Objeclive The aim of this study was to investigate R-band of Cervus nippon hortulorum chromosomes and to provide references for genetic variation and gene location of Cervus nippon hortulorum. [Metbod] Cell division w...Objeclive The aim of this study was to investigate R-band of Cervus nippon hortulorum chromosomes and to provide references for genetic variation and gene location of Cervus nippon hortulorum. [Metbod] Cell division was synchronized by the pepripheral blood lymphocyte culture and the excessive dosage of thymine deoxyribonucleoside, and R-band of Cervus nippon hortulorum chromosomes was also analyzed by RBG-banding technique. Result The number of haploid chromosome banding increased to 400. The R-band of No. 1, No. 2, No. 3, No. 4, chromosome X and Y were almost just opposite to the high-resolution G band of them. The terminal of chromosomes except No. 21, No. 24 and No. 28 were all pos- itive deeply stained. E Conclusion] R-band of Cervus nippon hortulorum chromosomes can be manifested by RBG-binding technique.展开更多
The technique of simultaneous G banding and in situ hybridization has been developed in plants for the first time.Using this technique.RFLP marker umc58 closely linked with the hm1 gene dictating Helminthosporium carb...The technique of simultaneous G banding and in situ hybridization has been developed in plants for the first time.Using this technique.RFLP marker umc58 closely linked with the hm1 gene dictating Helminthosporium carbonum susceptibility1 was localized onto 1L3(chromosome 1,long arm,the third band from the centromere to the end of the arm),5L5 and 9L5.Theresults demonstrated that umc58 was a tripli cated sequence.It was deduced that umc58 probably was in a duplicated region that includes a part of Helminthosporium carbonum susceptibility genes(hm1 and hm2),as the hybridization sites of umc58 in chro mosomes 1 and 9 were those at which the genes localize.The techniques of simultaneous G banding and ISH in plants are discussed.展开更多
Aim: To assess for the first time the occurrence of Y chromosomal microdeletions and partial deletions of the Azoospermia Factor c (AZFc) region in Sri Lankan men and to correlate them with clinical parameters. Met...Aim: To assess for the first time the occurrence of Y chromosomal microdeletions and partial deletions of the Azoospermia Factor c (AZFc) region in Sri Lankan men and to correlate them with clinical parameters. Methods: In a retrospective study, we analyzed 96 infertile men (78 with non-obstructive azoospermia) and 87 controls with normal spermatogenesis. AZFa, AZFb, AZFc and partial deletions within the AZFc region were analyzed by multiplex polymerase chain reaction (PCR) according to established protocols. Results: No AZFa, AZFb or AZFc deletions were found in the control group. Seven patients in the group of infertile men were found to have deletions as following: one AZFa, two AZFc, two AZFbc and two AZFabc. The relative distribution of these patterns was significantly different compared with that found in the German population. Extension analysis confirmed that the deletions occurred according to the current pathogenic model, gr/gr deletions were found to be equally present both in the patients (n = 4) and in the control group (n = 4). One b2/b3 deletion was found in the patient group. Conclusion: These results suggest that the frequency and pattern of microdeletions of the Y chromosome in Sri Lankan men are similar to those found in other populations and confirm that gr/gr deletions are not sufficient to cause spermatogenetic failure. (Asian J Androl 2006 Jan; 8: 39-44)展开更多
随着网络业务流量的增长,通信业务对密集波分复用(DWDM)的性能要求越来越高。为了提高传输效率,传输频谱逐渐向C+L Band传输扩展,Super C Band传输应运而生,但目前与之对应的掺铒光纤放大器(EDFA)相关研究较少。针对这一问题,文章提出...随着网络业务流量的增长,通信业务对密集波分复用(DWDM)的性能要求越来越高。为了提高传输效率,传输频谱逐渐向C+L Band传输扩展,Super C Band传输应运而生,但目前与之对应的掺铒光纤放大器(EDFA)相关研究较少。针对这一问题,文章提出了一种针对Super C Band传输的EDFA结构,基于Giles模型,分析了EDFA在Super C Band的特性,利用多级泵浦机制,设计了一种可以在Super C Band范围内进行放大的EDFA。结果表明,在-9.3 dBm入光时,该EDFA可以实现26 dB的平坦增益,16.7 dBm的输出功率,此时噪声指数小于5 dB,Ripple小于0.1 dB。并且根据需要,在入光处于-15.0~-3.5 dBm范围内时,通过调节泵浦功率与可调衰减器,均能够实现7~26 dB的可调增益。该EDFA可应用于5G传输和数据中心之间光纤通信等场合。展开更多
