[Right Atrial Blood Cyst with Patent Foramen Ovale:Report of a Case].

A woman in 70s was diagnosed with lung cancer, and a right atrial mass was discovered incidentally during preoperative examination by contrast-enhanced computed tomography (CT). Transesophageal echocardiography revealed a 20-mm, stemmed, spherical mass with low internal echogenicity and partially high echogenicity extending from the junction of the inferior vena cava to the posterior wall of the right atrium. Patent foramen ovale( PFO) was also confirmed. To avoid embolization and obtain diagnosis, the patient was referred for right atrial tumor resection. Cardiopulmonary bypass was established; the right atrial tumor was removed while the patient was in cardiac arrest. The tumor membrane was thin and easily ruptured, revealing jelly-like blood content and calcified mass. The patient recovered well after surgery and was discharged on day 15. According to the pathological examination, the tumor was a blood cyst. This is an extremely rare case of a blood cyst with PFO.

Recovery of N2O: Energy-Efficient and Structure-Driven Clathrate-Based Greenhouse Gas Separation.

N2O has 300 times more global warming potential than CO2 and is also one of the main stratospheric ozone-depleting substances emitted by human activities such as agriculture, industry, and the combustion of fossil fuels and solid waste. We present here an energy-efficient clathrate-based greenhouse gas-separation (CBGS) technology that can operate at room temperature for selectively recovering N2O from gas mixtures. Clathrate formation between α-form/ß-form hydroquinone (α-HQ/ß-HQ) and gas mixtures reveals guest-specific and structure-driven selectivity, revealing the preferential capture of N2O in ß-HQ and the molecular sieving characteristics of α-HQ. With a maximum gas storage capacity and cage occupancy of 54.1 cm3 g-1 and 0.86, respectively, HQ clathrate compounds including N2O are stable at room temperature and atmospheric pressure and thus can be easily synthesized, treated, and recycled via commercial CBGS processes. High selectivity for N2O recovery was observed during ß-HQ clathrate formation from N2O/N2 gas mixtures with N2O concentrations exceeding 20%, whereas α-HQ traps only N2 molecules from gas mixtures. Full characterization using X-ray diffraction, scanning electron microscopy, Raman spectroscopy, solid-state nuclear magnetic resonance, and compositional analysis and the formation kinetics of HQ clathrates was conducted to verify the peculiar selectivity behavior and to design the conceptual CBGS process. These results provide a new playground on which to tailor host-guest materials and develop commercial processes for the recovery and/or sequestration of greenhouse gases.

Effect of Ammonia on Methane Hydrate Stability under High-Pressure and High-Temperature Conditions.

High-pressure experiments were conducted to investigate the stability and phase transition of methane hydrate (MH) in the water-methane-ammonia system at room-to-high temperatures employing Raman spectroscopy and synchrotron X-ray powder diffraction, in combination with an externally heated diamond anvil cell. The results revealed that, at room temperature, MH undergoes phase transitions from MH-I to MH-II at ∼1.0 GPa and from MH-II to MH-III at ∼2.0 GPa. These transition behaviors are consistent with those in the water-methane system, which indicates that ammonia has a negligible effect on a series of phase transitions of MH. Contrarily, a sequential in situ Raman spectroscopy revealed that ammonia affects the stability of MH-III under high pressure and high temperature: the dissociation temperature of MH-III was more than 10 K lower in the water-methane-ammonia system than in the water-methane system. These findings aid in improving the internal structural models of icy bodies and estimating the origin of their atmospheric methane.

Structural evolution of methane hydrate under pressures up to 134 GPa.

High-pressure experiments were performed to understand the structural evolution of methane hydrate (MH) up to 134 GPa using x-ray powder diffraction (XRD) and Raman spectroscopy with diamond anvil cells. XRD revealed the distinct changes in the diffraction lines of MH owing to phase transition from a guest-ordered state phase [MH-III(GOS)] to a new high-pressure phase (MH-IV) at 33.8-57.7 GPa. MH-IV was found to be stable up to at least 134 GPa without decomposition into solid methane and high-pressure ices. Raman spectroscopy showed the splits in the C-H vibration modes ν3 and ν1 of guest methane molecules in filled-ice Ih (MH-III) at 12.7 GPa and 28.6 GPa, respectively. These splits are caused by orientational ordering of guest methane molecules contained in the hydrate structure, as observed in a previous study. These results suggest that the structural evolution of the filled-ice structure of MH is caused by successive orientational ordering of guest methane molecules, thereby inducing changes in the host framework formed by water molecules.

