Inflammatory Modifications in Paranasal Sinuses and Ostiomeatal Complex Anatomical Variations in Jet Aircraft Pilots: A Computed Tomography Study.

Introduction Jet aircraft pilots are exposed to huge pressure variation during flight, which affect physiological functions as systems, such as the respiratory system. Objectives The objective of the present investigation was to evaluate inflammatory changes of paranasal sinuses of jet aircraft pilots before and after a jet aircraft training program, using multislice computed tomography (CT), in comparison with a group of nonairborne individuals with the same age, sex, and physical health conditions. A second objective of the present study was to assess the association between the ostiomeatal complex obstruction and its anatomical variations. Methods The study group consisted of 15 jet aircraft pilots participating in the training program. The control group consisted of 41 nonairborne young adults. The 15 fighter pilots were evaluated before initiating the training program and after their final approval for the presence of inflammatory paranasal sinus disease. The ostiomeatal complex anatomical variations and obstructions were analyzed in pilots after the training program. Results Jet aircraft pilots presented higher incidence of mucosal thickening in maxillary sinus and anterior ethmoid cells than controls. Prominent ethmoidal bulla showed significant association with obstruction of the osteomeatal complex. Conclusions Jet aircraft pilots present increased inflammatory disease when compared with nonairborne individuals. The presence of a prominent ethmoidal bulla is associated with ostiomeatal complex obstruction.

Inflammatory Modifications in Paranasal Sinuses and Ostiomeatal Complex Anatomical Variations in Jet Aircraft Pilots: A Computed Tomography Study

Abstract Introduction Jet aircraft pilots are exposed to huge pressure variation during flight, which affect physiological functions as systems, such as the respiratory system. Objectives The objective of the present investigation was to evaluate inflammatory changes of paranasal sinuses of jet aircraft pilots before and after a jet aircraft training program, using multislice computed tomography (CT), in comparison with a group of nonairborne individuals with the same age, sex, and physical health conditions. A second objective of the present study was to assess the association between the ostiomeatal complex obstruction and its anatomical variations. Methods The study group consisted of 15 jet aircraft pilots participating in the training program. The control group consisted of 41 nonairborne young adults. The 15 fighter pilots were evaluated before initiating the training program and after their final approval for the presence of inflammatory paranasal sinus disease. The ostiomeatal complex anatomical variations and obstructions were analyzed in pilots after the training program. Results Jet aircraft pilots presented higher incidence of mucosal thickening in maxillary sinus and anterior ethmoid cells than controls. Prominent ethmoidal bulla showed significant association with obstruction of the osteomeatal complex. Conclusions Jet aircraft pilots present increased inflammatory disease when compared with nonairborne individuals. The presence of a prominent ethmoidal bulla is associated with ostiomeatal complex obstruction.

Maxillary sinus volumetric changes in jet aircraft pilots: A multislice computed tomography pilot study.

Purpose: This study evaluated maxillary sinus volume changes in military jet aircraft pilot candidates before and after the training program, in comparison with a control group, considering the effects of pressurization, altitude, and total flight hours, through multislice computed tomography. Materials and Methods: Fifteen fighter pilots were evaluated before initiating the training program and after the final approval. The control group consisted of 41 young adults who had not flown during their military career. The volumes of each maxillary sinus were measured individually before and at the end of the training program. Results: When comparing the initial and final volumes in the pilots, a statistically significant increase was observed both in the left and right maxillary sinuses. When evaluating the average total volume of the maxillary sinuses (i.e., the average volume of the right and left maxillary sinuses together), a significant increase in the volume of the maxillary sinuses was observed in the pilot group when compared to the control group. Conclusion: The maxillary sinus volumes in aircraft pilot candidates increased after the 8-month training program. This may be explained by changes in the gravitational force, the expansion of gas, and positive pressure from oxygen masks. This unprecedented investigation among pilots might lead to other investigations considering paranasal sinus alterations in this singular population.

A chemisorbed interfacial layer for seeding atomic layer deposition on graphite.

