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OBJECTIVE: Characteristics of the adhesion of yeast fungi and oral bacteria of various types in vitro to samples of polymeric materials for fixed structures of dental prostheses, obtained using various technologies: adjective digital 3D printing and traditional methods. MATERIAL AND METHODS: Conducted model experiments on the adhesion of bacterial (including the main periodontopic-pathogenic species - P. gingivalis, P. intermedia, etc.) and fungal pathogens (C. albicans) to standard samples of polymer materials NextDent C & B Micro Filled Hybrid («NextDent¼, Netherlands), Detax Freeprint temp UV («Detax¼, Germany), obtained by digital additive 3D printing technology, and Luxatemp Automix Plus («DMG¼, Germany) and Acrytemp («Zhermack¼, Italy) - by the traditional method as a control. Removal of adhering microbes from the material was carried out using an ultrasound machine (exposure time 10 minutes, power 60 kHz). RESULTS: The dependence of the degree of microbial adhesion on the nature of the material and processing technology (3D printing, milling) was established. The materials of NextDent C & B Micro Filled Hybrid and Detax Freeprint temp UV showed high resistance to adhesion of clinical isolates of periodontal pathogenic bacteria and C. albicans fungi. CONCLUSION: The lowest adhesion values for periodontopathogenic species and C. albicans fungi were detected when using samples of materials obtained by 3D printing: NextDent C & B Micro Filled Hybrid and Detax Freeprint temp UV compared to Luxatemp Automix Plus and Acrytemp polymers.
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Materiais Dentários , Polímeros , Bactérias , Biofilmes , Candida albicans , BocaRESUMO
BACKGROUND: The necessity of the comparative studies with special reference to the preconceptional preparation of the patients presenting with chronic endometritis is self-evident bearing in mind the lack of common approaches to the preconceptional preparation of the patients with this condition. AIMS: The objective of the present study was the evaluation of the effectiveness of preconceptional with the use phyto- and/or physiotherapies for the treatment of the patients suffering from chronic endometritis. MATERIAL AND METHODS: This prospective study included 309 patients from the couples in the infertile marriage attributable to chronic endometritis. All the patients were divided into three group depending on the choice of the preconceptional preparation modality. Those comprising the first group (n=148) received 2.5 mg in days the aqueous extract of one-sided-wintergreen (Orthilia secunda) at a daily dose of 2.5 mg during three months. The patients of the second group (n=101) were given the combined physiotherapeutic treatment. The patients of the third group (n=60) refused any preconceptional preparation; therefore an expectant strategy was chosen to manage them. Part of patients of the first and second groups (n=30) underwent the immunohistochemical investigation aimed at evaluation of the methods employed in this study to the solution of the infertility problem. The data obtained were treated with the use of the Statistica 11.0 software package. RESULT: The preconceptional preparation of the patients suffering infertility associated with chronic endometritis with the use of the aqueous extract of one-sided-wintergreen in the combination with physiotherapeutic treatment resulted in the development of pregnancy in 72.9% and 81.2% of the participants in the study respectively and its completion with labors in 95.3% and 90.1% of the women respectively. The results of the immunohistochemical study involving the patients treated with the aqueous extract of one-sided-wintergreen alone gave evidence of the reduced frequency of frequency of leukocytic infiltration and leukocytic activity in dynamics of an experiment (CD 20+, CD138+, CD 56+, CD 16+, HLA-DRII+); simultaneously, an augmentation of the reception of endometrium to sex steroids. CONCLUSION: The preconceptional preparation of infertile women with the application of the aqueous extracts of one-sided-wintergreen can be recommended for the patients with chronic endometritis, especially in the presence of contraindications for physiotherapy. Phytotherapy made use of in the present study restored reception of endometrium to estrogens and alleviated the autoimmune manifestations of local immunity.