[Coil Embolization for an Aberrant Left Subclavian Artery Aneurysm with Kommerell's Diverticulum;Report of a Case].

A 67-year-old woman encountered a traffic accident and had chest computed tomography(CT) examination. It revealed a 24 mm Kommerell's diverticulum associated with a right-sided aortic arch and a 15 mm saccular aneurysm of an aberrant left subclavian artery. We performed intra-aneurysmal coil embolization for the left subclavian artery aneurysm after a balloon occlusion test of the left subclavian artery. The postoperative course was uneventful.

In situ Raman and X-ray diffraction studies on the high pressure and temperature stability of methane hydrate up to 55 GPa.

High-temperature and high-pressure experiments were performed under 2-55 GPa and 298-653 K using in situ Raman spectroscopy and X-ray diffraction combined with externally heated diamond anvil cells to investigate the stability of methane hydrate. Prior to in situ experiments, the typical C-H vibration modes of methane hydrate and their pressure dependence were measured at room temperature using Raman spectroscopy to make a clear discrimination between methane hydrate and solid methane which forms through the decomposition of methane hydrate at high temperature. The sequential in situ Raman spectroscopy and X-ray diffraction revealed that methane hydrate survives up to 633 K and 40.3 GPa and then decomposes into solid methane and ice VII above the conditions. The decomposition curve of methane hydrate estimated by the present experiments is >200 K lower than the melting curves of solid methane and ice VII, and moderately increases with increasing pressure. Our result suggests that although methane hydrate may be an important candidate for major constituents of cool exoplanets and other icy bodies, it is unlikely to be present in the ice mantle of Neptune and Uranus, where the temperature is expected to be far beyond the decomposition temperatures.

Analysis of Computational Fluid Dynamics and Particle Image Velocimetry Models of Distal-End Side-to-Side and End-to-Side Anastomoses for Coronary Artery Bypass Grafting in a Pulsatile Flow.

BACKGROUND: Intimal hyperplasia (IH) is a major cause of graft failure. Hemodynamic factors such as stagnation and disturbed blood flow are involved in IH formation. The aim of this study is to perform a comparative analysis of distal-end side-to-side (deSTS) and end-to-side (ETS) anastomoses using computational fluid dynamics (CFD) after validating the results via particle image velocimetry (PIV).Methods and Results:We investigated the characteristics of our target flow fields using CFD under steady and pulsatile flows. CFD via PIV under steady flow in a 10-times-actual-size model was validated. The CFD analysis revealed a recirculation zone in the heel region in the deSTS and ETS anastomoses and at the distal end of the graft, and just distal to the toe of the host artery in the deSTS anastomoses. The recirculation zone sizes changed with the phase shift. We found regions of low wall shear stress and high oscillating shear index in the same areas. The PIV and CFD results were similar. CONCLUSIONS: It was demonstrated that the hemodynamic characteristics of CFD and PIV is the difference between the deSTS and ETS anastomoses; that is, the deSTS flow peripheral to the distal end of the graft, at the distal end and just distal to the toe of the host artery is involved in the IH formation.

Time-resolved X-ray diffraction and Raman studies of the phase transition mechanisms of methane hydrate.

The mechanisms by which methane hydrate transforms from an sI to sH structure and from an sH to filled-ice Ih structure were examined using time-resolved X-ray diffractometry (XRD) and Raman spectroscopy in conjunction with charge-coupled device camera observation under fixed pressure conditions. The XRD data obtained for the sI-sH transition at 0.8 GPa revealed an inverse correlation between sI and sH, suggesting that the sI structure is replaced by sH. Meanwhile, the Raman analysis demonstrated that although the 12-hedra of sI are retained, the 14-hedra are replaced sequentially by additional 12-hedra, modified 12-hedra, and 20-hedra cages of sH. With the sH to filled-ice Ih transition at 1.8 GPa, both the XRD and Raman data showed that this occurs through a sudden collapse of the sH structure and subsequent release of solid and fluid methane that is gradually incorporated into the filled-ice Ih to complete its structure. This therefore represents a typical reconstructive transition mechanism.

Hydration structures of lactic acid: characterization of the ionic clathrate hydrate formed with a biological organic acid anion.

