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The action of methyl 3-phenyl-2 (E)-propenyl 1,4-dihydro-2,6-dimethyl- 4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (pranidipine, OPC-13340, CAS 99522-79-9) on the endothelium-dependent relaxation in the isolated aorta in vitro was examined in comparison with other calcium antagonists (nifedipine, nitrendipine, nicardipine, diltiazem and verapamil). In the isolated aortic preparation of Wistar rats, acetylcholine (10(-5) mol/l), ATP (10(-5) mol/l or histamine (10(-5)-10(-4) mol/l) caused endothelium-dependent relaxation when the strips were previously contracted with prostaglandin F2 alpha. This endothelium-dependent relaxation recovered within a few minutes, although the mechanisms of this contraction after relaxation were not clear. The pretreatment with pranidipine for 20 min extended the duration of the endothelium-dependent relaxation, however, there was no potentiation in magnitude of the relaxation. This effect on the duration of endothelium-dependent relaxation was prominent in pranidipine, namely, other calcium antagonists tested had not this action at clinical concentrations. This phenomenon was also observed when the strips were pre-contracted with norepinephrine. This action of pranidipine might be some beneficial feature for therapeutic use of the compound.

The effects of a new acetylcholinesterase inhibitor, ENA-713, on ischemia-induced changes in acetylcholine, monoamines, and their metabolites, were studied in the gerbil. ENA-713 (0.2 mg/kg) or saline was administered intraperitoneally to gerbils 30 min before induction of cerebral ischemia by bilateral carotid occlusion. Pretreatment with ENA-713 mitigated the ischemia-induced abnormalities of the cholinergic, dopaminergic and serotoninergic systems in the gerbil brain, although it had virtually no effect on acetylcholine, monoamines, or their metabolites in any region of the normal gerbil brain. These findings suggest that ENA-713 has beneficial effects against ischemia-induced cerebral disorders. Thus, ENA-713 seems to be promising as a preventive or therapeutic agent for cerebrovascular dementia due to cerebral ischemia and might be useful for the treatment of Alzheimer-type dementia which is associated with multiple neurotransmitter abnormalities in the brain.

The cardiovascular effects of OPC-13340, a newly developed 1,4-dihydropyridine calcium channel blocker, were examined in several canine preparations. In conscious normotensive and DOCA-salt hypertensive dogs, OPC-13340, at doses of 10 to 30 micrograms/kg, i.v., and 0.3 to 3 mg/kg, p.o., exerted an hypotensive action in a dose-dependent manner. The hypotensive action of OPC-13340 was longer lasting and more potent than that of nicardipine and nifedipine. In conscious, normotensive instrumented dogs, OPC-13340, at doses of 1 and 3 mg/kg, p.o., dose-dependently decreased total peripheral resistance and mean blood pressure and increased heart rate, cardiac output and left ventricular contractility. In anesthetized open-chest dogs, OPC-13340, at doses of 1 to 30 micrograms/kg, i.v., increased coronary blood flow and decreased mean blood pressure, heart rate, coronary vascular resistance, arteriovenous oxygen difference and myocardial oxygen consumption. In contrast to OPC-13340, nicardipine did not change the myocardial oxygen consumption. From these results it was concluded that OPC-13340 lowered blood pressure and improved coronary circulation in dogs and that the duration of these actions was longer lasting than that of nifedipine and nicardipine. These actions of OPC-13340 may be useful in the treatment of hypertension and angina pectoris.

Cefprozil (CFPZ, BMY-28100) is a new oral cephem antibiotic without an ester linkage. Pharmacokinetic and clinical studies using CFPZ 10% fine granules were performed in pediatric patients. 1. Pharmacokinetic investigation Peak serum concentrations of CFPZ after dose of 7.5 mg/kg and 10 mg/kg were, respectively, 3.65 +/- 0.24 micrograms/ml and 6.38 +/- 3.23 micrograms/ml at 1-2 hours. The average half-life with 7.5 mg/kg administration was 0.90 +/- 0.16 hours and that with 10 mg/kg was 1.29 +/- 0.50 hours. The urinary excretion of CFPZ was about 45% (35.3-50.0%) in 6 hours. 2. Clinical investigation Enrolled in the study were 22 patients including 4 with pharyngitis, 3 with tonsillitis, 3 with bronchitis, 5 with pneumonia, 4 with urinary tract infection, and 1 each with pertussis, purulent lymphadenitis and otitis media. Responses were excellent in 14 patients, good in 5 patients and fair in 1 patient. In the assessment of the bacteriological efficacy, 8 out of 17 strains of organism identified previous to the treatment were eradicated, 5 strains were found replaced by other bacteria and 4 strains persisted, hence the eradication rate was 76.5%. 3. No adverse reactions attributable to the drug were observed. From the above results, it has been concluded that CFPZ is a highly effective and safe agent for moderate respiratory and urinary tract infections in children.

