Regulatory Impact of the C-Terminal Tail on Charge Transfer Pathways in Drosophila Cryptochrome

Interconnected transcriptional and translational feedback loops are at the core of the molecular mechanism of the circadian clock. Such feedback loops are synchronized to external light entrainment by the blue light photoreceptor cryptochrome (CRY) that undergoes conformational changes upon light absorption by an unknown photoexcitation mechanism. Light-induced charge transfer (CT) reactions in Drosophila CRY (dCRY) are investigated by state-of-the-art simulations that reveal a complex, multi-redox site nature of CT dynamics on the microscopic level. The simulations consider redox-active chromophores of the tryptophan triad (Trp triad) and further account for pathways mediated by W314 and W422 residues proximate to the C-terminal tail (CTT), thus avoiding a pre-bias to specific W-mediated CT pathways. The conducted dissipative quantum dynamics simulations employ microscopically derived model Hamiltonians and display complex and ultrafast CT dynamics on the picosecond timescale, subtly balanced by the electrostatic environment of dCRY. In silicio point mutations provide a microscopic basis for rationalizing particular CT directionality and demonstrate the degree of electrostatic control realized by a discrete set of charged amino acid residues. The predicted participation of CT states in proximity to the CTT relates the directionality of CT reactions to the spatial vicinity of a linear interaction motif. The results stress the importance of CTT directional charge transfer in addition to charge transfer via the Trp triad and call for the use of full-length CRY models including the interactions of photolyase homology region (PHR) and CTT domains.

Species selective charge transfer dynamics in a P3HT/MoS2 van der Waals heterojunction: fluorescence lifetime microscopy and core hole clock spectroscopy approaches

The π* (C–C) electronic state of the P3HT species is the main pathway for interfacial ultrafast CT in a P3HT/MoS2/SiO2 heterojunction.

Role of 256 slice CT scan in pre and postoperative evaluation of congenital cardio-vascular anomalies: our experience at a tertiary care teaching hospital

Background: Ultrafast CT (UCT) scan plays an important role in the evaluation of congenital cardiovascular anomalies (CCVA). A major advantage of higher slice multi-detector CT (MDCT), is improved temporal as well as spatial resolution, that helps accurately to delineate complex cardiac and extra-cardiac anomalies with relative ease. Hence this study was aimed to highlight the utility of UCT in the evaluation of congenital cardiovascular anomalies in a large series of patients.Methods: All consecutive patients with suspected CCVA were evaluated by cardiac CT angiography (CCTA) on 256 slice CT scan in a multispecialty tertiary care teaching institute from June 2013 to December2015.Results: A total of 160 cases of CCVA were evaluated by CCTA. 50 patients had multiple anomalies. A total of 216 anomalies were diagnosed. Tetralogy of fallot (TOF) dominated the list of CCVAs (60, 28%) than the other abnormalities. Of them, 25 patients underwent Blalock Taussig (BT) shunt surgeries, 20 patients underwent total repair operation like Rastelli’s operation or augmentation of pulmonary arteries (PAs) while 15 patients were lost to follow up. Most of the patients diagnosed with CCVAs were managed successfully based on the imaging diagnosis of the cardiovascular anomaly.Conclusions: Ultrafast CT scans have immense role in the evaluation of various types of congenital cardiovascular anomalies. It is particularly helpful in the evaluation of extra-cardiac systemic and pulmonary arterial and venous system, postoperative complications, to see the status of shunts, stents and conduits.

2D 7Li Ultrafast CT-COSY: a new tool for the rapid measurement of tiny homonuclear lithium scalar couplings

We report on the first examples of 7Li Ultrafast (UF) CT-COSY spectra from lithiated samples and on the usefulness of these experiments for the quantitative estimation of the 2J7Li–7Li in a much shorter time.