Ionic clathrate hydrates are water-based materials that have unique properties, such as a wide range of melting temperatures and high gas capacities. In their structure, water molecules coordinate around ionic substances, which is regarded as the actual hydration structure and also linking of the hydrate clusters, giving insight into the dynamics of the water molecules and ions. This paper reports the synthesis and characterization of the ionic clathrate hydrate of tetra-n-butylammonium lactate (TBAL), the anion of which is a biological organic material. Phase equilibrium measurements and optical observations of the crystal morphology and crystal structure analysis were performed. The TBAL hydrate has a melting temperature of 284.8 K suitable for cool energy storage applications. The actual hydration patterns around a lactate anion are shown in the form of ionic clathrate hydrate structure.

Left ventricular unloading therapy using Impella 5.5 after emergency surgery for acute myocardial infarction mechanical complication: a case report.

BACKGROUND: Following an acute myocardial infarction (AMI), surgery for left ventricular free wall rupture (LVFWR) and ventricular septal rupture (VSR) has a high in-hospital mortality rate, which has not improved significantly over time. Unloading the LV is critical to preventing excessive stress on the repair site and avoiding problems such as bleeding, leaks, patch dehiscence, and recurrence of LVFWR and VSR because the tissue is so fragile. We present two cases of patients who used Impella 5.5 for LV unloading following emergency surgery for AMI mechanical complications. CASE PRESENTATION: A 76-year-old male STEMI patient underwent fibrinolysis of the distal right coronary artery. Three days later, he passed out and went into shock. Echocardiography revealed a cardiac tamponade. We found an oozing-type LVFWR on the posterolateral wall and treated it with a non-suture technique using TachoSil. Before the patient was taken off CPB, Impella 5.5 was inserted into the LV via a 10 mm synthetic graft connected to the right axillary artery. We kept the flow rate above 4.0 to 4.5 L/min until POD 3 to reduce LV wall tension while minimizing pulsatility. On POD 6, we weaned the patient from Impella 5.5. A postoperative cardiac CT scan showed no contrast leakage from the LV. However, a cerebral hemorrhage on POD 4 during heparin administration complicated his hospitalization. Case 2: A diagnosis of cardiogenic shock caused by STEMI occurred in an 84-year-old male patient, who underwent PCI of the LAD with IABP support. Three days after PCI, echocardiography revealed VSR, and the patient underwent emergency VSR repair with two separate patches and BioGlue applied to the suture line between them. Before weaning from CPB, we implanted Impella 5.5 in the LV and added venoarterial extracorporeal membrane oxygenation (VA-ECMO) support for right heart failure. The postoperative echocardiography revealed no residual shunt. CONCLUSIONS: Patients undergoing emergency surgery for mechanical complications of AMI may find Impella 5.5 to be an effective tool for LV unloading. The use of VA-ECMO in conjunction with Impella may be an effective strategy for managing VSR associated with concurrent right-sided heart failure.

Design of closed loop for reproduction of gas-dominated hydrate flow.

The study presents a novel setup for measuring the flow regime of hydrate particles in a gas-dominated flow, which is of interest for applications such as natural gas transportation. A closed-flow loop, driven by a novel internal fan, enables continuous observation of hydrate particle behavior in a gas flow. The experimental setup allows the production and insertion of HFC134a gas hydrate particles with diameters of 10-50 µm into the gas flow loop via a bypass loop. The performance curve of the internal fan is validated, and its suitability for achieving the required flow speed (5 m/s) is demonstrated. Through an observation window using camera systems, the flow regime of glass beads is successfully visualized and analyzed. To validate the experimental data, a coupled computational fluid dynamics-discrete element method model is used to simulate the particle flow density distribution. The study findings demonstrate the effectiveness of the experimental setup in characterizing the flow regime of hydrate particles in a gas-dominated flow.

Phase changes of filled ice Ih methane hydrate under low temperature and high pressure.

