1,177 research outputs found
Synthesis, Characterization, Spectroscopic, and Mesomorphic Studies of New Schiff Base Ligands and Titanium, Cobalt, Nickel and Copper Metal Centers
Transition metal complexes with Schiff base ligands offer a wide application in the field of development of catalysis and material. The straightforward synthesis allowed the structural modification and helped to optimize in various application of such complexes. Titanium-containing complexes have been reported to be important for their catalytic and material applications through the coordination of a tetradentate Schiff base ligand, viz. N, N’-ethylene bis(salicylideneiminate) dianion (salen). Studies reporting the characterization of achiral titanium(IV) salen complexes are scarce due to their intricate nature. Such complexes would be comparatively less expensive and easier to prepare synthetically and thus could represent an excellent alternative to the more expensive chiral titanium(IV) complexes. Our research group designed a series of octahedral titanium(IV) Schiff base complexes along with various substituted phenols as ligands, which were assessed for their purity and characterized using various methods and spectroscopic techniques such as elemental analysis, electrochemistry, UV-visible, 1H, 13C, 19F, and 49Ti NMR and FTIR spectroscopies. From the elemental analysis data, the complexes were proposed to have the general structural formula [Ti(salen)OPh-X)2] (where X = F, NO2 and CH3). The 49Ti-NMR spectral data showed chemical shifts in the range of +1160 ppm to +1170 ppm, which demonstrated that the magnetic environment showing an increase in the linewidth with molecular size for the particular titanium(IV) salen complex due to the presence of salen ligand.
Another study was focused on the preparation of liquid crystal material using Schiff base ligand and the first-row transition metal ions. To exhibit the liquid crystal property, the design of the ligand plays a vital role. Herein, we used 2,4-dihydroxybenzaldehyde to prepare precursor ligand, at the reactive para-position, the alkoxybenzyl attached to generate precursor aldehyde. Ortho-phenylenediamine was used to create novel tetradentate rigid core ligand with flexible alkoxy side chains. These ligands coordinate with Co(II), Ni(II), and Cu(II) metal ions resulting in square planar Schiff base complexes. This thesis is focused on the preparation of stable, pure, and well characterized liquid crystal complexes. Various methods were explored, optimizing the yield and purity. Mesomorphic behavior of the complexes was explored optically, thermally, and by using XRD techniques
Regeneration of plants from alginate-encapsulated shoots of Rhododendron dalhousiae Hook. F.
A method has been developed for plant regeneration from alginate-encapsulated nodal segments of Rhododendron dalhousiae. Shoot tips collected from in vitro proliferated shoots were used for synthetic seed production. For encapsulation, nodal segments were mixed with MS medium supplemented with 3% sodium alginate and incubated with calcium chloride (60 mM). The maximum frequency (69%) of conversion of encapsulated shoot tips into plantlets was achieved on MS medium containing 25 ?M 2-isopentenyladenine (2iP) along with additive such as, 100 mg L-l polyvinyl pyrrolidone (PVP), 100 mg L -l ascorbic acid, 10 mg L-l citric acid. The presence of 2iP (25 ?M) with IAA (0.6 ?M) improved re-generation. Amongst the two gelling agents used higher shoot proliferation as well as better growth were observed in cultures grown on Agar in comparison to Phytagel medium. Encapsulated nodal segments stored at 4°C for 25 days also showed successful conversion, followed by development into complete plantlets when returned to regeneration medium. Liquid medium was superior over solid medium for root formation and growth. IBA (1.0 ?M) was more effective than other auxins for root induction. Plantlets with developed shoot and roots were hardened off to survive ex vitro conditions and successfully established in greenhouse. Possibility of direct sowing of synthetic seeds in the soil was also examined
Bacterial ‘Cell’ Phones: Do cell phones carry potential pathogens?
Cell phones are important companions for professionals especially health care workers (HCWs) for better communication in hospital. The present study compared the nature of the growth of potentially pathogenic bacterial flora on cell phones in hospital and community. 75% cell phones from both the categories grew at least one potentially pathogenic organism. Cell phones from HCWs grew significantly more potential pathogens like MRSA (20%), Acinetobacter species (5%), Pseudomonas species (2.5%) as compared to the non HCWs. 97.5% HCWs use their cell phone in the hospital, 57.5% never cleaned their cell phone and 20% admitted that they did not wash their hands before or after attending patients, although majority (77.5%) knows that cell phones can have harmful colonization and act as vector for nosocomial infections. It is recommended, therefore, that cell phones in the hospital should be regularly decontaminated. Moreover, utmost emphasis needs to be paid to hand washing practices among HCWs
Morphological characterization and secondary metabolites profile of black pepper (Piper nigrum L.) genotypes from Sikkim
Quantification of volatile oil and analysis of four major metabolites using HPLC was done in 24 black pepper genotypes collected from south Sikkim. The amount of volatile oil ranged from 2.01% to 0.022%. Secondary metabolites like piperine ranged from 2.75-0.022%, myrcene from 2.094-0.022%, alpha- phellandrene from 1.373-0.008% and linalool from 0.834-0.012%. Genotype 23 had the highest amount of myrcene and linalool, genotype 13 had the highest quantity of piperine and genotype 8 had high amount of alpha-phellandrene. The principal component analysis (PCA) of analyzed metabolites grouped the genotypes into four categories. The study revealed that some of the genotypes were as good as pepper varieties grown in traditional areas. These genotypes will be useful in crop improvement strategies and suitable for Sikkim Himalaya
RIVER ECOLOGICAL STUDY: BUILDING THE KNOWLEDGE BASE FOR VARIETY OF ASSESSMENTS SUCH AS CLIMATE CHANGE IN NEPAL
Climate change is now universally acknowledged to be taking place across the globe. It is generally presumed that the impacts of climate change would be more severe in the country like Nepal due to its location, physiography, poverty and lack of preparedness to cope with the changes. The last reason is mainly associated with knowledge, information and ability to use technologies based on science.The main objective of this research is to analyze and evaluate the effects of climate change by taking fish as an indicator. However, an even more important outcome is to prepare a solid foundation of fish-based information, which could be used in the future as a reference for a variety of purposes including the study of climate change. Two sets of examples, one in the tributaries of a glacial river and another in the tributary of a rain -fed river are compared in terms of fish ecological attributes to test for effects of climate change. In addition to fish-based information, this research also studies physico-chemical parameters and benthic fauna so as to build up an ecological profile of the rivers
The association of women's empowerment with stillbirths in Nepal.
