G-band mode is one of the most important Raman modes of single-walled carbon nanotubes （SWCNTs）. The vibrational frequency of the mode can be used to characterize SWC- NTs. However, analytical expression that can li...G-band mode is one of the most important Raman modes of single-walled carbon nanotubes （SWCNTs）. The vibrational frequency of the mode can be used to characterize SWC- NTs. However, analytical expression that can link the frequency to the geometrical parameters of a SWCNT is to date not reported. Based on a molecular mechanics model, the analytical solution is obtained for G-band mode frequency of SWCNTs. The result calculated from the present solutions is in good agreement with the existing experimental and numerical data.展开更多
Clear G-bands were revealed by applying the TUG method on chromosomes of 5 species of higher plants (Lilium davdii, Viciafaba, Hordeum vulgare, Ginkgo biloba and Triticum monococcam). Some details of the TUG method wh...Clear G-bands were revealed by applying the TUG method on chromosomes of 5 species of higher plants (Lilium davdii, Viciafaba, Hordeum vulgare, Ginkgo biloba and Triticum monococcam). Some details of the TUG method which consisted of treating chromosomes with both trypsin and urea were also studied. The mechanisms that might account for the presence of G-bands in plants were discussed.展开更多
Well spread pachytene bivalents and high resolution G-handing patterns have been obtainedby using the prolonged hypotonic treatment combined with the trypsin-hot salt banding technique in the sper-maries of rice field...Well spread pachytene bivalents and high resolution G-handing patterns have been obtainedby using the prolonged hypotonic treatment combined with the trypsin-hot salt banding technique in the sper-maries of rice field eels(Monopterus albus Zuiew).Each bivalent has been idendified and a total of 310—450 bands on 12 bivalents observed.This might bethe largest number of multiple bands obtained from fish chromosomes so far published.An idiogram of 372G-bands has been set up and detailed descriptions of the landmark systems and the band positions have beengiven.展开更多
In the past few years, clear and abundant G-bands in more than ten plants have been successfully observed by use of animal and human G-banding procedures, which mainly include trypsin, ASG, AMD, urea, SDS, NaOH, NaHCO...In the past few years, clear and abundant G-bands in more than ten plants have been successfully observed by use of animal and human G-banding procedures, which mainly include trypsin, ASG, AMD, urea, SDS, NaOH, NaHCO<sub>3</sub> and Utakoji methods etc. However, all G-banding production methods have direct relations with the chemical factors. Although there is usually heat treatment （about 60℃） prior to the G-banding procedure in animal and human chromosomes, G-banding patterns have not yet been reported only by specif-展开更多
Preliminary genetic studies in Trechaleidae spider family show high variation in sex chromosomes and high heterocigocity,suggesting high chromatin plasticity.The trechaleids Paratrechalea ornata,Trechalea bucculenta a...Preliminary genetic studies in Trechaleidae spider family show high variation in sex chromosomes and high heterocigocity,suggesting high chromatin plasticity.The trechaleids Paratrechalea ornata,Trechalea bucculenta and Trechaleoides biocellata are present in Uruguay.Males offering nuptial gifts during courtship have been reported in P.ornata and T.bucculenta but not in T.biocellata.Nuptial gifts are an inherited trait probably highly affected by environmental factors,which play an important role in gene expression.We hypothesize that this trait could be associated with tissue-specific genes existing in G-bands.We investigate the male meiosis in these 3 species,their sex chromosome system and the effects of G-banding on their chromosomes,and elucidate genetic differences among them.Meiotic stages of the 3 species were submitted to Giemsa-staining and G-banding treatments.We observed a haploid number of n=11 in P.ornata and n=13 in both T.bucculenta and T.biocellata.Males from the 3 species presented an X_(1)X_(2)0 sex chromosome system,which is suggested as ancestral in Araneae.In P.ornata and T.bucculenta,both sex chromosomes were together and aligned in parallel until the segregation during anaphase I.In contrast to these species,sex chromosomes of T.biocellata usually remained distant from each other until diakinesis when they were observed associated in parallel disposition.Interstitial G-bands were similar in P.ornata and T.bucculenta,and they both differed from those in T.biocellata.The special behavior of sex chromosomes in T.biocellata as well as the different G-banding pattern of this species suggests the existence of novel modifications in this species.展开更多
