This study was undertaken to determine the relationship between the first division of in vitro produced (IVP) bovine embryos and the following few divisions in culture. The “early-”, “intermediate-“ and “late-” cleaving embryos presented at 22, 26 and 30 h post insemination (hpi) were cultured separately until they were fixed and stained with Hoechst 33342 at the end of each culture period (30, 48, 72, 96 and 120 hpi). Distributions of embryos that underwent the first at 22, 26 and 30 hpi were 21.5, 34.7 and 10.0%, respectively. No significant difference among the mean number of cells in the 3 groups was observed until 48 hpi. At 72 hpi, the number of cells in the early-cleaving embryos (10.8 ± 0.5) was higher than those in the intermediate- and late-cleaving embryos (8.7 ± 0.4 and 6.5 ± 0.6, respectively). Higher numbers of cells were also observed in the early-cleaving embryos (18.0 ± 1.5) at 120 hpi, compared with those in the intermediate- and late-cleaving embryos (12.5 ± 0.8 and 11.4 ± 1.5, respectively). More than 80% of the early- and intermediate-cleaving embryos had completed the second division at 48 hpi, whereas that of the late-cleaving embryos was lower (56.5%). No difference in the proportion of >8-cell embryos among the 3 groups was observed at 48 hpi (22.9 vs 24.7 vs 26.1%). However, the completion of the third in the early-cleaving embryos was higher than in the intermediate- and late-cleaving embryos at 72 hpi (65.4 vs 49.4 vs 25.0%), and from there onwards (96 hpi; 81.1 vs 63.2 vs 45.5%, 120 hpi; 83.6 vs 62.2 vs 65.0%). The proportion of >16-cell embryos in the early-cleaving embryos was also higher than that of the intermediate- and late-cleaving embryos between 96 hpi (18.9 vs 2.9 vs 0.0%) and 120 hpi (49.1 vs 22.0 vs 25.0%). Our results suggest that the development of IVP bovine embryos is possibly controlled as early as at the 2-cell stage, and the differences between the early and late cleaving embryos are associated with 1) the developmental delay or arrest of embryos during the second , and 2) the lengthening of the third , which seems to be related to the subsequent developmental ability of the embryos.

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The developments of strain markings produced in polycrystalline zinc by thermal cycles between room temperature and −196°C have been observed after each cycle. There is clear microscopic evidence that twins may be initiated by the high local stresses produced round the tip of crack. Some of the twins initiated by crack are seen to become lens-shaped twins separated from the crack after further cycles, but others spread or shrink along the crack with cycles. Some of the cracks being arrested at grain boundary initiate twins or kinks in the next grain. No twin initiates the crack. Many examples have been observed of cracks being arrested at a pre-existing twin boundary, but most of the cracks propagate across the twin after further cycles. Micro-kinks also may be produced at the tip of cracks, and many examples of micro-kinks along cracks were observed.

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The c-Jun N-terminal kinases (JNKs) are a subfamily of MAPKs. The JNKs are encoded by three separate genes (jnk1, jnk2, and jnk3), which are spliced alternatively to create ten JNK isoforms that are either p46 or p54 in size. We found that the p52 form of JNK emerged in MOLT-4 or U937 cells following X-irradiation or heat treatment. The accumulation of p52 coincided with the reduction of p54 JNK, while, the amounts of p46 JNK did not change by X-irradiation. Induction of the p52 JNK also paralleled the appearance of the active form of caspase-3, and was suppressed by a caspase-inhibitor, Ac-DEVD-CHO, but not by Ac-YVAD-CHO. In vitro assays indicated that recombinant JNK1 beta 2 was cleaved by caspase-3, and that the mutation of aspartic acid at position 413 of JNK1 beta 2 to alanine abolished the . Our results demonstrated that p54 JNKs were new selective targets of caspases, and suggested that the p52 form could serve as an apoptotic marker. [J Radiat Res 44:445 (2003)]

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We chanced on a slice of mica which was cleaved spirally. The spiral lamella was several hundredths mm thick. Detailed observations on the structure of this specimen including polarization microscopic and X-ray studies are described. A tentative explanation of the origin of this unusually thick growth-layer is proposed assuming that an external force, which was exerted during the formation of the crystal, caused the left and right halves of the crystal to make a small relative rotation around the a-axis.

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A reaction of chemical bonds connecting between aromatic clusters in coal was investigated. We conducted the heat-treatment of coals or coal model compounds in the presence of a hydrogen donor at 380-420°C for 5-60 min in a sealed tube. As the hydrogen donor, 9, 10-dihydroanthracene (DHA) or 9, 10-dihydrophenanthrene (DHP) was used. In the reaction of coal with hydrogen donor at 420°C for 5 min, larger amounts of hydrogen were consumed for DHP than for DHA. Bond reactions using several model compounds showed that the yields of homolytically cleaved products were higher than those of ipso position cleaved products. This is reasonable in terms of their bond dissociation energies. On the other hand, ipso position reaction was preferable in the presence of DHP. As the results, it is considered that ipso position reaction has an important contribution to the reaction of coal with DHP at relatively higher temperature. Since the model compounds having dimethylene bridge are considered to represent polymethylene bridge bonds, monomethylene is believed to be a significant bridge bond which governs the coal reactivity.

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TEM in-situ indentation experiments were applied to directly observe the atomic structures on the planes of sapphire, and the structures were determined by HRTEM image simulation. It was found that cracks mainly propagate along the low index planes of sapphire, forming the atomic scale steps on the planes, and the atomic structures are dependent on the crystal orientation. In addition, the surface structures of the planes were found to be reconstructed in the vicinity of the respective surfaces. For the (1120) plane, the surface is composed of Al–O–Al cluster to form the complicated and metastable Al rich surface.