e15110 Background: The alteration of serum-iron level during chemotherapy is already reported (Follezou, NEOPLASMA 1985). However, the correlation to prognosis has not been evaluated. The aim of this study was to evaluate the correlation between prognosis and serum-iron level in advanced / metastatic colorectal cancer (aCRC / mCRC) patients treated by FOLFOX / FOLFIRI. Methods: Serum-iron levels, hemoglobin, AST and ALT serum levels in immediately pre and post chemotherapy were analyzed in 58 aCRC / mCRC patients received FOLFOX-4 / FOLFIRI therapy between April 2005 and September 2008. 26 patients received FOLFOX-4 / FOLFIRI therapy as the final chemotherapy died by the time of analysis. These patients were categorized into the high increase group and the low increase group using 200% increase as cut-off value and the prognosis was compared. Results: Mean serum-iron levels in immediately pre and post chemotherapy were 71.7±29.0μg/dl and 186.8±83.2μg/dl, respectively, and significant increase after chemotherapy was observed (p No significant financial relationships to disclose.

Laboratory and clinical studies on cefpirome (CPR, HR 810), a newly developed cephem antibiotic, were performed. The results obtained are summarized as follows: 1. Absorption and elimination of the drug were examined in a total of 7 children including 3 cases of administered with 20 mg/kg intravenous bolus injection (i.v.), 2 cases with 20 mg/kg drip infusion (d.i.v.) for 60 minutes and 2 cases with 40 mg/kg (d.i.v.) for 60 minutes. Maximum serum levels were attained immediately after i.v. or d.i.v. Cmax's were 233 +/- 7.6, 88.5 +/- 14.5, and 116 +/- 15 micrograms/ml, respectively for the above 3 modes of administration. These values were determined using a bioassay method with Bacillus subtilis ATCC 6633. T 1/2 (beta)'s were 1.18 +/- 0.17, 1.61 +/- 0.28 and 2.68 +/- 0.83 hours, respectively. Cumulative urinary recovery rates were 40.2-69.8% in a period of 0-6 hours after admissions. 2. Clinical efficacies were evaluated in a total of 20 patients with ages ranging from 9 months to 11 years. The treated cases were 6 cases of acute pneumonia, 4 cases of acute bronchitis, 4 cases of acute purulent tonsillitis, 2 cases of acute urinary tract infections, 2 cases of cellulitis, 1 case of purulent lympadenitis and 1 case of acute otitis media. The clinical efficacy rate was 94.7%. Adverse reactions occurred in no patients. Abnormal changes in laboratory test values involved only 1 case with elevated GOT and GPT. CPR was considered to be a safe and useful drug in treating various infectious diseases in children.

Aqueous HF etching of the silicon surface removes surface oxide, leaving a silicon surface terminated inhomogeneously by silicon mono-, di-, and trihydrides. We studied the effect of the immersion in water following the HF etching, on the surface hydride structure on Si(111), by measuring Si-H stretching vibration using infrared absorption spectroscopy. Immersion in boiling water (100°C) for 600 s produces a surface homogeneously terminated with silicon monohydride normal to the surface and free of oxidation. We concluded that water can remove silicon dihydride and trihydride and leave a silicon surface terminated with monohydride. The homogeneous surface has a low defect density of less than 0.5%.

This paper has made an overview on elastic and structural aspects of three distinct superlattices under hydrostatic pressure up to about 8GPa, which were studied by our unique x-ray diffraction technique incorporated with a diamond-anvil cell. They are metallic fcc/fcc Au/Ni, bcc/fcc Mo/Ni, and semiconductive epitaxially-grown PbSe/SnSe superlattices. In their layer-stacking direction, both metallic superlattices show the supermodulus behavior while the semiconductive one doesn't. However, its pressure-driven cubic-to-orthorhombic phase transition, successively taking place in the SnSe and PbSe layers, has been found to significantly shift by stress due to its epitaxial growth.

24.4 W of laser output has been obtained by sun-pumped, Cr-codoped Nd:yttrium aluminum garnet ceramic. The water-cooled laser rod was pumped with a Fresnel lens focusing the natural sunlight. By using the advantages of the Fresnel lenses, the maximum output for unit area of sunlight was 18.7 W/m2. Direct concentrated solar illumination was used to pump a 9mm-diameter, 100mm length rod of Cr:Nd:YAG, which was obtained 9%-14% slope efficiency for the laser output. We have analyzed the Cr:YAG laser medium and found it to be an excellent high-power laser candidate for direct solar-pumping schemes which enhances the laser output about 1.8 times more than Nd:YAG.

