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Tohru Araki

Publications and source records attributed to Tohru Araki.

12 recordsLinked to original sources
PubMed2006

Comet 81P/Wild 2 under a microscope.

The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.

Journal Article↗
PubMed2006

Organics captured from comet 81P/Wild 2 by the Stardust spacecraft.

Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples.

Carbon↗
PubMed2006

Speciation and quantitative mapping of metal species in microbial biofilms using scanning transmission X-ray microscopy.

A scanning transmission X-ray microscope illuminated with synchrotron light was used to investigate the speciation and spatial distributions of metals in a microbial biofilm cultivated from river water. Metal 2p absorption edge signals were used to provide metal speciation (through shapes of the absorption spectra) and quantitative spatial distributions of the metal species. This paper presents sample data and describes methods for extracting quantitative maps of metal species from image sequences recorded in the region of the metal 2p edges. Comparisons were made with biochemical characterization of the same region using images recorded at the C 1s and O 1s edges. The method is applied to detailed quantitative analysis of ferrous and ferric iron in a river biofilm, in concert with mapping Ni(II) and Mn(II) species in the same region. The distributions of the metal species are discussed in the context of the biofilm structure. These results demonstrate that soft X-ray STXM measurements at the metal 2p absorption edges can be used to speciate metals and to provide quantitative spatial distribution maps for metal species in environmental samples with 50 nm spatial resolution.

Biofilms↗
PubMed2006

[A study of 4,031 patients of transurethral resection of the prostate performed by one surgeon: learning curve, surgical results and postoperative complications].

A total of 4,031 patients who underwent transurethral resection of the prostate (TURP) performed by one surgeon between May 1979 and December 2003 were retrospectively examined to determine the improvement of the surgeon's skill in performing TURP assessed by using a learning curve, surgical results and postoperative complications. Analysis using the learning curve, which displayed the relationship between the number of TURP procedures and the speed of resection (i.e., the weight of tissue resected divided by the operation time), revealed that 81 operations were needed before the surgeon's skill reached a plateau in performing TURP. The means +/- standard deviations of the weight of tissue resected, operation time and speed of resection were 17.0 +/- 14.6 g, 21.0 +/- 13.5 minutes, 0.80 +/- 0.32 g/minutes, respectively. As the number of TURP procedures increased and the level of skill improved, the operation time was significantly reduced and the speed of resection was significantly increased. The incidences of postoperative complications were 2.4% for blood transfusion, 0.3% for the TURP syndrome, 1.5% for hemostatic procedures, 2.8% for bladder neck contracture, and 1.0% for urethral stricture. The incidences of transfusion and the TURP syndrome decreased as the surgeon's skill improved. The mortality rate was 0.1%.

Aged↗
PubMed2005

Quantitative chemical mapping of sodium acrylate- and N-vinylpyrrolidone-enhanced alginate microcapsules.

Alginate microcapsules enclosing recombinant cells secreting therapeutic products have been used successfully to treat several murine models of human diseases. The mechanical and chemical properties of these alginate capsules can be improved by the addition and in situ photo-polymerization of sodium acrylate and N-vinylpyrrolidone in the alginate capsule. The purpose of this modification was to form additional covalent cross-links. In this work we have used scanning transmission X-ray microscopy (STXM) to probe the nature and location of the chemical modifications in the modified capsules by comparison with unmodified capsules. Analysis of X-ray image sequences and selected area spectra has been used to map the calcium gradient in capsules, to identify the presence of polyacrylate throughout the capsules and the localization of poly-N-vinylpyrrolidone in the outer regions of the alginate capsules. The differences in the spatial distributions of these species have led to better understanding of the chemical modifications that provide a mechanically more stable capsule structure.

Acrylates↗
PubMed2005

[Transurethral resection for prostatic adenoma larger than 100 ml--preoperative treatment with interstitial laser coagulation of the prostate plus chlormadinone acetate as a treatment maneuver for safer operations].

