions. Eight common polymers are modeled and the various properties have been predicted. ADMET, QSAR, thermodynamic and electronic properties have been predicted and compared using SAR as well as quantum mechanical density functional methods. Comparison of the predicted properties suggests that chitosan, which is a natural polymer and has some advantages over others is a promising drug carrier candidate for tumor

Novel 2,5-disubstituted-1,3,4-oxadiazole derivatives induce apoptosis in HepG2 cells through p53 mediated intrinsic pathway

AbstractA series of novel 1,3,4-oxadiazole derivatives (OSD, OCOD, ONOD, OPD, COD, PMOD, and PCOD) were synthesized and characterized. Their structures were confirmed on the basis of IR, NMR and mass spectroscopy and molecular weights were found in the range 300–325g/mol. Cancerous cell lines (MCF-7, HepG2) and non-cancerous cell lines (Chang liver cells) were treated with these compounds for 48h, which caused dose dependent decrease in the cell viability. From the seven derivatives, OSD was found to be most potent with IC50 value close to 50μM on all tested cell lines. Hence, this compound was selected for mechanistic study on HepG2 cell lines. Fluorescent cell staining and DNA fragmentation study of 50μM OSD on HepG2 cells, showed events marked by apoptosis such as nuclear fragmentation, cytoplasm shrinkage and DNA damage. Further, the cells with same treatment were quantified for apoptosis using annexin V-PI flow cytometric technique. The percentage of apoptotic cells was significantly higher (p<0.05) after OSD treatment compared to control cells. OSD induced a significant increase (p<0.05) in the expression of the tumor suppressor p53 in HepG2 cells. The constitutive expression of anti-apoptotic protein Bcl-2 significantly decreased (p<0.05) after treatment, while the expression of proapoptotic protein Bax significantly increased (p<0.05). The change in Bax to Bcl-2 ratio suggested involvement of Bcl-2 family in induction of apoptosis. Furthermore, the levels of caspase-9 and caspase-3 were significantly (p<0.05) up regulated in HepG2 cells after OSD treatment. The data suggest that 1,3,4-oxadiazole derivatives induce apoptosis mediated by intrinsic pathway of apoptosis. The findings strengthen the potential of the 1,3,4-oxadiazole scaffold OSD, as an agent with chemotherapeutic and cytostatic activity in human hepatocellular carcinoma in vitro

Synthesis, Characterization and Properties of Conductive Elastomeric Composites Based on Polypyrrole and Short Nylon-6 Fiber

The search for new materials especially those possessing special properties continues at a great pace because of ever growing demands of the modern life. The focus on the use of intrinsically conductive polymers in organic electronic devices has led to the development of a totally new class of smart materials. Polypyrrole (PPy) is one of the most stable known conducting polymers and also one of the easiest to synthesize. In addition, its high conductivity, good redox reversibility and excellent microwave absorbing characteristics have led to the existence of wide and diversified applications for PPy. However, as any conjugated conducting polymer, PPy lacks processability, flexibility and strength which are essential for industrial requirements. Among various approaches to making tractable materials based on PPy, incorporating PPy within an electrically insulating polymer appears to be a promising method, and this has triggered the development of blends or composites. Conductive elastomeric composites of polypyrrole are important in that they are composite materials suitable for devices where flexibility is an important parameter. Moreover these composites can be moulded into complex shapes

Evaluation of a diatom eDNA-based technique for assessing water quality variations in tropical lakes and reservoirs

Freshwater bodies, both lotic (canals, rivers) and lentic (lakes and reservoirs), in the tropics have only rarely been subjected to intense monitoring regimes owing to limited expertise and resources, despite tropical habitats being among the most dynamic and threatened globally. Diatoms are an important part of assessing aquatic environmental changes in parts of the world where monitoring is well-established because of their sensitivity to a range of indicators of water quality. In such cases, diatoms have traditionally been identified based on morphology. Morphological information on tropical diatom taxa and the expertise to assemble it are sparse. However, DNA-based assessment is less reliant on taxonomic expertise and has the potential to be more cost-efficient. The application of DNA-based technology could thus expedite the incorporation of diatoms into routine monitoring in the tropics. Here we evaluate an environmental DNA (eDNA) metabarcoding workflow for diatom identifications based on 109 water samples from six freshwater reservoirs in Singapore, a highly urbanised part of tropical Southeast Asia. The six reservoirs span a range of sizes and catchment settings. We generate baseline information for lentic systems by targeting planktonic assemblages and including two commonly used barcodes, rbcL and 18S, to assess detection differences. Congruence with morphological identifications is generally low and each technique reveals distinct species lists, but overall congruence between methods improves when comparisons are at the genus level. We discuss the probable methodological and analytical causes for this incongruence and conclude that both approaches be used concurrently for generating reference databases of relatively poorly-known diatom diversity in tropical freshwater habitats. More promisingly, we find that eDNA datasets were sufficient to reveal both spatial and temporal patterns in diatom assemblages across the six study sites. We also show that regardless of the detection method used, diatom assemblages correlated with similar environmental variables. Results highlight the potential feasibility of eDNA-based diatom monitoring of freshwater habitats in Southeast Asia and in the tropics more broadly