Cryopreservation of cloned embryos is expected to be beneficial in improving the efficiency of somatic cell cloning in pigs. We have already demonstrated that normal piglets can be produced from in vitro-matured and fertilized (IVM/IVF) embryos vitrified at an early cleavage stage after delipation (Nagashima et al. 2007 Biol. Reprod. 76, 900–905). In this study we utilized this technique in an attempt to produce piglets from cloned embryos reconstructed with IVM oocytes. Nuclear transfer (NT) embryos were reconstructed using oocytes matured in vitro in NCSU23 and preadipocytes as nuclear donors. The embryos were cultured in PZM-5 for approximately 98 h, and those that had developed to the morula stage were delipated using a noninvasive method described previously (Esaki et al. 2004 Biol. Reprod. 71, 432–437). The embryos were treated with 4% trypsin at 38�C for 1 to 4 min to induce a slight swelling of the zona pellucida, and then centrifuged (12 000g, 38�C, 23 min) with 7.5 µg mL–1 cytochalasin B to polarize cytoplasmic lipid droplets within the perivitelline space. The embryos were cultured for 1 h and vitrified by the minimum volume cooling (MVC) method using a MVC plate (Cryotop�; Kitasato Supply Co., Tokyo, Japan) in the presence of 15% ethylene glycol, 15% DMSO, and 0.5 m sucrose as cryoprotectants. Vitrified embryos were rewarmed by immersing the MVC plate diretly into rewarming solution containing 1 m sucrose and 20% calf serum at 38�C for 1 min, followed by stepwise dilution of the cryoprotectants. The rewarmed embryos were cultured for 2 days to the blastocyst stage, and then treated with 0.5% pronase to remove the zona pellucida before transfer to the uterine horn of recipients. A total of 103 vitrified blastocysts were transferred to 2 recipient gilts. Both gilts became pregnant and farrowed 2 and 4 piglets, respectively (6/103, 5.8%). These results demonstrate that cloned piglets can be produced from NT embryos that have been cryopreserved at the morula stage using noninvasive delipation and vitrification procedures. This study was supported by PROBRAIN.

Transgenic (Tg)-cloned pigs expressing fluorescent proteins are very useful in research such as cell or tissue transplantation studies. In this study, we produced Tg-cloned pigs with an orange fluorescent protein, humanized Kusabira-Orange (huKO), and analyzed the characteristics of these pigs. Fetal fibroblast cells transduced with huKO gene by a gene silencing-resistant retroviral vector, pDΔNhuKO (Suzuki et al. 2002 J. Neurochem. 82, 953–960) were used as nuclear donors. Recipient cytoplasts were prepared using oocytes matured in vitro in NCSU23. The nuclear transfer (NT) embryos were transferred into oviducts of estrus-synchronized recipient gilts after culture in PZM-5 for 1 or 2 days. Cloned pigs obtained were analyzed by Southern blotting for the transgene integration. A total of 23 organs and tissues, including brain, eye, internal and reproductive organs, skin, skeletal muscle, and cartilage were examined by fluorescence stereomicroscopy. Cryo- and paraffin-embedded tissue sections were also prepared to examine fluorescence expression. Immunofluorescent staining of brain cryosection and flow cytometry analysis of peripheral blood cells were performed to identify huKO-expressing cells. Transfer of 429 NT embryos into 4 recipients resulted in 18 (4.2%) cloned offspring. Southern blotting analysis of the cloned pigs confirmed transduction of 2 to 17 copies of the huKO gene in each pig. Autopsy was performed in 6 pigs, and orange fluorescence was confirmed in all the tissues and organs examined in each pig. In addition, prominent orange fluorescence was detected in pancreatic islets and renal glomeruli, indicating that these transgenic pigs are ideal for islet cell transplantation studies. Expression of huKO was also detected in neurons, microglia, and astrocytes in the brain, and granulocytes, monocytes, macrophages, lymphocytes, and platelets in the peripheral blood cells, whereas the expression level in red blood cells was lower. Re-cloning was performed using primary culture fibroblast cells established from 2 Tg-cloned pigs. Transfer of 300 re-cloned embryos into 4 recipients resulted in 3 pregnancies. A re-cloned fetus at Day 44 of gestation showed systemic fluorescence. These results demonstrate that the retroviral vector pD?NhuKO is resistant to gene silencing in pigs, that transduction and expression of the huKO gene had no lethal effects on fetal development, and that a Tg-cloned pig expressing orange fluorescence can be produced by NT of fetal fibroblast cells transduced with the huKO gene. This study was supported by PROBRAIN.

