Kinetic analysis of silicon-lithium alloying reaction in silicon single crystal using soft X-ray absorption spectroscopy.

Silicon has been considered to be one of the most promising anode active materials for next-generation lithium-ion batteries due to its large theoretical capacity (4200 mA h g-1, Li22Si5). However, silicon anodes suffer from degradation due to large volume expansion and contraction. To control the ideal particle morphology, an experimental method is required to analyze anisotropic diffusion and surface reaction phenomena. This study investigates the anisotropy of the silicon-lithium alloying reaction using electrochemical measurements and Si K-edge X-ray absorption spectroscopy on silicon single crystals. During the electrochemical reduction process in lithium-ion battery systems, the continuous formation of solid electrolyte interphase (SEI) films prevents the achievement of steady-state conditions. Instead, the physical contact between silicon single crystals and lithium metals can prevent the effect of SEI formation. The apparent diffusion coefficient and the surface reaction coefficient are determined from the progress of the alloying reaction analyzed by X-ray absorption spectroscopy. While the apparent diffusion coefficients show no clear anisotropy, the apparent surface reaction coefficient of Si (100) is more significant than that of Si (111). This finding indicates that the surface reaction of silicon governs the anisotropy of practical lithium alloying reaction for silicon anodes.

Synthesis of Ca(OH)2 and Na2CO3 through anion exchange between CaCO3 and NaOH: effect of reaction temperature.

The CO2 released upon calcination of limestone accounts for the largest portion of the emissions from the cement, lime, and slaked lime manufacturing industries. Our previous works highlighted the possibility for a no-combustion decarbonisation of CaCO3 through reaction with NaOH solutions to produce Ca(OH)2 at ambient conditions, while sequestrating the process CO2 in a stable mineral Na2CO3·H2O/Na2CO3. In this study, the effect of temperature was assessed within the range of 45-80 °C, suggesting that the process is robust and only slightly sensitive to temperature fluctuations. The proportioning of the precipitated phases Na2CO3·H2O/Na2CO3 was also assessed at increasing NaOH molalities and temperatures, with the activity of water playing a crucial role in phase equilibrium. The activation energy (E a) of different CaCO3 : NaOH : H2O systems was assessed between 7.8 kJ·mol-1 and 32.1 kJ·mol-1, which is much lower than the conventional calcination route. A preliminary energy balance revealed that the chemical decarbonisation route might be ∼4 times less intensive with respect to the thermal one. The present work offers a further understanding of the effect of temperature on the process with the potential to minimise the emissions from several energy-intensive manufacturing processes, and correctly assess eventual industrial applicability.

Effect of Impurities on the Decarbonization of Calcium Carbonate Using Aqueous Sodium Hydroxide.

Decarbonizing calcium carbonate (CaCO3) is a crucial step for a wide range of major industrial processes and materials, including Portland cement (PC) production. Apart from the carbon footprint linked to fuel combustion, the process CO2 embodied within CaCO3 represents the main concern for the sustainability of production. Our recent works demonstrated that it is possible to avoid both the fuel and process CO2 by reacting CaCO3 with aqueous NaOH and obtain Ca(OH)2 and Na2CO3·xH2O (x = 0 and 1). This present study provides a further understanding of the process by testing different raw calcareous sources. A high decarbonization (∼80%) of CaCO3 was achieved for silica-rich chalk, whereas a lower extent was obtained (∼50%) for limestone. To understand the difference in their reaction behavior, the effect of impurities was studied. The effects of the major impurities (Si, Al, and Fe) were found to be marginal, which is advantageous to process industrial grade materials, while the morphology of the raw materials presents a significant impact. The applicability of our decarbonization technology was also demonstrated on magnesite (MgCO3).

Decarbonisation of calcium carbonate in sodium hydroxide solutions under ambient conditions: effect of residence time and mixing rates.

