Correlative Microscopy: A Potent Tool for Biomedicine

The correlative microscopy method based on a combination of optical and electronic techniques that is increasingly widely used now, has a number of limitations. Here, an alternative approach is considered that uses scanning probe microscopy (SPM) technique to get high-resolution and ultra-high-resolution data. SPM greatly increases the possibilities of collecting new information (on topological, morphological, electrical, magnetic etc. properties). To obtain three-dimensional distributions of different parameters of the sample, ultramicrotomography is used, which allows to scan the sample in steps of up to 20 nm. The principal advantage of the approach is that spectral data are used which due to the combination in near field microscopy can be gained with high and ultrahigh resolution. All above mentioned features are implemented in a single instrument, which allows to have 3-D data and their distributions at the same instrumental platform. A special feature of the approach is the possibility to use all the power of micro(nano)spectral methods. Therefore, it would be more correct to name the proposed approach ”Correlative microspectroscopy”. Keywords: correlative microscopy, correlative microspectroscopy, scanning near-ielf optical microscopy, ultramicrotomography, Raman, TER

Design of the Model of Ratiometric Polymer Nanobiothermometer Based on Quantum Dots

To solve many modern biological and biotechnological tasks it is necessary to realize strictly control and regulation of temperature of the cells and their organelles. Thi stasks include control of various exo- and endothermic reactions, monitoring of tissues‘ and individual cell‘s temperature in in vitro researches and in vivo procedures such as the hyperthermia procedure that used for cancer treatment. The today known methods of measuring and controlling of temperature at the cellular level can not provide the necessary level of locality and accuracy due to too big size and heightened sensitivity to external factors. The real alternative of existing today methods is nanoscale temperature biosensor operating on a ratiometric principle and based on the composite structure from polymers and colloidal quantum dots. In this paper we present a working model and plan of investigation of ratiometric nanoscale polymer nanobiothermometer based on quantum dots. Keywords: thermosensors, quantum dots, local temperature, polymers, temperature measuremen

Technology for Creation and Detailed Analysis of Polymer Composites with Uniform Distribution of Quantum Dots and Liquid Crystals

One of the most actual tasks in biotechnology is the creation of a new generation of nanobiosensors with improved brightness, photo stability, and sensitivity. Compositions of polymers and colloidal quantum dots (QDs) are the most promising base to develop such sensors. This work presents the technology for creation and detailed analysis of nanostructured composite films based on polypropylene matrices with uniformly distributed CdSe/ZnS quantum dots and liquid crystals. Methods of optical microscopy, scanning probe microscopy and confocal fluorescen tmicrospectroscopy were used. The presence of liquid crystals in the composite allows additional control of QDs fluorescence. The methodology proposed is applicable not only to polypropylene, but also to other porous polymers. The results of this work indicate the possibility of creating high-quality polymer/QDs composite materials and open the way to the development of nanomaterials (nanosensors) with optical properties sensitive to various environmental parameters (electric field, photo irradiation, mechanical action, etc.). Keywords: quantum dot-polymer composites, nanoporous polypropylene, fluorescenc

Evaluation of interspecific populations of grapevine in breeding for complex resistance to fungal diseases and phylloxera

Roentgenoscopy was used as a method to determine the quality of hybrid seeds and to predict the development of viable plants from interspecific hybridization. The seeds were grouped into five classes of quality (embryo classes) depending on embryo size and degree of endosperm development As the index number of a class increased, the proportion of plantlets and vigorous plants produced also increased. In order to evaluate genotypic peculiarities of the original forms and seedlings, the seedlings were studied at the juvenile stage of ontogeny. Analysis of development of the hybrids studied during 5-6 years under conditions of complex infection pressure at a special planting site made it possible to evaluate the degree of their resistance to phylloxera, pathogenic soil microflora and fungal diseases and to eliminate susceptible genotypes. The heritability of resistance to fungal diseases (mildew, oidium, grey rot) and phylloxera was studied, conclusions were made concerning the combining ability of the original forms, and these forms were evaluated as donors of the desirable characters. Using transgressive resistant hybrids as donors in backcrossing provided improved quality with a broad range of resistance variability, which made it possible to select promising genotypes

Resonance energy transfer in self-organized organic/inorganic dendrite structures

Hybrid materials formed by semiconductor quantum dots and J-aggregates of cyanine dyes provide a unique combination of enhanced absorption in inorganic constituents with large oscillator strength and extremely narrow exciton bands of the organic component. The optical properties of dendrite structures with fractal dimension 1.7–1.8, formed from J-aggregates integrated with CdTe quantum dots (QDs), have been investigated by photoluminescence spectroscopy and fluorescence lifetime imaging microscopy. Our results demonstrate that (i)J-aggregates are coupled to QDs by F¨orster-type resonant energy transfer and (ii) there are energy fluxes from the periphery to the centre of the structure, where the QD density is higher than in the periphery of the dendrite. Such an anisotropic energy transport can be only observed when dendrites are formed from QDs integrated with J-aggregates. These QD/ J-aggregate hybrid systems can have applications in light harvesting systems and optical sensors with extended absorption spectra.Fundação para a Ciência e a Tecnologia (FCT

A Plasma Survey Using 38 PfEMP1 Domains Reveals Frequent Recognition of the Plasmodium falciparum Antigen VAR2CSA among Young Tanzanian Children

