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1.
J Helminthol ; 98: e38, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38721629

RESUMO

The deepest recorded depth for trematodes currently stands at approximately 6200 m. This depth record was achieved solely through sequence datasets of Lepidapedon sp. obtained from a gastropod. Given that trematodes of this genus typically use fish as definitive hosts, the origin of the trematode sequence was thought to be larval stages. However, the specific species remained unclear owing to the absence of reported adult-stage sequences. In the present study, we definitively identified the deepest trematode as Lepidapedon oregonense by comparing 28S ribosomal DNA sequences from adult worms from the macrourid fish Coelorinchus gilberti with data from the gastropod in the previous study.


Assuntos
DNA de Helmintos , DNA Ribossômico , Filogenia , RNA Ribossômico 28S , Trematódeos , Animais , Trematódeos/classificação , Trematódeos/genética , Trematódeos/isolamento & purificação , RNA Ribossômico 28S/genética , DNA de Helmintos/genética , DNA Ribossômico/genética , Gastrópodes/parasitologia , Análise de Sequência de DNA , Peixes/parasitologia , Doenças dos Peixes/parasitologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterinária
2.
ESMO Open ; 7(4): 100527, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35843080

RESUMO

BACKGROUND: Mature progression-free survival (PFS) data from the phase III J-ALEX study showed superiority for alectinib versus crizotinib [hazard ratio (HR) 0.37, 95% confidence interval (CI) 0.26-0.52; median PFS 34.1 versus 10.2 months, respectively] in advanced ALK (anaplastic lymphoma kinase)-positive non-small-cell lung cancer (NSCLC). Overall survival (OS) data were immature (HR 0.80, 99.8799% CI 0.35-1.82) at the time of data cut-off (30 June 2018). We report final OS data after ≥5 years of follow-up. PATIENTS AND METHODS: ALK inhibitor naive Japanese patients who were chemotherapy naive or had received one prior chemotherapy regimen were enrolled. Patients were randomized to receive alectinib 300 mg (n = 103) or crizotinib 250 mg (n = 104) twice daily until progressive disease, unacceptable toxicity, death, or withdrawal. The primary endpoint was independent review facility-assessed PFS, with OS (not fully powered) as a secondary endpoint. RESULTS: Median duration of OS follow-up was 68.6 months with alectinib and 68.0 months with crizotinib. Treatment with alectinib did not prolong OS relative to crizotinib (HR 1.03, 95.0405% CI 0.67-1.58; P = 0.9105). Five-year OS rates were 60.9% (95% CI 51.4-70.3) with alectinib and 64.1% (95% CI 54.9-73.4) with crizotinib. In total, 91.3% (n = 95/104) of crizotinib-treated patients and 46.6% (n = 48/103) of alectinib-treated patients received at least one subsequent anticancer therapy. After study drug discontinuation, 78.8% of patients in the crizotinib arm switched to alectinib, while 10.7% of patients in the alectinib arm switched to crizotinib as a first subsequent anticancer therapy. Patients randomized to crizotinib tended to switch treatment earlier than those randomized to alectinib. CONCLUSION: Final OS analysis from J-ALEX did not show superiority of alectinib to crizotinib; this result was most likely confounded by treatment crossover. Alectinib remains a standard of care for the treatment of patients with advanced ALK-positive NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carbazóis , Crizotinibe , Humanos , Japão , Piperidinas , Inibidores de Proteínas Quinases , Análise de Sobrevida
3.
Orphanet J Rare Dis ; 15(1): 269, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993765

