Improving the system of preventing vibration and noise-induced pathology

Due to the long-term study of various machines under industrial and test conditions it became possible to determine the specific role of each chain of the man-machine system in the intensification of vibroacoustic effect on a worker and to develop a system of medical, technical and organizational preventive measures. Introduction of a set of such measures at one of the plants helped to reduce vibration disease rates by dozens of times. In order to control noise- and vibration-caused diseases it was necessary not only to improve machines' quality and service conditions but also to pay special attention to the choice of operators and to the quality of monitoring their adaptation process.     

Serotonergic,Brain Volume and Attentional Correlates of Trait Anxiety in Primates

Trait anxiety is a risk factor for the development and maintenance of affective disorders, and insights into the underlying brain mechanisms are vital for improving treatment and prevention strategies. Translational studies in non-human primates, where targeted neurochemical and genetic manipulations can be made, are critical in view of their close neuroanatomical similarity to humans in brain regions implicated in trait anxiety. Thus, we characterised the serotonergic and regional brain volume correlates of trait-like anxiety in the marmoset monkey. Low- and high-anxious animals were identified by behavioral responses to a human intruder (HI) that are known to be sensitive to anxiolytic drug treatment. Extracellular serotonin levels within the amygdala were measured with in vivo microdialysis, at baseline and in response to challenge with the selective serotonin reuptake inhibitor, citalopram. Regional brain volume was assessed by structural magnetic resonance imaging. Anxious individuals showed persistent, long-term fearful responses to both a HI and a model snake, alongside sustained attention (vigilance) to novel cues in a context associated with unpredictable threat. Neurally, high-anxious marmosets showed reduced amygdala serotonin levels, and smaller volumes in a closely connected prefrontal region, the dorsal anterior cingulate cortex. These findings highlight behavioral and neural similarities between trait-like anxiety in marmosets and humans, and set the stage for further investigation of the processes contributing to vulnerability and resilience to affective disorders.     

Parameter Identification of Cutting Forces in Crankshaft Grinding Using Artificial Neural Networks

The intensifying of the manufacturing process and increasing the efficiency of production planning of precise and non-rigid parts, mainly crankshafts, are the first-priority task in modern manufacturing. The use of various methods for controlling the cutting force under cylindrical infeed grinding and studying its impact on crankpin machining quality and accuracy can improve machining efficiency. The paper deals with developing a comprehensive scientific and methodological approach for determining the experimental dependence parameters’ quantitative values for cutting-force calculation in cylindrical infeed grinding. The main stages of creating a method for conducting a virtual experiment to determine the cutting force depending on the array of defining parameters obtained from experimental studies are outlined. It will make it possible to get recommendations for the formation of a valid route for crankpin machining. The research’s scientific novelty lies in the developed scientific and methodological approach for determining the cutting force, based on the integrated application of an artificial neural network (ANN) and multi-parametric quasi-linear regression analysis. In particular, on production conditions, the proposed method allows the rapid and accurate assessment of the technological parameters’ influence on the power characteristics for the cutting process. A numerical experiment was conducted to study the cutting force and evaluate its value’s primary indicators based on the proposed method. The study’s practical value lies in studying how to improve the grinding performance of the main bearing and connecting rod journals by intensifying cutting modes and optimizing the structure of machining cycles.     

Selective early cardiolipin peroxidation after traumatic brain injury: an oxidative lipidomics analysis

OBJECTIVE: Enhanced lipid peroxidation is well established in traumatic brain injury. However, its molecular targets, identity of peroxidized phospholipid species, and their signaling role have not been deciphered. METHODS: Using controlled cortical impact as a model of traumatic brain injury, we employed a newly developed oxidative lipidomics approach to qualitatively and quantitatively characterize the lipid peroxidation response. RESULTS: Electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry analysis of rat cortical mitochondrial/synaptosomal fractions demonstrated the presence of highly oxidizable molecular species containing C(22:6) fatty acid residues in all major classes of phospholipids. However, the pattern of phospholipid oxidation at 3 hours after injury displayed a nonrandom character independent of abundance of oxidizable species and included only one mitochondria-specific phospholipid, cardiolipin (CL). This selective CL peroxidation was followed at 24 hours by peroxidation of other phospholipids, most prominently phosphatidylserine, but also phosphatidylcholine and phosphatidylethanolamine. CL oxidation preceded appearance of biomarkers of apoptosis (caspase-3 activation, terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positivity) and oxidative stress (loss of glutathione and ascorbate). INTERPRETATION: The temporal sequence combined with the recently demonstrated role of CL hydroperoxides (CL-OOH) in in vitro models of apoptosis suggest that CL-OOH may be both a key in vivo trigger of apoptotic cell death and a therapeutic target in experimental traumatic brain injury.