243 research outputs found
Hydrogen Production from Methane in Atmospheric Non-Equilibrium Plasma
The instability of supplied power is a serious problem for chemical plants in developing countries. An easy start-up/shut-down system is important in this situation. The present report describes a hydrocarbon decomposition system using nonequilibrium plasma for hydrogen production. A microwave oven was used as a preliminary microwave reactor, which contained a quartz glass tube that passed through the top panel to the bottom panel of the microwave oven. Argon and methane flow were directed into the reactor, where the argon gas became plasma in the tube. A carbon stick was set in the tube as the excitation material of argon to plasma. Initially, the reaction was conducted under a methane partial pressure of 200 hPa. The main products were hydrogen and acetylene, with a small amount of ethylene also produced. Conversion and yields decreased with increasing methane partial pressure. Hydrogen production rate initially increased with methane partial pressure, but then decreased. The optimum methane partial pressure was determined. Gas flow rate had no effect on conversion or yield. The reactant and products reached an equilibrium state as soon as the reactant was introduced to the plasma. Pure hydrogen, 95%, was obtained by adjusting the experimental conditions
Stroke Status Evoked Adhesion Molecule Genetic Alterations in Astrocytes Isolated from Stroke-Prone Spontaneously Hypertensive Rats and the Apigenin Inhibition of Their Expression
We examined the possibility that the expression of adhesion molecules is regulated differently in cultured astrocytes from stroke-prone spontaneously hypertensive rats (SHRSP/IZM) rats than in those from Wistar Kyoto rats (WKY/IZM) by tumor necrosis factor-alpha (TNF-α) or hypoxia and reoxygenation (H/R) and the inhibitory effects of apigenin. It was found that the expression of vascular cell adhesion molecule-1 (VCAM-1) by TNF-α in astrocytes isolated from SHRSP/IZM was increased compared with that in WKY/IZM. The expression of monocyte chemotactic protein-1 (MCP-1) mRNA induced by H/R in SHRSP/IZM astrocytes was increased compared with that in normal oxygen concentrations. Apigenin strongly attenuated TNF-α-induced VCAM-1 mRNA and protein expression and suppressed the adhesion of U937 cells and SHRSP/IZM astrocytes. These results suggest that the expression levels of adhesion molecules during H/R affect disease outcome and can drive SHRSP/IZM to stroke. It is suggested that apigenin regulates adhesion molecule expression in reactive astrocytes during ischemia
Evaluation of intramuscular lateral distribution profile of topically administered acetaminophen in rats
To clarify to what extent topically administered drug molecules horizontally permeate into tissues surrounding the administration site, the intramuscular lateral concentration profile of acetaminophen was investigated in vivo using the microdialysis method in rats. When acetaminophen was intramuscularly administered for 6 hr in a pinpoint manner at a constant rate of 3 μg/min, it was clearly detected in the muscle surrounding the administration site, being 17.5 μg/ml when measured at a 2 mm distance from the administration site. The concentration in the muscle was decreased as the distance increased, and those measured at 5 mm and 40 mm were 0.35 μg/ml and 0.09 μg/ml, respectively. In addition, it was shown that the concentration in the muscle at 40 mm reflected the compound’s concentration in plasma, but not the compound’s horizontal
permeation from the administration site. With these observations, the intramuscular distribution profile of acetaminophen was numerically characterized according to Fick’s law. As a result, it was revealed that horizontal permeation is the primary process accountable for the increased intramuscular concentration only in the area adjacent to the administration
site, and the radius of the adjacent area was calculated to be 5.80 mm for acetaminophen. </p
Bolted connections for non-intersecting H-section beam and column in steel moment frames
