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Background In some treatments using multiple dental implants, the implants are inserted in the bone with splinted or non-splinted implant prostheses. There are some reports about the influence of the splinted and non-splinted implants on stress distribution in the bone using the finite element method (FEM), and there is a controversy in the literature regarding whether the splinted or non-splinted implants prostheses reduce the stress generated on the implant-surrounding bone more efficiently. Additionally, the simple shape of the jaw bones with limited bone area was used for FEM analysis in many studies at the expense of accurate analysis. Objective The aim of this study was to evaluate the difference in stress distribution in the bone between the splinted and non-splinted implants, and between completely and partially edentulous mandibles. Methods The implants were inserted in the first premolar, second premolar, and first molar regions of the partial and complete mandibles, and the splinted and non-splinted crowns were attached to the implants. Vertical load (100 N) or oblique load (70 N, 30° from its long axis towards the lingual) was applied on the first premolar. Results When vertical load was applied to the partially edentulous mandible model, the stress was concentrated intensively on the cortical bone around the first premolar regardless of whether splinted or non-splinted implants were used. On the other hand, the vertical load applied to the completely edentulous mandible model caused the stress to be concentrated intensively on the cortical bone around the first premolar with non-splinted implants. With respect to the oblique load, the stress was concentrated intensively on the cortical bone around the first premolar only with the non-splinted implants, in both the partial and complete mandibles. Conclusion This study shows the different stress distributions of the cortical bone around the implants between the partial and complete mandible. This indicates that the complete mandible should be used for the analysis of bone stress distribution around the implants using FEM.

Conventional insulated gate bipolar transistor (IGBT) current sensing and protection techniques usually employ discrete sensors, such as lossy shunt resistors, and may involve accessing the high-voltage collector load of the IGBT. This would normally present difficulties for integration. This paper presents an IGBT gate driver IC with a collector current sensing circuit and an on-chip CPU for local data processing. This IC is prototyped using a TSMC 0.18 μm 40 V BCD Gen-2 process. The collector current sensing technique is based on the unique Miller plateau relationship between the gate current and collector current ( $I_{C}$ and $I_{G}$ ) for a particular gate resistance ( $R_{G}$ ). It allows a cycle-by-cycle measurement of IC during both turn- on and turn- off transients without any extra discrete components. The temperature variation is compensated internally by the on-chip CPU using polynomial curve fitting. This technique only monitors the low-voltage signal at the gate terminal, without the need to handle any high-voltage signal on the collector/load side. Measurements using a double pulse test setup show an accuracy of ±0.5 A over the current ranges of 1–30 A for turn- on and 1–50 A for turn- off from 25 to 75 °C.

The application of a segmented gate driver (SGD) to detect aging and provide automated compensation for SiC MOSFETs is presented. By dynamically modifying the gate resistance during switching transients, we can stretch the Miller plateau (MP) duration. The MP level is used as an indicator for the health condition of the SiC power MOSFET. A digital control circuit analyzes the aging effect and provides a control signal to an integrated boost converter, which powers the gate drive voltage. In this manner, the gate drive voltage can be adjusted to compensate for changes in the MOSFET performance. The same SGD can also be used to suppress gate ringing to protect the SiC power device against over/undershoot damage. This is of particular importance at elevated gate voltage.

To suppress excessive gate voltage swings during switching, a resistance is normally used to limit the charging rate of the gate capacitance (C G ). Modern solutions, such as segmented gate drivers, can be used to dynamically control the gate resistance R G to minimize ringing while maintaining the fast-switching speed of the transistor. The timing or dynamic pattern of the gate resistance is critical in the optimization of the device and circuit performance. Traditionally, this gate drive pattern is obtained via a trial-and-error or iterative procedure. This paper proposes a method to automatically determine the timing intervals by monitoring the gate signal (V GATE ) through slope sensing with analog filter and subsequent mixed-signal processing. The output timing indicator (T SEG ) is then fed back to the segmented gate driver IC to achieve automatic adjustments of the dynamic driving pattern. The proposed system is able to determine the optimum T SEG for dynamic gate driving. For the SiC power MOSFET used in our testing, segmented R G driving between 2.5 and 10 Ω does not hinder the switching speed, while keeping the undershoot of the SiC module to be within 1 V or 5% of the total applied gate voltage.

