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1.
Surg Today ; 54(7): 801-806, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38110619

RESUMEN

PURPOSE: Some prospective trials have demonstrated the feasibility of sentinel node (SN) biopsy in gastric cancer (GC) surgery. This study aimed to identify the appropriate concentration settings for the intraoperative injection of indocyanine green (ICG) for SN biopsy. METHODS: Before the clinical studies, porcine model experiments explored the optimal concentration of ICG injected intraoperatively. Next, nine GC patients were enrolled in the clinical research. ICG (0.5 ml) was injected intraoperatively into four quadrants of the submucosa around the tumor at various concentrations (0.5, 0.25, and 0.1 mg/ml). The lymphatic basin dissection method was applied to the ICG-positive lymphatic areas. The number and location of the lymphatic basins and positive nodes were recorded intraoperatively. RESULTS: In the porcine model, the visibility gradually became clear at an ICG concentration higher than 0.1 mg/ml. In the clinical study, the average number of detected lymphatic basins was 3.3, 1.7, and 1.7, respectively. The mean number of detected SNs was 14.7, 6.7, and 4.0, respectively. CONCLUSION: To improve the reproducibility of SN biopsy, it is essential to prepare the correct concentration setting of ICG. Under current conditions in which ICG is injected intraoperatively, a 0.1 mg/ml concentration setting of ICG may be necessary and sufficient for SN identification.


Asunto(s)
Verde de Indocianina , Cuidados Intraoperatorios , Imagen Óptica , Biopsia del Ganglio Linfático Centinela , Ganglio Linfático Centinela , Neoplasias Gástricas , Verde de Indocianina/administración & dosificación , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Humanos , Proyectos Piloto , Animales , Biopsia del Ganglio Linfático Centinela/métodos , Masculino , Femenino , Ganglio Linfático Centinela/patología , Ganglio Linfático Centinela/diagnóstico por imagen , Cuidados Intraoperatorios/métodos , Anciano , Persona de Mediana Edad , Porcinos , Imagen Óptica/métodos , Periodo Intraoperatorio , Colorantes/administración & dosificación , Reproducibilidad de los Resultados , Estudios de Factibilidad , Metástasis Linfática
2.
J Oral Implantol ; 49(4): 382-387, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-36796076

RESUMEN

Oral reconstruction in fully edentulous patients can be challenging at times. Hence, it is important to offer the most suitable treatment option after a detailed clinical examination and treatment plan. This 14-year long-term follow-up report is the clinical case of a 71-year-old nonsmoker who visited the clinic in 2006 and opted for full-mouth reconstruction using Auro Galvano crown (AGC) attachments. Maintenance was performed twice a year for the past 14 years, and the clinical results were satisfactory, with no signs of inflammation or lack of retention of the superstructures. This was associated with a high level of patient satisfaction, as indicated by the Oral Health Impact Profile. Compared to the screw-retained implants over dentures, AGC attachments can be a viable and effective treatment option when restoring fully edentulous arches.


Asunto(s)
Implantes Dentales , Arcada Edéntula , Boca Edéntula , Humanos , Anciano de 80 o más Años , Anciano , Arcada Edéntula/cirugía , Implantación Dental Endoósea/métodos , Resultado del Tratamiento , Boca Edéntula/cirugía , Prótesis Dental de Soporte Implantado/métodos , Estudios de Seguimiento
3.
Environ Sci Technol ; 51(23): 13886-13894, 2017 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-29135229

RESUMEN

The reversibility of cesium adsorption in contaminated soil is largely dependent on its interaction with micaceous minerals, which may be greatly influenced by various cations. Herein, we systematically investigated the effects of NH4+, K+, Mg2+, and Ca2+ on the adsorption/desorption of Cs+ into different binding sites of vermiculitized biotite (VB). Original VB was initially saturated by NH4+, K+, or Mg2+; we then evaluated the adsorption of Cs+ on three treated VBs, and the desorption by extraction with NH4+, K+, Mg2+, or Ca2+ was further evaluated. Our structural analysis and Cs+ extractability determinations showed that NH4+ and K+ both collapsed the interlayers of VB, resulting in the dominant adsorption of Cs+ to external surface sites on which Cs+ was readily extracted by NH4+, K+, Mg2+, or Ca2+ irrespective of their species, whereas Mg2+ maintained the VB with expanded interlayers, leading to the overwhelming adsorption of Cs+ in collapsed interlayer sites on which the Cs+ desorption was difficult and varied significantly by the cations used in extraction. The order of Cs+ extraction ability from the collapsed interlayers was K+ ≫ Mg2+ ≈ Ca2+ ≫ NH4+. These results could provide important insights into Cs migration in soil and its decontamination for soil remediation.