The human C17orf25 gene (Accession No. AF177342) is one of thirteen genes cloned from a region displaying a high score of loss of heterozygosity within chromosome 17pl3.3 in human hepatocellular carcinoma in China[l]....The human C17orf25 gene (Accession No. AF177342) is one of thirteen genes cloned from a region displaying a high score of loss of heterozygosity within chromosome 17pl3.3 in human hepatocellular carcinoma in China[l]. To unveil the underlying mechanisms for the transcription regulation of this gene and understand its implication to the hepatocellular carcinogenesis, we looked into the relevant aspects by both bioinformatic and experimental executions. We found: 1, The abundant expression of the C17orf25 gene was evident in all the cell lines and tissue samples tested, showing little hepatoma-selectivity; 2, Its transcription starts at a single site, locating at -60 from the translation initiation codon; 3, A 58 bp fragment containing the transcription start, extending from -112 to -55, represents the minimal promoter; 4, The consensus sequence within this fragment recognized by SP1 contributes predominantly to the activity of the minimal promoter; 5, The bioinformatic analysis suggests that the C17orf25 gene may encode a protein in the family of the glyoxalase. Our data has provided some deep insight into both function and regulation of the C1 7orf25 gene in the context of the normal liver and hepatocellular carcinoma.展开更多
Haynaldia villosa (2n=2X= 14, VV), a relative of wheat, plays important roles in wheat improvement mainly owing to its disease resistance. Powdery mildew resistance gene Pm21 has been successfully transferred into w...Haynaldia villosa (2n=2X= 14, VV), a relative of wheat, plays important roles in wheat improvement mainly owing to its disease resistance. Powdery mildew resistance gene Pm21 has been successfully transferred into wheat by Cytogenetic Institute, Nanjing Agricultural University, China, and is widely used in the current wheat breeding programs. In this research, our objective is to further transfer and utilize the beneficial genes such as eye-spot resistance, yellow rust resistance, and gene of the tufted bristles on the glume ridge (a remarkable morphology) mapped on 2V of Haynaldia villosa. A disomic addition line with gametocidal chromosome 3C ofAegilops triuncialis added in Norin-26 was crossed to the wheat-H, villosa disomic substitution 2V(2D) and the hybrid F1 was then self-crossed. Chromosome C-banding, genomic in situ hybridization (GISH), and meiotic analysis in combination with molecular markers were applied to detect the chromosome variations derived from hybrids Fz and F3. To date, four translocations including one small segmental translocation T6BS·6BL-2VS, two whole arm translocations (preliminarily designed as T3DS·2VL and T2VS.7DL) and one intercalary translocation T2VS·2VL-W-2VL, one deletion Del. 2VS·2VL-, one monotelosomic Mt2VS, and one isochromosome 2VS·2VS line have been developed and characterized. One wheat SSR marker Xwmc25.120 tagging 2VS and one wheat STS marker NAU/STSBCD135-1 (2BL) tagging 2VL were successfully used to confirm the alien chromosome segments involved in the seven lines. The tufted bristles on the glume ridge appeared in lines T2VS-7DL, Mt2VS, 2VS-2VS as well as the parent DS2V(2D), whereas in T3DS·2VL, this trait did not appear. The gene controlling the tufted bristles was located on 2VS. Gametocidal chromosome 3C ofAegilops triuncialis could successfully induce chromosome 2V structural changes.展开更多
This paper describes the design and preliminary test of the low-level radio frequency(LLRF)part of the C band high-gradient test facility for the Shanghai Soft X-ray Free-Electron Laser(SXFEL)-Linear Accelerator(LINAC...This paper describes the design and preliminary test of the low-level radio frequency(LLRF)part of the C band high-gradient test facility for the Shanghai Soft X-ray Free-Electron Laser(SXFEL)-Linear Accelerator(LINAC).Before installation,the accelerating structures should be tested and conditioned.During the conditioning process,breakdown detection is needed to protect the accelerating structures and klystron from damage.The PCI extensions for instrumentation-based LLRF system and auto-conditioning algorithm are designed and applied in the LLRF part of the C band high-gradient test facility.Three C band accelerating structures and 1 pulse compressor have completed conditioning and were installed in the SXFEL-LINAC.展开更多
