Revisit of the plasmon-mediated chemical transformation of para-aminothiophenol.

Fingerprint Raman features of para-aminothiophenol (pATP) in surface-enhanced Raman scattering (SERS) spectra have been widely used to measure plasmon-driven catalytic activities because the appearance of characteristic spectral features is purported to be due to plasmon-induced chemical transformation of pATP to trans-p,p'-dimercaptoazobenzene (trans-DMAB). Here, we present a thorough comparison of SERS spectra for pATP and trans-DMAB in the extended range of frequencies covering group vibrations, skeletal vibrations, and external vibrations under various conditions. Although the fingerprint vibration modes of pATP could be almost mistaken with those of trans-DMAB, the low-frequency vibrations revealed distinct differences between pATP and DMAB. Photo-induced spectral changes of pATP in the fingerprint region were explained well by photo-thermal variation of the Au-S bond configuration, which affects the degree of the metal-to-molecule charge transfer resonance. This finding indicates that a large number of reports in the field of plasmon-mediated photochemistry must be reconsidered.

Density and viscosity of liquid ZrO2 measured by aerodynamic levitation technique.

Liquid ZrO2 is one of the most important materials involved in severe accident analysis of a light-water reactor. Despite its importance, the physical properties of liquid ZrO2 are scarcely reported. In particular, there are no experimental reports on the viscosity of liquid ZrO2. This is mainly due to the technical difficulties involved in the measurement of thermo-physical properties of liquid ZrO2, which has an extremely high melting point. To address this problem, an aerodynamic levitation technique was used in this study. The density of liquid ZrO2 was calculated from its mass and volume, estimated based on the recorded image of the sample. The viscosity was measured by a droplet oscillation technique. The density and viscosity of liquid ZrO2 at temperatures ranging from 2753 K to 3273 K, and 3170 K-3471 K, respectively, were successfully evaluated. The density of liquid ZrO2 was found to be 4.7 g/cm 3 at its melting point of 2988 K and decreased linearly with increasing temperature, and the viscosity of liquid ZrO2 was 13 mPa at its melting point.

Malignant lymphoma arising in the cerebral parenchyma adjacent to a parasagittal meningioma.

A 70-year-old woman with an asymptomatic parasagittal meningioma had been under observation with follow-up imaging for 2 years. She gradually developed motor weakness in the left hand. Magnetic resonance (MR) imaging disclosed a newly developed well-enhanced area in the cerebral parenchyma adjacent to the stable original meningioma. The new lesion was enhanced more intensely and less well demarcated. We suspected that the meningioma had enlarged into the brain parenchyma, although MR imaging suggested a border between the extra-axial and intra-axial portions. Craniotomy was performed. Two separate tumors were identified with quite different histological features. The extra-axial tumor was identified as benign transitional meningioma and the intra-axial tumor as diffuse large cell type malignant lymphoma. Immunostaining revealed the lymphoma had B cell origin. After surgical resection, stereotactic radiosurgery was performed for the residual lymphoma. The original site of the lymphoma remained free from relapse, but another lesion developed in the right frontal lobe 3 months later and chemotherapy was performed. The main concern for follow-up imaging of asymptomatic meningioma without surgical resection is growth of the meningioma. However, development of new different tumors is possible, although thought to be rare.

[A case of spontaneous intracranial hypotension effectively treated with cervical epidural blood patch].

We report a case of cervical spontaneous intracranial hypotension (SIH). The patient is a 46-year-old woman with hard of hearing, dizziness and postural headache. Radionuclide cisternography (RNC) demonstrated a cerebrospinal fluid (CSF) leak at the low cervical region. Resolution of headache was obtained by conservative therapies of bed rest and intravenous (i.v.) drip infusion, but the dizziness remained. We performed epidural blood patch (EBP) with 8 ml of autologous blood at the C 6-7 interspace. Her dizziness disappeared after several days of EBP. SIH is an uncommon disease caused by CSF leakage. SIH is often self-limiting, responding to bed rest and/or i.v. drip infusion. However, if the symptoms of SIH do not show a complete recovery by conservative therapies, EBP or continuous epidural infusion of saline has reportedly been used for the management of these cases. Most of the reported cases of EBP are in the thoracic and lumbar spinal regions. We have performed cervical EBP without complications, and the 6 month-follow-up MRI and RNC demonstrated that the abnormal findings had disappeared.