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Comparative Study between Words in Titles and Keywords of Some Articles on Knowledge Organisation
No full textThis paper has presented research trends in the area of knowledge organisation since 2002 to 2011. In all, the bibliographic details of 285 research articles on some thrust research areas of knowledge organisation as represented by three keywords, viz., classification and indexing, faceted classification and folksonomy, have been collected from Emerald E-journal Consortia hosted by UGC-INFONET and analysed to study the research trend. The growth of literature in this area shows a logistic pattern over the said span. The distribution of articles over journals has been studied and Journal of Documentation ranked top followed by Aslib Proceedings, The Electronic Library and Library Hi Tech for three specific subject areas consecutively. The frequencies of assigned keywords have been analysed and core keywords have been identified. The words in titles of 285 articles have been analysed and compared with the words in assigned keywords. Two indicators have been defined, viz., Matching Coefficient (MC) and Title-to-Keyword Ratio (TKR) to study the state of matching between these two types of word clusters after comparative study. There are so many MC as found for different articles ranging from 0 to 0.5. The MCs have been graded in a scale set according to their numerical values. In all, seven grades have been set to study the state of matching between two types of words. In general, percentage of bad matching outnumbers the good matching. As titles are assumed as a most concise abstract of an article, it is customary to assume words in title as true reflector of central theme of the same. If words in assigned keywords poorly match the same in titles, then it may be logically inferred that keywords are incorrectly assigned for majority articles
Development of facile methods for the synthesis of heterocycles
No full textHeterocyclic compounds have attracted considerable pharmacological and synthetic interest as they have been identified in many biologically important scaffolds. Therefore development of efficient and elegant methodologies for the synthesis of novel fused
heterocycles is a challenging task in organic chemistry. The research work embodied in this thesis describes efficient and elegant protocols for the synthesis of (E)-3-arylidene- 3,4-dihydro-2H-1,4-benzoxazines/-2H-naphtho[2,1-b][1,4]oxazines, pyrazole fused
benzoxazines and triazole fused benzo-heterocycles employing palladium and/or copper catalyzed reactions and 1,3-dipolar cycloaddition. The work has been presented in three chapters
Phenazinium Dyes Methylene Violet 3RAX and Indoine Blue Bind to DNA by Intercalation: Evidence from Structural and Thermodynamic Studies
No full textThe structural and energetic aspects of the interaction of two important phenazinium dyes methylene
violet 3RAX and indoine blue with DNA were studied by spectroscopic and thermochemical techniques.
The binding affinity values of both the dyes were of the order of 105 M�1 but methylene violet 3RAX
bound to DNA more strongly. Both dyes bound DNA by intercalation but methylene violet 3RAX bound
stronger than indoine blue. The DNA binding of both the dyes was exothermic and favoured by a small
negative enthalpy and positive entropy contributions. The effect of ionic strength indicated that
electrostatic attraction is an important component of the dyeeDNA interaction although the major
contribution comes from hydrophobic forces. The temperature dependence of enthalpy changes yielded
negative heat capacity value which was higher for methylene violet 3RAX compared to indoine
blue suggesting higher contribution from hydrophobic forces in the interaction of the former.
