Fabrication of the Large-Area Integrated a-Si Solar Cells

PIN-structure small-area solar cells using a-Si have been frequently reported on, but only a few reports are available on the study of solar cells using a large-area (10-cm square) substrate, all with a resultant conversion efficiency of above 9.0 %[1,2]. Our study has been concentrated on solar cells using a batch of ten 10-cm square substrates with an average conversion efficiency of 9.5 % or more.

As a result, without an anti-reflection coating on the surface of the glass substrate, the following values have been obtained: average conversion efficiency (EFF)=9.63 % (standard deviation of 0.195 %) -Open-circuit voltage (Voc)=12.668 V (standard deviation of 0.215 V) -Short-circuit current (Isc)=78.467 mA (standard deviation of 1.619 mA) -Fill factor (FF)=0.6672 (standard deviation of 0.009)

The process, equipment and methods for measurements through which these results were obtained are described below.

Prospective replacement of magnifying endoscopy by a newly developed endocytoscope, the 'GIF-Y0002'

Endocytoscopy has the potential to reduce the need for histologic examination of biopsy specimens in cases of esophageal squamous cell carcinoma. Up to now, two types of endocytoscope have been used: the probe type and the integrated type. In this study we examined the utility of a newly developed endocytoscope, the 'GIF-Y0002,' which has a single lens allowing consecutive magnification from the conventional endoscopy level up to ×380. Using the GIF-Y0002, we examined 24 examples of normal esophageal mucosa to clarify the appearance of the microvasculature of the normal squamous epithelium in vivo. We also examined 11 cases of esophageal cancer in the same way, employing methylene blue as a vital dye to stain the surface cells. In normal squamous epithelium, we clarified the relationship between the subepithelial capillary network, IPCLs and subepithelial venules. With methylene blue staining, we observed typical squamous cells (low nuclear density and low N/C ratio without nuclear abnormality). When cancerous lesions were observed using lower-power magnification, we were able to visualize their microvascular architecture to the same extent as when conventional magnifying endoscopy was used. Furthermore, at higher magnification, we were able to visualize the features of blood flow in both superficial and advanced cancer. Methylene blue staining revealed an increase of nuclear density in all cases of cancer. The pathologist agreed to omit biopsy histology in 81.8% (9/11) of cancer cases considering the nuclear density and nuclear abnormality. The GIF-Y0002 provides information on cell abnormality in addition to the features revealed by currently available magnifying endoscopy.

[Three cases of spontaneous mediastinal emphysema]

We report 3 cases of spontaneous mediastinal emphysema. All patients were young males, and had predisposing episodes for development of spontaneous mediastinal emphysema; sports in 2, loud voice in 1. The each chief complaint was dyspnea, throat pain, and epigastric pain. Two patients were admitted, but 1 rejected admission despite sufficient informed consent. All patients became asymptomatic with mediastinal air reabsorption within a week. We should recognize spontaneous mediastinal emphysema as one cause of chest, back, neck and epigastric pain.

Endocytoscopic observation for esophageal squamous cell carcinoma: can biopsy histology be omitted?

We examined whether endocytoscopic observation of esophageal squamous cell carcinoma can replace the histologic examination of biopsy specimens. In a basic investigation, we examined 57 iodine-unstained areas in the resected specimens of the esophagus from 28 individuals. The endocytoscopic findings were graded from 0 to 3 in tandem with observations of the iodine staining. For endocytoscopic observation, we sprayed 1% methylene blue or toluidine blue as a vital dye on the surface of the esophageal mucosa, allowing 15-20 s for sufficient staining. One endoscopist observed the target lesions and decided their endocytoscopic type classification. Histological diagnoses were made by two pathologists who were unaware of the endoscopic findings. We then compared the endocytoscopic diagnosis and conventional histological diagnosis. In an in vivo investigation, we examined 71 lesions of esophageal squamous cell carcinoma. Two endoscopists diagnosed the type classification in consultation with a pathologist with regard to 'nuclear density,''nuclear abnormality,' and 'whether biopsy histology could have been omitted on the basis of endocytoscopic findings.' For the in vivo observation, we utilized XEC120U (higher magnification type [x1100]), XEC300F (lower magnification type [x450]), and XGIF-Q260EC1 (lower magnification type [x450]) instruments. In the basic investigation, among the 11 areas classified as Type 1, 10 (91%) were category 1 by the Vienna classification. Among the 39 lesions classified as Type 3, 36 (92%) were category 4 or 5. The sensitivity of endocytoscopy for malignant lesions (Vienna classification categories 4 and 5) was 94.7%, if Type 3 was considered malignant. The specificity was 84.2% according to the same criteria. In the in vivo observation, two endoscopists diagnosed more than 90% of esophageal squamous cell carcinomas as neoplasms using each type of endocytoscope. With regard to nuclear density, the pathologist considered it to be increased in 98% of cases with the XEC120U, in 94% with the XEC300F, and in 93% with the XGIF-Q260EC1. With regard to nuclear abnormality, the positivity rate was 90% with the XEC120U, 78% with the XEC300F, and 80% with the XGIF-Q260EC1. As to whether or not biopsy histology examination was considered necessary, the pathologist made a 'Yes' judgment for 84% of cases observed with the XEC120U, 66% with the XEC300F, and 67% with the XGIF-Q260EC1. Cancerous lesions diagnosed as Type 3 by both endoscopists using the XEC120U accounted for 46 (90.2%) of the 51 cases. Among these 46 cases, biopsy histology was considered unnecessary by the pathologist in 43 (93.5%). We believe that endocytoscopic observation has the potential to reduce the extent of histologic examination of biopsy specimens in cases corresponding to Types 1 and 3 of our classification.

