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21.
Silver-catalyzed MnO2 has been found to be a good hydrogen absorber. The hydrogen absorber can be prepared either by mixing battery grade MnO2 and 1–10% Ag2O or AgO powder or by mixing the MnO2 and AgNO3 solution. The hydrogen gas absorption is a reaction between MnO2 and the H2 gas. Performance and characteristics of the silver-catalysed hydrogen absorber are described in relation to the preparation conditions and the silver content.  相似文献   
22.
Roles of water for chemical reactions in high-temperature water   总被引:3,自引:0,他引:3  
Akiya N  Savage PE 《Chemical reviews》2002,102(8):2725-2750
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23.
Osteoclasts, which resorb the bone, and osteoblasts, which form the bone, are the key cells regulating bone homeostasis. Osteoporosis and other metabolic bone diseases occur when osteoclast-mediated bone resorption is increased and bone formation by osteoblasts is decreased. Analyses of tyrosine kinase Src-knockout mice revealed that Src is essential for bone resorption by osteoclasts and suppresses bone formation by osteoblasts. Src-knockout mice exhibit osteopetrosis. Therefore, Src is a potential target for osteoporosis therapy. However, Src is ubiquitously expressed in many tissues and is involved in various biological processes, such as cell proliferation, growth, and migration. Thus, it is challenging to develop effective osteoporosis therapies targeting Src. To solve this problem, it is necessary to understand the molecular mechanism of Src function in the bone. Src expression and catalytic activity are maintained at high levels in osteoclasts. The high activity of Src is essential for the attachment of osteoclasts to the bone matrix and to resorb the bone by regulating actin-related molecules. Src also inhibits the activity of Runx2, a master regulator of osteoblast differentiation, suppressing bone formation in osteoblasts. In this paper, we introduce the molecular mechanisms of Src in osteoclasts and osteoblasts to explore its potential for bone metabolic disease therapy.  相似文献   
24.
25.
Co-polymerization of dialkynylbenzene with benzenedithiol proceeds regio- and stereoselectively in the presence of transition metal catalysts, affording the corresponding poly(phenylene vinylene sulfide) in good yield. In the presence of palladium acetate as catalyst, Markovnikov addition takes place selectively, whereas chlorotris(triphenylphosphine)rhodium-catalyzed reaction affords anti-Markovnikov adduct with excellent regio- and stereoselectivity.  相似文献   
26.
Smooth muscle differentiation in the ovary is rare, and its histopathologic spectrum, including ovarian smooth muscle metaplasia (SMM), has not been well described. The clinicopathologic findings in 48 ovaries with SMM from 40 women are reported. The average age of women with ovarian SMM was 55.6 years (range, 34 to 86 years). Foci of SMM were semiquantitatively characterized as 1+ in 46% (1 to 3 foci), 2+ in 37% (4 to 6 foci), and 3+ in 17% (> 6 foci). SMM was bilateral in 8 (23%) of the 35 patients who had bilateral oophorectomies. SMM was intimately associated with another ovarian process in 28 (58%) cases, including ovarian cysts (11), endometriosis (3), granulosa cell tumors (3), extensive stromal luteinization (1), ovarian fibroma (1), adhesions (1), and folliculogenesis (8). Ovaries with 2+ to 3+ SMM were associated with another ovarian lesion significantly more often than those with 1+ SMM (p < 0.01). Most women with ovarian SMM (86%) also had uterine leiomyomas. Significant endometrial pathology was present in 13 (37%) of 35 simultaneously removed uteri. In conclusion, SMM occurs most often in perimenopausal or postmenopausal women, most of whom also have uterine leiomyomas. Ovarian SMM is usually confined to a few microscopic fields, is bilateral in < 25% of patients, and is often associated with other ovarian lesions.  相似文献   
27.
