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Volcanic plumes from small and moderate eruptions represent a challenge in the study of plume morphology due to eruption source parameter uncertainties and atmospheric influence. Sakurajima volcano, Japan, features such activity and due to its continuous eruptions in the recent years provides an ideal natural laboratory. A data set of 896 eruptions between 2009 and 2016 with well‐constrained plume heights, estimated erupted mass, and associated atmospheric conditions has been compiled. Plume heights ranged between 1,500 and 5,000 m and mainly developed under stable atmospheric stratification and low background wind speeds. The eruptions presented in the database were used to drive FPLUME, a 1‐D integral volcanic plume model, to study the simulated plume morphology. FPLUME was seen to provide consistent results under stable atmospheric stratification. A method for the real‐time monitoring of erupted mass used in the Sakurajima observatory was seen to provide appropriate first guess estimates for the eruptions, showing agreement with analytical and simulated mass flow rate calculations. Volcanic plumes from Sakurajima show significant influence by the atmospheric environment. The plume scaling parameter (Π) was used to characterize the expected degree of plume bending with results correlating well against modeled plume angles. The vertical wind profile was seen to have a significant impact on the resolved plume. Wind shear characteristics were seen to have a mechanical effect on the plume, aiding or inhibiting bending. Finally, potential issues were identified in simulations under unstable atmospheric conditions as the model either failed to provide a solution or overestimated the plume height. A database of 896 eruptions from Sakurajima with associated atmospheric profiles is presentedDifferent plume bending regimes are quantitatively evaluated using the FPLUME modelVertical wind shear mechanically affects plume morphology by aiding or inhibiting plume bending

We recorded volcanic lightning generated by Vulcanian explosions at Sakurajima Volcano using a synchronized multiparametric array. Physical properties of lightning are related to plume dynamics, and associated electromagnetic field variations are revealed by video observations (high speed and normal speed) together with infrasound and high sampling rate magnetotelluric signals. Data show that volcanic lightning at Sakurajima mainly occurs in the plume gas thrust region at a few hundred meters above the crater rim, where the overpressure of the turbulent volcanic jets determines the electrification of particles generating a complex charge structure in the growing plume. Organization of charges may be achieved at later stages when the plume transitions from the jet phase to the convective phase. Comparison with atmospheric sounding and maximum plume height data show that the effect of hydrometeors on flash generation at Sakurajima is negligible and can be more prudently considered as an additional factor contributing to the electrification of volcanic plumes. Systematic multiparametric observations of volcanic lightning are presented for the first timeTurbulent jets cause ash charging and clustering, promoting early plume electrical dischargesVent discharges are not influenced by atmospheric conditions and are relevant for early warning

We present a method for classification of the two distinct types of electrical activity that occur during an explosive volcanic eruption: vent discharges and lightning. Vent discharges occur at the onset of an explosion and create a distinctive radio frequency signature called continual radio frequency. Seconds to minutes after the onset of the eruption, lightning begins to occur throughout the eruption column. We use logistic regression to classify a radio frequency impulse as being part of either a lightning flash or a period of continual radio frequency. The classifier uses the number of peaks in the amplitude envelope from 1 ms windows before and after the impulsive very high frequency waveform, with an average accuracy of 97.9%. We propose that this method could be used in an algorithm to determine when explosive eruptions occurred by identification of the distinctive signatures of vent discharges and lightning. We present a method for automated identification of two distinct types of electrical activity from explosive volcanic eruptions. Explosive eruptions produce lightning, just like thunderstorms. In addition, they also produce small (<4 m) spark‐like electrical discharges at the vent of a volcano, which are called vent discharges. These vent discharges occur for relatively long durations compared to the duration of a typical lightning flash (seconds vs. hundreds of milliseconds) and are thus easily distinguishable in very high frequency (30–300 MHz) electric field measurements. We use logistic regression to classify an electric field impulse as either being part of a lightning flash or a vent discharge. The classifier uses the number of peaks in the electric field signal in 1 ms time windows before and after an electric field impulse. The accuracy of the classifier is 97.9%. We explain that the classifier could be used on a low‐power lightning sensor to automatically identify that an explosive eruption had occurred. We discuss how this capability would enable a new era of volcanic lightning monitoring that would allow for new research into understanding the physical mechanisms of vent discharges to learn how they can be used during the response to an eruption. We created a logistic regression model that classifies electrical activity as either vent discharges or lightning with an accuracy of 97.9%The logistic regression model uses the number of waveform peaks in 1 ms time windows preceding and succeeding an RF impulseThe model could be used to identify the characteristic pattern of electrical activity produced by explosive eruptions We created a logistic regression model that classifies electrical activity as either vent discharges or lightning with an accuracy of 97.9% The logistic regression model uses the number of waveform peaks in 1 ms time windows preceding and succeeding an RF impulse The model could be used to identify the characteristic pattern of electrical activity produced by explosive eruptions

