Symmetry insights for design of supercomputer network topologies: roots and weights lattices

We present a family of networks whose local interconnection topologies are generated by the root vectors of a semi-simple complex Lie algebra. Cartan classification theorem of those algebras ensures those families of interconnection topologies to be exhaustive. The global arrangement of the network is defined in terms of integer or half-integer weight lattices. The mesh or torus topologies that network millions of processing cores, such as those in the IBM BlueGene series, are the simplest member of that category. The symmetries of the root systems of an algebra, manifested by their Weyl group, lends great convenience for the design and analysis of hardware architecture, algorithms and programs.

The Influence of Osteoblast Differentiation Stage on Bone Formation in Autogenously Implanted Cell-Based Poly(Lactide-Co-Glycolide) and Calcium Phosphate Constructs

We tested the hypothesis that the osteoblast differentiation status of bone marrow stem cells (BMSCs) combined with a three-dimensional (3D) structure modulates bone formation when autogenously implanted. Rat BMSCs were aspirated, expanded, and seeded into a 3D composite of poly(lactide-co-glycolide) and calcium phosphate (PLGA/CaP) to produce a hybrid biomaterial. Calvarial defects were implanted with (1) scaffold without cells (SC/NC), (2) scaffold and BMSCs (SC + BMSC), (3) scaffold and osteoblasts differentiated for 7 days (SC + OB7), and (4) for 14 days (SC + OB14). After 4 weeks, there was more bone formation in groups combining scaffold and cells, SC + BMSC and SC + OB7. A nonsignificant higher amount of bone formation was observed on SC + OB14 compared with SC/NC. Additionally, more blood vessels were counted within all hybrid biomaterials, without differences among them, than into SC/NC. These findings provide evidences that the cell differentiation status affects in vivo bone formation in autogenously implanted cell-based constructs. Undifferentiated BMSCs or osteoblasts in early stage of differentiation combined with PLGA/CaP scaffold favored bone formation compared with plain scaffold and that one associated with more mature osteoblasts.

RHYTHM-AF: design of an international registry on cardioversion of atrial fibrillation and characteristics of participating centers

Background: Atrial fibrillation is a serious public health problem posing a considerable burden to not only patients, but the healthcare environment due to high rates of morbidity, mortality, and medical resource utilization. There are limited data on the variation in treatment practice patterns across different countries, healthcare settings and the associated health outcomes. Methods/design: RHYTHM-AF was a prospective observational multinational study of management of recent onset atrial fibrillation patients considered for cardioversion designed to collect data on international treatment patterns and short term outcomes related to cardioversion. We present data collected in 10 countries between May 2010 and June 2011. Enrollment was ongoing in Italy and Brazil at the time of data analysis. Data were collected at the time of atrial fibrillation episode in all countries (Australia, Brazil, France, Germany, Italy, Netherlands, Poland, Spain, Sweden, United Kingdom), and cumulative follow-up data were collected at day 60 (+/- 10) in all but Spain. Information on center characteristics, enrollment data, patient demographics, detail of atrial fibrillation episode, medical history, diagnostic procedures, acute treatment of atrial fibrillation, discharge information and the follow-up data on major events and rehospitalizations up to day 60 were collected. Discussion: A total of 3940 patients were enrolled from 175 acute care centers. 70.5% of the centers were either academic (44%) or teaching (26%) hospitals with an overall median capacity of 510 beds. The sites were mostly specialized with anticoagulation clinics (65.9%), heart failure (75.1%) and hypertension clinics (60.1%) available. The RHYTHM-AF registry will provide insight into regional variability of antiarrhythmic and antithrombotic treatment of atrial fibrillation, the appropriateness of such treatments with respect to outcomes, and their cost-efficacy. Observations will help inform strategies to improve cardiovascular outcomes in patients with atrial fibrillation.

Development of Cationic Solid Lipid Nanoparticles with Factorial Design-Based Studies for Topical Administration of Doxorubicin

Topical chemotherapy using doxorubicin, a powerful anticancer drug, can be used as an alternative with reduced systemic toxicity when treating skin cancer. The aim of the present work was to use factorial design-based studies to develop cationic solid lipid nanoparticles containing doxorubicin; further investigations into the influence of these particles on the drug's cytotoxicity and cellular uptake in B16F10 murine melanoma cells were performed. A 3(2) full factorial design was applied for two different lipid phases; one phase used stearic acid and the other used a 1:2 mixture of stearic acid and glyceryl behenate. The two factors investigated included the ratio between the lipid and the water phase and the ratio between the surfactant (poloxamer) and the co-surfactant (cetylpyridinium chloride). It was observed that the studied factors did not affect the mean diameter or the polydispersity of the obtained nanoparticles; however, they did significantly affect the zeta potential values. Optimised formulations with particle sizes ranging from 251 to 306 nm and positive zeta potentials were selected for doxorubicin incorporation. High entrapment efficiencies were achieved (97%) in formulations with higher amounts of stearic acid, suggesting that cationic charges on doxorubicin molecules may interact with the negative charges in stearic acid. Melanoma culture cell experiments showed that cationic solid lipid nanoparticles without drug were not cytotoxic to melanoma cells. The encapsulation of doxorubicin significantly increased cytotoxicity, indicating the potential of these nanoparticles for the treatment of skin cancer.

Development of an integrative cessation program for co-smokers of cigarettes and cannabis: demand analysis, program description, and acceptability

Abstract Background Tobacco and cannabis use are strongly interrelated, but current national and international cessation programs typically focus on one substance, and address the other substance either only marginally or not at all. This study aimed to identify the demand for, and describe the development and content of, the first integrative group cessation program for co-smokers of cigarettes and cannabis. Methods First, a preliminary study using expert interviews, user focus groups with (ex-)smokers, and an online survey was conducted to investigate the demand for, and potential content of, an integrative smoking cessation program (ISCP) for tobacco and cannabis co-smokers. This study revealed that both experts and co-smokers considered an ISCP to be useful but expected only modest levels of readiness for participation.Based on the findings of the preliminary study, an interdisciplinary expert team developed a course concept and a recruitment strategy. The developed group cessation program is based on current treatment techniques (such as motivational interviewing, cognitive behavioural therapy, and self-control training) and structured into six course sessions.The program was evaluated regarding its acceptability among participants and course instructors. Results Both the participants and course instructors evaluated the course positively. Participants and instructors especially appreciated the group discussions and the modules that were aimed at developing personal strategies that could be applied during simultaneous cessation of tobacco and cannabis, such as dealing with craving, withdrawal, and high-risk situations. Conclusions There is a clear demand for a double cessation program for co-users of cigarettes and cannabis, and the first group cessation program tailored for these users has been developed and evaluated for acceptability. In the near future, the feasibility of the program will be evaluated. Trial registration Current Controlled Trials ISRCTN15248397

Parametric study of retangular patch antenna using denim textile material

—This paper presents a textile patch antenna designed for WBAN applications at 2.45 GHz ISM band. The antenna uses denim as substrate and conductive fabric for the ground plane and radiator layers. The main purpose of this paper is to analyze the influence of typical deviation of denim properties and patch radiator dimensions on the performance of the antenna. The parameters considered in the analysis are the relative permittivity and thickness of denim and the width and length of the rectangular patch radiator. The dependence of the central operation frequency of the antenna on those parameters was studied using the antenna reflection coefficient obtained from EM simulations. Rules of thumb for one-shot design were derived and applied to design a rectangular patch antenna. An antenna prototype was fabricated and measured, demonstrating a 10 dB impedance band of 4.8 % centered at 2.45 GHz, in good agreement with simulated results