Evaluation of counterions for electrospray ionization mass spectral analysis of a highly sulfated carbohydrate,sucrose octasulfate

A systematic approach was used to evaluate the electrospray ionization mass spectral (ESI-MS) analysis of sucrose octasulfate (SOS), an important pharmaceutical agent. SOS represents a model for other suffated carbohydrates, such as heparin and glycosaminoglycan-derived oligosaccharides that also are highly sulfated and pose difficult analytical problems. A survey of ammonium counterions showed that 1 degree, 2 degrees, and 3 degrees ammonium salts of SOS gave substantial fragmentation as a result of sulfate loss. In contrast, quaternary ammonium and phosphonium salts gave excellent ESI spectra, particularly in the positive ion mode. This represents the first report of the ESI-MS analysis of sulfated carbohydrates in the positive ion mode.     

Hydrogen isotope permeation from cooling water through various metal piping

In order to investigate the behavior of hydrogen isotope on the water–metal boundary, deuterium permeation experiments from heavy water vessel through various metal piping, such as pure iron (Fe), nickel (Ni), stainless steel (SS304), and pure iron with 10 μm gold plating, were performed at 573 K and at 15 MPa. During the experiment, surfaces of metal piping except gold plating one were oxidized at the heavy water boundary and then deuterium would generate by the oxidation reactions. This deuterium could be detected by mass spectrometer, which monitored the inside gases of the piping under continuous evacuation. The result showed clearly that the deuterium permeated through Fe, Ni, and SS304 piping was detected as mainly deuterium gas (D₂) under continuous evacuation, though that through gold plating one could not be detected effectively. The D₂ permeation rate through Fe, Ni, and SS304 piping reached equilibrium conditions with oxide generation at D₂O–metal boundary, although concluding the transfer mechanism will require further testing and modeling activities.     

Inkjet‐Printed Lithium–Sulfur Microcathodes for All‐Printed,Integrated Nanomanufacturing

Improved thin‐film microbatteries are needed to provide appropriate energy‐storage options to power the multitude of devices that will bring the proposed “Internet of Things” network to fruition (e.g., active radio‐frequency identification tags and microcontrollers for wearable and implantable devices). Although impressive efforts have been made to improve the energy density of 3D microbatteries, they have all used low energy‐density lithium‐ion chemistries, which present a fundamental barrier to miniaturization. In addition, they require complicated microfabrication processes that hinder cost‐competitiveness. Here, inkjet‐printed lithium–sulfur (Li–S) cathodes for integrated nanomanufacturing are reported. Single‐wall carbon nanotubes infused with electronically conductive straight‐chain sulfur (S@SWNT) are adopted as an integrated current‐collector/active‐material composite, and inkjet printing as a top‐down approach to achieve thin‐film shape control over printed electrode dimensions is used. The novel Li–S cathodes may be directly printed on traditional microelectronic semicoductor substrates (e.g., SiO₂) or on flexible aluminum foil. Profilometry indicates that these microelectrodes are less than 10 µm thick, while cyclic voltammetry analyses show that the S@SWNT possesses pseudocapacitive characteristics and corroborates a previous study suggesting the S@SWNT discharge via a purely solid‐state mechanism. The printed electrodes produce ≈800 mAh g^?1 S initially and ≈700 mAh g^?1 after 100 charge/discharge cycles at C/2 rate.     

Integrated circuits for television receivers

Integrated circuits are being investigated for use in as many television circuits as feasible. In Japan, considerable work has been done by different groups within the TV industry to develop ICs that will permit cost reduction, increased reliability, and simplification of assembly-line operations. This article is a report on results of the concentrated efforts made by five major television set manufacturers to develop and produce black-and-white and color receivers, in collaboration with four universities, two institutes, and seven components manufacturers.     

Simulation of transverse crack formation on continuously cast peritectic medium carbon steel slabs

Reliable data are limited to the critical strain for the formation of transverse cracks on the slabs, owing to experimental difficulty to simulate temperature gradient in solidified shell in continuous casting mold. The present study is to determine the critical strain, ?_c, for the formation of transverse cracks on continuously cast slabs. A convenient and simple hot tensile test using rectangular test pieces with either V-notch or semi-circle notch or oscillation marks has been developed by placing the specimen under similar temperature gradient to that in solidified shell in the mold. The ?_c has been determined at a better accuracy and reproducibility, and the ?_c at a strain rate of 5?10^?4s^?1 is found to be a high 35% for test pieces without notch. It sharply decreases, however, to 10% for those with V- and semi-circle-notches, slightly decreases with increasing notch depth, and further decreases for those with oscillation marks that accompany solute segregation. Reduction of the oscillation mark depth is shown to be important measure to prevent the occurrence of transverse cracking of continuously cast slabs.     