Cryopreservation of mammalian metaphase-II (M-II) oocytes is still impractical compared to that of early stage embryos. In this study we examined the effects of delipation and mitotic spindle stabilization in order to improve the post-vitrification survival rate of in vitro-matured (IVM) porcine oocytes at the M-II stage. Cumulus–oocyte complexes that had been collected from slaughterhouse ovaries were matured in vitro in NCSU23 supplemented with 0.6 mm cysteine, 10 ng mL–1 epidermal growth factor (EGF), 10% porcine follcular fluid (PFF), and 10 IU mL–1 eCG and hCG. The denuded M-II oocytes were vitrified in the presence of 30% ethylene glycol and 0.5 m sucrose using the minimum volume cooling (MVC) method with a MVC plate (Cryotop�; Kitazato Supply, Tokyo, Japan). Vitrified embryos were rewarmed by immersing the MVC plate directly into rewarming solution containing 1 m sucrose and 20% calf serum at 39�C for 1 min, followed by stepwise dilution of the cryoprotectants. We compared the effects of previtrification treatments, namely, (1) delipation, (2) mitotic spindle stabilization, (3) delipation + mitotic spindle stabilization, and (4) no treatment. For delipation, we used a noninvasive method (Esaki et al. 2004 Biol. Reprod. 71, 432–437) that we had published previously with slight modification. The embryos were treated with 4% trypsin at 38�C for approximately two min to expand the zona pellucida, and then centrifuged (12 000g, 38�C 23 min) with 7.5 µg mL–1 cytochalasin B to polarize cytoplasmic lipid droplets within the perivitelline space. For mitotic spindle stabilization, M-II oocytes were vitrified in the presence of 1 µm paclitaxel. After the oocytes were rewarmed, electrical activation of the oocytes (150 V mm–1, 100 µs, one time) was carried out to induce parthenogenesis. These parthenogenetic embryos were cultured in PZM-5 for 7 days, and the number of vitrified embryos that developed into blastocysts with respect to each treatment was determined. The blastcyst formation rate and mean cell numbers of the blastcysts were compared among the treatment groups (chi-square test, Tukey's test). Of the 50 M-II oocytes that had been vitrified without pretreatment, only one oocyte (2.0%) developed into a blastocyst with 20 cells. By contrast, the number of vitrified embryos that developed into blastocysts was significantly high when they were delipated prior to vitrification (37.8%, 14/37, 64.0 � 9.6; P < 0.01). Mitotic spindle stabilization also improved the survival rate of vitrified oocytes (18.6%, 21/113, 56.7 � 9.6; P < 0.01). The combination of delipation and mitotic spindle stabilization produced the highest number of vitrified oocytes that developed into blastocysts (43.8%, 35/80, 69.4 � 6.4), although the difference between the combination group and the delipation group was not significant. These results indicate that blastocysts can be produced very efficiently from IVM porcine oocytes that have been vitrified at the M-II stage using both noninvasive delipation and mitotic spindle stabilization procedures.

A hospital-based case-control study was conducted at 8 hospitals in Osaka in order to clarify risk factors among non-smoking women. A total of 129 lung cancer cases and 519 controls were investigated. An elevated risk was observed for women who had used wood or straw as cooking fuels at 30 years of age. Maternal smoking in childhood also seemed to raise the risk. No elevated risks were observed for husband smoking and use of heating apparatus so far.

We have reported that a combination of delipation (removal of cytoplasmic lipid droplets from blastomeres) and vitrification by means of the minimum-volume cooling (MVC) method successfully cryopreserves porcine in vitro-matured/fertilized (IVM/IVF) embryos, and that normal piglets are produced from these embryos (Hiruma et al. 2006 Reprod. Fertil. Dev. 18, 157). We have also reported that IVM-derived embryos that undergo noninvasive delipation (i.e. micromanipulation is not required) and vitrification develop into blastocysts at a high rate (Esaki et al. 2004 Biol. Reprod. 71, 432–437). In this study, we examined whether fetuses can be produced from the IVM-derived embryos that have been delipated noninvasively and vitrified. Cumulus–oocyte complexes that had been collected from slaughterhouse ovaries were in vitro-matured in NCSU23 medium. The IVM oocytes were activated to produce parthenogenetic embryos. We used the embryos at the 4- to 8-cell (67 h after activation) and morula (98 h) stages in the following experiments. Embryos were treated with 4% trypsin (in PBS) at 38�C for 1 to 4 min to expand the zona pellucida. Next, the embryos were centrifuged (12 000g, 38�C, 23 min) in TL-HEPES-PVP containing 7.5 �g mL-1 cytochalasin B to polarize cytoplasmic lipid droplets within the perivitelline space. These embryos were cultured for 1 to 3 h and then vitrified. The post-thaw viability of the embryos was assessed based on their ability to develop into blastocysts and fetuses (21 to 23 days old). The embryos were vitrified using the MVC method with 15% ethylene glycol, 15% DMSO, and 0.5 M sucrose as cryoprotective agents. PZM-5 was used for culturing the embryos. In embryo transfer experiments, after thawing, the embryos were cultured for 36 or 72 h until they developed into morulae or 4- to 8-cell blastocysts, respectively; they were then treated with 0.5% pronase to remove the zona pellucida, and transferred to the uterine horns of estrus-synchronized recipients 6 days after onset of estrus. The proportion of vitrified embryos that developed into blastocysts and the mean cell number of the blastocysts were similar to those of non-vitrified control embryos, irrespective of the embryonic stage (4- to 8-cell stage: 42.1%, 22/51, 63.0 � 7.8 vs. 64.7%, 22/34, 74.2 � 7.1, respectively; morula stage: 77.6%, 38/49, 69.6 � 7.2 vs. 83.3%, 45/54, 66.2 � 5.9, respectively). Seventeen embryos that had been vitrified at the 4- to 8-cell stage gave rise to 3 fetuses after transfer into one recipient (17.6%). Fifty-three embryos that had been vitrified at the morula stage were transferred into 3 recipients. All recipients became pregnant and produced a total of 17 fetuses (32.1%). These results suggest that porcine IVM-derived embryos that have been cryopreserved by the combination of noninvasive delipation and vitrification by the MVC method are highly viable.