1.27μm波段的氧分子近红外气辉是火星大气最重要的气辉辐射之一,该气辉高光谱分辨辐射传输模型的建立对于研制火星探测载荷,反演火星大气的风场温度场与臭氧浓度,以及研究火星空间物理,有重要的科学价值与工程意义.在研究火星大气O_(2)...1.27μm波段的氧分子近红外气辉是火星大气最重要的气辉辐射之一,该气辉高光谱分辨辐射传输模型的建立对于研制火星探测载荷,反演火星大气的风场温度场与臭氧浓度,以及研究火星空间物理,有重要的科学价值与工程意义.在研究火星大气O_(2)(a^(1)Δ_(g))气辉光化学反应模型的基础上,提出了O_(2)(a^(1)Δ_(g))气辉体辐射率的计算方法,并建立了火星大气气辉辐射传输理论;通过与用于研究火星大气特征的光谱学探测仪(Spectroscopy Spectrograph for the Investigation of Characteristics of the Atmosphere of Mars,SPICAM)的实测数据进行对比,验证了所建立的火星O_(2)(a^(1)Δ_(g))气辉高光谱分辨辐射传输模型的准确性;针对火星与地球大气的O_(2)(a^(1)Δ_(g))气辉,在体辐射率、自吸收效应,以及临边辐射光谱特性三个方面进行了系统深入的比较,对比结果表明,火星大气由于密度低、氧气丰度小,其自吸收效应可以忽略不计,但其O_(2)(a^(1)Δ_(g))气辉辐射强度与地球大气相当,可以用于火星大气的风场温度场与臭氧浓度的探测与反演.展开更多
目的:对1例X连锁隐性遗传鱼鳞病合并隐睾的患儿及其家系成员进行遗传学分析,探讨其致病原因。方法:对患儿及其家庭成员进行常规染色体G显带核型分析和低深度全基因组拷贝数变异测序分析(CNV-seq)。结果:染色体核型分析未见明显异常。CNV...目的:对1例X连锁隐性遗传鱼鳞病合并隐睾的患儿及其家系成员进行遗传学分析,探讨其致病原因。方法:对患儿及其家庭成员进行常规染色体G显带核型分析和低深度全基因组拷贝数变异测序分析(CNV-seq)。结果:染色体核型分析未见明显异常。CNV-seq检测发现患儿及哥哥和母亲的X染色体p22.33-p22.31处缺失5.28Mb区域,该片段包含Xp22.31 recurrent region (includes STS)全部。结论:患儿X染色体拷贝数变异遗传自其母亲,Xp22.31缺失是该患儿异常表型的遗传学病因。展开更多
基金supported by the National Natural Science Foundation of China (Nos10872120 and 10732040)Shanghai Shuguang Program (08SG39)+2 种基金Shanghai Rising Star Program (No09QH1401000)Innovation Program of Shanghai Municipal Education Commission (09ZZ97)Shanghai Leading Academic Discipline Project (S30106)
文摘G-band mode is one of the most important Raman modes of single-walled carbon nanotubes （SWCNTs）. The vibrational frequency of the mode can be used to characterize SWC- NTs. However, analytical expression that can link the frequency to the geometrical parameters of a SWCNT is to date not reported. Based on a molecular mechanics model, the analytical solution is obtained for G-band mode frequency of SWCNTs. The result calculated from the present solutions is in good agreement with the existing experimental and numerical data.
文摘Clear G-bands were revealed by applying the TUG method on chromosomes of 5 species of higher plants (Lilium davdii, Viciafaba, Hordeum vulgare, Ginkgo biloba and Triticum monococcam). Some details of the TUG method which consisted of treating chromosomes with both trypsin and urea were also studied. The mechanisms that might account for the presence of G-bands in plants were discussed.
基金the National Doctorate Research Foundation of Chinathe National Natural Science Foundation of China
文摘Well spread pachytene bivalents and high resolution G-handing patterns have been obtainedby using the prolonged hypotonic treatment combined with the trypsin-hot salt banding technique in the sper-maries of rice field eels(Monopterus albus Zuiew).Each bivalent has been idendified and a total of 310—450 bands on 12 bivalents observed.This might bethe largest number of multiple bands obtained from fish chromosomes so far published.An idiogram of 372G-bands has been set up and detailed descriptions of the landmark systems and the band positions have beengiven.
基金Project supported by the National Natural Science Foundation of China.
文摘In the past few years, clear and abundant G-bands in more than ten plants have been successfully observed by use of animal and human G-banding procedures, which mainly include trypsin, ASG, AMD, urea, SDS, NaOH, NaHCO<sub>3</sub> and Utakoji methods etc. However, all G-banding production methods have direct relations with the chemical factors. Although there is usually heat treatment （about 60℃） prior to the G-banding procedure in animal and human chromosomes, G-banding patterns have not yet been reported only by specif-
基金We thank Fernando Costa,Macarena Gonzalez,Anita Aisenberg,Soledad Ghione,Rodrigo Postiglioni and Carlos Toscano-Gadea for their help in the collection of spiders.We thank Nicolas Grasso and Wanda Iriarte for kindly helping with the techniques and software images.We also would like to thank Fernando Costa for the constructive discussions,Estefania Stanley and Ted Henderson for the English corrections and 3 anonymous referees for valuable comments on the manuscript.