Between August 1985 and March 2004, we performed transurethral resection of the prostate (TURP) in 18 patients with benign prostatic hyperplasia (BPH) whose prostatic volume was larger than 100 ml. We divided the patients into two groups. Group A consisted of a total of 14 cases: 10 cases whose mean prostate volume was 114 ml (100 to 137 ml) and 4 cases whose prostate volume was not measured before TURP but whose mean resected prostatic tissue weight was 113 g (105 to 118 g). Group B consisted of 4 cases whose mean prostate volume was 110 ml (101 to 133 ml). Patients in group B underwent interstitial laser coagulation of the prostate (ILCP) followed by oral chlormadinone acetate (CMA) therapy (50 mg/day); TURP was performed 6 months later, once the prostate volume had shrunk to an average of 76 ml (66 to 91 ml). Mean resected weights and operation times were: group A, 93.1 g, 66.3 min; group B, 60.5 g, 55.7 min. There were 12 blood transfusion cases (85.7%; intraoperative) in group A, and 1 (25.0%; POD 1) in group B. Accordingly, this preoperative treatment was considered a safer method of TURP for BPH 100 ml or more. There were no cases of TURP syndrome or death in either group.

Aged↗
PubMed2004

Effectiveness of a nonsteroidal anti-inflammatory drug for nocturia on patients with benign prostatic hyperplasia: a prospective non-randomized study of loxoprofen sodium 60 mg once daily before sleeping.

We explored the effectiveness of loxoprofen sodium (loxoprofen), which is the most common non-steroidal anti-inflammatory drug (NSAID) in Japan, for patients with benign prostatic hyperplasia (BPH) complaining of nocturia. A total of 93 BPH patients aged 49-84 years were enrolled in the study. These patients had received standard drug therapy with alpha1-blocker for BPH, followed by anticholinergic drugs, hypnotics, tricyclic antidepressants, and/or antiduretic hormone, but they still complained about 2 or more episodes of nocturia. They each took a single 60-mg tablet of loxoprofen prior to sleeping at night for 14 days in addition to their BPH treatments. The effects were assessed by questionnaire before and after treatment as excellent (nocturia disappeared or decreased by 2 or more voids/night), improved (nocturia decreased by 1 void/night), unchanged, or worsened (nocturia increased). Nocturia improved or disappeared in 74.2% of patients: excellent, improved, unchanged, and worsened results were obtained in 37.6%, 36.6%, 21.5%, and 4.3% of patients, respectively. The effects were better in patients whose baseline nocturia was > 2 times than in those with a lesser frequency at enrollment (P = 0.04). Loxoprofen can be an effective and useful treatment option for patients with BPH complaining of refractory nocturia.

Aged↗
PubMed2003

Plasma brain natriuretic peptide and the evaluation of volume overload in infants and children with congenital heart disease.

This study was designed to explore whether it was possible to evaluate the severity of VSD, PDA, and ASD by measuring brain natriuretic peptide (BNP) levels. We also investigated normal BNP levels in children to provide a baseline for our study. We measured BNP levels in 253 normal children, including 11 normal neonates, and in 91 VSD patients, 29 PDA patients, and 34 ASD patients. BNP levels showed no age-related differences in normal children (the mean value: 5.3 +/- 3.8 pg/ml). In the healthy neonates, BNP levels rose from 10.4 +/- 11.9 pg/ml in cord blood to 118.8 +/- 83.2 pg/ml on day 0, then fell to 15.3 +/- 7.8 pg/ml by day 7. In VSD and PDA patients, BNP levels correlated significantly with Qp/Qs, LVEDV, and peak RVP/LVP. In ASD patients, BNP levels correlated with Qp/Qs and RVEDV. Especially, in VSD patients, as an index corresponding to 1.5-2.0 of the Qp/Qs ratio, BNP levels of 20-35 pg/ml were found to be best with regard to both sensitivity and specificity. In the healthy neonates, BNP levels changed rapidly after birth. In VSD, PDA, and ASD patients, BNP levels were well-correlated with the severity of the disease. Especially, in VSD patients, it that appears BNP levels may be useful in evaluating surgical indications, with 20-35 pg/ml levels being the appropriate cut-off value.