The effects of topography and atmospheric structures on infrasonic wave propagation from a volcanic source were investigated using observations and numerical modeling. This paper presents the first long‐term observational data set showing spatiotemporal variations in patterns of infrasound propagation at distances of up to 60 km from a persistently active infrasound source (Sakurajima Volcano, Japan). The data show that the amplitudes of infrasonic waves received at distant stations relative to those received at a reference station close to the source can vary up to an order of magnitude over short time intervals and short distances and that they do not follow the theoretical geometric decay expected for homogeneous media. Moreover, waveforms also change significantly in both time and space. Numerical simulations were performed using a two‐dimensional finite difference time domain (2‐D FDTD) method. Effects of atmospheric structure and topography are included in a vertical section parallel to the wave propagation direction. The simulation successfully reproduced the variations of amplitudes and waveforms. Results are interpreted in terms of wave refraction due to sound and wind speed gradients and wave diffraction at topographic barriers. Our numerical results indicate that both atmospheric and topographic propagation effects are nonnegligible. To evaluate the propagation effects and determine source processes in spatially and temporally varying infrasound data, atmospheric data with a time resolution higher than is currently available are required. If the data are available, the present results suggest that the propagation effects could be evaluated using 2‐D FDTD modeling at realistic calculation times. A long‐term data set spatial‐temporal infrasound propagation is presentedNumerical modeling with atmosphere and topography explains the observationThe propagation effects are non‐negligible and can be evaluated by our model

AbstractIn materials refining processes such as steelmaking process, bath-entry of agents such as CaCO3attracts career gas around their entire surface so that the dispersion in the bath can be inhibited. To shed light on the still vague instant phenomenon, this study employs a water model experiment and carries out the visualization. Therefore, this study visually demonstrates the growth and rupture of air cavity due to water entry of horizontal superhydrophobic circular cylinders with the aid of a high-speed camera. Here, we show that the water entry of the horizontal hydrophobic cylinder forms a film of cavity behind the cylinder whereas a hydrophilic cylinder forms a cavity from both ends of the cylinder. In a high Froude number entry, once the cavity film ruptured on both sides of it, the contact lines of the cavity film abruptly move along the surface of the cylinder. In a low Froude number entry, the influence of weak fluid inertia force makes several ruptures on the cavity film which grow individually and split off the cavity. Of a particular interest is the fact that the multi-rupture regime appeals for the spanwise three-dimensionality on the cavity film against the previous studies within two-dimensional treatment. Furthermore, this report finds the trend for some range of Fr that the nondimensionalized closure depth of the cavity film zcwith diameter of the cylinder obeys zc/d∼ Fr1/3in the range 4.7 ≤ Fr ≤ 40 although it depends on Fr in the water-entry problem of a hydrophobic sphere.

AbstractThis paper aims to computationally investigate flow patterns of gas-liquid two-phase with an abrupt expansion. To do so, the present computation is nicely verified against the previous experimental results for a good wettability surface. These rectangular channels have a thickness narrower than the Laplace constant of the present situation. Under a poor wettability condition, this narrow thickness affects the flow pattern; e.g., the air phase forms channeling behind the expansion in a low airflow rate whereas the air phase becomes fragments of bubbles due to the expansion under a good wettability condition.

