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191.
Successful production of blastocysts following ultrarapid vitrification with step-wise equilibriation of germinal vesicle-stage mouse oocytes 总被引:4,自引:0,他引:4
Aono N Naganuma T Abe Y Hara K Sasada H Sato E Yoshida H 《The Journal of reproduction and development》2003,49(6):501-506
The purpose of this study was to evaluate the viability and subsequent developmental ability of murine germinal vesicle (GV) oocytes ultrarapidly vitrified after step-wise exposure to cryoprotectants (CPAs). Oocytes were transferred to a vitrification solution composed of 15% ethylene glycol, 15% dimethyl sulfoxide and 0.5 M sucrose in a direct manner (non-preequilibrium) or in a step-wise manner (single-, two-, or ten-step preequilibrium). After ultrarapid vitrification and storage in liquid nitrogen, the oocytes were thawed, washed by diluting the CPAs in five steps, and then subjected to in vitro maturation, fertilization and culture. In the non-preequilibrium group, the rates of post-thawed oocytes surviving, maturing to metaphase-II, developing to blastocysts and to hatching/hatched blastocysts were 91.8, 87.1, 15.9 and 2.3%, respectively. In the single- and two-step groups, the corresponding rates were 97.0-98.2%, 92.2-95.0%, 22.0-29.4% and 8.8-15.6%, whereas in the ten-step group they were 98.2, 91.8, 38.6 and 22.8%, respectively. In the non-vitrified control group, the rates of oocytes maturing to metaphase-II, developing to blastocysts and to hatching/hatched blastocysts were 90.2, 75.2 and 51.5%, respectively. The present study shows that the ultrarapid vitrification of murine GV oocytes by a step-wise manner involving 10 steps preequilibrium may have an advantage in maintaining the viability and subsequent production of blastocysts. 相似文献
192.
193.
De-Ling Ma Yoshito Suzuki Hiroaki Takeuchi Tomonari Watanabe Mami Ishizaki 《Phytoparasitica》2005,33(5):506-514
Two extracts from neem (Azadirachta indica A. Juss. (Meliaceae)) seeds, azadirachtin and oil, and a mixture of neem oil and abamectin, were tested on second-instar
nymphs of the rice bugLeptocorisa chinensis (Dallas) (Hemiptera: Alydidae). To clarify the effect of spraying coverage on bioefficacy of test materials, experiments
were conducted under choice and no-choice conditions in field cages. In a choice test, treatment with the mixture of neem
oil and abamectin was most effective in reducing the survival ofL. chinensis, followed by azadirachtin at 60 ppm, 30 ppm and 3% neem oil, whereas all treatments except neem oil caused 100% mortality
within 3 weeks in a no-choice test. When second-instar nymphs had choices of treated and untreated plants within a treatment,
no differences in yield and sum of dead and stained grains were found between those two choices, indicating that nymphs neither
caused significant reduction in yield nor reduced the quality of untreated plants. Regardless of treatment, the difference
in overall yield between treated and untreated plants under choice conditions was not statistically significant (P>0.05). Our results indicate that neem-based formulations, used alone or in combination with abamectin, have the potential
to be integrated into the existing programs to control the rice bug.
http://www.phytoparasitica.org posting Aug. 28, 2005. 相似文献
194.
AIM: To investigate the angiogenesis status,the expression of vascular endothelial growth factor (VEGF),angiopoietin-1 (ANG-1),angiopoietin-2 (ANG-2),thrombospondin-1 (TSP-1) in cholangiocellular carcinoma (CCC) and relationship with tumor angiogenesis,differentiation,invasion and metastasis.METHODS: 33 specimen of surgically resected CCC were investigated.Immunohistochemical staining of CD34,VEGF,ANG-1,ANG-2 and TSP-1 was carried out.RESULTS: The mean MVD was (87.2±52.6)/mm2.VEGF positive expression was found in 75.6% cases;ANG-1 positive expression was observed in 36% cases;ANG-2 positive was detected in 57.6% cases and 45.5% cases exhibited positive TSP-1 expression.VEGF and ANG-2 expressions were found to be associated with significant higher level of MVD (P<0.01 and P<0.05,respectively).TSP-1 expression was found to be associated with significant low level of MVD (P<0.01).Positive TSP-1 expression was also found to be associated with higher level of intrahepatic metastasis (46.7% vs 5.6%,P<0.05).CONCLUSION: Considerable angiogenesis compared to other solid tumors can be observed in CCC.VEGF and ANG-2 might play a proangiogenic role and TSP-1 may play an inhibitory role.Although TSP-1 may increase the intrahepatic metastasis of CCC,neither MVD levels nor the expression of VEGF,ANG-1,or ANG-2 is associated with tumor differentiation,invasion and metastasis. 相似文献
195.
