Electrically tunable two-dimensional liquid crystals gratings induced by polarization holography

Two-dimensional (2D) gratings made up of an array of differently twisted nematic structures are obtained by crossed assembling of 1D polarization holograms recorded at the photoaligning substrates. The rotating linear polarization pattern, produced by the interference of two opposite circularly polarized beams, is recorded on the azo-dye doped polyimide aligning layers. The 2D gratings diffract light in different directions with different polarization states, that can be optically controlled. Orthogonal circularly and linearly polarized diffraction orders are simultaneously obtained irradiating the grating with a linearly polarized beam. An external ac voltage allows to completely control the diffracted energy distribution. (c) 2007 Optical Society of Americ

Surface-induced photorefractivity in twistable nematics: toward the all-optical control of gain.

We report the first two-beam coupling investigation of the surface-induced photorefractive effect (SIPRE) in optically twistable nematic liquid crystal cell. The unique space-charge field of SIPRE is exploited to achieve optical tuning of the photorefractive gain. A reconfigurable photoaligning substrate is used to adjust the twist angle, which is proved to be a control parameter for the photorefractive gain. The amplitude of the optical modulation increases gradually with the twist. Its phase shift changes from 0 degrees to 90 degrees with the polarization state of the two interfering beams. These results pave the way to the all-optical control of the photorefractive gain

Relevance of dental care in hospitals: a brief systematic review

Introduction: In the scenario of dental care in hospitals, attention should not be focused only on dental treatment, but first assess the patient's health status. Dentistry is of paramount importance in preventive actions, as well as in the elimination of inflammatory, infectious and painful symptomatological processes that may contribute to the loss of hospitalized patients. Objective: The present study described the importance of the dentist's role in the hospital environment, as well as the dental care in the hospital environment as a decision tool for other treatments or surgical procedures. Methods: The present study followed a systematic review model, following the rules of systematic review – PRISMA. The search strategy was performed in the PubMed, Cochrane Library, Web of Science and Scopus, and Google Scholar databases. The present study was carried out from February to May of 2022. Results and Conclusion: A total of 107 articles were found. A total of 57 articles were fully evaluated and 18 were included and discussed in this study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 20 studies that were excluded with a high risk of bias (studies with a small sample size). Also, 20 studies were excluded because they did not meet the GRADE, and 39 studies were excluded for presenting a minor risk of bias. The dentist must promote the general health of the hospitalized individual, based on interdisciplinary planning developed together with other health professionals, as well as assess the main needs of the patient and contribute to the quality of life of these individuals. The role of the dentist as an integral part of the multi-professional team in the area of health in the ICU is fundamental, as its presence could minimize problems in hospitalized patients

Introdução de mecanismo de segurança em sistemas de correio eletronico ;

Orientador: Claudio Leonardo LucchesiDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Este trabalho tem por objetivo apresentar e avaliar um sistema criado para prover segurança ao ambiente de correio eletrônico do editor Emacs: o programa ProtegeMail. Construído na linguagem Emacs LISP, o ProtegeMail consiste em uma extensão dos subsistemas de correio eletrônico do Emacs (VM, RMAIL, MH-E e GNUS). Ele funciona como uma interface modular para chamar funções criptográficas existentes nos programas de segurança de e-mail PGP e RIPEM. Inicialmente, este trabalho apresenta e discute a funcionalidade, a ,segurança e os protocolos, padrões e programas relacionados com o conceito de correio eletrônico. Em seguida, apresenta os aspectos específicos da utilização de criptografia em correio eletrônico. Depois, descreve e compara os pacotes PGP e PEM. Também apresenta e analisa a escolha do Emacs como ambiente alvo. Por fim, descreve e avalia o sistema ProtegeMail, através de suas principais funções e da segurança que proporciona ao usuárioAbstract: The major goal of this work is to present and to evaluate a system created to provide security for the Emacs editor electronic mail environment: the ProtegeMail program. Developed with Emacs Lisp language, ProtegeMail consists of an Emacs e-mail subsystems (VM, RMAIL, MH-E and GNUS) extension. It operates like a modular interface, calling cryptographic functions existing in PGP and RIPEM e-mail security programs. First, this work presents and discusses the functionality, security, and the protocols, standards and programs related with electronic mail concept. It then presents specific aspects of criptography applied to electronic mail. After this, it describes and compares PGP and PEM packets. It also presents and analyzes the choice of Emacs as a target environment. Finally, it describes and evaluates the ProtegeMail system, through its main functions and the security that it provides to the userMestradoMestre em Ciência da Computaçã

