Ikuo Katayama - Academia.edu (original) (raw)
Papers by Ikuo Katayama
Progress in Earth and Planetary Science, Jul 22, 2019
Tectonophysics, 2013
ABSTRACT Triaxial deformation experiments on antigorite serpentinite show a systematic correlatio... more ABSTRACT Triaxial deformation experiments on antigorite serpentinite show a systematic correlation between shear stress and effective normal stress over a wide range of pore pressures (50 < Pp < 143 MPa). Under dry conditions using Ar gas as the pore fluid, the steady-state friction coefficient (μ) is estimated to be 0.66 ± 0.01. In contrast, under wet conditions using distilled water as the pore fluid, μ = 0.51 ± 0.01 (i.e., less than under dry conditions). This difference in μ may be caused by charged water on the serpentine surface, which reduces the frictional resistance of the sliding surface in wet environments. The linear correlation between shear stress and effective normal stress suggests that Coulomb's law applies to sliding surfaces during the injection and ejection of pore fluids. This results in a significant mechanical weakening due to elevated pore fluid pressures; consequently, the locations of asperities on plate boundaries may be controlled by the heterogeneous distribution of fluids on the subducting plate interface.
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 23, 2015
Recent studies have shown that metamorphic belts underwent pervasive retrogressive hydration meta... more Recent studies have shown that metamorphic belts underwent pervasive retrogressive hydration metamorphism (ex. Ota et al. 2004; Okamoto and Toriumi 2005 etc. in the Sambagawa metamorphic belt). It is very important to develop the methodology which can deal quantitatively with the progress of metamorphic rehydration reactions. Retrogressive rehydration reactions (1) require the enough supply of external water, and (2) proceed heterogeneously. These make it impossible for the conventional methodologies, which inevitably assume the excess of water and perfect equilibrium in the whole system, to analyze metamorphic rehydration. In this study, we attempted to develop the new methodology of forward analyses of retrogressive rehydration reactions by improving the differential thermodynamic forward modeling (Spear 1993). In differential thermodynamic forward modeling, three types of equations (thermodynamic equilibrium constraints, stoichiometric constraints and mass balance constraints) ar...
Annals of vascular surgery, Jan 15, 2015
An aortic arch aneurysm rarely perforates the pulmonary artery, but once this occurs symptoms of ... more An aortic arch aneurysm rarely perforates the pulmonary artery, but once this occurs symptoms of heart failure may develop rapidly and result in a serious course. Here, we report such a case that was treated with life-saving emergency surgery. The patient was an 86-year-old man in whom aortic arch aneurysm had been pointed out 8 years earlier, but left untreated. In January 2014, dyspnea developed and he visited the emergency unit of our hospital. Continuous murmur was heard on auscultation and aorta-pulmonary artery shunt was noted on transthoracic echocardiography. Chest CT revealed a giant aortic arch aneurysm of size 106 mm that had perforated the left pulmonary artery. Emergency surgery was performed for a diagnosis of acute heart failure associated with perforation of the left pulmonary artery by a giant aortic arch aneurysm. The postoperative course was favorable and the patient was discharged with independent walking on POD 28.
Journal of Geography (Chigaku Zasshi), 2004
Journal of vascular surgery, 2015
It is well-known that the Pacific superplume has been episodically active to form a number of oce... more It is well-known that the Pacific superplume has been episodically active to form a number of oceanic Lips in the Pacific. During the middle Cretaceous time, it has formed Ontong-Jawa, Caribbean plateau, Mid-Pacific seamount chains and others. Moreover, several accreted fragments of those equivalents have been recently recognized as accreted fragments in accretionary orogens around the Pacific rims. Here, we list up a possible candidate which appears as a small piece now but it must have been a huge one equivalent to Ontong-Java size. The Cretaceous Sanbagawa belt in SW Japan is an accretionary complex metamorphosed at high-P/T conditions from 300-900° C and 0.5-2.6 GPa. We have recently completed a new lithotectonic map at 1:5000 scale for the highest grade areas, central Shikoku, with special attention on duplex structure and protolith occurrences. The mapped area consists of pelitic, basic and quartz schists with epidote-amphibolite facies grade, which enclose the Iratsu- and Hig...