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Endometrite/terapia , Modalidades de Fisioterapia , Fitoterapia , Extratos Vegetais/uso terapêutico , Doença Crônica , Endometrite/tratamento farmacológico , Endométrio/efeitos dos fármacos , Feminino , Humanos , Infertilidade Feminina , Gravidez , Estudos Prospectivos , Resultado do TratamentoRESUMO
The use of additive technologies in dentistry is a promising trend; however, the physical and mechanical properties of the materials intended for the fabrication of long-term fixed restorations remain understudied. The aim of this research is to determine the feasibility of the use of long-term fixed provisional restorations made of polymer materials, fabricated using 3D printing. The conformance of the physical and mechanical properties of NextDent C&B Micro Filled Hybrid (ND) and Detax Freeprint temp UV (DX) materials to ISO 1567:1999 standard, stability of their physical and mechanical properties under the conditions of accelerated aging, as well as their resistance to the oral cavity environment were studied. As a result of the performed studies, the DX material turned out to be superior to ND with respect to most characteristics. Clinical observations were conducted on the treatment of chronic generalized periodontitis using the following fixed provisional splints made of various materials: DX, fabricated according to the Slide-And-Separate technology, splints fabricated using the CAD/CAM technology, and adhesive splints reinforced with a GlasSpan fiberglass thread. As a result of the analysis of the OHI-S and PI indices values, the absence of any statistically significant difference between the above-describe treatment methods was determined. The studied materials conform to the requirements of ISO 1567:1999; the materials exhibited different stability under the conditions of accelerated aging, nevertheless, they can be utilized for the fabrication of long-term fixed provisional restorations.
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Desenho Assistido por Computador , Materiais Dentários/química , Planejamento de Prótese Dentária , Análise do Estresse Dentário/métodos , Polímeros/química , Vidro/químicaRESUMO
BACKGROUND AND PURPOSE: Tick-borne encephalitis (TBE) is an infection of the central nervous system (CNS) caused by tick-borne encephalitis virus (TBEV) and transmitted by ticks, with a variety of clinical manifestations. The incidence of TBE in Europe is increasing due to an extended season of the infection and the enlargement of endemic areas. Our objectives are to provide recommendations on the prevention, diagnosis and management of TBE, based on evidence or consensus decisions. METHODS: For systematic evaluation, the literature was searched from 1970 to 2015 (including early online publications of 2016), and recommendations were based on evidence or consensus decisions of the Task Force when evidence-based data were not available. RECOMMENDATIONS: Vaccination against TBE is recommended for all age groups above 1 year in highly endemic areas (≥5 cases/100 000/year), but also for individuals at risk in areas with a lower incidence. Travellers to endemic areas should be vaccinated if their visits will include extensive outdoor activities. Post-exposure prophylaxis after a tick bite is not recommended. A case of TBE is defined by the presence of clinical signs of meningitis, meningoencephalitis or meningoencephalomyelitis with cerebrospinal fluid (CSF) pleocytosis (>5 × 106 cells/l) and the presence of specific TBEV serum immunoglobulin M (IgM) and IgG antibodies, CSF IgM antibodies or TBEV IgG seroconversion. TBEV-specific polymerase chain reaction in blood is diagnostic in the first viremic phase but it is not sensitive in the second phase of TBE with clinical manifestations of CNS inflammation. Lumbar puncture should be performed in all patients with suspected CNS infection unless there are contraindications. Imaging of the brain and spinal cord has a low sensitivity and a low specificity, but it is useful for differential diagnosis. No effective antiviral or immunomodulating therapy is available for TBE; therefore the treatment is symptomatic. Patients with a potentially life threatening meningoencephalitis or meningoencephalomyelitis should be admitted to an intensive care unit. In the case of brain oedema, analgosedation should be deepened; osmotherapy and corticosteroids are not routinely recommended. If intracranial pressure is increased, therapeutic hypothermia or decompressive craniectomy might be considered. Seizures should be treated as any other symptomatic epileptic seizures. CONCLUSIONS: Tick-borne encephalitis is a viral CNS infection that may result in long-term neurological sequelae. Since its incidence in Europe is increasing due to broadening of endemic areas and prolongation of the tick activity season, the health burden of TBE is enlarging. There is no effective antiviral treatment for TBE, but the disease may be effectively prevented by vaccination.
