Efficiency of linked cell algorithms

The linked cell list algorithm is an essential part of molecular simulation software, both molecular dynamics and Monte Carlo. Though it scales linearly with the number of particles, there has been a constant interest in increasing its efficiency, because a large part of CPU time is spent to identify the interacting particles. Several recent publications proposed improvements to the algorithm and investigated their efficiency by applying them to particular setups. In this publication we develop a general method to evaluate the efficiency of these algorithms, which is mostly independent of the parameters of the simulation, and test it for a number of linked cell list algorithms. We also propose a combination of linked cell reordering and interaction sorting that shows a good efficiency for a broad range of simulation setups.Comment: Submitted to Computer Physics Communications on 22 December 2009, still awaiting a referee repor

EXPERIMENTAL AND COMPUTATIONAL INVESTIGATION OF PLANAR ION DRAG MICROPUMP GEOMETRICAL DESIGN PARAMETERS

To deal with increasing heat fluxes in electronic devices and sensors, innovative new thermal management systems are needed. Proper cooling is essential to increasing reliability, operating speeds, and signal-to-noise ratio. This can be achieved only with precise spatial and temporal temperature control. In addition, miniaturization of electric circuits in sensors and detectors limits the size of the associated cooling systems, thereby posing an added challenge. An innovative answer to the problem is to employ an electrohydrodynamic (EHD) pumping mechanism to remove heat from precise locations in a strictly controlled fashion. This can potentially be achieved by micro-cooling loops with micro-EHD pumps. Such pumps are easily manufactured using conventional microfabrication batch technologies. The present work investigates ion drag pumping for applications in reliable and cost effective EHD micropumps for spot cooling. The study examines the development, fabrication, and operation of micropumps under static and dynamic conditions. An optimization study is performed using the experimental data from the micropump prototype tests, and a numerical model is built using finite element methods. Many factors were involved in the optimization of the micropump design. A thorough analysis was performed of the major performance-controlling variables: electrode and inter-electrode pair spacing, electrode thickness and shape, and flow channel height. Electrode spacing was varied from 10 µm to 200 µm and channel heights from 50 µm to 500 µm. Also, degradation of the electrodes under the influence of an intense electric field was addressed. This design factor, though important in the reliability of EHD micropumps, has received little attention in the scientific and industrial applications literature. Experimental tests were conducted with prototype micropumps using the electronic liquid HFE7100 (3M®). Flow rates of up to 15 ml/min under 15 mW power consumption and static pumping heads up to 750 Pa were achieved. Such performance values are acceptable for some electronic cooling applications, where small but precise temperature gradients are required

CHEMICAL AND MINERALOGICAL ANALYSIS OF HIGH-PURITY QUARTZ FROM NEW DEPOSITS IN A GREEK ISLAND, FOR POTENTIAL EXPLORATION

The current study presents an original chemical, elemental and mineralogical characterization of new quartz mineral deposits situated in Ios island, Cyclades, Aegean sea, Greece, via X-Ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) trace-element analysis. Actually, the mineral Quartz (crystalline SiO2) is found in nature in varying quality and is explored and traded for use in different applications of significant importance depending on the quartz purity. The results of the thorough chemical and mineralogical analysis indicate that quartz originating from the location examined in this research is almost free from other microcrystalline phases, and therefore it can be characterized as highly pure α-quartz. Thus, it can be used in the industry of ultra-high purity quartz production for specific applications, as long as the deposits are exploitable. In this framework, a preliminary estimation of the economic benefits from a potential exploration versus the environmental aspects of mining, taking into account sustainability issues in the region, is provided highlighting the local social need

Vienmomenčių kaklo ir širdies kraujagyslių operacijų ankstyvieji ir vėlyvieji rezultatai