Terra Nova
In order to decipher the origin of eclogite in the high-P/T Sanbagawa metamorphic belt, SHRIMP U–... more In order to decipher the origin of eclogite in the high-P/T Sanbagawa metamorphic belt, SHRIMP U–Pb ages of zircons from quartz-bearing eclogite and associated quartz-rich rock (metasandstone) were determined. One zircon core of the quartz-rich rock yields an extremely old provenance age of 1899 ± 79 Ma, suggesting that the core is of detrital origin. Eight other core ages are in the 148–134 Ma range, and are older than the estimated age for trench sedimentation as indicated by the youngest radiolarian fossil age of 139–135 Ma from the Sanbagawa schists. Ages of metamorphic zircon rims (132–112 Ma) from the quartz-rich rock are consistent with metamorphic zircon ages from the quartz-bearing eclogite, indicating that eclogite facies metamorphism peaked at 120–110 Ma. These new data are consistent with both the Iratsu eclogite body and surrounding highest-grade Sanbagawa schists undergoing coeval subduction-zone metamorphism, and subsequent re-equilibration under epidote amphibolite f...
Investigations of fabric analyses are helpful for understanding rheology and seismic properties o... more Investigations of fabric analyses are helpful for understanding rheology and seismic properties of the deep Earth. The results of aspect ratios, angle to the foliation and magnitude of CPOs in a lawsonite blueschist from New Idria serpentinite body, Diablo Range, California indicate the existence of strain localization into glaucophane-rich layer, denoting predominant roles of glaucophane for rheology of blueschist. Similar CPO of each glaucophane and lawsonite in glaucophane-rich and lawsonite-rich layers suggests weak correlations between slip-systems and magnitude of strain. Strong P-wave anisotropy (AVPmax = 25.3%) of glaucophane is calculated from the CPOs, while that of lawsonite exhibits relatively weak anisotropy (AVPmax = 10.7%). Fast P-wave velocity of glaucophane is established along the lineation, which is parallel to the development of the VPmin of lawsonite. This implies the dominant roles of glaucophane and negative affects of lawsonite for compressional wave of the s...
Measurements of shear-wave splitting above the mantle wedge in most subduction zones, including t... more Measurements of shear-wave splitting above the mantle wedge in most subduction zones, including the Japan subduction system, reveal trench-parallel anisotropy, in which the propagation direction of the fast shear-wave is oriented subparallel to the trench; however the delay time (dt) shows marked spatial variations. For example, delay time is ~0.1-0.2 sec in northeast Japan and ~1-2 sec beneath the Ryukyu
Serpentine has a strong crystallographic anisotropy, which is several times greater than olivine,... more Serpentine has a strong crystallographic anisotropy, which is several times greater than olivine, and the occurrence of serpentine is expected where water infiltrates into the mantle. Accordingly, one possible explanation of the spatial variation of seismic anisotropy in subduction zones is the crystal-preferred orientation of serpentine. In the Japan subduction systems, delay time of shear wave splitting is ~1-2 sec
Seismic anisotropy provides clues to understand the flow patterns in the upper mantle. Shear-wave... more Seismic anisotropy provides clues to understand the flow patterns in the upper mantle. Shear-wave splitting measurements reveal that the directions of the fast polarization axis at most subduction zones are oriented perpendicular to the flow direction. Several subduction systems show large delay times (up to 2 sec) that are incompatible with an origin from crystal-preferred orientation (CPO) of olivine in
Journal of Geophysical Research: Solid Earth, 2015
Kyobu geka. The Japanese journal of thoracic surgery, 2015
Minimally invasive cardiac surgery of the mitral valve (MICS-MV) has become the routine approach ... more Minimally invasive cardiac surgery of the mitral valve (MICS-MV) has become the routine approach to mitral valve disease in some centers. We reported early results of 51 cases of MICS-MV. The preoperative variables, intraoperative date and postoperative outcomes of patients undergoing MICS-MV and conventional surgery of the mitral valve were collected from January 2013 to August 2014. Aortic cross clamp and cardio-pulmonary bypass( CPB) time were longer in this series than in the conventional median sternotomy. We experienced complications and 2 patients required mitral valve replacement (MVR) due to failure of repair in initial MICS cases. One case of the patients with infective endocarditis was performed conversion of from MICS to a median sternotomy due to left ventricle(LV) rupture. The early-time outcomes in these patients are acceptable. We think that large number of MICS-MV operations are required to overcome the learning curve.