文摘Preliminary genetic studies in Trechaleidae spider family show high variation in sex chromosomes and high heterocigocity,suggesting high chromatin plasticity.The trechaleids Paratrechalea ornata,Trechalea bucculenta and Trechaleoides biocellata are present in Uruguay.Males offering nuptial gifts during courtship have been reported in P.ornata and T.bucculenta but not in T.biocellata.Nuptial gifts are an inherited trait probably highly affected by environmental factors,which play an important role in gene expression.We hypothesize that this trait could be associated with tissue-specific genes existing in G-bands.We investigate the male meiosis in these 3 species,their sex chromosome system and the effects of G-banding on their chromosomes,and elucidate genetic differences among them.Meiotic stages of the 3 species were submitted to Giemsa-staining and G-banding treatments.We observed a haploid number of n=11 in P.ornata and n=13 in both T.bucculenta and T.biocellata.Males from the 3 species presented an X_(1)X_(2)0 sex chromosome system,which is suggested as ancestral in Araneae.In P.ornata and T.bucculenta,both sex chromosomes were together and aligned in parallel until the segregation during anaphase I.In contrast to these species,sex chromosomes of T.biocellata usually remained distant from each other until diakinesis when they were observed associated in parallel disposition.Interstitial G-bands were similar in P.ornata and T.bucculenta,and they both differed from those in T.biocellata.The special behavior of sex chromosomes in T.biocellata as well as the different G-banding pattern of this species suggests the existence of novel modifications in this species.
文摘1.27μm波段的氧分子近红外气辉是火星大气最重要的气辉辐射之一,该气辉高光谱分辨辐射传输模型的建立对于研制火星探测载荷,反演火星大气的风场温度场与臭氧浓度,以及研究火星空间物理,有重要的科学价值与工程意义.在研究火星大气O_(2)(a^(1)Δ_(g))气辉光化学反应模型的基础上,提出了O_(2)(a^(1)Δ_(g))气辉体辐射率的计算方法,并建立了火星大气气辉辐射传输理论;通过与用于研究火星大气特征的光谱学探测仪(Spectroscopy Spectrograph for the Investigation of Characteristics of the Atmosphere of Mars,SPICAM)的实测数据进行对比,验证了所建立的火星O_(2)(a^(1)Δ_(g))气辉高光谱分辨辐射传输模型的准确性;针对火星与地球大气的O_(2)(a^(1)Δ_(g))气辉,在体辐射率、自吸收效应,以及临边辐射光谱特性三个方面进行了系统深入的比较,对比结果表明,火星大气由于密度低、氧气丰度小,其自吸收效应可以忽略不计,但其O_(2)(a^(1)Δ_(g))气辉辐射强度与地球大气相当,可以用于火星大气的风场温度场与臭氧浓度的探测与反演.
文摘目的:对1例X连锁隐性遗传鱼鳞病合并隐睾的患儿及其家系成员进行遗传学分析,探讨其致病原因。方法:对患儿及其家庭成员进行常规染色体G显带核型分析和低深度全基因组拷贝数变异测序分析(CNV-seq)。结果:染色体核型分析未见明显异常。CNV-seq检测发现患儿及哥哥和母亲的X染色体p22.33-p22.31处缺失5.28Mb区域,该片段包含Xp22.31 recurrent region (includes STS)全部。结论:患儿X染色体拷贝数变异遗传自其母亲,Xp22.31缺失是该患儿异常表型的遗传学病因。
文摘采用外周血淋巴细胞培养及G带染色体标本制作技术,研究和分析华南虎(Panthera tigris amoyensis)染色体的核型和带型。结果表明:华南虎二倍体染色体数为2n=38条,其中常染色体18对,性染色体1对。常染色体按相对长度从长到短依次编号为1~18。根据着丝粒指数可将华南虎染色体分为4组,即A组(m),包括2、5、13、18和X;B组(Sm),包括1、4、7、8、9、10、11、12、14、17和Y;C组(St),包括3、6;D组(t),包括15、16。核型公式为8(m)+20(Sm)+4(St)+4(t),XY(m,Sm)/XX(m,m)。本研究成功制备了华南虎染色体核型标本,初步建立了华南虎染色体G带核型模式图谱。经比对,发现华南虎与东北虎(P. t. altaica)染色体核型存在明显差异,可为虎亚种的分类研究提供依据,同时能为华南虎种群基因多样性及遗传学研究提供新的参考和开辟新的途径。
