Disc Antenna Enhanced Infrared Spectroscopy: From Self-Assembled Monolayers to Membrane Proteins.

Plasmonic surfaces have emerged as a powerful platform for biomolecular sensing applications and can be designed to optimize the plasmonic resonance for probing molecular vibrations at utmost sensitivity. Here, we present a facile procedure to generate metallic microdisc antenna arrays that are employed in surface-enhanced infrared absorption (SEIRA) spectroscopy of biomolecules. Transmission electron microscopy (TEM) grids are used as shadow mask deployed during physical vapor deposition of gold. The resulting disc-shaped antennas exhibit enhancement factors of the vibrational bands of 4 × 104 giving rise to a detection limit <1 femtomol (10-15 mol) of molecules. Surface-bound monolayers of 4-mercaptobenzoic acid show polyelectrolyte behavior when titrated with cations in the aqueous medium. Conformational rigidity of the self-assembled monolayer is validated by density functional theory calculations. The membrane protein sensory rhodopsin II is tethered to the disc antenna arrays and is fully functional as inferred from the light-induced SEIRA difference spectra. As an advance to previous studies, the accessible frequency range is improved and extended into the fingerprint region.

Characterization of Thermal Oxides on 4H-SiC Epitaxial Substrates Using Fourier-Transform Infrared Spectroscopy.

Fourier transform infrared (FT-IR) spectra were measured for thermal oxides with different electrical properties grown on 4H-SiC substrates. The peak frequency of the transverse optical (TO) phonon mode was blue-shifted by 5 cm-1 as the oxide-layer thickness decreased to 3 nm. The blue shift of the TO mode indicates interfacial compressive stress in the oxide. Comparison of data for the oxide on a SiC substrate with that for similar oxides on a Si substrate implies that the peak shift of the TO mode at the SiO2/SiC interface is larger than that of SiO2/Si, which suggests that the interfacial stress for the oxide on the SiC substrate is larger than that on the Si substrate. For the SiO2/SiC interfacial region (<3 nm oxide thickness), despite the fact that the blue shift of the TO modes becomes larger while approaching the oxide/SiC interface, the peak frequency of the TO modes red-shifts at the oxide/SiC interface. The peak-frequency shift of the TO mode for the sample without post-oxidation annealing was larger than that for the samples post-annealed in a nitric oxide atmosphere. The channel mobilities are correlated with the degree of shift of the TO mode when the oxide thickness is <3 nm. It appears that the compressive stress at the SiO2/SiC interface generates silicon suboxide components and weakens the Si-O bonds. As the result, the TO mode was red-shifted and the oxygen deficiency increased to relax the compressive stress in the oxide with <3 nm thickness. Fourier transform infrared spectroscopy measurements provide unique and useful information about stress and inhomogeneity at the oxide/SiC interface.

Occurrence of cardiovascular events after the 2011 Great East Japan Earthquake and tsunami disaster.

There are conflicting reports regarding the occurrence of cardiovascular events after a major earthquake. To understand the impact of the Great East Japan Earthquake on cardiovascular events, we retrospectively examined the clinical records prepared by emergency room physicians between 2009 and 2011 (n = 66,244), and compared the occurrence of these events between 2011 and 2009, and 2011 and 2010. There was a significant increase in the number of patients with cardiovascular events during the 3 week period after the earthquake in 2011 (n = 106) compared with that during the same period in 2009 (n = 72) or 2010 (n = 65) (P = 0.002). The number of patients with acute coronary syndrome or congestive heart failure in March 2011 was significantly increased compared with 2009 or 2010, however, there were no significant increases in 2011 in other cardiovascular events including stroke, aortic dissection, pulmonary thromboembolism, or out-of-hospital cardiac arrest compared with 2009 or 2010. These findings suggest that the incidence of cardiovascular events may have been heterogeneous after the disaster.

Comparison of large intrasylvian and subpial hematomas caused by rupture of middle cerebral artery aneurysm.