In this paper, an IGBT gate driver IC with a collector current sensing circuit and an on-chip CPU for digital control is presented. The IC is fabricated using TSMC's 0.18 μm BCD Gen-2 process. This technique is based on the unique Miller plateau relationship between the gate current and collector current (I g and I C ) for a particular gate resistance (R g ), and allows for a cycle by cycle measurement of I C during both turn-on and turn-off transients. Together with a dedicated and simple on-chip stack-based CPU, this technique can potentially provide collector current regulation without any extra discrete component. This technique only monitors the low voltage signal at the gate terminal, without the need to handle any high voltage signal on the collector/load side. Measurements have been carried out using a double pulse test setup. An accuracy within ±1 A is achieved over the current ranges between 1 to 30 A for turn-on and 1 to 50 A for turn-off.

To obtain the accurate magnetic properties of Nd-Fe-B sintered magnets with high coercivity (HcJ), we have compared a pulsed-field magnetometer (PF) method with a hysteresis graph (HG) method using an extra large-sized electromagnet. To prevent the effects of machining on magnetic properties in small samples when making measurements of the accurate hysteresis and demagnetization curves, cylindrical samples used in the experiment were kept at a constant common diameter of 10 mm. This was necessary to correct the demagnetizing field and the effect of eddy current for the PF and the magnetization distortion for the HG methods. Reliable calibrations and corrections of the magnetization and the magnetic field were very important. Furthermore, it was essential that the longer length (L) of the sample be magnetized uniformly for both the methods. To correct the demagnetizing field and obtain exact differential susceptibility near HcJ, L of the sample had to be more than 14 mm for the PF method. Because the saturation magnetization of the Nd-Fe-B sintered magnet was almost equal to that of the cast anisotropic AlNiCo magnet, the correction of magnetization distortion for the HG method using the AlNiCo magnet of L = 21 mm, which was the same size of the sample, was most suitable in the experiment compared with the other conditions.

We prepared single-electron tunnelling (SET) transistors made of Fe nanodots and investigated their fundamental properties. The device films were composed of Fe nanodot arrays embedded in a SrF 2 matrix fabricated by the co-evaporation method on thermally oxidized Si substrates. The Si substrates were used as backgate electrodes. The current-to-voltage curves between source and drain electrodes were nonlinear even at room temperature. Coulomb blockade was clearly observed at 8 K. Current oscillation which is another SET characteristic was confirmed in the curves of drain current versus gate voltage. The oscillation period was roughly estimated to be about 20–40 V.

The relationship between the temperature coefficient of coercivity {α(HcJ)} and the ratio Sv to HcJ was investigated for M-type Sr-ferrite substituted by La and Co (Sr1-xLaxFe12-xCoxO19) in the temperature range from 173to 423 K, where Sv and HcJ were the magnetic viscosity constant, which essentially determined the thermal stability, and the coercivity, respectively. The value of x was varied between 0, 0.3, and 0.6. The value of α(HcJ) for x = 0 with Sv/HcJ = 0.038 was 0.35%/K, whereas that for x = 0.3 with Sv/HcJ = 0.034 was 0.1%/K at 298 K. Furthermore, α(HcJ) for x = 0.6 with Sv/HcJ = 0.026 was almost zero at 298 K. The following relation of α(HcJ) to Sv/HcJ was also found to hold in these M-type Sr-ferrite magnets substituted by La and Co, as in the case of Nd-Dy-Fe-Al-B-Sn sintered magnets. α(HcJ) was expressed as {28.5k − (δE/δT)H}/kT ·(Sv/HcJ), where, k, E, T, and H were the Boltzmann constant, the activation energy, the absolute temperature, and the magnetic field, respectively. The equation shows that smallerSv/HcJ values are necessary for ensuring small α(HcJ) values, which are very important for permanent magnets.