Enthalpyeentropy compensation phenomenon was observed for the binding of both dyes to DNA
Studies on The Role of Pitx2 Homeodomain Transcription Factor to Maintain Ovarian Structure and Function
No full textThe bicoid-related homeobox gene Pitx2 is a member of a multi gene family with multiple functional aspects. Pitx2, have been first implicated in pituitary development and transcriptional regulation (Gaje PJ et al., 1997, 1999). Later on, extensive studies demonstrated that Pitx2-deficient mice are embryonic lethal and showed severe defects in heart, eye, pituitary and tooth organogenesis
(Ai D et al., 2007; Lin CR et al., 1999). Three different isoforms of PITX2 (PITX2A/B/C) differ only in their amino terminus and differentially regulate transcription of their target genes (Ganga M et al., 2003; Vadlamudi U et al., 2005). The Pitx isoforms are members of bicoid class of homeodomain transcription factors and besides Plod2 gene, they regulate genes like LHβ, FSHβ, GH, PRL and GnRH
receptor (Quentien MH et al, 2002; Tremblay JJ et al, 2000, 1998) by interacting with cell-restricted factors such as Steroidogenic Factor1 (SF-1), Early Growth Response-1 (Egr-1), the heterodimeric NeuroD1/ Pan1, Tpit and Pit1 (Quentien MH et al, 2002). Pitx2 controls cell cycle regulating genes, such as cyclin D1 and -D2 as well as it regulates Wnt dependent mRNA turn over (Briata P et al, 2003). Pitx isoforms regulate the expression of other transcription factors, like Hesx1, Prop1, Lhx3 and Gata2
(Charles MA et al, 2005). Upon finding of the expression of PITX2 in ovary (Ghosh P et al., 2007), we speculated its significant involvement in maintaining the ovarian structural integrity. The extracellular matrix (ECM) proteins, especially collagens play very critical role in
maintaining the normal function of ovary. Procollagen Lysine 2-oxoglutarate 5-dioxygenase (Plod) is
the key enzyme responsible for hydroxylation of lysines in collagens that plays a role in specifying the
ECM and provides a foundation for the morphogenesis of tissues and organs (Cox CJ et al, 2002). Three Plod isoforms have been characterized in human, mouse and in rats. The ECM has an important role in the formation and maintenance of follicles and corpora lutea (Vogel W et al, 1997; Luck MR,1994; Rodgers HF et al, 1998, 1999; Belkin AM & Stepp MA, 2000). PLOD, a peripheral membrane
protein (within the endoplasmic reticulum), catalyses lysine hydroxylation in collagens and more than
15 other proteins (Rautavuoma K et al, 2002). The Plod2 is under the regulation of Pitx2 in tissues like
mice brain and the proximal promoter region of Plod2 harbors multiple bicoid elements that bind to
Pitx2 (Hjalt et al., 2001)
Signal Networking And T Regulatory Cells In Cancer: Role Of Mahanine As A Potential Chemotherapeutic Agent
No full textCancer is known as a malignant neoplasm. Unregulated cell division and growth are accounted for this cancer condition. Cancerous cell can invade nearby or distant organs of the body through the lymphatic system or bloodstream. This adverse condition is mainly known as metastasis. Upon metastasis secondary malignancy can be formed from the primary tumorigenesis. In contrary, benign tumors don’t develop uncontrollably, not invade other tissues and not metastasize throughout the body. There are hundreds of different malignancies that are known to affect human system and other organisms. On the basis of the origination site, cancer can be subdivided into four parts, leukemia, carcinoma, lymphoma and sarcoma. Here we will mainly discuss about leukemia and glioma, a type of aggressive carcinoma. However it can be accounted that lymphoma is mainly associated with lymph node specific malignancy whereas sarcoma is the muscle cell cancer
Functional Studies On The Host Pathogen Interaction In Experimental Leishmania Donovani Infection Thesis
No full textLeishmaniasis is a disease complex caused by 17 different species of protozoan parasites belonging to the genus Leishmania. The parasites are transmitted between mammalian hosts by phlebotomine sandflies. Leishmaniasis has a worldwide distribution with important foci of infection in Central and South America, southern Europe, North and East Africa, the Middle East, and the Indian subcontinent. Most forms of leishmaniasis are zoonotic, human beings affected only secondarily, but two species of Leishmania can maintain arthroponotic, human-human cycle. These are L. donovani, the species responsible for VL in the Indian subcontinent and East Africa, and L. tropica, which is responsible for CL in the old World
Molecular basis of the Competitive Exclusion of Vibrio Cholerae Classical Biotype by the el Tor Biotype
No full textVibrio cholerae is the causal organism of the diarrheal disease cholera. The first six pandemics of cholera occurred between 1817 and 1961 and were caused by classical
biotype. In 1961, the El Tor biotype emerged in Indonesia to cause the ongoing seventh cholera pandemic and within a decade displaced the classical biotype as the causal