Kyobu geka. The Japanese journal of thoracic surgery, 2007
We evaluated the results of 213 emergency operations of acute type A aortic dissection in our cen... more We evaluated the results of 213 emergency operations of acute type A aortic dissection in our center from January 2003 to December 2006. They were 101 male and 112 female, and the mean age was 64.6 years. The hospital mortality rate of all cases was 13.6% (29/213). And that of cases with malperfusion was 31.9% (15/47). They consisted of stroke 8/17 (47.1%), myocardial ischemia 5/27 (18.5%) [right coronary artery: 2/22 (9.1%), left main trunk: 3/5 (60.0%)], and intestinal ischemia 2/3 (66.7%). The hospital mortality rate of pulseless electrical activity (PEA) cases was 57.1% (4/7), and that of aortic rupture cases was 33.3% (3/9). On the other hand, the mortality rate of cases with cardiac tamponade alone was 4/45 (8.9%). That of cases without cardiac tamponade and malperfusion was 3/105 (2.9%), and was significantly (p < 0.05) lower than that with malperfusion.
Precambrian Research, 2007
Progress in Earth and Planetary Science, Jul 22, 2019
Tectonophysics, 2013
ABSTRACT Triaxial deformation experiments on antigorite serpentinite show a systematic correlatio... more ABSTRACT Triaxial deformation experiments on antigorite serpentinite show a systematic correlation between shear stress and effective normal stress over a wide range of pore pressures (50 < Pp < 143 MPa). Under dry conditions using Ar gas as the pore fluid, the steady-state friction coefficient (μ) is estimated to be 0.66 ± 0.01. In contrast, under wet conditions using distilled water as the pore fluid, μ = 0.51 ± 0.01 (i.e., less than under dry conditions). This difference in μ may be caused by charged water on the serpentine surface, which reduces the frictional resistance of the sliding surface in wet environments. The linear correlation between shear stress and effective normal stress suggests that Coulomb's law applies to sliding surfaces during the injection and ejection of pore fluids. This results in a significant mechanical weakening due to elevated pore fluid pressures; consequently, the locations of asperities on plate boundaries may be controlled by the heterogeneous distribution of fluids on the subducting plate interface.
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 23, 2015
Recent studies have shown that metamorphic belts underwent pervasive retrogressive hydration meta... more Recent studies have shown that metamorphic belts underwent pervasive retrogressive hydration metamorphism (ex. Ota et al. 2004; Okamoto and Toriumi 2005 etc. in the Sambagawa metamorphic belt). It is very important to develop the methodology which can deal quantitatively with the progress of metamorphic rehydration reactions. Retrogressive rehydration reactions (1) require the enough supply of external water, and (2) proceed heterogeneously. These make it impossible for the conventional methodologies, which inevitably assume the excess of water and perfect equilibrium in the whole system, to analyze metamorphic rehydration. In this study, we attempted to develop the new methodology of forward analyses of retrogressive rehydration reactions by improving the differential thermodynamic forward modeling (Spear 1993). In differential thermodynamic forward modeling, three types of equations (thermodynamic equilibrium constraints, stoichiometric constraints and mass balance constraints) ar...
