X-ray diffraction measurements in high magnetic fields and at high temperatures

A system was developed measuring x-ray powder diffraction in high magnetic fields up to 5 T and at temperatures from 283 to 473 K. The stability of the temperature is within 1 K over 6 h. In order to examine the ability of the system, the high-field x-ray diffraction measurements were carried out for Si and a Ni-based ferromagnetic shape-memory alloy. The results show that the x-ray powder diffraction measurements in high magnetic fields and at high temperatures are useful for materials research.     

A life-cycle analysis on thin-film CdS/CdTe PV modules

Authors have evaluated the life cycle of a thin-film CdS/CdTe PV module to estimate the energy payback time (EPT) and the life-cycle CO₂ emissions of a residential rooftop PV system using the CdS/CdTe PV modules. The primary energy requirement for producing 1 m² of the CdS/CdTe PV module was similar to a-Si PV module at annual production scale of 100 MW. EPT was calculated at 1.7–1.1 yr, which was much shorter than the lifetime of the PV system and similar to that of a-Si PV modules. The life-cycle CO₂ emissions were also estimated at 14–9 g-C/kWh, which was less than that of electricity generated by utility companies.     

Pathophysiology of Preeclampsia: The Role of Exosomes

The pathogenesis of preeclampsia begins when a fertilized egg infiltrates the decidua, resulting in implantation failure (e.g., due to extravillous trophoblast infiltration disturbance and abnormal spiral artery remodeling). Thereafter, large amounts of serum factors (e.g., soluble fms-like tyrosine kinase 1 and soluble endoglin) are released into the blood from the hypoplastic placenta, and preeclampsia characterized by multiorgan disorder caused by vascular disorders develops. Successful implantation and placentation require immune tolerance to the fertilized egg as a semi-allograft and the stimulation of extravillous trophoblast infiltration. Recently, exosomes with diameters of 50–100 nm have been recognized to be involved in cell–cell communication. Exosomes affect cell functions in autocrine and paracrine manners via their encapsulating microRNA/DNA and membrane-bound proteins. The microRNA profiles of blood exosomes have been demonstrated to be useful for the evaluation of preeclampsia pathophysiology and prediction of the disease. In addition, exosomes derived from mesenchymal stem cells have been found to have cancer-suppressing effects. These exosomes may repair the pathophysiology of preeclampsia through the suppression of extravillous trophoblast apoptosis and promotion of these cells’ invasive ability. Exosomes secreted by various cells have received much recent attention and may be involved in the maintenance of pregnancy and pathogenesis of preeclampsia.     

Three-dimensional organization of the golgi complex observed by scanning electron microscopy

With the development of new specimen preparation techniques and improvements in instrumental resolution, scanning electron microscopy (SEM) became an effective means of studying the three-dimensional organization of the Golgi complex. When specimens prepared by the osmium-DMSO-osmium method are observed with high-resolution SEMs, cis-most cisternae of Golgi stacks appear as sieve-like plates with many small perforations. In some cell types, larger fenestrations are also present. The trans-most cisternae showed a fenestrated or retucular pattern. At the trans-side of Golgi stacks, distinctive structures, such as a well-developed tubular plexus or a single widely extended cisterna, are observed in some types of cells. In lacrimal gland cells, Golgi stacks are linked by an irregular network of anastomosing branches extending throughout the cytoplasm. In these cells, the piled cisternae seemed to be connected to each other either directly within the stack or via cisternae of other stacks. Connections between Golgi stack and rough endoplasmic reticulum (ER) were often found in our SEM observations. In nerve cells, interconnecting tubules arise from rough ER and most often fuse with the rim of the cis-cisternae of Golgi stacks.     

