Mersenne Primes

Marin Mersenne’s mathematical contributions helped paved the way for advances in mathematics. In this article, his life is not only depicted but his mathematical intellect is highlighted through his achievements. Since his time, technology has helped further the finding of Mersenne primes. Prime numbers are large concepts for students to learn in school. Mersenne primes further examine the study of prime numbers

Пористая структура продуктов электрохимического синтеза на переменном токе нанодисперсных оксидов олова

Методами электронной микроскопии и низкотемпературной адсорбции азота изучена пористая структура продуктов электролиза металлического олова на переменном токе промышленной частоты. Установлено, что продукты синтеза характеризуются высокими значениями удельной площади поверхности и мезапористой структурой. Показано, что средний размер частиц варьирует в интервале 10…30 нм

Charging and discharging of graphene in ambient conditions studied with scanning probe microscopy

4 páginas, 3 figuras.-- Trabajo presentado como comunicación oral a la "European Conference on Surface Science ECOSS27" celbrado en Holanda en septiembre de 2010: http://www.ecoss27.eu/By means of scanning probe microscopy we are able to inject charges in isolated graphene sheets deposited on SiO2/Si wafers and characterize the discharge induced by water in controlled ambient conditions. Contact potential differences between the graphene surface and the probe tip, measured by Kelvin probe microscopy, show a linear relationship with the tip bias during charge injection. The discharge depends on relative humidity and decays exponentially with time constants of the order of tens of minutes. We propose that graphene discharges through the water film adsorbed on the SiO2 surface.This work was supported by the Ministerio de Educación y Ciencia (MEC), Spain, through Grant No. FIS2006-12117- C04-01, and by the EXPLORA program NAN2007-29375-E.Peer reviewe

Clinical Significance of Sentinel Lymph Node Detection in Patients with Invasive Cervical Cancer

The clinical significance of determining sentinel lymph nodes (SLN) in patients with invasive cervical cancer was studied. From 2013 to 2014, 30 cervical cancer patients (T1a1NxM0-T1b1NxM0) were treated at the Gynecological Oncology Department of the Cancer Research Institute. The day before surgery, four submucosal injections of 99mTc Al2O3 at a total dose of 80 MBq were made in each quadrant around the cervical tumor. Patients were submitted to preoperative lymphoscintigraphy and intraoperative SLN detection. The feasibility of preserving the reproductive potential in patients after radical abdominal trachelectomy was assessed. The 3-year, overall, disease-free and metastasis-free survival rates were analyzed. Thirty-four SLNs were detected by single-photon emission computed tomography (SPECT) and 42 SLNs were identified by intraoperative gamma probe. The sensitivity in detecting SLNs was 100% for intraoperative SLN identification and 80% for SPECT image. The reproductive potential was preserved in 86% of patients. The 3-year overall and metastases-free survival rates were 100%. Recurrence occurred in 8.6% of cases

Lean healthcare for reduction of the setup time in cardiac surgery: an analysis in a private hospital

Reducing processes setup time is one of the main purposes of Lean Manufacturing. This work has the goal to present an application of the combination of two Lean tools, the Ishikawa Diagram and the SMED methodology, to optimize the setup time between cardiac surgeries in the operating room of a private hospital. Initially, setup activities were mapped by drawing up a flowchart, and later a brainstorming session for the Ishikawa Diagram was done with the team to identify the possible causes of the delays. Following, the first two stages of the SMED (Single Minute Exchange of Die) methodology were applied, proposing the conversion of internal to external setup for the given activities. Although the hospital did not adopt the proposals while this study was built due to another project’s prioritization, a simulation of the new setup times showed that the total time reduction would be up to 20%. This corresponds to a capacity improvement of two cardiac surgeries per month, and in the absence of demand for this specialty, vacancies for other types of surgeries would also be opened, bringing gains in productivity and in the number of patients assisted