Donatas Inčiūra1, Rimantas Benetis1,2, Šarūnas Kinduris1,3 1 Kauno medicinos universiteto klinikų Širdies, krūtinės ir kraujagyslių chirurgijos klinika, Eivenių g. 2, LT-50009 Kaunas 2 Kardiologijos institutas, Sukilėlių g. 17, LT-50009 Kaunas 3 Kauno medicinos universiteto Biomedicininių tyrimų institutas, Eivenių g. 4, LT-50009 Kaunas El paštas: [email protected] Įvadas / tikslas Nustatyti vienmomenčių vainikinių jungčių suformavimo ir miego arterijų endarterektomijų operacijų įtaką bendriems pooperaciniams rezultatams, ligonių išgyvenamumui ir vėlyvam insultui lyginant su izoliuotomis miokardo revaskulizacijos operacijomis. Ligoniai ir metodai KMUK Širdies, krūtinės ir kraujagyslių klinikoje per pastaruosius penkerius metus atliktos 49 vienmomentės miokardo revaskulizacijos ir miego arterijų endarterektomijų operacijos. Rezultatai Palyginti su izoliuotų miokardo revaskulizacijos operacijų grupe, kompleksinės miego arterijų pažeidimo grupės ligoniai buvo vyresni (atitinkamai 69,9 m. (6,54) ir 65,46 m. (9,60), p < 0,01), daugiau jų sirgo cukriniu diabetu (16 (32,7%) ir 14 (16,7%), p < 0,05) ir periferinių kraujagyslių ateroskleroze (16 (32,7%) ir 8 (9,5%), p < 0,01). Vienmomenčių operacijų trukmė (254,39 (76,21) min. ir 217,50 min. (65,66), p < 0,01) ir kompleksiškai operuotų ligonių hospitalizacijos laikas (34,98 paros (14,78) ir 26,79 paros (15,37), p < 0,01) buvo ilgesni. Nors kompleksiškai operuotiems ligoniams nustatyti reikšmingi operacinės rizikos veiksniai, kompleksinės miego arterijų pažeidimo grupės ligonių pooperacinių komplikacijų dažnis ir mirštamumas reikšmingai nesiskyrė nuo kontrolinės miokardo revaskulizacijos operacijų grupės. Vienmomentiškai operuotų ligonių išgyvenamumo ir vėlyvo insulto tikimybė nesiskiria nuo izoliuotų miokardo revaskulizacijos operacijų stebėjimo laikotarpiu iki 62 mėnesių. Išvados Kompleksinės išeminės širdies ligos ir kaklo kraujagyslių vienmomentės operacijos rezultatai nesiskiria nuo izoliuotos miokardo revaskulizacijos operacijų rezultatų, todėl atlikti jas vienmomentiškai yra saugu. Pagrindiniai žodžiai: išeminė širdies liga, miego arterijų pažeidimas, kompleksinės operacijos Early and late clinical outcomes of simultaneous coronary and carotid artery operations Donatas Inčiūra1, Rimantas Benetis1,2, Šarūnas Kinduris1,3 1 Kaunas University of Medicine Hospital, Department of Cardiothoracic and Vascular Surgery, Eivenių str. 2, LT-50009 Kaunas, Lithuania 2 Institute of Cardiology, Sukilėlių str. 17, LT-50009 Kaunas, Lithuania 3 Institute for Biomedical Research, Eivenių str. 4, LT-50009 Kaunas, Lithuania E-mail: [email protected] Background / objective The optimal management of patients with significant carotid and coronary artery disease remains controversial. The aim of the study was to compare the early and late clinical outcomes of simultaneous coronary and carotid artery operations versus isolated coronary artery bypass grafting operations. Patients and methods From 2000 through 2005, 45 patients underwent simultaneous carotid endarterectomy following coronary artery bypass grafting. Results Patients that underwent simultaneous operations were older (69.9 y. (6.54) vs. 65.46 y. (9.60), p < 0.01), had more diabetes mellitus (16 (32.7%) vs. 14 (16.7%.), p < 0.05) and peripheral artery disease (16 (32.7%) vs. 8 (9.5%), p < 0.01). Duration of combined operations (254.39 (76.21) min vs. 217.50 min (65.66), p < 0.01) and hospitalization (34.98 days (14.78) vs. 26.79 days (15.37), p < 0.01) was longer in the simultaneous group. The frequency of postoperative complications and mortality in the carotid artery group did not reliably differ as compared with the control group. In the combined carotid artery group, the survival and late stroke probability did not differ as compared with the control isolated coronary artery bypass grafting group in the follow-up period (62 months). Conclusions Simultaneous carotid endarterectomy and coronary artery bypass grafting operations resulted in a low perioperative mortality and morbidity rates in high-risk patients and are safe to be performed on patients with concomitant carotid artery disease. Key words: ischemic heart disease, carotid artery stenosis, simultaneous operatio

Association between obesity and high blood pressure among Lithuanian adolescents: a cross-sectional study