Asunto(s)
Silicatos de Aluminio , Cesio , Compuestos Ferrosos , Adsorción , Sitios de Unión
4.
Implant Dent ; 25(3): 361-6, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26889624

RESUMEN

PURPOSE: To investigate the causes for internal implant fractures, which is suggested to be one of the reasons for marginal bone loss. MATERIALS AND METHODS: From a 14-year database of 6051 implants, 10 single implant vertical fractures were identified and the abutments were all castable abutments. The abutments presented contamination and irregularities at the internal connecting areas. The hypothesis was that perfect fit was disturbed by laboratory polishing procedures, and finite element analysis (FEA) using overcorrected and undercorrected castable abutment models were created and tested against a perfect fit model. RESULTS: The results from the FEA presented that both overcorrected and undercorrected models presented nonuniform excessive plastic strain distribution in the neck portion of the implants where clinically an implant fracture was noted. CONCLUSIONS: The results suggested that laboratory procedures could induce plastic strain of the implant-abutment complex, which increases the risk of fracture.


Asunto(s)
Implantes Dentales/efectos adversos , Pilares Dentales/efectos adversos , Diseño de Implante Dental-Pilar , Fracaso de la Restauración Dental , Análisis del Estrés Dental , Análisis de Elementos Finitos , Humanos
5.
Anal Sci ; 40(2): 335-339, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37934340

RESUMEN

We connected three research fields on Ru extraction, XANES, and DFT calculation and elucidate the sequence of distribution ratio (D) and their reactions. The magnitude order of the distribution ratio, D(Ru), from acids, HCl > H2SO4 > HNO3 > HClO4, by IDOA indicates to extract readily the stable Ru-Cl ions. The XANES signals, which suggests the electrical charge of Ru(III) extracted into the organic phase, supports the ion-pairing extraction of the anionic Ru-Cl complex with an extractant protonated. Ru(III) in other acids might be extracted by solvation of extractant, thus ion-pair extraction is stronger than solvation in Ru extraction. According to the D(Ru), the same extractant trend, NTAamide > MIDOA > IDOA, as the energy gap of HOMO and LUMO by DFT calculation is found, which suggests that DFT calculation can give the relative magnitude of each D(M) value when extractant and metal in an extraction are determined.

6.
Anticancer Res ; 44(2): 823-828, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38307575

RESUMEN

BACKGROUND/AIM: The Japan Society of Endoscopic Surgery (JSES) proctoring system was established to prevent serious pancreatic pressure injuries in Japan in 2019. To safely perform robotic gastrectomy (RG) in our hospital, which has no experience in robotic surgery, we conducted a clinical trial with the support of this proctoring system. PATIENTS AND METHODS: The present study was a single-center clinical prospective study. The primary endpoint was morbidity determined using Clavien-Dindo classification (C-D) Grade IIIa or higher. RESULTS: Ten patients, seven males and three females, were recruited in this study. RG was performed under the proctoring system of the JSES in the initial six cases and was completed independently for the remaining four patients. We successfully performed the initial ten cases without C-D classification grade IIIa or higher morbidities. CONCLUSION: This study underscores the significance of a proctoring system for introducing RG to facilities with limited experience in robotic surgery. Despite some limitations, this study demonstrated successful outcomes in the initial ten cases, emphasizing the benefits for both surgeons and patients. This study provides valuable insights into the safety of RG in small institutions and calls for further research in this area.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Robótica , Neoplasias Gástricas , Femenino , Humanos , Masculino , Gastrectomía/efectos adversos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Estudios Prospectivos , Estudios Retrospectivos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Neoplasias Gástricas/cirugía , Resultado del Tratamiento
7.
Anticancer Res ; 44(6): 2717-2724, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38821621