The decarbonisation of CaCO3 is essential for the production of lime (Ca(OH)2 and CaO), which is a commodity required in several large industries and the main precursor for cement production. CaCO3 is usually decarbonised at high temperatures, generating gaseous CO2 which will require post-process capture to minimise its release into the environment. We have developed a new process that can decarbonise CaCO3 under ambient conditions, while sequestering the CO2 as Na2CO3·H2O or Na2CO3 in the same stage. Here, the effects of increasing stirring rates and residence times on reaction efficiency of the key reaction occurring between CaCO3 and NaOH solution are studied. It is shown that the reaction is enhanced at lower stirring rates and longer residence times up to 300 seconds of contact between the reactants. The mass balance performed for Ca and CO2 revealed that up to the 95% of the process CO2 embodied in CaCO3 was sequestered, with maximum capture rate assessed at nn moles CO2 captured per second of reaction progress. A deeper insight into the precipitation of Na2CO3·H2O or Na2CO3 under different reaction conditions was gained, and SEM-EDX analysis enabled the observation of the reaction front by detection of Na migrating towards inner regions of partially-reacted limestone chalk particles.

Endovascular treatment for mycotic aneurysm using pyoktanin- applied devices.

BACKGROUND: Mycotic thoracic aortic aneurysm is an extremely rare but serious disease because it can easily rupture and has a high mortality rate. The standard therapy for it comprises graft replacement and debridement using systemic antibiotics; nonetheless, this has a high mortality rate and complications. Endovascular aortic repair is considered a bridging therapy before open surgery. However, we have used it at our institution for the radical treatment of mycotic thoracic aortic aneurysm utilizing pyoktanin (methylrosanilide chloride)-applied devices. Thus, the aim of this study was to report our clinical experience with pyoktanin-applied thoracic endovascular aortic repair for the treatment of mycotic thoracic aortic aneurysm, including its effects. METHODS: From April 2017 to July 2019, we performed thoracic endovascular aortic repair using pyoktanin for eight cases of mycotic thoracic aortic aneurysm using Valiant®. During device preparation before insertion, pyoktanin was flushed from the side port instead of saline containing heparin. RESULTS: There were no operative deaths, recurrences of infection, or major complications. Two cases died from pneumonia and cancer; the other six cases were alive during the follow-up period. CONCLUSIONS: Pyoktanin-applied thoracic endovascular aortic repair for mycotic thoracic aortic aneurysm treatment is effective. However, the appropriate use of antibiotics and bundled therapy is necessary at present.

[Thoracic Endovascular Aortic Repair and Abdominal Aorta Replacement to Treat Stanford Type B Acute Aortic Dissection Extending through an Abdominal Aortic Aneurysm;Report of a Case].

A 69-year-old man developed sudden-onset chest and back pain and was brought to our hospital. Enhanced computed tomography (CT) revealed acute Stanford type B aortic dissection extending from the distal aortic arch to a 72 mm abdominal aortic aneurysm( AAA). The acute phase was managed by antihypertensive therapy, and the patient was followed up. Twenty days after the onset of aortic dissection, entry closure of aortic dissection by thoracic endovascular aortic repair and abdominal aorta replacement were performed simultaneously. Aorta remodeling was confirmed by postoperative CT, and the patient's postoperative course was uneventful. In the treatment of patients with acute aortic dissection and AAA, surgical intervention timing and strategy must be considered carefully.

[Resection of Anterior Mediastinal Tumor Followed by Left Brachiocephalic Vein Reconstruction;Report of a Case].

A 65-year-old man was referred to our hospital because of an abnormal shadow on a chest radiogram. Swelling of the face and upper limbs were noted. Enhanced computed tomography showed a 62×101 mm mass in the anterior mediastinum with invasion to the superior vena cava (SVC) and the right upper lobe of the lung. Surgical resection through a sternotomy was performed. The mediastinal tumor was resected along with the left brachiocephalic vein, the part of SVC wall and the partial right upper lobe of the lung with a clamp on the proximal SVC, followed by a left brachiocephalic vein reconstruction. There has been no evidence of recurrence after 1 year. This procedure may be an efficacious technical option in case of anterior mediastinal invasive tumor.

Production and properties of ferrite-rich CSAB cement from metallurgical industry residues.