The authors demonstrated experimentally an influence of power supply noise on the magnetic field sensing of a high-frequency carrier-type magnetic field sensor. In magnetic sensing using such a magnetic sensor, an external ac magnetic field signal is modulated in amplitude in accordance with a high-frequency carrier signal. When a switching power supply is used for the carrier signal circuit, the power supply noise is also modulated in amplitude by the carrier signal. Therefore, both the upper and lower sideband spectra in the vicinity of the carrier signal are due not only to the magnetic field component but also to the power supply noise component. The sensitivity and frequency bandwidth of magnetic field sensing depend strongly on the noise level and noise frequency of the switching power supply.

The experiment was carried out to investigate the effect of changing mole ratio, n (= Fe3+/Co2+), and pH conditions on magnetic and physical properties of Co ferrite prepared by the chemical coprecipitation method without post-annealing. The chemical coprecipitation compositions were chosen according to the formula (CoO)·n/2(Fe2O3), where n varied between 2.0 and 3.5. Optimum magnetic properties were achieved with materials of composition (CoO)·1.375(Fe2O3). The typical magnetic and physical properties are saturation magnetization σs = 61.6×10-6 Wb·m/kg (49.0 emu/g), coercivity HcJ = 255 kA/m (3.21 kOe), lattice constant a = 0.8391 nm, and average particle size D = 23 nm, anisotropy constant K1 = +2.7×104 J/m3 (+2.7×105 erg/cm3), K2 = −13.0×104 J/m3 (−13.0×105 erg/cm3), anisotropy field HA nearly equals 3 MA/m (37.7 kOe). The rotational hysteresis integral Rh, which is related to the magnetization mechanism of these fine particles, is 1.32, and it was found that the magnetization mechanism is an incoherent one.

This letter describes a power supply module with an ultrathin, high-efficiency switching dc-dc converter system in order to meet increasing demand for smaller, thinner and lighter devices in portable electronic equipment. Usually, the inductor is the largest passive components in a converter system. We formed inductors on ferrite wafers as a substrate to mount an IC chip using thin film technology. This realized a significantly small and thin module. The external size of the module is 3.5 mm /spl times/ 3.5 mm /spl times/ 1.0 mm. Its maximum output power is 1 W, and its efficiency is up to 93.4%. A high power density of 81.6 W/cc was realized.

The effect of magnetic field on the velocity distribution function of tritons in D-3He fuelled/field reversed configuration (FRC) plasmas is investigated. Some of the tritons produced by D(d,p)T reactions in the FRC are immediately and asymmetrically lost from the device without any interaction with background charged particles, and then non-symmetric loss causes a distortion of the velocity distribution function as well as a decrease in the number of trapped tritons. Using the distorted triton distribution, the 14 MeV neutron generation rate is estimated and compared with the values for Maxwellian plasmas (the effect of the magnetic field is neglected). It is found that in a typical ignited D-3He/FRC plasma, for example, Ti = Te = 80 keV, nD = 2n3He = 0.5ne = 3 × 1020m-3, τE = 0.5τP = 3 s, rs = 1.6 m and BW = 6 T, the reduction in 14 MeV neutron generation is about 20%.

A variable-temperature scanning Hall probe microscope was developed for imaging a microscopic magnetic field distribution. The microscope probes the surface of magnetic materials with a micro-Hall probe, whose active area is 0.6-2.0 μm2. The microscope‘s operating temperature range is between room temperature and liquid He temperature. The results of observing magnetic images of a thermally demagnetized permanent Sr-ferrite magnet at room temperature and a high-temperature superconducting NdBa2Cu3Oy thin film at 77 K are presented.