Using a combination of hybridization of PAC to a cDNA library and RACE technique, we isolated a novel cDNA, designated as C17orf25 (Chromosome 17 open rea(ling frame 25, previously named it HC71A), from the deletion r...Using a combination of hybridization of PAC to a cDNA library and RACE technique, we isolated a novel cDNA, designated as C17orf25 (Chromosome 17 open rea(ling frame 25, previously named it HC71A), from the deletion region on chromosome 17p13.3. The cDNA encodes a protein of 313 amino acids with a calculated molecular mass of 34.8 kDa. C17orf25 is divided into 10 exons and 9 introns, spanning 23 kb of genomic DNA. Northern blot analysis showed that the mRNA expression of C17orf25 was decreased in hepatocellular carcinoma samples as compared to adjacent noncancerous liver tissues from the same patients. The transfection of C17or25 into the hepatocellular carcinoma cell SMMC7721 and overexpression could inhibit the cell growth. The above results indicate that C17orf25 is a novel human gene, and the cloning and preliminary characterization of C17orf25 is a prerequisite for further functional analysis of this novel gene in human hepatocellular carcinoma.展开更多
A mobile C-band dual polarimetric weather radar J type (PCDJ), which adopts simultaneous transmission and simultaneous reception (STSR) of horizontally and vertically polarized signals, was first developed in Chin...A mobile C-band dual polarimetric weather radar J type (PCDJ), which adopts simultaneous transmission and simultaneous reception (STSR) of horizontally and vertically polarized signals, was first developed in China in 2008. It was deployed in the radar observation plan in the South China Heavy Rainfall Experiment (SCHeREX) in the summer of 2008 and 2009, as well as in Tropical Western Pacific Ocean Observation Experiments and Research on the Predictability of High Impact Weather Events from 2008 to 2010 in China (TWPOR). Using the observation data collected in these experiments, the radar systematic error and its sources were analyzed in depth. Meanwhile an algorithm that can smooth differential propagation phase (~Dp) for estimating the high-resolution specific differential phase (KDP) was developed. After attenuation correction of reflectivity in horizontal polarization (ZH) and differential reflectivity (ZDR) of PCDJ radar by means of KDP, the data quality was improved significantly. Using quality-controlled radar data, quantitative rainfall estimation was performed, and the resutls were compared with rain-gauge measurements. A synthetic ZH /KDp-based method was analyzed. The results the traditional ZH-based method when the rain suggest that the synthetic method has the advantage over rate is 〉5 mm h^-1. The more intensive the rain rates, the higher accuracy of the estimation.展开更多
Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C ...Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C (MMC). Methods Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro. Results The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 lag/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC (P〈0.0001). Conclusion Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.展开更多
A C-band RF pulse compressor is in development at SINAP It comprises of two resonant cavities,two mode convertors and a 3 dB power divider.TE_(0.1.15)mode is selected for obtaining higher quality factor Q_0 of the RF ...A C-band RF pulse compressor is in development at SINAP It comprises of two resonant cavities,two mode convertors and a 3 dB power divider.TE_(0.1.15)mode is selected for obtaining higher quality factor Q_0 of the RF pulse compressor cavities,so that the power gain factor can be 3.2,which is supposed to multiply the RF power from 50 MW to 1 60 MW.In this paper,we report our work on C-band RF pulse compressor,namely the design simulation and cold test results.展开更多
