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1.
酒精┐盐酸┐醋酸洋红在植物染色体制片中的运用刘建全(中国科学院西北高原生物研究所,西宁810001)HEAPPLICATIONOFALCOHOLICHYDROCHLORICACI┐DCARMINESTAINTOTHEPLANTCHROMOSOMESS...  相似文献   

2.
中国科学院动物研究所兽类标本馆藏模式标本名录   总被引:1,自引:0,他引:1  
罗彤 《动物分类学报》1998,23(3):333-335
中国科学院动物研究所兽类标本馆藏模式标本名录CATALOGUEOFTHEMAMMALTYPESPECIMENSPRESERVEDINTHEMAMMALCOLLECTIONOFTHEINSTITUTEOFZOOLOGY,CHINESEACADEMYOF...  相似文献   

3.
人工饲养条件下子午沙鼠的繁殖特征   总被引:5,自引:0,他引:5  
蒋卫  郑强 《兽类学报》1995,15(1):75-76,72
人工饲养条件下子午沙鼠的繁殖特征THEBREEDINGFEATUREOFMERIONESMERIDIANUSUNDERTHEARTIFlCIALCONDITIONSKeywordsMerionesmeridianus;Keeping;Reproduc...  相似文献   

4.
应用蛋白dotblot技术检测了低氧内皮细胞条件培养液(HECCM)和常氧内皮细胞条件培养液(NECCM)内PDGF相对含量,并利用[3H]-TdR掺入法和流式细胞术观察了HECCM和NECCM及加入特异PDGF抗体对肺动脉平滑肌细胞(PASMC)生长的影响。结果表明,HECCM中的PDGF含量明显高于NECCM;HECCM能明显增强PASMC内DNA合成,促进PASMC从Go/G1期进入S期;当预先加入PDGF-B链抗体时,则会明显地抑制HECCM对PASMC的DNA合成,阻止PASMC从Go/G1期进入S期。结果提示,低氧时PASMC增殖与肺动脉内皮细胞分泌释放PDGF增加有关  相似文献   

5.
被子植物核型胚乳细胞化机理研究的现状   总被引:1,自引:0,他引:1  
被子植物核型胚乳细胞化机理研究的现状李师翁(庆阳师专生物系,甘肃西峰745000)ADVANCESINTHESTUDIESONTHEMECHANISMOFCELLULARIZATIONOFNUCLEARENDOSPERMINANGIOSPERMSLi...  相似文献   

6.
中国美绥螨属一新纪录种ANEWLYRECORDEDSPECIESOFAMEROSEIUSFROMChinA¥//(ACARI:AMEROSEllDAE)畏美绥螨Amemiruspovidus(C.L.Koc,1839)中国新纪录。雌螨体长283·3—...  相似文献   

7.
鲤体长与体内元素富集数学模型王继忠,徐小清(中国科学院水生生物研究所,武汉430072)AMATHEMATIXALMODELFORBODYLENGTHANDELEMENTCONTENTINTHEBODYOFCARP¥WangJizhongandXuX...  相似文献   

8.
中国果瓣螺属─新纪录(肺螺亚纲:基眼目:耳螺科)ANEWRECORDOFCARYCHIUMFROMCHINA(PULMONATA:BASOMMATOPHORA:ELLOBIIDAE)¥CHENDe-niu(InstituteofZoology,Aca...  相似文献   

9.
陈卫  付必谦 《兽类学报》1994,14(4):312-313
中华姬鼠种群生态的初步分析THEPRELIMINARYANALYSISONTHEPOPULATIONECOLOGYOFCHINESEFIELDMOUSE(APODEMUSDRACO)KeyWordsChineseFieldMouse(Apodemus...  相似文献   

10.
中国革螨二新纪录种(蜱螨亚纲:厉螨科、巨螫螨科)TWONEWLYRECORDEDSPECIESOFGAMASINAFROMCHINA(ACARI:LAELAPIDAE,MACROCHELIDAE)¥YERUI-YU(XinjiangInstitute...  相似文献   