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Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/prevenção & controle , Encefalite Transmitida por Carrapatos/terapia , Vacinação , Consenso , Diagnóstico Diferencial , Europa (Continente) , Humanos , Imunoglobulina M , MasculinoRESUMO
Mankind faces several global challenges such as chronic and acute hunger, global poverty, energy deficiency and environment conservation. Common biotechnologies based on batch, fluidbed and other similar processes are now extensively used for the production of a wide range of products such as antibiotics, biofuels, cultured and fermented food products. Unfortunately, these processes suffer from low efficiency, high energy demand, low controllability and rapid biocatalyst degradation by microbiological attack, and thus still are not capable of seriously addressing the global hunger and energy deficiency challenges. Moreover, sustainable future technologies require minimizing the environmental impact of toxic by-products by implementing the "life produces organic matter, organic matter sustains life" principle. Nanostructure-based biotechnology is one of the most promising approaches that can help to solve these challenges. In this work we briefly review the unique features of the carbon-based nanostructured platforms, with some attention paid to other nanomaterials. We discuss the main building blocks and processes to design and fabricate novel platforms, with a focus on dense arrays of the vertically-aligned nanostructures, mainly carbon nanotubes and graphene. Advantages and disadvantages of these systems are considered.
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Reatores Biológicos , Biotecnologia , Nanotubos de Carbono , NanoestruturasRESUMO
Graphene-based nanomaterials that combine significant photocatalytic, antioxidant and antibacterial activity are very attractive candidates for biomedical and environmental applications. Conventional chemical synthesis routes may contaminate the resultant materials with toxic molecules, compromising their properties and limiting their use in biomedical applications. Ideally, to avoid any contamination, the nanomaterials should be synthesized from non-toxic precursors and reagents, e.g. foodstuff via a simple technology that does not rely on the use of hazardous chemicals yet produces materials of high quality. Here, we report an environmentally friendly, low cost reduced graphene oxide-silver-silver oxide nanocomposite with strong photocatalytic, antioxidant and antibacterial activity for environmental remediation. The reduced graphene oxide (FRGO) is synthesized from edible sunflower oil via a simple flame synthesis method. Next, silver nanoparticles (Ag/AgO/Ag2O) are produced by phytochemical reduction of AgNO3 using a reducing agent based on flavonoids from Coleus aromaticus (Mexican mint), also used in food industry. Thus-obtained FRGO-Ag/AgO/Ag2O composite is characterized using X-ray diffraction spectroscopy, scanning electron microscopy, fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The degradation of anionic textile dye Methylene blue (MB) is used as a measure of photocatalytic activity of FRGO and FRGO/Ag/AgO/Ag2O, with solution pH, initial dye concentration, and quantity of the catalyst considered as influencing factors. FRGO-Ag/AgO/Ag2O composites show strong antioxidant activity, with improved radical inhibition as well as dye degradation properties when compared to pristine FRGO.
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Grafite , Nanopartículas Metálicas , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Óxidos , Prata/farmacologia , Compostos de PrataRESUMO
We have demonstrated the nonlinear absorption at 532 nm wavelength in an Au semi-continuous film (SF) resulting from smearing of the Fermi distribution and diffusion of conduction electrons into the substrate. The Au SF was irradiated by a pulsed laser with 8 ns pulse width at 532 nm in near resonance with the interband transition of the Au. We determined the temperature increase in the SF for different intensities by electrical measurement. We calculated the temperature increase by using a 1D heat transport equation; comparing the results of the calculation with measured values for the temperature increase, revealed the nonlinear absorption in the Au SF. We employed this deviation from linear behaviour to determine the nonlinear absorption coefficient.