The physical design and cooling test of a C-band 2MeV standing wave (SW) accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section ...The physical design and cooling test of a C-band 2MeV standing wave (SW) accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm, excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30% capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM (full width at half maximum of density distribution) is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3:9:10.展开更多
In order to transfer useful genes of Hordeum californicum into common wheat (Triticum aestivum L.), the T. aestivum c.v. Chinese Spring (CS)-H. californicum amphiploid was crossed to CS, and its backcrossing and s...In order to transfer useful genes of Hordeum californicum into common wheat (Triticum aestivum L.), the T. aestivum c.v. Chinese Spring (CS)-H. californicum amphiploid was crossed to CS, and its backcrossing and self-fertilized progenies were analyzed by morpho- logical observation, cytological, biochemical and molecular marker techniques. Alien addition lines with two H. californicum chromo- somes were identified and their genetic constitution was characterized. STS-PCR analysis using chromosome 2B specific markers indi- cated that chromosome H3 of H. californicum belongs to homoeologous group 2, and was thus designated 2H. SDS-PAGE showed that chromosome H2 of H. californicum belongs to homoeologous group 5, and was designated 5H. The CS-H. californicum amphiploid and the chromosome addition lines (DA2H and MA5H) identified were evaluated for powdery mildew (Erysiphe graminis f. sp. triticii) resis- tance in field. The preliminary results indicated that the amphiploid showed higher powdery mildew resistance than CS. However, chro- mosome addition lines DA2H and MA5H were highly susceptible to powdery mildew, indicating that major powdery mildew resistant genes of H. californicum should be located on chromosomes other than 2H and 5H.展开更多
The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by Intern...The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by International Telecommunication Union. The X-band is used for terrestrial broadband communication, radar applications, and portions of the X-band are assigned for deep space telecommunications. In this paper, a design of 4 × 1 Ultra Wide Band (UWB) antenna array for C-band and X-band applications is introduced. Metamaterial sixteen-unit cells are incorporated into each antenna element for radiation characteristics enhancement purposes. Permeability and permittivity of metamaterial unit cells are obtained all over the operating bandwidth. UWB unequal power divider is used to feed the proposed four elements antenna array based on Chebyshev excitation method. The proposed antenna has a suitable 3 dB beam width and gains all over the operating bandwidth which extends from 5.6 GHz to 10.9 GHz. The proposed antenna covers 60% and 72.5% of the C-band and X-band, respectively. The proposed antenna is fabricated, measured, and good agreement is obtained between simulated and measured results. The obtained performance ensures the suitability of the proposed antenna array for C-band and X-band applications.展开更多
Aim: To evaluate the genetic instability of 11 fertile and 25 infertile men. Methods: The methodology of sister chromatid exchanges (SCEs) was applied to cultures of peripheral blood lymphocytes, and the levels of...Aim: To evaluate the genetic instability of 11 fertile and 25 infertile men. Methods: The methodology of sister chromatid exchanges (SCEs) was applied to cultures of peripheral blood lymphocytes, and the levels of SCEss were analyzed as a quantitative index of genotoxicity, along with the values of the mitotic index (MI) and the proliferation rate index (PRI) as qualitative indices of cytotoxicity and cytostaticity, respectively. The genotoxic and antineoplastic agent, mitomycin C (MMC), and caffeine (CAF) - both