166 research outputs found
A Z-scheme type photoelectrochemical cell consisting of porphyrin-containing polymer and dye-sensitized TiO2 electrodes
In photosynthesis, two photosystems are exquisitely located for uphill electron transport with redox species to bridge these photosystems and this is called Z-scheme type structure. This smart photoenergy conversion system must be modeled in highlyefficient artificial photoenergy conversion. Our strategy here is to cooperate a couple of photoactive electrodes for mimicking a Z-scheme type structure using two different photoelectrodes and bridging redox couple. An early study implied the possibility of a tandem-type photoelectric conversion system, though the cell performance had been considerably low. 1 Later, Bach's group also proposed a similar structure consisting of nand p-type dye-sensitized solar cell (DSC) electrodes and achieved high conversion efficiency. Recently, we reported a simple fabrication method of photoactive polymer electrode consisting of 5,10,15,20-tetra(3-thienyl)-21H,23H-porphyrin (TThP) and 2,2¢-bithiophene (BiTh) by electropolymerization (Scheme 1a). 6-9 As the photoactive electrode for a solar cell, it could generate 32% of photon-to-electron conversion efficiency under the monochromatic light. Since this polymer electrode functions as a photocathode and has a good affinity with the I -/I 3 -redox couple, it is very fascinating to use in a Z-scheme type photoelectrochemical cell with a smart choice of a good compatible photoanode. In this paper, we found that the combination of the above-described polymer electrode and the electrode for DSC successfully acted as a Z-scheme type photoelectrochemical cell with higher photovoltage TThP was synthesized by condensation of pyrrole (Aldrich) and 3-thiophenecarboxyaldehyde (Aldrich) according to the previous procedures. 6 TThP was identified by 1 H-NMR, absorption spectroscopy, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) and elemental analysis; impurities in the TThP were found to be negligible. (TThP+polythiophene (pTh)) thin films were fabricated on the surface of an indium-tin-oxide (ITO) glass by electrochemical polymerization of TThP and BiTh (Wako pure chemicals) in a similar manner as before. 6 The ITO glass (Sanyo Vacuum Industries, 2 ¥ 2 ¥ 0.3 cm), cleaned ultrasonically in 2-propanol and then dichloromethane, was used as a working electrode. A platinum wire and a silver wire were used as the counter and reference electrodes, respectively. A dichloromethane solution This journal i
Association of coronary revascularisation after physician-referred non-invasive diagnostic imaging tests with outcomes in patients with suspected coronary artery disease: a post hoc subgroup analysis
Objective: We aimed to evaluate the association of the prognostic impact of coronary revascularisation with physician-referred non-invasive diagnostic imaging tests (single photon emission CT (SPECT) vs coronary CT angiography) for coronary artery disease. Design: A post hoc analysis of a subgroup from the patient cohort recruited for the Japanese Coronary-Angiography or Myocardial Imaging for Angina Pectoris Study. Setting: Multiple centres in Japan. Participants: From the data of 2780 patients with stable angina, enrolled prospectively between January 2006 and March 2008 in Japan, who had undergone physician-referred non-invasive imaging tests, 1205 patients with SPECT as an initial strategy and 625 with CT as an initial strategy were analysed. We assessed the effect of revascularisation (within 90 days) in each diagnostic imaging stratum and the interaction between the two strata. Primary and secondary outcome measures: Major adverse cardiac events (MACEs), including death, myocardial infarction, hospitalisation for heart failure and late revascularisation, were followed up for 1 year. The χ2 test, Student’s t-test, Kaplan-Meier analysis, log-rank test and multivariable Cox proportional hazard model were used in data analysis. Results: A total of 210 (17.4%) patients in the SPECT stratum and 149 (23.8%) in the CT stratum underwent revascularisation. Although in each stratum, the cumulative 1 year incidence of MACEs was significantly higher in patients who underwent revascularisation than in those who did not (SPECT stratum: 9.1 vs 1.2%, log-rank p<0.0001; CT stratum: 6.1 vs 0.8%, log-rank p=0.0001), there was no interaction between the risk of revascularisation and the imaging strata (SPECT stratum: adjusted HR (95% CI), 4.25 (1.86–9.72); CT stratum: 4.13 (1.16–14.73); interaction: p=0.97). Conclusion: The association of revascularisation with the outcomes of patients with suspected coronary artery disease was not different between SPECT-first and CT-first strategies in a physician-referred fashion
Local relapse of nasopharyngeal cancer and Voxel-based analysis of FMISO uptake using PET with semiconductor detectors