Bacterial cellulose (BC) pellicles obtained from an Acetobacter xylinum culture were disintegrated using mechanical methods to be used as reinforcement to produce biocomposite sheets with Apple and Radish Pulp. The nanosize disintegrated BC pellicles were blended with microsize apple and radish pulp in the wet state and then hot pressed to produce paper-like sheets.

BACKGROUND AND STUDY AIM: We have previously reported that gastric ulcers artificially created by endoscopic submucosal dissection (ESD) would heal within 8 weeks regardless of size and location. The details of the healing process remain unclear, and we aimed to clarify the mechanism by histopathological investigation. PATIENTS AND METHODS: 21 post-ESD ulcers were examined histopathologically, using surgically resected specimens from patients who had subsequently undergone gastrectomy due to submucosal invasion and/or lymphovascular infiltration by the tumor. The grade of ulcer, appearance of regenerative mucosa, scar formation, and extent of fibrosis were evaluated. RESULTS: Fibrosis and wall thickening were observed from 2 weeks after ESD, but regenerative mucosa was not observed until 5 weeks. Among 12 patients who underwent gastrectomy later than 8 weeks after ESD, a mucosal defect was still observed in two patients. In these two patients the lesion was associated with severe fibrosis due to previous peptic ulcer or submucosal invasion by the lesion. CONCLUSION: Size reduction in these ulcers occurs by contraction in the early phase, then regenerative mucosa covers the remaining mucosal defect within 8 weeks. If there is fibrosis under the lesion before ESD, there is a possibility that the artificially created ulcer will not heal within 8 weeks.

Maxacalcitol, the 22-oxa-derivative of 1α,25-dihydroxyvitamin D3 and used currently as an antihyperparathyroidism and antipsoriatic drug, has been synthesized in seven chemical steps from 1α-hydroxydehydroepiandrosterone on the basis of our previously developed route. The present synthesis allows the production of the protected form of the penultimate intermediate in 26% overall yield in a kilogram scale reaction employing neither difficult reaction conditions nor chromatographic purification, having overcome all the difficulties involved in the previous route.

A numerical analysis and a water model study of the mold region of a billet continuous caster was performed with a novel injection concept using swirling flow in the pouring tube, to control the heat and mass transfer in the continuous casting mold. The following results were found:

Abstract:  Most particle-tracking velocimetry (PTV) algorithms are not suitable for calculating the velocity vectors of a fluid flow subjected to strong deformation, because these algorithms deal only with flows due to translation. Accordingly, it is necessary to develop a novel algorithm applicable to flows subjected to strong deformations such as rotation, shear, expansion and compression. This paper proposes a novel particle tracking algorithm using the velocity gradient tensor (VGT) which can deal with strong deformations and demonstrates that this algorithm is applicable to some basic fluid motions (rigidly rotating flow, Couette flow, and expansion flow). Furthermore, the performance of this algorithm is compared with the binary image cross-correlation method (BICC), the four-consecutive-time-step particle tracking method (4-PTV), and the spring model particle tracking algorithm (SPG) using simulations and experimental data. As a result, it is shown that this novel algorithm is useful and applicable for the highly accurate measurement and analysis of fluid flows subjected to strong deformations.

Abstract: α2HS-Glycoprotein (HS), a crystal surface binding substance extracted from human urine, is considered to be one of the urinary macromolecular inhibitors in urolithiasis. In the present study, reverse transcription–polymerase chain reaction was used to examine HS mRNA expression, and immunohistochemical staining was used to reveal its localization in the human kidney. The inhibitory effects of recombinant human HS and native human HS on calcium oxalate crystal growth were examined in a seed crystal system. HS mRNA was found to be expressed in the human kidney, and it was located in the epithelial cells of distal and proximal renal tubular cells. However, neither recombinant HS nor native HS had an inhibitory effect on crystals in the protein concentration of urine of healthy humans. HS in the urine, therefore, does not seem to be a potent inhibitor in stone formation.