well-known inhibitors of DNA repair mechanism - were used in an attempt to induce chromosomal instability in infertile men, so as to more easily detect the probable underlying damage on DNA. Results: Our experiments illustrated that infertile men, compared with fertile ones, demonstrated a statistically significant DNA instability in peripheral blood lymphocytes after being exposed simultaneously to MMC and CAF. Conclusion: The current study showed vividly that there was genetic instability in infertile men which probably contributes to the development of an impaired reproductive capacity. (Asian JAndro12006 Mar; 8: 199-204)展开更多
The authors present a photoluminescence and UV (ultraviolet)-optical absorbance study on single walled carbon nanotubes CNTs (carbon nanotubes) and TiO2 mixtures. The authors observed variation of△ф = 0.6 eV in ...The authors present a photoluminescence and UV (ultraviolet)-optical absorbance study on single walled carbon nanotubes CNTs (carbon nanotubes) and TiO2 mixtures. The authors observed variation of△ф = 0.6 eV in optical gap for micrometric anatase and 0.1 eV for nanometric rutile or anatase at a concentration of CNTs of about 1.5 weight %. The large difference in △ф is attributed to differences in dimensions of dioxide grains and in morphology of CNTs/Ti02 composites. Photoluminescence emission is drastically reduced and absorption in the UV range is increased at low CNT concentration for both anatase and rutile phases.展开更多
基金supported by Chongqing Normal University Fund (XLY012)Natural Science Foundation of Chongqing Science and Technology Commission (CSTC 2006BB1260)
文摘Objeclive The aim of this study was to investigate R-band of Cervus nippon hortulorum chromosomes and to provide references for genetic variation and gene location of Cervus nippon hortulorum. [Metbod] Cell division was synchronized by the pepripheral blood lymphocyte culture and the excessive dosage of thymine deoxyribonucleoside, and R-band of Cervus nippon hortulorum chromosomes was also analyzed by RBG-banding technique. Result The number of haploid chromosome banding increased to 400. The R-band of No. 1, No. 2, No. 3, No. 4, chromosome X and Y were almost just opposite to the high-resolution G band of them. The terminal of chromosomes except No. 21, No. 24 and No. 28 were all pos- itive deeply stained. E Conclusion] R-band of Cervus nippon hortulorum chromosomes can be manifested by RBG-binding technique.
文摘The technique of simultaneous G banding and in situ hybridization has been developed in plants for the first time.Using this technique.RFLP marker umc58 closely linked with the hm1 gene dictating Helminthosporium carbonum susceptibility1 was localized onto 1L3(chromosome 1,long arm,the third band from the centromere to the end of the arm),5L5 and 9L5.Theresults demonstrated that umc58 was a tripli cated sequence.It was deduced that umc58 probably was in a duplicated region that includes a part of Helminthosporium carbonum susceptibility genes(hm1 and hm2),as the hybridization sites of umc58 in chro mosomes 1 and 9 were those at which the genes localize.The techniques of simultaneous G banding and ISH in plants are discussed.
文摘Aim: To assess for the first time the occurrence of Y chromosomal microdeletions and partial deletions of the Azoospermia Factor c (AZFc) region in Sri Lankan men and to correlate them with clinical parameters. Methods: In a retrospective study, we analyzed 96 infertile men (78 with non-obstructive azoospermia) and 87 controls with normal spermatogenesis. AZFa, AZFb, AZFc and partial deletions within the AZFc region were analyzed by multiplex polymerase chain reaction (PCR) according to established protocols. Results: No AZFa, AZFb or AZFc deletions were found in the control group. Seven patients in the group of infertile men were found to have deletions as following: one AZFa, two AZFc, two AZFbc and two AZFabc. The relative distribution of these patterns was significantly different compared with that found in the German population. Extension analysis confirmed that the deletions occurred according to the current pathogenic model, gr/gr deletions were found to be equally present both in the patients (n = 4) and in the control group (n = 4). One b2/b3 deletion was found in the patient group. Conclusion: These results suggest that the frequency and pattern of microdeletions of the Y chromosome in Sri Lankan men are similar to those found in other populations and confirm that gr/gr deletions are not sufficient to cause spermatogenetic failure. (Asian J Androl 2006 Jan; 8: 39-44)