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The relation between the steps and dislocation etch pits patterns was examined by comparing step patterns and dislocation etch pit patterns in KCl crystals. The following specimens were used in this study; (1) pure crystal, (2) Sr-doped crystal (0.013 at.%), (3). Sr-doped crystal (0.03at.%), (4) Ca-doped crystal (0.02 at.%). Special attention was paid to the effects of impurities and temperature on the step pattern. The results obtained are as follows: (1) Ripple markings (see the section 3) were observed on the cleaved surfaces in all crystals examined in this work, but dislocation nucleation at the ripple markings was strongly affected by the impurities. (2) When the dislocations were nucleated at the ripple markings, a number of steps were newly generated there. (3) The straightness of the step lines was strongly dependent on the homogeneity of the dislocations and/or impurities in the crystals. (4) No effect of temperature on the step pattern was found in the experiment in liquid nitrogen.

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The macroscopic plane of TGS at the ferroelectric phase is slightly inclined to the b-plane when the propagating direction is roughly along the c-axis. The sense of the inclination is reversed with the direction of the propagation and with the polarity of domain. The microscopic structure of the surface was examined by electron microscopy utilizing the low angle shadow decoration technique. This technique revealed the detail of the surface on the crystallographic unit cell scale. The macroscopic inclination results from the formation of elementary steps of b₀ in height, where b₀ is the unit cell length along the b-axis. The steps are bent at domain boundaries to one particular side determined by the polarity of domain and the direction. The elementary step formation and the step bending at domain boundaries are interpreted by assuming that the bonding on the positive side of the crack front is more easily broken than that on the negative side. There is one particular direction in which steps of b₀/2 in height are formed. The surface discontinuity of b₀/4 or less were observed at domain boundaries. Such a characteristic surface structures are discussed in relation to the crystal symmetry of TGS. The plane in the unit cell is the positive side of the layer composed from SO₄ and glycine I at y=1/4 or 3/4.

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The following selection markers for in vitro-produced porcine embryos were investigated: the timing, pattern and evenness of the first and the timing of the second . The embryos that cleaved by 30 h post-insemination (hpi) developed to blastocysts at a significantly higher rate (60.9%) and with a significantly higher cell number (33.6 cells) than those of embryos cleaved by 36 hpi (26.4% and 23.6 cells, respectively, P<0.05). Blastocyst proportions derived from 2- and 3-cell embryos cleaved by 30 hpi (68.2 and 65.3%, respectively) were significantly higher than those of 4- and >4-cell embryos (46.3 and 42.6%, respectively, P<0.05). The cell number per blastocyst generated from 2-cell embryos was significantly greater (37.3 cells) than those from 3-, 4- and >4-cell embryos (23.6-27.8 cells, P<0.05). Among embryos cleaved by 30 hpi, the blastocysts derived from evenly cleaved embryos (40.6 cells) were of significantly better quality than those derived from unevenly cleaved embryos (33.2 cells, P<0.05), although their blastocyst rates did not differ. The evenly cleaved embryos that underwent subsequent within 18 h had significantly higher blastocyst rates (72.7-81.0%) and quality (36.2-40.9 cells) than those without subsequent (48.3% and 22.5 cells, respectively, P<0.05) during the same period. In conclusion, the timing, pattern and evenness of the first and the timing of the second affected the developmental competence and quality of in vitro-produced porcine embryos.

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日本, スウェーデン, ケニアの3カ国で分離された疫学的に関連のない, それぞれ104, 68, 32株, 計204株のHSV 1分離株について4種の制限酵素 (BamH I, Kpn I, Sal I, Hind III) を用いてゲノムを比較した。4制限酵素による130の切断点のうち27の切断点において, 3カ国のうち, いずれかの2カ国間で有意差が認められた。すなわち, 日本とスウェーデン間で17, 日本とケニア間で22, スウェーデンとケニア間で17切断点に有意差が認められた。27切断点の変異による断片のうち, 特定の1カ国の分離株にのみ存在する, または, 存在しない断片が合計20認められた。21切断点の変異をパターン化し204株のHSV 1株を分類したところ92の異なる切断パターンに分類され, ケニア株1, スウェーデン株2株に共通した1パターンを除いて, それぞれの国の分離株は異なる切断パターンに分類された。以上の結果は地理的または人類学的に離れた国または人種間では, 分布しているHSV 1のゲノム構造が極めて異なることを示唆している。

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Bond reactions of the bridge structure in coal are known to be key steps for coal conversion like liquefaction, carbonization, and so on. In the present study, we investigated two kinds of bond reactions, homolytic of dimethylene and ether bonds, and ipso-position of mono- and dimethylene bonds in the presence of hydrogen donor solvent (9,10-dihydroanthracene and 9,10-dihydrophenanthrene). The results suggest that reaction at ipso-position is also important at temperature range around 420℃.

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Peptide bond cleavages by vapors composed of various from aqueous solutions of perfluoric acid were studied using synthetic peptides and proteins, and specific conditions were established for peptide bond cleavages including a novel of the glycyl-threonine bond. The peptide bonds on the aminosides of serine residues were cleaved by exposure to a vapor of 75% aqueous heptafluorobutyric acid at 30 or 50°C for 24h. Glycyl-threonine peptide bonds were cleaved with vapors of various concentrations (5, 75, and 90%) of heptafluorobutyric acid at 30-40°C for 24h. The peptide bonds on the carboxylsides of aspartic acid residues were cleaved by exposure to a vapor of 0.2% heptafluorobutyric acid at 90°C for 4 to 24h. The same vapor cleaved aspartyl-proline bonds under milder conditions such as at 60°C for 16h, under which the other aspartyl bonds were uncleaved. These specific chemical cleavages were applied to several proteins including newly characterized proteins.

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