Composite design bioinspired by the mesocarp of Brazil nut (Bertholletia excelsa).

The mesocarp ofBertholletia excelsais a rich source of inspiration for strong, stiff and damage-tolerant composites. The bioinspired composites developed here are composed of an epoxy matrix with a 3D printed polylactic acid reinforced with 30% of carbon fiber (PLA-30CF) inspired in fibers, and syntactic foam inspired by sclereids. Monotonic and cyclic four-point bending tests and compact tension fracture toughness tests were carried out assisted by digital image correlation (DIC) to evaluate flexural properties, damage tolerance, and theR-curve of the composite. Its microstructure and fracture surface were analyzed by scanning electron microscopy. The mechanical performance of the bioinspired composite is promising: density of 1.0 g cm-3, flexural apparent elastic modulus of 1.6 GPa, and flexural strength six times higher than the neat epoxy, i.e. 17 MPa. Although the PLA-30CF printed structure led to a risingR-curve, the syntactic foam needs optimization to have a synergistic effect.

Mesocarp of Brazil nut (Bertholletia excelsa) as inspiration for new impact resistant materials.

Aiming to produce bioinspired impact and puncture resistant materials, the mesocarp of the Brazil nut (Bertholletia excelsa) was characterized. The mesocarp composition was investigated by chemical extraction and its microstructure was analyzed by optical microscopy and microtomography (microCT). A compression test evaluated the force needed to open the mesocarp shell. Shore D hardness testing and nanoindentation measured the local mechanical properties at different length scales. Brazil nut mesocarp has a higher content of lignin (56%) than other nutshells and is mainly composed of sclereids and fibers cells arranged together and not in separated layers as usually found in nature. The mesocarp has an internal and external layer with fibers oriented from peduncle to opercular opening and a middle layer where entangled fibers are latitudinally oriented. To open a Brazil nut mesocarp, compression forces of 10 079 ± 1460 N (parallel to latitudinal section) and 14 785 ± 4050 N (perpendicular to latitudinal section) are needed. Such forces are higher than the forces needed to open most nutshells, if fracture force is normalized by shell thickness. The Shore D hardness test showed that hardness is uniform in the mesocarp, although it is higher in the center of the thickness than close to the inner or outer surface. The cell wall of fibers has a higher reduced modulus than the cell wall of sclereids although they have a similar hardness. These microstructural and mechanical results indicate that Brazil nutshell has great potential as a source for bioinspiration and motivates further studies.

Mental health in girls and boys exposed to intimate partner violence.

OBJECTIVES: Children of abused women have a greater risk of mental health problems. This study assesses the association between women's exposure to intimate partner violence (IPV) and the mental health of their children in the population of the Madrid Region. STUDY DESIGN: Cross-sectional. METHODS: Data were drawn from the '2014 Survey on Intimate Partner Violence against Women in the Madrid Region'. Women meeting the definition of IPV answered the Strengths and Difficulties Questionnaire (SDQ) on the mental health of one of their children aged 4-16 years. The comparison group was made up of mother-child dyads that had not been exposed to IPV. We used multivariate analysis to assess whether the children of abused women had a greater probability of having higher SDQ subscale and total scores. RESULTS: A total of 209 mother-child dyads were analyzed, 64 exposed (50% boys) and 145 unexposed to IPV (51% boys). Exposure to IPV was associated with a high SDQ score (greater risk of mental health problems), with a prevalence ratio of 3.6 (95% CI 1.2-10.3) in girls and 2.4 (95% CI 1.1-5.1) in boys. Among girls, moreover, exposure to IPV was significantly associated with behavioral and inattention/hyperactivity problems. In conclusion, exposure to IPV was associated with an increased frequency of mental health problems among children in general, and girls in particular. CONCLUSIONS: This study reinforces the recommendations to conduct studies with data disaggregated by sex and to address the impact of IPV in mothers and children jointly.

Clinical viability of single implant-retained mandibular overdentures: a systematic review and meta-analysis.

