ABSTRACT
Dibrominated bis[1]benzothieno[3,2-b;2',3'-e][1,4]thiazines (BBTT) are efficiently synthesized and applied in Suzuki and Buchwald-Hartwig cross-coupling reactions to give access to 3,9-disubstituted BBTT derivatives with extended π-conjugation and enhanced electronic properties. For instance, 3,9-di(hetero)aryl substituted BBTT derivatives surpass their parent congeners phenothiazines with lower oxidation potentials and pronounced yellow to orange-red fluorescence (Φf ≈ 30-45%). In addition, 3,9-bis(di(hetero)arylamino substituted BBTT possess very high lying HOMO energy (EHOMO = -4.46 to -4.83 eV), a favorable property of hole transport molecules. A representative X-ray structure analysis reveals that the central BBTT core in these extended π-systems is essentially planarized. Upon protonation of a 3,9-bis(di(hetero)arylamino) substituted BBTT, the absorption color shifts from yellow to deep blue with a concomitant loss of the emission. The optical properties of these novel BBTT derivatives can be plausibly rationalized by time-dependent density functional theory (TD(DFT)) calculations and correlation between experimentally determined oxidation potentials and σp parameters as well as between photophysical data and the specific substituent parameter σp- by establishing electronic structure-property relationships.
ABSTRACT
Organisational competitive procurement environment positively impacts prices while supply side factors also determine participation in bidding. With strong competition costs come down. Instances of low competition in equipment purchase in the apex tertiary care hospital led to this study aimed at determining procurement practices, competition in procurement and its determinants. Review of tender records for three financial years (2011-2014) was conducted to ascertain procurement practices and resulting competition. Sellers' perspective on factors determining participation was captured through a questionnaire. Although four bids per tender were received only two qualified technically emphasising need for broad based specifications. Both sellers and peer staff also feel that specifications are not broad based. Regression analysis showed that one unit increase in bid led to six per cent price reduction. Increase in number of equipment led to an increase in the number of bids received but no price decrease. Pre-bid meetings have no effect on the price offered. Quality of tender document and feasible demonstration are modifiable bidding factors. Procuring agencies need to be transparent to reflect an organisationally supported competitive environment. The future research directions are interventional studies on specifications, pre-bid meetings and increasing transparency.
Subject(s)
Economic Competition , Costs and Cost Analysis , HumansABSTRACT
The management and expression of emotions can have a positive impact on psychological health and overall functioning. Thus, it is crucial to focus on the study of emotion regulation and the strategies young adults employ to achieve it, namely cognitive reappraisal and expressive suppression, as well as their associations with the long neglected psychosocial factors. The current study aimed at exploring the associations between psychosocial factors and the two emotion-regulation strategies, after controlling for potential sociodemographic confounders. This study used a sample of 136 participants from the Indian subcontinent living in Dubai, United Arab Emirates, aged 18-25 years, who completed instruments measuring social anxiety, social support, and parenting styles (authoritative, authoritarian, permissive) as well as the use of the emotion-regulation strategies of suppression and reappraisal. The results indicated that having experienced authoritarian parenting and perceiving low social support were associated with the use of suppression, while having experienced authoritative parenting and low levels of social anxiety were associated with the use of emotional reappraisal. Our study provides evidence on the importance of psychosocial factors for the use of emotion-regulation strategies and suggests their modification for the promotion of adaptive ways of managing emotions.