Bone morphogenetic protein (BMP)-2 has the capacity to induce the neuronal differentiation of PC12 cells. Unlike nerve growth factor, however, BMP-2 failed to induce the activation of the 41-/43-kDa mitogen-activated protein (MAP) kinase pathway in these cells. In contrast, BMP-2 characteristically induced the sustained activation of the p38 MAP kinase pathway. Pretreatment of PC12 cells with SB203580 inhibited the BMP-2-induced neurite outgrowth formation in a dose-dependent manner; this inhibition coincided well with the ability of SB203580 to inihibit the BMP-2-induced activation of the p38 MAP kinase pathway. Overexpression in PC12 cells of wild-type MAP kinase kinase (MKK)-6 enhanced the BMP-2-induced activation of p38 MAP kinase, whose activation correlated well with the ability of these cells to induce neurite outgrowth in response to BMP-2. Transient expression of kinase-negative forms of MKK3/6 inhibited the formation of neurite outgrowth in response to BMP-2. Furthermore, expression of constitutively active forms of MKK3/6 induced neurite outgrowth without BMP-2 stimulation, and SB203580 inhibited this induction. These results clearly indicate that activation of the p38 MAP kinase pathway is necessary for BMP-2-induced neuronal differentiation of PC12 cells. Our results also suggest that activation of the p38 MAP kinase pathway alone can induce the neuronal differentiation of PC12 cells.

Abstract:  A new algorithm of Delaunay Tessellation Particle Tracking Velocimetry (DT-PTV in abbreviation) is proposed for tracking particles in images of a PIV system by making use of the Delaunay tessellation (DT). The algorithm is tested by using numerically simulated particle images. The calculation results based on DT are compared with those obtained by a conventional algorithm of Binary Image Cross-correlation method (BICC). The new algorithm shows higher performance of obtaining more identical particles in two consecutive images correctly with shorter computation time even if the images contain many particles. A further application of DT to elimination of spurious vectors is also discussed.

Various composite samples reinforced with polyoxymethylene (POM) whisker crystals were prepared and their Young's moduli were measured and analysed, on a theoretical equation, to estimate the modulus of the filler itself. Good reinforcement was obtained with matrix resins such as an epoxide and an unsaturated polyester, the results giving the modulus of the whisker to be approximately 1×1011 N m-2, i.e., almost equivalent to the ideal crystal modulus of POM. Some acoustic properties were investigated for sheet composite materials prepared with a polyolefin polymer for matrix. The sonic velocity attained was more than twice that of the matrix polymer, at larger filler contents, while the internal dynamic loss was maintained at a reasonably high level. Loudspeakers carrying diaphragms of the composite sheets showed improved frequency characteristics in the high-frequency region. Some morphological observations were made for the crystals embedded in resins.

We have developed a new assay technique using high-performance liquid chromatography. The assay was performed at a flow rate of 0.7 ml/min, a temperature of 60°C and an ultraviolet absorption of 214 nm. Comparison of the results of the new assay with the results obtained for identical samples using the conventional fluorometric method demonstrated a very high correlation coefficient of 0.931.

Exposure of bladder tumor cell strain HT-1197, chronic bonemarrow leukemic cell strain K-562, and African green-turtle normal kidney cell strain Vero to high energy shock waves resulted in ultrastructural changes and a reduction in cell viability as determined by 3H-thymidine incorporation assay and flowcytometer. K-562 was the most sensitive while Vero was the most resistant to the high energy shock wave. By flowcytometry using anti BrdU antibody, described K-562 in the S phase was found to be inhibited by the exposure. Electron microscopy revealed destruction of microvilli over the cell surface and swollen mitochondria in K-562 and HT-1197. These effects were related to the number of high energy shock wave exposures. Our study demonstrates that a high energy shock wave has an anti-tumor effect in vitro.

