Optimization of the chin bar of a composite-shell helmet to mitigate the upper neck force

The chin bar of motorcycl e full - face helmets is the most likely region of the helmet to sustain impact s during accident s , with a large percentage of these impacts lead ing to basilar skull fracture . Currently, helmet chin bars are designed to mitigate the peak acceleration at the c entre o f g ravity of isolated headforms , as required by standards, but they are not designed to mitigate the neck force, which is probably the cau se of basilar skull fracture, a type of head injury that can lead to fatalities . Here we test whether it is possible to increase the protection of helmet chin bars while meeting standard requirements. Fibre - reinforced composite shells are commonly used in helmets due to their lightweight and energy absorption charac teristics. W e optimize the ply orientation of a chin bar made of fibre - reinforced composite layers for reduction of the neck force in a dummy model using a computational approach . We use the fini te element model of a human head/neck surrogate and measure the neck axial force, which has been shown to be correlated with the risk of basilar skull fracture. The results show t hat by varying the orientation of the chin bar plies , thus keeping the helmet mass constant, the neck axial force can be reduced by approximately 3 0 % while ensuring that the helmet complies with the impact attenuation requirements prescribed in helmet standards

A Simple Three-component Synthesis of 3-Amino-5-arylpyridazine-4-carbonitriles

New 3-amino-5-arylpyridazine-4-carbonitriles have been synthesized by a one-pot three-component reaction of malononitrile with arylglyoxals in the presence of hydrazine hydrate at room temperature in water and ethanol.KEYWORDS Arylglyoxals, arylpyridazines, hydrazine hydrate, one-pot, malononitrile

The Prevalence of Restless Legs Syndrome in Patients Undergoing Hemodialysis: A Systematic Review and Meta-analysis Study

Introduction: Restless legs syndrome is a sensory-motor disorder that causes sleep disorder. The syndrome in patients undergoing hemodialysis associates with depression, sleep deprivation, performance disorder, day fatigue, excessive daytime sleepiness, stress, anxiety, and higher risk of cardiovascular diseases. The objective of this systematic meta-analysis study was to estimate prevalence of restless legs syndrome in patients undergoing hemodialysis. Methods: Twenty-six relevant articles published between 2000 and 2015 indexed in Iranian (MagIran and IranMedex) and international databases (SID, Google Scholar, ScienceDirect, PubMed, Pre Quest, and Scopus) were selected. Data analysis was carried out through metaanalysis (random effect model) and heterogeneity of the studies was determined using I2 index. The obtained data were analyzed in STAT (11.2). Results: Prevalence of the syndrome according to the found articles was 50 (95 CI: 38-61) in Iranian and 30 (95 CI: 23-37) in international databases. There was an ascending trend of prevalence of the syndrome corresponding to the publication year of the articles (P= 0.419), while the trend based on age of the patients was descending (P= 0.604). However, the variations were not significant. Conclusion: Given the high prevalence and considerable effects of restless legs syndrome on patients undergoing hemodialysis, it is recommended that these patients be screened for the syndrome

The Association Between Obstructive Sleep Apnea and Depression in Older Adults

Background: Depression is the most frequent psychiatric disorder among the elderly. Obstructive sleep apnea (OSA) is a chronic and prevalent disease that has an ambiguous role in triggering depression. Several researches with contradictory findings have been performed about the association between OSA and depression. Objectives: This study aimed to investigate the association between OSA and depression among elderly. Patients and Methods: A total of 350 home residing elderly took part in this case-control study. The participants were selected using clustering method. All cases were divided into two groups of depressed and non-depressed using the geriatric depression scale (GDS). Then they were matched in age, gender, education and body mass index (BMI). Berlin questionnaire (BQ) was used to diagnose OSA. Data analysis was performed using Mann-Whitney U test, t-test, Chi-square and Fisher’s exact tests and odds ratio. Results: Totally, 60.6 % of depressed group and 18.9 % of non-depressed group were in high risk for OSA. A significant association was found between OSA and depression (P < 0.001, OR = 6.61, CI 95 % = 4.1 - 10.7). In addition, a significant association was found between gender and OSA (P = 0.008). Conclusions: OSA was associated with depression among the elderly patients. Given the high prevalence of OSA in older adults, implementation of screening methods is necessary to identify people at high risk of OSA

