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| 1 | Detection and parameter estimation of multicomponent LFM signal based on the fractional Fourier transform显示文摘This paper presents a new method for the detection and parameter estimation of multicomponent LFM signals based on the fractional Fourier transform. For the optimization in the fractional Fourier domain, an algorithm based on Quasi-Newton method is proposed which consists of two steps of searching, leading to a reduction in computation without loss of accuracy. And for multicomponent signals, we further propose a signal separation technique in the fractional Fourier domain which can effectively suppress the interferences on the detection of the weak components brought by the stronger components. The statistical analysis of the estimate errors is also performed which perfects the method theoretically, and finally, simulation results are provided to show the validity of our method. | QI Lin1, 2, TAO Ran1, ZHOU Siyong1 & WANG Yue1 1. Department of Electronic Engineering, Beijing Institute of Technology, Beijing 100081, China 2. School of Information Engineering, Zhengzhou University, Zhengzhou 450052, China Correspondence should be addressed to QI Lin (email: qilin@bit.edu.cn) | 2004 | Science in China(Series F)2004，47，2： | 143 |
| 2 | Quantitative relationships between vegetation and several pollen taxa in surface soil from North China显示文摘According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept | LI Yiyin, ZHANG Xinshi & ZHOU Guangsheng1. Department of Urbon and Environmental Sciences, Peking University, Beijing 100871, China 2. Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 3. School of Urban and Environmental Sciences, Northeast Normal University, Changchun 130024, China Correspondence should be addressed to Li Yiyin | 2000 | Chinese Science Bulletin2000，45，16： | 24 |
| 3 | On the new results of global attractive set and positive invariant set of the Lorenz chaotic system and the applications to chaos control and synchronization显示文摘Constructing a family of generalized Lyapunov functions, a new method is proposed to obtain new global attractive set and positive invariant set of the Lorenz chaotic system. The method we proposed greatly simplifies the complex proofs of the two famous estimations presented by the Russian scholar Leonov. Our uniform formula can derive a series of the new estimations. Employing the idea of intersection in set theory, we extract a new Leonov formula-like estimation from the family of the estimations. With our method and the new estimation, one can confirm that there are no equilibrium, periodic solutions, almost periodic motions, wandering motions or other chaotic attractors outside the global attractive set. The Lorenz butterfly-like singular attractors are located in the global attractive set only. This result is applied to the chaos control and chaos synchronization. Some feedback control laws are obtained to guarantee that all the trajectories of the Lorenz systems track a periodic solution, or globally stabilize an unstable (or locally stable but not globally asymptotically stable) equilibrium. Further, some new global exponential chaos synchronization results are presented. Our new method and the new results are expected to be applied in real secure communication systems. | LIAO Xiaoxin 1, 2, 3 , FU Yuli 4 & XIE Shengli 4 1. Department of Control Science & Control Engineering, Huazhong University of Science & Technology, Wuhan 430074, China 2. School of Automation, Wuhan University of Science & Technology, Wuhan 430070, China 3. School of Information, Central South University of Economy, Politics and Law, Wuhan 430064, China 4. School of Electronics & Information Engineering, South China University of Technology, Guangzhou 510640, China Correspondence should be addressed to Liao Xiaoxin (email: xiaoxin_liao@hotmail.com) | 2005 | Science in China(Series F)2005，48，3： | 23 |
| 4 | Ultramafic xenoliths in Mesozoic diorite in west Shandong Province显示文摘Ultramafic xenoliths are common in Tietonggou intrusion, Laiwu, Shandong Prov-ince. Peridotite xenoliths develop two-stage metasomatism popularly: (i) The early metasoma-tism is characterized by intergranular clinopyroxene and phlogopite; (ii) The later metasomatism is characterized by orthopyroxene veins with a few plagioclases and amphiboles. These ul-tramafic xenoliths are thought to be mostly from the crust-mantle transitional zone on the basis of their combination, mineral chemistry, equilibrium temperature, and metasomatic characteristics. Major elements, rare earth elements, and Sr-Nd isotopic composition of the ultramafic xenoliths indicate that there is a petrogenetic relationship between the silica-enriched xenoliths and their host diorites. We propose that such silica enrichment might be an indicator of melt-rock interac-tions in the Mesozoic lithosphere beneath western Shandong. | CHEN Lihui1,2 & ZHOU Xinhua2 1.The Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,China and School of Earth and Space Sciences,Peking University,Beijing 100871,China 2.Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China Correspondence should be addressed to Chen Lihui(email: lihui_chen@263.net) | 2004 | Science China Earth Sciences2004，47，6： | 19 |