The aim of this meta-analysis was to verify the clinical viability of single implant-retained mandibular overdentures (SIMO). An electronic search of the PubMed and Cochrane databases was performed (end date July 2017); this was supplemented by a manual search of the literature. Only prospective clinical trials and randomized controlled trials (RCTs) that evaluated SIMO with a minimum follow-up of 12 months were included. The meta-analysis was based on the Mantel-Haenszel method. Dental implant and prosthetic failure were the dichotomous outcome measures; these were evaluated through the risk ratio (RR) and odds ratio (OR), with corresponding 95% confidence intervals (CI). Of 499 articles identified, nine fulfilled the inclusion criteria. A total of 205 implants were placed in patients with a mean age of 64.1 years; the cumulative survival rate was 96.6% over a mean follow-up period of 37.3 months. The procedure used (SIMO vs. two implant-retained mandibular overdenture) did not affect dental implant failure (P=0.45) or prosthetic failure (P=0.65): RR 1.06 (95% CI 0.91-1.23) and RR 0.88 (95% CI 0.51-1.51), respectively; OR 2.56 (95% CI 0.27-24.39; P=0.41) and OR 0.44 (95% CI 0.15-1.26; P=0.13), respectively. Within the limitations of this systematic review and meta-analysis, SIMO with a complete denture as the opposing arch may be considered an alternative treatment for completely edentulous patients. However, this study also confirmed the need for more RCTs on this topic.

BDNF mRNA splice variants display activity-dependent targeting to distinct hippocampal laminae.

Brain-derived neurotrophic factor (BDNF) may exert contrasting effects depending on its different subcellular sites of action (soma, dendrites, axons). These contrasting effects may explain contradictory findings, for example that BDNF may favour or oppose epileptogenesis. We determined the distribution of five BDNF splice variants in the soma and dendrites of rat hippocampal principal neurons, after application of stimuli that prompt BDNF mRNA accumulation in dendrites (epileptogenic seizures). Under basal conditions, no BDNF mRNA splice variant was detectable in dendrites, while specific splice variants were found in dendrites in response to epileptogenic seizures. Three hours after pilocarpine administration, exon VI and exon II splice variants were found in dendrites, while exons I and IV transcripts displayed a strictly somatic localization. Three hours after kainate administration, only exon VI was found in dendrites. These data suggest that the regulated expression of different splice variants may provide a spatial code to ensure the delivery of BDNF to precise destinations in the cell soma or along the dendrites.

Twist is substrate for caspase cleavage and proteasome-mediated degradation.

Twist is a member of the basic helix-loop-helix family of transcription factors. An aberrant Twist expression has been found in diverse types of cancer, including sarcomas, carcinomas and lymphomas, supporting a role for Twist in tumor progression. Twist is known to be essential for mesodermal development. However, since a prolonged Twist expression results in a block of muscle, cartilage and bone differentiation, Twist has to be excluded from somites during late embryogenesis for terminal differentiation to occur. This implies that Twist expression must be target of a tight control. Here we provide evidence that Twist undergoes post-transcriptional regulation. Twist is substrate for cleavage by caspases during apoptosis and its cleavage results in ubiquitin-mediated proteasome degradation. Our findings suggest that Twist post-transcriptional regulation may play an important role in tissue determination and raise the possibility that alterations in the protein turnover may account for Twist overexpression observed in tumors.

Autologous bone marrow transplantation for acute lymphoblastic leukemia: the high dose vincristine study of AIEOP BMT group.

This study was performed in 5 pediatric centers. It considered a group of children affected by acute lymphoblastic leukemia (ALL) treated with ABMT. 56 patients were considered, 35 males and 21 females, with a median age of 11 years. The children were transplanted in 2nd (36) or subsequent (20) complete remission. The mean of 1st remission duration was 32 months. Analysis of the sites of relapse before transplantation showed that 39 patients had bone marrow relapses, 17 patients had CNS and/or testicular isolated relapses only. 32 harvests were purged in vitro by 1 mcgr/ml Vincristine and 30 mcgr/ml Prednisone, 16 by 100 mcgr/ml Mafosfamide, 8 were not cleaned. 29 patients received high dose Vincristine (4 mg/m2), TBI (1200 cGy), Cyclophosphamide (3600 mg/m2) as standard conditioning regimen before transplant. 27 patients received other conditioning treatments with (14) or without (13) TBI. Of the 56 children 25 relapsed from 1 to 42 months after ABMT, 7 toxicity related deaths were registered and 1 death for second tumor was observed. 23 children remained in continuous complete remission from 1 to 49 months after transplantation. The probability of EFS at 4 years was 21%. High dose Vincristine did not statistically improve the EFS, but a trend was observed (44% versus 0%). Vincristine, Asta-Z or none purging did not show any significant effect on EFS (37% vs 32% vs 0%). On the contrary when the EFS was related to the site of relapse, isolated or sistemic, the difference was almost statistically significant (46% vs 18%). The analysis of our results indicates the isolated relapse as good prognostic factor in ABMT for ALL and high dose Vincristine associated to conditioning regimen as worthy of further investigations.