Elasticity of polyelectrolyte multilayer microcapsules

We present a novel approach to probe elastic properties of polyelectrolyte multilayer microcapsules. The method is based on measurements of the capsule load-deformation curves with the atomic force microscope. The experiment suggests that at low applied load deformations of the capsule shell are elastic. Using elastic theory of membranes we relate force, deformation, elastic moduli, and characteristic sizes of the capsule. Fitting to the prediction of the model yields the lower limit for Young's modulus of the polyelectrolyte multilayers of the order of 1-100 MPa, depending on the template and solvent used for its dissolution. These values correspond to Young's modulus of an elastomer

Biostability of cotton fibers with different natural colors and selection

ArticleBiodamageability is one of the weak sides of the cotton - plant fiber. Economic loss from the cotton damage caused by microorganisms is significant. Toxic chemical compounds are used to preserve the cotton fiber. This has a negative impact on environment and cotton consumer s. The degree of the cotton biodamage depends on selection variety, types of cultivation, storage conditions and other factors. One of the directions in cotton planting is selection of the boll - stained cotton. It was established that naturally colored cott on of different varieties has high biostability. It allows to product hypoallergenic, eco - friendly textile and reduces impact on the environment. The purpose of the work is stability evaluation for microbiological damage of different cotton varieties inclu ding those naturally colored during long - term storage in different temperature and humidity conditions. The research lasted for 10 years. The species composition of the cotton microflora was determined, the impact of fiber on microorganisms and dynamics of samples biodamage was studied in the work. The results obtained show preservation of microflora viability on cotton fiber when storing it under normal conditions for a long - term period. With an increase in temperature and humidity necessary for microorgan isms’ growth, the fiber destruction processes are amplified. It was established that cotton damage degree depends on the regimes and terms of its storage as well as the color of the fiber. Nature - colored cotton is more resistant for microorganisms, some va rieties inhibit the growth of mold fungi

Young's modulus of polyelectrolyte multilayers from microcapsule swelling

We measure Young's modulus of a free polyelectrolyte multilayer film by studying osmotically induced swelling of polyelectrolyte multilayer microcapsules filled with the polyelectrolyte solution. Different filling techniques and core templates were used for the capsule preparation. Varying the concentration of the polyelectrolyte inside the capsule, its radius and the shell thickness yielded an estimate of an upper limit for Young's modulus of the order of 100 MPa. This corresponds to an elastomer and reflects strong interactions between polyanions and polycations in the multilayer

Intracortical Dentate Fascia Grafts: Mossy Fiber Synapses in the Host Neocortex

Embryonic dentate fascia was grafted into a cavity in the area of the adult rat neocortex which represents the vibrissae (barrel field). We wished to test the possibility of development of connections between the two brain areas which do not have synaptic or tissue contacts in situ The unique characteristics of the giant synaptic boutons of the dentate mossy fibers were used for detection of the dentate synaptic contacts with neocortical neurons at the electron microscopic level. Ultrastructural analysis nine months postgrafting has shown that the bundles of mossy axons eter the host neocortex and develop multiple terminal and en passant contacts with typical characteristics. Neuronal perikarya, large dendritic trunks and fine caliber terminal dendritic branches were used by the mossy fibers as postsynaptic targets, as well as spines of various complexity and configurations. The subsynaptic dendrites seemed to be modified by synapsing giant boutons. Accumulation of cytoplasmic organelles was observed at these sites. Various bumps and protuberances were formed by the subsynaptic dendrite surface. The contents of these appendages were variable; some of them contained organeiles typical of dendroplasm, while others were more spine-like, often with inclusion of ribosomes. It is concluded that mossy fibers growing into the host neocortex can develop typical contacts with inappropriate targets with all the ultrastructural features of functional synapses

Social and economic space compression in border areas: the case of the Northwestern Federal District

The so-called "compression" of social and economic space has been the subject of quite a few studies in the past decades. There are two principle types of compression: communicative, that is, associated with the development of transport and information systems, and physical, manifested in the rapid decrease of the number of new territories to explore. While physical and communicative compression are interrelated, they have different spatial expressions depending on geographical conditions, economic, environmental, historical, and political characteristics of the region. The authors identify the patterns of communicative and physical space compression using comparative mapping, statistical and historical research methods, and a model showing the spatial differentiation of regional socioeconomic characteristics in the Northwestern Federal District. The study focuses on border areas, where the following key manifestations of compression have been identified: transport connectivity, level of agriculture development, and depopulation. All these indicators of space compression process are studied at the municipal level. The authors identify the key features of socioeconomic space compression for the border areas of the Russian Northwest