Membrane Cholesterol Strongly Influences Confined Diffusion of Prestin

Prestin is the membrane motor protein that drives outer hair cell (OHC) electromotility, a process that is essential for mammalian hearing. Prestin function is sensitive to membrane cholesterol levels, and numerous studies have suggested that prestin localizes in cholesterol-rich membrane microdomains. Previously, fluorescence recovery after photobleaching experiments were performed in HEK cells expressing prestin-GFP after cholesterol manipulations, and revealed evidence of transient confinement. To further characterize this apparent confined diffusion of prestin, we conjugated prestin to a photostable fluorophore (tetramethylrhodamine) and performed single-molecule fluorescence microscopy. Using single-particle tracking, we determined the microscopic diffusion coefficient from the full time course of the mean-squared deviation. Our results indicate that prestin undergoes diffusion in confinement regions, and that depletion of membrane cholesterol increases confinement size and decreases confinement strength. By interpreting the data in terms of a mathematical model of hop-diffusion, we quantified these cholesterol-induced changes in membrane organization. A complementary analysis of the distribution of squared displacements confirmed that cholesterol depletion reduces prestin confinement. These findings support the hypothesis that prestin function is intimately linked to membrane organization, and further promote a regulatory role for cholesterol in OHC and auditory function

Stopping the Itch: Sweat Treatment of Cholinergic Urticaria

Abstract Background: Chronic cholinergic urticaria is resistant to treatment, and patients can experience significant negative impacts on daily life. Generally, this condition can be diagnosed with a thorough history and physical examination. Then, treatment occurs stepwise, leading from common antihistamines, immunosuppressives, through monoclonal antibodies. In addition, there are several novel treatments on the horizon, including autologous sweat therapy. Purpose: This article aims to review the diagnosis and treatment of chronic cholinergic urticaria. Objective: The goal of this paper is to describe critical elements in the history, physical examination, and treatment of chronic cholinergic urticaria. Methods: This is a clinic review of cholinergic urticaria, including the pathogenesis, diagnosis, treatment, and current and future treatment modalities. Results: The causes of cholinergic urticaria are uncertain, but studies suggest an allergic reaction to histamine released in sweat or serum. Several randomized controlled clinical trials (RCTs) have demonstrated the benefit of immunosuppressives and monoclonal antibodies in treatment. In addition, a few studies suggest an autoimmune sweat allergy that could benefit from autologous sweat therapy, but future studies are required to confirm this modality as a treatment option. Conclusion: Chronic cholinergic urticaria can lead to debilitating symptoms impacting daily life. Emerging treatments show promise in providing patients relief from this condition. The goal of publishing this article is to bring greater awareness of this condition, current treatment options, and future opportunities to treat or cure this retractable condition. Keywords: Allergy, Autologous, Cholinergic, Chronic, Sweat, Urticari

Un cadre de configuration des variantes de processus à travers la fouille de processus et le raisonnement sémantique : une application dans le cadre de la santé.