Miyake-Jima, a round island of about 8 km in diameter, is located about 200 km south of Tokyo, Japan (34°08′ N, 139°53′ E).
In July 2000, the central cone of this island collapsed and a new eruption started with the falling of volcanic ash and SO2 emission. In October 2001, we measured the distribution of bacteria, and Frankia, a symbiotic nitrogen-fixing actinomycete that forms root nodules, and ectomycorrhizal fungi associated with alder in newly
deposited ash and its underlying soil by cultivation of Alnus sieboldiana seedlings in these soils. There were fewer bacteria growing on the nutrient broth agar and fewer bacteria growing on 100-fold
diluted nutrient broth agar in newly deposited volcanic ash than there were growing in the buried old soil. In four out of
five sites, little or no nodulation was observed in newly deposited ash; abundant root nodules were formed in the underlying
soil. Ectomycorrhizae formed in the seedlings cultivated in the underlying soil. In May 2003, the distribution of Frankia and ectomycorrhizal fungi in soil at different depths (up to 160 cm) was also investigated. Frankia and ectomycorrhizal fungi were relatively abundant in surface soil layers. 相似文献
196.
197.
To investigate morphological acclimation to differences in nutrient availability, we compared shoot and needle morphology of Picea glehnii (Friedr. Schmidt) M. T. Mast. and Picea jezoensis (Siebold & Zucc.) Carrière trees growing on nutrient-poor volcanic ash and nutrient-rich, brown forest soil. Trees of both species were shorter and had more open canopies when growing on volcanic ash than when growing on brown forest soil. Nutrient-poor conditions limited height growth less in P. glehnii than in P. jezoensis. In both species, trees growing on volcanic ash had shorter annual increments in the previous year and more needles per shoot length and, hence, a smaller shoot silhouette area (SSA) relative to needle dry mass (NDM) than trees growing on brown forest soil. Soil type had less effect on shoot projected needle area (PNA). Total needle area (TNA) of P. glehnii shoots was similar between soil types, whereas TNA of P. jezoensis was lower in trees growing on volcanic ash than in trees growing on brown forest soil. For both species, low SSA in response to nutrient-poor conditions resulted in low shoot SSA/PNA ratios, indicating high within-shoot self-shading. Shoot SSA/TNA of P. glehnii was lower in trees growing on volcanic ash than in trees growing on brown forest soil, indicating that needles were sun-acclimated. In contrast, shoot SSA/TNA of P. jezoensis was higher in trees growing on volcanic ash than in trees growing on brown forest soil. The contrasting response of TNA to low nutrient availability was associated with species-specific differences in needle morphology. Needles of P. glehnii growing on volcanic ash were slightly shorter, wider, thicker and heavier than those of trees growing on brown forest soil, indicating morphological acclimation to high irradiance. Needles of P. jezoensis growing on volcanic ash were shorter than those of trees growing on brown forest soil, but did not show morphological acclimation to high irradiance in width, thickness or mass. For both species, nutrient-poor conditions decreased maximum photosynthetic rate (Amax) per NDM. However, when expressed per PNA, the decrease in Amax was reduced, and when expressed per SSA, Amax was higher in trees growing on volcanic ash than in trees growing on brown forest soil. On volcanic ash, Amax per NDM was lower for P. glehnii than for P. jezoensis. However, morphological changes at the shoot and needle levels reversed this trend when Amax was expressed per SSA or per PNA. The species-specific differences in morphological response to differences in soil nutrient availability suggest that P. glehnii is more tolerant of nutrient-poor conditions, whereas P. jezoensis is better at exploiting nutrient-rich soils. 相似文献
198.