| 5 | Sorafenib inhibits growth and metastasis of hepatocellular carcinoma by blocking STAT3显示文摘AIM: To investigate the inhibitory role and the underlying mechanisms of sorafenib on signal transducer and activator of transcription 3 (STAT3) activity in hepatocellular carcinoma (HCC).METHODS: Human and rat HCC cell lines were treated with sorafenib. Proliferation and STAT3 dephosphorylation were assessed. Potential molecular mechanisms of STAT3 pathway inhibition by sorafenib were evaluated. In vivo antitumor action and STAT3 inhibition were investigated in an immunocompetent orthotopic rat HCC model.RESULTS: Sorafenib decreased STAT3 phosphorylationat the tyrosine and serine residues (Y705 and S727), but did not affect Janus kinase 2 (JAK2) and phosphatase shatterproof 2 (SHP2), which is associated with growth inhibition in HCC cells. Dephosphorylation of S727 was associated with attenuated extracellular signal-regulated kinase (ERK) phosphorylation, similar to the effects of a mitogen-activated protein kinase (MEK) inhibitor U0126, suggesting that sorafenib induced S727 dephosphorylation by inhibiting MEK/ERK signaling. Meanwhile, sorafenib could also inhibit Akt phosphorylation, and both the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 and Akt knockdown resulted in Y705 dephosphorylation, indicating that Y705 dephosphorylation by sorafenib was mediated by inhibiting the PI3K/Akt pathway. Finally, in the rat HCC model, sorafenib signifi cantly inhibited STAT3 activity, reducing tumor growth and metastasis.CONCLUSION: Sorafenib inhibits growth and metastasis of HCC in part by blocking the MEK/ERK/STAT3 and PI3K/Akt/STAT3 signaling pathways, but independent of JAK2 and SHP2 activation. | Fang-Ming Gu, Quan-Lin Li, Qiang Gao, Jia-Hao Jiang, Xiao-Yong Huang, Jin-Feng Pan, Jia Fan, Jian ZhouFang-Ming Gu, Quan-Lin Li, Qiang Gao, Jia-Hao Jiang, Xiao-Yong Huang, Jin-Feng Pan, Jia Fan, Jian Zhou, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Shanghai 200032, China Author contributions: Gu FM, Li QL and Gao Q contributed equally to this work Gu FM and Li QL performed the experi- ments and interpretation of the data and statistical analysis Zhou J and Gao Q contributed to the conception and design of the study Gu FM, Gao Q, Li QL and Zhou J wrote the manuscript Jiang JH, Huang XY, Pan JF and Fan J made substantial contri- bution to the design and conception of the study and interpreta- tion of data all authors read and approved the f inal manuscript. | 2011 | World Journal of Gastroenterology2011，17，34： | 18 |
| 6 | Peat molecular fossils recording paleoclimatic change and organism replacement显示文摘The occurrence of the dominant C23 n-alkane derived from bryophyte was demonstrated to be related to the cold climate, based on the GC and GC/MS analyses on a 40-cm long peat core, in which this compound exponentially varies in abundance with the depth corresponding to the well-known second Little Ice Age. Both the variation of the chemical components of modern bryophyte resulted from climatic change and the ecological data about the biological growth influenced by climate shed light on the point that the variation of this compound in the peat was related to the cold climate. This was also evidenced by the previously-reported lacustrine data. In addition, the variations of the ratios of ketones/esters and C24 n-alkene/n-alkane (C24:1/024:0) display the trend identical with that of organisms, implicating the replacement between bryophyte and monocotyledon occurring in the peat core. | XIE Shucheng & R. P. Evershed1. Faculty of Earth Science, China University of Geosciences, Wuhan 430074, China 2. School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK Correspondence should be addressed to Xie Shucheng (e-mail: scxie@ public.wh.hb.cn) | 2001 | Chinese Science Bulletin2001，46，20： | 16 |