11.
Psychophysical cross-adaptation experiments were performed with two carbohydrates, sucrose (SUC) and fructose (FRU), and two sweeteners, acesulfame-K (MOD) and dulcin (DUL). Seven subjects were asked to match concentrations that elicited the same intensity as a sucrose reference (30 g/l). Cross-adaptation levels were calculated as the ratio of isointense concentrations measured for a given stimulus before and under adaptation. On average, cross-adaptation between SUC and FRU is low and apparently reciprocal. By contrast, cross-adaptation between SUC and MOD is clearly non-reciprocal: SUC adapts MOD significantly (24%, P < 0.005), but MOD fails to adapt SUC (2%, P < 0.79). Significant and reciprocal cross-enhancement is observed between DUL and MOD (approximately -20%, P < 0.03), and also between SUC and DUL (approximately -15%, P < 0.08). In parallel, molecular modeling of the four tastants was performed in order to look for the 12 common binding motifs that were isolated on 14 other tastants in a previous study. SUC and FRU each display 10 out of the 12 binding motifs, whereas DUL and MOD only display four and five distinct motifs respectively and do not have any motif in common. Experimental cross-adaptation levels seem to correlate well with the number of motifs that molecules have in common. FRU and SUC share a majority of binding motifs and correlatively show mutual cross-adaptation. Four motifs of MOD are found among the 10 motifs of SUC, which may explain why SUC cross-adapts MOD but not vice versa. By contrast, DUL and MOD do not share any motif and do not cross- adapt. The various molecular mechanisms that may be responsible for cross-adaptation and/or cross-enhancement are discussed in light of our results.   相似文献   

12.
摘要 目的:探究氧化锆强化硅酸锂玻璃陶瓷与Lava UItimate优韧瓷嵌体修复根管治疗后大面积缺损牙的咀嚼能力和外观的效果。方法:选择298例牙缺损患者随机分为观察组和对照组2组,其中观察组患者给与Lava UItimate优韧瓷嵌体修复治疗,对照组给与氧化锆强化硅酸锂玻璃陶瓷嵌体修复治疗。对比分析两组患者修复效果、咀嚼能力、外观变化、牙龈指数和菌斑指数、修复满意度以及并发症发生率。结果:观察组患者修复的完整度为99.33 %,颜色匹配度为97.32 %,边缘适合性为98.66 %,均显著高于对照组的77.18 %、65.77 %和67.11 %(P<0.05)。修复后,观察组患者的咀嚼能力、外观变化显著优于对照组(P<0.05),PLI和GI显著低于对照组(P<0.05)。并且,观察组患者对修复的总满意度为99.33 %,显著高于对照组的82.55 %(P<0.05),并发症发生率为2.01 %,显著低于对照组的29.53 %(P<0.05)。结论:Lava UItimate优韧瓷嵌体修复根管治疗后大面积缺损牙的咀嚼能力和外观的效果较氧化锆强化硅酸锂玻璃陶瓷好,可显著降低并发症发生率,提高患者满意度,值得临床推广使用。  相似文献   

13.
Vita Blue: a new 633-nm excitable fluorescent dye for cell analysis   总被引:2,自引:0,他引:2  
L G Lee  G M Berry  C H Chen 《Cytometry》1989,10(2):151-164
Several new derivatives of fluorescein were synthesized. The dyes were characterized by NMR; and the absorbance, excitation, and emission spectra were measured. The fluorescence quantum yields of the dyes were determined. The pKa3 values of the dyes were measured by fluorescence titration. The characteristics of the fluorescein and sulfonefluorescein derivatives were compared. The most promising dye for use in cell analysis appeared to be compound 9, which was given the name Vita Blue. The dibutyrate ester of Vita Blue was made and the compound was given the name Vita Blue dibutyrate (VBDB, 14). The Km of VBDB with pig liver esterase was measured and found to be 4 x 10(-5) M. The pKa3 of Vita Blue was 7.56 +/- 0.03; both acidic and basic forms were fluorescent (dual fluorescence). The use of VBDB as an intramolecular esterase substrate and its utility for the discrimination between live and dead cells by flow cytometry is described.  相似文献   

14.
The fixation principle of threaded cups ensures high primary stability. Inadequate results with first-generation threaded cups led to modifications of surface machining. 10 threaded cups of the first generation, and 27 of the second and third generations were systematically analysed and their shapes measured using a no-touch light section technique. In addition, measurements of surface roughness were performed. Implants of the first generation made of polyethylene, ceramic or cobalt-chrome have an average surface roughness (Ra) of 1.5 microns. Approximately one-half of these implants have a conical shape, and one-third a height that is greater than the radius. Threaded cups of the second generation are made either of CP-titanium or titanium alloy. The average corundum-blasted surface roughness is 4.5 microns. Hydroxyapatite-coated (HA) implants have a surface roughness of 5.0 microns. Approximately 45% of the implants have a conical, biconical or flattened-conical shape, while one-third are of hemispherical shape. Approximately 90% of the cups have a height that is up to 23% smaller than the radius. A few cups have a height that approximates the radius. Implants of the third generation with identical surface structure can be supplied with crosslinked-polyethylene inlays or, optionally, with metal/metal or ceramic/ceramic contact surfaces. Primary stability, biocompatible materials and a structured surface are essential for ensuring osseointegration over the long-term. Corundum-blasted pure titanium or titanium alloys with corundum-blasted or HA-coated implants can be considered standard for these cups.  相似文献   