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The formation of arrays of vertically aligned nanotips on a moderately heated (up to 500 degrees C) Si surface exposed to reactive low-temperature radio frequency (RF) Ar+H(2) plasmas is studied. It is demonstrated that the nanotip surface density, aspect ratio and height dispersion strongly depend on the substrate temperature, discharge power, and gas composition. It is shown that nanotips with aspect ratios from 2.0 to 4.0 can only be produced at a higher RF power density (41.7 mW cm(-3)) and a hydrogen content of about 60%, and that larger aspect ratios can be achieved at substrate temperatures of about 300 degrees C. The use of higher (up to 500 degrees C) temperatures leads to a decrease of the aspect ratio but promotes the formation of more uniform arrays with the height dispersion decreasing to 1.5. At lower (approximately 20 mW cm(-3)) RF power density, only semispherical nanodots can be produced. Based on these experimental results, a nanotip formation scenario is proposed suggesting that sputtering, etching, hydrogen termination, and atom/radical re-deposition are the main concurrent mechanisms for the nanostructure formation. Numerical calculations of the ion flux distribution and hydrogen termination profiles can be used to predict the nanotip shapes and are in a good agreement with the experimental results. This approach can be applied to describe the kinetics of low-temperature formation of other nanoscale materials by plasma treatment.
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Argônio/química , Cristalização/métodos , Hidrogênio/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Silício/química , Gases/química , Temperatura Alta , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
Events that stall bacterial protein synthesis activate the ssrA-tagging machinery, resulting in resumption of translation and addition of an 11-residue peptide to the carboxyl terminus of the nascent chain. This ssrA-encoded peptide tag marks the incomplete protein for degradation by the energy-dependent ClpXP protease. Here, a ribosome-associated protein, SspB, was found to bind specifically to ssrA-tagged proteins and to enhance recognition of these proteins by ClpXP. Cells with an sspB mutation are defective in degrading ssrA-tagged proteins, demonstrating that SspB is a specificity-enhancing factor for ClpXP that controls substrate choice.
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Adenosina Trifosfatases/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli , Escherichia coli/metabolismo , Oligopeptídeos/metabolismo , Serina Endopeptidases/metabolismo , Proteínas de Bactérias/genética , Endopeptidase Clp , Escherichia coli/enzimologia , Proteínas de Fluorescência Verde , Proteínas Luminescentes/metabolismo , Mutação , Oligopeptídeos/química , Oligopeptídeos/genética , Óperon , Ribossomos/metabolismo , Especificidade por SubstratoRESUMO
In austere environments, for example, in outer space, on surfaces of extra-terrestrial bodies (Moon, Mars, etc.), or under water, technologies that can enable continuous, reliable, and authentic monitoring of movement of human operators and devices can be critical. We report here the production and human body test of wearable, flexible graphene oxide stress sensors suitable for real-time monitoring of body parameters, state and position of humans, and automatic equipment. These sensors have excellent sensitivity and signal strength across a wide strain range, alleviating the need for additional instrumentation for signal processing and amplification. Their low cost makes them virtually disposable, which may benefit such applications as smart clothing. The sensors were fabricated by a concomitant reduction and N-doping of graphene oxide on polydimethylsiloxane in N2-H2 plasma. The direct bias and other plasma parameters have a significant effect on the reduction and properties of graphene oxide sensors, as shown by optical emission, Raman and X-ray photoelectron spectroscopies, and X-ray diffraction. Optical emission showed different excitation and ionization processes involving atomic and molecular species in the N2-H2 discharge. The photoelectron spectroscopy has confirmed the graphene reduction and introduction of nitrogen doping into the reduced graphene oxide. The bias efficiently controls plasma-induced electric fields, and plasma-related effects determine the N-doping levels. The reduced graphene oxides demonstrate excellent tensile properties, which make them suitable for efficient but cheap stress sensors. This eco-friendly, fast, room-temperature method shows a great potential for fabrication of efficient, flexible sensors.
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The paper presents results of comparative investigation of carbon nanotubes growth processes in dense low-temperature plasma and on substrate surface. Hybrid/Monte-Carlo numerical simulations were used to demonstrate the differences in the ion fluxes, growth rates and kinetics of adsorbed atoms re-distribution on substrate and nanotubes surfaces. We show that the plasma parameters significantly affect the nanotubes growth kinetics. We demonstrate that the growth rates of the nanotubes in plasma and on surface can differ by three orders, and the specific fluxes to the nanotube in the plasma can exceed the flux to surface-grown nanotube by six orders. We also show that the metal catalyst used for the nanotubes production on surface and in arc is a subject to very different conditions and this may be a key factor for the nanotube growth mode. The obtained dependencies for the ion fluxes to the nanotubes and nanotubes growth rates on the plasma parameters may be useful for selection of the production methods.