The integration of graphene, and more broadly two-dimensional materials, into devices and hybrid materials often requires the deposition of thin films on their usually inert surface. As a result, strategies for the introduction of surface reactive sites have been developed but currently pose a dilemma between robustness and preservation of the graphene properties. A method is reported here for covalently modifying graphitic surfaces, introducing functional groups that act as reactive sites for the growth of high quality dielectric layers. Aryl diazonium species containing tri-methoxy groups are covalently bonded (grafted) to highly oriented pyrolytic graphite (HOPG) and graphene, acting as seeding species for atomic layer deposition (ALD) of Al2O3, a high-κ dielectric material. A smooth and uniform dielectric film growth is confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrical measurements. Raman spectroscopy showed that the aryl groups gradually detach from the graphitic surface during the Al2O3 ALD process at 150 °C, with the surface reverting back to the original sp2-hybridized state and without damaging the dielectric layer. Thus, the grafted aryl groups can act as a sacrificial seeding layer after healing the defects of the graphitic surface with annealing treatment.

Photo-induced electrodeposition of metallic nanostructures on graphene.

Graphene, a single atomic layer of sp2 hybridized carbon, is a promising material for future devices due to its excellent optical and electrical properties. Nevertheless, for practical applications, it is essential to deposit patterned metals on graphene in the micro and nano-meter scale in order to inject electrodes or modify the 2D film electrical properties. However, conventional methods for depositing patterned metals such as lift-off or etching leave behind contamination. This contamination has been demonstrated to deteriorate the interesting properties of graphene such as its carrier mobility. Therefore, to fully exploit the unique properties of graphene, the controlled and nano-patterned deposition of metals on graphene films without the use of a sacrificial resist is of significant importance for graphene film functionalization and contact deposition. In this work, we demonstrate a practical and low-cost optical technique of direct deposition of metal nano-patterned structures without the need for a sacrificial lift-off resist. The technique relies on the laser induced reduction of metal ions on a graphene film. We demonstrate that this deposition is optically driven, and the resolution is limited only by the diffraction limit of the light source being used. Patterned metal features as small as 270 nm in diameter are deposited using light with a wavelength of 532 nm and a numerical aperture of 1.25. Deposition of different metals such as Au, Ag, Pd, Pb and Pt is shown. Additionally, change in the Fermi level of the graphene film through the nano-patterned metal is demonstrated through the electrical characterization of four probe field effect transistors.

Choroidal Melanoma Metastatic to the Contralateral Medial Rectus After Orbital Exenteration

A 78-year-old Caucasian woman presented with pain in her right and only eye that was worse on abduction. Her history was significant for a choroidal melanoma affecting her left eye for which she underwent an orbital exenteration 12 years previously. Computed tomography and magnetic resonance imaging of the right orbit identified a mass lesion affecting the medial rectus, suspicious for metastatic melanoma. A histopathological diagnosis of metastatic melanoma was subsequently made following biopsy of the right medial rectus.

Oncocytic cyst of the larynx: a rare finding.

A 75-year-old woman presented with an 18-month history of severe, slowly worsening dysphonia. She was a smoker and known to have multiple benign cystic thyroid lesions. She reported no associated symptoms and other medical and social history was unremarkable. Fibreoptic nasendoscopy revealed a right-sided supraglottic cyst appearing to arise from the right false vocal cord. Further bedside examination was unremarkable. She underwent microlaryngoscopy and biopsy which showed a cyst originating from the right anterior ventricle, successfully removed without rupture using cold steel. Formal histopathology revealed a 14×10×7 mm unilocular, completely excised cyst lined by oncocytic epithelium and composed of columnar cells with darkly stained nuclei and abundant granular, eosinophilic cytoplasm. Three weeks postoperatively the patient's voice had returned to normal. To date, 11 months postoperatively, there is no evidence of recurrence, and she will continue long-term follow-up.

Orbital tuberculosis: perspectives from Victoria, Australia.