Relationship between Obstructive Sleep Apnea (OSA) and Difficult Intubation

BACKGROUND AND OBJECTIVE: One of the challenges of patients who are candidates for anesthesia is difficult intubation, which leads to severe complications and even death after anesthesia. The aim of this study is to investigate the relationship between obstructive sleep apnea and difficult intubation through systematic review and meta-analysis. METHODS: In this review article, observational articles about the relationship between obstructive sleep apnea and difficult intubation were extracted without time limit by searching national and international databases and the keywords were: difficult intubation, problematic intubation, Intra tracheal-endotracheal, difficult airway OSA, OSAS, obstructive sleep apnea, sleep breathing disorder, anesthesia, and their Persian equivalents. Data were analyzed using meta-analysis and fixed effects model. In order to study the heterogeneity and contradictions in the studies, Q Cochrane and I2 indices were used, respectively. FINDINGS: Of the 72 found articles, 9 articles with a sample size of 1,126 and an average of 125 subjects were included in the study. The results of this study showed that the relationship between obstructive sleep apnea and difficult intubation is significant (OR = 3.88, CI95% = 2.69 – 5.61). In addition, the results of the analysis based on country showed that the highest and lowest odds ratios were observed in studies conducted in France and Canada, respectively. CONCLUSION: The results of this study showed that there is a correlation between obstructive sleep apnea and difficult intubation

A multimodal deep learning framework using local feature representations for face recognition

YesThe most recent face recognition systems are mainly dependent on feature representations obtained using either local handcrafted-descriptors, such as local binary patterns (LBP), or use a deep learning approach, such as deep belief network (DBN). However, the former usually suffers from the wide variations in face images, while the latter usually discards the local facial features, which are proven to be important for face recognition. In this paper, a novel framework based on merging the advantages of the local handcrafted feature descriptors with the DBN is proposed to address the face recognition problem in unconstrained conditions. Firstly, a novel multimodal local feature extraction approach based on merging the advantages of the Curvelet transform with Fractal dimension is proposed and termed the Curvelet–Fractal approach. The main motivation of this approach is that theCurvelet transform, a newanisotropic and multidirectional transform, can efficiently represent themain structure of the face (e.g., edges and curves), while the Fractal dimension is one of the most powerful texture descriptors for face images. Secondly, a novel framework is proposed, termed the multimodal deep face recognition (MDFR)framework, to add feature representations by training aDBNon top of the local feature representations instead of the pixel intensity representations. We demonstrate that representations acquired by the proposed MDFR framework are complementary to those acquired by the Curvelet–Fractal approach. Finally, the performance of the proposed approaches has been evaluated by conducting a number of extensive experiments on four large-scale face datasets: the SDUMLA-HMT, FERET, CAS-PEAL-R1, and LFW databases. The results obtained from the proposed approaches outperform other state-of-the-art of approaches (e.g., LBP, DBN, WPCA) by achieving new state-of-the-art results on all the employed datasets

Role of Innate Immunity in the Pathogenesis of Chronic Rhinosinusitis: Progress and New Avenues

Chronic rhinosinusitis is a heterogeneous and multifactorial disease with unknown etiology. Aberrant responses to microorganisms have been suggested to play a role in the pathophysiology of the disease. Research has focused on the presence, detection, response to, and eradication of these potential threats. Main topics seem to center on the contribution of structural cells such as epithelium and fibroblasts, on the consequences of activation of pattern-recognition receptors, and on the role of antimicrobial agents. This research should be viewed not only in the light of a comparison between healthy and diseased individuals, but also in a comparison between patients who do or do not respond to treatment. New players that could play a role in the pathophysiology seem to surface at regular intervals, adding to our understanding (and the complexity) of the disease and opening new avenues that may help fight this incapacitating disease