Observation of metal on Si(0 0 1) by STM/STS and its consideration based on the first principles calculations

Local density of states (LDOS) is obtained by the first principles calculation based on the density functional theory on the Si(0 0 1)2 × 1 surface and on the surface with an Al dimer. At an Al dimer, LDOS has a high intensity in the conduction band region, which cannot be seen on the Si(0 0 1)2 × 1 surface. This tendency is observed in STS measurements as well. The possibility for a microelementary analysis is presented by applying this method to other metal atoms on the Si surface. Furthermore, it is pointed out that STS measurements should be always performed at the same tip-sample separation to obtain reproducible STS spectrums.     

Sequence analysis of SRSV in fecal specimens from an epidemic of infantile gastroenteritis, October to December 1995, Japan

BACKGROUND AND HYPOTHESIS: Valvar pulmonary stenosis is a common congenital heart defect. Progression of stenosis over time, even when mild initially, has been shown by serial cardiac catheterization studies in children and adults. We studied the natural history of asymptomatic valvar pulmonary stenosis diagnosed in infancy with two-dimensional echocardiography and Doppler method. METHODS: Between November 1986 and March 1993, 51 infants in the Northeast Tennessee and Southwest Virginia region were clinically diagnosed to have isolated valvar pulmonary stenosis. In 40 patients, the diagnosis was confirmed by two-dimensional echocardiogram/Doppler and color-flow mapping study at the time of presentation, and only their course is reported. Of 40 infants, six asymptomatic infants (15%) showed rapid progression of pulmonary stenosis over a relatively short period of time. Within the first 6 months of life, three of the six infants showed worsening of the stenosis needing intervention (one had surgical valvectomy and the others had percutaneous balloon valvuloplasty). The three other infants showed a more gradual increase of pulmonary stenosis over the first 2 years of life. RESULTS: Pulmonary stenosis even when mild can worsen in infancy, and it is not possible to predict which patients will follow this course. In our group of asymptomatic infants with initial mild pulmonary stenosis, 15% developed significant stenosis that needed intervention. CONCLUSION: We recommend frequent follow-up of asymptomatic infants with mild pulmonary stenosis during the first 2 years of life to detect rapid progression that may need intervention.     

220,000‐r/min, 2‐kW PM motor drive for turbocharger

This paper describes an ultrahigh‐speed permanent‐magnet synchronous motor drive, which is embedded in a turbocharger of an internal‐combustion engine. The electrical drive makes it possible to enhance output power of the turbocharger in a motoring mode and to retrieve combustion energy from exhaust gas in a regenerating mode. Computer simulations and experimental tests are conducted to examine various operation characteristics of a prototype. The experimental data demonstrate 220,000‐r/min operation at 2.2‐kW inverter output power, in good agreement with the simulation results and proving the feasibility of the proposed system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(3): 31–40, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20408     

Short‐current pulse‐based adaptive maximum‐power‐point tracking for a photovoltaic power generation system

This paper focuses on a maximum‐power‐point tracking method of photovoltaics via use of the short‐current pulse. It has been reported that the optimum operating current is proportional to the short current and that maximum‐power‐point tracking can be performed by detecting the short current. The proposed method utilizes the intermittent short‐current pulse to estimate the optimum operating current and its operating characteristics have experimentally been verified. Also, an adaptive mechanism to identify the parameter between the optimum current and the short current is discussed. A prototype of the controller has been set up and the experimental results have demonstrated excellent performance, proving the feasibility of the system. © 2002 Scripta Technica, Electr Eng Jpn, 139(1): 65–72, 2002; DOI 10.1002/eej.1147     

Determinants of collateral development in a canine model with repeated coronary occlusion

It is now accepted that repetitive 2-min coronary occlusion can develop collateral vessels to the area perfused by the occluded coronary artery. However, which factors influence collateral development has yet to be fully elucidated. The goal of the present study was to identify the determinants of the rate of coronary collateral development in dogs undergoing repeated coronary occlusion. The study was conducted in 19 conscious dogs instrumented for measurements of a subendocardial segment length in the area perfused by the left circumflex coronary artery (LCCA), LCCA flow, and left ventricular pressure. An externally inflatable pneumatic occluder was placed around the LCCA. After the recovery from surgery, 2-min LCCA occlusions were conducted eight times daily. Following 141 +/- 61 (SD) LCCA occlusions (20 +/- 7 days), an LCCA occlusion produced no reduction in segment shortening and negligible reactive hyperemia. The total number of LCCA occlusions needed for adequate collateral development (the rate of collateralization) correlated well with the severity of myocardial ischemia during the first occlusion, which was determined mainly by the extent of postsurgical initial collateral circulation. On the other hand, the response to the ischemic stimulus in the later stage of collateral development was independent of the extent of development of the initial postsurgical collaterals. It is concluded that the overall rate of collateral development is slower in dogs with initially poorer collaterals; however, the response of each dog to the ischemic stimulus in the later stage of collateral development was similar among dogs regardless of the extent of the initial collaterals.