On the mechanical, electronic, and optical properties of the boron nitride analog for the recently synthesized biphenylene network: a DFT study.

CONTEXT: Recently, a new 2D carbon allotrope named biphenylene network (BPN) was experimentally realized. Here, we use density functional theory (DFT) calculations to study its boron nitride analogue sheet's structural, electronic, and optical properties (BN-BPN). Results suggest that BN-BPN has good structural and dynamic stabilities. It also has a direct bandgap of 4.5 eV and significant optical activity in the ultraviolet range. BN-BPN Young's modulus varies between 234.4[Formula: see text]273.2 GPa depending on the strain direction. METHODS: Density functional theory (DFT) simulations for the electronic and optical properties of BN-BPN were performed using the CASTEP package within the Biovia Materials Studio software. The exchange and correlation functions are treated within the generalized gradient approximation (GGA) as parameterized by Perdew-Burke-Ernzerhof (PBE) and the hybrid functional Heyd-Scuseria-Ernzerhof (HSE06). For convenience, the mechanical properties were carried out using the DFT approach implemented in the SIESTA code, also within the scope of the GGA/PBE method. We used the double-zeta plus polarization (DZP) for the basis set in these cases. Moreover, the norm-conserving Troullier-Martins pseudopotential was employed to describe the core electrons.

Environmental and anthropic variabilities at Guanabara Bay (Brazil): A comparative perspective of metal depositions in different time scales during the last 5,500 yrs.

The determination of age-dated metal sediment accumulation rates in a representative South American bay is able to portray the dimension of human impacts during the colonial occupation and industrial periods. Many studies have assessed metal distribution and chronology at Guanabara Bay, in Brazil. However, understanding natural variabilities associated to paleoclimatic changes and comparing these natural variabilities to anthropogenic processes are not well established to date. Accurate geochronological control integrating ages determined by 210Pb and 14C chronologies through an exponential spline fit model allowed for a precise definition of changes associated to the holocene marine transgression, as well as the colonial period, leading to intense land use changes, and the industrial period. The reference values of the system were defined based on their concentrations and the accumulation rates of ecotoxicologically important metals. Al, Ba, Fe, Cd, Cu, Cr, Li, Ni, Mn, Pb, Si, Ti, V, and Zn distributions were determined in a Guanabara Bay core (BG-28) by the EPA 3051 method. Elemental distribution profile assessment allowed for the identification of variabilities associated to weathering processes, predominantly of lithogenic origin, mainly for Al, Ba, Fe, Li, Si, and V. Weathering processes occurred simultaneously to land use changes in the drainage basin since the colonial period, at 400 cal yr BP, and during the industrial period, mainly after the 1960s, denoted by Cd, Cr, Cu, Mn, Pb and Zn increases. The highest average metal enrichment values metals associated to industrial processes reached 5.95, with 119.1-fold higher accumulation rates than the background accumulation values observed between 4200 and 500 cal yr BP.

Smith-Magenis syndrome: clinical evaluation in seven Brazilian patients.

Smith-Magenis syndrome (SMS) is a complex congenital anomaly characterized by craniofacial anomalies, neurological and behavioral disorders. SMS is caused by a deletion in region 17p11.2, which includes the RAI1 gene (90% of cases), or by point mutation in the RAI1 gene (10% of cases). Laboratory diagnosis is through cytogenetic analysis by GTG banding and molecular cytogenetic analysis by FISH. We carried out an active search for patients in Associations of Parents and Friends of Exceptional Children (APAE) of São Paulo and genetic centers in Brazil. Forty-eight patients were screened for mental retardation, craniofacial abnormalities and stereotyped behavior with a diagnosis of SMS. In seven of them, chromosome banding at high resolution demonstrated chromosome 17p11.2 deletions, confirmed by FISH. We also made a meta-analysis of 165 cases reported between 1982 and 2010 to compare with the clinical data of our sample. We demonstrated differences between the frequencies of clinical signs among the cases reported and seven Brazilian cases of this study, such as dental anomalies, strabismus, ear infections, deep hoarse voice, hearing loss, and cardiac defects. Although the gold standard for diagnosis of SMS is FISH, we found that the GTG banding technique developed to evaluate chromosome 17 can be used for the SMS diagnosis in areas where the FISH technique is not available.

Analysis of postural oscillation in children with cerebral palsy.

It is believed that static balance undergoes changes in children with cerebral palsy (CP). Thus, we analyzed postural oscillation in 19 children with the aim of comparing balance between healthy children and those with CP. The sample was divided into two groups--one with 10 children diagnosed with diparetic CP (CPG) and a control group (CG) with nine healthy children, all capable of remaining in an orthostatic position without support and obeying spoken commands. The assessment of postural oscillation was performed with the children barefoot, arms alongside the body and looking toward a fixed point while standing on an unrestricted base for the feet. Data collection was performed using a TEKScan force platform with 30-second duration for each condition. The children had an average age of 7.9 years (+/- 2.07) in the CPG and 7.5 years (+/- 1.58) for the CG. Postural oscillation data in the anterior-posterior and medial-lateral directions were analyzed using the Data Analysis and Technical Graphics Origin 6.0 program. Statistical analysis of the mean oscillation value in the conditions of eyes open and eyes closed did not differ significantly between groups. However, there was a significant difference in mean anterior-posterior oscillation between groups (p = 0.00). The groups behaved similarly with regard to the visual deprivation. We conclude that children with CP exhibit less postural oscillation in comparison to healthy children under the same conditions.

Vitis vinifera must varietal authentication using microsatellite DNA analysis (SSR).

A microsatellite DNA-based method for Vitis vinifera grape must authentication is presented. Five of the most important port wine producing grape cultivars (Tinta Roriz, Tinto Cão, Touriga Francesa, Touriga Nacional, and Tinta Barroca) were typed at four microsatellite loci described by Bowers et al. (Genome 1996, 39, 628-633) and Thomas and Scott (Theor. Appl. Genet. 1993, 86, 985-990). The corresponding 5 varietal musts and 26 must mixtures that result from the combination of the five varieties were also typed at the four loci. There were no differences between the corresponding leaf and varietal must profiles. All must combinations showed the expected band profiles corresponding to the sum of the varietal band profile components. Among the 26 must mixtures, 8 could be discriminated using the four loci.