RESUMO

STUDY OBJECTIVES: Niemann-Pick type C (NPC) is an autosomal recessive and congenital neurological disorder characterized by the accumulation of cholesterol and glycosphingolipids. Symptoms include hepatosplenomegaly, vertical supranuclear saccadic palsy, ataxia, dystonia, and dementia. Some cases frequently display narcolepsy-like symptoms, including cataplexy which was reported in 26% of all NPC patients and was more often recorded among late-infantile onset (50%) and juvenile onset (38%) patients. In this current study, we examined CSF orexin levels in the 10 patients of NPC with and without cataplexy, which supports previous findings. METHODS: Ten patients with NPC were included in the study (5 males and 5 females). NPC diagnosis was biochemically confirmed in all 10 patients, from which 8 patients with NPC1 gene were identified. We compared CSF orexin levels among NPC, narcoleptic and idiopathic hypersomnia patients. RESULTS: Six NPC patients with cataplexy had low or intermediate orexin levels. In 4 cases without cataplexy, their orexin levels were normal. In 5 cases with Miglustat treatment, their symptoms stabilized or improved. For cases without Miglustat treatment, their conditions worsened generally. The CSF orexin levels of NPC patients were significantly higher than those of patients with narcolepsy-cataplexy and lower than those of patients with idiopathic hypersomnia, which was considered as the control group with normal CSF orexin levels. DISCUSSION: Our study indicates that orexin level measurements can be an early alert of potential NPC. Low or intermediate orexin levels could further decrease due to reduction in the neuronal function in the orexin system, accelerating the patients' NPC pathophysiology. However with Miglustat treatment, the orexin levels stabilized or improved, along with other general symptoms. Although the circuitry is unclear, this supports that orexin system is indeed involved in narcolepsy-cataplexy in NPC patients. CONCLUSION: The NPC patients with cataplexy had low or intermediate orexin levels. In the cases without cataplexy, their orexin levels were normal. Our study suggests that orexin measurements can serve as an early alert for potential NPC; furthermore, they could be a marker of therapy monitoring during a treatment.


Assuntos
Cataplexia , Doença de Niemann-Pick Tipo C , 1-Desoxinojirimicina/análogos & derivados , 1-Desoxinojirimicina/uso terapêutico , Cataplexia/tratamento farmacológico , Feminino , Humanos , Masculino , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Orexinas
4.
BMJ Open ; 9(5): e025729, 2019 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31061030

RESUMO

OBJECTIVES: An operations leader (OL) takes an important role in occupational health management for radiation decontamination workers in Japan, and candidates for the position must participate in a training session to acquire the necessary knowledge as required by law. However, it has not been clarified whether the candidates for the OL position actually possess accurate knowledge regarding occupational health management for such work after the training session. We, therefore, aimed at examining the current occupational health management knowledge among the candidates and investigating factors related to the knowledge, with hypothesis that possession of accurate knowledge is associated with prior experience of having worked in radiation decontamination. DESIGN: A cross-sectional study. SETTING: The training sessions held by Fukushima Prefecture Labor Standard Associations in Fukushima, Japan, in 2017. PARTICIPANTS: Eighty male candidates participated in the training sessions. OUTCOME: The number/proportion of correct answers to the questions regarding occupational health management, such as those on working environment management, control of operations and health management. RESULTS: The proportion of those who possessed accurate knowledge regarding working environment management, control of operations and health management was 68.8%, 55.0% and 51.2%, respectively. Experience of radiation decontamination work was associated with the possession of inaccurate knowledge regarding working environment management (OR 0.140 (95% CI 0.042 to 0.464)), and the uncertainty of future radiation decontamination work schedules in difficult-to-return zones was associated with the possession of accurate knowledge regarding health management (OR 4.344 (95% CI 1.509 to 12.50)). CONCLUSIONS: Previous experience in radiation decontamination work may hinder the ability to acquire accurate information regarding working environment management among candidates for an OL position. To promote adequate occupational health management for radiation decontamination workers, it is required to establish an effective instructional method for the OL candidate training sessions with consideration of previous relevant experience.