This research proposes connection configurations of two types for non-intersecting H-section steel beam and column. To elucidate the mechanical behavior of the proposed connections, full-scale moment connection tests and finite element analyses were conducted using T-shaped partial frame models. Comparisons between the proposed connections and regular intersecting connections demonstrate that the proposed connection is able to provide sufficient stiffness and energy-dissipation capacity if the beam and column flanges are designed to provide sufficient shear resistance. Then to understand the global behavior of frames using the proposed connections, pushover analyses of a two-story two-span frame were conducted. Because the bending moment of the beam acts on the column by a torque through the proposed connections, torsion spring models were incorporated for representing the proposed connections in 3D frame analysis. Analysis results showed that the girders and columns exhibited lower stiffness and strength than those of frames with intersecting connections because of torsion. To overcome this issue, torsion restraint by secondary beams with different configurations was discussed and optimal configuration was suggested. By utilizing the optimal configuration, torsion of girders and columns can be efficiently reduced into a similar level as that of regular intersecting connections
Effect of Intravenous Immunostimulant (OK-432)
To clarify the effectiveness of OK-432, immunopotentiator was intravenously used. The tumor-bearing host was apparently stimulated via NK activity and increased the number of T cells and B cells. It helps immunodepressed host to level up quickly. However, further effective immunostimulation beyond the normal range could not be expected. A new combined method should be found to be immunopotentiated even for the uncompromized host. Recently, a new immunostimulant derived from streptococcus, OK-432, was widely used for the treatment of cancer in Japan. The cytostatic and cytotoxic actions of OK-432 for cancer cells have been made clear by in vitro and vivo study. It, however, is not clear as to how the developing immunostimulated states differ on the condition of admistering route, dosis or time-intlrval. In this series, the effects of intravenous administration of OK-432 as the host immunostimulator were compared with those of conventional subcutaneous administration
Expression in E. coli of finger-domain lacking tissue-type plasminogen activator with high fibrin affinity
AbstractTissue-type plasminogen activator (t-PA) has a high affinity for fibrin and induces lysis of fibrin (fibrinolysis) on the surface of fibrin without degrading circulating fibrinogen. cDNA for t-PA which lacks the ‘fingerdomain’ (the site for fibrin affinity) was isolated from Detroit 562 cells. Analysis of the nucleotide sequence revealed a lack of the sequences which code for the finger-domain. A plasmid (pDPAT 1) containing the Escherichia coli tac promoter/operator and the cDNA sequence coding for ‘finger-domain lacking t-PA’ was constructed for expression in E. Coli. The polypeptide so produced was a new type of t-PA lacking finger-domain, but revealed plasminogen activator activity with the function of fibrin affinity.Tissue-type plasminogen activatorFinger-domainFibrin affinityPlasmid E. coli tac promoter/operatorDetroit 562 cel
Sternal Resection and Reconstruction for Recurrence of Breast Cancer
We report 4 cases of sternal resection and reconstruction for para-sternal recurrence after radical mastectomy for breast cancer. All 4 had partial sternotomy combined with rib resection. Double Marlex mesh and muscular or myocutaneous flap were employed to close the sternal defect. Postoperative complications occurred in 2 cases : respiratory failure and partial skin necrosis. All patients are alive 12, 59, 77 and 117 months after sternal resection. Surgical management for parasternal recurrence after radical mastectomy can provide long-term survival and improve the quality of life of patients, especially those with solitary recurrences
Choriocapillaris flow deficit in a pachychoroid spectrum disease using en face optical coherence tomography angiography averaging