PURPOSE: Orbital tuberculosis (TB) is a rare extra-pulmonary manifestation of tuberculosis and its clinical diagnosis poses unique challenges, with potential for destructive complications as well as social and public health implications. The aim of this study is to report our experience of patients presenting with orbital TB and to identify common aspects. METHODS: A systematic search for mandatory notifications of orbital tuberculosis between January 01, 1994 and December 12, 2016 was undertaken in the Victorian Tuberculosis database. In addition, members of the Australian and New Zealand Society of Ophthalmic Plastic Surgeons (ANZSOPS) were surveyed to identify cases of orbital tuberculosis diagnosed on biopsy in the past 20 years. Medical case notes of identified cases were reviewed retrospectively. RESULTS: Three cases were identified as having occurred in Victoria, aged 44-59 years old. All cases had emigrated from endemic countries with higher tuberculosis burden. Diagnosis of tuberculosis was often difficult due to few or non-viable acid fast bacilli and low yield of positive culture in paucicellular orbital specimens. CONCLUSIONS: Orbital TB is rare but remains an important differential diagnosis of orbital mass lesions. The diagnosis of orbital TB requires a high index of clinical suspicion and targeted investigations in patients originating from endemic areas. Diagnosis and treatment rely on effective collaboration between ophthalmologists, infectious disease physicians, and pathologists.

From the metal to the channel: a study of carrier injection through the metal/2D MoS2 interface.

Despite the fact that two-dimensional MoS2 films continue to be of interest for novel device concepts and beyond silicon technologies, there is still a lack of understanding on the carrier injection at metal/MoS2 interface and effective mitigation of the contact resistance. In this work, we develop a semi-classical model to identify the main mechanisms and trajectories for carrier injection at MoS2 contacts. The proposed model successfully captures the experimentally observed contact behavior and the overall electrical behavior of MoS2 field effect transistors. Using this model, we evaluate the injection trajectories for different MoS2 thicknesses and bias conditions. We find for multilayer (>2) MoS2, the contribution of injection at the contact edge and injection under the contact increase with lateral and perpendicular fields, respectively. Furthermore, we identify that the carriers are predominantly injected at the edge of the contact metal for monolayer and bilayer MoS2. Following these insights, we have found that the transmission line model could significantly overestimate the transfer length and hence the contact resistivity for monolayer and bilayer MoS2. Finally, we evaluate different contact strategies to improve the contact resistance considering the limiting injection trajectory.

CHORIORETINAL BIOPSY FOR THE DIAGNOSIS OF ENDOGENOUS ENDOPHTHALMITIS DUE TO ESCHERICHIA COLI.

PURPOSE: To describe the novel use of a chorioretinal biopsy technique to confirm the microbiological diagnosis of endogenous Escherichia coli (E. coli) endophthalmitis, when other investigations have been proven nondiagnostic. METHODS: Case report of an 82-year-old white man with endogenous endophthalmitis without a clearly identifiable source of infection. RESULTS: After systemic cultures and multiple aqueous and vitreous samples were unable to identify a causative organism, chorioretinal biopsy of a subretinal abscess was used to confirm the microbiological diagnosis. This ensured appropriate ophthalmic and systemic treatment of infection. CONCLUSION: Endogenous E. coli endophthalmitis is a rare and aggressive condition usually seen in patients with insulin-dependent diabetes with concurrent urinary tract infection. This case demonstrates chorioretinal biopsy to be a viable and effective method of establishing a firm microbiological diagnosis in cases of culture-negative endophthalmitis.

Highly efficient and stable MoS2 FETs with reversible n-doping using a dehydrated poly(vinyl-alcohol) coating.

Despite rapid progress in 2D molybdenum disulfide (MoS2) research in recent years, MoS2 field-effect transistors (FETs) still suffer from a high metal-to-MoS2 contact resistance and low intrinsic mobility, which are major hindrances to their future application. We report an efficient technique to dope thin-film MoS2 FETs using a poly(vinyl-alcohol) (PVA) polymeric coating. This results in a reduction of the contact resistance by up to 30% as well as a reduction in the channel resistance to 20 kΩ sq-1. Using a dehydration process, we were able to effectively control the surface interactions between MoS2 and the more electropositive hydroxyl groups (-OH) of PVA, which provided a controllable and yet reversible increase in the charge carrier density to a value of 8.0 × 1012 cm-2. The non-covalent, thus non-destructive, PVA doping of MoS2 increases the carrier concentration without degrading the mobility, which shows a monotonic increase while enhancing the doping effect. The PVA doping technique is then exploited to create heavily doped access regions to the intrinsic MoS2 channel, which yields 200% increase of the ON-state source-drain current. This establishes PVA doping as an effective approach to enhance the transport properties of MoS2 FETs for a variety of applications.