Assuntos
Descontaminação , Gestão do Conhecimento , Liderança , Doenças Profissionais/psicologia , Saúde Ocupacional/educação , Adulto , Ansiedade/psicologia , Estudos Transversais , Acidente Nuclear de Fukushima , Humanos , Japão , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Centrais Nucleares , Exposição Ocupacional , Exposição à Radiação , Inquéritos e Questionários , Local de Trabalho
5.
Dis Esophagus ; 32(3)2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30085020

RESUMO

Neoadjuvant chemotherapy (NAC) is administered to many patients with esophageal squamous cell carcinoma (ESCC) prior to surgery, but it is also true that some of these patients demonstrated no response to the therapy following surgery. In addition, the prognosis of advanced case such as ESCC patients with lymph node metastasis has remained relatively low. Programmed death ligand-1 (PD-L1) in conjunction with tumor-infiltrating lymphocytes (TILs) has been studied as a potential mechanism of "immune escape" in several human malignancies. Therefore, in this study, we studied PD-L1 status in carcinoma cells and forkhead box protein 3 (FOXP3) and CD8 status among TILs in the residual tumors of primary and metastatic sites following NAC. We also studied the association of these factors with the clinicopathological findings in 44 patients with ESCC harboring lymph node metastasis. There was discordance in the pathological response to chemotherapy between the primary tumor and lymph node metastasis, and histologically identified resistance to NAC in lymph node metastases tended to be correlated with an adverse clinical outcome (P = 0.0765) than resistance in the primary tumor. Both univariate and multivariate analyses for disease-specific survival (DSS) revealed that the PD-L1 status of carcinoma cells in metastatic lymph nodes and a higher FOXP3/CD8 ratio in the primary tumor were both significantly correlated with an eventual adverse clinical outcome of the patients (P = 0.0178, P = 0.0463, respectively). These results all indicated that the PD-L1 status of carcinoma cells in metastatic lymph nodes and the FOXP3/CD8 ratio in primary tumors could predict eventual clinical outcomes in ESCC patients with NAC.


Assuntos
Antígeno B7-H1/metabolismo , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Terapia Neoadjuvante/mortalidade , Antígenos CD8/metabolismo , Quimioterapia Adjuvante/mortalidade , Terapia Combinada , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/mortalidade , Carcinoma de Células Escamosas do Esôfago/patologia , Esofagectomia/mortalidade , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Linfonodos/metabolismo , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Resultado do Tratamento
6.
Eur Arch Paediatr Dent ; 20(2): 65-72, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30378001

RESUMO

AIM: To assess the knowledge, attitudes and behaviour of dentists nationwide in Ireland regarding the infant oral health visit, and also to elucidate whether dentists were aware of the recommendation for a first dental visit by age 1 year and of what care should be provided at this visit. METHODS: A validated 10-item questionnaire was distributed to a representative sample of non-paediatric dentists (non-PDs) and paediatric dentists (PDs) practicing in Ireland. The questionnaire focused on respondents' demographics in addition to their knowledge, attitudes and behaviour regarding the infant dental visit. RESULTS: Seventy-three percent of non-PDs reported seeing patients aged 0-36 months. Compared to all PD respondents, 58% of non-PDs believed that the first dental visit should occur by age 1 year. Furthermore, non-PDs provided the same care as PDs at the infant dental visit, with the exception of evaluating for fluoride needs and placing fluoride varnish. The main barrier to early oral healthcare was reported to be parents not requesting dental appointments for their infants. CONCLUSIONS: There remains a need to increase the proportion of non-PDs in Ireland seeing infants by their first birthday. It is recommended that Irish undergraduate and continuing education courses incorporate clinical training regarding the infant oral health visit and emphasise fluoride needs evaluation and fluoride varnish application. Additionally, a nationwide health promotion initiative is indicated to inform parents of the importance of a dental visit by age 1 year.


