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1.
Materials (Basel) ; 14(8)2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33917087

RESUMO

Orthodontic miniscrews have gained popularity; however, they have some drawbacks, including screw loosening that results from bone resorption caused by excess microdamage created during screw insertion. Pilot hole preparation through the cortical bone is considered beneficial to avoid such microdamage, while an overly large pilot hole impairs primary stability. Hence, we used a human bone analogue to evaluate the microdamage and primary stability to estimate the optimal pilot hole size that would minimize the screw loosening risk. Ti6Al4V orthodontic miniscrews and 1.0-mm-thick synthetic cortical bone pieces were prepared. Various compressive loads were applied in indentation tests to test pieces' surfaces, and the microdamaged areas were confirmed as stress-whitening zones. Screw insertion tests were performed in which a miniscrew was inserted into the test pieces' pilot hole with a diameter of 0.7-1.2 mm in 0.1-mm intervals, and the stress-whitening area was measured. The insertion and removal torque were also measured to evaluate primary stability. The stress-whitening areas of the 1.0-1.2 mm pilot hole diameter groups were significantly smaller than those of the other groups (p < 0.05), whereas the 0.9 and 1.0 mm pilot hole diameter groups showed higher primary stability than other groups. In conclusion, the bone analogue could be utilized to evaluate microdamage in cortical bones and the primary stability of miniscrews.

2.
J Oral Rehabil ; 47(12): 1489-1495, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32813891

RESUMO

BACKGROUND: Dysphagia is a growing health problem in aging societies. An observational cohort study targeting community-dwelling populations revealed that 16% of elderly subjects present with dysphagia. There is a need in elderly communities for systematic dysphagia assessment. OBJECTIVE: This study aimed to verify whether laryngeal elevation in the pharyngeal phase could be measured from the body surface using thin and flexible stretch sensors. METHODS: Thirty-two elderly subjects (17 males, 15 females; mean age ± SD: 89.2 ± 6.2 years) with suspected dysphagia underwent a swallowing contrast examination in which seven stretch sensors were attached to the front of the neck. The elongation of the sensors was measured and compared to the laryngeal elevation time values obtained using videofluorography. The sensor signal detected the laryngeal elevation start time, conclusion of the descent of the larynx, and the laryngeal elevation time. The respective laryngeal elevation times obtained using videofluorography and using the sensor were compared using the Bland-Altman method. RESULTS: The laryngeal elevation time was 1.34 ± 0.46 s with the stretch sensor and 1.49 ± 0.56 s with videofluorography. There was a significant positive correlation between the duration obtained by both methods (r = .69, P < .0001). A negative additional significant bias of -0.15 s (95% confidence interval -0.30 to -0.03, P = .046) was noted in the laryngeal elevation time from the videofluorography measurement. CONCLUSION: Laryngeal elevation time can be measured non-invasively from the neck surface using stretch sensors.


Assuntos
Transtornos de Deglutição , Laringe , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Deglutição , Transtornos de Deglutição/diagnóstico por imagem , Feminino , Humanos , Laringe/diagnóstico por imagem , Masculino , Faringe/diagnóstico por imagem
3.
Gan To Kagaku Ryoho ; 46(13): 2521-2523, 2019 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-32156985

RESUMO

Intraductal papillary mucinous neoplasm(IPMN)of the pancreas often presents with multifocal lesions. Complete resection without residual skip lesions is essential for complete eradication of the disease. We experienced a case of IPMC in which intraoperative pancreatoscopy was used to determine the surgical margin. Intraoperative pancreatoscopy is a useful and easy method to evaluate the remnant duct and exclude residual tumor. A cystic lesion was incidentally detected in the pancreatic head of a 78-year-old man. Ultrasonography, abdominal computed tomography, magnetic resonance imaging, and endoscopic ultrasound revealed enhancing mural nodules in the pancreatic head and dilation of the entire main pancreatic duct. We performed pancreaticoduodenectomy for mixed IPMN. Intraoperative pancreatoscopy, which was performed to rule out skip lesions, showed no mucosal abnormalities in the remnant duct. The pathological diagnosis was non-invasive intraductal papillary-mucinous carcinoma(IPMC). No signs of recurrence were seen for 6 postoperative months.


