Modeling Electrolytically Top-Gated Graphene

We investigate doping of a single-layer graphene in the presence of electrolytic top gating. The interfacial phenomenon is modeled using a modified Poisson–Boltzmann equation for an aqueous solution of simple salt. We demonstrate both the sensitivity of graphene’s doping levels to the salt concentration and the importance of quantum capacitance that arises due to the smallness of the Debye screening length in the electrolyte.     

An investigation of myocardial aerobic capacity as a measure of both physical and cognitive workloads

With increased automation and supervisory control, the physical content of jobs has decreased while cognitive workload has increased. The cardiovascular system responds to both physical and cognitive stresses, and their combination, by causing an increase in both heart rate (HR) and blood pressure. The increase in HR and blood pressure cause an increase in myocardial contractility, which results in an increase in myocardial oxygen consumption (MV_O2). The rate–pressure product (RPP), given by the product of HR and systolic blood pressure, is a very reliable indirect measure of MV_O2. With this in mind, an experiment was conducted on 12 able-bodied male students from the University population. Subjects were required to perform three cognitive tasks (Stroop Incongruent Color-Word Test, simulated public speaking, and calculating task) under two physical conditions (riding a Schwinn Airdyne at a constant speed of 1/3 of their estimated maximum HR, and seated at rest on the Schwinn Airdyne). HR and blood pressure were monitored throughout the testing period. Results of the analysis of the randomized block design indicated that both cognitive and physical tasks had a significant effect on RPP. Additionally, the findings from this study indicated that RPP can be used as an objective measure to separate the components of cognitive workload and cognitive stress in combined tasks.

Relevance to industry

Rate–pressure product may be used as a measure of occupational workload, both cognitive and physical. It may be possible to use RPP measures to set limits on workloads and for establishing work allowance.     

Development of a novel cathodic plasma/electrolytic deposition technique: Part 2: Physico-chemical analysis of the plasma discharge

A novel plasma system has been developed recently for the deposition of carbon and titanium thin films on metal and metal alloy substrates. Unlike other deposition techniques, the process occurs in liquid precursors and a plasma discharge is created and confined around the cathode in a superheated vapour sheath surrounded by the liquid phase. This paper presents a detailed analysis of the physico-chemical mechanisms underlying this process. A correlation has then been carried out between the voltage/current characteristics and the consecutive physical phenomena occurring during the process (vapour phase formation, plasma discharge initiation and evolution). The structure and composition of the produced TiO₂ films have been compared with the composition and physical characteristics of the plasma discharge. This analysis allowed the construction of a first dissociation and deposition mechanism for this new plasma system.     

The possibility for obtaining sorbents from the mycelial wastes of antibiotic production

A technological process for production of a sorbent based on the mycelial waste of penicillin manufacture was developed. The process and its parameters are described. The exploitation conditions determine whether a strong sorbent with low sorption properties or a sorbent with higher sorption properties and lower granule strength is prepared.     

Chronic ethanol consumption: from neuroadaptation to neurodegeneration

In this review first we evaluate evidence on the role of the neurobiological alterations induced by chronic ethanol consumption in the development of ethanol tolerance, dependence and withdrawal. Secondly, we describe the neuropathological consequences of chronic ethanol on cognitive functions and on brain structures. Chronic alcohol consumption can induce alterations in the function and morphology of most if not all brain systems and structures. While tolerance mechanisms are unlikely to contribute to the neuroadaptive changes associated with ethanol dependence, it is otherwise clear that repeated high, intoxicating doses of ethanol trigger those neuroadaptive processes that lead to dependence and contribute to the manifestation of the abstinence syndrome upon withdrawal. An unbalance between inhibitory and excitatory neurotransmission is the most prominent neuroadaptive process induced by chronic ethanol consumption. Due to the diffuse glutamatergic innervation to all brain structures, the neuroadaptive alterations in excitatory neurotransmission can affect the function of most if not all of neurotransmitter systems. The expression of the withdrawal syndrome is the major causal factor for the onset and development of the neuropathological alterations. This suggests a link between the neuroadaptive mechanisms underlying the development of ethanol dependence and those underlying the functional and structural alterations induced by chronic ethanol. In animals and humans, specific alterations occur in the function and morphology of the diencephalon, medial temporal lobe structures, basal forebrain, frontal cortex and cerebellum, while other subcortical structures, such as the caudate nucleus, seem to be relatively spared. The neuropathological alterations in the function of mesencephalic and cortical structures are correlated with impairments in cognitive processes. In the brain of alcoholics, the prefrontal cortex and its subterritories seem particularly vulnerable to chronic ethanol, whether Korsakoff's syndrome is present or not. Due to the role of these cortical structures in cognitive functions and in the control of motivated behavior, functional alterations in this brain area may play an important role in the onset and development of alcoholism.     

A 3D-QSAR study on ginkgolides and their analogues with comparative molecular field analysis

Comparative molecular field analysis (CoMFA), a three-dimensional quantitative structure-activity relationship (3D-QSAR) paradigm was used to study the correlation between the physicochemical properties and the in vitro bioactivities of ginkgolide analogues. The correlation derived from CoMFA analysis has a good predictive capability. Based on the result of CoMFA analysis, we designed some compounds. Pharmacological assay indicated that three of these new designed compounds are 2 and 4 times more potent than that of ginkgolides.