Assuntos
Assistência Odontológica para Crianças , Saúde Bucal , Atitude , Atitude do Pessoal de Saúde , Criança , Pré-Escolar , Odontólogos , Humanos , Lactente , Recém-Nascido , Irlanda , Padrões de Prática Odontológica
8.
Phys Chem Chem Phys ; 20(17): 12112-12119, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29676424

RESUMO

Anharmonicity plays a crucial role in hydrogen transfer reactions in hydrogen-bonding systems, which leads to a peculiar spectral line shape of the hydrogen stretching mode as well as highly complex intra/intermolecular vibrational energy relaxation. Single-molecule study with a well-defined model is necessary to elucidate a fundamental mechanism. Recent low-temperature scanning tunnelling microscopy (STM) experiments revealed that the cis↔cis tautomerization in a single porphycene molecule on Cu(110) at 5 K can be induced by vibrational excitation via an inelastic electron tunnelling process and the N-H(D) stretching mode couples with the tautomerization coordinate [Kumagai et al. Phys. Rev. Lett. 2013, 111, 246101]. Here we discuss a pronounced anharmonicity of the N-H stretching mode observed in the STM action spectra and the conductance spectra. Density functional theory calculations find a strong intermode coupling of the N-H stretching with an in-plane bending mode within porphycene on Cu(110).

9.
Br Dent J ; 224(1): 2-3, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29326457
10.
Dis Esophagus ; 31(7)2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29346536

RESUMO

In esophageal squamous cell carcinoma (ESCC) patients who are treated with chemoradiotherapy (CRT), identification of the presence or absence of residual or recurrent carcinoma is usually pivotal in their clinical management. In addition, the extent of carcinoma invasion into the esophageal wall could determine the clinical outcome of these patients following CRT. Therefore, in this study, we evaluated the response to CRT both macroscopically and histologically in a consecutive series of 42 ESCC patients receiving neoadjuvant chemoradiotherapy following curative esophageal resection at Tohoku University Hospital between August 2011 and December 2012. The histological grading of tumor regression was as follows: grade 3, markedly effective (no viable residual tumor cells); grade 2, moderately effective (residual tumor cells in less than one-third of the tumor); grade 1, slightly effective (1b, residual tumor cells in one-third to two-thirds of the tumor; 1a, residual tumor cells in more than two-thirds of the tumor); and grade 0, ineffective. In this study, we selected grade 2 and 1b cases because they might show a complete response with definitive CRT. We evaluated the presence of any residual in situ lesions and tumor depth in detail. The grading of tumor regression in primary sites was as follows: grade 3 (7 cases), grade 2 (16 cases), grade 1b (13 cases), and grade 1a (6 cases). The concordance rate between macroscopic and histopathological evaluation on the depth of the tumor was 40% (17/42). Among 29 cases (grade 2 and grade 1b), intraepithelial lesions were not detected in 17 cases, and tumor nests were not detected in the lamina propria mucosae in 9 cases. The results of this study highlight the difficulties of detecting residual carcinoma cells using conventional endoscopic biopsy in patients who have received CRT. Therefore, when residual cancer is clinically suspected in patients who have received CRT, the biopsy specimen should be obtained from the deep layer of the esophagus whenever possible. Additionally, close follow-up is required using positron emission tomography/computed tomography, endoscopy, and other radiological evaluations.


Assuntos
Carcinoma de Células Escamosas/patologia , Quimiorradioterapia Adjuvante/métodos , Neoplasias Esofágicas/patologia , Idoso , Biópsia , Carcinoma de Células Escamosas/terapia , Ressecção Endoscópica de Mucosa , Mucosa Esofágica/patologia , Mucosa Esofágica/cirurgia , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas do Esôfago , Esofagectomia , Esôfago/patologia , Esôfago/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Neoplasia Residual , Período Pós-Operatório , Resultado do Tratamento
12.
Phys Chem Chem Phys ; 19(7): 4921-4937, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28168258