To reduce the cost of amorphous silicon photovoltaic modules, a monolithic structure and an encapsulation process with liquid resin has been developed. The line speed of the encapsulation process can be up to 190 cm/min with a simple apparatus, which corresponds to 40 MW/y. The process was applied with actual amorphous silicon photovoltaic modules with a size of 910 × 455 mm2. The aperture efficiency of the photovoltaic module was 10.6% (41.9 W). The modules passed five acceleration tests stated in JIS C 8917, i.e., dump-heat test, salt-mist cyclic test and humidity-freeze test. Field tests which have been carried out in Japan and Arizona assured that the encapsulation with liquid resin is as reliable as the conventional encapsulation with EVA/Tedler. The cost of the liquid resin could be reduced to 80% of original one without reducing reliability, by investigating the recipe of an organic compound.

Hunter disease is an X-linked recessive mucopolysaccharide storage disorder caused by iduronate-2-sulfatase deficiency and is rare in females. We describe here findings in a girl with Hunter disease of the severe type. She had a normal karyotype but a marked deficiency of iduronate-2-sulfatase activity in lymphocytes and cultured fibroblasts. In a sequence analysis of the iduronate-2-sulfatase gene, evidence was obtained for the R468Q (G1403 to A) mutation, a common one in Hunter disease. RT-PCR showed her cDNA to represent only the R468Q allele, although at the genomic level she was a heterozygote with one normal allele. Her brother had the R468Q mutation, and their mother was a carrier of this mutation. The fusion products of CHO (TG(R),Neo(R)) with patient's fibroblasts cultured in HAT/G418 selective medium, carried only the maternal allele. However, in genomic DNA from the patient's fibroblasts, only the paternal allele of the androgen receptor gene, a gene subjected to differential methylation of the inactive X-chromosome, was methylated. These findings strongly suggest that the severe form of Hunter disease in this girl was the result of selective expression of the maternal allele carrying the missense mutation R468Q, which in turn resulted from skewed X inactivation of the paternal nonmutant X chromosome.

A gate driver IC with programmable output resistance (Rout) capable of performing current balancing for parallel connected IGBTs is presented in this paper. This novel method is to dynamically adjust the gate driver Rout to minimize the difference in the turn-on/off delay times between parallel connected IGBTs. The programmable gate driver Rout is implemented using a segmented output stage technique. This gate driver IC is designed and fabricated using TSMC's 0.18μm BCD Gen-2 process. Experimental results are obtained by measuring the current distribution between two parallel connected IGBTs (600V, 90A). These results indicate an improvement in average current imbalance of 89% and 98% for the turn-on and off periods, respectively.

In this paper, a segmented IGBT gate driver IC for mitigating IGBT turn-on IC over-shoot is presented. The proposed IC is fabricated using TSMC's 0.18 μm BCD Gen-2 process. Unlike existing IC over-shoot reduction techniques, the proposed technique does not require significant additional external components or an increase in turn-on energy. During turn-on, the gate driver is controlled such that (dVGE/dt) is kept low as current is transferred from the FWD to the IGBT and kept high at all other times. The ideal timing of (dVGE/dt) transitions could vary between IGBT devices, age, temperature, etc. A feedback system is used to correct for these variances. A 37% reduction in IC overshoot is achieved while maintaining the same EON. A 54% reduction in EON is achieved for the same IC overshoot. Finally, a 15.5 dBm reduction in CEMI is observed when compared to operation with a constant ROUT and similar Eon.

In high power applications, switching devices such as MOSFETs and IGBTs must often be connected in parallel in order to provide higher current capability. However, the current imbalance of parallel connected IGBTs due to stray inductance, variations in device characteristics and asymmetric PCB layout, necessitates de-rating of the IGBTs. This deliberate de-rating is required in order to ensure the IGBTs function within their Safe-Operating-Area. Unfortunately, de-rating also leads to an increase in cost, size and complexity of the overall power electronics system. A current balancing method for parallel connected IGBTs using a dynamically adjustable gate driving resistance (Rg_dyanmic) is presented in this paper. Experimental results are achieved by measuring the current distribution between two parallel connected IGBTs (rated at 600V, 90A). These experimental results indicate an improvement in average current imbalance of 74% and 65% for the turn on and off periods, respectively.