INTRODUCTION: Globally, 2.6 million stillbirths occur each year. Empowering women can improve their overall reproductive health and help reduce stillbirths. Women empowerment has been defined as women's ability to make choices in economic decision-making, household and health care decision-making. In this paper, we aimed to evaluate if women's empowerment is associated with stillbirths. METHODS: Data from 2016 Nepal Demographic Health Surveys (NDHS) were analysed to evaluate the association between women's empowerment and stillbirths. Equiplots were generated to assess the distribution of stillbirths by wealth quintile, place of residence and level of maternal education using data from NHDS 1996, 2001, 2006, 2011 and 2016 data. For the association of women empowerment factors and stillbirths, univariate and multivariate analyses were conducted. RESULTS: A total of 88 stillbirths were reported during the survey. Univariate analysis showed age of mother, education of mother, age of husband, wealth index, head of household, decision on healthcare and decision on household purchases had significant association with stillbirths (p < 0.05). In multivariate analysis, only maternal age 35 years and above was significant (aOR 2.42; 1.22-4.80). Education of mother (aOR 1.48; 0.94-2.33), age of husband (aOR 1.54; 0.86-2.76), household head (aOR 1.51; 0.88-2.59), poor wealth index (aOR 1.62; 0.98-2.68), middle wealth index (aOR 1.37; 0.76-2.47), decision making for healthcare (aOR 1.36; 0.84-2.21) and household purchases (aOR 1.01; 0.61-1.66) had no any significant association with stillbirths. CONCLUSIONS: There are various factors linked with stillbirths. It is important to track stillbirths to improve health outcomes of mothers and newborn. Further studies are necessary to analyse women empowerment factors to understand the linkages between empowerment and stillbirths
An Empirical Investigation on Customer’s Privacy Perceptions, Trust and Security Awareness in E-commerce Environment
Privacy concerns of the users have been listed as one of the hindrances in the growth of e-commerce. Understanding the consequences of privacy and its relationship with risk perceptions may help in finding solutions to this problem. Internet users may use different strategies to protect their privacy so that they can become confident in taking part in e-commerce. In this study, we investigate how users can lower their risk perceptions in the context of e-commerce. The relationships among privacy, risk, trust and internet security measures are empirically investigated to predict the behavioral intention to take part in e-commerce. Theoretical contributions and implications are discussed
A Tonal Analysis of Gurung, with Separate Systems for Register and Contour Pitch Features
An earlier analysis of Gurung, by Burton-Page in BSOAS, 17/1, 1955, put forward a single system, of two terms, for the word unit in the dialect spoken in Ghandrung: tones 1 and 2; the present analysis of the Gurung of a speaker from the centre of the Gurung area differs from Burton-Page's in that it distinguishes two tone systems: a two-term system (tones 1 and 2) for a difference in pitch register and a further two-term system (tones A and B) for a difference in pitch contour. Support for separating register-pitch and contour-pitch differences comes from three associated features, aspiration, phonation and voice: they apply to the register distinction but not to the contour distinction. Further support comes from comparing this tonal analysis with an identical analysis of a closely related language, Tamang, and also with the two-term system put forward for the word in Tibetan
Identification of cyclin D3 as a new interaction partner of lamin A/C
Lamin A/C is a major component of the nuclear lamina. An intact nuclear lamina has been proposed to be necessary for muscle differentiation. Cyclin D3 is known to be upregulated in differentiated muscle cells and to form insoluble complexes with cell-cycle regulatory factors in these cells. We have examined the possibility of direct binding interactions between lamin A/C and cyclin D3 by in vitro binding assays and co-immunoprecipitation studies with muscle cells. Our results indicate that cyclin D3 binds specifically to amino acid residues 383–474 of lamin A/C and associates with lamin A/C in muscle cells. The identification of cyclin D3 as a novel binding partner of lamin A/C has important implications for a role for lamin A/C in muscle differentiation
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