Distribution of nuclear bomb Pu in Nishiyama area, Nagasaki, estimated by accurate and precise determination of 240Pu/239Pu ratio in soils

Plutonium isotopes in forest soils collected in Nishiyama area, Nagasaki, were successfully determined by high resolution inductively coupled plasma mass spectrometry after the treatment with a microwave decomposition system. The (240)Pu/(239)Pu atom ratios observed in the samples in the Nishiyama area were obviously lower than the range of the global fallout. The low ratios (minimum 0.032) observed in Nishiyama area indicated the influence of detonation of the Pu nuclear weapon in 1945. Since the area is contaminated also by global fallout, the (240)Pu/(239)Pu atom ratio can be more sensitive indicator of bomb-derived Pu than Pu activity concentration.

Symptoms of depression, prescription of benzodiazepines, and the risk of death in hemodialysis patients in Japan

Many hemodialysis patients in Japan have symptoms of depression, but whether those patients are treated appropriately is unknown. As part of the Dialysis Outcomes and Practice Patterns Study, data on symptoms of depression, physician-diagnosed depression, prescribed medications, and death were collected prospectively in cohorts in Japan (n=1603) and 11 other countries (n=5872). Symptoms of depression were as prevalent in Japan as elsewhere, but in Japan a much smaller percentage of patients had physician-diagnosed depression: only 2% in Japan vs 17% elsewhere. Antidepressants were much less commonly prescribed in Japan: only 1% in Japan vs 17% elsewhere for patients with many and frequent symptoms of depression, and 16% in Japan vs 34% elsewhere for patients with physician-diagnosed depression. In Japan, symptoms of depression were associated with prescription of benzodiazepines (without antidepressants), and patients with physician-diagnosed depression were twice as likely to be given benzodiazepines: 32% in Japan vs 16% elsewhere. Benzodiazepine monotherapy was associated with death (relative risk 1.56, 95% confidence interval (CI), 1.25-1.94), even after adjustments for 13 likely confounders (relative risk 1.27, 95% CI, 1.01-1.59). Hemodialysis patients in Japan with symptoms of depression are given not antidepressants but benzodiazepines, a practice associated with higher mortality.

Insulin resistance and impaired myocardial fatty acid metabolism in dialysis patients with normal coronary arteries

We investigated whether insulin resistance is associated with impaired cardiac fatty acid metabolism in maintenance hemodialysis patients without coronary artery disease. We studied 55 nondiabetic (63+/-11 years old) and 51 diabetic (61+/-10 years old) hemodialysis patients with normal coronary arteries, using single-photon emission computed tomography (SPECT) with an iodinated fatty acid analogue, iodine-123-beta-methyl iodophenyl-pentadecanoic acid ((123)I-BMIPP), to evaluate cardiac fatty acid metabolism. SPECT imaging was graded regionally from 0 (normal) to 4 (absence of tracer) to calculate a summed score for 17 left ventricular segments. Insulin resistance was determined using the homeostasis model assessment index of insulin resistance (HOMA-IR). HOMA-IR correlated with summed BMIPP score in nondiabetic and diabetic patients. Stepwise multiple regression analysis showed that HOMA-IR was independently associated with BMIPP summed score in nondiabetic (beta=0.774, t=9.218, P=0.0001) and diabetic patients (beta=0.792, t=9.079, P=0.0001). Left ventricular ejection fraction was lower in nondiabetic subjects with BMIPP summed score of at least 6 plus HOMA-IR of at least 4 than in others with lower values for both assessments (53.1+/-13.8%, n=20 vs 67.7+/-9.1%, n=23, P=0.0002); this was also true in diabetic subjects (50.9+/-15.2%, n=24 vs 71.0+/-13.6%, n=11, P=0.0007). Association between insulin resistance and impaired cardiac fatty acid metabolism may contribute to left ventricular dysfunction in patients with maintenance hemodialysis without coronary diseases.

Intracerebral haemorrhage associated with hourly concentration of ambient particulate matter: case-crossover analysis

AIMS

To examine the association of hourly time lagged concentration of ambient particulate matter and death due to stroke.

METHODS

Mortality data for five years (January 1990 to December 1994) were obtained from the Ministry of Health, Labour, and Welfare of Japan. Data were used only if the deceased was 65 years old or older at the time of death, if death was attributed to intracerebral haemorrhage or ischaemic stroke, and if the deceased lived in one of 13 major urban areas. Hourly mean concentrations of PM7, NO2, and photochemical oxidants were measured at monitoring stations in the 13 areas. Time stratified case-crossover analysis was used to examine the data for evidence of triggering stroke mortality.

RESULTS

The 1-hour mean concentration of PM7 measured about 2 hours before death was associated with the risk of death due to intracerebral haemorrhage from April to September (odds ratio = 2.40, 95% CI 1.48 to 3.89, for exposure to PM7 of more than 200 microg/m3 (threshold)). The higher risk was independent of the 24-hour mean concentration of PM7. PM7 was not associated with death due to ischaemic stroke.

CONCLUSIONS

Transiently high concentrations of PM7 are associated with death due to intracerebral haemorrhage. Air quality standards or guidelines for particulate matter should be based not only on 24-hour mean concentrations, but also on hourly data.