Low-temperature and high-pressure experiments were performed with filled ice Ih structure of methane hydrate under 2.0-77.0 GPa and 30-300 K using diamond anvil cells and a helium-refrigeration cryostat. In situ X-ray diffractometry revealed distinct changes in the compressibility of the axial ratios of the host framework with pressure. Raman spectroscopy showed a split in the C-H vibration modes of the guest methane molecules, which was previously explained by the orientational ordering of the guest molecules. The pressure and temperature conditions at the split of the vibration modes agreed well with those of the compressibility change. The results indicate the following: (i) the orientational ordering of the guest methane molecules from an orientationally disordered state occurred at high pressures and low temperatures; and (ii) this guest ordering led to anisotropic contraction in the host framework. Such guest orientational ordering and subsequent anisotropic contraction of the host framework were similar to that reported previously for filled ice Ic hydrogen hydrate. Since phases with different guest-ordering manners were regarded as different phases, existing regions of the guest disordered-phase and the guest ordered-phase were roughly estimated by the X-ray study. In addition, above the pressure of the guest-ordered phase, another high-pressure phase developed in the low-temperature region. The deuterated-water host samples were also examined, and the influence of isotopic effects on guest ordering and phase transformation was observed.

Structural changes of filled ice Ic hydrogen hydrate under low temperatures and high pressures from 5 to 50 GPa.

Low-temperature and high-pressure experiments were performed on the filled ice Ic structure of hydrogen hydrate at previously unexplored conditions of 5-50 GPa and 30-300 K using diamond anvil cells and a helium-refrigeration cryostat. In situ x-ray diffractometry revealed that the cubic filled ice Ic structure transformed to tetragonal at low temperatures and high pressures; the axis ratio of the tetragonal phase changed depending on the pressure and temperature. These results were consistent with theoretical predictions performed via first principle calculations. The tetragonal phase was determined to be stable above 20 GPa at 300 K, above 15 GPa at 200 K, and above 10 GPa at 100 K. Further changes in the lattice parameters were observed from about 45-50 GPa throughout the temperature region examined, which suggests the transformation to another high-pressure phase above 50 GPa. In our previous x-ray study that was performed up to 80 GPa at room temperature, a similar transformation was observed above 50 GPa. In this study, the observed change in the lattice parameters corresponds to the beginning of that transformation. The reasons for the transformation to the tetragonal structure are briefly discussed: the tetragonal structure might be induced due to changes in the vibrational or rotational modes of the hydrogen molecules under low temperature and high pressure.

Total arch replacement and frozen elephant trunk for acute type A aortic dissection.

OBJECTIVE: The present study aimed to evaluate the outcomes of total aortic arch replacement with proximalization of distal anastomosis using the frozen elephant trunk technique with the J Graft FROZENIX (Japan Lifeline, Tokyo, Japan) and Gelweave Lupiae (Vascutek Terumo Inc, Scotland, United Kingdom) graft (distal anastomosis performed in zones 1 and 2) in patients with acute Stanford type A acute aortic dissection. METHODS: A total of 50 patients underwent total aortic arch replacement using the frozen elephant trunk technique, deploying the J Graft FROZENIX into zone 1 or 2 (zone 1: n = 17, zone 2: n = 33) in combination with the Gelweave Lupiae graft for acute Stanford type A acute aortic dissection. Patient characteristics, intraoperative data, and early and midterm outcomes were analyzed. RESULTS: The overall in-hospital mortality rate was 4% (2 patients). The in-hospital mortality rate in patients with visceral malperfusion was 11% (1/9). There were no patients with paraplegia and stent graft-induced new entry. Resection or closure of the most proximal entry tear was achieved in 100% of 42 patients who had postoperative computed tomography. The overall survival was 87.9%, 84.1%, and 84.1% at 1, 2, and 3 years, respectively. However, 1 patient required endovascular extension for the dilatation of the descending thoracic aorta 4 months after the initial surgery. CONCLUSIONS: Total aortic arch replacement with the frozen elephant trunk technique (zone 1-2) and Gelweave Lupiae graft was safe and effective in simplifying surgery for acute Stanford type A acute aortic dissection.

Oxaliplatin-induced lung injury with allergic reaction.

A 79-year-old man was diagnosed as stage IV colon cancer and treated with a modified FOLFOX6 (mFOLFOX6) regimen. On the 12th cycle, we observed erythema and dyspnea. Radiographs showed ground grass opacities. Blood tests showed elevated levels of eosinophils and immunoglobulin E. We diagnosed this finding as response to drug allergy and administered high-dose methylprednisolone. The treatment was successful and he was discharged. The drug lymphocyte stimulating test against oxaliplatin was positive, indicating a type I and IV allergic reaction due to oxaliplatin. Regimens including oxaliplatin must be carefully monitored and frequent blood tests and chest radiographs are needed.

Cardiac haemangioma treated with surgical resection involving reconstruction of the right ventricle.