文摘随着网络业务流量的增长,通信业务对密集波分复用(DWDM)的性能要求越来越高。为了提高传输效率,传输频谱逐渐向C+L Band传输扩展,Super C Band传输应运而生,但目前与之对应的掺铒光纤放大器(EDFA)相关研究较少。针对这一问题,文章提出了一种针对Super C Band传输的EDFA结构,基于Giles模型,分析了EDFA在Super C Band的特性,利用多级泵浦机制,设计了一种可以在Super C Band范围内进行放大的EDFA。结果表明,在-9.3 dBm入光时,该EDFA可以实现26 dB的平坦增益,16.7 dBm的输出功率,此时噪声指数小于5 dB,Ripple小于0.1 dB。并且根据需要,在入光处于-15.0~-3.5 dBm范围内时,通过调节泵浦功率与可调衰减器,均能够实现7~26 dB的可调增益。该EDFA可应用于5G传输和数据中心之间光纤通信等场合。
文摘The human C17orf25 gene (Accession No. AF177342) is one of thirteen genes cloned from a region displaying a high score of loss of heterozygosity within chromosome 17pl3.3 in human hepatocellular carcinoma in China[l]. To unveil the underlying mechanisms for the transcription regulation of this gene and understand its implication to the hepatocellular carcinogenesis, we looked into the relevant aspects by both bioinformatic and experimental executions. We found: 1, The abundant expression of the C17orf25 gene was evident in all the cell lines and tissue samples tested, showing little hepatoma-selectivity; 2, Its transcription starts at a single site, locating at -60 from the translation initiation codon; 3, A 58 bp fragment containing the transcription start, extending from -112 to -55, represents the minimal promoter; 4, The consensus sequence within this fragment recognized by SP1 contributes predominantly to the activity of the minimal promoter; 5, The bioinformatic analysis suggests that the C17orf25 gene may encode a protein in the family of the glyoxalase. Our data has provided some deep insight into both function and regulation of the C1 7orf25 gene in the context of the normal liver and hepatocellular carcinoma.
基金the National Natural Science Foundation of China (30270827).
文摘Haynaldia villosa (2n=2X= 14, VV), a relative of wheat, plays important roles in wheat improvement mainly owing to its disease resistance. Powdery mildew resistance gene Pm21 has been successfully transferred into wheat by Cytogenetic Institute, Nanjing Agricultural University, China, and is widely used in the current wheat breeding programs. In this research, our objective is to further transfer and utilize the beneficial genes such as eye-spot resistance, yellow rust resistance, and gene of the tufted bristles on the glume ridge (a remarkable morphology) mapped on 2V of Haynaldia villosa. A disomic addition line with gametocidal chromosome 3C ofAegilops triuncialis added in Norin-26 was crossed to the wheat-H, villosa disomic substitution 2V(2D) and the hybrid F1 was then self-crossed. Chromosome C-banding, genomic in situ hybridization (GISH), and meiotic analysis in combination with molecular markers were applied to detect the chromosome variations derived from hybrids Fz and F3. To date, four translocations including one small segmental translocation T6BS·6BL-2VS, two whole arm translocations (preliminarily designed as T3DS·2VL and T2VS.7DL) and one intercalary translocation T2VS·2VL-W-2VL, one deletion Del. 2VS·2VL-, one monotelosomic Mt2VS, and one isochromosome 2VS·2VS line have been developed and characterized. One wheat SSR marker Xwmc25.120 tagging 2VS and one wheat STS marker NAU/STSBCD135-1 (2BL) tagging 2VL were successfully used to confirm the alien chromosome segments involved in the seven lines. The tufted bristles on the glume ridge appeared in lines T2VS-7DL, Mt2VS, 2VS-2VS as well as the parent DS2V(2D), whereas in T3DS·2VL, this trait did not appear. The gene controlling the tufted bristles was located on 2VS. Gametocidal chromosome 3C ofAegilops triuncialis could successfully induce chromosome 2V structural changes.
基金This work was supported by the National Key R&D Program of China(No.2018YFF0109203).