Malignant Transformation of Optic Nerve Melanocytoma into Melanoma Associated with Ocular Ischemic Syndrome and Oculocardiac Reflex: Case Report and Review of the Literature.

PURPOSE: To describe the clinical and pathological features of malignant transformation of an optic nerve melanocytoma over 25 years, associated with spontaneous extensive tumor necrosis, neovascular glaucoma, ocular ischemic syndrome, and oculocardiac reflex. PROCEDURES: A 60-year-old Caucasian female presented with acute severe left ocular pain and glaucoma with an intraocular pressure of 80 mmHg and bradycardia (28-40 beats/min). RESULTS: Histopathological examination of the enucleated eye showed features of malignant transformation of a spontaneously necrotic optic nerve melanocytoma associated with ocular ischemic syndrome and neovascular glaucoma. CONCLUSIONS: Yearly follow-up and awareness of possible but well-documented malignant transformation, even over several decades, is recommended. This case presents malignant transformation of an optic nerve melanocytoma associated with the common complications described in the literature over the years. Of particular interest was the development of oculocardiac reflex in this patient.

Novel CT-guided biopsy of isolated perineural spread of adenoid cystic carcinoma along the trigeminal nerve masquerading as chronic trigeminal neuropathy.

The differential diagnoses for chronic peripheral neuropathy are broad and diagnosing a cause can be challenging. We present a case of isolated perineural spread of adenoid cystic carcinoma to the trigeminal nerve involving skull base foramina and Meckel's cave in the setting of chronic trigeminal neuropathy and no known prior malignancy. Computed tomography-guided core (CT) needle biopsy was needed to arrive at a diagnosis and a novel approach was required to obtain tissue from the trigeminal nerve lesion at foramen ovale.

Tunable doping of graphene by using physisorbed self-assembled networks.

One current key challenge in graphene research is to tune its charge carrier concentration, i.e., p- and n-type doping of graphene. An attractive approach in this respect is offered by controlled doping via well-ordered self-assembled networks physisorbed on the graphene surface. We report on tunable n-type doping of graphene using self-assembled networks of alkyl-amines that have varying chain lengths. The doping magnitude is modulated by controlling the density of the strong n-type doping amine groups on the surface. As revealed by scanning tunneling and atomic force microscopy, this density is governed by the length of the alkyl chain which acts as a spacer within the self-assembled network. The modulation of the doping magnitude depending on the chain length was demonstrated using Raman spectroscopy and electrical measurements on graphene field effect devices. This supramolecular functionalization approach offers new possibilities for controlling the properties of graphene and other two-dimensional materials at the nanoscale.

Spinal metallosis: a systematic review.

PURPOSE: To document a rarely reported complication associated with spinal instrumentation and to evaluate the current literature on spinal metallosis and spinal metalloma. METHODS: A local case report is presented. EBSCOhost, PubMed and ScienceDirect databases were used to conduct a systematic review for articles describing spinal metallosis and spinal metalloma. RESULTS: A total of 836 articles were identified using the terms "metalloma" or "metallosis". Exclusion of arthroplasty-related abstracts retrieved 46 articles of which 3 full text articles presenting spinal metalloma as a causative pathological finding responsible for neurological signs and symptoms in patients with previous spinal fusion instrumentation were reviewed. Our case is the first described with titanium-composed posterior instrumentation and fifth reported, demonstrating the phenomena of neurological symptoms and signs attributed directly to neural tissue compression by spinal metalloma after spinal instrumentation. CONCLUSION: Spinal metallosis can present weeks to years after spinal instrumentation surgery and is a potential cause of neural compression. This process appears to be independent of the instrument composition as metallosis has now been demonstrated in both titanium and stainless steel constructs.

Orbital Paraganglioma and Succinate Dehydrogenase Staining for Genetic Testing Triage and Prognosis.

