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1.
Surg Today ; 54(7): 801-806, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38110619

RESUMO

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.


Assuntos
Verde de Indocianina , Cuidados Intraoperatórios , Imagem Óptica , Biópsia de Linfonodo Sentinela , Linfonodo Sentinela , Neoplasias Gástricas , Verde de Indocianina/administração & dosagem , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Humanos , Projetos Piloto , Animais , Biópsia de Linfonodo Sentinela/métodos , Masculino , Feminino , Linfonodo Sentinela/patologia , Linfonodo Sentinela/diagnóstico por imagem , Cuidados Intraoperatórios/métodos , Idoso , Pessoa de Meia-Idade , Suínos , Imagem Óptica/métodos , Período Intraoperatório , Corantes/administração & dosagem , Reprodutibilidade dos Testes , Estudos de Viabilidade , Metástase Linfática
2.
J Oral Implantol ; 49(4): 382-387, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36796076

RESUMO

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.


Assuntos
Implantes Dentários , Arcada Edêntula , Boca Edêntula , Humanos , Idoso de 80 Anos ou mais , Idoso , Arcada Edêntula/cirurgia , Implantação Dentária Endóssea/métodos , Resultado do Tratamento , Boca Edêntula/cirurgia , Prótese Dentária Fixada por Implante/métodos , Seguimentos
3.
Environ Sci Technol ; 51(23): 13886-13894, 2017 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-29135229

RESUMO

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.


Assuntos
Silicatos de Alumínio , Césio , Compostos Ferrosos , Adsorção , Sítios de Ligação
4.
Implant Dent ; 25(3): 361-6, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26889624

RESUMO

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.


Assuntos
Implantes Dentários/efeitos adversos , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô , Falha de Restauração Dentária , Análise do Estresse Dentário , Análise de Elementos Finitos , Humanos
5.
Anal Sci ; 40(2): 335-339, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37934340

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-38307575

RESUMO

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.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Neoplasias Gástricas , Feminino , Humanos , Masculino , Gastrectomia/efeitos adversos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Neoplasias Gástricas/cirurgia , Resultado do Tratamento
7.
Anticancer Res ; 44(6): 2717-2724, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38821621

RESUMO

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.


Assuntos
Gastrectomia , Biópsia de Linfonodo Sentinela , Linfonodo Sentinela , Neoplasias Gástricas , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Estudos Retrospectivos , Gastrectomia/métodos , Biópsia de Linfonodo Sentinela/métodos , Linfonodo Sentinela/patologia , Linfonodo Sentinela/cirurgia , Metástase Linfática , Adulto , Excisão de Linfonodo/métodos , Idoso de 80 Anos ou mais
8.
Asian J Endosc Surg ; 17(4): e13360, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39019481

RESUMO

INTRODUCTION: Obesity impairs patients' quality of life (QoL). Laparoscopic sleeve gastrectomy (LSG) is a common procedure for patients with severe obesity; however, studies reporting changes in obesity-related QoL are limited. The aim of this study was to assess changes in obesity-related QoL and food tolerance in the early postoperative period. METHODS: We included 20 consecutive patients who underwent LSG between May 2021 and July 2023. We evaluated changes in obesity-related QoL 6 months after surgery using an obesity and weight loss QoL questionnaire (OWLQOL) and a weight related symptom measure (WRSM). Additionally, we assessed eating satisfaction and food tolerance after surgery. RESULTS: The percentages of total weight loss and excess weight loss were 28.5% and 79.1%, respectively. OWLQOL scores and WRSM changed from 36.5 to 73.0 points and from 44.0 to 15.0 points (p = .007, .007), respectively. The food tolerance score decreased from 25 to 21.2 points (p < .001), while eating satisfaction showed no significant change (p = .25). CONCLUSION: Obesity-related QoL is enhanced even in the early postoperative period, without sacrificing eating satisfaction. The findings of this study may provide valuable insights for patients when considering LSG.


Assuntos
Gastrectomia , Laparoscopia , Obesidade Mórbida , Qualidade de Vida , Redução de Peso , Humanos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Obesidade Mórbida/psicologia , Satisfação do Paciente , Período Pós-Operatório , Inquéritos e Questionários , Ingestão de Alimentos/psicologia
9.
Clin Oral Implants Res ; 24 Suppl A100: 134-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22220565

RESUMO

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.


Assuntos
Fosfatos de Cálcio/uso terapêutico , Implantação Dentária Endóssea , Implantes Dentários , Seio Maxilar/cirurgia , Levantamento do Assoalho do Seio Maxilar/métodos , Biópsia , Regeneração Óssea , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , Imuno-Histoquímica , Osteocalcina/metabolismo , Tomografia Computadorizada por Raios X
10.
Surg Case Rep ; 9(1): 139, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37548808

RESUMO

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.

11.
Opt Express ; 20(19): 21739-48, 2012 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-23037293

RESUMO

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.

12.
Sci Rep ; 12(1): 5135, 2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35332191

RESUMO

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].

13.
Artigo em Inglês | MEDLINE | ID: mdl-35353090

RESUMO

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.


Assuntos
Implantes Dentários , Satisfação do Paciente , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Feminino , Seguimentos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
14.
Opt Express ; 19(3): 2448-55, 2011 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-21369064

RESUMO

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.


Assuntos
Amplificadores Eletrônicos , Cerâmica/química , Lasers , Lentes , Temperatura Baixa , Desenho de Equipamento , Análise de Falha de Equipamento
15.
RSC Adv ; 11(34): 20701-20707, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35479358

RESUMO

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.

16.
Water Res ; 177: 115804, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32302807

RESUMO

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.


Assuntos
Argila , Solo , Adsorção , Césio , Radioisótopos de Césio , Descontaminação , Minerais
17.
Anal Sci ; 36(2): 241-245, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31564678

RESUMO

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.

18.
J Hazard Mater ; 387: 121677, 2020 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-31784126

RESUMO

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.

19.
Opt Lett ; 34(21): 3439-41, 2009 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19881620

RESUMO

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.


Assuntos
Cerâmica , Temperatura Baixa , Lasers de Estado Sólido , Itérbio
20.
Dalton Trans ; 47(30): 10063-10070, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-29987285

RESUMO

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.

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