Assuntos
Carcinoma Papilar , Neoplasias Pancreáticas , Idoso , Carcinoma Papilar/cirurgia , Humanos , Masculino , Margens de Excisão , Recidiva Local de Neoplasia , Pancreatectomia , Neoplasias Pancreáticas/cirurgia
4.
Gan To Kagaku Ryoho ; 46(13): 1943-1944, 2019 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-32157020

RESUMO

The patient was a 75-year-old man who was diagnosed as having jejunal gastrointestinal stromal tumor(GIST)and underwent partial resection of the small intestine including the tumor 12 years ago. Two years after the first resection, recurrence was detected, and a second resection was performed. Ten years after the second resection following recurrence, he took imatinib, and computed tomography(CT)revealed abdominal and liver tumors. We was diagnosed as having GIST recurrence, and a third resection, which included an abdominal tumor resection and partial hepatectomy, was performed. The pathological findings were metastatic abdominal GIST and angiomyolipoma of the liver. The Japanese Clinical Practice Guidelines for GIST suggest a surgical indication only for local recurrence of GIST and resectable liver metastases. Recurrent GIST cannot be completely cured with antineoplastic drugs alone. Multidisciplinary treatment is necessary for long-term survival of patients with recurrent GIST.


Assuntos
Angiomiolipoma , Neoplasias Gastrointestinais , Tumores do Estroma Gastrointestinal , Neoplasias Hepáticas , Idoso , Antineoplásicos/uso terapêutico , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/cirurgia , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Mesilato de Imatinib/uso terapêutico , Masculino , Recidiva Local de Neoplasia
6.
Biomed Res Int ; 2017: 3609062, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29392133

RESUMO

Subperiosteal bone-bonding devices have been proposed for less invasive treatments in orthodontics. The device is osseointegrated onto a bone surface without fixation screws and is expected to rapidly attain a bone-bonding strength that successfully meets clinical performance. Hence, the device's optimum shape for rapid and strong bone bonding was examined in this study by finite element analyses. First, a stress analysis was performed for a circular rod device with an orthodontic force parallel to the bone surface, and the estimate of the bone-bonding strength based on the bone fracture criterion was verified with the results of an animal experiment. In total, four cross-sectional rod geometries were investigated: circular (Cr), elliptical (El), semicircular (Sc), and rectangular (Rc). By changing the height of the newly formed bone to mimic the progression of new bone formation, the estimation of the bone-bonding strength was repeated for each geometry. The rod with the Rc cross section exhibited the best performance, followed by those with the Sc, El, and Cr cross sections, from the aspects of the rapid acquisition of strength and the strength itself. Thus, the rectangular cross section is the best for rod-like subperiosteal devices for rapid bone bonding.


Assuntos
Implantes Dentários , Teste de Materiais , Osseointegração , Parafusos Ósseos , Análise do Estresse Dentário , Análise de Elementos Finitos , Humanos , Titânio/química , Titânio/uso terapêutico
7.
PLoS One ; 11(11): e0167100, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27861637

RESUMO

This paper introduces a high-throughput software tool framework called sam2bam that enables users to significantly speed up pre-processing for next-generation sequencing data. The sam2bam is especially efficient on single-node multi-core large-memory systems. It can reduce the runtime of data pre-processing in marking duplicate reads on a single node system by 156-186x compared with de facto standard tools. The sam2bam consists of parallel software components that can fully utilize multiple processors, available memory, high-bandwidth storage, and hardware compression accelerators, if available. The sam2bam provides file format conversion between well-known genome file formats, from SAM to BAM, as a basic feature. Additional features such as analyzing, filtering, and converting input data are provided by using plug-in tools, e.g., duplicate marking, which can be attached to sam2bam at runtime. We demonstrated that sam2bam could significantly reduce the runtime of next generation sequencing (NGS) data pre-processing from about two hours to about one minute for a whole-exome data set on a 16-core single-node system using up to 130 GB of memory. The sam2bam could reduce the runtime of NGS data pre-processing from about 20 hours to about nine minutes for a whole-genome sequencing data set on the same system using up to 711 GB of memory.