RESUMEN

BACKGROUND/AIM: The purpose of this study was to evaluate the outcomes of the sentinel node navigation surgery (SNNS) followed by limited gastrectomy for early gastric cancer (EGC) with Endoscopic Curability C-2 (eCuraC-2). PATIENTS AND METHODS: Between 2001 and 2018, 33 patients were included in this study. Following sentinel node (SN) biopsy using indocyanine green combined with an infrared ray laparoscopic system, limited gastrectomy (LG) [wedge resection (WR), or segmental gastrectomy (SG)] was performed without extended lymphadenectomy. RESULTS: SN detection rate was 97% (32/33). The mean number of SNs per case was 7.8. Three patients (9.1%) with lymph node metastasis (LNM) had a positive SN identified by intraoperative pathological examination. When intraoperative pathologic examination showed SN to be LNM negative, 11 patients underwent WR, and seven were subjected to SG. Postoperative pathological examinations showed no false negatives for LNM, and four patients (12%) had residual cancer in their resected stomachs. Overall survival and disease-specific survival five years after SNNS were 87.9% and 100%, respectively. CONCLUSION: SNNS followed by LG with lymphatic basin resection may be one of the ideal procedures for patients with eCuraC-2 due to the accurate diagnosis of LNM and favorable disease-specific prognosis.


Asunto(s)
Gastrectomía , Biopsia del Ganglio Linfático Centinela , Ganglio Linfático Centinela , Neoplasias Gástricas , Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Estudios Retrospectivos , Gastrectomía/métodos , Biopsia del Ganglio Linfático Centinela/métodos , Ganglio Linfático Centinela/patología , Ganglio Linfático Centinela/cirugía , Metástasis Linfática , Adulto , Escisión del Ganglio Linfático/métodos , Anciano de 80 o más Años
8.
Clin Oral Implants Res ; 24 Suppl A100: 134-8, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22220565

RESUMEN

OBJECTIVES: This study utilized the constitution and expression of Runx2/Cbfa1 to conduct 6-month-post-operation histomorphometrical and histochemical analysis of osteocalcin in bone regeneration following sinus-floor augmentation procedures using ß-tricalcium phosphate (ß-TCP) and autogenous cortical bone. MATERIAL AND METHODS: Thirteen sinuses of nine patients were treated with sinus-floor augmentation using 50% ß-TCP and 50% autogenous cancellous bone harvested from the ramus of the mandible. Biopsies of augmented sinuses were taken at 6 months for histomorphometric and immunohistochemical measurements. RESULTS: Runx2/Cbfa1- and osteocalcin-positive cells were found around TCP particles and on the bone surface. Approximately 60% of cells found around TCP particles stained positive for Runx2/Cbfa1. Fewer cells stained positive for osteocalcin. These positive cells decreased apically with increasing vertical distance from the maxillary bone surface. Histomorphometric analysis showed that the augmented site close to residual bone and periosteum contained approximately 42% bony tissue and 42% soft connective tissue, and the remaining 16% consisted of TCP particles. On the other hand, the augmented bone far from residual bone and periosteum contained 35% bony tissue and 50% soft connective tissue. CONCLUSIONS: Our data suggest that TCP particles attract osteoprogenitor cells that migrate into the interconnecting micropores of the bone-substitute material by 6 months. The augmented site close to residual bone contained a higher proportion of bony tissue and a lower proportion of soft connective tissue than did the augmented site far from residual bone.


Asunto(s)
Fosfatos de Calcio/uso terapéutico , Implantación Dental Endoósea , Implantes Dentales , Seno Maxilar/cirugía , Elevación del Piso del Seno Maxilar/métodos , Biopsia , Regeneración Ósea , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Humanos , Inmunohistoquímica , Osteocalcina/metabolismo , Tomografía Computarizada por Rayos X
9.
Surg Case Rep ; 9(1): 139, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37548808

RESUMEN

BACKGROUND: Trastuzumab-based chemotherapy is a standard treatment regimen for human epithelial growth factor 2 (HER2)-positive gastric cancer. This is a case of a patient who has survived 12 years after being diagnosed with advanced gastric cancer with multiple liver and lung metastases. CASE PRESENTATION: A woman in her 70s underwent total gastrectomy, cholecystectomy, and left hepatic lobectomy for gastric cancer with liver metastasis. One month after the surgery, multiple liver metastases appeared. After two courses of S-1 + CDDP chemotherapy, the liver metastases disappeared, and new lung metastases occurred. Because the primary tumor was HER2 positive, S-1 + CDDP + trastuzumab chemotherapy was performed. After one course of chemotherapy, the blood test showed pancytopenia, and CDDP was discontinued. S-1 + trastuzumab chemotherapy was then initiated, and as a result, the lung metastases disappeared. The patient is alive without recurrence 12 years after the surgery. CONCLUSIONS: We encountered a case of long-term survival after multidisciplinary treatments for HER2-positive advanced gastric cancer with multiple liver and lung metastases.