文摘This paper describes the design and preliminary test of the low-level radio frequency(LLRF)part of the C band high-gradient test facility for the Shanghai Soft X-ray Free-Electron Laser(SXFEL)-Linear Accelerator(LINAC).Before installation,the accelerating structures should be tested and conditioned.During the conditioning process,breakdown detection is needed to protect the accelerating structures and klystron from damage.The PCI extensions for instrumentation-based LLRF system and auto-conditioning algorithm are designed and applied in the LLRF part of the C band high-gradient test facility.Three C band accelerating structures and 1 pulse compressor have completed conditioning and were installed in the SXFEL-LINAC.
基金the National 863High Technology Research and Development Pro-gram of China (Zl9-02--0l-0l) to Wan DF and theProject of Ch
文摘Using a combination of hybridization of PAC to a cDNA library and RACE technique, we isolated a novel cDNA, designated as C17orf25 (Chromosome 17 open rea(ling frame 25, previously named it HC71A), from the deletion region on chromosome 17p13.3. The cDNA encodes a protein of 313 amino acids with a calculated molecular mass of 34.8 kDa. C17orf25 is divided into 10 exons and 9 introns, spanning 23 kb of genomic DNA. Northern blot analysis showed that the mRNA expression of C17orf25 was decreased in hepatocellular carcinoma samples as compared to adjacent noncancerous liver tissues from the same patients. The transfection of C17or25 into the hepatocellular carcinoma cell SMMC7721 and overexpression could inhibit the cell growth. The above results indicate that C17orf25 is a novel human gene, and the cloning and preliminary characterization of C17orf25 is a prerequisite for further functional analysis of this novel gene in human hepatocellular carcinoma.
基金funded by National Natural Science Foundation of China (Grant Nos. 40975013 and 40975014)Chinese Academy of Meteorological Sciences (CAMS) basic scientific and operational project:Observation and retrieval methods of microphysics and dynamic parameters of cloud and precipitation with multi-wavelength Remote Sensing,SCHeREX and TWPOR
文摘A mobile C-band dual polarimetric weather radar J type (PCDJ), which adopts simultaneous transmission and simultaneous reception (STSR) of horizontally and vertically polarized signals, was first developed in China in 2008. It was deployed in the radar observation plan in the South China Heavy Rainfall Experiment (SCHeREX) in the summer of 2008 and 2009, as well as in Tropical Western Pacific Ocean Observation Experiments and Research on the Predictability of High Impact Weather Events from 2008 to 2010 in China (TWPOR). Using the observation data collected in these experiments, the radar systematic error and its sources were analyzed in depth. Meanwhile an algorithm that can smooth differential propagation phase (~Dp) for estimating the high-resolution specific differential phase (KDP) was developed. After attenuation correction of reflectivity in horizontal polarization (ZH) and differential reflectivity (ZDR) of PCDJ radar by means of KDP, the data quality was improved significantly. Using quality-controlled radar data, quantitative rainfall estimation was performed, and the resutls were compared with rain-gauge measurements. A synthetic ZH /KDp-based method was analyzed. The results the traditional ZH-based method when the rain suggest that the synthetic method has the advantage over rate is 〉5 mm h^-1. The more intensive the rain rates, the higher accuracy of the estimation.
基金supported by a grant from the Scientific and Technical Research Council of Turkey, Ankara (TüBiTAK, 107T279 (TBAG/HD-304).
文摘Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C (MMC). Methods Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro. Results The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 lag/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC (P〈0.0001). Conclusion Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.
基金the Accelerator Laboratory of Tsinghua University for experiment supports
文摘A C-band RF pulse compressor is in development at SINAP It comprises of two resonant cavities,two mode convertors and a 3 dB power divider.TE_(0.1.15)mode is selected for obtaining higher quality factor Q_0 of the RF pulse compressor cavities,so that the power gain factor can be 3.2,which is supposed to multiply the RF power from 50 MW to 1 60 MW.In this paper,we report our work on C-band RF pulse compressor,namely the design simulation and cold test results.