Adolescent↗
PubMed2002

Langmuir monolayers and the transferred films of fluorinated amphiphiles containing vinyl groups.

The monolayer behavior of long-chain esters of acrylic and methacrylic acids containing perfluoro or partially fluorinated carbon chains at the air/water interface was studied by surface pressure-area isotherm measurements and Brewster angle microscopy. It has been found that a minor change in the chemical structures of these fluorinated amphiphiles, such as a hydrogen substituted at the omega-position of the hydrophobic fluorocarbon tails instead of a fluorine as well as hydrophilic vinyl ester groups inserted between acrylates and methacrylates, induces a drastic change in the isotherms for the monolayers, suggesting different molecular orientation and packing in the films. The monolayers were transferred by horizontal lifting, Langmuir-Blodgett, and surface-lowering methods to give the X-, Y-, and Z-type films, respectively. These films were characterized by scanning probe microscopy, to clarify the mesoscopic surface structures of the molecular films exposed with the hydrophilic or hydrophobic moieties in air, depending upon the dipping methods. The Z-type films with the outermost surface of the fluorinated substituents were examined in relation to the frictional properties that strongly depend upon the fluorine and the hydrogen atoms at the end of the hydrophobic fluorocarbon chains, which is controllable at the atomic level.

Journal Article↗
PubMed2002

[Clinical study of influential factors on renal scarring after ESWL monotherapy for renal stone disease].

OBJECTIVE: ESWL is now widely used for the treatment of renal stone disease. Although ESWL has many advantages for patients' quality of life, few reports have demonstrated the long-term outcomes of the alterations of renal morphology after ESWL. We reported renal scarring after ESWL monotherapy in patients with renal calyceal stones. In this study, we evaluated a large series of patients' cohort treated at our institution, and assessed the causal effect of ESWL on the late occurrence of renal scar formation. PATIENTS AND METHODS: ESWL was performed with EDAP (LT-01,02) that generates shock wave energy by piezoelectric discharge. We analyzed the records of 285 kidneys treated between Dec. 1986 and Nov. 1998. Renal scarring was noted in 44 kidneys and not in 241 kidneys with periodical ultrasonography. We compared the backgrounds of the two groups using chi-square or non-parametric analysis. The Kaplan-Meier method and Cox regression model determined the analysis of renal scar formation. RESULTS: Univariate and multiple regression analysis revealed that the total amount of ESWL emission and hyperuricemia independently affected the probability of renal scar formation. CONCLUSIONS: Over-emission of ESWL (over 10,000 shots) must be care for the prevention of renal scarring in patients with renal calyceal calculi, especially when associated with hyperuricemia. After ESWL, periodical checkups with ultrasonography will provide useful information for the clinical diagnosis of renal scarring.

Adult↗
PubMed2002

[A clinical study on renal pelvic and ureteral cancer].

We investigated the clinicopathological features of 62 patients with transitional cell carcinoma of the renal pelvis and/or ureter who underwent total nephroureterectomy at our department from April, 1987 to October, 2000. The patients consisted of 48 males and 14 females, with a mean age of 67 years, ranging from 46 to 86 years. The mean follow-up period was 40 months. The 1-, 3- and 5-year cause-specific survival rates (Kaplan-Meier's method) for all of the patients were 90.8, 82.9%, and 68.6%, respectively. The prognostic significance of the 5 pathological factors (grade, pT, pV, pL and pN) were evaluated. All these factors affected the survival rates significantly in univariate analysis using the generalized Wilcoxon test. According to multivariate analysis by the Cox proportional hazard model, the most influential prognostic factor was grade.

Aged↗