Nakashima  S. Akiya  M. Kato  K. 《Electronics letters》1983,19(15):568-570
The electric-field-shielding effect was found in a layer consisting of a mixture of polycrystalline silicon and silicon oxide formed by oxygen ion implanatation. The layer was formed between the buried SiO2 and the upper Si layer, which improved characteristics for MOSFETs fabricated using SIMOX (separation by implanted oxygen) technology. By forming this layer, the threshold voltages for the MOSFETs were almost independent of substrate bias. Drain-to-source breakdown voltages for the p-MOSFETs and n-MOSFETs were raised to 250 V and 180 V, respectively.  相似文献   
28.
PURPOSE: Our purpose was to assess the effect of cryopreservation on cytoskeleton of germinal vesicle (GV) mouse oocytes and determine whether irreversible spindle damage and related digyny associated with cryopreservation of metaphase II (MII) oocytes can be avoided. METHODS: The GV oocytes were cryopreserved using a slow-cooling (0.5 degree C/min) and slow-thawing (8 degrees C/min) protocol in 1.5 M dimethylsulfoxide supplemented with 0.2 M sucrose and analyzed before and during fertilization by multiple-label fluorescence and differential interference contrast microscopy techniques. RESULTS: When examined after in vitro maturation, the vast majority (> 95%) of cryopreserved and control oocytes displayed normal microfilament and microtubule organization. With respect to barrel-shaped spindle and normal chromosome alignment, no significant differences were observed between cryopreservation (78 and 86%, respectively) and control (85 and 95%, respectively) groups. In fertilization experiments, spindle rotation, formation of the second polar body, and pronuclear migration were displayed by similar percentages of cryopreserved (96, 94, and 37%, respectively) and control (98, 97, and 45%, respectively) oocytes, indicating normal functionality of the cytoskeleton during this period. However, pronuclear formation was significantly inhibited by cryopreservation (81%) compared with controls (100%). Regarding digyny and polyspermy, no significant increase was observed after cryopreservation (3 and 10%, respectively) compared with controls (3 and 6%, respectively). CONCLUSIONS: Cryopreservation of mouse oocytes at the GV stage is particularly advantageous to circumvent the spindle damage and increased digyny noted after cryopreservation of MII oocytes.  相似文献   
29.
We present a method for analyzing several common cell failures in SRAM's, i.e., failures caused by defects produced during VLSI processing. Faults, in 64 k-bit CMOS SRAM's with six-transistor type cells used in this study, are classified in terms of the number of faulty cells. Single-cell and adjacent cell faults, which are dominant, are due to blocked contact holes, aluminum 1 short-circuit defects and blocked via holes. A vector plot showing the relation between single-cell and adjacent-cell failure probabilities suggests that blocked contact holes, aluminum 1 short-circuit defects, and blocked via holes can be isolated. This vector representation is useful in monitoring and improving fabrication yields of VLSI circuits. Vector representations are also given for three and four-cell failure probabilities  相似文献   
30.
Polymeric micelles that are composed of synthetic polymers are generally size controllable and can be easily modified for various applications. Lactosomes (A3B-type) are biodegradable polymeric micelles composed of an amphipathic polymer, including three poly(sarcosine) blocks and a poly(l-lactic acid) block. Lactosomes accumulate in tumors in vivo through the enhanced permeability and retention (EPR) effect, even on frequently administering them. However, lactosomes cannot be efficiently internalized by cells. To improve cellular uptake of lactosomes, cell-penetrating peptide (CPP)-modified lactosomes were prepared. Seven CPPs (including EB1 and Pep1) were used, and most of them improved the cellular uptake efficiency of lactosomes. In particular, EB1- and Pep1-modified lactosomes were efficiently internalized by cells. In addition, by using CPP-modified and photosensitizer-loaded lactosomes, we demonstrated the photoinduced killing of mammalian cells, including human cancer cells. Accumulation of the EB1-modified lactosomes in NCI-N87 tumors was shown by in vivo imaging. Thus, this study demonstrated that the CPP-modified lactosome is a promising drug carrier.  相似文献   
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