Modelling mitral valvular dynamics–current trend and future directions

Dysfunction of mitral valve causes morbidity and premature mortality and remains a leading medical problem worldwide. Computational modelling aims to understand the biomechanics of human mitral valve and could lead to the development of new treatment, prevention and diagnosis of mitral valve diseases. Compared with the aortic valve, the mitral valve has been much less studied owing to its highly complex structure and strong interaction with the blood flow and the ventricles. However, the interest in mitral valve modelling is growing, and the sophistication level is increasing with the advanced development of computational technology and imaging tools. This review summarises the state-of-the-art modelling of the mitral valve, including static and dynamics models, models with fluid-structure interaction, and models with the left ventricle interaction. Challenges and future directions are also discussed

Decrease in Sperm Quality due to Infection of Human Papilloma Virus and Chlamydia trachomatis

Male infertility can have different causes, one of which may be the presence of etiologic agents that cause sexually transmitted infections. Among the most important sexually transmitted infections are human papillomavirus and Chlamydia trachomatis, which are as‐ sociated with infertility in females – whether they cause infertility in men is controversial. The purpose of the chapter is to review the effect of these two pathogens on male fertility, the evidence suggests that the most important infertility effect is linked to the condition of the sperm. However, it is noteworthy that there are few studies with respect to infertil‐ ity in regard to both pathogens, so it is important to further research this to elucidate the mechanisms by which these pathogens act on male infertility.UNIVERSIDAD AUTÓNOMA DEL ESTADO DE MÉXIC

Multifaceted modelling of complex business enterprises

We formalise and present a new generic multifaceted complex system approach for modelling complex business enterprises. Our method has a strong focus on integrating the various data types available in an enterprise which represent the diverse perspectives of various stakeholders. We explain the challenges faced and define a novel approach to converting diverse data types into usable Bayesian probability forms. The data types that can be integrated include historic data, survey data, and management planning data, expert knowledge and incomplete data. The structural complexities of the complex system modelling process, based on various decision contexts, are also explained along with a solution. This new application of complex system models as a management tool for decision making is demonstrated using a railway transport case study. The case study demonstrates how the new approach can be utilised to develop a customised decision support model for a specific enterprise. Various decision scenarios are also provided to illustrate the versatility of the decision model at different phases of enterprise operations such as planning and control

Safer Prescribing:A Trial of Education, Informatics, and Financial Incentives

BACKGROUND High-risk prescribing and preventable drug-related complications are common in primary care. We evaluated whether the rates of high-risk prescribing by primary care clinicians and the related clinical outcomes would be reduced by a complex intervention. METHODS In this cluster-randomized, stepped-wedge trial conducted in Tayside, Scotland, we randomly assigned participating primary care practices to various start dates for a 48-week intervention comprising professional education, informatics to facilitate review, and financial incentives for practices to review patients’ charts to assess appropriateness. The primary outcome was patient-level exposure to any of nine measures of high-risk prescribing of nonsteroidal antiinflammatory drugs (NSAIDs) or selected antiplatelet agents (e.g., NSAID prescription in a patient with chronic kidney disease or coprescription of an NSAID and an oral anticoagulant without gastroprotection). Prespecified secondary outcomes included the incidence of related hospital admissions. Analyses were performed according to the intention-to-treat principle, with the use of mixed-effect models to account for clustering in the data. RESULTS A total of 34 practices underwent randomization, 33 of which completed the study. Data were analyzed for 33,334 patients at risk at one or more points in the preintervention period and for 33,060 at risk at one or more points in the intervention period. Targeted high-risk prescribing was significantly reduced, from a rate of 3.7% (1102 of 29,537 patients at risk) immediately before the intervention to 2.2% (674 of 30,187) at the end of the intervention (adjusted odds ratio, 0.63; 95% confidence interval [CI], 0.57 to 0.68; P<0.001). The rate of hospital admissions for gastrointestinal ulcer or bleeding was significantly reduced from the preintervention period to the intervention period (from 55.7 to 37.0 admissions per 10,000 person-years; rate ratio, 0.66; 95% CI, 0.51 to 0.86; P = 0.002), as was the rate of admissions for heart failure (from 707.7 to 513.5 admissions per 10,000 person-years; rate ratio, 0.73; 95% CI, 0.56 to 0.95; P = 0.02), but admissions for acute kidney injury were not (101.9 and 86.0 admissions per 10,000 person-years, respectively; rate ratio, 0.84; 95% CI, 0.68 to 1.09; P = 0.19). CONCLUSIONS A complex intervention combining professional education, informatics, and financial incentives reduced the rate of high-risk prescribing of antiplatelet medications and NSAIDs and may have improved clinical outcomes