RESUMO

We describe various experimental approaches that have been used to obtain a detailed understanding of double hydrogen transfer in porphycene, a model system for intramolecular hydrogen bonding and tautomerism. The emerging picture is that of a multidimensional tautomerization coordinate, with several vibrational modes acting as reaction-promoters or inhibitors through anharmonic intermode coupling. Tunnelling processes, coherent in the case of isolated molecules and incoherent in condensed phases, are found to play a major role even at elevated temperatures. Single-molecule spectroscopy studies reveal large fluctuations in hydrogen transfer rates observed over time for the same chromophore. Scanning probe microscopy is employed to directly observe the structure and tautomerization dynamics of single molecules adsorbed on metal surfaces and demonstrates how the interactions of the molecules with atoms of the supporting surface affect their static and dynamic properties: different tautomeric forms are stabilized for molecules depending on the surface structure and the reaction mechanism can also change, from a concerted to a stepwise transfer. The scanning probe microscopy studies prove that tautomerization in single molecules can be induced by different stimuli: heat, electron attachment, light, and force exerted by the microscope's tip. Possible applications utilizing tautomerism are discussed in combination with molecular architectures on surfaces, which could pave the way for the development of single-molecule electronics.

13.
Opt Express ; 24(23): 26956-26971, 2016 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-27857423

RESUMO

The use of resonant whispering gallery modes (WGMs) for sensing exhibits various drawbacks and critical points related to the microsphere and tapered optical fiber fabrication tolerance. The uncertainty on the fiber taper and microsphere geometry or the gap between the microsphere and the fiber taper can complicate or limit the actual use of these devices for sensing, requiring peculiar calibration of the WGM based sensing set-up. An alternative double-step approach is proposed in this paper. In particular, the geometrical parameters of the set-up are recovered preliminarily and then the rare earth parameters are recovered via simple transmittance/gain measurements. The method is based on a refined electromagnetic model of the device suitably integrated with a particle swarm optimization (PSO) approach. The percent errors made on the up-conversion coefficients Cup and C3 are extremely low, being 0.75%, 0.05%, respectively. The procedure is very robust. It can be applied more in general, allowing the sensing of other physical parameters via simple transmittance measurements instead of wavelength shift ones, in both microsphere and microbubble based set-up.

14.
J Phys Condens Matter ; 28(49): 494003, 2016 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-27731306

RESUMO

Using combined low-temperature scanning tunneling microscopy and Kelvin probe force microscopy we studied the local electronic structure and work function change of the (0 0 0 1)-oriented epitaxial ZnO layers on a Ag(1 1 1) substrate. Scanning tunneling spectroscopy (STS) revealed that the conduction band minimum monotonically downshifts as the number of the ZnO layers increases up to 4 monolayers (ML). However, it was found by field emission resonance (FER) spectroscopy that the local work function of Ag(1 1 1) slightly decreases for 2 ML thick ZnO but it dramatically changes and drops by about 1.2 eV between 2 and 3 ML, suggesting a structural transformation of the ZnO layer. The spatial variation of the conduction band minimum and the local work function change were visualized at the nanometer scale by mapping the STS and FER intensities. Furthermore, we found that the ZnO layers contained line defects with a few tens of nm long, which can be removed by the injection of a tunneling electron into the conduction band.

15.
J Neurol Sci ; 368: 272-6, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27538648

RESUMO

Febrile infection-related epilepsy syndrome (FIRES), or acute encephalitis with refractory, repetitive partial seizures (AERRPS), is an epileptic encephalopathy beginning with fever-mediated seizures. The etiology remains unclear. To elucidate the genetic background of FIRES/AERRPS (hereafter FIRES), we recruited 19 Japanese patients, genotyped polymorphisms of the IL1B, IL6, IL10, TNFA, IL1RN, SCN1A and SCN2A genes, and compared their frequency between the patients and controls. For IL1RN, the frequency of a variable number of tandem repeat (VNTR) allele, RN2, was significantly higher in the patients than in controls (p=0.0067), and A allele at rs4251981 in 5' upstream of IL1RN with borderline significance (p=0.015). Haplotype containing RN2 was associated with an increased risk of FIRES (OR 3.88, 95%CI 1.40-10.8, p=0.0057). For SCN1A, no polymorphisms showed a significant association, whereas a missense mutation, R1575C, was found in two patients. For SCN2A, the minor allele frequency of G allele at rs1864885 was higher in patients with borderline significance (p=0.011). We demonstrated the association of IL1RN haplotype containing RN2 with FIRES, and showed a possible association of IL1RN rs4251981 G>A and SCN2A rs1864885 A>G, in Japanese patients. These preliminary findings suggest the involvement of multiple genetic factors in FIRES, which needs to be confirmed by future studies in a larger number of FIRES cases.