organism of epidemic cholera. Such a rapid displacement of an existing pathogen by a newly emerged one was a unique event in bacterial epidemiology. Despite the accumulation of several facts about the molecular differences between the El Tor and the classical biotypes, the genetic basis of this phenomenon is still unknown. In this present
study attempts have been made to elucidate the nature of fitness gained by the El Tor biotype over the classical biotype in cocultures and the molecular basis of exclusion of the classical biotype in cocultures with the El Tor biotype. We demonstrate that when strains of
the V. cholerae El Tor and classical biotype were cocultured in standard LB medium, the El Tor strains had a competitive growth advantage over the classical biotype starting from the late stationary phase and could eventually take over the population. The possibility of
nutrients being present in the stationary phase culture filtrates of the classical biotype stationary phase cultures were next examined. So, when the El Tor biotype cells were grown in the conditioned medium from the stationary phase classical biotype cultures it
derived a marked growth advantage. Next, it was observed that indeed the classical biotype produces extracellular protease(s) in the stationary phase, and the amounts of amino acids and small peptides in the late stationary phase culture filtrates of the classical biotype were
higher than those in the corresponding culture filtrates of the El Tor biotype. The El Tor biotype cells could utilize the amino acids more efficiently than the classical biotype cells under the alkaline pH of the stationary phase cultures. The growth advantage of the El Tor
biotype was also observed in vivo using the ligated rabbit ileal loop and infant mouse animal models. Subsequently the nature of competitive exclusion of the classical biotype
cells in the cocultures with El Tor biotype was investigated. It was observed that when the El Tor and classical biotypes were cocultured in standard laboratory medium a precipitous decline in colony forming units (CFU) of the classical biotype occurred in a contact dependent manner. Several lines of evidence including DNA release, microscopy and flow cytometric analysis indicated that the drastic reduction in CFU of the classical biotype in
cocultures was not accompanied by lysis, although when the classical biotype was grown individually in monocultures, lysis of the cells occurred concomitant with decrease in CFU
starting from late stationary phase. Furthermore, uptake of a membrane potential sensitive dye and protection of genomic DNA from extracellular DNases strongly suggested that the classical biotype cells in cocultures retained viability. These results suggest that coculturing
the classical biotype with the El Tor biotype protects the former from lysis allowing the cells to remain viable in spite of the loss of culturability. The stationary phase sigma factor RpoS may have a role in the loss of culturability of the classical biotype in cocultures.
Although competitive exclusion of closely related strains has been reported for several bacterial species, conversion of the target bacterial population to the viable non-culturable state has not been demonstrated previously and may have important implications in the evolution and epidemiology of bacterial strain
Transplantation studies in animal models of Parkinson�'s Disease
No full textParkinson’s disease (PD) is a neurodegenerative disorder, resulting from the loss of dopaminergic (DA-ergic) neurons from the substantia nigra pars compacta (SNpc) region of the brain. These cells form an integral part of the basal ganglia, an area responsible for motor coordination in mammals. In humans and subhuman primates, loss of these cells results in akinesia, rigidity, postural instability and tremor, and these symptoms progress as the loss of neurons from this region accelerates. Cell replacement therapy is considered as an obvious option for the recovery of lost motor functions resulting from the loss of neurons. This is relevant for PD owing to failures of available pharmacological approaches. Moreover, it was thought to be theoretically feasible because of the loss of only a particular segment of the CNS DA-ergic systems, the A9 DA-ergic neurons, the terminals of which are in each of
the striatum. Additionally, the anatomical location of the terminal region is an accessible site for any surgical interventions. A simple technique of placing dopamine secreting cells at the site of the A9 SNpc neuronal terminals would provide the neurotransmitter required for stimulating postsynaptic neurons in the area. The next problem could be engineering the transplanted neurons to release dopamine to specific stimuli. However, in practice, even transplanting dopamine releasing neurons in the striatum met with difficulties. To add to the woes, the varied outcomes of transplantation studies made it difficult to decipher the exact problem(s). Ultimately, what remains as of now are a bunch of speculations in regard
to the failures or inconclusive outcomes of this therapeutic option. The major problems associated with cell replacement therapy in PD seem to be (i) the availability of implant material, (ii) its source, (iii) nature of the material, (iv) survivability of the cells in the grafts, and finally (v) fate of the transplants in long term grafts. Last, but not the least, the graft associated abnormalities in the host is a major unresolved issue