Assuntos
Biologia Computacional , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA/métodos , Software , Biologia Computacional/métodos , Exoma , Genoma , Genômica/métodos , Reprodutibilidade dos Testes
8.
Gan To Kagaku Ryoho ; 43(12): 2160-2162, 2016 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-28133255

RESUMO

A 76-year-old male patient was diagnosed with progressive descending colon cancer. Since the patient had severe respiratoryfunction impairment after right pneumonectomy, the anesthesiologydepartment of our hospital determined that general anesthesia induction was too difficult. He was thus started on capecitabine plus oxaliplatin(XELOX)therapy. Three months after starting this treatment, colonoscopyshowed that the site had become scarred, and tissue examination revealed no indication of malignancy. Accordingly, the patient achieved clinical complete response. The patient had no findings of recurrence 1 year and 11 months after the start of chemotherapy. Chemotherapy for unresectable progressive recurrent colorectal cancer is based on the 5-FU anticancer agent, which exerts its antitumor effect byinhibiting DNA synthesis. The antitumor effect is reportedly high when the expression of thymidylate synthase(TS), a target agent, is low. In this patient, TS expression was low based on tissue examination. TS expression maybe an effective useful predictive factor for the efficacyof chemotherapyadministered to patients with unresectable progressive recurrent colorectal cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Colo Descendente/patologia , Neoplasias do Colo/tratamento farmacológico , Desoxicitidina/análogos & derivados , Fluoruracila/análogos & derivados , Pneumopatias/fisiopatologia , Idoso , Capecitabina , Neoplasias do Colo/patologia , Desoxicitidina/uso terapêutico , Fluoruracila/uso terapêutico , Humanos , Pneumopatias/etiologia , Masculino , Oxaloacetatos , Pneumonectomia/efeitos adversos , Resultado do Tratamento
9.
Gan To Kagaku Ryoho ; 42(12): 1959-61, 2015 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-26805230

RESUMO

A 71-year-old man was diagnosed with a gastric tumor approximately 50mm in diameter on computed tomography (CT). In January 2000, he underwent a proximal gastrectomy. Pathological examination showed 5 mitoses per 50 high-power fields, while immunohistochemical analysis showed positive staining for KIT. Accordingly, the tumor was diagnosed as an intermediate- risk malignant gastrointestinal stromal tumor (GIST) for which the patient was followed. In January 2002, an abdominal CT scan revealed multiple hepatic tumors and a lower abdominal tumor, and the patient was diagnosed with liver metastases and peritoneal disseminations from GIST. After informed consent was provided, chemotherapy with 400 mg/day imatinib was initiated. The patient demonstrated a partial response 2 months after treatment. At 12 years 8 months after the diagnosis of liver metastasis and peritoneal disseminations, the patient shows no sign of recurrence.


Assuntos
Antineoplásicos/uso terapêutico , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Mesilato de Imatinib/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Gástricas/patologia , Idoso , Gastrectomia , Tumores do Estroma Gastrointestinal/secundário , Tumores do Estroma Gastrointestinal/cirurgia , Humanos , Neoplasias Hepáticas/secundário , Masculino , Neoplasias Peritoneais/secundário , Prognóstico , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia
10.
Gan To Kagaku Ryoho ; 42(12): 2145-7, 2015 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-26805292

RESUMO

A 76-year-old man underwent surgery for sigmoid colon cancer. The pathological finding was stage Ⅱ with a high-risk of recurrence (SI [bladder], l y0, v2, pN0, H0, P0, M0). He was treated with TS-1 as adjuvant chemotherapy. After the 1 course of chemotherapy, his platelet count was 4,000/mL. The high index of platelet associated IgG (PA-IgG) and bone marrow examination suggested that thrombocytopenia was caused by idiopathic thrombocytopenic purpura. The platelet count improved by prednisolone administration and Helicobacter pylori eradication treatment. After 6 months with no administration of adjuvant chemotherapy, the colon cancer recurred locally, and we performed a Hartmann's operation.