Annals of vascular surgery, Jan 15, 2015
An aortic arch aneurysm rarely perforates the pulmonary artery, but once this occurs symptoms of ... more An aortic arch aneurysm rarely perforates the pulmonary artery, but once this occurs symptoms of heart failure may develop rapidly and result in a serious course. Here, we report such a case that was treated with life-saving emergency surgery. The patient was an 86-year-old man in whom aortic arch aneurysm had been pointed out 8 years earlier, but left untreated. In January 2014, dyspnea developed and he visited the emergency unit of our hospital. Continuous murmur was heard on auscultation and aorta-pulmonary artery shunt was noted on transthoracic echocardiography. Chest CT revealed a giant aortic arch aneurysm of size 106 mm that had perforated the left pulmonary artery. Emergency surgery was performed for a diagnosis of acute heart failure associated with perforation of the left pulmonary artery by a giant aortic arch aneurysm. The postoperative course was favorable and the patient was discharged with independent walking on POD 28.
Journal of Geography (Chigaku Zasshi), 2004
Journal of vascular surgery, 2015
It is well-known that the Pacific superplume has been episodically active to form a number of oce... more It is well-known that the Pacific superplume has been episodically active to form a number of oceanic Lips in the Pacific. During the middle Cretaceous time, it has formed Ontong-Jawa, Caribbean plateau, Mid-Pacific seamount chains and others. Moreover, several accreted fragments of those equivalents have been recently recognized as accreted fragments in accretionary orogens around the Pacific rims. Here, we list up a possible candidate which appears as a small piece now but it must have been a huge one equivalent to Ontong-Java size. The Cretaceous Sanbagawa belt in SW Japan is an accretionary complex metamorphosed at high-P/T conditions from 300-900° C and 0.5-2.6 GPa. We have recently completed a new lithotectonic map at 1:5000 scale for the highest grade areas, central Shikoku, with special attention on duplex structure and protolith occurrences. The mapped area consists of pelitic, basic and quartz schists with epidote-amphibolite facies grade, which enclose the Iratsu- and Hig...
Terra Nova
In order to decipher the origin of eclogite in the high-P/T Sanbagawa metamorphic belt, SHRIMP U–... more In order to decipher the origin of eclogite in the high-P/T Sanbagawa metamorphic belt, SHRIMP U–Pb ages of zircons from quartz-bearing eclogite and associated quartz-rich rock (metasandstone) were determined. One zircon core of the quartz-rich rock yields an extremely old provenance age of 1899 ± 79 Ma, suggesting that the core is of detrital origin. Eight other core ages are in the 148–134 Ma range, and are older than the estimated age for trench sedimentation as indicated by the youngest radiolarian fossil age of 139–135 Ma from the Sanbagawa schists. Ages of metamorphic zircon rims (132–112 Ma) from the quartz-rich rock are consistent with metamorphic zircon ages from the quartz-bearing eclogite, indicating that eclogite facies metamorphism peaked at 120–110 Ma. These new data are consistent with both the Iratsu eclogite body and surrounding highest-grade Sanbagawa schists undergoing coeval subduction-zone metamorphism, and subsequent re-equilibration under epidote amphibolite f...
Investigations of fabric analyses are helpful for understanding rheology and seismic properties o... more Investigations of fabric analyses are helpful for understanding rheology and seismic properties of the deep Earth. The results of aspect ratios, angle to the foliation and magnitude of CPOs in a lawsonite blueschist from New Idria serpentinite body, Diablo Range, California indicate the existence of strain localization into glaucophane-rich layer, denoting predominant roles of glaucophane for rheology of blueschist. Similar CPO of each glaucophane and lawsonite in glaucophane-rich and lawsonite-rich layers suggests weak correlations between slip-systems and magnitude of strain. Strong P-wave anisotropy (AVPmax = 25.3%) of glaucophane is calculated from the CPOs, while that of lawsonite exhibits relatively weak anisotropy (AVPmax = 10.7%). Fast P-wave velocity of glaucophane is established along the lineation, which is parallel to the development of the VPmin of lawsonite. This implies the dominant roles of glaucophane and negative affects of lawsonite for compressional wave of the s...
