•Synthetic conditions for obtaining a vaterite single phase by liquid phase reaction were clarified.•Amorphous calcium carbonate (ACC) was formed promptly after the reaction.•The pH during ...crystallization of ACC was involved in the formation of vaterite.•When the pH was 9.7 or less, a single phase of vaterite was obtained.•At the pH of 9.7, the abundance ratio of HCO3− ion was 80% or more.
This paper reports on the effect of pH on polymorphism of calcium carbonate (vaterite) formed in the CaCl2-Na2CO3-H2O reaction system. The initial pH of CaCl2 aqueous solution was adjusted to the initial pH 2.0–11.3 using HCl and NH3 aqueous solution. The initial pH was 6.5 without pH adjustment. When the reaction was carried out, amorphous calcium carbonate (ACC) was formed at the early stage of the reaction and crystallized to calcite and vatrite after 3 min of stirring. Formation ratio of vaterite at this time was 60％. Single-phase vaterite was formed at initial pH 2.0–2.5. Further, focusing on the pH during ACC crystallization. When HCO3− ions were 80% or more during ACC crystallization, single-phase vaterite was formed.
We studied the influence of swelling agents on pore size distributions in the shell of porous silica-alumina hollow sphere particles for acid-promoted hydrolytic generation of hydrogen from ammonia ...borane. Their well-ordered porous shells were formed with micelle templates of cetyltrimethylammonium bromide on spherical polystyrene (PS) particle templates, and swelling agents were introduced into the micelle templates for expanding the pores. Non-polar agents (hexane and toluene) did not significantly influence the size of the pores, whereas, polar agents (1-dodecanol and 1-dodecylamine) effectively expanded the pores. The hollow sphere particles formed with 1-dodecylamine possessed narrow pore distribution with a high peak pore volume. The activity of the hollow sphere particles in the hydrolytic generation of hydrogen increased according to increasing pore size with a narrow distribution, and the hollow sphere particles formed with 1-dodecylamine showed an approximately five times higher TOF for the hydrogen evolution than those formed without a swelling agent.
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•Swelling agents have effect of controlling pores of silica-alumina hollow spheres.•Positively charged 1-dodecylamine expanded pores with well-ordered structure.•The well-ordered hollow spheres promoted hydrogen evolution from ammonia borane.
Zinc silicate (ZS), which occurs naturally as willemite, is primarily used as a ceramic pigment and finds wide applications as a fluorescent material and in nonlinear voltage resistor devices. In ...recent years, ZS has been studied as a coating material for the electrode surfaces of air batteries and as a negative electrode material for Li-ion batteries. In this study, we investigated its suitability as an anode material in aqueous Zn secondary batteries. Conventional ZnO dissolves and precipitates as zincate ions in alkaline electrolytes, leading to dendritic growth and passivation. By utilizing ZS as the anode material, we observed significant improvements in cycle characteristics. Furthermore, substituting a portion of the ZS with P resulted in increased battery capacity and confirmed the reversible dissolution–precipitation reactions of Zn ions during charging and discharging.
The present work has investigated influence of pore structure of silica coated on copper-zinc oxide-based catalyst for hydrogenation of carbon dioxide into methanol. For controlling the pore ...structure, micelles of a cationic surfactant, cethyltrimethylammonium bromide (CTAB), was used without and with a swelling agent, 1-dodecylamine, during coating silica on the commercial copper–zinc oxide-based catalyst. The pore structure depended on the amount of the surfactant and the swelling agent, and the specific surface area and the ratio of mesopores of the silica-coated catalyst significantly increased with adding 1-dodecylamine with the surfactant. The silica-coated catalyst prepared both with CTAB and 1-dodecylamine showed the significantly rapid evaporation of physisorbed water on the catalysts, and the property can reflect the catalyst’s high activity and stability for hydrogenation of carbon dioxide into methanol.
Chelate-setting calcium-phosphate cements (CPCs) have been developed using inositol phosphate (IP6) as a chelating agent. However, the compressive strength of the CPC fabricated from a commercially ...available hydroxyapatite (HAp) powder was approximately 10 MPa. In this study, we miniaturized HAp particles as a starting powder to improve the compressive strength of chelate-setting CPCs and examined the adsorption properties of IP6 onto HAp powders. An HAp powder with a specific surface area (SSA) higher than 200 m
/g (HApHS) was obtained by ultrasonic irradiation for 1 min in a wet synthesis process, greatly improving the SSA (214 m
/g) of the commercial powder without ultrasonic irradiation. The HApHS powder was found to be a B-type carbonate-containing HAp in which the phosphate groups in apatite were replaced by carbonate groups. Owing to the high SSA, the HApHS powder also showed high IP6 adsorption capacity. The adsorption phenomena of IP6 to our HApHS and commercially available Hap powders were found to follow the Freundlich and Langmuir models, respectively. We found that IP6 adsorbs on the HApHS powder by both physisorption and chemisorption. The fine HapHS powder with a high SSA is a novel raw powder material, expected to improve the compressive strength of chelate-setting CPCs.
Background
This retrospective multicenter study aimed to evaluate the survival benefit of upfront cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (RCC) patients stratified by ...International Metastatic RCC Database Consortium (IMDC) risk criteria.