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Cristalização/métodos , Temperatura Alta , Modelos Químicos , Nanotecnologia/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Simulação por Computador , Campos Eletromagnéticos , Gases/química , Gases/efeitos da radiação , Substâncias Macromoleculares/química , Substâncias Macromoleculares/efeitos da radiação , Teste de Materiais , Conformação Molecular/efeitos da radiação , Nanotubos de Carbono/efeitos da radiação , Tamanho da Partícula , Propriedades de Superfície/efeitos da radiaçãoRESUMO
The original PDF version of this Article had an incorrect volume number of '8'; it should have been '9'. This has been corrected in the PDF version of the Article. The HTML version was correct from the time of publication.
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Drastic miniaturization of electronics and ingression of next-generation nanomaterials into space technology have provoked a renaissance in interplanetary flights and near-Earth space exploration using small unmanned satellites and systems. As the next stage, the NASA's 2015 Nanotechnology Roadmap initiative called for new design paradigms that integrate nanotechnology and conceptually new materials to build advanced, deep-space-capable, adaptive spacecraft. This review examines the cutting edge and discusses the opportunities for integration of nanomaterials into the most advanced types of electric propulsion devices that take advantage of their unique features and boost their efficiency and service life. Finally, we propose a concept of an adaptive thruster.
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Although extremely chemically reactive, oxygen plasmas feature certain properties that make them attractive not only for material removal via etching and sputtering, but also for driving and sustaining nucleation and growth of various nanostructures in plasma bulk and on plasma-exposed surfaces. In this minireview, a number of representative examples is used to demonstrate key mechanisms and unique capabilities of oxygen plasmas and how these can be used in present-day nano-fabrication. In addition to modification and functionalisation processes typical for oxygen plasmas, their ability to catalyse the growth of complex nanoarchitectures is emphasized. Two types of technologies based on oxygen plasmas, namely surface treatment without a change in the size and shape of surface features, as well as direct growth of oxide structures, are used to better illustrate the capabilities of oxygen plasmas as a powerful process environment. Future applications and possible challenges for the use of oxygen plasmas in nanofabrication are discussed.
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Replication of plasmid R6K is controlled by the homodimeric initiator protein pi, which binds to seven 22-bp direct repeats (iterons) in the gamma-origin. One of the genetically engineered pi variants (delta C164 pi) contains only the 164 N-terminal amino acids (aa) of the 305-aa pi molecule. This truncated pi polypeptide retains the ability to function as a specific inhibitor of R6K replication in vivo, though it neither drives replication, nor binds to iterons [Greener et al., Mol. Gen. Genet. 224 (1990) 24-32]. In order to define the region of pi responsible for dimerization, we have performed chemical crosslinking experiments with purified delta C164 pi and shown that this polypeptide is dimeric. We did not observe an exchange between protein monomers upon mixing of wild-type pi and delta C164 pi homodimers. However, heterodimers, as well as each type of homodimers, were formed when these polypeptides refolded after guanidine hydrochloride treatment. Thus, both dimerization and dimer stability are determined by the N-terminal domain of pi. We speculate that these properties might depend on the leucine zipper and RGD motifs that have been identified in the two regions of the N-terminal domain of pi.
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Proteínas de Bactérias/química , DNA Helicases , Replicação do DNA , Proteínas de Ligação a DNA , Fatores R , Transativadores , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Biopolímeros , Dados de Sequência Molecular , Dobramento de ProteínaRESUMO
The pi protein of plasmid R6K is involved in control of replication. The aim of this study was to use an in vitro replication system dependent on an R6K-derived gamma origin of replication (gamma ori) to compare replication characteristics of wt pi and a hyperactive variant of pi protein (piS87N; Filutowicz et al., 1994b. Cooperative binding of initiator protein to replication origin conferred by single amino acid substitution. Nucleic Acids Res. 22, 4211-4215). The characteristics of in vitro replication from gamma ori reported in this investigation are as follows: (i) piS87N is considerably more active in comparison to wt pi. (ii) Replication proceeds through Cairns-type intermediates and the initiation site and directionality of the fork movement are similar in the presence of both proteins. (iii) Replication forks emanate unidirectionally in the vicinity of the cluster of seven 22-bp direct repeats within gamma ori. (iv) Replication dependent on wt pi, but not piS87N, is stimulated up to 1.5-fold by rifampicin.