| 7 | Quantitative reconstruction of the paleosalinity at Qinghai Lake in the past 900 years显示文摘Based on the function relationship between the shell length of Limnocythere inopinata and the salinity of its living water in Tibetan Plateau lakes, the paleosalinty of Qinghai Lake in the past 900 years was reconstructed through the measurement of the adult body length of Limno-cythere inopinata. Meanwhile, the paleosalinity sequence of Qinghai Lake during the same period was rebuilt by the Sr/Ca ratio of the shell of Eucypris inflata combined with the Sr/Ca ratio of living ostracod valves from the species of ge-nus Eucypris inflata and the host water. The paleosalinity results obtained by two different methods were compared and assessed in this paper. To check the result, it was also contrasted with other historical climatic sequences of this area including tree ring and ice core. It was shown that the paleosalinity sequence rebuilt by adult ostracod body length had high reliability, and the paleosalinity reconstruction method by trace elements of ostracod shells was not suitable for Qinghai Lake. From the reconstructed paleosalinty se-quence of Qinghai Lake, it can be found that low salinity during 1160—1290 AD showed the humid climate condition on the Mediaeval Warm Period in this area, while the high salinity during 1410—1540 AD, 1610—1670 AD and 1770—1850 AD which was corresponding to the three cold pulses of the Little Ice Age with a dry climate condition. And the high salinity in the latest several decades was consistent with re-cent warm and dry trends of the climate in this area. The good consistency of the reconstructed palaeosalinity sequence and the precipitation sequence in this area rebuilt by tree ring proves the reconstruction of past lake salinity is reliable. | ZHANG Enlou1,2,SHEN Ji1,WANG Sumin1,YIN Yu1,ZHU Yuxin1 & XIA Weilan1 1.Key Laboratory of Lake Sediment and Environment,Nanjing institute of Geography and Limnology,Chinese Academy of Sciences,Nan-jing 210008,China 2.Graduate School of Chinese Academy of Sciences,Beijing 100039,China Correspondence should be addressed to Zhang Enlou(e-mail:elzhang@ niglas.ac.cn) | 2004 | Chinese Science Bulletin2004，49，7： | 14 |
| 8 | Artificial coordinating field and its application to motion planning of robots in uncertain dynamic environments显示文摘Artificial coordinating fields (ACF) are proposed to deal with the motion planning problems of mobile robots in uncertain dynamic environments. An ACF around an obstacle can generate two orthogonal force vectors to a robot: one is called the coordinating force vector which is purposively designed in this paper, and the other is the repulsive force vector which is the same as that in a conventional artificial potential field. The ACF is designed according to the updated motion purpose and the relative states of the robot with respect to its local environment, and it also satisfies the robots dynamic constraints. The direction of the coordinating force can be determined on line according to an optimal evaluation function. The ACF can effectively remove the local minima, and reduce the oscillation of the planned trajectory between multiple obstacles. Only local knowledge of the environments is needed in the ACF-based motion planning. The properties of the ACF such as controllability, adaptability, safety and reachability are studied and discussed in detail in this paper. Theoretical analysis and simulations are given to illustrate our main results. | JING Xingjian1, 2, WANG Yuechao1 & TAN Dalong1 1. Robotics Laboratory, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China 2. Graduate School, Chinese Academy of Sciences, Beijing 100039, China Correspondence should be addressed to Jing Xingjian | 2004 | Science China(Technological Sciences)2004，47，5： | 11 |
| 9 | The 3-D non-axisymmetrical Lamb's problem in transversely isotropic saturated poroelastic media显示文摘Based on Biots theory on fluid-saturated porous media, the displacement functions are adopted to convert the 3-D Biots wave equations in the cylindrical coordinate for transversely isotropic saturated poroelastic media into two棗one 6-order and one 2-order棗uncoupling differential governing equations. Then, the differential equations are solved by the Fourier expanding and Hankel integral transform method. Integral solutions of soil skeleton displacements and pore pressure as well as the total stresses for poroelastic media are obtained. Furthermore, the systematic study on Lambs problems for the transversely isotropic saturated poroelastic media is performed. Integral solutions for surface radial, vertical and circumferential displacements are obtained in both cases of drained surface and undrained surface under the vertical and horizontal harmonic excitation force. In the end of this paper, the numerical examples are presented. The calculation results indicate that the difference between the model of isotropic saturated poroelastic media and that of transversely isotropic saturated poroelastic media is obvious. | HUANG Yi1 & WANG Xiaogang1,2 1. School of Civil Engineering, Xian University of Architecture & Technology, Xian 710055, China 2. Department of Civil Engineering, Qinghai University, Xining 810016, China Correspondence should be addressed to Huang Yi (email: huangyih@pub.xaonline.com) Received April 15, 2004 revised July 12, 2004 | 2004 | Science China(Technological Sciences)2004，47，5： | 10 |