Samples of Ba- and Sr-hexaferrite were prepared by mechanical alloying and subsequent heat treatment were found to consist of single domain particles of the single hexaferrite phase. The particles had a wide distribution of anisotropy fields. Study of irreversible magnetisation suggested, that the demagnetisation process is mainly controlled by the Wohlfarth rotation. It was deduced from the results of measurements of magnetic viscosity, that the activation volume was of same order of magnitude as the cube of the domain wall thickness.

The clonal growth of progenitor cells from myelodysplastic syndromes (MDS) can be subdivided into four growth patterns: (1) normal, (2) no growth or low plating efficiency, (3) low colony and high cluster number, and (4) normal or high colony number with a large number of clusters. The former two (1 and 2) can be referred to as nonleukemic patterns and latter two (3 and 4) as leukemic. In a search for a role for cytokines in leukemic-type growth of MDS progenitor cells, marrow CD34+ cells were purified up to 94% for 8 normal individuals and 88% for 12 MDS patients, using monoclonal antibodies and immunomagnetic microspheres (MDS CD34+ cells). The purified CD34+ cells were cultured for 14 days with various combinations of cytokines, including recombinant human macrophage colony-stimulating factor (rM-CSF), granulocyte-CSF (rG-CSF), granulocyte-macrophage-CSF (rGM-CSF), interleukin-3 (rIL-3), and stem cell factor (SCF; a ligand for c-kit) in serum-free medium. The clonal growth of MDS CD34+ cells supported by a combination of all of the above cytokines was subdivided into the two patterns of leukemic or nonleukemic, and then the role of individual or combined cytokines in proliferation and differentiation of MDS CD34+ cells was analyzed in each group. Evidence we obtained showed that SCF plays a central role in the leukemic-type growth of MDS CD34+ cells and that G-CSF, GM-CSF; and/or IL-3 synergize with SCF to increase undifferentiated blast cell colonies and clusters over that seen in normal CD34+ cells. SCF is present in either normal or MDS plasma at a level of nanograms per milliliter, and this physiologic concentration of SCF can stimulate progenitor cells. This means that progenitor cells are continuously exposed to stimulation by SCF in vivo and that MDS leukemic cells have a growth advantage over normal blast cells. This depends, at least in part, on cytokines such as G-CSF, GM-CSF, IL-3, and SCF.

Melt-spun ribbons of Sm-Fe(-Co)-M-N(M=Zr,Nb,B,Si,Al,Ti) system alloys were prepared by the single roller rapid quenching method. The effect of composition, heat-treatment and nitrogenation were studied. A highest (BH) max =126.2 kJ/m 3 with B r =0.95T and H cj =740kA/m were obtained for (Sm 8 Zr 3 Fe 85 Co 4 ) 85 N 15 system isotropic powders. The X-ray diffraction analysis and transmission electron microscopy (TEM) observation showed this powder to consist of a nanoscale mixture with a SmFe7-N phase with the TbCu 7 -type structure and α-Fe in the size range of 20-50nm. Small deterioration of magnetic properties during pulverization and stable magnetic properties for long time aging at elevated temperature for these powders were observed.

the magnetic aftereffect constant (S v ), the anisotropy field (H A ) distribution and the rotational hysteresis integral (R h ) were measured for M-type hexagonal strontium ferrite (SrM) fine particles with various average particle diameters (D) and coercive forces (H cJ ). The relations between S v , the activation volume (v), H cJ , H A , and R h were studied, as well as the effect of milling. S v is constant and independent of the magnetic field. In S v varies in proportion to In H cJ , and the relation H cJ ?v?2 was found to obtain in SrM particles not extensively subjected to milling. S v increases and v decreases for SrM fine particles (D=0.3 ?m) whose H A is widely distributed by milling, even though H cJ decreases markedly. S v and v are related to the distribution of H A . As H cJ increases, R h and v decrease, which indicates that the magnetization reversal mechanism of SrM fine particles approaches that of a coherent rotation mode.