Blast furnace slag from the steel industry is commercially utilized as a cement replacement material without major processing requirements; however, there are many unutilized steel production slags which differ considerably from the blast furnace slag in chemical and physical properties. In this study, calcium sulfoaluminate belite (CSAB) cement clinkers were produced using generally unutilized metallurgical industry residues: AOD (Argon Oxygen Decarburisation) slag from stainless steel production, Fe slag from zinc production, and fayalitic slag from nickel production. CSAB clinker with a target composition of ye'elimite-belite-ferrite was produced by firing raw materials at 1300 °C. The phase composition of the produced clinkers was identified using quantitative XRD analyses, and the chemical composition of the clinker phases produced was established using FESEM-EDS and mechanical properties were tested through compressive strength test. It is demonstrated that these metallurgical residues can be used successfully as alternative raw materials for the production of CSAB cement that can be used for special applications. In addition, it is shown that the available quantities of these side-streams are enough for significant replacement of virgin raw materials used in cement production.

[Emergent Endovascular Treatment of Spontaneous Rupture of the Thoracic Aorta].

Spontaneous rupture of the thoracic aorta is a rare disease with a poor prognosis without obvious trauma, aortic aneurysm and aortic dissection. We report 2 cases of successful endovascular aortic repair for spontaneous rupture of the thoracic aorta. Case 1:A 79-year-old man was referred to our hospital complaining of general fatigue. He returned home without any obvious abnormalities in blood tests and computed tomography (CT). The patient was aware of dizziness and fluttering in the early morning the next day, and was transported to the hospital by shock vital. CT showed rupture of descending aorta, so we performed emergent thoracic endovascular aortic repair (TEVAR). Postoperatively, the patient progressed without paraplegia and was transferred to other hospital on the 15th day of hospital for the purpose of rehabilitation. Case 2:A 87-year-old woman was admitted to hospital with suspected pyelonephritis, but his respiratory status was gradually exacerbated. CT showed a rupture of the thoracic aorta at the distal arch. Ten days ago, CT showed no findings suggestive of aneurysm and dissection at the same site of aorta. We performed emergency TEVAR. She was removed from mechanical ventilation on the 4th postoperative day. We are continuing rehabilitation treatment now.

[Concomitant Atrial Septal Defect Closure and Repair of Pectus Excavatum in a 50-year-old Patient;Report of a Case].

We report a case of atrial septal defect (ASD) with severe pectus excavatum. A 50-year-old female had a stroke due to paradoxical embolism from deep vein thrombosis thorough ASD. Her preoperative computed tomography(CT) revealed a severe pectus excavatum (Haller CT index 28.6). The patient underwent ASD closure and repair of the pectus excavatum concomitantly. Median full sternotomy was performed for ASD closure. And we adopted sterno-costal elevation for pectus excavatum repair. Cartilages of the 3rd to the 7th rib were segmentally resected and the remainders were re-sutured to the sternum. The operation was performed uneventfully. The postoperative echocardiogram revealed no residual shunt. And the deformity of the anterior chest wall was remarkably lessen.

Blast furnace slag-Mg(OH)2 cements activated by sodium carbonate.

The structural evolution of a sodium carbonate activated slag cement blended with varying quantities of Mg(OH)2 was assessed. The main reaction products of these blended cements were a calcium-sodium aluminosilicate hydrate type gel, an Mg-Al layered double hydroxide with a hydrotalcite type structure, calcite, and a hydrous calcium aluminate phase (tentatively identified as a carbonate-containing AFm structure), in proportions which varied with Na2O/slag ratios. Particles of Mg(OH)2 do not chemically react within these cements. Instead, Mg(OH)2 acts as a filler accelerating the hardening of sodium carbonate activated slags. Although increased Mg(OH)2 replacement reduced the compressive strength of these cements, pastes with 50 wt% Mg(OH)2 still reached strengths of ∼21 MPa. The chemical and mechanical characteristics of sodium carbonate activated slag/Mg(OH)2 cements makes them a potentially suitable matrix for encapsulation of high loadings of Mg(OH)2-bearing wastes such as Magnox sludge.

Effects of Transplanted Human Cord Blood-Mononuclear Cells on Pulmonary Hypertension in Immunodeficient Mice and Their Distribution.