Estudo sobre o artigo 514 do Código de Processo Penal

Discute os aspectos doutrinários e jurisprudenciais concernentes ao Código de Processo Penal, mormente na questão sobre ser ou não ser a falta de atendimento à formalidade, prevista no artigo 514, nulidade absoluta ou relativa. Analisa as hipóteses, referentes a nulidade relativa, em que sua aplicação e exigível e quais os requisitos necessário para sua aplicação, para assim responder, caso a caso, quando é ou não necessária, a notificação para apresentação da defesa preliminar, antes do recebimento da denúncia

HPV Technologies Advancing Public Health: Discussion of Recent Evidence

Effective primary and secondary cancer prevention programmes are key to improve public health. Cervical cancer is preventable if high quality screening programmes, diagnosis and treatment are offered to female populations at high coverage. Nevertheless, it continues to be a public health problem, and screening programmes need improvements. Human papillomavirus (HPV) has been firmely established as the necessary cause of virtually all cervical cancer cases. To date we count two clinically validated and approved HPV technologies, available to prevent cervical cancer, and other diseases caused by these carcinogenic viruses: Prophylactic vaccines for primary prevention, and HPV DNA tests for secondary prevention, to detect life threatening infections by carcinogenic HPV types, allowing timely diagnosis and clinical management of precancerous lesions. The new technologies will help improve the health of the public if made widely accessible. Similar to vaccination programmes, systematic and well organized cervical screening programmes, with high quality validated HPV tests, can save more lives than ever and improve women’s health, in an effective manner

Polarization gradient: exploring an original route for optical trapping and manipulation.

We report a study of the capabilities of an optical tweezer based on polarization gradient. We use a light polarization pattern that is able to simultaneously exert forces and torques in opposite directions depending on the particle's position. It allows to perform oscillatory displacements and control the sense of rotation of several particles inside a uniformly illuminated region. Unconventional trapping of spinning particles in circularly polarized fringes has been observed, which suggests the involvement of hydrodynamic forces

Internet Authentication for Remote Access

It is expected that future IP devices will employ a variety of different network access technologies to gain ubiquitous connectivity. Currently there are no authentication protocols available that are lightweight, can be carried over arbitrary access networks, and are flexible enough to be re-used in the many different contexts that are likely to arise in future Internet remote access. Furthermore, existing access procedures need to be enhanced to offer protection against Denial-of-Service (DoS) attacks, and do not provide non-repudiation. In addition to being limited to specific access media, some of these protocols are limited to specific network topologies and are not scalable. This thesis reviews the authentication infrastructure challenges for future Internet remote access supporting ubiquitous client mobility, and proposes a series of solutions obtained by adapting and reinforcing security techniques arising from a variety of different sources. The focus is on entity authentication protocols that can be carried both by the IETF PANA authentication carrier and by the EAP mechanisms, and possibly making use of an AAA infrastructure. The core idea is to adapt authentication protocols arising from the mobile telecommunications sphere to Internet remote access. A proposal is also given for Internet access using a public key based authentication protocol. The subsequent security analysis of the proposed authentication protocols covers a variety of aspects, including: key freshness, DoS-resistance, and "false-entity-in-the-middle" attacks, in addition to identity privacy of users accessing the Internet via mobile devices. This work aims primarily at contributing to ongoing research on the authentication infrastructure for the Internet remote access environment, and at reviewing and adapting authentication solutions implemented in other spheres, for instance in mobile telecommunications systems, for use in Internet remote access networks supporting ubiquitous mobilit