10.
Opt Express ; 20(19): 21739-48, 2012 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-23037293

RESUMEN

We analyzed the output power characteristics of a cryogenically cooled Yb:YAG total-reflection active-mirror (TRAM) laser oscillator including the temperature dependence of the emission cross section and the reabsorption loss of the Yb:YAG TRAM. A CW multi-transverse mode oscillation of a 9.8 at.% doped 0.6 mm thick Yb:YAG ceramic TRAM was investigated for various pump spot sizes and compared with theoretical results. The Yb:YAG temperatures were inferred from the ratio between fluorescence intensities at 1022 nm and 1027 nm which varied significantly with temperature below 200 K. Output power calculations using evaluated temperatures were in good agreement with the experimental data measured between 77 and 200 K, and the output power suppression due to the temperature rise observed above ~140 K. To the best of our knowledge, this is the first evaluation of output power for a cryogenically cooled Yb:YAG TRAM laser.

11.
Sci Rep ; 12(1): 5135, 2022 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-35332191

RESUMEN

We have examined the uptake mechanisms of platinum-group-metals (PGMs) and molybdenum (Mo) ions into Prussian blue nanoparticles (PBNPs) in a nitric acid solution for 24-h sorption test, using inductively coupled plasma atomic emission spectroscopy, powder XRD, and UV-Vis-NIR spectroscopy in combination with first-principles calculations, and revealed that the Ru4+ and Pd2+ ions are incorporated into PBNPs by substitution with Fe3+ and Fe2+ ions of the PB framework, respectively, whereas the Rh3+ ion is incorporated into PBNPs by substitution mainly with Fe3+ and minorly with Fe2+ ion, and Mo6+ ion is incorporated into PBNPs by substitution with both Fe2+ and Fe3+ ions, with maintaining the crystal structure before and after the sorption test. Assuming that the amount of Fe elusion is equal to that of PGMs/Mo substitution, the substitution efficiency is estimated to be 39.0% for Ru, 47.8% for Rh, 87% for Pd, and 17.1% for Mo6+. This implies that 0.13 g of Ru, 0.16 g of Rh, 0.30 g of Pd, and 0.107 g of Mo can be recovered by using 1 g PBNPs with a chemical form of KFe(III)[Fe(II)(CN)6].

12.
Artículo en Inglés | MEDLINE | ID: mdl-35353090

RESUMEN

Implant therapy for tooth loss in the molar area is challenging due to the anatomical limitations, requiring bone augmentation procedures that are associated with high surgical complexity and long postsurgical recovery. Recently, many studies have demonstrated the usefulness of short implants. However, few studies have been performed in Japanese patients to evaluate peri-implant bone changes, changes in peri-implant epithelial tissue, and patient satisfaction. The present study included 16 patients (5 men, 11 women; mean age: 60 years) who received 26 short (6-mm) implants. Changes in peri-implant bone and epithelial tissue were measured radiographically at superstructure loading and after 2 years. Peri-implant pocket probing depth was measured at the epithelial tissue and compared at both time points. Patient satisfaction was graded using the Oral Health Impact Profile (OHIP-14) before treatment and at follow-up. The mean mesial and distal bone levels were -0.05 mm and 0.37 mm at loading, respectively, and were 0.33 mm and 0.53 mm after 2 years, respectively. Significant peri-implant bone formation for mesial and distal bone levels at both time points were determined by Wilcoxon signed-rank test. Mean probing depth increased slightly, from 3.03 mm at loading to 3.33 mm after 2 years, but no significant difference was found. The OHIP-14 found that patient satisfaction levels increased after 2 years. Using 6-mm short implants in sites with insufficient bone levels can be a highly beneficial treatment option for patients, as it avoids the need for bone augmentation. However, more long-term and detailed studies on the clinical outcomes for these implants are required.


Asunto(s)
Implantes Dentales , Satisfacción del Paciente , Implantación Dental Endoósea , Diseño de Prótesis Dental , Femenino , Estudios de Seguimiento , Humanos , Japón , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
13.
Opt Express ; 19(3): 2448-55, 2011 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-21369064

RESUMEN

We report on a novel amplifier configuration concept for a 10 kW laser system using a zig-zag optical path based on a cryogenic Yb:YAG Total-Reflection Active-Mirror (TRAM) laser. The laser material is a compact composite ceramic, in which three Yb:YAG TRAMs are combined in series to increase the output power. Output powers of up to 214 W with a slope efficiency of 63% have been demonstrated for CW operation, even at a quite low pump intensity of less than 170 W/cm2. Further scaling could achieve output powers of more than 10 kW.