[Purpose] To investigate the choriocapillaris changes associated with pachychoroid pigment epitheliopathy (PPE) in comparison with healthy eyes. [Methods] Nine 3 × 3 mm macular optical coherence tomography angiography images were acquired in patients with PPE and age-matched healthy participants. Multiple en face image averaging of the choriocapillaris was binarized for quantitative image analysis of the flow voids. In PPE eyes, we evaluated the presence of pachyvessels and the association between the location of the choriocapillaris flow deficit and pachyvessels. [Results] Thirty-two eyes with PPE and 30 eyes of healthy participants were included. In PPE eyes, the mean total area (1.16 ± 0.18 vs. 0.91 ± 0.16, p < 0.001) and average size of the flow voids (790 ± 144 vs. 520 ± 138; p < 0.001) were significantly larger than those in control eyes. Composite images of the choriocapillaris and choroid showed choriocapillaris flow deficits just above and outside the pachyvessels. The mean proportion of the flow void area overlying the pachyvessels against the whole flow void area of the choriocapillaris was 21.3% ± 10.2% (9.38%-44.42%) in PPE eyes. [Conclusions] In PPE eyes, the blood flow area of the choriocapillaris decreased diffusely within the macular area compared to control eyes, and the choriocapillaris flow deficit was not necessarily related to pachyvessel location
カルボン酸の低摩擦特性に及ぼす分子配向の影響
Molecular alignment is a key to achieve an ultra-low friction coefficient. We found that friction coefficient decreased 49% when oleic acid (OAc) was added in poly-α-olefin (PAO), while only decreased 19% when added in polypropyleneglycol (PPG). FT-IR analysis indicates that the dimers of OAc became more easily aligned parallel to the sliding direction in PAO than in PPG. The associated carboxylic acids (OAc-PBAc), which feature two rings in the structure, an eight-membered cyclic carboxylic acid and a benzene ring, also decreased friction coefficient dramatically. FT-IR analysis indicates that the eight-membered cyclic carboxylic acid and the benzene ring were oriented parallel to the shearing plane. The oriented molecules led to low friction coefficient. Our results provide key insights into achieving ultralow friction coefficient through the design of the large, flat structures in lubricant molecules.本研究は、2017年度関西大学若手研究者育成経費(個人研究)において、研究課題「潤滑剤分子の配向によるスマート潤滑システムの創成」として研究費を受け、その成果を公表するものである。第22回関西大学先端科学技術シンポジウム関西大学千里山キャンパス100周年記念会館2018年1月18日(木)・19日(金
Accuracy, repeatability, and reproducibility of T1 and T2 relaxation times measurement by 3D magnetic resonance fingerprinting with different dictionary resolutions
[Objectives] To assess the accuracy, repeatability, and reproducibility of T₁ and T₂ relaxation time measurements by three-dimensional magnetic resonance fingerprinting (3D MRF) using various dictionary resolutions. [Methods] The ISMRM/NIST phantom was scanned daily for 10 days in two 3 T MR scanners using a 3D MRF sequence reconstructed using four dictionaries with varying step sizes and one dictionary with wider ranges. Thirty-nine healthy volunteers were enrolled: 20 subjects underwent whole-brain MRF scans in both scanners and the rest in one scanner. ROI/VOI analyses were performed on phantom and brain MRF maps. Accuracy, repeatability, and reproducibility metrics were calculated. [Results] In the phantom study, all dictionaries showed high T₁ linearity to the reference values (R² > 0.99), repeatability (CV 0.98), repeatability (CV < 6%), and reproducibility (CV ≤ 4%) for T₂ measurement. The volunteer study demonstrated high T1 reproducibility of within-subject CV (wCV) < 4% by all dictionaries with the same ranges, both in the brain parenchyma and CSF. Yet, reproducibility was moderate for T₂ measurement (wCV < 8%). In CSF measurement, dictionaries with a smaller range showed a seemingly better reproducibility (T₁, wCV 3%; T₂, wCV 8%) than the much wider range dictionary (T₁, wCV 5%; T₂, wCV 13%). Truncated CSF relaxometry values were evident in smaller range dictionaries. [Conclusions] The accuracy, repeatability, and reproducibility of 3D MRF across various dictionary resolutions were high for T₁ and moderate for T₂ measurements. A lower-resolution dictionary with a well-defined range may be adequate, thus significantly reducing the computational load. [Key Points] • A lower-resolution dictionary with a well-defined range may be sufficient for 3D MRF reconstruction. • CSF relaxation times might be underestimated due to truncation by the upper dictionary range. • Dictionary with a higher upper range might be advisable, especially for CSF evaluation and elderly subjects whose perivascular spaces are more prominent
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