The clinical characteristics of intrasylvian and subpial hematomas caused by rupture of middle cerebral artery (MCA) aneurysm were examined in 86 patients admitted to our department with subarachnoid hemorrhage (SAH) caused by ruptured MCA aneurysms. A retrospective study of 26 patients with a large hematoma associated with SAH treated surgically within 48 hours evaluated clinical grade at admission, secondary development of cerebral swelling, ratio of hematoma removal, and incidence of symptomatic vasospasm. Clinical grade on admission, age, and sex showed no significant differences. Ratio of cerebral swelling against the initial hematoma volume (p = 0.005), and incidence of symptomatic vasospasm (p = 0.041) were significantly lower, and the ratio of hematoma was significantly higher (p = 0.01) in the subpial hematoma group. Removal of hematoma was more difficult and symptomatic vasospasm was more frequent in the intrasylvian hematoma group. The clinical features of subpial and intrasylvian hematomas caused by rupture of MCA aneurysm should be considered for the better management of associated SAH.

Evolution of vestibular schwannoma after removal of epidermoid cyst of the same location: case report.

A 71-year-old man presented with vestibular schwannoma manifesting as hearing disturbance and truncal ataxia 16 years after removal of a cerebellopontine angle (CPA) epidermoid cyst, and located adjacent to the remnant lesion. The patient first presented with a 6-month history of right trigeminal neuralgia. Neuroimaging demonstrated a right CPA lesion, suggestive of an epidermoid cyst. Right lateral suboccipital craniotomy was performed and the histological diagnosis was epidermoid cyst. A small lesion remained, but the symptoms were relieved. Sixteen years later, the patient presented with right auditory disturbance, vertigo, and truncal ataxia. Magnetic resonance imaging revealed a multiple cystic mass adjacent to the remnant epidermoid cyst in the right CPA. The lesion was removed and the histological diagnosis was vestibular schwannoma associated with the epidermoid cyst. The irritative effect of the remnant epidermoid cyst or surgical procedures may have caused the vestibular schwannoma, but no evidence of the evolution of the different types of tumors was found.

Adult traumatic leptomeningeal cyst: case report.

A 60-year-old man presented with a traumatic leptomeningeal cyst manifesting as local tenderness in the right parietal region and local headache 2 years after head injury. Magnetic resonance imaging showed a small arachnoid cyst under bone defect. Dural and bone plasty were performed. Intraoperative examination found small and round defects of the dura and bone. Progressive headache was relieved after the surgery. This rare case of adult posttraumatic leptomeningeal cyst occurred within an unusually short period after trauma, and was associated with a small and round bone defect and small dural defect usually characteristic of congenital arachnoid cyst.

Ruptured pseudoaneurysm following Gamma Knife surgery for a vestibular schwannoma.

A 75-year-old woman underwent Gamma Knife surgery (GKS) for a vestibular schwannoma. Eight years after GKS, she suffered sudden onset of headache. Computed tomography revealed diffuse subarachnoid hemorrhage around the cisterns of the posterior fossa. Right vertebral artery angiography showed an aneurysm arising from the lateral pontomedullary segment of the left anterior inferior cerebellar artery. The aneurysm was not located at a branching site. Trapping of the distal anterior inferior cerebellar artery aneurysm was performed, and the aneurysm was removed. The pathological features of this aneurysm are discussed. This aneurysm was diagnosed as a pseudoaneurysm pathologically. This is the first report of aneurysm formation with pathological findings following GKS for a vestibular schwannoma.

A case of multiple pial arteriovenous fistulas associated with dural arteriovenous fistula.

Pial arteriovenous fistulas (AVFs) are known as rare cerebrovascular lesions. They are composed of >/= 1 arterial feeding vessels and a single draining vein that usually has high perfusion pressure and generally occur in infants. Cases involving adults are very rare and the developmental mechanisms and natural history of these lesions remain unknown. The authors present a case of multiple pial AVFs in an adult in whom the lesions developed after radiosurgical treatment of dural AVFs. Direct disconnection of pial arterial supplies was performed, and the abnormal shunts were successfully eliminated. The authors report the clinical course of this case and discuss the characteristics of and treatment strategy for multiple pial AVFs, reviewing the published literature.