Asunto(s)
Amplificadores Electrónicos , Cerámica/química , Rayos Láser , Lentes , Frío , Diseño de Equipo , Análisis de Falla de Equipo
14.
RSC Adv ; 11(34): 20701-20707, 2021 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-35479358

RESUMEN

We have investigated the uptake mechanism of palladium (Pd: one of the most important elements in industry used as a catalyst) ions into Prussian-blue nanoparticles (PBNPs) in a nitric acid solution via high-resolution electron transmission microscopy, inductively coupled plasma atomic emission spectroscopy, powder X-ray diffraction, and ultraviolet-visible-near infrared spectroscopy in combination with first principles calculations. Comparison of the structural and electronic properties of PBNPs between before and after a 24 h sorption test reveals that the Pd2+ ions incorporated into PBNPs by the substitution of Fe2+ ions of the PB framework while maintaining the crystal structure, and the substitution efficiency is estimated to be 87% per PB unit cell. This implies that 0.30 g of Pd can be recovered by using 1 g of PB having the chemical formula KFe(iii)[Fe(ii)(CN)6]. The present finding suggests that PB (or its analogues) can be applied to recycle noble and rare metals from electronic and nuclear wastes.

15.
Water Res ; 177: 115804, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32302807

RESUMEN

The adsorption and desorption of cesium (Cs) on clays of contaminated soil in a rhizosphere zone can be greatly affected by various biogeochemical processes, the timespans of which are usually months to years. Herein, we present several representative scenarios of the binding of Cs on diverse sites of vermiculitized biotite by controlled Cs adsorption to particles of different sizes. We investigated whether and how the fixed Cs in the different scenarios is desorbed by ambient and hydrothermal treatments with several low-molecular-weight organic acids (LMWOAs). The results showed that the sorbed Cs was discriminatively retained in the un-collapsed, partially collapsed, and thoroughly collapsed structures of vermiculites. The desorption of the sorbed Cs by hydrothermal LMWOAs extractions was easily realized in the un-collapsed structure, but was limited or minimal in the partially collapsed and thoroughly collapsed structures. The Cs desorption varied in accord with the LMWOA species applied and increased with the acid concentration, temperature, and number of treating cycles. The analysis of Cs-desorbed specimens confirmed their partial destruction and interlayer expansion, suggesting that the underlying mechanism of Cs removal by LMWOAs involves not only acid dissolution and complexation but also the accelerated weathering of clays within a short time under hydrothermal conditions. Our findings contribute novel insights into the mobility, bioavailability, and fate of Cs in contaminated soils and its removal from these soils for environmental restorations.


Asunto(s)
Arcilla , Suelo , Adsorción , Cesio , Radioisótopos de Cesio , Descontaminación , Minerales
16.
Anal Sci ; 36(2): 241-245, 2020 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-31564678

RESUMEN

To investigate the effective separation of actinides (Ans) from lanthanides (Lns), single-stage batch extraction experiments were performed with a novel extractant, tetradodecyl-1,10-phenanthroline-2,9-diamide (TDdPTDA) with various diluents such as 3-nitrobenzotrifluoride (F-3), nitrobenzene, and n-dodecane for Am, Cm, and Lns. The extraction kinetics with TDdPTDA was rapid enough to perform continuous extraction experiments using mixer-settler extractors. The slopes of the distribution ratio versus the TDdPTDA concentration and the distribution ratio versus the nitric acid concentration were similar for F-3 and nitrobenzene systems, but different from the n-dodecane system. These differences were attributed to the characteristics of the diluents. This study revealed high distribution ratios of Am (DAm) and Cm (DCm) for TDdPTDA, with the high separation factors (SFs) of Am from Lns enough for their separation.