Methods
We reviewed the medical records in the Michinoku Database between 2008 and 2019. Patients who received upfront CN, systemic therapy without CN (no CN) and CN after drug therapy (deferred CN) were analyzed. To exclude selection bias due to patient characteristics, baseline clinical data were adjusted by inverse probability of treatment weighting (IPTW). Overall survival (OS) was compared between upfront CN and non-upfront CN (no CN plus deferred CN). Associations between time-varying covariates including systemic therapies and OS stratified by IMDC risk criteria were analyzed by IPTW-adjusted Cox regression method.
Results
Of 259 patients who fulfilled the selection criteria, 107 were classified in upfront CN and 152 in non-upfront CN group. After IPTW-adjusted analysis, upfront CN showed survival benefit compared to non-upfront CN in patients with IMDC intermediate risk (median OS: 52.5 versus 31.3 months,
p
< 0.01) and in patients with IMDC poor risk (27.2 versus 11.4 months,
p
< 0.01). In IPTW-adjusted Cox regression analysis of time-varying covariates, upfront CN was independently associated with OS benefit in patients with IMDC intermediate risk (hazard ratio 0.52, 95% confidence interval 0.29–0.93,
p
= 0.03) and in patients with IMDC poor risk (0.26, 0.11–0.59,
p
< 0.01).
Conclusions
Upfront CN may confer survival benefit in RCC patients with IMDC intermediate and poor risk.
The present work investigated the thermochemical properties of urea synthesized in well-ordered nanospaces of porous hollow silica spheres’ shells from recovered ammonia and carbon dioxide in aqueous ...solution. Thermochemical behaviors of the urea synthesized in well-ordered nanospaces of the hollow spheres’ shells prepared with 1-dodeclyamine were analyzed from the results of thermogravimetric analysis (TGA) and differential thermal analysis (DTA), and endothermic peaks assigned as the phase transition and decomposition were observed at ca. 440 and 514 K, respectively, which were higher than those of pristine urea (405 and 408 K, respectively), probably because of the nanoconfinement effect. The decomposition behavior was also confirmed by the result of diffuse reflectance infrared Fourier transform (DRIFT) spectra of the samples treated at various temperatures up to 573 K, and the decomposition of urea synthesized in the well-ordered nanospaces of the hollow spheres’ shells started at 468 K and completed up to 533 K.
The present article is the abbreviated English translation of the Japanese guidelines for male lower urinary tract symptoms and benign prostatic hyperplasia updated as of the end of 2016. The target ...patients are men aged >50 years complaining of lower urinary tract symptoms, with or without benign prostatic hyperplasia, and the target readers are non‐urological general physicians and urologists. Mandatory assessment for general physicians is medical history, physical examination, urinalysis and measurement of serum prostate‐specific antigen. Additional mandatory assessment for urologists is symptoms and quality of life assessment by questionnaires, uroflowmetry, residual urine measurement, and prostate ultrasonography. Nocturia requires special attention, as it can result from nocturnal polyuria and/or sleep disturbance rather than lower urinary tract disorders. Functional lower urinary tract disorders with or without benign prostatic hyperplasia are primarily managed by conservative therapy and medications, such as α1‐blockers and phosphodiesterase‐type 5 inhibitors. Use of other medications or combination pharmacotherapy is to be reserved for urologists. 5α‐Reductase inhibitors and anticholinergics or β3 agonists are indicated for men with enlarged prostates and overactive bladder symptoms, respectively. Surgical intervention for bladder outlet obstruction is considered for persistent symptoms or benign prostatic hyperplasia‐related comorbidities. Surgical modalities should be optimized by the patient's characteristics, performance of equipment and the surgeon's experience.
The Railway Technical Research Institute has been researching a variety of technologies related to railway structures. These include technologies for maintenance (inspection, diagnosis, prediction, ...repair, renewal), earthquake countermeasures, construction and environmental impact assessment. This review gives some overview of recent research and development trends in maintenance and construction technologies for "geotechnical structures" (earth retaining walls, soil structures and tunnels) conducted at the Railway Technical Research Institute.
We developed herein photoluminescent glass ceramics based on rare-earth ion-doped Na5YSi4O12-type materials according to the Na3+3xY1−x−yRySi3O9 (R: Sm3+, Eu3+, Dy3+, Tb3+) composition. Glass ...ceramics generally have the advantages of excellent chemical durability, heat resistance, and moldability over sintered ceramics. Upon irradiation with near-ultraviolet light, Sm3+-, Eu3+-, Dy3+-, and Tb3+-doped glass ceramics emit purplish orange, reddish orange, yellow, and green lights, respectively. The photoluminescent emission intensity of glass ceramics is higher than that of the original glasses, and the emission intensity depends on the crystalline phase. The highest emission intensity of various rare-earth ion-doped glass ceramics is obtained when the parameter y is equal to 0.03, 0.16, and 0.02 for the Sm3+-, Eu3+-, and Dy3+-doped glass ceramic samples, respectively. The internal quantum efficiency is 3%, 37%, 7% and 23% for the Sm3+-, Eu3+-, Dy3+-, and Tb3+-doped samples, respectively. Thus the Na superionic conducting Na5YSi4O12-type glass-ceramics were proved to have potentiality as novel phosphors.
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