Eka Mulya Alamsyah Liu Chang Nan Masaaki Yamada Kinji Taki Hiroaki Yoshida 《Journal of Wood Science》2007,53(1):40-46
To estimate the potential bonding performance of bonded wood products from tropical fast-growing tree species, a study on
the bondability of Paraserianthes falcataria L. Nielsen, Pinus merkusii Jungh et. De. Vriese, and Acacia mangium Willd from Indonesia was conducted. Two-ply laminations were produced using polyvinyl acetate emulsion (PVAc), urea formaldehyde
(UF), resorcinol formaldehyde (RF), and water-based polymer isocyanate (API) adhesives. In order to determine the bonding
performance, the block-shear test was applied according to the Japanese Agricultural Standard for structural glued laminated
timber under normal conditions and after accelerated-aging treatments. To support this study, the wettability of each wood
species was also investigated through contact-angle measurement. The results showed that the bonding performance of low-density
P. falcataria was better than that of medium-density P. merkusii and medium-density A. mangium, while the bonding performance of medium-density P. merkusii was better than that of medium-density A. mangium. Furthermore, compared with A. mangium, the small contact angle and good wettability in P. falcataria and P. merkusii result in better adhesion and more intimate contact between the wood surfaces and adhesive. 相似文献
199.
Currently, many researchers argue in favor of decentralization, as it facilitates more locally based and innovative forest policy. However, many local government administrations, especially those of municipalities, lack sufficient resources to function efficiently under a decentralized regime. There is an urgent need to reassess administrative systems that can handle both decentralization and responsible administration. In this paper, resource management systems are evaluated in terms of comprehensiveness of resource management, professionalism of resource management, and public participation, by means of a comparative study of the New Zealand and Finnish systems. Finland has the advantage of nurturing and retaining experts, as a result of having specialized local organizations formed by the central government ministries. However, in Finland, it is difficult to achieve comprehensiveness and public participation, because such complex coordination is required among the vertically divided administrative organizations and between the national and local governments. In contrast, comprehensiveness and public participation are easily achieved in New Zealand because local governments are responsible for almost all resource management. However, its small-scale local governments, in particular, have serious difficulty in obtaining the services of experts. There are many lessons to learn from New Zealand about using public participation to achieve comprehensive resource management by local governments. At the same time, the effectiveness of the Finnish system, which centers on the national government, is undeniably effective in securing professionals. It is necessary to devise a combination of both systems that suits Japans situation and capitalizes on the advantages of both systems. 相似文献
200.
Kariwa H Lokugamage K Lokugamage N Miyamoto H Yoshii K Nakauchi M Yoshimatsu K Arikawa J Ivanov LI Iwasaki T Takashima I 《The Japanese journal of veterinary research》2007,54(4):145-161
Hantaviruses are causative agents of some severe human illnesses, including hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The viruses are maintained by rodent hosts, and humans acquire infection by inhaling virus-contaminated excreta from infected animals. To examine the epidemiology of hantavirus infections in Japan and Far East Russia, we conducted epidemiological surveys in these regions. In Japan, anti-hantavirus antibodies were found in four rodent species, Clethrionomys rufocanus, Rattus norvegicus, R. rattus, and Apodemus speciosus. Although no new HFRS cases have been officially reported over the past 20 years in Japan, one member of the Japan Ground Self-Defense Force did test positive for hantavirus antibody. Repeated surveys in Far East Russia have revealed that two distinct hantavirus types cause severe HFRS in this region. Hantavirus sequences identified from A. peninsulae, fetal HFRS cases in Vladivostok, and Amur virus are highly similar to each other (> 92% identity), but they are less similar (approximately 84% identity) to the prototypical Hantaan virus, which is carried by A. agrarius. Phylogenetic analysis also indicates that Amur and A. peninsulae-associated viruses are distinct from Hantaan virus, suggesting that A. peninsulae is the reservoir animal for Amur virus, which causes severe HFRS. From HFRS patients in the Khabarovsk region, we identified viruses with nucleotide sequences that are more similar to Far East virus (> 96%identity) than to the Hantaan (88-89% identity) or Amur (81-83% identity) viruses. Phylogenetic analysis also indicates that the viruses from Khabarovsk HFRS patients are closely related to the Far East virus, and distinct from Amur virus. 相似文献