Microscopic image restoration based on tensor factorization of rotated patches

In microscopic image processing for analyzing biological objects, structural characters of objects such as symmetry and orientation can be used as a prior knowledge to improve the results. In this study, we incorporated filamentous local structures of neurons into a statistical model of image patches and then devised an image processing method based on tensor factorization with image patch rotation. Tensor factorization enabled us to incorporate correlation structure between neighboring pixels, and patch rotation helped us obtain image bases that well reproduce filamentous structures of neurons. We applied the proposed model to a microscopic image and found significant improvement in image restoration performance over existing methods, even with smaller number of bases.     

Zone-melted unidirectional solidification of particulate dispersed composites

In order to solve the problem of particles settling and agglomeration in front of solidifying interface in unidirectional solidification (UDS) experiments, a zone-melted process has been utilized in this study. The experimental results show that, the melting zone could be kept in 30–40 mm width and the zone melted UDS experiments are realized with Al₂O₃ particle reinforced aluminum-matrix composites. But particle settling still occurs in the liquid, and becomes severe as the particle volume fraction decreases. However, when the volume fraction of the particles is more than 20–22 vol.%, no further settling occurs under a solidification rate of 8–16 mm/h. Investigation on the interaction of particles and solid/liquid interface reveals that the Al₂O₃ particles are rejected into liquid and pushed by the growing solid phase in Al₂O_3(P)/Al and Al₂O_3(P)/Al-0.23wt.%Ce composites. Some particles are mechanically entrapped between cells, and distributed along the crystal grain boundaries.     

Prevention by inhibitors of arachidonic acid cascade of liver carcinogenesis, cirrhosis and oxidative DNA damage caused by a choline-deficient, L-amino acid-defined diet in rats

Effects of inhibitors of arachidonic acid (AA) cascade on the development of fatty liver, cirrhosis, glutathione S-transferase placental form (GST-P)-positive preneoplastic nodules, neoplastic nodules and generation of 8-hydroxydeoxyguanosine (8-OHdG), caused by a choline-deficient, L-amino acid-defined (CDAA) diet, were examined in Fischer 344 male rats by feeding CDAA diet supplemented with the inhibitors for 12 and 30 weeks. None of the inhibitors affected fatty liver. Among cyclooxygenase (COX) inhibitors, an irreversibly acting acetylsalicylic acid and a long-acting piroxicam, and to a much lesser extent the short-acting ibuprofen but not indomethacin, inhibited the development of cirrhosis, GST-P-positive and neoplastic nodules and generation of 8-OHdG. A phospholipase A2 inhibitor p-bromophenacylbromide (BPB) also exerted similar but lesser extent of inhibitory effects. Lipoxygenase inhibitors quercetin and nordihydroguiaretic acid inhibited GST-P-positive nodules but not cirrhosis or 8-OHdG. Present results suggest that perturbed AA cascade, particularly augmented COX pathway, might play key roles in the causation of liver lesions in the CDAA diet model.     

Plasma endotoxin and cytokine concentrations in patients with hemorrhagic shock

OBJECTIVES: The roles of cytokines and endotoxin in hemorrhagic shock, particularly the translocation of endotoxin and bacteria during hemorrhagic shock, were investigated. DESIGN: Prospective study. SETTING: Critical care and emergency center of a university hospital. PATIENTS: Twenty-nine patients with hemorrhagic shock and 20 healthy controls. INTERVENTIONS: Serial blood samples were collected from both study and control patients. Standard resuscitation techniques were used. MEASUREMENTS AND MAIN RESULTS: Plasma levels of endotoxin and various cytokines were determined repeatedly during hemorrhagic shock. Endotoxin was measured using an endotoxin-specific assay in addition to a new perchloric acid method for pretreatment of plasma. Cytokines were measured by commercial enzyme-linked immunosorbent assays. Plasma endotoxin concentrations remained within the normal range for 7 days after admission. Although levels of tumor necrosis factor-alpha and several interleukins increased slightly in some patients, these cytokines did not reach the levels seen in septic shock. CONCLUSIONS: Translocation of bacteria or endotoxin from the gastrointestinal tract into the bloodstream has been noted in animal experiments; however, translocation was not detected in our patients with hemorrhagic shock.     

Improvement of exercise capacity by sarpogrelate as a result of augmented collateral circulation in patients with effort angina