OBJECTIVES: To investigate the effects of human umbilical cord blood-derived mononuclear cell (hUCB-MNC) transplantation on pulmonary hypertension (PH) induced by monocrotaline (MCT) in immunodeficient mice and their distribution. METHODS: MCT was administered to BALB/c Slc-nu/nu mice, and PH was induced in mice 4 weeks later. Fresh hUCB-MNCs harvested from a human donor after her delivery were injected intravenously into those PH mice. The medial thickness of pulmonary arterioles, ratio of right ventricular to septum plus left ventricular weight (RV/S+LV), and ratio of acceleration time to ejection time of pulmonary blood flow waveform (AT/ET) were determined 4 weeks after hUCB-MNC transplantation. To reveal the incorporation into the lung, CMTMR-labeled hUCB-MNCs were observed in the lung by fluorescent microscopy. DiR-labeled hUCB-MNCs were detected in the lung and other organs by bioluminescence images. RESULTS: Medial thickness, RV/S+LV and AT/ET were significantly improved 4 weeks after hUCB-MNC transplantation compared with those in mice without hUCB-MNC transplantation. CMTMR-positive hUCB-MNCs were observed in the lung 3 hours after transplantation. Bioluminescence signals were detected more strongly in the lung than in other organs for 24 hours after transplantation. CONCLUSIONS: The results indicate that hUCB-MNCs are incorporated into the lung early after hUCB-MNC transplantation and improve MCT-induced PH. J. Med. Invest. 64: 43-49, February, 2017.

Ionic Conduction in Lithium Ion Battery Composite Electrode Governs Cross-sectional Reaction Distribution.

Composite electrodes containing active materials, carbon and binder are widely used in lithium-ion batteries. Since the electrode reaction occurs preferentially in regions with lower resistance, reaction distribution can be happened within composite electrodes. We investigate the relationship between the reaction distribution with depth direction and electronic/ionic conductivity in composite electrodes with changing electrode porosities. Two dimensional X-ray absorption spectroscopy shows that the reaction distribution is happened in lower porosity electrodes. Our developed 6-probe method can measure electronic/ionic conductivity in composite electrodes. The ionic conductivity is decreased for lower porosity electrodes, which governs the reaction distribution of composite electrodes and their performances.

Extraction of Mg(OH)2 from Mg silicate minerals with NaOH assisted with H2O: implications for CO2 capture from exhaust flue gas.

The utilisation of Mg(OH)2 to capture exhaust CO2 has been hindered by the limited availability of brucite, the Mg(OH)2 mineral in natural deposits. Our previous study demonstrated that Mg(OH)2 can be obtained from dunite, an ultramafic rock composed of Mg silicate minerals, in highly concentrated NaOH aqueous systems. However, the large quantity of NaOH consumed was considered an obstacle for the implementation of the technology. In the present study, Mg(OH)2 was extracted from dunite reacted in solid systems with NaOH assisted with H2O. The consumption of NaOH was reduced by 97% with respect to the NaOH aqueous systems, maintaining a comparable yield of Mg(OH)2 extraction, i.e. 64.8-66%. The capture of CO2 from a CO2-N2 gas mixture was tested at ambient conditions using a Mg(OH)2 aqueous slurry. Mg(OH)2 almost fully dissolved and reacted with dissolved CO2 by forming Mg(HCO3)2 which remained in equilibrium storing the CO2 in the aqueous solution. The CO2 balance of the process was assessed from the emissions derived from the power consumption for NaOH production and Mg(OH)2 extraction together with the CO2 captured by Mg(OH)2 derived from dunite. The process resulted as carbon neutral when dunite is reacted at 250 °C for durations of 1 and 3 hours and CO2 is captured as Mg(HCO3)2.

PPAR-γ agonist attenuates inflammation in aortic aneurysm patients.