We previously reported that transgenic (TG) pigs can be produced from in vitro-matured oocytes using intracytoplasmic sperm injection-mediated gene transfer (ICSI-mediated method) (Kurome et al. 2006 Transgenic Res. 15, 229–240). We subsequently studied the expression of a foreign gene which had been introduced by the ICSI-mediated method. We found that the ICSI-mediated method is considerably less likely than the pronuclear microinjection method to produce embryos in which transgene-positive and transgene-negative cells co-exist, that is, mosaic embryos (Saito et al. 2006 Reprod. Fertil. Dev. 18, 297 abst). Therefore, in order to further investigate the ICSI-mediated method, the present study was conducted to address the integration patterns of foreign genes introduced by this method. In particular, we wished to determine the number of transgene copies and number of chromosomal integration sites. TG pig fetuses, obtained by the ICSI-mediated method in a separate cardiac disease model study, were used in the present study. Porcine cumulus-oocyte complexes that had been collected from slaughterhouse ovaries were subjected to in vitro maturation in NCSU23 medium to produce MII oocytes to be used in this study. Porcine spermatozoa frozen in Beltsville Thawing Solution (BTS) were thawed rapidly in a 37�C water bath, and each spermatozoon was decapitated using ultrasound (28 kHz, 100 W; W-113; Honda Electronics Co., Ltd, Aichi, Japan). The heads (2 to 5 � 105/10 �L) were co-incubated with 2.5 ng �L-1 of rabbit calreticulin cDNA (�MHC-CRT-HA: 7.5 kb) for five min at room temperature, and then microinjected into MII oocytes using a piezo-micromanipulator. An electric stimulus (DC 150 V mm-1, 100 �s) was applied 10 to 40 min after microinjection in order to activate the oocytes. The embryos were cultured in PZM-5 medium for one to two days, and then transferred into the oviducts of recipient gilts, whose estrous cycle had been synchronized using 1000 IU eCG and 1500 IU hCG. Fetuses were collected 33 or 50 days later, and a primary cell line (fibroblast) was established. For each fetus, the number of transgene copies was determined by Southern blot. In addition, the chromosomal sites, where the foreign gene had integrated, were identified, and the number of integration sites was determined by fluoresent in situ hybridization (FISH). A total of 454 ICSI embryos were transferred to 4 recipients (92 to 135 embryos/recipient). All recipients became pregnant and 23 fetuses (5.1%, 23/454), including 7 TG fetuses (30.4%, 7/23), were obtained. Southern blot analysis showed that the number of transgene copies varied between 1 and 300 (1 copy: 1 fetus; 10 copies: 2 fetuses; 30 copies: 3 fetuses; 300 copies: 1 fetus). FISH analysis showed that in TG fetuses, the foreign gene had integrated at only a single chromosomal site, and this site varied from TG fetus to TG fetus. These results demonstrate that, in the case of ICSI-mediated gene transfer, as is the case for gene transfer by pronuclear microinjection, the integration patterns are: multiple copy, random site, and single site integration. This study was supported by PROBRAIN.

