Modulation of corticospinal activity by strong emotions evoked by pictures and classical music: a transcranial magnetic stimulation study.

Using transcranial magnetic stimulation and skin conductance responses, we sought to clarify if, and to what extent, emotional experiences of different valences and intensity activate the hand-motor system and the associated corticospinal tract. For that purpose, we applied a newly developed method to evoke strong emotional experiences by the simultaneous presentation of musical and pictorial stimuli of congruent emotional valence. We uncovered enhanced motor-evoked potentials, irrespective of valence, during the simultaneous presentation of emotional music and picture stimuli (Combined conditions) compared with the single presentation of the two modalities (Picture/Music conditions). In contrast, vegetative arousal was enhanced during both the Combined and Music conditions, compared with the Picture conditions, again irrespective of emotional valence. These findings strongly indicate that arousal is a necessary, but not sufficient, prerequisite for triggering the motor system of the brain. We offer a potential explanation for this discrepant, but intriguing, finding in the paper.

Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants

Climate models predict more frequent and more severe extreme events (e.g., heat waves, extended drought periods, flooding) in many regions for the next decades. The impact of adverse environmental conditions on crop plants is ecologically and economically relevant. This review is focused on drought and heat effects on physiological status and productivity of agronomically important plants. Stomatal opening represents an important regulatory mechanism during drought and heat stress since it influences simultaneously water loss via transpiration and CO2 diffusion into the leaf apoplast which further is utilized in photosynthesis. Along with the reversible short-term control of stomatal opening, stomata and leaf epidermis may produce waxy deposits and irreversibly down-regulate the stomatal conductance and non-stomatal transpiration. As a consequence photosynthesis will be negatively affected. Rubisco activase—a key enzyme in keeping the Calvin cycle functional—is heat-sensitive and may become a limiting factor at elevated temperature. The accumulated reactive oxygen species (ROS) during stress represent an additional challenge under unfavorable conditions. Drought and heat cause accumulation of free amino acids which are partially converted into compatible solutes such as proline. This is accompanied by lower rates of both nitrate reduction and de novo amino acid biosynthesis. Protective proteins (e.g., dehydrins, chaperones, antioxidant enzymes or the key enzyme for proline biosynthesis) play an important role in leaves and may be present at higher levels under water deprivation or high temperatures. On the whole plant level, effects on long-distance translocation of solutes via xylem and phloem and on leaf senescence (e.g., anticipated, accelerated or delayed senescence) are important. The factors mentioned above are relevant for the overall performance of crops under drought and heat and must be considered for genotype selection and breeding programs.

Cirrhotic cardiomyopathy: A cardiologist’s perspective

Cardiac dysfunction is frequently observed in patients with cirrhosis, and has long been linked to the direct toxic effect of alcohol. Cirrhotic cardiomyopathy (CCM) has recently been identified as an entity regardless of the cirrhosis etiology. Increased cardiac output due to hyperdynamic circulation is a pathophysiological hallmark of the disease. The underlying mechanisms involved in pathogenesis of CCM are complex and involve various neurohumoral and cellular pathways, including the impaired β-receptor and calcium signaling, altered cardiomyocyte membrane physiology, elevated sympathetic nervous tone and increased activity of vasodilatory pathways predominantly through the actions of nitric oxide, carbon monoxide and endocannabinoids. The main clinical features of CCM include attenuated systolic contractility in response to physiologic or pharmacologic strain, diastolic dysfunction, electrical conductance abnormalities and chronotropic incompetence. Particularly the diastolic dysfunction with impaired ventricular relaxation and ventricular filling is a prominent feature of CCM. The underlying mechanism of diastolic dysfunction in cirrhosis is likely due to the increased myocardial wall stiffness caused by myocardial hypertrophy, fibrosis and subendothelial edema, subsequently resulting in high filling pressures of the left ventricle and atrium. Currently, no specific treatment exists for CCM. The liver transplantation is the only established effective therapy for patients with end-stage liver disease and associated cardiac failure. Liver transplantation has been shown to reverse systolic and diastolic dysfunction and the prolonged QT interval after transplantation. Here, we review the pathophysiological basis and clinical features of cirrhotic cardiomyopathy, and discuss currently available limited therapeutic options.

Regulating a Benzodifuran Single Molecule Redox Switch via Electrochemical Gating and Optimization of Molecule/Electrode Coupling

We report a novel strategy for the regulation of charge transport through single molecule junctions via the combination of external stimuli of electrode potential, internal modulation of molecular structures, and optimization of anchoring groups. We have designed redox-active benzodifuran (BDF) compounds as functional electronic units to fabricate metal–molecule–metal (m–M–m) junction devices by scanning tunneling microscopy (STM) and mechanically controllable break junctions (MCBJ). The conductance of thiol-terminated BDF can be tuned by changing the electrode potentials showing clearly an off/on/off single molecule redox switching effect. To optimize the response, a BDF molecule tailored with carbodithioate (−CS2–) anchoring groups was synthesized. Our studies show that replacement of thiol by carbodithioate not only enhances the junction conductance but also substantially improves the switching effect by enhancing the on/off ratio from 2.5 to 8.

Highly-effective gating of single-molecule junctions: an electrochemical approach

We report an electrochemical gating approach with [similar]100% efficiency to tune the conductance of single-molecule 4,4′-bipyridine junctions using scanning-tunnelling-microscopy break junction technique. Density functional theory calculation suggests that electrochemical gating aligns molecular frontier orbitals relative to the electrode Fermi-level, switching the molecule from an off resonance state to “partial” resonance.