PfEMP1 proteins comprise a family of variant antigens that appear on the surface of P. falciparum-infected erythrocytes and bind to multiple host receptors. Using a mammalian expression system and BioPlex technology, we developed an array of 24 protein constructs representing 38 PfEMP1 domains for high throughput analyses of receptor binding as well as total and functional antibody responses. We analyzed the reactivity of 561 plasma samples from 378 young Tanzanian children followed up to maximum 192 weeks of life in a longitudinal birth cohort. Surprisingly, reactivity to the DBL5 domain of VAR2CSA, a pregnancy malaria vaccine candidate, was most common, and the prevalence of reactivity was stable throughout early childhood. Reactivity to all other PfEMP1 constructs increased with age. Antibodies to the DBL2βC2PF11_0521 domain, measured as plasma reactivity or plasma inhibition of ICAM1 binding, predicted reduced risk of hospitalization for severe or moderately severe malaria. These data suggest a role for VAR2CSA in childhood malaria and implicate DBL2βC2PF11_0521 in protective immunity

Development of a molecular-based index for assessing iron status in bloom-forming pennate diatoms

Iron availability limits primary productivity in large areas of the world's oceans. Ascertaining the iron status of phytoplankton is essential for understanding the factors regulating their growth and ecology. We developed an incubation-independent, molecular-based approach to assess the iron nutritional status of specific members of the diatom community, initially focusing on the ecologically important pennate diatom Pseudo-nitzschia. Through a comparative transcriptomic approach, we identified two genes that track the iron status of Pseudo-nitzschia with high fidelity. The first gene, ferritin (FTN), encodes for the highly specialized iron storage protein induced under iron-replete conditions. The second gene, ISIP2a, encodes an iron-concentrating protein induced under iron-limiting conditions. In the oceanic diatom Pseudo-nitzschia granii (Hasle) Hasle, transcript abundance of these genes directly relates to changes in iron availability, with increased FTN transcript abundance under iron-replete conditions and increased ISIP2a transcript abundance under iron-limiting conditions. The resulting ISIP2a:FTN transcript ratio reflects the iron status of cells, where a high ratio indicates iron limitation. Field samples collected from iron grow-out microcosm experiments conducted in low iron waters of the Gulf of Alaska and variable iron waters in the California upwelling zone verify the validity of our proposed Pseudo-nitzschia Iron Limitation Index, which can be used to ascertain in situ iron status and further developed for other ecologically important diatoms

Diagnosis of Cervical Cancer Using Raman Spectroscopy

The aim of the study was to develop a method of detecting cervical cancer using Raman spectroscopy in the examination of biopsy and surgical material. Significant differences in the spectral characteristics between the tissues of the intact cervix and tissues with squamous cell carcinoma of the cervix have been revealed. Intensity of fluorescence in cervical cancer was higher than in intact cervical tissue.     Keywords: cervical cancer, squamous cell carcinoma, diagnosis of cervical cancer, fluorescence in cervical cancer, Raman spectroscopy for the diagnosis of cervical cance

Neoglycolipids Micelle-like Structures as a Basis for Drug Delivery Systems

Targeted drug delivery is one of the most promising tasks of nanomedicine, as this is a real way to increase the effectiveness of therapeutic effects against many diseases. In this regard, the development of new inexpensive highly effective stimulating and non-immunogenic drug delivery systems (DDS) is of great importance. In this work new molecular candidates were proposed and studied for the creation of such systems based on the use of new compounds, neoglycolipids. It is shown that these compounds are capable of self-association in aqueous solutions and can serve as potential carriers of drug compounds with targeted delivery determined by their terminal groups (in particular, glycans). The processes of their associates formation and features of their structure are investigated. The results show that these selforganizing nanoscale systems can be used as a basis for developing new drug delivery systems. Keywords: neoglycolipids, micelle-like structures, small-angle X-ray scattering, molecular dynamics simulatio

Evaluating the Effectiveness of the Original Designs of Immediate-Prostheses after Multiple Tooth Extraction: Clinical Cases

Background. Rehabilitation of patients with chronic periodontal diseases leading to multiple tooth loss can be carried out using the method of immediate prosthetics. However, the likelihood of atrophy of denture-supporting tissues under non-physiological load with removable dental prostheses imposes special requirements for their design features.Case description. Two patients seeking for dental surgical and prosthetic treatment for the diagnosis of chronic generalized periodontitis were treated in the dental clinic of Ryazan State Medical University named after academician I.P. Pavlov. Patient A. was mounted immediate prostheses made using additive technologies with the original design of the drug reservoir. Patient B. was mounted immediate prostheses with bases made of acrylic plastic, border ring of elastic polymer, and a drug reservoir made of polymethyl methacrylate. Patients underwent tooth extraction with immediate prosthetics. Patients were followed for 21 days. Criteria for the effectiveness of treatment included visual and palpatory control of extraction sites with a planimetric wound size analysis, assessment of microcirculation at the extraction site, control of the drug persistence in the reservoirs of prostheses.Conclusion. The observations at the stages of prosthodontic treatment revealed that immediate prostheses made with the help of 3D modeling and printing technologies resulted in a normal course of healing after tooth extraction with the normalization of microcirculatory parameters at the surgical wound sites. When using combined prosthetic structures, healing of postoperative wounds also proceeded favorably, however, congestion in the microcirculatory system was noted