Measurements of shear-wave splitting above the mantle wedge in most subduction zones, including t... more Measurements of shear-wave splitting above the mantle wedge in most subduction zones, including the Japan subduction system, reveal trench-parallel anisotropy, in which the propagation direction of the fast shear-wave is oriented subparallel to the trench; however the delay time (dt) shows marked spatial variations. For example, delay time is ~0.1-0.2 sec in northeast Japan and ~1-2 sec beneath the Ryukyu
Serpentine has a strong crystallographic anisotropy, which is several times greater than olivine,... more Serpentine has a strong crystallographic anisotropy, which is several times greater than olivine, and the occurrence of serpentine is expected where water infiltrates into the mantle. Accordingly, one possible explanation of the spatial variation of seismic anisotropy in subduction zones is the crystal-preferred orientation of serpentine. In the Japan subduction systems, delay time of shear wave splitting is ~1-2 sec
Seismic anisotropy provides clues to understand the flow patterns in the upper mantle. Shear-wave... more Seismic anisotropy provides clues to understand the flow patterns in the upper mantle. Shear-wave splitting measurements reveal that the directions of the fast polarization axis at most subduction zones are oriented perpendicular to the flow direction. Several subduction systems show large delay times (up to 2 sec) that are incompatible with an origin from crystal-preferred orientation (CPO) of olivine in
Journal of Geophysical Research: Solid Earth, 2015
Kyobu geka. The Japanese journal of thoracic surgery, 2015
Minimally invasive cardiac surgery of the mitral valve (MICS-MV) has become the routine approach ... more Minimally invasive cardiac surgery of the mitral valve (MICS-MV) has become the routine approach to mitral valve disease in some centers. We reported early results of 51 cases of MICS-MV. The preoperative variables, intraoperative date and postoperative outcomes of patients undergoing MICS-MV and conventional surgery of the mitral valve were collected from January 2013 to August 2014. Aortic cross clamp and cardio-pulmonary bypass( CPB) time were longer in this series than in the conventional median sternotomy. We experienced complications and 2 patients required mitral valve replacement (MVR) due to failure of repair in initial MICS cases. One case of the patients with infective endocarditis was performed conversion of from MICS to a median sternotomy due to left ventricle(LV) rupture. The early-time outcomes in these patients are acceptable. We think that large number of MICS-MV operations are required to overcome the learning curve.
Kyobu geka. The Japanese journal of thoracic surgery, 2007
We evaluated the results of 213 emergency operations of acute type A aortic dissection in our cen... more We evaluated the results of 213 emergency operations of acute type A aortic dissection in our center from January 2003 to December 2006. They were 101 male and 112 female, and the mean age was 64.6 years. The hospital mortality rate of all cases was 13.6% (29/213). And that of cases with malperfusion was 31.9% (15/47). They consisted of stroke 8/17 (47.1%), myocardial ischemia 5/27 (18.5%) [right coronary artery: 2/22 (9.1%), left main trunk: 3/5 (60.0%)], and intestinal ischemia 2/3 (66.7%). The hospital mortality rate of pulseless electrical activity (PEA) cases was 57.1% (4/7), and that of aortic rupture cases was 33.3% (3/9). On the other hand, the mortality rate of cases with cardiac tamponade alone was 4/45 (8.9%). That of cases without cardiac tamponade and malperfusion was 3/105 (2.9%), and was significantly (p < 0.05) lower than that with malperfusion.
Precambrian Research, 2007