Crashworthiness of a composite bladder fuel tank for a tilt rotor aircraft

The fulfilment of the crash is a demanding requirement for a Tiltrotor. Indeed, such a kind of aircraft, being a hybrid between an airplane and a helicopter, inherits the requirements mainly from helicopters (EASA CS 29) due to its hovering ability. In particular, the fuel storage system must be designed in such a manner that it is crash resistant, under prescribed airworthiness requirements, in order to avoid the fuel leakage during such an event, preventing fire and, thus, increasing the survival chances of the crew and the passengers. The present work deals with the evaluation of crashworthiness of the fuel storage system of a Tiltrotor (bladder tank), and, in particular, it aims at describing the adopted numerical approach and some specific results. Crash resistance requirements are considered from the earliest design stages, and for this reason they are mainly addressed from a numerical point of view and by simulations that treat both single components and small/medium size assemblies. The developed numerical models include all the main parts needed for simulating the structural behavior of the investigated wing section: the tank, the structural components of the wing, the fuel sub-systems (fuel lines, probes, etc.) and the fuel itself. During the crash event there are several parts inside the tanks that can come into contact with the tank structure; therefore, it is necessary to evaluate which of these parts can be a damage source for the tank itself and could generate fuel loss. The SPH approach has been adopted to discretise fuel and to estimate the interaction forces with respect to the tank structure. Experimental data were used to calibrate the fuel tank and foam material models and to define the acceleration time-history to be applied. Thanks to the optimized foam’s configuration, the amount of dissipated impact energy is remarkable, and the evaluation of tanks/fuel system stress distribution allows estimating any undesired failure due to a survivable crash event

Protonation state of glutamate 73 regulates the formation of a specific dimeric association of mVDAC1.

The voltage-dependent anion channel (VDAC) is the most abundant protein in the outer mitochondrial membrane and constitutes the primary pathway for the exchange of ions and metabolites between the cytosol and the mitochondria. There is accumulating evidence supporting VDAC's role in mitochondrial metabolic regulation and apoptosis, where VDAC oligomerization has been implicated with these processes. Herein, we report a specific pH-dependent dimerization of murine VDAC1 (mVDAC1) identified by double electron-electron resonance and native mass spectrometry. Intermolecular distances on four singly spin-labeled mVDAC1 mutants were used to generate a model of the low-pH dimer, establishing the presence of residue E73 at the interface. This dimer arrangement is different from any oligomeric state previously described, and it forms as a steep function of pH with an apparent pKa of 7.4. Moreover, the monomer-dimer equilibrium affinity constant was determined using native MS, revealing a nearly eightfold enhancement in dimerization affinity at low pH. Mutation of E73 to either alanine or glutamine severely reduces oligomerization, demonstrating the role of protonated E73 in enhancing dimer formation. Based on these results, and the known importance of E73 in VDAC physiology, VDAC dimerization likely plays a significant role in mitochondrial metabolic regulation and apoptosis in response to cytosolic acidification during cellular stress

Vitamin d deficiency induces chronic pain and microglial phenotypic changes in mice

The bioactive form of vitamin .D, 1,25‐dihydroxyvitamin D (1,25D3), exerts immunomodulatory actions resulting in neuroprotective effects potentially useful against neurodegenerative and autoimmune diseases. In fact, vitamin D deficiency status has been correlated with painful manifestations associated with different pathological conditions. In this study, we have investigated the effects of vitamin D deficiency on microglia cells, as they represent the main immune cells responsible for early defense at central nervous system (CNS), including chronic pain states. For this purpose, we have employed a model of low vitamin D intake during gestation to evaluate possible changes in primary microglia cells obtained from postnatal day(P)2‐ 3 pups. Afterwards, pain measurement and microglia morphological analysis in the spinal cord level and in brain regions involved in the integration of pain perception were performed in the parents subjected to vitamin D restriction. In cultured microglia, we detected a reactive—activated and proliferative—phenotype associated with intracellular reactive oxygen species (ROS) generation. Oxidative stress was closely correlated with the extent of DNA damage and increased β‐galactosidase (B‐gal) activity. Interestingly, the incubation with 25D3 or 1,25D3 or palmitoylethanolamide, an endogenous ligand of peroxisome proliferator‐activated‐receptor‐alpha (PPAR‐α), reduced most of these effects. Morphological analysis of ex‐vivo microglia obtained from vitamin‐D‐deficient adult mice revealed an increased number of activated microglia in the spinal cord, while in the brain microglia appeared in a dystrophic phenotype. Remarkably, activated (spinal) or dystrophic (brain) microglia were detected in a prominent manner in females. Our data indicate that vitamin D deficiency produces profound modifications in microglia, suggesting a possible role of these cells in the sensorial dysfunctions associated with hypovitaminosis D