15.
Engel SA 《Neuron》2005,45(4):613-623
Primary visual cortex contains at least two distinct populations of color-selective cells: neurons in one have circularly symmetric receptive fields and respond best to reddish and greenish light, while neurons in another have oriented receptive fields and a variety of color preferences. The relative prevalence and perceptual roles of the two kinds of neurons remain controversial, however. We used fMRI and a selective adaptation technique to measure responses attributable to these two populations. The technique revealed evidence of adaptation in both populations and indicated that they each produced strong signals in V1 and other human visual areas. The activity of both sets of neurons was also reflected in color appearance measurements made with the same stimuli. Thus, both oriented and unoriented color-selective cells in V1 are important components of the neural pathways that underlie perception of color.  相似文献   

16.
The mod5-1 mutation is a nuclear mutation in Saccharomyces cerevisiae that reduces the biosynthesis of N6-(delta 2-isopentenyl)adenosine in both cytoplasmic and mitochondrial tRNAs to less than 1.5% of wild-type levels. The tRNA modification enzyme, delta 2-isopentenyl pyrophosphate:tRNA isopentenyl transferase, cannot be detected in vitro with extracts from mod5-1 cells. A characterization of the MOD5 gene would help to determine how the same enzyme activity in different cellular compartments can be abolished by a single nuclear mutation. To that end we have cloned the MOD5 gene and shown that it restores delta 2-isopentenyl pyrophosphate:tRNA isopentenyl transferase activity and N6-(delta 2-isopentenyl)adenosine to tRNA in both the mitochondria and the nucleus/cytoplasm compartments of mod5-1 yeast cells. That MOD5 sequences are expressed in Escherichia coli and can complement an N6-(delta 2-isopentenyl)-2-methylthioadenosine-deficient E. coli mutant leads us to conclude that MOD5 is the structural gene for delta 2-isopentenyl pyrophosphate:tRNA isopentenyl transferase.  相似文献   

17.
18.
发明一种组织微阵列供体取样与受体蜡块制作的新器具和新方法 . 利用这种新器具和新方法成功地制作了分别含 448 和 390 个供体组织点阵的组织微阵列受体蜡块和切片 . 这种新方法制作的组织微阵列切片经 H&E 染色,显微镜下观察证实,所有切片均无供体点阵组织脱落,切片厚度适中,组织结构无挤压变形,细胞形态均匀一致 . 免疫组化检测 P53 和 P16 蛋白在组织微阵列切片与其相应的常规组织切片中的表达结果完全一致 . 这种组织微阵列供体取样与受体蜡块制作新器具和新方法成本低廉,操作简便,具有在实验室推广应用的价值 .  相似文献   

19.
Ten Isolates of powdery mildew were tested on three spring barley cultivars known to express partial resistance and on Golden Promise. Measurements of colony lengths were made under several different environments and compared with similar data produced from several cultivars containing one of two major resistance genes. Significant isolate, cultivar and environment interactions were recorded and one isolate in particular showed adaptation to a partially resistant cultivar. Measurements of infection frequency were also made under two temperature regimes. Again significant isolate, cuitivar and temperature interactions were recorded and the same isolate showed adaptation to the same partially resistant cultivar. This indicates that adaptation to a source of partial resistance can be found amongst unselected isolates and that pleiotropically adapted genotypes may rapidly overcome such resistance in the field following its widespread deployment. Other genes for resistance were detected in the major gene cultivars, including partial resistance in the ml-v genotypes.  相似文献   

20.
The structure of the xyloglucan synthesised in vitro by the particulate fraction of suspension-cultured soybean (Glycine max) cells from UDP-glucose and UDP-xylose is mainly composed of two kinds of oligosaccharide-building blocks, a heptasaccharide unit and a pentassaccharide unit [T. Hayashi and K. Matsuda, J. Biol Chem., 256, 11117 (1981)]. The synthesis of the pentasaccharide unit is probably the first step in the construction of oligosaccharide building blocks to elongate the ²-1,4-glucan backbone. This enzymatically synthesized xyloglucan was shown to have the same molecular size (Mw, 180,000) as the xyloglucan prepared from soybean cell walls by gel filtration on a Sepharose CL-6B column, and the same building blocks distributed among each fraction. A pulse-chase experiment indicated that the pentasaccharide unit was converted into the heptasaccharide unit. The conversion was regulated by the concentration of UDP-xylose.  相似文献   

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