BxCyNz hybrid graphenylene: stability and electronic properties

Interest in hybrid monolayers with arrangements that differ from that of the honeycomb lattice has been growing. However, systematic investigations on the properties of these structures are still lacking. In this work, we combined density functional theory (DFT) and molecular dynamics (MD) simulations to study the stability and electronic properties of nanosheets composed of B, C, and N atoms arranged in the pattern of the carbon allotrope graphenylene. We considered twenty structures with varied atomic arrangements and stoichiometries, which we call B_xC_yN_z hybrid graphenylenes. We calculated the formation energy for each arrangement, and found that it decreases as the number of B–C and N–C bonds decreases. We also found that the structure with minimum energy has stoichiometry B₂CN and an atomic arrangement with BN and C stripes connected along the zigzag direction. Regarding the electronic properties, we found that all investigated structures are semiconductors, with band gaps ranging from 0.14 to 1.65 eV. Finally, we found that the optimized hybrid lattices presented pores of varied sizes and shapes. This diversity in pore geometry suggests that these structures might be particularly suited for molecular sieve applications.

We combine density functional theory and molecular dynamics to investigate the stability and electronic properties of 20 structures composed of boron, carbon, and nitrogen arranged in the pattern of the two-dimensional carbon allotrope graphenylene.     

Spatiotemporal Patterns of Schistosomiasis-Related Deaths,Brazil, 2000–2011

We analyzed spatiotemporal patterns of 8,756 schistosomiasis-related deaths in Brazil during 2000–2011 and identified high-risk clusters of deaths, mainly in highly schistosomiasis-endemic areas along the coast of Brazil’s Northeast Region. Schistosomiasis remains a neglected public health problem with a high number of deaths in disease-endemic and emerging focal areas.     

Water-based resistance training program with isolated concentric action improves physical functional capacity and muscular strength in older women

Background

Resistance training has proven to be an excellent method for counteracting aging physical dysfunctions. However, its application in the liquid environment is not yet fully elucidated.

Aim

To investigate the effects of water-based resistance training (WBRT) with the concentric phase performed as fast as possible, compared to conventional resistance training (CRT), on physical functional capacity, muscle strength, and body composition in older women.

Methods

Thirteen healthy older women participated in the WBRT and 11 in the CRT. Estimation statistics focused on the effect size of the experiment/intervention were used. We also analyzed the intervention effect based on the percentage delta between WBRT and CRT.

Results

The WBRT group showed a negative large effect (d?=?? 0.922; p?=?0.0274) for the timed up and go, and a large effect for chair rise in 30″ and the elbow flex test (d?=?1.58; p?=?0.0012; d?=?2.8; p?=?0.01) respectively. Intervention comparisons based on the delta percentage between WBRT and CRT presented an intermediate effect (d?=?0.606; p?=?0.157) for the stair climb, a large effect (d?=?0.988; p?=?0.0282) for the timed up and go, and a large negative effect [d?=?? 1.32 (90.0% CI ? 1.92, ? 0.646); p?=?0.0038] for the elbow flex test. Concentric extensor-flexor peak torque (60°/s) showed an intermediate effect (d?=?0.749; p?=?0.0876; d?=?0.65; p?=?0.122 respectively). Body fat (%) demonstrated an intermediate effect (d?=?0.523; p?=?0.234).

Conclusion

WBRT with the concentric phase performed as fast as possible was able to improve physical functional capacity and maximal knee extension strength of older women.

     

Myopodin is an F-actin bundling protein with multiple independent actin-binding regions

The assembly of striated muscle myofibrils is a multistep process in which a variety of proteins is involved. One of the first and most important steps in myofibrillogenesis is the arrangement of thin myofilaments into ordered I-Z-I brushes, requiring the coordinated activity of numerous actin binding proteins. The early expression of myopodin prior to sarcomeric α-actinin, as well as its binding to actin, α-actinin and filamin indicate an important role for this protein in actin cytoskeleton remodelling with the precise function of myopodin in this process yet remaining to be resolved. While myopodin was previously described as a protein capable of cross-linking actin filaments into thick bundles upon transient transfections, it has remained unclear whether myopodin alone is capable of bundling actin, or if additional proteins are involved. We have therefore investigated the in vitro actin binding properties of myopodin. High speed cosedimentation assays with skeletal muscle actin confirmed direct binding of myopodin to F-actin and showed that this interaction is mediated by at least two independent actin binding sites, found in all myopodin isoforms identified to date. Furthermore, low-speed cosedimentation assays revealed that not only full length myopodin, but also the fragment containing only the second binding site, bundles microfilaments in the absence of accessory proteins. Ultrastructural analysis demonstrated that this bundling activity resembled that of α-actinin. Biochemical experiments revealed that bundling was not achieved by myopodin’s ability to dimerize, indicating the presence of two individual F-actin binding sites within the second binding segment. Thus full length myopodin contains at least three F-actin binding sites. These data provide further understanding of the mechanisms by which myopodin contributes to actin reorganization during myofibril assembly.

     

Evaluation of risk factors in superobese patients submitted to conventional Fobi-Capella surgery

BACKGROUND: Obesity is one of the worlds greatest health problems. The Roux-en-Y gastric bypass is the gold standard treatment for severe obesity. Surgery in obese patients has an acceptable level of morbidity and mortality. The superobese patient, a subcategory of severe obese patients with a high surgical risk has not yet been analyzed as a group. METHODS: A retrospective and prospective cohort study was conducted enrolling 135 patients submitted to Roux-en-Y gastric bypass for treatment of severe obesity at the " Hospital das Clínicas" , Federal University of Pernambuco, Recife, PE, Brazil, between November 1997 and September 2003. The independent variables were possible risk factors of adverse outcomes: age, gender, weight, body mass index, diabetes, hypertension, hypercholesterolemia, sleep apnea, cardiopathy/coronariopathy, pneumopathy or any other co-morbidity. The dependent variables were major complications, minor complications and death. RESULTS: Diabetes (RR = 1.6 and CI = 1.02-2.40) and sleep apnea (RR = 1.8 and CI = 1.18-2.64) were associated to minor complications. Cardiopathy/coronariopathy were associated with major complications (RR = 5.42 and CI = 1.22-2.40) and death (RR = 16.25 and CI = 3.00-87.95). BMI >or=55 kg/m2 was associated with minor complications (RR = 1.58 and CI = 1.04-2.40), major complications (RR = 3.17 and CI = 1.03-9.80) and death (P = 0.007). After logistic regression, the body mass index >55 kg/m2 remained as a strong risk factor of death (OR = 3.6 and CI = 1.05-12.32). CONCLUSIONS: The body mass index >or=55 kg/m2 was the main risk factor for severe complications and death. Other risk factors affecting the outcome were diabetes, obstructive sleep apnea and cardiopathy/coronariopathy.