文摘The physical design and cooling test of a C-band 2MeV standing wave (SW) accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm, excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30% capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM (full width at half maximum of density distribution) is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3:9:10.
文摘In order to transfer useful genes of Hordeum californicum into common wheat (Triticum aestivum L.), the T. aestivum c.v. Chinese Spring (CS)-H. californicum amphiploid was crossed to CS, and its backcrossing and self-fertilized progenies were analyzed by morpho- logical observation, cytological, biochemical and molecular marker techniques. Alien addition lines with two H. californicum chromo- somes were identified and their genetic constitution was characterized. STS-PCR analysis using chromosome 2B specific markers indi- cated that chromosome H3 of H. californicum belongs to homoeologous group 2, and was thus designated 2H. SDS-PAGE showed that chromosome H2 of H. californicum belongs to homoeologous group 5, and was designated 5H. The CS-H. californicum amphiploid and the chromosome addition lines (DA2H and MA5H) identified were evaluated for powdery mildew (Erysiphe graminis f. sp. triticii) resis- tance in field. The preliminary results indicated that the amphiploid showed higher powdery mildew resistance than CS. However, chro- mosome addition lines DA2H and MA5H were highly susceptible to powdery mildew, indicating that major powdery mildew resistant genes of H. californicum should be located on chromosomes other than 2H and 5H.
文摘The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by International Telecommunication Union. The X-band is used for terrestrial broadband communication, radar applications, and portions of the X-band are assigned for deep space telecommunications. In this paper, a design of 4 × 1 Ultra Wide Band (UWB) antenna array for C-band and X-band applications is introduced. Metamaterial sixteen-unit cells are incorporated into each antenna element for radiation characteristics enhancement purposes. Permeability and permittivity of metamaterial unit cells are obtained all over the operating bandwidth. UWB unequal power divider is used to feed the proposed four elements antenna array based on Chebyshev excitation method. The proposed antenna has a suitable 3 dB beam width and gains all over the operating bandwidth which extends from 5.6 GHz to 10.9 GHz. The proposed antenna covers 60% and 72.5% of the C-band and X-band, respectively. The proposed antenna is fabricated, measured, and good agreement is obtained between simulated and measured results. The obtained performance ensures the suitability of the proposed antenna array for C-band and X-band applications.
文摘Aim: To evaluate the genetic instability of 11 fertile and 25 infertile men. Methods: The methodology of sister chromatid exchanges (SCEs) was applied to cultures of peripheral blood lymphocytes, and the levels of SCEss were analyzed as a quantitative index of genotoxicity, along with the values of the mitotic index (MI) and the proliferation rate index (PRI) as qualitative indices of cytotoxicity and cytostaticity, respectively. The genotoxic and antineoplastic agent, mitomycin C (MMC), and caffeine (CAF) - both well-known inhibitors of DNA repair mechanism - were used in an attempt to induce chromosomal instability in infertile men, so as to more easily detect the probable underlying damage on DNA. Results: Our experiments illustrated that infertile men, compared with fertile ones, demonstrated a statistically significant DNA instability in peripheral blood lymphocytes after being exposed simultaneously to MMC and CAF. Conclusion: The current study showed vividly that there was genetic instability in infertile men which probably contributes to the development of an impaired reproductive capacity. (Asian JAndro12006 Mar; 8: 199-204)
文摘The authors present a photoluminescence and UV (ultraviolet)-optical absorbance study on single walled carbon nanotubes CNTs (carbon nanotubes) and TiO2 mixtures. The authors observed variation of△ф = 0.6 eV in optical gap for micrometric anatase and 0.1 eV for nanometric rutile or anatase at a concentration of CNTs of about 1.5 weight %. The large difference in △ф is attributed to differences in dimensions of dioxide grains and in morphology of CNTs/Ti02 composites. Photoluminescence emission is drastically reduced and absorption in the UV range is increased at low CNT concentration for both anatase and rutile phases.