BACKGROUND AND OBJECTIVE: Peroxisome proliferator-activated receptor (PPAR) -γ agonist, which is an anti-diabetes drug and reduces expression of tumor necrosis factor (TNF)-α, reported to have the effects for anti-inflammation in our body. In cardiovascular fields, this PPAR-γ agonist already reported to suppress progression of coronary atherosclerosis. Various cytokines, which is secreted from fat tissues around artery, promote atherosclerosis and/or aneurysmal changes in aorta/artery. Objective of our study is to clarify whether PPAR-γ agonist has anti-inflammatory effects in aorta of patients with aortic aneurysm (AA). PATIENTS AND METHODS: The medical ethics committee in Tokushima University Hospital approved protocol for this study. Sixteen patients with AA (more than 5 cm in diameter, scheduled open surgery) were divided into two groups; one is PPAR-γ agonist administrating group [Formula: see text] n = 6, group P[Formula: see text], and another is the without group [Formula: see text] n = 10, group C[Formula: see text]. PPAR-γ agonist, whose dose was 15 mg/day, was administrated in the group P for more than 2 months before aneurysectomy and grafting (mean; 4.2 ± 3.4 months) (Supplemental Table 1). Biopsy specimens were obtained from abdominal subcutaneous fat, greater omentum, retroperitoneal periaortic fat and aneurysmal wall in surgical procedure. Blood examination also achieved before/after procedure. Harvested specimens were analyzed with histology (HE and EVG), immunohistochemistry (macrophage) and RT-PCR (adiponectin, MCP-1, TNF-α, CD68, matrix metalloprotease (MMP)-2, MMP-9). RESULTS: Macrophage infiltration in aortic wall and retroperitoneal periaortic fat among group P was significantly decreased compared to that among group C. Adiponectin expressions in both subcutaneous fat and retroperitoneal periaortic fat among the group P (adiponectin/ß-actin) were significantly increased compared to those among the group C [subcutaneous fat; 16.8 ± 13.9 vs. 5.82 ± 2.94 (P = 0.04), retroperitoneal periaortic fat; 21.3 ± 24.1 vs. 2.12 ± 1.69 (P = 0.04)]. On the other hand, expressions of TNF-α, and MMP-9 in both aortic aneurysmal wall and retroperitoneal periaortic fat among group P were significantly decreased. [(Aortic aneurysmal wall; TNF-α; 0.45 ± 0.15 vs. 5.18 ± 3.49 (P = 0.02), MMP-9; 39.6 ± 69.0 vs. 721 ± 741 (P = 0.04)], [retroperitoneal periaortic fat; TNF-α; 1.14 ± 0.36 vs. 26.4 ± 25.0 (P = 0.048), MMP-9; 0.18 ± 0.21 vs. 50.0 ± 41.8 (P = 0.047)]. CONCLUSION: These data may indicate that PPAR-γ agonist become the way for preventing or delaying aortic aneurysm progression in patients. More studies will be needed to clarify this drug effects in detail.

Structure and properties of binder gels formed in the system Mg(OH)2-SiO2-H2O for immobilisation of Magnox sludge.

A cementitious system for the immobilisation of magnesium rich Magnox sludge was produced by blending an Mg(OH)2 slurry with silica fume and an inorganic phosphate dispersant. The Mg(OH)2 was fully consumed after 28 days of curing, producing a disordered magnesium silicate hydrate (M-S-H) with cementitious properties. The structural characterisation of this M-S-H phase by (29)Si and (25)Mg MAS NMR showed clearly that it has strong nanostructural similarities to a disordered form of lizardite, and does not take on the talc-like structure as has been proposed in the past for M-S-H gels. The addition of sodium hexametaphosphate (NaPO3)6 as a dispersant enabled the material to be produced at a much lower water/solids ratio, while still maintaining the fluidity which is essential in practical applications, and producing a solid monolith. Significant retardation of M-S-H formation was observed with larger additions of phosphate, however the use of 1 wt% (NaPO3)6 was beneficial in increasing fluidity without a deleterious effect on M-S-H formation. This work has demonstrated the feasibility of using M-S-H as binder to structurally immobilise Magnox sludge, enabling the conversion of a waste into a cementitious binder with potentially very high waste loadings, and providing the first detailed nanostructural description of the material thus formed.

Efficacy and Optimal Timing of Endovascular Treatment for Type B Aortic Dissection.