Assuntos
Púrpura Trombocitopênica Idiopática/induzido quimicamente , Neoplasias do Colo Sigmoide/tratamento farmacológico , Silicatos/efeitos adversos , Titânio/efeitos adversos , Idoso , Quimioterapia Adjuvante , Infecções por Helicobacter/terapia , Helicobacter pylori , Humanos , Masculino , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Neoplasias do Colo Sigmoide/cirurgia , Silicatos/uso terapêutico , Titânio/uso terapêutico
11.
Gan To Kagaku Ryoho ; 41(12): 2428-9, 2014 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-25731546

RESUMO

A 74-year-old woman underwent distal gastrectomy and D1+ α dissection for the treatment of gastric cancer (pT2a, pN2, H0, P0, M0, Stage IIIA) in February 2008. She was treated with adjuvant postoperative chemotherapy consisting of TS-1. However, 32 months after the operation, paraaortic lymph node recurrence was confirmed by computed tomography (CT). She was treated with combined TS-1 and cisplatin chemotherapy. After 14 courses, CT revealed that the paraaortic lymph node metastasis had disappeared, and a complete response was attained. The patient is currently disease-free, 6 years after the operation.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Idoso , Combinação de Medicamentos , Feminino , Gastrectomia , Humanos , Metástase Linfática , Ácido Oxônico/administração & dosagem , Recidiva , Indução de Remissão , Silicatos/administração & dosagem , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Tegafur/administração & dosagem , Titânio/administração & dosagem
12.
Gan To Kagaku Ryoho ; 41(12): 1533-5, 2014 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-25731243

RESUMO

A 64-year-old woman underwent cholecystectomy for treatment of cholecystolithiasis in January 2005. Pathological examination rendered a diagnosis of gallbladder carcinoma. Wedge resection of the liver and dissection of the lymph nodes was performed. No tumor cells in either the liver nodule or lymph nodes were found during pathological examination. At 4 years after surgery, paraaortic lymph node recurrence was confirmed by computed tomography (CT). Gemcitabine was administered once weekly for the first 3 weeks in a monthly cycle, but the tumor continued to increase in size. Gemcitabine was then switched to TS-1, after which it was changed to cisplatin because of continued tumor growth. After 35 courses of chemotherapy, CT showed the disappearance of the paraaortic lymph node, and the patient achieved a complete response. She is currently free of disease at 9 years after surgery.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Vesícula Biliar/tratamento farmacológico , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Cisplatino/administração & dosagem , Feminino , Neoplasias da Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/cirurgia , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Recidiva , Silicatos/administração & dosagem , Titânio/administração & dosagem
13.
J Nat Med ; 67(2): 276-80, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22730002

RESUMO

Natural medicinal exudates such as gum arabic are high-molecular-weight natural polysaccharides and are highly soluble in water. The dissolved solutions of these exudates show viscous behavior and exhibit favorable emulsion stability. These exudates have been widely used not only as a medicinal additive, such as a coating agent for tablets and as an emulsifier and stabilizer in beverage and food products, but also for other industrial applications, such as paints and ink. Gum ghatti was originally used as an alternative to gum arabic due to its similar properties to those found in gum arabic. Gum ghatti has been used as a food additive due to its excellent emulsification properties. In this study, we obtained gum ghatti nodules and branches as botanical specimens, which were collected from the same harvesting area. Refined gum ghatti processed from the collected gum ghatti nodules was found to comply with the specifications set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and also to be identical to commercially available gum ghatti products as a food additive. Component analysis of the refined gum ghatti samples revealed that they contain arabinose (34.0-38.0 %), galactose (21.0-24.6 %), mannose (5.3-7.9 %), xylose (0.8-1.2 %), rhamnose (0.8-1.2 %), and glucuronic acid (15.4-18.6 %) as constituent sugars, protein (2.7-3.6 %), moisture (4.9-8.3 %), and tannin (0.041-0.092 %). As a result of the investigation of collected branches as botanical specimens, they were identified as Anogeissus latifolia Wallich. Detailed observation of their morphological characteristics revealed that many crystal cells were aligned in the lengthwise section of branch specimens.