Concomitant Carcinoma in situ in Cystectomy Specimens Is Not Associated with Clinical Outcomes after Surgery

Objective: The aim of this study was to externally validate the prognostic value of concomitant urothelial carcinoma in situ (CIS) in radical cystectomy (RC) specimens using a large international cohort of bladder cancer patients. Methods: The records of 3,973 patients treated with RC and bilateral lymphadenectomy for urothelial carcinoma of the bladder (UCB) at nine centers worldwide were reviewed. Surgical specimens were evaluated by a genitourinary pathologist at each center. Uni- and multivariable Cox regression models addressed time to recurrence and cancer-specific mortality after RC. Results: 1,741 (43.8%) patients had concomitant CIS in their RC specimens. Concomitant CIS was more common in organ-confined UCB and was associated with lymphovascular invasion (p < 0.001). Concomitant CIS was not associated with either disease recurrence or cancer-specific death regardless of pathologic stage. The presence of concomitant CIS did not improve the predictive accuracy of standard predictors for either disease recurrence or cancer-specific death in any of the subgroups. Conclusions: We could not confirm the prognostic value of concomitant CIS in RC specimens. This, together with the discrepancy between pathologists in determining the presence of concomitant CIS at the morphologic level, limits the clinical utility of concomitant CIS in RC specimens for clinical decision-making. Copyright (C) 2011 S. Karger AG, Base

Ionic high-pressure form of elemental boron

Boron is an element of fascinating chemical complexity. Controversies have shrouded this element since its discovery was announced in 1808: the new 'element' turned out to be a compound containing less than 60-70 percent of boron, and it was not until 1909 that 99-percent pure boron was obtained. And although we now know of at least 16 polymorphs, the stable phase of boron is not yet experimentally established even at ambient conditions. Boron's complexities arise from frustration: situated between metals and insulators in the periodic table, boron has only three valence electrons, which would favour metallicity, but they are sufficiently localized that insulating states emerge. However, this subtle balance between metallic and insulating states is easily shifted by pressure, temperature and impurities. Here we report the results of high-pressure experiments and ab initio evolutionary crystal structure predictions that explore the structural stability of boron under pressure and, strikingly, reveal a partially ionic high-pressure boron phase. This new phase is stable between 19 and 89 GPa, can be quenched to ambient conditions, and has a hitherto unknown structure (space group Pnnm, 28 atoms in the unit cell) consisting of icosahedral B12 clusters and B2 pairs in a NaCl-type arrangement. We find that the ionicity of the phase affects its electronic bandgap, infrared adsorption and dielectric constants, and that it arises from the different electronic properties of the B2 pairs and B12 clusters and the resultant charge transfer between them.Comment: Published in Nature 453, 863-867 (2009

Draft Genome Sequence of Methylocella silvestris TVC, a Facultative Methanotroph Isolated from Permafrost

Permafrost environments play a crucial role in global carbon and methane cycling. We report here the draft genome sequence of Methylocella silvestris TVC, a new facultative methanotroph strain, isolated from the Siksik Creek catchment in the continuous permafrost zone of Inuvik (Northwest Territories, Canada)