Submicron-size particles of M-type Sr ferrite were obtained from fine Fe 2 O 3 and precipitated SrCO 3 . The magnetic properties of the powder were ? s =71 emu/g and H cJ =5.5 kOe. The Hc J of the powder was reduced to less than 40% of its initial value by dry vibration milling. SEM observations showed that the primary particle size distribution was not much different from that in the initial state. Crystal distortion was determined by X-ray diffraction studies, using the method of Warren and Averbach. The torque curve of the milled powder was measured using a highly sensitive torque magnetometer. The dependence of K 2 /K 1 on the measuring magnetic field was increased with milling-induced crystal distortion. The Mossbauer absorption effect was also measured. submicron particles were analyzed in comparison with coarse Sr ferrite particles (3 ?m) by a conventional breaking-down process.

A gate driver IC with programmable driving strength to reduce conducted electromagnetic interference (CEMI) in SMPS is presented in this paper. The solution presented is to dynamically adjust the gate driving strength (output resistance R out ) at the arrival of each gate pulse to minimize CEMI while maintaining low switching loss. Dynamically adjusting R out is not possible with conventional gate driver designs. A segmented gate driver is designed and fabricated in the AMS 0.35μm 40V HVCMOS process. Unlike snubber circuits, the proposed method does not require extra discrete components or wasted energy. Experimental results indicate up to a 7dBμV improvement in peak CEMI between 20 MHz and 30 MHz.

A potent and selective P type calcium channel blocker isolated from the venom of the funnel web spider Agelenopsis aperta, omega-agatoxin IVA, and its related peptides were synthesized by the solution procedure. Synthetic omega-agatoxin IVA was found to block high-threshold P-type calcium current in rat Purkinje neuron with the same potency as that reported for the natural product. Its disulfide structure was determined by amino acid analysis, gas-phase sequencing and mass spectrometry of the proteolytic fragments. The N-terminus biotinylated and truncated peptides showed the same disulfide-bond-forming profile and the same activities as those of omega-agatoxin IVA, indicating that the N-terminal basic tripeptide, Lys-Lys-Lys, is not important for both the folding and the expression of the biological activity. However, the Trp residue in the molecule might be essential for the toxin to bind tightly with the channel pores.

We report here the second evidence of retrotransposition of L1, which was found inserted into the dystrophin gene of a patient, causing Duchenne muscular dystrophy (DMD). When the PCR was used to amplify a region of the dystrophin gene encompassing exon 44 from genomic DNA of two Japanese brothers with DMD, it was found to be approximately 600 bp larger than expected. Both the normal and the abnormally large products were amplified from the DNA of their mother. However, the maternal grandparents did not have the abnormal allele, and the mutation must therefore have occurred in the mother. Analysis of nucleotide sequence of the amplified product from a patient disclosed that the insertion was present zero to two bases upstream from the 3' end of exon 44 and that two to four bases of the exon sequence were deleted from the insertion site. The insertion sequence was found to be composed of 606-608 bp and to be almost identical to the inverse complement of 3' portion of the L1 retrotransposon consensus sequence. The dystrophin gene transcript from peripheral lymphocytes of one of the patients was analyzed by using reverse transcription/semi-nested PCR. The size of the amplified product encompassing exon 42 to 46 was smaller than expected. Sequencing of the amplified product disclosed that the sequence of exon 43 was directly joined to that of exon 45. Exon 44 of the transcript was thus shown to be skipped during splicing. This novel mutation of the dystrophin gene has important implications regarding retrotransposition of an active L1 element and provides a new insight into the origins of mutations in the dystrophin gene.