Cloned pigs that express cell markers such as fluorescent proteins (Vintersten et al. 2004 Genesis 40, 241–246) are useful in biomedical research in areas such as cell/tissue transplantation and regenerative medicine. In this study, we attempted to produce transgenic cloned pigs from porcine fetal fibroblasts which carry the gene of red fluorescent protein, humanized Kusabira-Orange (huKO). We examined whether huKO-transfected cells are suitable as nuclear donors for somatic cell cloning, and whether red fluorescence can be detected in the cloned embryos. We used porcine fetal fibroblasts transfected with the huKO gene and a retroviral vector as the nuclear donor cells. Non-transfected cells were used as the control. Cumulus–oocyte complexes collected from slaughterhouse ovaries were in vitro-matured in NCSU23 medium to produce recipient oocytes. Nuclear transfer was conducted using a previously reported method (Kurome et al. 2003 Cloning Stem Cells 5, 367–377); the following parameters which determine the overall efficiency of nuclear transfer were investigated: (1) fusion rate between the donor cells and recipient oocytes, (2) rates of normal cleavage and blastocyst formation of the NT embryos, and (3) cell numbers in each blastocyst. A DC pulse (190 V mm-1) was used for electric fusion, and NCSU23 or PZM-5 medium was used for culturing the cloned embryos. The NT embryos on Day 7 were examined under a fluorescence microscope (G excitation) in order to evaluate the expression of red fluorescence. Some cloned embryos at the 1- to 8-cell stage (Day 1 or 2) were transferred into oviducts of estrus-synchronized recipient gilts. There was no significant difference (chi-square test) between the huKO and the control groups in the rate of fusion (132/151, 87.4% vs. 134/147, 91.2%, respectively) and cleavage rate (78/132, 59.1% vs. 86/134, 64.2%, respectively). A significantly greater percentage of huKO cell-derived embryos developed into blastocysts than did control cell-derived embryos (37/132, 28.0% vs. 20/134, 14.9%, respectively; P < 0.05). However, there was no significant difference in the blastocyst cell numbers (Student's t-test: 48.6 ± 4.8 vs. 42.3 ± 4.9, respectively). Of the 132 NT embryos, 116 (87.9&percnt;) expressed red fluorescence. The percentage of blastocysts expressing red fluorescence was 94.6&percnt; (35/37). These results demonstrate that it is possible to obtain cloned blastocysts at a high rate by nuclear transfer of cells that have been transfected with huKO using a retroviral vector, and that it is possible to observe the expression of red fluorescence in cloned embryos. With respect to the cloned embryos that did not show expression of red fluorescence, we hypothesize that this was the result of a small proportion (

A non-quasi-static MOSFET model for circuit simulation, which is based on the carrier-transit delay responsible for the channel formation during switching on, has been developed. The developed model was implemented into a circuit simulator, and good agreement of transient drain current with 2D simulation results was confirmed.

Two glucosides of lindenane sesquiterpenes have been first isolated along with three known lindenane sesquiterpenes from Chloranthus glaber Makino and the structures were elucidated by spectroscopi...

We investigate the intrinsic current fluctuations in very small Si-metal-oxide-semiconductor field-effect-transistors (MOSFETs) using Monte Carlo device simulation. It is demonstrated that the temporal fluctuation of the drain current in small Si-MOSFETs attains a significant fraction of the averaged drain current when the device width is scaled down to the deep sub-µm regime. This enhancement of current fluctuation is caused by the drastic decrease in the number of channel electrons underneath the gate. It is also demonstrated that current fluctuation is physically associated with the quasi-equilibrium thermal noise in the heavily doped source and drain regions. More significantly, the current fluctuation is intrinsically unavoidable and could be a critical issue for further device shrinkage.

MnSb/Sb superlattice films containing ultrathin ferromagnetic MnSb layers (0.36–3.0 ML) have been investigated by magnetization measurements. Samples containing MnSb thinner than 3.0 ML show perpendicular magnetic anisotropy. Magnetization vs. temperature curves of samples with MnSb monolayers strongly depend on the external field.

Synchrotron radiation‐assisted etching of SiO2 in a hydrogen atmosphere and its application to pretreating and cleaning substrates prior to Si film deposition is discussed. Thermally oxidized SiO2 film is etched in irradiation by synchrotron radiation at about 500 °C. Its etch rate increases by a factor of two in a hydrogen atmosphere. SiO2 core electron excitation by such irradiation seems to play an important role in SiO2 film modification and etching. This treatment reduced the interface contaminants such as oxygen and carbon between the deposited film and substrate to levels below the detection limit of secondary ion mass spectroscopy. Our results demonstrate that this new process is effective for low‐temperature treatment.

Thermally grown SiO2 films were irradiated by synchrotron radiation at room temperature and changes in film properties were analyzed to clarify the irradiation effects and explain the mechanism of the photo-stimulated desorption (PSD) of SiO2. The irradiated SiO2 was chemically weakened throughout the film of 89-nm thickness by Si-O bond breaking following core electron excitation. The broken bonds were recombined by postannealing at 850°C. The irradiated surface was deoxidized by oxygen desorption and the remaining Si-rich layer was evaporated by postannealing over 700°C. Results indicate that irradiation effects are bond breaking and the desorption of oxygen and that thermal effects are the recombination of broken bonds and the evaporation of the deoxidized layer. It is supposed that the PSD of SiO2 at elevated temperature consists of photo-desorption of oxygen and thermal evaporation of SiO.