PURPOSE OF THE STUDY: To describe the rare occurrence of a paraganglioma in the orbit and how to triage for genetic testing and assess the prognosis with succinate dehydrogenase subunit B (SDHB) immunohistochemical staining. METHOD: Case report. PROCEDURES: A 47-year-old 'healthy' male presented with painless exophthalmos and diplopia secondary to an infraorbital tumour mass. RESULTS: The orbital biopsy was diagnosed as paraganglioma with positive staining with SDHB. CONCLUSION: The rarity of an orbital paraganglioma was followed by the clinical search for a possible occult extraorbital primary paraganglioma. SDHB staining helped in the triage for genetic testing and gave an idea about the prognosis for this tumour.

Safety and efficacy of explanting or replacing suprachoroidal electrode arrays in a feline model.

BACKGROUND: A key requirement for retinal prostheses is the ability for safe removal or replacement. We examined whether suprachoroidal electrode arrays can be removed or replaced after implantation. METHODS: Suprachoroidal electrode arrays were unilaterally implanted into 13 adult felines. After 1 month, arrays were surgically explanted (n = 6), replaced (n = 5) or undisturbed (n = 2). The retina was assessed periodically using fundus photography and optical coherence tomography. Three months after the initial implantation, the function of replaced or undisturbed arrays was assessed by measuring the responses of the visual cortex to retinal electrical stimulation. The histopathology of tissues surrounding the implant was examined. RESULTS: Array explantation or replacement was successful in all cases. Fundus photography showed localized disruption to the tapetum lucidum near the implant's tip in seven subjects following implantation. Although optical coherence tomography showed localized retinal changes, there were no widespread statistically significant differences in the thickness of the retinal layers or choroid. The distance between the electrodes and retina increased after device replacement but returned to control values within eight weeks (P < 0.03). Staphylomas developed near the scleral wound in five animals after device explantation. Device replacement did not alter the cortical evoked potential threshold. Histopathology showed localized outer nuclear layer thinning, tapetal disruption and pseudo-rosette formation, but the overall retinal morphology was preserved. CONCLUSIONS: It is feasible to remove or replace conformable medical grade silicone electrode arrays implanted suprachoroidally. The scleral wound requires careful closure to minimize the risk of staphylomas.

Temporal and pharmacological characterization of angiostatin release and generation by human platelets: implications for endothelial cell migration.

Platelets play an important role in thrombosis and in neo-vascularisation as they release and produce factors that both promote and suppress angiogenesis. Amongst these factors is the angiogenesis inhibitor angiostatin, which is released during thrombus formation. The impact of anti-thrombotic agents and the kinetics of platelet angiostatin release are unknown. Hence, our objectives were to characterize platelet angiostatin release temporally and pharmacologically and to determine how angiostatin release influences endothelial cell migration, an early stage of angiogenesis. We hypothesized anti-platelet agents would suppress angiostatin release but not generation by platelets. Human platelets were aggregated and temporal angiostatin release was compared to vascular endothelial growth factor (VEGF). Immuno-gold electron microscopy and immunofluorescence microscopy identified α-granules as storage organelles of platelet angiostatin. Acetylsalicylic acid, MRS2395, GPIIb/IIIa blocking peptide, and aprotinin were used to characterize platelet angiostatin release and generation. An endothelial cell migration assay was performed under hypoxic conditions to determine the effects of pharmacological platelet and angiostatin inhibition. Compared to VEGF, angiostatin generation and release from α-granules occurred later temporally during platelet aggregation. Consequently, collagen-activated platelet releasates stimulated endothelial cell migration more potently than maximally-aggregated platelets. Platelet inhibitors prostacyclin, S-nitroso-glutathione, acetylsalicylic acid, and GPIIb/IIIa blocking peptide, but not a P2Y12 inhibitor, suppressed angiostatin release but not generation. Suppression of angiostatin generation in the presence of acetylsalicylic acid enhanced platelet-stimulated endothelial migration. Hence, the temporal and pharmacological modulation of platelet angiostatin release may have significant consequences for neo-vascularization following thrombus formation.