BACKGROUND: Most epidemiological studies have shown that the prevalence of high blood pressure (BP) has significantly increased among children and adolescents in various countries of the world. The aim of this study was to examine the associations between overweight, obesity, abdominal obesity and prehypertension and hypertension among Lithuanian adolescents aged 12–15 years. METHODS: The subjects with increased BP (≥90th percentile) were screened on two separate occasions. Data on the body mass index (BMI), waist circumference (WC), and BP were analysed in 7,457 adolescents aged 12–15 years. Adjusted odds ratios (aORs) with 95% confidence intervals (CI) for the associations were estimated using multivariate logistic regression models. RESULTS: After two screenings, the study participants were categorised as prehypertensive (12.8%), hypertensive (22.2%), and normotensive (65%). The overall prevalence of overweight, obesity, and abdominal obesity (if WC was in the ≥75th percentile) were 12.1%, 2.4%, and 9%, respectively. After adjusting for age and sex, significant associations were found between overweight and obesity and high BP, namely, prehypertension (overweight: aOR = 2.62; 95% CI 2.13–3.23; obesity: aOR = 4.81; 95% CI 3.08–7.52) and hypertension (overweight: aOR = 3.56; 95% CI 3.02–4.19; obesity: aOR = 6.64; 95% CI 4.65–9.49). Prehypertension was found to be significantly associated with WC in the 75th– < 90th percentiles (aOR = 3.16; 95% CI 2.43–4.10) and WC in the ≥90th percentile (aOR = 4.08; 95% CI 2.35–7.10). For hypertension, significant associations were detected with WC in the 75th– < 90th percentiles (aOR = 3.92; 95% CI 3.18–4.82) and WC in the ≥90th percentile (aOR = 7.41; 95% CI 4.97–11.05). CONCLUSIONS: Overweight, obesity, and abdominal obesity were associated with prehypertension and hypertension

ESTRESSE LABORAL DA EQUIPE DE ENFERMAGEM NOS SERVIÇOS DE URGÊNCIA E EMERGÊNCIA

O estresse é um problema atual da sociedade que traz impactos a vida pessoal e profissional dos trabalhadores. Sendo necessário, um estudo aborde a importância da qualidade de vida do enfermeiro no ambiente de trabalho, ressaltando o setor de urgência e emergência, pois possui uma dinâmica diferente. Dessa forma, o presente trabalho visa analisar a produção científica sobre o estresse dos profissionais de enfermagem no ambiente hospitalar de urgência e emergência. Além disso, o trabalho busca detectar quais as fontes geradoras do estresse, quais os sintomas do estresse laboral e indicar algumas propostas de intervenção para o estresse dos profissionais que atuam na área da saúde. A partir de uma revisão bibliográfica de caráter qualitativo e descritivo, analisando trabalhos publicados a partir de 2015. Assim, por meio desse conhecimento, os profissionais e a instituição devem buscar mecanismos que visem minimizar as fontes estressoras, com a finalidade de melhorar a qualidade da assistência prestada, bem como melhorar sua qualidade de vida. Pois, valorizando as relações de trabalho e ambiente, promove-se benefícios à saúde dos trabalhadores

CONTROLE E MONITORAMENTO INTERNO COM SOFTWARE DE GESTÃO DE REDE LOCAL

Technology is increasingly present everywhere, being part of the daily life of a large part of the population, being used for various purposes. Technological advancement is increasing and providing various means of improvement for various sectors of society. In the work environment, various systems and technological procedures are used to increase the flow of tasks, making it easier to manipulate information. In institutions and companies that make use of technologies to optimize and increase the flow of their routines, there is the Information Technology sector, responsible for organizing and monitoring operations related to equipment and hardware devices, and software systems, investing in means to evaluate and ensure greater safety performance within the work environment. Aiming at this high performance of technological use, monitoring the local network is one of the main factors that enable the optimization of technologies and resources used by users, analyzing the data transmitted and connections requested through the network by systems and users. Monitoring within a specific network allows evaluating and detecting anomalies, allowing greater control over resources, predicting risk situations and creating problem solutions.A tecnologia está cada vez mais presente em todos os lugares, fazendo parte da vida diária de grande parte da população, sendo utilizada para diversos objetivos. O avanço tecnológico está aumentando e proporcionado vários meios de aperfeiçoamento para diversos setores da sociedade. No ambiente de trabalho, se faz uso de vários sistemas e procedimentos tecnológicos para aumentar o fluxo de tarefas, propiciando maior facilidade de manipulação de informações. Em instituições e empresas que fazem uso de tecnologias para otimizar e aumentar o fluxo de suas rotinas, existe o setor de Tecnologia da Informação, responsabilizado em organizar e monitorar as operações relacionadas a equipamentos e dispositivos de hardware, e sistemas de software, investindo em meios de avaliar e garantir maior performance de segurança dentro do ambiente de trabalho. Visando esta alta performance de uso tecnológico, o monitoramento da rede local é um dos principais fatores que possibilitam a otimização das tecnologias e recursos utilizados por usuários, analisando os dados trafegados e conexões requisitadas através da rede por sistemas e usuários. O monitoramento dentro de uma rede especifica permite avaliar e detectar anomalias, permitindo um controle maior sobre recursos, prevendo situações de risco e criando soluções de problemas