Development of new methods for glycosylation and syntheses of heterocycles containing sugar molecules
No full textThe studies embodied in this thesis include the development of a new glycosylation method suitable for one-pot glycosylation strategies, and the synthesis of carbohydrate based heterocycles. The total work was carried out in the Department of Chemistry (Carbohydrate), CSIR-Indian Institute of Chemical Biology, Kolkata (India), under the planning and guidance of Dr. Asish Kumar Sen, Chief Scientist, of the same Institute. The thesis is broadly divided into two chapters. Chapter 1: This chapter is divided into two parts. Part A contains a brief review of the different methods for glycosylation developed in recent times. Some examples of synthesis of biologically active compounds along with references have been incorporated.Part B describes the use of iodine for efficient and chemoselective glycosylation using glycosyl ortho-alkynylbenzoates as donor. This glycosylation reaction can also be achieved selectively in presence of thioglycosides. This attribute was utilized for the synthesis of a manno-trisaccharide in one-pot condition. The introduction to the work, results and discussion, experimental procedures, conclusion, spectroscopic data and related references are included in this part. The work has been published in Tetrahedron Lett. 2013, 54, 865- 870.Chapter 2: This chapter is divided into three parts. Part A deals with a brief review of the recently developed methods used for the synthesis of triazoles, especially carbohydrate-triazole conjugates. The syntheses of some important biologically active compounds along with related references are also incorporated. Part B includes the one-pot synthesis of triazole-O-glycoconjugates and triazolyl glycoconjugates. The methodology combines a glycoylation and azide alkyne cycloaddition in one-pot to form triazole-O-glycoconjugates and triazolyl glycosides. The glycosylation reaction was promoted by silver triflate which also oxidized Cu(0) for the following cycloadditiion step. The introduction to the work, results and discussions, experimental procedures, conclusion, spectroscopic data and related references are included. Part C describes the one-pot synthesis of 1,2,3-triazoles linked chiral 2- substituted benzimidazoles. CuI used in the reaction procedure plays a dual role in promoting a aldehyde functionality for oxidative cyclization and activating a terminal carbon-carbon triple bond to undergo azide-alkyne cycloaddition. The introduction to the work, results and discussion, experimental procedures, conclusion, spectroscopic characterization data and related references are included. The work was published in J. Heterocyclic Chem. 2013, 50, 689-695.Finally, the list of the published papers and reprints are attached
Studies on Molecular Mechanisms Associated with Narcotic Addiction
No full textThe term addiction is used in many contexts to describe an obsession, compulsion or excessive psychological dependence. Addiction is the state of being enslaved to a habit or practice or to something that is psychologically or physically habit-forming, to such an extent
that its cessation causes severe psychological or physical discomfort. According to definition by the Diagnostic and statistical manual of mental disorders, 4th edn. [DSM-IV-TR], American Psychiatric Association (1994), addiction is assumed to be identical to the syndrome of substance dependence. Nestler, the pioneer of work on addiction, defines addiction as a “complex phenomenon with important psychological and social causes and consequences’ [Nestler and Aghajanian, 1997]. According to the definition related to the use of opioids for the treatment of pain, jointly issued by ‘The American Academy of Pain Medicine, the American Pain Society, and the American Society of Addiction Medicine in 2001’, addiction is a “neurobiological, compulsive disorder in which an individual becomes preoccupied with obtaining and using a substance-- and experiences a lack of control over
using that substance -- despite continued use that results in a decreased quality of life and significant adverse consequences.” Addiction can be broadly classified into two major forms, namely substance and process. Substance addiction constitutes addiction to substances or drugs like nicotine, alcohol, opioids, stimulants etc. Process or behavioural addiction occurs where a person is repeatedly
engaged to a typical activity, like video game, work, computer, shopping, gambling, social networking, etc. It is increasingly clear from recent studies that many of these behavioural addiction phenomenons in individuals have similar symptoms of substances addiction and undergo the same consequences brought about by addiction to alcohol and drugs. Surprisingly, “non-substance related behavioral addiction” was not listed in either of the two
internationally used diagnostic manuals of mental disorders, DSM-IV-TR and International Classification of Disease