Compression bonded magnets were manufactured using melt-spun ribbons of Nd 11 Fe 72 Co 8 B 7.5 V 1.5 , MQP-B and MQP-D (GM Co., Ltd.). The magnetic field and temperature dependences of the magnetic aftereffect constant (S v ) which determines the magnetic stability were studied. Compared with bonded magnets based on MQ powders, Nd 11 Fe 72 Co 8 B 7.5 V 1.5 bonded magnets had a larger (BH) max but a smaller S v (2.3 kA/m). The temperature dependence of S v for Nd 11 Fe 72 Co 8 B 7.5 V 1.5 bonded magnets was better than that for Nd-Fe-B sintered magnets. The activation volumes (v) at room temperature of Nd-Fe-Co-B-V, MQP-B and MQP-D bonded magnets were approximately 18×10?25, 15×10?25 and 18×10?25 m3, respectively. The relation among H cJ , S v and v (the Barbier plot) was studied for these Nd-Fe-B system compression bonded magnets, as well as for Sm 2 Co 17 sintered magnets and Sm 2 Co 17 system compression bonded magnets, in which magnetization reversal is by the same pinning mechanism. From the results of Barbier plots it was found that the relation between In S v and In H cJ is linear, and that H cJ is proportional to v?0.6.

Magnetic dot-arrays with dot diameters of 80 to 1000 nm have been fabricated by patterning CoPt alloy continuous films. All of the fabricated dots had their magnetic easy axes perpendicular to the plane. From MFM observations, dots with diameters of 160 nm and larger had multi domain structures. For the dot-array with 80 nm dot diameter, every dot was observed as a single domain. CoPt dot-array with 80 nm dot diameter showed excellent thermal stability in comparison with conventional longitudinal media and perpendicular media.

The effect of lansoprazole, a proton pump inhibitor (PPI), on indomethacin-induced small intestinal ulceration was examined in rats, particularly in relation to heme oxygenase (HO)-1. The animals were administered indomethacin (10 mg/kg, p.o.) and killed 24 h later. Lansoprazole (30-100 mg/kg, p.o.) and omeprazole (30-100 mg/kg, p.o.) were given 30 min before the administration of indomethacin, while tin-protoporphyrin IX (SnPP: 30 mg/kg, i.v.), an inhibitor of HO-1, was injected 10 min before indomethacin or lansoprazole. Indomethacin produced hemorrhagic lesions in the small intestine, accompanied with an increase of mucosal invasion of enterobacteria, inducible nitric oxide synthase (iNOS) expression, and myeloperoxidase (MPO) activity in the mucosa. Pretreatment with lansoprazole dose- dependently reduced the severity of the indomethacin-induced intestinal lesions, with suppression of the increased MPO activity, while omeprazole had no effect. Pretreatment with SnPP significantly exacerbated these intestinal lesions and almost totally abolished the protective effect of lansoprazole. The up-regulation of iNOS mRNA expression following indomethacin was suppressed by lansoprazole in a SnPP-inhibitable manner, although the enhanced enterobacterial invasion remained unaffected. The amount of HO-1 protein in the intestinal mucosa was significantly increased by lansoprazole but not by omeprazole. Prior administration of carbon monoxide (CO)-releasing molecule-2 (CORM-2; 10 mg/kg, i.p.) significantly reduced the severity of these lesions and the enhancement of mucosal iNOS mRNA expression induced in the small intestine by indomethacin. These results suggest that lansoprazole prevents indomethacin-induced small intestinal ulceration, and this effect is associated with inhibition of iNOS expression, through up-regulation of HO-1/CO production in the mucosa.