High-performance liquid chromatography (HPLC) monitoring with an ultraviolet detector was carried out to measure urinary oxalate levels in urolithiasis. Interfering substances in urine were removed by anion exchange prior to chromatography. This procedure was found excellent with respect to sensitivity, reproducibility, and analytical recovery. The findings were in agreement with colorimetric date. The mean oxalate level in 24-hour urine was 30.5±15.1 mg in patients with a single episode and 36.3±9.8 mg in recurrent stone formers. The latter values was significantly higher than the normal control level (27.4±3.8 mg).

As a result of extensive research and development in several countries, the technologies of magnetic suspension and linear electric drives are becoming available for transportation applications. The successful demonstration and operation of prototype vehicles has established the technical viability of these systems. Several urban transit or shuttle services, with magnetic suspension and/or linear motor propulsion are likely to be operational within 3-4 years. After the final stages ofdevelopment and rigorous testing, high speed systems are likely to be an option for intercity implementation by the end of the decade. This paper presents a report on the worldwide status of R&D and test programs of non-contact suspension and propulsion technology for guided ground transport.

Anodic processes were studied for eugenol, isoeugenol and 2,6-dimethoxy-4-allylphenol by cyclic voltammetry at a glassy carbon electrode in methanol. Preparative electrolyses were also applied coulometrically to these phenols, followed by the separation and the determination of the structures of -e, -2e and -4e products. It was indicated that both radical and cationic reactions were controlled by the applied potentials, the solvent media and the substituents on the aromatic rings.

A sheet obtained from bacterial cellulose had a remarkably high modulus of elasticity as reported in Part 1 of this series. The Young's modulus of a sheet prepared by squeezing and drying a gel-like pellicle of bacterial cellulose was found to be > 15 G Pa. In addition, it has been found that treatment of the gel-like pellicles or dried sheets of bacterial cellulose with alkaline and/or oxidative solutions improves the mechanical properties significantly, and the Young's modulus of the resulting sheets approaches 30 G Pa. In this paper, improvement of the mechanical properties of bacterial cellulose sheets by the removal of impurities is investigated and the applicability of bacterial cellulose to diaphragms of electroacoustic transducers is discussed.

In order to develop a non-isotopic quantitative assay of erythropoietin (Epo) receptor (EpoR) on human cells, we devised a flow-cytometric assay using cells stained with biotin-labelled and a streptavidine–RED670 conjugate. For quantification, we applied the Kolmogorov-Smirnov test and calculated the D value. The D value was evaluated from the degree of shift in two profiles according to the increase of fluorescence intensity due to the specific binding of biotin-labelled Epo to EpoR. A good correlation was observed between the number of EpoR calculated by 125I-Epo binding assay and the D value. Then, EpoR expression on bone marrow cells from normal individuals was studied by three-colour flow cytometry. In normal bone marrow, the number of EpoR on cells was highest in CD34+CD38− cells (approximately 1600 sites/cell), and decreased in the following order: CD34+CD38− cells > CD34+CD38+ cells > CD34−CD38+ cells. Glycophorin A (GpA) positive erythroid cells also expressed EpoR, and their CD34+ fraction expressed more EpoR than their CD34− fraction. However, the expression levels of EpoR of these fractions were lower than CD34+CD38− cells. These results indicated that EpoR was highly expressed on CD34+ haemopoietic progenitors from very early stages of differentiation without expression of CD38 antigen, and that the level of expression decreased with erythroid differentiation as well as with various lineage commitment in human bone marrow cells.

