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21.
Amines and boranes are the archetypical Lewis bases and acids, respectively. The former can readily undergo one-electron oxidation to give radical cations, whereas the latter are easily reduced to afford radical anions. Here, we report the synthesis of a neutral tricoordinate boron derivative, which acts as a Lewis base and undergoes one-electron oxidation into the corresponding radical cation. These compounds can be regarded as the parent borylene (H-B:) and borinylium (H-B(+.)), respectively, stabilized by two cyclic (alkyl)(amino)carbenes. Ab initio calculations show that the highest occupied molecular orbital of the borane as well as the singly occupied molecular orbital of the radical cation are essentially a pair and a single electron, respectively, in the p(π) orbital of boron. 相似文献
22.
Hideyuki KANEMOTO Rei MORIKAWA James Kenn CHAMBERS Koichi KASAHARA Yasuko HANAFUSA Kazuyuki UCHIDA Koichi OHNO Hiroyuki NAKAYAMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):715-719
A Pomeranian dog, 1 year- and 8 month-old neutered female, was presented with persistent
respiratory distress and recurrent generalized demodicosis. Physical examination revealed
cyanosis, rough respiratory sounds, multifocal alopecia and dermal erosions on the dorsal
side of the forelimbs, perineal area and skin around the eyes. A severe diffuse
interstitial lung pattern was observed on thoracic radiographs. The blood examination
revealed neutrophilia and hypoglobulinemia. Serum immunoglobulin concentrations of IgG and
IgA were low. Histopathological examination revealed severe diffuse interstitial pneumonia
with Pneumocystis carinii infection. Severe lymphoid depletion was
observed in the spleen and other organs with lymphoid follicles consisted mainly of
CD3-positive T cells and few cells of B-cell lineage. B-cell hypoplasia with subsequent
antibody deficiency was suspected. 相似文献
23.
本文综述了压电晶体化学传感器在气相、液相物质和生物学上的应用,介绍了压电晶体化学传感器的新型装置(如传感器阵列)、新型敏感材料. 相似文献
24.
Jie Liu Ryo Ando Kuniyoshi Shimizu Koh Hashida Rei Makino Seiji Ohara Ryuichiro Kondo 《Journal of Wood Science》2008,54(1):68-75
In humans, steroid 5α-reductase is involved in the development of benign prostatic hyperplasia (BPH). We tested the steroid
5α-reductase inhibitory activity of the 70% acetone extract of woody plants. The tannin polymer prepared from the 70% acetone
extract showed the highest steroid 5α-reductase inhibitory activity. Furthermore, the steroid 5α-reductase inhibitory activity
of tannins was not affected by the addition of superoxide dismutase or catalase. It was concluded that the steroid 5α-reductase
inhibitory activity of condensed tannin was caused by binding to the steroid 5α-reductase, rather than from the peroxide/superoxide
produced by tannins. The tannins, prepared from tree barks, with potential for steroid 5α-reductase inhibitory activity might
be advantageous in therapy for steroid 5α-reductase diseases such as BPH or prostate cancer.
Part of this report was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004 相似文献
25.
26.
The reaction of 2,2,3,3-tetrabromo-1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasilane with four equivalents of potassium graphite (KC8) in tetrahydrofuran produces 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyl-2-tetrasilyne, a stable compound with a silicon-silicon triple bond, which can be isolated as emerald green crystals stable up to 100 degrees C in the absence of air. The SiSi triple-bond length (and its estimated standard deviation) is 2.0622(9) angstroms, which shows half the magnitude of the bond shortening of alkynes compared with that of alkenes. Unlike alkynes, the substituents at the SiSi group are not arranged in a linear fashion, but are trans-bent with a bond angle of 137.44(4) degrees. 相似文献
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28.
Rei HIRATA Takuo HOJO Masahiro SANO Nobuyoshi HAYASHI Kiyoshi OKUDA 《The Journal of reproduction and development》2015,61(1):67-73
The corpus luteum (CL) forms after ovulation and acts as a temporary endocrine gland that produces progesterone (P4), a hormone that is essential for implantation and maintenance of pregnancy in mammals. In pregnant women, human chorionic gonadotropin (hCG) secreted by the conceptus prevents luteolysis. hCG also increases the survival of cultured human luteinized granulosa cells (hLGCs). To clarify the maintenance mechanism of the human CL, we investigated the effects of hCG and P4 receptor antagonists, onapristone (OP) and RU486, on the viability of hLGCs. With the patients’ consent, hLGCs were isolated from follicular aspirates for in vitro fertilization. The cells were cultured with hCG (0.1, 1, 10, 100 IU/ml), OP (10, 25, 50, 100 μM), RU486 (100 μM), P4 (1, 10, 25, 50 μM) or some combination of the four for 24 h. Cell viability was significantly increased by hCG (100 IU/ml) and significantly decreased by OP (100 μM) compared with the control. Cells
treated with hCG and OP together were significantly less viable than the control and OP-treated cells. The combined treatment also significantly increased CASP3 activity and cleaved CASP3 protein expression. Furthermore, P4 addition reversed the reduction in cell viability caused by the combination of hCG and OP treatment. The overall findings suggest that hCG cooperates with P4 to increase survival of hLGCs and to induce apoptosis when P4 action supported by hCG is attenuated in the human CL. 相似文献
29.
回归分析确定土地质量评价因素权重的探讨 总被引:1,自引:0,他引:1
刘锐 《西南大学学报(自然科学版)》1987,(4)
以土种为基本单元统计资料,采用多元回归分析法定量确定土地评价因素的权重,是一种新的尝试。该方法比传统的经验更具有科学性。同时,由于各地在土壤普查中积累了丰富的土种资料,此种方法也容易为基层掌握。以土种为基本单元统计资料,可以把因变量和自变量由于统计数据的误差缩小在土种范围,因而可以提高因变量和自变量的相关总体效果,从而提高评价的精度。确定好土种基本产量是该方法的关键。 相似文献
30.
Matsuwaki T Asakura R Suzuki M Yamanouchi K Nishihara M 《The Journal of reproduction and development》2011,57(1):113-119
The progranulin (PGRN) gene is involved in sexual differentiation of the brain during the perinatal period and estrogen-induced adult neurogenesis in the hippocampus. Mutations in the PGRN gene are also implicated in human frontotemporal lobar degeneration. Thus, while PGRN appears to play important roles as a growth factor in the brain, the localization of PGRN-expressing cells throughout the brain has not been fully established. In the present study, we examined the localization of PGRN proteins in the brain using adult male wild-type mice and PGRN-deficient mice we had generated previously. We also evaluated age-dependent changes in PGRN expression at the mRNA and protein levels. As expected, no immunoreactivity was observed in the brains of the PGRN-deficient mice. In the wild-type mice, intense immunoreactivity was observed in several brain regions including the cingulate and piriform cortices, the pyramidal cell layer and dentate gyrus of the hippocampus, the amygdala, the ventromedial and arcuate nuclei of the hypothalamus and the Purkinje cell layer in the cerebellum. Moreover, PGRN mRNA and protein expression decreased in the cortex, hippocampus and hypothalamus in an age-dependent manner. Since many of these brain regions are involved in emotion, memory and recognition, PGRN may play roles as a growth factor in these brain functions that decline with age. 相似文献