Improved Composite Q-Function Approximation and its Application in ASEP of Digital Modulations over Fading Channels

In this paper, capitalizing on Mils ratio for Qfunction approximation, we have presented novel improved composite Q-function approximation. Based on our improved approximation, we have further presented tight approximation for the average symbol error probability (ASEP) expressions of digital modulations over Nakagami-m fading channels. First, comparison to other known Q-function closed-form approximations has been performed, and it has been shown that accuracy improvement has been achieved in the observed range of values. Further, it has been shown that by using proposed approximation, values of average symbol error probability (ASEP) for some applied modulation formats could be efficiently and accurately evaluated when transmission over Nakagami-m fading channels is observed. Also, it has been shown in the paper that by using proposed approximation, observed ASEP measures are bounded more closely, than by using other known Q-function closed-form approximations

Various aspects of two treatment approaches to patients with problems of hypodontia of upper lateral incisors

Introduction. The treatment of hypodontia of the upper lateral incisors could be orthodontic or multidisciplinary with combined orthodontic, surgical and prosthetic in-volvement. Both options have their pros and cons. They could be quite challenging to manage, particularly in the cases of unilateral missing of the upper lateral incisor in adult patients. We presented two cases with these different treatment approaches in young adult patients with unilateral missing of upper lateral incisors. Case report. The first case presents a combined orthodontic, surgical and prosthetic treatment of the missing upper right lateral incisor in an adult patient. Our clinical examination of a 22-year-old girl showed her missing tooth 12 with almost completely closed space, midline deviation, reduced overjet and overbite, Class III molar relationship on the right side and Class I molar relationship on the left side with V-shape maxillary arch and crossbite tendency in the frontal region. Based on the skeletal Class III relationship and intraoral findings, it was decided to open the space for tooth 12 and to establish the over jet, overbite and Class I occlusion as well. A surgical implant insertion followed the orthodontic preparation, with crown positioning after surgical healing. The second case described the orthodontic treatment of unilateral hypodontia in a young adult patient. Clinical and radiographic examinations of a 24-year-old female revealed hypodontia of tooth 12 with microdontic conical tooth 22 with severe crowding in the lower arch, Class I molar relationship on the right side and half-Class II relationship on the left side. The treatment decision was to extract atypical tooth 22, teeth 35 and 44 and to move the upper teeth forward to close the space. Af- ter the orthodontic treatment, upper canines were mesially moved to replace those missing lateral incisors. Conclu- sion. Both treatments successfully resolved malocclusion and obtained solid aesthetic and functional results. The treatment plan and decision to open or close the space in a case of hypodontia should be made individually for each pa- tient according to their age, malocclusion, canines' shape and size and patient preferences

Heat generation during plunge stage in friction stir welding

This paper deals with the heat generation in the Al alloy Al2024-T3 plate under different rotating speeds and plunge speeds during the plunge stage of friction stir welding. A 3-D finite element model is developed in the commercial code ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson- Cook material law, and Coulomb's Law of friction. The heat generation in friction stir welding can be divided into two parts: frictional heat generated by the tool and heat generated by material deformation near the pin and the tool shoulder region. Numerical results obtained in this work indicate a more prominent influence from the friction-generated heat. The slip rate of the tool relative to the workpiece material is related to this portion of heat. The material velocity, on the other hand, is related to the heat generated by plastic deformation. Increasing the plunging speed of the tool decreases the friction-generated heat and increases the amount of deformation-generated heat, while increasing the tool rotating speed has the opposite influence on both heat portions. Numerical results are compared with the experimental ones, in order to validate the numerical model, and a good agreement is obtained

Removal of rose bengal dye by hydrophobic carbon quantum dots and polyurethane nanocomposites

In the present study we report the removal of Rose Bengal dye by gamma irradiated nanocomposites composed of hydrophobic carbon quantum dots incorporated in the matrix of polyurethane (hCQD-PU). It is assumed that the removal is caused by the combination of two different mechanisms. First mechanism suggested is a photocatalytic degradation by lightinduced production of singlet oxygen and other reactive oxygen species by gamma irradiated hCQD and second mechanism is the adsorption of the remaining Rose Bengal dye from the solution, by polymer matrix. The removal efficiency of the dye reached up to 92% for 4 h of irradiation by visible lamp. We have investigated the effect of different parameters, such as the dose of gamma irradiation applied to the nanocomposite, as well as the exposure time of the sample to the blue lamp (470 nm). The proposed material has a potential in water purification systems

Antibacterial potential of electrochemically exfoliated graphene sheets

Electrochemically exfoliated graphene is functionalized graphene with potential application in biomedicine. Two most relevant biological features of this material are its electrical conductivity and excellent water dispersibility. In this study we have tried to establish the correlation between graphene structure and its antibacterial properties. The exfoliation process was performed in a two electrode-highly oriented pyrolytic graphite electrochemical cell. Solution of ammonium persulfate was used as an electrolyte. Exfoliated graphene sheets were dispersed in aqueous media and characterized by atomic force microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X photoelectron spectroscopy, X-ray diffraction, electron paramagnetic resonance, zeta potential, contact angle measurements and surface energy. Antibacterial assays have shown lack of the significant antibacterial activity. Major effect on bacteria was slight change of bacteria morphology. Membrane remained intact despite significant change of chemical content of membrane components.This is the peer reviewed version of the paper: Marković, Z. M., Matijašević, D. M., Pavlović, V. B., Jovanović, S. P., Holclajtner-Antunović, I. D., Špitalský, Z., Mičušik, M., Dramićanin, M. D., Milivojević, D. D., Nikšić, M. P., & Todorović Marković, B. M. (2017). Antibacterial potential of electrochemically exfoliated graphene sheets. Journal of Colloid and Interface Science, 500, 30–43. [https://doi.org/10.1016/j.jcis.2017.03.110][https://www.sciencedirect.com/science/article/abs/pii/S0021979717303776?via%3Dihub

Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort

BACKGROUND: Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. METHODS: A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. RESULTS: SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced 651 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with 651 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not 655. CONCLUSIONS: In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin

Avaliação da viscosidade e massa molar de quitosanas modificadas enzimaticamente

Orientador: Telma Teixeira FrancoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: A biocompatibilidade, biodegradabilidade e o fato de ser um polimero catiônico bioadesivo fazem a quitosana um material atrativo para inúmeras aplicações na área biotecnológica, agrícola, farmacêutica e médica. As quito sanas com massas molares baixas e os oligômeros têm maiores perspectivas nas últimas duas áreas. O objetivo deste projeto de pesquisa foi a obtenção de polimeros com massa molar média reduzida devido à ação da enzima papaína. Empregando papaína livre e em forma imobilizada a redução da massa molar da quito sana foi estudada. Quitina foi utilizada como suporte para imobilização da papaína e para imobilização da proteína modelo albumina de soro bovino. Experimentos com todos estes materiais foram realizados para estudar os efeitos da modificação da quito sana. Os experimentos foram conduzidos em reatores batelada com pH e temperatura controlados. Soluções da quito sana (1 %) foram preparadas utilizando ácido lático ou ácido acético para solubilização. Duas técnicas para determinação da massa molar da quito sana foram utilizadas. Em primeiro lugar, a visco simetria foi empregada sendo esta a técnica mais comum para investigação de redução da massa molar. Redução da viscosidade de soluções de quitosana foi associada à diminuição da massa molar média. Outro método utilizado para a determinação de massas molares foi a cromatografia de permeação em gel, que é considerado um método relativo de determinação de massa molar, pois necessita de padrões dos polimeros para a construção de uma curva padrão. A massa molar determinada por estes dois métodos é dependente do tamanho da molécula (diâmetro). O método absoluto de determinação da massa molar com detector de espalhamento de luz também foi utilizado. Este detector conectado on-line com cromatografia de permeação em gel fornece dados absolutos da massa molar média. Luz espalhada de diferentes partes da molécula do polimero em diferentes ângulos geram o valor correto da massa molar sem utilização dos padrões. Os resultados mostraram o efeito superior na redução da massa molar utilizando papaína em comparação com outros materiais utilizados. Esta redução da massa molar média é rápida e acentuada nos primeiros minutos da reação, em comparação com a continuação do processoAbstract: Biocompatibility, biodegradability and the fact of being bioadhesive polycationic polymer make chitosan an attractive material for various applications in agricultural and biotechnological, pharmaceutical and medical fields. Chitosans with lower molecular weights and oligomers OOve major perspectives in the last two fields. An objective of this project of research was the production of polymers with reduced molecular weight due to the action of enzyme papain. Applying papain in the free and immobilized form the reduction of molecular weight of chitosan was studied. Chitin was used as a support for the immobilization of papain and for the immobilization of model protein bovine serum albumin. Experiments with all these materiais were realized to study the effects of modification of chitosan. Experiments were run using batch reactors at controled pH and temperature. Chitosan solutions (1 %) were prepared using lactic acid or acetic acid for solubilization. Two different techniques were used for determination of molecular weight of chitosan. First viscosimetry was applied as the most common technique used for investigation of reduction of molecular weights. Reduction of viscosity of chitosan solutions is associated with the reduction of molecular weight. The other method used for determination of molecular weights is gel permeation chromatography toot is considered a relative method of determination of molecular weights as it requires polymeric standards for the construction of the standard curve. Molecular weight determined by these two methods is dependant of the molecular size (diameter). Absolute method of determination of molecular weights through measurements with detector of light scattering was aIso applied in this studies. This detector connected on-line with gel penneation chromatography provides us with the absolute molecular weights. This method does not require standards measuring the light scattered from different parts of the polymeric molecule in different angles generating in this way the correct value of molecular weight. Results show the superior effect of papain on the reduction of molecular weight compared to the other materiais used. This reduction of molecular weight is fast, pronounced in the :fust minutes of the reaction in comparison with the continuation of the processMestradoDesenvolvimento de Processos QuímicosMestre em Engenharia Químic

Neutrino Oscillations Founded on Tachyon Theory of Neutrino

Abstract: De Broglie&apos;s neutrino relations have been derived in this paper in the spirit of tachyon neutrino theory. The analysis of the physical characteristics of the neutrino as the tachyon particle has been done and a formula derived for the oscillation length. By analyzing phase angle of the plane wave, we came to the conclusion that the oscillations of neutrinos could be performed by speeds greater than the speed of light. Starting off from the application of Heisenberg&apos;s uncertainty relation in the micro-world, the postulate of neutrino confinement was introduced in the macroscopic area defined by the neutrino oscillation length. It is shown that the neutrino mass which belongs to the tachyon four-dimension space-time and the neutrino mass of the four-dimension space-time of the theory of relativity are not mutually equal by value, but the corresponding energy and momentum are unchanging