Assuntos
Combretaceae/química , Gomas Vegetais/química , Emulsificantes/química , Aditivos Alimentares/química
14.
Opt Lett ; 37(8): 1382-4, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22513693

RESUMO

Ultra-fast carrier decay, recently discovered in a hydrogenated amorphous silicon waveguide, can be exploited for pattern-effect-free all-optical signal processing based on optical Kerr nonlinearity. In this study, we utilized a 10 Gbit/s RZ-OOK data stream as a pump for degenerate four-wave mixing in a low-loss hydrogenated amorphous silicon waveguide. The propagation loss of the waveguide used was 1.0±0.2 dB/cm at 1550 nm. Unlike crystalline silicon waveguides, no noticeable difference was observed in the BER characteristics between the cases of PRBS 2(7)-1 and 2(31)-1.

15.
Nihon Geka Gakkai Zasshi ; 113(1): 58-61, 2012 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-22413560

RESUMO

A 78-year-old woman was admitted to our hospital because of abdominal pain. She was diagnosed with complex (type IV) paraesophageal hiatal hernia, for which an operation was performed. At laparotomy, a 50 cm long ileum was found to have herniated into the thoracic cavity through the esophageal hiatus along with the sliding hiatal hernia of the stomach. Both the organs were reduced to the abdominal cavity. The hiatal hernia defect (diameter, 7cm) was repaired with a direct suture, and the gastric fundus was sutured to the diaphragm. Presently, 6 years have passed since the operation, there is no sign of recurrence.


Assuntos
Hérnia Hiatal/patologia , Íleo/patologia , Idoso , Feminino , Fundo Gástrico/cirurgia , Hérnia Hiatal/cirurgia , Humanos , Resultado do Tratamento
16.
Gan To Kagaku Ryoho ; 39(2): 285-7, 2012 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-22333645

RESUMO

The patient was a 76-year-old man with no chief complaint. He presented to an internist of our hospital for an evaluation of anemia. An upper gastrointestinal endoscopy revealed a type 2 tumor at the lesser curvature of the gastric body. Although the blood analysis showed a high amount of AFP(2, 328 ng/mL), there was no abnormality found in the liver with a CT scan. The tumor was presumed to be an AFP-producing gastric cancer on the basis of the tumor biopsy. We performed total gastrectomy, splenectomy and cholecystectomy. The tumor cells were positive for AFP by immunohistochemistry. The final diagnosis was hepatoid adenocarcinoma, pT3(SS), INF b, ly1, v2, pN1(3/42), pStage II B. Tumor cells were negative for antihepatocyte antibody and anti-HER2 antibody. The amount of AFP normalized postoperatively. After discharge, he was treated with S-1(80mg/day)orally. He is relapse-free now, 14 months after the operation. Hepatoid adenocarcinoma is an extremely aggressive tumor with a poor prognosis, and effective chemotherapy has still not been established. A larger number of analyses, along with a molecular biological approach, is sure to be helpful for the establishment of an effective treatment for hepatoid adenocarcinoma.


Assuntos
Adenocarcinoma/patologia , Neoplasias Gástricas/patologia , Adenocarcinoma/sangue , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/cirurgia , Idoso , Antimetabólitos Antineoplásicos/uso terapêutico , Terapia Combinada , Combinação de Medicamentos , Humanos , Masculino , Estadiamento de Neoplasias , Ácido Oxônico/uso terapêutico , Neoplasias Gástricas/sangue , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia , Tegafur/uso terapêutico , Tomografia Computadorizada por Raios X , Resultado do Tratamento , alfa-Fetoproteínas/biossíntese
17.
Gan To Kagaku Ryoho ; 38(6): 1039-41, 2011 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-21677504