Distribution of foraminifera in the lagoons of certain islands of the Lakshadweep archipelago, Arabian Sea

161-178A total of 107 foraminiferal species belonging to 29 families and 48 genera have been identified from the lagoonal sediments of Agatti, Kavaratti, Suhelipar, and Minicoy atolls of Lakshadweep. The fauna is dominated by calcareous Foraminifera, but arenaceous forms are very rare due to coarse nature of the deposits. Of the families observed, Miliolidae, Calcarinidae, and Amphisteginidae are most abundant and 2 species, Calcarina calcar and Amphistegina radiata are the most dominant. Planktonic Foraminifera are very rare and those few present in the lagoons have been transported by water currents through passages of the reef. In general, Foraminifera of the coral reefs in the coastal waters of Indian peninsula are similar in their species composition. Larger foraminiferids and typical coral-reef species of the fauna from Lakshadweep have been reported. The role of Foraminifera as reef-builders and their distribution as related to ecology are evaluated. The data suggest that there is a similarity of the reef faunas from tropical Indo-Pacific and Atlantic Oceans

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Not AvailableStagnation and decline in productivity of most of the agricultural and plantation crops in Kerala, despite the genetic improvements in crop varieties and heavy external inputs of fertilisers and pesticides, prompted the Kerala State Planning Board to embark on a massive project to identify and map the soil related constraints to crop production. Highly weathered laterite soils, covering most of the state, are relatively infertile, acidic, gravelly clay depleted of basic cations and possessing low water and nutrient retention capacity. In order to assess the soil fertility in the state and to elucidate the soil related constraints nearly two lakh composite surface soil samples were collected from farmer’s fields all over the state and analysed for soil reaction, macro, secondary and micronutrients. Extensive acidification of the soils, build up of high levels of phosphorus and deficiencies of calcium, magnesium and boron were found to be the major soil related constraints in the state.Not Availabl

Beyond Drosophila: resolving the rapid radiation of schizophoran flies with phylotranscriptomics

Background The most species-rich radiation of animal life in the 66 million years following the Cretaceous extinction event is that of schizophoran flies: a third of fly diversity including Drosophila fruit fly model organisms, house flies, forensic blow flies, agricultural pest flies, and many other well and poorly known true flies. Rapid diversification has hindered previous attempts to elucidate the phylogenetic relationships among major schizophoran clades. A robust phylogenetic hypothesis for the major lineages containing these 55,000 described species would be critical to understand the processes that contributed to the diversity of these flies. We use protein encoding sequence data from transcriptomes, including 3145 genes from 70 species, representing all superfamilies, to improve the resolution of this previously intractable phylogenetic challenge. Results Our results support a paraphyletic acalyptrate grade including a monophyletic Calyptratae and the monophyly of half of the acalyptrate superfamilies. The primary branching framework of Schizophora is well supported for the first time, revealing the primarily parasitic Pipunculidae and Sciomyzoidea stat. rev. as successive sister groups to the remaining Schizophora. Ephydroidea, Drosophila&apos;s superfamily, is the sister group of Calyptratae. Sphaeroceroidea has modest support as the sister to all non-sciomyzoid Schizophora. We define two novel lineages corroborated by morphological traits, the &apos;Modified Oviscapt Clade&apos; containing Tephritoidea, Nerioidea, and other families, and the &apos;Cleft Pedicel Clade&apos; containing Calyptratae, Ephydroidea, and other families. Support values remain low among a challenging subset of lineages, including Diopsidae. The placement of these families remained uncertain in both concatenated maximum likelihood and multispecies coalescent approaches. Rogue taxon removal was effective in increasing support values compared with strategies that maximise gene coverage or minimise missing data. Conclusions Dividing most acalyptrate fly groups into four major lineages is supported consistently across analyses. Understanding the fundamental branching patterns of schizophoran flies provides a foundation for future comparative research on the genetics, ecology, and biocontrol.Y