Application of Crowdsourcing Technology In Terms Of Digitization of Supply Chain Strategy

Abstract— The article presents the study on the problem of crowdsourcing application in terms of digital development of supply chain strategy. The purpose of this study is to develop the algorithm of application of crowdsourcing technology in terms of digitalization of supply chain strategy in socio-economic processes. The application of crowdsourcing technology facilitates the search for the most effective solutions to enterprise’s problems, minimizing the time-related and financial costs for their development. In the framework of this study, the methods of analysis, comparative analysis, generalization, decomposition were used. The novelty of the research is in the detailed examination of the crowdsourcing technology, comprehensive description of the algorithm of its functioning with application in addressing various tasks of supply chain strategy. The findings of the study can help enterprises to elaborate the workflow supply chain management with regard to public opinion

Quantitative Estimation of the Ratio of GABA-Immunoreactive Cells in Neocortical Grafts

Somatosensory anlage from 17-18 day old rat embryos were transplanted in place of the removed barrel cortex in adult rats. Six to eight months after transplantation, the grafts were either completely separated by glial scar or partly separated and partly confluent with the host neocortex. Each was studied histologically and immunostained for GABA. It was found that in partly confluent grafts the neuronal density was similar or even higher than in the host cortex, while the cell number in the separate grafts was much lower than in the nearby host cortex. The number of GABA-positive cells, however, was in all grafts significantly lower (2.9% on average) than in the normal cortex (11.8% on average).The decline in GABA-stained nerve cells was highest in separated grafts, but was somewhat less marked in transplants partly confluent with the host tissue. The possible role of partial or total deafferentation as well as the relative vulnerability of the transplanted tissue by temporary hypoxia and other metabolic disturbances are discussed as the probable factors in selective decline of GABA-ergic cells in the transplanted somatosensory cortex

Age-Related Loss of GABA-Positive and GABA-Negative Neurons in Neocortical Transplants

The numerical density of GABA immunopositive and GABA immunonegative neurons was quantitatively determined in 0, 12, 30 and 90 day-old neocortical transplants, derived from E17 rat embryos and transplanted into adult hosts. It was found that the original, very high neuronal density in the fetal transplant declined steadily after transplantation to the somatosensory cortex of adult rat. The decline in numerical density of GABA-positive neurons, however, was disproportionately larger than that of GABA-negative nerve cells: At 90 days the proportion of GABA-positive cells was 2.3% (in contrast to the 11.8% in the adult host cortex). The density of GABA-negative neurons, on the other hand, remained slightly higher than comparable values in the control cortex. The decline in density Of GABA-positive neurons was continuous until the 90th post-transplantation day, while final, close to normal density values of GABA-negative nerve cells were already reached in 30 day-old grafts, with no significant change afterwards

Nonlinear acoustic waves in channels with variable cross sections

The point symmetry group is studied for the generalized Webster-type equation describing non-linear acoustic waves in lossy channels with variable cross sections. It is shown that, for certain types of cross section profiles, the admitted symmetry group is extended and the invariant solutions corresponding to these profiles are obtained. Approximate analytic solutions to the generalized Webster equation are derived for channels with smoothly varying cross sections and arbitrary initial conditions.Comment: Revtex4, 10 pages, 2 figure. This is an enlarged contribution to Acoustical Physics, 2012, v.58, No.3, p.269-276 with modest stylistic corrections introduced mainly in the Introduction and References. Several typos were also correcte

Certain reactions of 2,2,2-trialkoxy-Δ4-oxaphospholenes

1. β-(Dimethylphosphono)propionaldehyde was obtained by hydrolysis of 2,2,2-trimethoxy-Δ4-oxaphospholene. 2. Upon reaction of 2,2,2-trimethoxy-Δ4-oxaphospholene with acetic acid and acetic anhydride, opening of the phosphorane ring occurs of the P-O bond with for mation of β-(dimethylphosphono)propionaldehyde and its enol acetate, respectively. © 1969 Consultants Bureau