The effects of papaverine, a smooth muscle relaxant agent, on the voltage-dependent Ca++ current were examined in isolated smooth muscle cells from the guinea pig trachea. The tight-seal whole cell voltage clamp technique was used. Papaverine (1-100 microM) inhibited the Ba++ inward current (IBa) through the voltage-dependent L-type Ca++ channel in a concentration-dependent fashion. The inhibitory effect of papaverine on IBa appeared to have both tonic and use-dependent components. In addition to the reduction of the maximal conductance of IBa, papaverine (20 microM) shifted the quasi-steady-state inactivation curve of IBa to more negative membrane potentials by approximately 10 mV. These effects of papaverine on IBa were completely reversible. Although it has been suggested that papaverine inhibited phosphodiesterase to increase intracellular cyclic AMP, phosphodiesterase inhibitors (theophylline, 500 microM, and 3-isobutyl-1-methylxanthine, 500 microM), isoproterenol (2 microM) and dibutyryl cyclic AMP (1 mM) did not affect IBa. Thus, papaverine inhibits IBa in a way independent of intracellular cyclic AMP. Papaverine also had inhibitory effects on other membrane currents (i.e., the voltage-dependent transient outward K+ current and the Ca(++)-activated oscillatory K+ current), which may result in an enhancement of the excitability of the cells. These results suggest that inhibition of the voltage-dependent L-type Ca++ channel is involved in the papaverine-induced relaxation of the tracheal smooth muscle.

A preliminary experiment has shown that a sheet-shaped material prepared from bacterial cellulose has remarkable mechanical properties, the Young's modulus being as high as >15 GPa across the plane of the sheet. The mechanical properties were little affected by the fermentation conditions of pellicles and the preparation conditions of the sheets, i.e. the pressing and drying of pellicles. From structural investigations, the high Young's modulus has been ascribed to the unique super-molecular structure in which fibrils of biological origin are preserved and bound tightly by hydrogen bonds. It has also been found that a “pulp” obtained from bacterial cellulose gives a strong paper and is useful for reinforcing conventional pulp papers and enabling paper-making from some fibrous materials.

Uniformly ground Sm2Fe17Nx fine powders with high-performance permanent magnetic property and oxidation resistance characteristics were obtained from the coarse powders by ball milling in an organic solution containing a surfactant and surface modification for them, followed by fabrication of their bonded magnets. Their remanence (Br) and coercivity (Hcj) values were well-balanced and considerably higher than those for the samples prepared by conventional methods, and a huge maximum energy product (BH)max around 330 kJ m^-3 was consequently attained as a reproducible average. The Sm2Fe17Nx powder stabilized by surface coating with the zinc metal produced via photodecomposition of diethylzinc (Zn(C2H5)2) showed the better oxidation resistivity than the uncoated samples, so that the Br, Hcj, and (BH)max values were maintained at high levels even after the heat treatment at 353−423 K for several hours as required to cure epoxy resin bonded magnets. The bonded magnets prepared from the Zn/Sm2Fe17Nx powders provided the highest (BH)max value (~176 kJ m^-3) among the values reported up to date, even after exposure to air, and their irreversible flux loss was also smaller than that of the uncoated one.

From the investigation of the dietary intake and habits of male Japanese renal stone patients we established several general guidelines. Fluid intake should be increased, especially after dinner. Unbalanced diets should be corrected and avoided (the diet should include different types of food, with vegetables being eaten at every meal and an excessive intake of meat should also be avoided). Three meals a day should be eaten and an excessive intake at dinner should be avoided. The interval from dinner until retiring should be extended. By following these individual dietary guidelines the stone recurrence rate in 199 male calcium stone patients who had received individual dietary instruction decreased remarkably compared to that in male calcium stone patients who had not received individual dietary instruction, not only during the period of outpatient visits but also after outpatient visits were discontinued. From these results we conclude that individual dietary management should be the primary measure for the prophylaxis of renal stone disease in Japan.

Application of advanced control technology based on microcomputer technology to motor vehicle has become of major interest to automotive control engineers. Active control technology such as active suspension and four wheel steering is changing the design concept of motor vehicle dynamics and will improve vehicles by making them easier to handle, higher in performance and safer to drive.

In a previous study we showed that the magnesium-calcium ratio of tap water is negatively correlated with the incidence of calcium-containing urinary stones. In this study we examined the relationship between the incidence of struvite stones, water hardness and the regional geological features on the basis of our previous study and an epidemiological study of urolithiasis performed in Japan. The magnesium-calcium ratio of tap water was found to correlate positively with the incidence of struvite stones. The tap water magnesium-calcium ratio was high in regions of basalt and sedimentary rock and was low in granite and limestone areas. The incidence of struvite stones in the regions of basalt and sedimentary rock was higher than that in the granite and limestone areas. Thus, this study suggested that the incidence of struvite stones is related to the magnesium-calcium ratio of tap water and to the regional geology, as is the case for calcium-containing stones.