17.
J Hazard Mater ; 387: 121677, 2020 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-31784126

RESUMEN

The effective and efficient removal of radioactive Cs from contaminated soil is highly urgent for the nuclear post-accident remediation. In present study, we achieved rapid Cs desorption from both a typical micaceous clay (i.e., vermiculitized biotite, VB) and actually contaminated soil by high-speed ion exchange through temperature-controlled continuous leaching with Mg-solutions in a column reactor. Cs-sorbed VB was firstly employed as a soil surrogate to explore the macro-Cs desorption process and micro-mechanism in detail. Results showed that VB sandwiched the adsorbed Cs to its interlayers within collapsed structure (10.7 Å) and prevent Cs release even by abundant extraction with H2O at 250 °C or Mg2+ at 25 °C. However, Mg2+-extracted Cs desorption boosted significantly with elevating temperatures and 100 % of sorbed-Cs was removed from Cs-VB leached above 150 °C. Further structural and composition analysis of the leached specimen ensured that solvated Mg2+ preferentially entered into Cs+-collapsed interlayers at 150 °C than K+-interlayers above 200 °C, leading to prior complete Cs removal over K from VB at lower temperatures. By contrast, the Cs-contaminated soil reduced by ∼39 % but ∼82 % of its initial radioactivity after equally leaching with same volumes of Mg2+-solution at 150 and 200 °C, respectively. These temperature-controlled Cs desorption validated that radioactive Cs in actual soil indeed be tightly trapped by micaceous clays nearly in the Cs-K co-collapsed interlayers, to which its extraction by other cations can conditionally occur above enough high leaching temperatures. These superior features would inspire new insights for the design of novel practical technologies for treatment and decontamination of the nuclear post-accident soils.

18.
Opt Lett ; 34(21): 3439-41, 2009 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-19881620

RESUMEN

An efficient high-power laser operation has been demonstrated by using a cryogenic Yb:YAG composite ceramic with a total-reflection active-mirror arrangement. The composite ceramic, which had no high-reflection coating and was cooled with liquid nitrogen directly, showed four-level operation even at 67 kW/cm(3) of high pump density. A 273 W cw output power was obtained with 65% optical efficiency and 72% slope efficiency.


Asunto(s)
Cerámica , Frío , Láseres de Estado Sólido , Iterbio
19.
Dalton Trans ; 47(30): 10063-10070, 2018 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-29987285

RESUMEN

A novel hydrophobic ionic liquid including an N,N,N',N'-tetrakis(2-methylpyridyl)-1,2-phenylenediamine-4-amido structure ((IL-1,2-tpbd)+NTf2-) was successfully synthesized. (IL-1,2-tpbd)+NTf2- combined one amido (O-hard donor) and four pyridine (N-soft donor) groups. Its Cd2+ and Zn2+ separation behavior in nitric acid solution was investigated as a function of the extraction time, effect of pH etc. by dissolving (IL-1,2-tpbd)+NTf2- in a room temperature ionic liquid, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ((C6mim)+NTf2-). The extraction kinetics were fairly fast and could reach equilibrium within 4 h. When pHeq ≥ 1.8, the extraction percentage of Cd2+ and Zn2+ remained constant and the maximum separation factor was calculated as 12.78 at pHeq = 3.1; when pHeq < 1.8, the extraction percentage of Cd2+ and Zn2+ decreased drastically due to the protonation of the pyridine groups. Complete stripping of the extracted Cd2+ and Zn2+ from the ionic liquid phase into an aqueous phase was successfully achieved under highly acidic conditions ([HNO3] = 2 M) without adding any other metal complex forming agents. The extraction mechanism was summarized as a cation exchange due to the independence of nitrate ions in the extraction process. Additionally, the results of the slope analysis and UV-vis titration revealed the formation of a 1 : 2 complex. Furthermore, (IL-1,2-tpbd)+NTf2- showed a higher preference for Cd2+ even under the interference of various co-existing metal ions.

20.
J Hazard Mater ; 326: 47-53, 2017 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-27987449

RESUMEN

Adsorption of cesium (Cs) on phyllosilicates has been intensively investigated because natural soils have strong ability of immobilizing Cs within clay minerals resulting in difficulty of decontamination. The objectives of present study are to clarify how Cs fixation on vermiculite is influenced by structure change caused by Cs sorption at different loading levels and how Cs desorption is affected by various replacing cations induced at different treating temperature. As a result, more than 80% of Cs was readily desorbed from vermiculite with loading amount of 2% saturated Cs (5.49×10-3mmolg-1) after four cycles of treatment of 0.01M Mg2+/Ca2+ at room temperature, but less than 20% of Cs was desorbed from saturated vermiculite. These distinct desorption patterns were attributed to inhibition of Cs desorption by interlayer collapse of vermiculite, especially at high Cs loadings. In contrast, elevated temperature significantly facilitated divalent cations to efficiently desorb Cs from collapsed regions. After five cycles of treatment at 250°C with 0.01M Mg2+, ∼100% removal of saturated Cs was achieved. X-ray diffraction analysis results suggested that Cs desorption was completed through enhanced diffusion of Mg2+ cations into collapsed interlayer space under hydrothermal condition resulting in subsequent interlayer decollapse and readily release of Cs+.

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