Background: Hypoxic cancer cells are thought to be radioresistant and could impact local recurrence after radiotherapy (RT). One of the major hypoxic imaging modalities is [18F]fluoromisonidazole positron emission tomography (FMISO-PET). High FMISO uptake before RT could indicate radioresistant sites and might be associated with future local recurrence. The predictive value of FMISO-PET for intra-tumoral recurrence regions was evaluated using high-resolution semiconductor detectors in patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy (IMRT). Methods: Nine patients with local recurrence and 12 patients without local recurrence for more than 3 years were included in this study. These patients received homogeneous and standard doses of radiation to the primary tumor irrespective of FMISO uptake. The FMISO-PET image before RT was examined via a voxel-based analysis, which focused on the relationship between the degree of FMISO uptake and recurrence region. Results: In the pretreatment FMISO-PET images, the tumor-to-muscle ratio (TMR) of FMISO in the voxels of the tumor recurrence region was significantly higher than that of the non-recurrence region (p < 0.0001). In the recurrent patient group, a TMR value of 1.37 (95% CI: 1.36-1.39) corresponded to a recurrence rate of 30%, the odds ratio was 5.18 (4.87-5.51), and the area under the curve (AUC) of the receiver operating characteristic curve was 0.613. In all 21 patients, a TMR value of 2.42 (2.36-2.49) corresponded to an estimated recurrence rate of 30%, and the AUC was only 0.591. Conclusions: The uptake of FMISO in the recurrent region was significantly higher than that in the non-recurrent region. However, the predictive value of FMISO-PET before IMRT is not sufficient for up-front dose escalation for the intra-tumoral high-uptake region of FMISO. Because of the higher mean TMR of the recurrence region, a new hypoxic imaging method is needed to improve the sensitivity and specificity for hypoxia
A phase I clinical trial for [131I]meta-iodobenzylguanidine therapy in patients with refractory pheochromocytoma and paraganglioma : a study protocol
Objective Pheochromocytoma and paraganglioma (PPGLs) are rare neuroendocrine tumors derived from the adrenal medulla or extra-adrenal paraganglioma from extra-adrenal chromaffin tissue. Although malignant PPGLs has miserable prognosis, the treatment strategy remains to be established. An internal radiation therapy using [131I]meta-iodobenzylguanidine (131I-mIBG) called MIBG therapy has been attempted as one of the systemic treatment of malignant PPGLs. The aim of this study is therefore to evaluate the safety and the efficacy of MIBG therapy for refractory PPGLs. Methods Patients with refractory PPGLs will be enrolled in this study. The total number of patients for registration is 20. The patients receive a fixed dose of 7,400 MBq of 131I-mIBG. Adverse events are surveyed during 20 weeks after 131I-mIBG injection and all severe adverse events will be documented and reported in detail in accordance with the Common Terminology Criteria for Adverse Events (CTCAE). Examination and imaging diagnosis are performed in 12 weeks after 131I-mIBG injection for the evaluation of therapeutic effect in accordance with the Response Evaluation in Solid Tumours (RECIST). Conclusion The current study is the first multi-institutional prospective study of MIBG therapy and thereby will play a significant role in improving the patients’ prognosis of refractory PPGLs
Enhanced diagnostic accuracy for quantitative bone scan using an artificial neural network system: A Japanese multi-center database project
Background Artificial neural network (ANN)-based bone scan index (BSI), a marker of the amount of bone metastasis, has been shown to enhance diagnostic accuracy and reproducibility but is potentially affected by training databases. The aims of this study were to revise the software using a large number of Japanese databases and to validate its diagnostic accuracy compared with the original Swedish training database. Methods The BSI was calculated with EXINIbone (EB; EXINI Diagnostics) using the Swedish training database (n = 789). The software using Japanese training databases from a single institution (BONENAVI version 1, BN1, n = 904) and the revised version from nine institutions (version 2, BN2, n = 1,532) were compared. The diagnostic accuracy was validated with another 503 multi-center bone scans including patients with prostate (n = 207), breast (n = 166), and other cancer types. The ANN value (probability of abnormality) and BSI were calculated. Receiver operating characteristic (ROC) and net reclassification improvement (NRI) analyses were performed. Results The ROC analysis based on the ANN value showed significant improvement from EB to BN1 and BN2. In men (n = 296), the area under the curve (AUC) was 0.877 for EB, 0.912 for BN1 (p = not significant (ns) vs. EB) and 0.934 for BN2 (p = 0.007 vs. EB). In women (n = 207), the AUC was 0.831 for EB, 0.910 for BN1 (p = 0.016 vs. EB), and 0.932 for BN2 (p < 0.0001 vs. EB). The optimum sensitivity and specificity based on BN2 was 90% and 84% for men and 93% and 85% for women. In patients with prostate cancer, the AUC was equally high with EB, BN1, and BN2 (0.939, 0.949, and 0.957, p = ns). In patients with breast cancer, the AUC was improved from EB (0.847) to BN1 (0.910, p = ns) and BN2 (0.924, p = 0.039). The NRI using ANN between EB and BN1 was 17.7% (p = 0.0042), and that between EB and BN2 was 29.6% (p < 0.0001). With respect to BSI, the NRI analysis showed downward reclassification with total NRI of 31.9% (p < 0.0001). Conclusion In the software for calculating BSI, the multi-institutional database significantly improved identification of bone metastasis compared with the original database, indicating the importance of a sufficient number of training databases including various types of cancers. © 2013 Nakajima et al
Lung uptake on I-131 therapy and short-term outcome in patients with lung metastasis from differentiated thyroid cancer
Investigating nuclear shell structure in the vicinity of 78Ni: Low-lying excited states in the neutron-rich isotopes 80,82Zn
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Supramolecular structures formed by the self assembly of ionic fullerenes in binary liquid mixtures
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