MEDICINES WASTE POLICIES AND THE POPULATION KNOWLEDGE IN BRAZIL

Objective: To investigate the degree of knowledge of the patients enrolled in the Unified Health System of the Medicine School of ABC (Faculdade de Medicina do ABC) regarding the proper use and disposal of medicaments. Methods: Participants were recruited for convenience, during their medical appointments at the clinic of the Medical School of ABC (Santo André, Sao Paulo, Brazil) in the period from 04 August to 30 September 2014. Data collection was conducted through a self-administered poll designed specifically for the purpose of this study, which consisted of 25 questions multiple choice about socioeconomic issues and the subject disposal of drugs, consumption and environmental pollution. Results: We selected the 140 patients’ polls. Most of them is of white ethnicity (58%) and female (58%). Level of education: 31% have completed secondary education (31%) or incomplete graduation (19%). Most of the participants (76%) buy drugs without a prescription, and most families (76%) seek understanding by reading the labels. 71.43% reported knowing that incorrect disposal of drugs could contaminate the environment, but 78% reported never having seen or received information about these. After using, 22.15% maintains the medication at home for future use, 55% of subjects reported improper disposal sites and 13% are delivered in health care institutions. Conclusion: Our study has showed that most participants inappropriately use and dispose of drugs, even though they know they can contaminate the environment

Antimicrobial susceptibility of enterobacteriaceae from street food sold in the vicinity of selected LRT-1 stations

Street food is one of the most sought-after inexpensive meal in the Philippines as it has become a fundamental source of sustenance for the general public. It is enjoyed by many because of its popular flavor, affordability, availability, and convenience. However, its reputation is preceded and stigmatized as unhealthy since bacterial contamination is often associated with it due to poor and improper handling and preparation practices. In the previous study of Baja and Salandanan (2017), a total of 71 Enterobacteriaceae isolates were collected from street food sold in the vicinity of selected LRT-1 stations (Doroteo Jose, Blumentrit, Monumento, and Balintawak). Out of 71 isolates, 49 were not identified and screened for antimicrobial sensitivity by Baja and Salandanan (2017), and therefore were utilized and tested in this study. However, only 48 were identified using biochemical tests as isolate S3C12 didn’t exhibit growth when retrieved from the stock culture. Biochemical test results showed that 35.4% (17 out of 48) were Enterobacter, 2.1% (1 out of 48) was Klebsiella, 2.1% (1 out of 48) was identified as Shigella while 60.4% (29 out of 48) of the isolates were not identified due to inconsistent and conflicting results. From the biochemical test results and colonial morphological identification, 26 representative isolates were subjected to antibiotic disc diffusion assay based on distinguishing characteristics. For the antibiotic disc-diffusion assay, 4 out of 26 (15%) isolates were considered multidrug resistant (MDR) after expressing resistance to more than three (3) antibiotics. Isolates which showed resistance to any of the Third Generation Cephalosporins (specifically ceftazidime) and any of the Carbapenems were subjected to confirmatory tests for Extended-Spectrum β-lactamase (ESBL) detection and Carbapenemase detection, respectively. For the confirmatory tests, 0 out of 2 (0%) isolates tested positive for ESBL production while 3 out of 4 (75%) isolates tested positive for the Carbapenamase productio

Water absorption by denture base resins

In a review of the international literature about water absorption of denture base resins any effect on the physical properties of these polymers has been considered. The authors discuss the possibilities of controlling the final results on denture base function