Effects of iodine intercalation into Bi-based copper oxide superconductors

We have investigated the stage-1 iodine-intercalation compounds, whose host materials are Bi₂Sr₂Ca_1–x Y _x Cu₂O₈ (Bi-2212 phase) and Bi_1.6Pb_0.5Sr_1.9–x La _x Cu_1.05O₆ (Bi-2201 phase) with variousx values. In the Bi-2212 phase, it has been found that the change inT _c through the stage-1 iodine intercalation is due to two effects; a change of the two-dimensionality and an increase in the carrier number. The former effect decreasesT _c by about 10 K independent of the carrier number of the host sample. The latter effect shifts thex dependence ofT _c to largerx values by about 0.08, taking account of oxygen release from the host samples during the intercalation process. This result is clear evidence for the occurrence of both the change of two-dimensionality and the increase in carrier number about 0.04 per CuO₂ unit due to the charge transfer through the stage-1 iodine intercalation. In the Bi-2201 phase,T _c decreases by about 10 K through the stage-1 iodine intercalation.     

Oviposition Stimulants for Sulfur ButterflyColias erate poliographys: Cyanoglucosides as Synergistis Involved in Host Preference

Host-plant chemicals stimulating oviposition by a Leguminosae-feeding pierid butterflyColias erate poliographyswere isolated and identified from one of its primary host plants, white clover (Trifolium repens). Females readily deposited eggs in response to methanolic extracts of the plant, and subsequent partition of the extracts with organic solvents revealed that chemical constituents critical for host recognition reside in the water-soluble fraction. Further fractionation of the hydrosoluble fraction by column chromatography led to the separation of an active fraction and two cyanoglucosides, linamarin and lotaustralin. Conspicuous oviposition response was evoked by unidentified polar compound(s), while these cyanoglucosides exerted no stimulatory activity by themselves. However, ovipositing females preferred samples containing either of the two cyanoglucosides. In dual-choice bioassays, significantly more eggs were laid on samples admixed with the cyanoglucosides, suggesting that the cyanoglucosides serve as synergistic oviposition stimulants and could play an important role in host selection.     

Conducting Langmuir-Blodgett films as electrode materials

Photoelectric cells based on Langmuir-Blodgett (LB) films were fabricated using dye monolayers as photoconductors and N-docosylpyridinium-di(tetracyanoquinodimethane) (PT) monolayers as one of the electrode materials. It is found that PT films can be used as a wiring material instead of large work function metals such as silver or Ni-Cr. However, in comparison with the photoelectric cells using the conventional metals, a few different properties were observed for those wired with PT. These differences are assignable to the difference between the LB film-metal and the LB film-LB film contacts.     

Recognition of handprinted Hebrew characters using features selected in the Hough transform space

Automatic identification of handprinted Hebrew characters is described in this paper. The recognition model devised constitutes a multi-stage system. In the first stage a coarse classifier allocates the input patterns into one of 17 categories, based on the number and the location of end points within predetermined regions in the characters matrix. The second stage uses features extracted in the Hough transform space to classify characters assigned to each of 16 categories. The remaining one category, composed of similar, square-like (rotated L shape) classes, is recognized by structural analysis and a statistical classifier. An additional step of postprocessing is added to compensate for the sensitivity of the Hough transform to the existence of similar classes within some of the categories. Experiments were conducted with a multi-author (40 writers) data base. An average recognition rate of 86.9% was observed for the system. This compared favorably with the results of two other recognition methods.     

PWM Inverter Using High-Gain Pulse-Triggered Power Transistors and a New PWM Control Method

Rugged PWM transistor inverters are expected to be put into practical use for providing high reliability under adverse operating conditions. The bipolar power transistors are more common compared with MOSFET's power transistors in balance between power-handling capability and switching speed. High over current capability, low switching loss, high-speed switching, and high-current gain are requisite functions in the PWM inverter employing bipolar power transistors. These functions are of great concern in the power electronics field. A new PWM transistor inverter which can meet these requirements is presented in this paper. For this purpose, a concept of high-gain pulse-triggered power transistor (PTPT) with amorphous saturable current transformer (CT) is introduced.