The efficiency of organizations relies on its ability to adapt their business processes according to changes that may occur in the dynamic environment in which they operate. These adaptations result in new versions of the process model, known as process variants. Thus, several process variants can exist, which aim to represent all the related contexts that may differ in activities, resources, control flow, and data. Thus, has emerged the concept of customizable process model. It aims to adapt the process model according to changes in the business context. A process model can be customized by representing the process family in one single model enabling to derive a process variant through transformations in this single model. As benefits, this approach enables to avoid redundancies, promotes the model reuse and comparison, among others. However, the process variant customization is not a trivial-task. It must be ensured that the variant is correct in a structural and behavioural way (e.g. avoiding disconnected activities or deadlocks), and respecting all the requirements of the application context. Besides, the resulting process variant must respect all requirements related to the application context, internal and external regulations, among others. In addition, recommendations and guidance should be provided during the process customization. Guidance help the user to customize correct process variants, i.e., without behavioural problems. Recommendations about the process context help the user in customizing process variants according specific requirements. Recommendations about the business context refers to providing information about the best practices that can improve the quality of the process. In this context, this research aims to propose a framework for customizing process variants according to the user’s requirements. The customization is achieved by reasoning on ontologies based on the rules for selecting a process variant and in the internal/external regulations and expert knowledge. The framework is composed by three steps. The first step proposes to identify the process variants from an event log through process mining techniques, which enable to discover the variation points, i.e., the parts of the model that are subject to variation, the alternatives for the variation points and the rules to select the alternatives. By identifying the process variants and their characteristics from an event log, the process model can be correctly individualized by meeting the requirements of the context of application. Based on these aspects, the second step can be developed. This step refers to the development of the questionnaire-model approach. In the questionnaire approach each variation point is related to a question, and the alternatives for each question corresponds to the selection of the process variants. The third step corresponds to apply two ontologies for process model customization. One ontology formalizes the knowledge related with the internal and/or external regulations and expert knowledge. The other refers to the variation points, the alternatives for them and the rules for choosing each path. The ontologies then are merged into one new ontology, which contain the necessary knowledge for customize the process variants. Thus, by answering the questionnaire and by reasoning on the ontology, the alternatives related with the business process and the recommendations about the business context are provided for the user. The framework is evaluated through a case study related to the treatment of patients diagnosed with acute ischemic stroke. As result, the proposed framework provides a support decision-making during the process model customization.Les organisations doivent relever le défi d'adapter leurs processus aux changements qui peuvent survenir dans l'environnement dynamique dans lequel elles opèrent. Les adaptations dans le processus aboutissent à plusieurs variantes de processus, c'est-à-dire dans différentes versions du modèle de processus. Les variantes de processus peuvent différer en termes d'activités, de ressources, de flux de contrôle et de données. Ainsi, le concept d'un modèle de processus personnalisable est apparu et il vise à adapter le modèle de processus en fonction des exigences d'un contexte spécifique. Un modèle de processus personnalisable peut représenter toutes les variantes de processus dans un modèle unique dans lequel les parties communes ne sont représentées qu’une seule fois et les spécificités de chaque variante sont préservées. Alors, grâce à des transformations dans le modèle de processus générique, une variante de processus peut en être dérivée. En tant qu'avantages, cette approche permet d'éliminer les redondances, favorise la réutilisation, entre autres. Cependant, la personnalisation des modèles de processus n'est pas une tâche triviale. La personnalisation doit assurer que la variante obtenue est correcte du point de vue structurel et comportemental, c'est-à-dire la variante obtenue ne doit pas présenter d'activités déconnectées, d’interblocages actifs ou d'interblocages, entre autres. En outre, la variante de processus doit satisfaire à toutes les exigences du contexte de l'application, aux réglementations internes et externes, entre autres. De plus, il est nécessaire de fournir à l'utilisateur des directives et des recommandations lors de la personnalisation du processus. Les directives permettent la personnalisation correcte des variantes de processus, en évitant les problèmes de comportement. Les recommandations concernant le contexte de l'entreprise rendent possible l'amélioration du processus et aussi la personnalisation des variantes en fonction des besoins spécifiques. Dans ce contexte, cette recherche propose un cadre pour la personnalisation des variantes de processus en fonction des besoins