Altered Membrane Mechanics Provides a Receptor-Independent Pathway for Serotonin Action

Serotonin, an important signaling molecule in humans, has an unexpectedly high lipid membrane affinity. The significance of this finding has evoked considerable speculation. Here we show that membrane binding by serotonin can directly modulate membrane properties and cellular function, providing an activity pathway completely independent of serotonin receptors. Atomic force microscopy shows that serotonin makes artificial lipid bilayers softer, and induces nucleation of liquid disordered domains inside the raft-like liquid-ordered domains. Solid-state NMR spectroscopy corroborates this data at the atomic level, revealing a homogeneous decrease in the order parameter of the lipid chains in the presence of serotonin. In the RN46A immortalized serotonergic neuronal cell line, extracellular serotonin enhances transferrin receptor endocytosis, even in the presence of broad-spectrum serotonin receptor and transporter inhibitors. Similarly, it increases the membrane binding and internalization of oligomeric peptides. Our results uncover a mode of serotonin–membrane interaction that can potentiate key cellular processes in a receptor-independent fashion.     

Unique rate expression for glucose production in C(4) plants

A physicochemical interpretation of a recently formulated temperature-dependent, steady-state rate expression for the production of glucose equivalent in C(4) plants is given here. We show that the rate equation is applicable to a wide range of C(4) plants.     

Unique bonding pattern and resulting bond stretch isomerism in

The bond‐stretch isomers are characterized by a principal change in the bond‐length with the rest of the molecule being unaltered. The electronic structure regulates the bond stretch isomerism phenomenon in which has been investigated with density functional theory, ab initio CASSCF, highly efficient n‐electron valence state perturbation theory and multireference configuration interaction calculations. Two isomers are distinguished on different potential energy surfaces and the corresponding avoided crossing is also studied in details. The bonding pattern in two isomers are analysed through adaptive natural density partitioning analysis and quantum theory of atoms in molecules analysis. The bonds in both the isomers primarily involve the 2p orbitals, which overlap face‐to‐face in long‐bond isomer. Whereas, in‐plane π‐bonding occurs at the short‐bond isomer leading to unusual bent bond. © 2015 Wiley Periodicals, Inc.     

Interaction between coherent structures and surface temperature and its effect on ground heat flux in an unstably stratified boundary layer

Surface layer plumes, thermals, downdrafts and roll vortices are the most prominent coherent structures in an unstably stratified boundary layer. They contribute most of the temperature and vertical velocity variance, and their time scales increase with height. The effects of these multi-scale structures (surface layer plumes scale with surface layer depth, thermals scale with boundary layer height and the resulting roll vortices scale with convective time scale) on the surface temperature and ground heat flux were studied using turbulence measurements throughout the atmospheric boundary layer and the surface temperature measurements from an infrared camera. Plumes and thermals imprint on the surface temperature as warm structures and downdrafts imprint as cold structures. The air temperature trace shows a ramp-like pattern, with small ramps overlaid on a large ramp very close to the surface; on the other hand, surface temperature gradually increases and decreases. Turbulent heat flux and ground heat flux show similar patterns, with the former lagging the latter. The maximum values of turbulent heat flux and ground heat flux are 4 and 1.2 times the respective mean values during the ejection event. Surface temperature fluctuations follow a similar power-law exponent relationship with stability as suggested by surface layer similarity theory.     

Thiourea dioxide (TUD): a robust organocatalyst for oxidation of sulfides to sulfoxides with TBHP under mild reaction conditions

Thiourea dioxide (TUD) has been reported for the first time as a highly efficient and selective organocatalyst for the oxidation of sulfides to sulfoxides in high to excellent yields by using tert-butylhydroperoxide as oxidant under mild reaction conditions.     

Highly twisted arenes by Scholl cyclizations with unexpected regioselectivity

Let's twist! The Scholl reaction with quinquephenyl derivatives has been shown to have an unexpectedly strong preference for forming twisted, helicene aromatic polycycles, instead of their flat counterparts. This tendency is so strong that it will overcome even severe steric hindrance, and the procedure can be used in the efficient synthesis of hexa-tert-butylhexabenzotriphenylene from a simple biaryl starting material (see scheme).     

Ionic liquid catalysed reaction of thiols with α,β-unsaturated carbonyl compounds--remarkable influence of the C-2 hydrogen and the anion

Hydrogen bond induced reactivity and selectivity control in the 1-butyl-3-methylimidazolium based ionic liquid catalysed reaction of thiols with α,β-unsaturated carbonyl compounds is reported with remarkable influence of the anion and the C-2 hydrogen in catalytic activity and reversal of selectivity.     

NOR and NAND gates using two photon absorption in silicon wire waveguide

Ultrafast all-optical NOR gate based on two photon absorption (2PA) process in SOI waveguide is already established. We have designed NAND gate also based on this process with a novel waveguide coupler structure. Power attenuation due to 2PA process and the working of these gates is developed with FDTD simulation. Dominant 2PA process is incorporated in FDTD update equations and it is shown that the influence of high intensity pump pulses on a different frequency continuous probe beam can be utilized to form NOR as well as NAND gates.     

On the group-theoretic structure of a class of quantum dialogue protocols

A sufficient condition for implementation of the quantum dialogue protocol is obtained and it is shown that the set of unitary operators used for the purpose must form a group under multiplication. A generalized protocol of quantum dialogue is obtained using the sufficient condition. Further, several examples of possible groups of unitary operators and quantum states that may be used for implementation of quantum dialogue are systematically generated. As examples, it is shown that GHZ state, GHZ-like state, W state, 4 and 5-qubit Cluster states, Ω   state, Brown state, _Q4$Q_4$ state and _Q5$Q_5$ state can be used to implement quantum dialogue protocol. It is also shown that if a quantum system is found to be suitable for quantum dialogue then that can provide solution of the socialist millionaire problem too.