A silicon dioxide film was etched by synchrotron radiation (SR) irradiation at a substrate temperature of about 500°C. The obtained etching rate was 13 nm/h and the activation energy approximately 1.2 eV. This process was applied to remove surface contaminants on a silicon surface. Oxygen and carbon contaminants in the SR-irradiated area decreased by about 1/3 and 1/10, respectively, indicating that SR irradiation is effective for surface cleaning. A sharp peak in Raman spectrum appeared when a silicon film was deposited after SR irradiation. Thus, the pre-irradiation by SR improves the crystal quality of the deposited film.

A helium field ion source emits intense beams from a (111) plane protruding from a tungsten emitter. Gomer’s hopping model was expanded to explain the I–V characteristic of the plane. Our calculations agreed with the experimental results. To make a microprobe of helium ions, we constructed a 100 keV focusing column. It has a gimbal assembly and a phosphor screen with a microchannel plate to adjust the beam axis. Using a measured energy spread of 1 eV, the probe diameter was calculated to be less than 10 nm at a 1 pA probe current. Using scanning ion microscope images obtained with 90 keV helium ions, the actual probe diameter was estimated to be 2 μm. Although some improvements are necessary to focus the beam sharply, we showed the basic design of the focusing column for a helium field ion source.

The SrFeOx system with 2.5 ≤ x ≤ 3.0 was prepared and examined by differential thermal analysis, thermogravimetry, powder X-ray diffraction, and the 57Fe Mossbauer effect. Four single phases with different structures exist in this system, the typical compositions of which are SrFeO3, SrFeO2.86, SrFeO2.73, and SrFeO2.50. SrFeO2.86 and SrFeO2.73 have newly found tetragonal and orthorhombic structures, respectively, and their unit cells are related to the cubic perovskite cell for SrFeO3 in the manner that a t ≈ 2 × 2 1 2 a c , c t ≈ 2a c and a o ≈ 2c o ≈ 2 × 2 1 2 a c , b o ≈ 2a c , where the suffixes c, t, and o stand for the cubic, tetragonal, and orthorhombic structures, respectively. These single-phase compositions suggest the ideal series of SrFeO 3− 1 n , where n = ∞, 8, 4, and 2 give x = 3, 2.875, 2.75, and 2.50, correspondingly. The vacancy ordered phase of SrFeO2.86, SrFeO2.73, and SrFeO2.50 show first-order transitions to their cubic, disordered structures at 250, 320, and 830°C, correspondingly. Formation of the cubic, disordered structure above a temperature depending on the composition is suggested for the whole composition range.

To create submicrometer patterns with high accuracy on thick single-layer negative resist, error factors that degrade pattern accuracy have been investigated. Pattern accuracy was analyzed using a new evaluation method based on the difference between the resist development energy and the exposure energy at points on the edge of each shape. By introducing a new evaluation parameter, we were able to clarify error factors from the exposure conditions, the proximity effect correction method, and the machine exposure fluctuation. The evaluation parameter K is Q/Q_{0} where Q is the exposure dose appropriate for the desired resist thickness and Q 0 is the interface gel dose. It was found that the resist resolution and the rounding error of the exposure dose were serious error factors, especially in delineation on submicrometer patterns. To achieve 0.5-µm patterns with ±0.1-µm accuracy on 1-µm-thick negative resist, the resist evaluation parameter K must be less than 2, the rounding error of the exposure dose must be less than 2.5 percent of the dose, and the beam addressing unit (LSB) must be less than 0.025 µm.

Ferromagnetic resonance (FMR) of multilayered metallic films synthesized from an insoluble combination of Fe and Mg is studied in a temperature range from 10 K to 300 K. A well defined FMR signal is observed in each sample with Fe thickness ranging from 4 A to 30 A. The observed spectra are found to be strongly dependent on the regularity of the layered structure. The resonance field exhibits an unusual shift which changes systematically as a function of the thickness as well as temperature. The origin of the shift of the resonance field is discussed in relation to the amorphous-like structure observed for the thickness less than 12 A.

A new superlattice composed of semiconducting PbSe and SnSe has been grown epitaxially on cleaved NaCl substrates by the vapor deposition method. The samples were characterized by x‐ray diffraction and cross‐sectional high‐resolution transmission electron microscopy. Two materials have different crystal structures; PbSe has the cubic NaCl‐type structure, whereas SnSe has the orthorhombic SnS‐type structure, which is a distorted NaCl‐type structure. The lattice mismatch between them is quite large, about 3%, and their growth planes have different symmetries. Therefore, this superlattice should not be classified as an ordinary superlattice like the GaAs‐AlAs system, but as a so‐called strained‐layer superlattice. As a result of the structural analyses, it has been found that the samples have an ideal structure whose compositional modulation can be described by the step model with no mixed layers at the interface. In addition, we have observed a change of crystal symmetry in the PbSe layers: PbSe adopts the ...