de l'utilisateur. La personnalisation est réalisée grâce à l'utilisation d'ontologies pour la sélection des variantes. Le cadre est composé de trois étapes. La première correspond à l'identification des variantes à partir d'un journal d'événements au moyen de techniques d'exploration de processus, qui permettent de découvrir des points de variation, c'est-à-dire les parties du processus sujettes à variation, les alternatives disponibles pour chaque point de variation et les règles de sélection des alternatives disponibles. L'identification des variantes de processus et de leurs caractéristiques à partir d'un journal des événements permet de personnaliser un modèle de processus en fonction du contexte de l'application. À partir de ces aspects, la deuxième étape peut être développée. Cette étape concerne le développement d'un questionnaire, dans lequel chaque question est liée à un point de variation et chaque réponse correspond à la sélection d'une variante. Dans la troisième étape, deux ontologies sont proposées. La première formalise les connaissances liées aux réglementations externes et internes et aux connaissances des spécialistes. La deuxième ontologie se réfère aux points de variation, aux alternatives existantes pour chaque point de variation et aux règles liées à la sélection de chaque alternative. Ensuite, ces ontologies sont intégrées dans une nouvelle ontologie, qui contient les connaissances nécessaires pour personnaliser la variante de processus. Ainsi, à travers le questionnaire et le raisonnement sémantique, la variante est sélectionnée et les recommandations concernant le processus d’affaires sont fournies en fonction de la sélection de l'utilisateur lors de la personnalisation du processus. Le cadre proposé est évalué au moyen d'une étude de cas liée au traitement des patients chez qui un AVC ischémique aigu a été diagnostiqué. Les recommandations obtenues grâce à l'approche développée fournissent un support pour la prise de décision lors de la personnalisation du modèle de processus.Organizações enfrentam o desafio de adaptar seus processos de acordo com mudanças que podem ocorrer no ambiente dinâmico em que operam. Adaptações no processo resultam em diversas variantes de processo, isto é, em diferentes versões do modelo de processo. As variantes de processo podem diferir em atividades, recursos, fluxo de controle e dados. Assim, surgiu o conceito de modelo de processo customizável, que tem como objetivo adaptar o modelo de processo de acordo com os requisitos de um contexto especifico. Um modelo de processo customizável pode representar todas as variantes de processos em um único modelo, no qual as partes comuns são representadas apenas uma vez e as especificidades de cada variante é preservada. Assim, por meio de transformações no modelo de processo genérico uma variante de processo pode ser derivada. Como benefícios, esta abordagem possibilita eliminar redundâncias, promove o reuso, entre outros. No entanto, a customização de modelos de processo não é uma tarefa trivial. A customização deve garantir que a variante obtida seja correta tanto do ponto de vista estrutural quanto comportamental, ou seja, a variante obtida não deve apresentar atividades desconectadas, livelocks ou deadlocks, entre outros. Além disso, a variante de processo deve respeitar todos os requisitos do contexto de aplicação, regulações internas e externas, entre outros. Em adição, é necessário fornecer ao usuário orientações e recomendações durante a customização do processo. Orientações permitem a correta customização de variantes de processo, evitando problemas comportamentais. Recomendações a respeito do contexto do negócio possibilitam a melhoria do processo e também a customização de variantes de acordo com requisitos específicos. Neste contexto, esta pesquisa propõe um framework para a customização de variantes de processo de acordo com os requisitos do usuário. A customização é realizada através do uso de ontologias para a seleção de variantes. O framework é composto de três passos. O primeiro corresponde a identificação das variantes a partir de um registro de eventos por meio de técnicas de mineração de processos, as quais possibilitam a descoberta dos pontos de variação, isto é, as partes do processo que estão sujeitos à variação, as alternativas disponíveis para cada ponto de variação e as regras para a seleção das alternativas disponíveis. A identificação das variantes de processo e suas características com base em um log de eventos, permite customizar um modelo de processo de acordo com o contexto de aplicação. Baseado nestes aspectos, o segundo passo pode ser desenvolvido. Este passo refere-se ao desenvolvimento de um questionário, no qual cada pergunta esta relacionada a um ponto de variação e cada resposta corresponde a seleção de uma variante. No terceiro passo, duas ontologias são propostas. A primeira formaliza o conhecimento relacionado às regulações externas e internas e o conhecimento de especialistas. A segunda ontologia referese aos pontos de variação, às alternativas existentes para cada ponto de variação e às regras relacionadas a seleção de cada alternativa. Em seguida, estas ontologias são integradas em uma nova ontologia, a qual contém o conhecimento necessário para customizar a variante de processo. Desta forma, por meio do questionário e do raciocínio semântico, a variante é selecionada e as recomendações a respeito do processo de negócio são fornecidas de acordo com a seleção do usuário durante a customização do processo. O framework proposto é avaliado através de um estudo de caso relacionado ao tratamento de pacientes diagnosticados com acidente vascular cerebral isquêmico agudo. As recomendações obtidas por meio da abordagem desenvolvida fornecem um suporte a tomada de decisão durante a customização do modelo de processo