Assuntos
Encefalopatias/genética , Citocinas/genética , Predisposição Genética para Doença/genética , Polimorfismo Genético/genética , Canais de Sódio/genética , Encefalopatias/complicações , Criança , Pré-Escolar , Epilepsias Parciais/complicações , Feminino , Genótipo , Humanos , Lactente , Japão , Masculino , Estudos Retrospectivos , Convulsões Febris/complicações
16.
Eur J Clin Nutr ; 70(5): 582-7, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26956126

RESUMO

BACKGROUND/OBJECTIVES: The population of the obese is increasing worldwide. Prevention and improvement of obesity are indispensable for decreasing the risk of metabolic disorders. We have recently shown that obesity and fatty liver are reduced by a plant-derived lactic acid bacterium, Pediococcus pentosaceus LP28 (LP28), in high-fat diet-induced obese mice. The aim of the present clinical study is to prove that LP28 is effective for reducing body fat and body weight, as shown in the experiment using mice. SUBJECTS/METHODS: The clinical trial was carried out as a double-blind, randomized, placebo-controlled study comprising 62 subjects (20-70 years of age, BMI 25-30 kg/m(2)). These subjects were randomly assigned to three groups that received living LP28, heat-killed LP28 or a placebo powder, administered orally once a day for 12 weeks. RESULTS: Heat-killed LP28 reduced BMI (0.45 kg/m(2), 95% CI (0.04, 0.86), P=0.035), body fat percentage (1.11%, (0.39, 1.82), P=0.002), body fat mass (1.17 kg (0.43, 1.92), P=0.004) and waist circumference (2.84 cm (0.74, 4.93), P=0.009) when compared with a placebo group. Fasting plasma glucose, HbA1c, fasting insulin, HOMA-IR and serum lipids levels did not change by either living LP28 or heat-killed LP28 intake. CONCLUSIONS: Heat-killed LP28 displays an antiobesity effect that reduces BMI, body fat and waist circumference, suggesting that the plant-derived lactic acid bacterium LP28 would be a promising preventive of metabolic syndrome.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Sobrepeso/terapia , Pediococcus pentosaceus , Probióticos/uso terapêutico , Tecido Adiposo/microbiologia , Adulto , Idoso , Índice de Massa Corporal , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sobrepeso/fisiopatologia , Resultado do Tratamento , Circunferência da Cintura , Adulto Jovem
17.
Nano Lett ; 16(2): 1034-41, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26796945

RESUMO

Molecular switches are of fundamental importance in nature, and light is an important stimulus to selectively drive the switching process. However, the local dynamics of a conformational change in these molecules remain far from being completely understood at the single-molecule level. Here, we report the direct observation of photoinduced tautomerization in single porphycene molecules on a Cu(111) surface by using a combination of low-temperature scanning tunneling microscopy and laser excitation in the near-infrared to ultraviolet regime. It is found that the thermodynamically stable trans configuration of porphycene can be converted to the metastable cis configuration in a unidirectional fashion by photoirradiation. The wavelength dependence of the tautomerization cross section exhibits a steep increase around 2 eV and demonstrates that excitation of the Cu d-band electrons and the resulting hot carriers play a dominant role in the photochemical process. Additionally, a pronounced isotope effect in the cross section (∼100) is observed when the transferred hydrogen atoms are substituted with deuterium, indicating a significant contribution of zero-point energy in the reaction. Combined with the study of inelastic tunneling electron-induced tautomerization with the STM, we propose that tautomerization occurs via excitation of molecular vibrations after photoexcitation. Interestingly, the observed cross section of ∼10(-19) cm(2) in the visible-ultraviolet region is much higher than that of previously studied molecular switches on a metal surface, for example, azobenzene derivatives (10(-23)-10(-22) cm(2)). Furthermore, we examined a local environmental impact on the photoinduced tautomerization by varying molecular density on the surface and find substantial changes in the cross section and quenching of the process due to the intermolecular interaction at high density.