Multilayered films are prepared by the alternate deposition of Mn and Sb in ultrahigh vacuum. On deposition, Mn atoms react with Sb atoms to form a ferromagnetic compound MnSb at the interface. The MnSb layers grow epitaxially on thick Sb layers. By utilizing this epitaxy, ultrathin (less than 10A) MnSb layers are sandwiched between thick (50A) Sb layers. The resulting superlattice films are ferromagnetic even when each MnSb layer thickness is less than 5A.

Shattered crystallites of Ba 3 Fe 1+x S 5 ( 1 3 ≤ x ≤ 2 5 ) were examined by electron microscopy. Both β-Ba9Fe4S15 (x = 0.333) and Ba15Fe7S25 (x = 0.40), previously reported members of Ba3pFeqS5p series, were identified by electron diffraction patterns, and supercell periodicities, 25.5 A ( ⋍3a 0 ) and 42.0 A ( ⋍5a 0 ), respectively, were resolved as lattice fringes. Some crystals with intermediate compositions showed electron diffraction patterns with diffuse superlattice reflections. Their lattice fringe patterns showed a microscopic disordered intergrowth structure consisting of three periodicities, 3a0, 5a0, and 4a0. The intergrowth structure is a disordered one and can be analyzed based on the one-dimensional disorder model of Fe occupation in the hexagonal rings of the Ba3S5 framework. It is also characteristic of the “microsyntactic” intergrowth.

Magnetic susceptibilities of Ba2FeS3, Ba2CoS3, and Ba2MnS3 show rounded maxima at 130, 125, and 100 K, respectively, which are due to quasi-one-dimensional antiferromagnetic short-range ordering. Intrachain interactions, J k , are estimated to be −20, −15, and −12 K, respectively. 57Fe Mossbauer spectra of Ba2FeS3 and 57Fe-doped Ba2CoS3 and Ba2MnS3 at 4.2 K show long-range antiferromagnetic ordering, due to the interchain interaction. The profile of Mossbauer spectra at 4.2 K is analyzed based on the coexistence of magnetic hyperfine and quadrupole interactions, and magnetic hyperfine fields at 4.2 K are estimated to be 36, 29, and 59 kOe, respectively.

A 55 Mn NMR investigation has been made on the interface magnetism in Fe/Mn artificial metallic superlattice (AMS). The signal associated with the ferromagnetically ordered Mn sites was observed in a wide frequency range. The chemical composition profile was extracted from the distribution of 55 Mn internal fields, and it is suggested that the compositional mixing occurs over a wide range (at least 15 A) near the interface in Fe/Mn AMS. From this, the interface alloy region was found to be ferromagnetic even in the Mn dense region, which cannot be expected for FeMn alloys in the thermal equilibrium. Thus it is concluded that a new-type alloy is created near the interface in the Fe/Mn AMS by making multilayers.

The system SrFeOx, 2.5 ≤ x ≤ 3, forms a continuous solid solution at temperatures T ≥ Tt(x), but a series of discrete ordered-vacancy phases SrFeO 3−( 1 n ) (n = ∞, 8, 4, 2) below temperatures Tt(n = 8) = 523 K, Tt(n = 4) = 598 K, and Tt(n = 2) = 1103 K. The most probable vacancy-ordering schemes for Sr8Fe8O23 (n = 8) and Sr4Fe4O11 (n = 4) are proposed. Formation of fivefold-coordinated iron sites on either side of an oxygen vacancy is characteristic of both phases, which contrasts with Sr2Fe2O5 (n = 2) where four-coordinated sites coexist with six-coordinated sites. The high-spin Fe 4+ (t 3 2 σ∗ 1 ) configuration of SrFeO3 (n = ∞) evolves as follows: (a) for x ≈ 3, random vacancies trap Fe3+ ions at five-coordinated sites; (b) for n = 8, Fe4+ ions remain high spin, a localized-electron 5Eg configuration giving rise to a cooperative Jahn-Teller distortion with c a ≤ 1 and a [220]n8 unique axis imposed by structural symmetry; fast Fe3+ + Fe4+ = Fe4+ + Fe3+ electron transfer occurs parallel to this axis at room temperature, but Fe3+ ions are ordered at five-coordinated sites at 4 K; (c) for n = 4, the octahedral-site Fe4+ ions have a low-spin t42 configuration with four near-neighbor Fe3+ ions in five-coordinated sites not making an Fe3+OFe4+OFe3+ linear chain as in n = 8. Oxygen-vacancy hopping times τh ≥ 10−8 sec persist for 200 K above Tt in n = 2, and short-range ordering in this temperature interval is inferred. For n = 8 and n = 4, motional narrowing to a single Mossbauer peak occurs within tens of degrees above Tt, and this narrowing is assumed to reflect rapid electron hopping in a mixed-valence state; this electronic motion masks any line narrowing due to oxygen-vacancy mobility in these phases.