Field emission properties of carbon nanotube arrays grown in porous anodic alumina

AbstractCarbon nanotubes (CNTs), with their excellent electronic properties and extremely high aspect ratio, represent an ideal material for building electron sources based on field emission. Fowler‐Nordheim equation describes quite successfully the field emission phenomenon, especially for single or isolated tips. However, some complications arise when populations of CNTs are considered, where collective effects and large variability in the emitters features influence the measured I–V characteristics. In this work, the emission properties of multi‐walled CNTs grown within ordered anodic alumina templates are investigated. These CNT matrices produce current densities up to some tens of mA/cm2, and the field enhancement factor for collective emission sources can be estimated. Such material can be modelled as an ordered and uniform array of emitters and a simulation of the electrostatic field on the emission tips can be done in order to evaluate the field enhancement factor and its dependence on various geometries. This allows comparing predictions from simulation and experimental measurements, in a direct way. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim

Human papillomavirus 9-valent vaccine for cancer prevention: a systematic review of the available evidence.

In 2014, the Food and Drug Administration approved a new human papillomavirus 9-valent vaccine (9vHPV), targeting nine HPV types: HPV types 6, 11, 16, and 18, which are also targeted by the quadrivalent HPV vaccine (qHPV), plus five additional high cancer risk HPV types (HPV types 31, 33, 45, 52, and 58). The aim of the current study was to systematically retrieve, qualitatively and quantitatively pool, as well as critically appraise all available evidence on 9vHPV from randomized controlled trials (RCTs). We conducted a systematic review of the literature on 9vHPV efficacy, immunogenicity and safety, as well as a systematic search of registered, completed, and ongoing RCTs. We retrieved and screened 227 records for eligibility. A total of 10 publications reported on RCTs' results on 9vHPV and were included in the review. Sixteen RCTs on 9vHPV have been registered on RCT registries. There is evidence that 9vHPV generated a response to HPV types 6, 11, 16 and 18 that was non-inferior to qHPV. Vaccine efficacy against five additional HPV type-related diseases was directly assessed on females aged 16-26 years (risk reduction against high-grade cervical, vulvar or vaginal disease = 96·7%, 95% CI 80·9%-99·8%). Bridging efficacy was demonstrated for males and females aged 9-15 years and males aged 16-26 years (the lower bound of the 95% CIs of both the geometric mean titer ratio and difference in seroconversion rates meeting the criteria for non-inferiority for all HPV types). Overall, 9vHPV has been proved to be safe and well tolerated. Other RCTs addressed: 9vHPV co-administration with other vaccines, 9vHPV administration in subjects that previously received qHPV and 9vHPV efficacy in regimens containing fewer than three doses. The inclusion of additional HPV types in 9vHPV offers great potential to expand protection against HPV infection. However, the impact of 9vHPV on reducing the global burden of HPV-related disease will greatly depend on vaccine uptake, coverage, availability, and affordability

Non-syndromic sensorineural prelingual and postlingual hearing loss due to col11a1 gene mutation

This paper aims to present a third world case of Non-Syndromic sensorineural hearing loss (NSHL) due to a novel missense variant in COL11A1 gene, defined as DFNA37 non-syndromic hearing loss. The clinical features of a 6-year-old boy affected by a bilateral moderate to severe down-sloping sensorineural hearing loss are presented, as well as the genetic analysis, the latter identifying a heterozygous missense variation in the COL11A1 gene. In addition, in families with autosomal dominant transmission, COL11A1 gene should be considered in the genetic workup of the NSHL with prelingual onset

The evaluation of Vertigo in children: which role for parental-camera recording and telemedicine?

Sir, At this time, the management of pediatric patients affected by vertigo remains a challenge that requires a multidisciplinary approach and the collaboration of many specialists, such as otorhinolaryngologists, audiologists, pediatricians, and neurologists. Vertigo in children is a condition often difficult to assess since the little patients are frequently incapable to provide a complete description of their complaints, and parents can be inaccurate or incomplete, in describing or recognizing crucial clinical signs. Many disorders, including neurological and audio-vestibular diseases, can manifest with vertigo, which in children can occur alone or in association to other symptoms such as visual disturbances, migraine, or learning disabilities. It can severely affect the quality of life of both, children and their families, especially if persisting, enhancing parental concerns and anxieties. A careful collection of medical history, with a detailed description of symptoms, is crucial in the diagnostic process. However, parents/caregivers may omit important data since they are not trained to recognize red flags or specific signs. Thus, during the first consultation, otolaryngologists should alert parents/caregivers for assessing specific vertigo features, in the case of future episodes. Timing, frequency, triggers, and associated manifestations can be helpful details to report. Among specific diagnostic tools, the video Head Impulse Test (vHIT) is a valuable instrument for assessing the vestibular-ocular reflex (VOR), even if it can present a higher percentage of artefacts in children, mainly due to technical issues (i.e., higher gain and blinking eyes). Furthermore, while teenagers can undergo different investigations, including specific vestibular testing, the cooperation of younger children, for a full clinical and instrumental testing, can be tricky. Currently, the use of patients’ self-recorded videos is not common among the audio-vestibular practice. However, according to Gedik-Soyuyuce et al, their application can be valuable for observing children’s behaviors during acute vertigo attacks. Nowadays, smartphone high-definition cameras could be useful for recording the dizzy children during a crisis. Therefore, detailed features (i.e., eyes and body movements) could be documented, as already proposed for the adults affected by Meniere’s disease

Patent Foramen Ovale as Possible Cause of Sudden Sensorineural Hearing Loss: A Case Report

OBJECTIVE: To present a case of sudden sensorineural hearing loss (SSNHL) and the related diagnostic workup. CLINICAL PRESENTATION AND INTERVENTION: A 54-year-old man presented with a unilateral SSNHL episode and vertigo. A severe patent foramen ovale (PFO) that included a complete ear nose and throat, audiological, and neurological examination was discovered during the diagnostic workup. Audiometry, blood, and serological tests were performed. Magnetic resonance imaging and color Doppler echography of the supra-aortic trunks and lower limbs were carried out. Finally, transthoracic followed by transesophageal echocardiography and transcranial Doppler were performed in order to confirm the diagnosis of PFO. Medical therapy with systemic steroid and antiplatelet drugs was administered. CONCLUSIONS: This case showed a small PFO associated with an aneurysmatic interatrial septum. The PFO and paradoxical thromboembolism could be involved in the pathogenesis of SSNHL