RESUMO

The patient was a 50-year-old man who underwent total gastrectomy twelve years ago. Ahigh level of ALP was found in the patient in April 2008. Based on various examinations, the diagnosis of multiple bone metastasis of gastric carcinoma accompanying disseminated intravascular coagulation(DIC)was made. The patient was treated with S-1/CDDP. S-1(80mg/ m / / 2day)was administered for 14 days followed by a 7-day rest period, and a CDDP(20mg/m2)infusion was administered on days 1 and 8. After one course of treatment, the DIC was controlled, and the patient was given a one-year prognosis. The combination of S-1 and low-dose CDDP may be considered effective even for multiple bone metastases of gastric carcinoma with DIC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Cisplatino/uso terapêutico , Coagulação Intravascular Disseminada/tratamento farmacológico , Ácido Oxônico/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Tegafur/uso terapêutico , Neoplasias Ósseas/secundário , Cisplatino/administração & dosagem , Coagulação Intravascular Disseminada/etiologia , Combinação de Medicamentos , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Oxônico/administração & dosagem , Prognóstico , Neoplasias Gástricas/complicações , Neoplasias Gástricas/patologia , Tegafur/administração & dosagem
18.
Clin J Gastroenterol ; 4(6): 407-11, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26189745

RESUMO

A 72-year-old man with a history of distal gastrectomy was diagnosed with esophageal cancer (EC). A subtotal esophagectomy and the residual total gastrectomy were performed via a right-sided thoracotomy and laparotomy with D2 lymph node dissection followed by reconstruction with a retrosternal right colonic interposition. The pathological diagnosis was Mt, 65 mm, moderately differentiated squamous cell carcinoma, pT2, ly0, v2, pN0, sM0, pStage II. The patient suddenly developed neurological symptoms 10 days after the operation, and brain magnetic resonance imaging detected a single solid left cerebellar tumor. This tumor was completely excised, and pathological diagnosis confirmed the tumor as an EC metastasis. He received adjuvant chemotherapy with cisplatin + 5-fluorouracil. Seven months later, he developed multiple brain metastases; however, no evidence of local recurrence or other metastatic sites was found. He died 8 months after the surgery. Solitary cerebellar metastasis from EC in which the primary tumor is T2N0 is rare, and the mechanism of this metastatic pattern is of particular interest. Our case study suggests that even if the primary tumor is in the limited stage and other metastatic sites are not identified at presentation, it seems reasonable to perform preoperative imaging of the brain for all patients with EC.

19.
Opt Express ; 18(6): 5668-73, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20389582

RESUMO

We, for the first time, present the ultrafast optical nonlinear response of a hydrogenated amorphous silicon (a-Si:H) wire waveguide using femtosecond pulses. We show cross-phase and cross-absorption modulations measured using the heterodyne pump-probe method and estimate the optical Kerr coefficient and two-photon absorption coefficient for the amorphous silicon waveguide. The pumping energy of 0.8 eV is slightly lower than that required to achieve two-photon excitation at the band gap of a-Si:H (approximately 1.7 eV). An ultrafast response of less than 100 fs is observed, which indicates that the free-carrier effect is suppressed by the localized states in the band gap.


Assuntos
Hidrogênio/química , Refratometria/instrumentação , Silício/química , Desenho de Equipamento , Análise de Falha de Equipamento , Dinâmica não Linear
20.
J Am Chem Soc ; 128(4): 1390-3, 2006 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-16433559

RESUMO

Rechargeable lithium batteries represent one of the most important developments in energy storage for 100 years, with the potential to address the key problem of global warming. However, their ability to store energy is limited by the quantity of lithium that may be removed from and reinserted into the positive intercalation electrode, Li(x)CoO(2), 0.5 < x < 1 (corresponding to 140 mA.h g(-1) of charge storage). Abandoning the intercalation electrode and allowing Li to react directly with O(2) from the air at a porous electrode increases the theoretical charge storage by a remarkable 5-10 times! Here we demonstrate two essential prerequisites for the successful operation of a rechargeable Li/O(2) battery; that the Li(2)O(2) formed on discharging such an O(2) electrode is decomposed to Li and O(2) on charging (shown here by in situ mass spectrometry), with or without a catalyst, and that charge/discharge cycling is sustainable for many cycles.

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