OBJECTIVES: The purpose of this study was to evaluate whether a serotonin blocker, sarpogrelate, improves exercise capacity as a result of vasodilation of coronary collateral channels in patients with effort angina. BACKGROUND: Serotonin has been reported to decrease coronary collateral blood flow by collateral vasoconstriction in a canine model, suggesting that platelet activation in feeding coronary arteries of the collateral network has the potential to cause collateral vasoconstriction. METHODS: The subjects consisted of 22 patients with effort angina and reproducible ischemic threshold (group A, 11 patients with thrombolysis in myocardial infarction (TIMI) grade 2 or 3 flow of the ischemia-related coronary artery and Rentrop's collateral index 0 or 1; group B, 11 patients with TIMI grade 0 or 1 flow and Rentrop's collateral index 2 or 3). We repeated the symptom-limited treadmill exercise test using the Balke-Ware protocol and exercise tetrofosmin myocardial perfusion scintigraphy with and without pretreatment with 200 mg orally administered sarpogrelate. Each exercise test was performed at 9:00 a.m. on different days. The order of tests with and without sarpogrelate was randomized. RESULTS: In group A, sarpogrelate increased neither exercise time at 0.1 mV ST depression nor double product at 0.1 mV ST depression. In contrast, in group B sarpogrelate increased the exercise duration at 0.1 mV ST depression from 181+/-112 (SD) to 248+/-131 s (p < 0.05) and also increased the double product at 0.1 mV ST depression by 21% (p < 0.01). The severity score using myocardial perfusion scintigraphy at the same workload was significantly (p < 0.01) decreased by 37% in group B, but not in group A (11%), due to the sarpogrelate treatment. CONCLUSIONS: Sarpogrelate augments flow reserve of the collateral circulation and improves exercise capacity in anginal patients with well-developed collaterals. These findings indicate that a serotonin blocker, sarpogrelate, is useful not only as an antiplatelet drugs, but as an antianginal drug.     

Electrical conductivity and thermoelectric power in irradiated UO2 + x

Two kinds of UO_{2 + x}, the O/U ratios of which were 2.002 and 2.004, respectively, were irradiated to a dose range between 1.14 × 10¹⁴ and 1.90 × 10¹⁸ fissions/cm³, and electrical conductivity changes were measured. A steep decrease in conductivity was observed with increasing dose up to 1 × 10¹⁵ fissions/cm³, a gradual increase followed between 1 × 10¹⁵ and 1 × 10¹⁸ fissions/cm³ and above this dose the conductivity abruptly increased. Thermoelectric power measurements were also carried out for the specimens irradiated in the dose range up to 1.90 × 10¹⁸ fissions/cm³. It might be suggested that p-type conduction contributes to the electrical conductivity in irradiated specimens up to 1.90 × 10¹⁸ fissions/cm³.     

Transient induced creep for irradiated fuels

Creep of nuclear fuels under irradiation has generally been considered as an athermal process. A transient state of irradiation induced creep, however, was treated with kinetic equations based on thermodynamics. For this purpose, the kinetic equations for enhanced diffusion, annihilation of excess vacancies and migration probability under irradiation were derived. Effective works were introduced to the above processes as a result of the fission damage, and reduced activation energies for each process were defined. Based on the knowledge obtained in the transient state, the effective activation energies in the steady state were discussed. The above concepts were examined using the experiments of Clough.     

A method of single-phase PWM for an independent power supply in photovoltaic power generation systems

We propose a method of single-phase PWM for an independent power supply in photovoltaic power generation systems. This new PWM is derived by comparing levels of signal waves with one of carrier waves which have bipolar swing different from unipolar swing in the conventional PWM. In this PWM, we can use a battery with lower voltage in combination with the photovoltaic power generation; fundamental level of output voltage is raised by about 11%, though poor in quality of waveforms. © 1998 Scripta Technica. Electr Eng Jpn, 122(4): 55–62, 1998     

Plasma alpha 2-macroglobulin-trypsin complexlike substance (MTLS) in pancreatic disease

alpha 2-macroglobulin-trypsin complexlike substance (MTLS) was determined in plasma of pancreatic and nonpancreatic diseases using a two-step enzyme immunoassay to study the diagnostic and pathophysiological significance of MTLS. Plasma levels of MTLS in acute pancreatitis (mean +/- SD = 265.6 +/- 346.2 ng/ ml, n = 9), calcified chronic pancreatitis (128.6 +/- 257.4, n = 13), and noncalcified chronic pancreatitis (13.5 +/- 12.5, n = 10) were significantly higher than that in controls (3.6 +/- 1.8, n = 81). In other diseases such as gastric cancer, hepatoma, diabetes mellitus, and gallstones, MTLS values were not different from those of control. Plasma MTLS values showed low correlation with serum trypsin, elastase 1, pancreatic amylase, lipase, and pancreatic secretory trypsin inhibitor (PSTI). The elevation of plasma MTLS values in acute pancreatitis suggests that plasma MTLS levels reflect that protease is inappropriately activated in pancreatic acinar cell and released into the circulation and that the determination of MTLS can be useful for diagnosis and pathophysiology of acute pancreatitis and chronic pancreatitis.     

Continuous thoracic epidural blockade in combination with general anesthesia with nitrous oxide, oxygen, and sevoflurane in two patients with myasthenia gravis

Continuous thoracic epidural anesthesia (T4/5) using 4-5 ml.h-1 of 1.5% lidocaine with 1:200,000 epinephrine and inhaled anesthesia using nitrous oxide, oxygen and sevoflurane were performed in two patients, (40 and 22 yr-old females) with myasthenia gravis. This combined anesthetic technique provided muscle relaxation for endotracheal intubation and optimal operating conditions, including muscle relaxation and stability of hemodynamics during transsternal thymectomy. Further, continuous epidural anesthesia using 4 ml.h-1 of 0.25% bupivacaine provided postoperative pain relief without other analgesics and stable postoperative respiratory conditions. In conclusion, we confirm the benefits of this technique which provides not only safe and stable conditions during the surgery, but also an improved comfort for patients in the postoperative period following transsternal thymectomy for myasthenia gravis.