Successful Emergency Carotid Endarterectomy after Thrombolysis with Intravenous Recombinant Tissue-Type Plasminogen Activator

Acute internal carotid artery (ICA) occlusion may result in severe disability or death. Revascularization by carotid artery stenting after treatment with intravenous (iv) recombinant tissue-type plasminogen activator (rt-PA) has been documented. However, there are few reports on emergency carotid endarterectomy (CEA) within 24 hours after the iv administration of rt-PA. We treated a 58-year-old man with right ICA occlusion with iv rt-PA. Although partial recanalization of the ICA was obtained, severe stenosis at the origin of the ICA persisted and he developed fluctuating neurological deficits. To prevent progressive stroke he underwent CEA 10.5 hours after rt-PA treatment. Thereafter his blood pressure was strictly controlled under sedation. During and after CEA there were no hemorrhagic complications. Our findings suggest that emergency CEA may be an option to address symptomatic severe residual ICA stenosis even after iv rt-PA therapy delivered in the acute stage

On the transient response of serpentine (antigorite) gouge to stepwise changes in slip velocity under high-temperature conditions

Shear-sliding tests were conducted on serpentine (antigorite) gouge to understand the rheology of serpentine-bearing faults. The experiments were carried out using a constant confining pressure (100 MPa), a constant pore water pressure (30 MPa), and a range of temperatures (from room temperature to 600 degrees C). The transient response in frictional behavior following stepwise changes in the slip velocity were documented at each temperature. Slip rates varied between 0.0115 and 11.5 mu m/s. Both the general level of frictional strength and the transient responses changed drastically at around 450 degrees C. As the temperature increased from 400 degrees C to 450 degrees C, the strength of antigorite rose sharply. The transient response also indicated a change in the mode of deformation from flow-type behavior at temperatures below 400 degrees C to frictional behavior (stick-slip) at temperatures above 450 degrees C-500 degrees C. Although only a limited volume of serpentine was involved in the dehydration reaction, X-ray diffraction analyses and scanning electron microscopy observations showed that forsterite had nucleated in the experimental products at the higher temperatures that were associated with frictional behavior. Submicron-sized, streaky forsterite masses in shear-localized zones may be evidence of shear-induced dehydration that caused strengthening and embrittlement of the gouge. Although antigorite rheology is complicated, the subsequent change in friction coefficient per order-of-magnitude change in sliding velocity increased with both increasing temperature and decreasing velocity, implying that a possible flow mechanism of intragranular deformation became activated

Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 II. Extrapancreatic lesions, differential diagnosis

Published online: 25 March 2014ArticleJOURNAL OF GASTROENTEROLOGY. 49(5):765-784 (2014)journal articl

A history of mild shocks experienced by the regolith particles on hydrated asteroid Ryugu

Micrometeorites, a possible major source of Earth’s water, are thought to form from explosive dispersal of hydrated chondritic materials during impact events on their parental asteroids. However, this provenance and formation mechanism have yet to be directly confirmed using asteroid returned samples. Here, we report evidence of mild shock metamorphism in the surface particles of asteroid Ryugu based on electron microscopy. All particles are dominated by phyllosilicates but lack dehydration textures, which are indicative of shock-heating temperatures below ~500 °C. Microfault-like textures associated with extensively shock-deformed framboidal magnetites and a high-pressure polymorph of Fe–Cr–sulfide have been identified. These findings indicate that the average peak pressure was -2 GPa. The vast majority of ejecta formed during impact on Ryugu-like asteroids would be hydrated materials, larger than a millimetre, originating far from the impact point. These characteristics are inconsistent with current micrometeorite production models, and consequently, a new formation mechanism is required