OBJECTIVES: To determine the efficacy and the optimal timing of thoracic endovascular aortic repair (TEVAR) for closing the primary entry in uncomplicated patients with chronic type B aortic dissection and a patent false lumen (FL). METHODS: Thirteen patients underwent TEVAR for aortic dissection between 2008 and 2012. These patients had chronic dissection with a patent FL and expansion of the aorta. Early TEVAR was performed for five patients within 1-7 months from the index dissection (TEVAR-EC group) and delayed TEVAR was performed for eight patients within 1-16 years (TEVAR-DC group). Changes in the diameters and volumes of the true lumen (TL) and FL and the aortic remodeling were assessed by multidetector computed tomography for 3 years after TEVAR. RESULTS: The reduction rate of FL in the thoracic aorta was notably higher in the TEVAR-EC group than in the TEVAR-DC group regardless of the presence or absence of distal retrograde flow. There was a significant TL expansion despite different timings of TEVAR. CONCLUSIONS: Early TEVAR resulted in good prognosis and preferable aortic remodeling in uncomplicated patients with chronic type B aortic dissection and a patent FL, and we recommend early TEVAR within seven months after the index dissection.

[Reconstruction of pulmonary blood flow in the Norwood procedure; Blalock-Taussig shunt; from bench to surgery].

Although the right-ventricle to pulmonary artery( RV-PA) shunt as a source of pulmonary blood supply of Norwood procedure has improved early outcomes, disadvantages including right ventricular dysfunction or arrhythmias have been reported. So it has been still remained controversial whether BT shunt or RV-PA conduit should be selected. We examined the influence of Blalock-Taussig( BT) shunt size on regulation of the pulmonary blood flow in experimental model of a univentricular heart to determine the specific guidelines regarding suitable shunt size in the Norwood procedure. The canine univentricular heart model with the ratio of shunt size to body weight (SS/BW) of 0.8 to 1.1 showed significant negative correlation between the pulmonary/systemic blood flow ratio( Qp/Qs)and arterial PCo2, but those with SS/BW of 1.1 to 1.4 did not. Similar phenomena were shown with the grouped data on relationship between the Qp/Qs and inspired oxygen fraction. These findings imply that when SS/BW is 0.8 to 1.1, the Qp/Qs is controllable by physiologic respiratory manipulations. In the context of our clinical experiences, SS/BW of 0.9 to 1.0 is considered a useful index for suitable BT shunt in the Norwood procedure.

Iliac access conduit facilitates endovascular aortic aneurysm repair and ipsilateral iliofemoral bypass.

It may be difficult to access a route to deliver a stent-graft for abdominal aortic aneurysm in high-risk patients with bilateral iliofemoral occlusive disease. These two patients underwent both endovascular aortic aneurysm repair by a modified iliac access conduit technique and sequential ipsilateral iliofemoral artery bypass using the conduit, which provided excellent results. The iliac access conduit facilitates endovascular aortic aneurysm repair and ipsilateral iliofemoral bypass of high-risk patients with abdominal aortic aneurysm and bilateral iliofemoral occlusive disease.

Role of macrophage-derived hypoxia-inducible factor (HIF)-1α as a mediator of vascular remodelling.

AIMS: Excessive vascular remodelling leads to progression of a wide range of vasculopathies, and the immune response to intimal injuries is crucial in this process. This vascular remodelling occurs in the hypoxic microenvironment and is closely related to the immune system. Macrophages play a key role in immunological-cell-mediated arterial remodelling. In this study, we clarified the role of macrophage-derived hypoxia-inducible factor (HIF-1α) in vascular remodelling. METHODS AND RESULTS: Wire-induced femoral arterial injury was inflicted in mice lacking the macrophage-specific HIF-1α gene and in their wild-type counterparts. The mutant mice showed both suppressed wire-induced neointimal thickening and decreased infiltration of inflammatory cells in the adventitia, compared with wild-type mice. Studies to clarify the mechanism of restrained vascular remodelling in the mutant mice revealed decreased production of pro-inflammatory cytokines by the activated macrophages and suppressed macrophage migration activity in the mutant mice. Gene expressions of the HIF-1α-deficient macrophages positively correlated with the phenotypic profile of M2 macrophages and negatively correlated with that of M1 macrophages. CONCLUSION: Our results show that HIF-1α in macrophages plays a crucial role in promoting vascular inflammation and remodelling. As decreasing HIF-1α activity in macrophages may prevent the progression of vascular remodelling, HIF-1α may be a possible therapeutic target in vascular diseases.