Potential of Antifungal Drugs as Photosensitizers

In the present work, using commercially available formulation of polyene antifungal antibiotic amphotericin B, it is shown that its antifungal activity could be enhanced in combination with optical radiation corresponding to the absorption band of amphotericin B due to photodynamic effect. It is assumed that the radical processes dominate in the mechanism of photodynamic action in the presence of amphotericin B. Keywords: Amphotericin B, antimicrobial/antifungal photodynamic therapy (aPDT), lactate dehydrogenase (LDH), singlet oxygen, laser, LED

Biological Effect of Continuous, Quasi-Continuous and Pulsed Laser Radiation

In this work, for the first time, comparative studies of biological activity of low intensity continuous, quasi-continuous and pulsed laser radiation of nano- and picosecond time ranges with the same average power density are carried out. It is shown, that, despite the significant differences in peak values of intensity of acting factor, both continuous and quasi-continuous radiation and radiation of nano- and picosecond ranges are able to have both stimulating and inhibiting effects on all investigated parameters of functional activity of biological systems in a certain range of dose rates. The ability of laser radiation of near infra-red spectral region (800 - 1340 nm) located out the absorption bands of main chromophores of cells to have regulatory effect on biochemical processes that control the hatching of branchiopod crustaceans Artemia salina L. upon irradiation of their cysts is revealed. The role of molecular oxygen and water as acceptors of laser radiation is discussed. Keywords: Low intensity laser radiation, Laser activation, Biological activity, Zooplankton Artemia salina L., Sturgeon sperm

Calculation of the stability of composite rods according to the non-classical bending model

The problem of the effect of deformations of transverse shear and transverse compression on the value of the critical stress in the problem of the loss of stability of a transversely isotropic rod is considered. The fourth-order differential equation of the nonclassical bending model of rods is applied. Formulas for the critical stress are obtained, as well as numerical results for rods made of different material

Comprehensive Study of Ni Nanotubes for Bioapplications: From Synthesis to Payloads Attaching

Due to the Ni nanotubes’ shape anisotropy, low specific density, large specific surface, and uniform magnetic field, they have been offered as carriers for targeted delivery of drug or protein and the process of their formation from synthesis stage to the stage of surface modification and protein attaching has been demonstrated. Some steps to hasten their biomedical application have been applied. First, to have full control over the carrier dimensions and structure parameters, electrodeposition method in pores of polyethylene terephthalate template has been applied. Second, to understand the scope of Ni nanostructures application, their degradation in media with different acidity has been studied. Third, to improve the biocompatibility and to make payloads attachment possible, nanotubes surface modification with organosilicon compound has been carried out. At last, the scheme of protein attaching to the nanostructure surface has been developed and the binding process was demonstrated as an example of the bovine serum albumin

Фотоиндуцированный дихроизм тонких пленок на основе бисазопроизводного салициловой кислоты и поливинилпирролидона

Using polyvinylpyrrolidone (PVP) as a polymer matrix for potassium 4,4-bis[1-(4-hydroxybutyl-3-carboxylate)phenylazo] biphenyl (ABA-2422) promotes trans-cis-isomerization and orientation of dye molecules on irradiation by linearly polarized light. Composite films based on ABA-2422 dispersed in PVP are optically anisotropic, have high dichroic ratio and low roughness.Методом центрифугирования сформированы многослойные композиционные пленки на основе калий 4,4'-бис[1-(4-оксибутил-3-карбоксилат)фенилазо]дифенила (АВА-2422), диспергированного в матрице поливинилпирро-лидона, и оптически прозрачного соолигомера стирола с циклогексадиеном (5:95 мас.°/о). Установлено, что фотоиндуцированная тран с -цис -изомеризация красителя в матрице ПВП протекает по реакции первого порядка с эффективной константой скорости kэфф.= 5,45 х 10-5 c-1. Композиционные пленки на основе АВА-2422 оптически анизотропны, характеризуются высоким дихроичным отношением и низкой шероховатостью

Sensing of minute airflow motions near walls using pappus-type nature-inspired sensors

This work describes the development and use of pappus-like structures as sensitive sensors to detect minute air-flow motions. We made such sensors from pappi taken from nature-grown seed, whose filiform hairs' length-scale is suitable for the study of large-scale turbulent convection flows. The stem with the pappus on top is fixated on an elastic membrane on the wall and tilts under wind-load proportional to the velocity magnitude in direction of the wind, similar as the biological sensory hairs found in spiders, however herein the sensory hair has multiple filiform protrusions at the tip. As the sensor response is proportional to the drag on the tip and a low mass ensures a larger bandwidth, lightweight pappus structures similar as those found in nature with documented large drag are useful to improve the response of artificial sensors. The pappus of a Dandelion represents such a structure which has evolved to maximize wind-driven dispersion, therefore it is used herein as the head of our sensor. Because of its multiple hairs arranged radially around the stem it generates uniform drag for all wind directions. While still being permeable to the flow, the hundreds of individual hairs on the tip of the sensor head maximize the drag and minimize influence of pressure gradients or shear-induced lift forces on the sensor response as they occur in non-permeable protrusions. In addition, the flow disturbance by the sensor itself is limited. The optical recording of the head-motion allows continuously remote-distance monitoring of the flow fluctuations in direction and magnitude. Application is shown for the measurement of a reference flow under isothermal conditions to detect the early occurrence of instabilities

Risky Decisions and Their Consequences: Neural Processing by Boys with Antisocial Substance Disorder

Adolescents with conduct and substance problems ("Antisocial Substance Disorder" (ASD)) repeatedly engage in risky antisocial and drug-using behaviors. We hypothesized that, during processing of risky decisions and resulting rewards and punishments, brain activation would differ between abstinent ASD boys and comparison boys.We compared 20 abstinent adolescent male patients in treatment for ASD with 20 community controls, examining rapid event-related blood-oxygen-level-dependent (BOLD) responses during functional magnetic resonance imaging. In 90 decision trials participants chose to make either a cautious response that earned one cent, or a risky response that would either gain 5 cents or lose 10 cents; odds of losing increased as the game progressed. We also examined those times when subjects experienced wins, or separately losses, from their risky choices. We contrasted decision trials against very similar comparison trials requiring no decisions, using whole-brain BOLD-response analyses of group differences, corrected for multiple comparisons. During decision-making ASD boys showed hypoactivation in numerous brain regions robustly activated by controls, including orbitofrontal and dorsolateral prefrontal cortices, anterior cingulate, basal ganglia, insula, amygdala, hippocampus, and cerebellum. While experiencing wins, ASD boys had significantly less activity than controls in anterior cingulate, temporal regions, and cerebellum, with more activity nowhere. During losses ASD boys had significantly more activity than controls in orbitofrontal cortex, dorsolateral prefrontal cortex, brain stem, and cerebellum, with less activity nowhere.Adolescent boys with ASD had extensive neural hypoactivity during risky decision-making, coupled with decreased activity during reward and increased activity during loss. These neural patterns may underlie the dangerous, excessive, sustained risk-taking of such boys. The findings suggest that the dysphoria, reward insensitivity, and suppressed neural activity observed among older addicted persons also characterize youths early in the development of substance use disorders