Substance P (SP) binding protein of rat brain was solubilized by digitonin. The solubilized proteins were then purified by sequential gel filtration, concanavalin A lectin Sepharose, and SP-affinity chromatography. The calculated molecular weight of this purified SP binding protein was 76-74 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The rabbits were immunized with the purified protein and resulting polyclonal anti-sera were tested. The immune serum significantly inhibited [3H]SP binding to the 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate solubilized membrane fractions from rat brain, whereas pre-bleed antiserum failed to inhibit the binding. This polyclonal antibody also inhibited the activity of 45Ca influx into astroglioma cells stimulated by SP, but does not inhibit that stimulated by histamine. Furthermore, this polyclonal antibody recognized the 76-74 kDa band as assessed by Western blotting. These data strongly suggest that this polyclonal antibody could recognize a part of the natural SP receptor site.

In this paper, the transistor sizing of an auxiliary output stage in a digitally controlled transient suppression system for fully integrated point-of-load (POL) DC-DC converters is investigated. The auxiliary output stage is added in parallel to the main output switching stage to help reduce output voltage deviation during load transient. The sizing of the auxiliary output stage in relation to the main output stage is studied through analysis and simulation of a 3 W, 12 V to 1 V buck converter. The auxiliary output stage performs well with transistors occupying as little as 5% the area of the main output stage.

Fast load transient response and high power conversion efficiency in DC-DC converters have conflicting requirements on the size of the inductor. In this paper, an integrated point-of-load (POL) DC-DC converter with an smaller auxiliary output stage added in parallel to the main output switching stage to help reduce the output voltage deviation during load transient is investigated. The transistor sizing of the auxiliary output stage in relation to the main output stage is studied through analysis and simulation of a 12 V to 1 V, 3 W, buck converter. The auxiliary output stage performs well with transistors occupying as little as 5% the area of the main output stage.

It was described in a previous paper that fully dense TiB2-20 wt pct sintered bodies were fabricated by glass encapsulation HIP, and their three-point bending strength was as high as 1200 MPa. In this material, grain growth occurred during sintering; the grain sizes of TiB2 and ZrO2 in a sintered (HIP'd) body were 4-6 microns and 2-5 microns, respectively, while starting powder sizes of TiB2 and ZrO2 were 2 microns and 0.1 micron, respectively. To minimize this grain growth, 2.5-5 wt pct SiC, whose size was 0.2 micron, was added. As a result, the grain sizes of TiB2 and ZrO2 in a sintered body were 2-4 microns and 1-3 microns, respectively. The three-point bending strength has increased to 1280 MPa. In addition to improving strength, adding SiC improved the sinterability of TiB2-20 wt pct; the sintered body whose density was 98.0 percent of full density was fabricated by vacuum sintering.

We examined the effects of various NO inhibitors on the healing of DSS-induced rat colitis. Experimental colitis was induced by feeding rats for 6 days with 2.5% DSS in drinking water. After DSS treatment, the animals were fed normally and killed various days up to 7 days later. L-NAME (a nonselective NOS inhibitor) or aminoguanidine (a selective iNOS inhibitor) was given p.o. twice daily for 6 days starting from the termination of DSS treatment. The area of lesions, colon length and MPO activity were measured on day 7 after DSS treatment. DSS treatment caused severe lesions in the colon, accompanied by an increase in MPO activity and a decrease in colon length. The lesions healed gradually after discontinuation of DSS treatment, with a histological restoration and subsidence of inflammation. The healing of DSS-induced colonic lesions was significantly impaired by daily administration of L-NAME or aminoguanidine, the effects being all but equivalent between these drugs, and the effect of L-NAME was significantly reverted by the co-administration of L-arginine. The expression of nNOS protein was observed in the colonic mucosa with or without DSS treatment, while those of iNOS and eNOS were markedly upregulated after DSS treatment. Likewise, the expression of VEGF was also up-regulated in the colon following DSS treatment, and this response was suppressed by both L-NAME and aminoguanidine. These results suggest that endogenous NO produced by mainly iNOS and partly eNOS contributes to the healing of DSS-induced colonic lesions, through the upregulation of VEGF expression and enhancement of angiogenesis.