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DNA Helicases/metabolismo , Replicação do DNA , Proteínas de Ligação a DNA , Escherichia coli/genética , Plasmídeos/genética , Origem de Replicação , Transativadores/metabolismo , Sistema Livre de Células , DNA Helicases/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Variação Genética , Plasmídeos/ultraestrutura , Transativadores/genéticaRESUMO
Functional organization of mitochondrial genome (maxicircle kinetoplast DNA (kDNA)) from a flagellate protozoan Crithidia oncopelti was studied by Northern hybridization. A set of overlapping transcripts were mapped in the conserved region of the maxicircle. Several large (3-4 kb) RNAs, overlapping two or more smaller transcripts were found. Four regions produce a couple of RNAs differing in size 50-100 bases. Southern hybridization with several probes from the maxicircle kDNA of Leishmania tarentolae allowed identification of some of the found transcripts as corresponding to NADH dehydrogenase, subunit IV (Nd IV), cytochrome oxidase, subunits I-II (Cox I-II), cytochrome b (Cyt. b), ORF6-genes. Regions, homologous to the probes used are arranged in the same fashion in C. oncopelti kDNA as related genes in L. tarentolae. The divergent region was proved to be poorly transcribed and to produce a set of RNAs from 0.5 to 2.3 kb. Some transcripts of the divergent region seem to hybridize with distant maxicircular fragments. Cross-hybridization of such fragments has shown the absence of the regions of continuous homology.
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Crithidia/genética , DNA/genética , Transcrição Gênica , Animais , Sequência de Bases , Hibridização de Ácido Nucleico , RNA Ribossômico/genéticaRESUMO
An automated unit for manually controlled photometry and morphometry is described. It enables the operator to carry out photometrical measurements according to the plug-method and morphometrical measurements with the help of an object-micrometer or some kind of a grid. The data obtained are stored in the "Elektronika D3-28" microcomputer to be statistically evaluated after the end of sampling. New variables can be obtained defined by the user as a product of some source variables or their inverses. The data and control structures of the system are described in detail.
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Citofotometria/instrumentação , Citofotometria/métodos , Desenho de Equipamento , Microcomputadores , Microscopia/instrumentação , Software , U.R.S.S.RESUMO
A questionnaire was used to investigate 102 adolescents aged 14 to 18 suffering from infantile cerebral paralysis (spastic diplegia) with various degrees of motor disturbances. Neurasthenic, psychasthenic and sensitive types of character accentuation were most prevalent in these patients (p less than 0.05). Unstable type of character accentuation is also frequently occurring. The degree of motor disorders had a major impact on shaping and fixation of astheno-neurotic accentuation traits. Emotional experience of the cosmetic defect influenced fixation of the sensitive type traits. The new principles of organization of psychoprophylactic assistance and psychotherapeutic aid to these patients with respect to any "fragile links" in their characters are put forward.
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Paralisia Cerebral/psicologia , Caráter , Personalidade , Adolescente , Paralisia Cerebral/complicações , Humanos , Transtornos da Personalidade/etiologia , Transtornos da Personalidade/prevenção & controle , Transtornos da Personalidade/psicologia , Testes de Personalidade , Psicologia do AdolescenteRESUMO
The efficacy of influenca prophylaxis by a new Soviet chemopreparation tebrophen was studied during the influenza epidemics of 1972-1973 caused by the influenza virus of A/Hong-kong/68 and A/England/72/H3N2/types. Investigations were carried out under conditions of an epidemiological experience among the organized (adult) collective bodies (4352 persons in all). The preparation was instilled intranasally in the form of a 0.25 and 1% ointment on vaseline base. The efficacy index was 2.0-2.7, and the protection index--51--60%.