Ninety-seven male patients with idiopathic calcium urolithiasis and 17 normal male subjects were studied to evaluate the mechanism of idiopathic hypercalciuria with an oral calcium tolerance test, which has been useful in differentiating hypercalciuria. The changes in parathyroid function, such as parathormone and urinary cyclic AMP, and calcium after calcium load differed between absorptive hypercalciuria and renal hypercalciuria. We have confirmed that the change in serum calcitonin after calcium load was also different in these two hypercalciurias. The increase in serum calcium was sufficient to reduce parathyroid function but serum calcitonin was unchanged after calcium load in the control group, in patients with normocalciuria, and those with renal hypercalciuria. Although serum and urinary calcium were more elevated in absorptive hypercalciuria than in the other three groups, parathyroid function was not significantly reduced after loading in absorptive hypercalciuria. In this group only, the serum calcitonin was significantly elevated after calcium load. It is reasonable to suggest that, in this group, because parathyroid function is usually suppressed by intestinal hyperabsorption of calcium, parathyroid function may not be further suppressed by even calcium load. Possibly the significant stimulation of calcitonin may compensate for the lack of suppression of parathyroid function and maintain normal serum calcium levels in absorptive hypercalciuria. These results suggest that the change in serum calcitonin is also useful to differentiate abnormalities of calcium metabolism in patients with hypercalciuria.

The thermal accretion (or mushroom) which is formed around the tuyere in steelmaking plants was simulated by a cold model and its formation process was observed. Single- and multi-hole nozzles were used for gas injection. The multi-hole nozzle was an artificial mushroom-like nozzle. The bubble and flow characteristics were investigated using an electrical resistivity probe and the laser Doppler velocimeter system. The process of thermal accretion formation consists of the following three stages: (1) generation of a core; (2) separation of the core and regeneration of another core; and (3) steady growth of the accretion. The shape of the thermal accretion and the bubble characteristics changed with each stage, depending on the thermal conductivity of the material of the nozzle. The bubble and liquid flow characteristics for the multi-hole nozzle were examined in comparison with those for the single-hole nozzle. The following results were obtained: (1) the bubbling jet generated by the multi-hole nozzle spread more widely in the radial direction than that generated by the single-hole nozzle; and (2) the circulation flow rate for the former nozzle was 33% larger than that for the latter nozzle.

PurposeWe previously suggested that osteopontin (OPN) plays an important role in the process of deposited calcium crystals adhesion to cells in the early stages of urolithiasis. To further confirm this theory, we tried to inhibit OPN expression at the translational level and examined its cellular biological consequence on the formation and adhesion process of crystals.Materials and MethodsWe synthesized antisense and sense oligonucleotide corresponding to an appropriate part of the coding sequence for OPN in Madin Darby canine kidney (MDCK) cells. With the aid of lipofection reagent DOTAP, antisense and sense oligonucleotide introduced into MDCK cells grown in a confluent monolayer. After further incubation, inhibition of OPN expression in the cells was assessed by immunofluorescence photomicrography, and formation of calcium oxalate crystals was quantitated by incorporation of45 Ca into the stone and visualized by scanning electron microscopy (SEM).ResultsAntisense oligonucleotide at concentrations higher than 20 micro M inhibited synthesis of OPN. Incorporation of45 Ca into the calculus stone was inhibited by the addition of oligonucleotide in a concentration dependent manner in a range above 20 micro M. More than 90% of incorporation was inhibited at 50 micro M as compared to control. Inhibition of calcium crystal formation was confirmed by SEM.ConclusionsOPN was shown as a major component in the extracellular matrix involving the formation and adhesion of calcium crystals in the distal renal tubular cells, suggesting that OPN plays an important role in stimulating deposition and adhesion of calculus crystals to cells in the early stages of urolithiasis.