A right ventricular cardiac tumour was incidentally detected in a 50-year-old woman during medical check-up. Transthoracic echocardiography, computed tomography and magnetic resonance imaging revealed that the right ventricular tumour was widely attached to the free wall of the right ventricle and extended to the right ventricular outflow tract. The tumour was excised surgically, and the postoperative course was uneventful. Histological examination revealed that the tumour was a cardiac haemangioma.

Partial aortic root remodeling for chronic aortic dissection with coronary intimal tear.

While there are many reports on partial aortic root remodeling, it is rarely performed for chronic aortic dissection of the coronary artery. This report presents a case of a 69-year-old man incidentally diagnosed with aortic dissection during routine checkup. He had a history of percutaneous coronary intervention from the left main trunk to the left anterior descending artery and left circumflex artery. Computed tomography revealed a chronic type A aortic dissection with an aneurysmal aortic root. The false lumen of the Valsalva sinus originated from the left anterior descending artery and expanded largely to the non-coronary Valsalva sinus. We performed partial aortic root remodeling, resecting the dissected non-coronary Valsalva sinus. The postoperative course was uneventful. Partial aortic root remodeling was effective, but its use might be controversial for chronic aortic dissection without resection of the primary entry of the left anterior descending artery. Moreover, close follow-up is required.

Diamond formation from methane hydrate under the internal conditions of giant icy planets.

Hydrocarbon chemistry in the C-O-H system at high pressure and high temperature is important for modelling the internal structure and evolution of giant icy planets, such as Uranus and Neptune, as their interiors are thought to be mainly composed of water and methane. In particular, the formation of diamond from the simplest hydrocarbon, i.e., methane, under the internal conditions of these planets has been discussed for nearly 40 years. Here, we demonstrate the formation of diamond from methane hydrate up to 3800 K and 45 GPa using a CO2 laser-heated diamond anvil cell combined with synchrotron X-ray diffraction, Raman spectroscopy, and scanning electron microscopy observations. The results show that the process of dissociation and polymerisation of methane molecules to produce heavier hydrocarbons while releasing hydrogen to ultimately form diamond proceeds at milder temperatures (~ 1600 K) and pressures (13-45 GPa) in the C-O-H system than in the C-H system due to the influence of water. Our findings suggest that diamond formation can also occur in the upper parts of the icy mantles of giant icy planets.

Phase changes of CO2 hydrate under high pressure and low temperature.

High pressure and low temperature experiments with CO(2) hydrate were performed using diamond anvil cells and a helium-refrigeration cryostat in the pressure and temperature range of 0.2-3.0 GPa and 280-80 K, respectively. In situ x-ray diffractometry revealed that the phase boundary between CO(2) hydrate and water+CO(2) extended below the 280 K reported previously, toward a higher pressure and low temperature region. The results also showed the existence of a new high pressure phase above approximately 0.6 GPa and below 1.0 GPa at which the hydrate decomposed to dry ice and ice VI. In addition, in the lower temperature region of structure I, a small and abrupt lattice expansion was observed at approximately 210 K with decreasing temperature under fixed pressures. The expansion was accompanied by a release of water content from the sI structure as ice Ih, which indicates an increased cage occupancy. A similar lattice expansion was also described in another clathrate, SiO(2) clathrate, under high pressure. Such expansion with increasing cage occupancy might be a common manner to stabilize the clathrate structures under high pressure and low temperature.

Totally endoscopic closure of an atrial septal defect using the da Vinci Surgical System: report of four cases.

This report presents four cases of totally endoscopic closure of an atrial septal defect using the da Vinci Surgical System (Intuitive Surgical, Mountain View, CA, USA). The patients were diagnosed with an ostium secundum atrial septal defect and elected to undergo minimally invasive surgery. A cardiopulmonary bypass was established via cannulation of the femoral vessel and jugular vein, and blood cardioplegic arrest was induced using a transthoracic cross-clamp. The mean extracorporeal circulation and cardiac arrest times were 86 +/- 21 and 22 +/- 8 min, respectively. No patient experienced pain after surgery, and all were fast-tracked for early discharge and released on postoperative day 3. No intraoperative or postoperative complications occurred. This procedure permitted a short hospital stay, quick return to an active lifestyle, and had an excellent cosmetic outcome. The success of this procedure therefore encourages that this procedure should be considered as day surgery.