18.
Rev Sci Instrum ; 85(11): 11E114, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25430293

RESUMO

A fast time response, wide dynamic range neutron flux monitor has been developed toward the LHD deuterium operation by using leading-edge signal processing technologies providing maximum counting rate up to ∼5 × 10(9) counts/s. Because a maximum total neutron emission rate over 1 × 10(16) n/s is predicted in neutral beam-heated LHD plasmas, fast response and wide dynamic range capabilities of the system are essential. Preliminary tests have demonstrated successful performance as a wide dynamic range monitor along the design.

19.
Neuroimage ; 94: 250-262, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24657778

RESUMO

Brain function critically relies on the supply with energy substrates (oxygen and glucose) via blood flow. Alterations in energy demand as during neuronal activation induce dynamic changes in substrate fluxes and blood flow. To study the complex system that regulates cerebral metabolism requires the combination of methods for the simultaneous assessment of multiple parameters. We developed a multimodal imaging device to combine positron emission tomography (PET) with laser speckle imaging (LSI) and RGB reflectometry (RGBR). Depending on the radiotracer, PET provides 3-dimensional quantitative information of specific molecular processes, while LSI and RGBR measure cerebral blood flow (CBF) and hemoglobin oxygenation at high temporal and spatial resolution. We first tested the functional capability of each modality within our system and showed that interference between the modalities is negligible. We then cross-calibrated the system by simultaneously measuring absolute CBF using (15)O-H2O PET (CBF(PET)) and the inverse correlation time (ICT), the LSI surrogate for CBF. ICT and CBF(PET) correlated in multiple measurements in individuals as well as across different animals (R(2)=0.87, n=44 measurements) indicating that ICT can be used for absolute quantitative assessment of CBF. To demonstrate the potential of the combined system, we applied it to cortical spreading depression (CSD), a wave of transient cellular depolarization that served here as a model system for neurovascular and neurometabolic coupling. We analyzed time courses of hemoglobin oxygenation and CBF alterations coupled to CSD, and simultaneously measured regional uptake of (18)F-2-fluoro-2-deoxy-D-glucose ((18)F-FDG) used as a radiotracer for regional glucose metabolism, in response to a single CSD and to a cluster of CSD waves. With this unique combination, we characterized the changes in cerebral metabolic rate of oxygen (CMRO2) in real-time and showed a correlation between (18)F-FDG uptake and the number of CSD waves that passed the local tissue. Finally, we examined CSD spontaneously occurring during focal ischemia also referred to as peri-infarct depolarization (PID). In the vicinity of the ischemic territory, we observed PIDs that were characterized by reduced CMRO2 and increased oxygen extraction fraction (OEF), indicating a limitation of oxygen supply. Simultaneously measured PET showed an increased (18)F-FDG uptake in these regions. Our combined system proved to be a novel tool for the simultaneous study of dynamic spatiotemporal alterations of cortical blood flow, oxygen metabolism and glucose consumption under normal and pathologic conditions.


Assuntos
Mapeamento Encefálico/instrumentação , Encéfalo/metabolismo , Glucose/metabolismo , Microscopia Confocal/instrumentação , Oxigênio/metabolismo , Fotometria/instrumentação , Tomografia por Emissão de Pósitrons/instrumentação , Animais , Isquemia Encefálica/metabolismo , Circulação Cerebrovascular , Colorimetria/instrumentação , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Desenho de Equipamento , Análise de Falha de Equipamento , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Distribuição Tecidual , Imagens com Corantes Sensíveis à Voltagem/instrumentação
20.
Rev Sci Instrum ; 85(2): 02B307, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24593584

RESUMO

A helium ion beam is injected into a linear plasma device for the development of an ion beam source simulating high energy particle flux in divertor plasma. Beam current density more than 10 mA/cm(2) is extracted. Measurement of beam currents indicates that the beam is transported along the linear device and reaches to the downstream end plate.

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