| 10 | Geochemical research on C-O and Sr-Nd isotopes of mantle-derived rocks from Shandong Province, China显示文摘This paper presents systematic studies on the C-O and Sr-Nd isotopic compositions for Cretaceous Badou carbonatites, Fangcheng basalts, and Jiaodong lamprophyres and Paleozoic Mengyin kimberlites in Shandong Province, China. Paleozoic kimberlites have normal and uniform C-O isotopic compositions with δ13C and δ18O in the range of -4.8‰--7.6‰ and +9.9‰-+13.2‰, respectively. However, Cretaceous three different types of mantle-derived rocks have quite different C-O isotopic compositions, indicating that the mantle sources are probably partially contaminated with organic carbon-bearing crustal materials. These Cretaceous rocks show uniform and EMII-like Sr-Nd isotopic compositions and also indicate that the mantle sources were affected by recycled crustal materials. Comparative studies of C-O and Sr-Nd isotopes reveal that the lithospheric mantle beneath the eastern North China Craton had different isotope characteristics in the Paleozoic, the early Cretaceous, and the Tertiary time. This demonstrates that the lithospheric mantle beneath the region underwent at least twice reconstructions since the Paleozoic. Available data imply that the first reconstruction mainly happened during the Triassic-Jurassic time with gradual changes and the second in the Cretaceous with abrupt changes. Results also show that the early Cretaceous (especially at 120-130 Ma) was perhaps the key period leading to the dramatic change of the Mesozoic geodynamics on the eastern North China Craton. | LIU Jianming, ZHANG Hongfu, SUN Jinggui & YE Jie1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. School of Earth Science, Jilin University, Changchun 130061, China Correspondence should be addressed to Liu Jianming (email: jmliu@mail.igcas.ac.cn) | 2004 | Science China Earth Sciences2004，47，2： | 9 |
| 11 | Induction of nicotine in tobacco by herbivory and its relation to glucose oxidase activity in the labial gland of three noctuid caterpillars显示文摘Tobacco Nicotiana tabacum L. is a host plant of Helicoverpa armigera (Hübner), Helicoverpa assulta Guenée and Spodoptera litura (Fabricius) (Lepidoptera, Noctuidae). The difference in leaf nicotine response to the feeding by these three larvae and the mechanical simulation of their feeding was examined by HPLC. Results indicated that nico- tine induction was suppressed by H. armigera and H. assulta larvae feeding or by simulated damage treated with their labial glands extracts. The production of nicotine was also suppressed by the glucose oxidase from Aspergillus niger when it was treated on mechanically wounded leaf area. On the contrary, the nicotine production was stimulated by S. litura larva feeding or by simulated damage treated with its labial gland extract. Heat denature can not counteract the stimulation effect of the S. litura labial gland extracts to to- bacco nicotine production. The glucose oxidase activity was detected in labial gland extracts of both H. armigera and H. assulta, but the activity in H. armigera was significantly higher than that in H. assulta. No glucose oxidase activity was detected in labial gland extracts of S. litura. It is shown that the glucose oxidase activity in labial glands of caterpil- lars plays an important role in the nicotine response to her- bivory. The glucose oxidase was mainly contained in the la- bial gland of H. armigera larva, and had the highest activity at pH 7.0. D-Glucose was the optimal substrate of the glucose oxidase. Labial gland glucose oxidase activities varied daily during larval development with high activities found when larvae were actively feeding. | ZONG Na1,2 & WANG Chenzhu1 1.State Key Laboratory of Integrated Management of Insects & Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100080,China 2.Graduate School of Chinese Academy of Sciences,Beijing 100080,China Correspondence should be addressed to Wang Chenzhu(e-mail: czwang@ioz.ac.cn) | 2004 | Chinese Science Bulletin2004，49，15： | 7 |
| 12 | A Model of Dynamic Recrystallization in Alloys during High Strain Plastic Deformation显示文摘Recrystallized grains, less than 200 nm in diameter were observed in heavily shear zones of a high strength low alloy steel and a Ni-based alloy, and Also grain refinement, less than 3 μm in diameter was made in high purity aluminum by ECAE at ambient temperature. The experimental results showed that high strain rate and large deformation could induce dynamic recrystallization.Based on dislocation dynamics and grain orientation change enhanced by plastic deformation,a model for the recrystallization process is developed. The model is used to explain the ultra fine grains which are formed at a temperature still much lower than that for the conventional | Qiang LI and Yongbo XU(State Key Laboratory for Fatigue and Fracture of Materials, Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110015, China) To whom correspondence should be addressed Present address: Analysis Cener, School of Mater | 1999 | Journal of Materials Science & Technology1999，15，5： | 7 |
| 13 | Population information extraction in Chaohu watershed based on RS and GIS显示文摘It is always difficult to extract population in-formation of small watershed during the region environment assessment. The report adopted compound areal interpola-tion to study the population in Chaohu watershed with the GIS technique and landuse interpretation data from remote sensing. The result indicated that the method is effective to extract population information of small watershed. | LIU Jianjun1,2 & LI Chunlai3 1. Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Graduate School, Chinese Academy of Sciences, Beijing 100039, China 3. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China Correspondence should be addressed to Liu Jianjun (e-mail: dhsliujj@ hotmail.com) | 2003 | Chinese Science Bulletin2003，48，2： | 6 |
| 14 | Correlation of glycosyltransferases mRNA expression in extrahepatic bile duct carcinoma with clinical pathological characteristics显示文摘BACKGROUND: The incidence of extrahepatic bile duct carcinoma (EBDC) has been increasing, especially in aged people, but the glycobiology of the tumor is not elucida- ted. In this study we investigated the expressions of three glycosyltransferases in 35 patients with EBDC and 35 pa- tients with benign biliary duct disease (BBDD) as well as their clinicopathological significance. METHOD: The patients were divided into several sub- groups by tumor differentiation, TNM stage, and invasion by the standards recommended by UICC. Tumor samples were immediately frozen in liquid nitrogen after resection, followed by mRNA determination of enzymes in the tissue using a mRNA selective reverse trancriptase-polymerase chain reaction kit. The mRNA levels of different groups were semi-quantitatively compared. RESULTS: The mRNA levels of N-acetylglucosaminyltrans- ferase V (GnT-V) and a subtype of α2,3 sialyltransferases for N-glycans, ST3Gal- were elevated 7.75 and 5.39 times in EBDC as compared with BBDD, respectively, and they were correlated to several clinicopathological factors including tumor advancement, differentiation, metastasis, and invasiveness. The mRNA expression of another sialyl- transferase, ST6Gal- , was also 0.63-fold higher in EBDC than in BBDD, but not involved in the clinicopathological characteristics. CONCLUSION: The elevated expression of these three gly- cosyltransferases can be considered as an important molecu- lar event in the occurrence and progression of EBDC. | Xiao-Ling Jin, Shu-Sen Zheng, Bing-Sheng Wang and Hui-Li Chen Nanjing, China Department of General Surgery, Nanjing First Hospi- tal Affiliated to Nanjing Medical University, Nanjing 210006, China Department of Hepatobiliary Surgery, First Affiliated Hospital, Zhe- jiang University School of Medicine, Hangzhou 310003, China Department of General Surgery, Zhongshan Hospital, Fudan Universi- ty, Shanghai 200032 , China and Key Laboratory of Glycocon- jugate Research, Ministry of Health, Department of Biochemistry, Fudan University School of Medicine, Shanghai 200032, China | 2004 | Hepatobiliary & Pancreatic Diseases International2004，3，2： | 6 |
| 15 | 关于老市区屋顶绿化的初步设想显示文摘本文认为屋顶绿化是老市区绿化工作的重要出路,并提出屋顶绿化的基本原则。 | StudentReporters of Environmental Protection, Middle SchoolAttached to the Guangzhou Normal University(Tutors: He Weijiang, Qi Donghai) | 1998 | 广州师院学报(社会科学版)1998，19，1： | 6 |
| 16 | Germline mutation analysis of hPMS2 gene in Chinese families with hereditary nonpolyposis colorectal cancer显示文摘AIM: To study the germline mutation of hPMS2 gene in 26 unrelated Chinese hereditary nonpolyposis colorectal cancer (HNPCC) probands and to fulfill the screening strategy for HNPCC in Chinese. METHODS: Genomic DNA was extracted from the peripheral blood. To avoid the interference of pseudogene in detection of the remaining 11 exons (exon 1-5, 9, 11-15), long-range polymerase chain reaction (PCR) was conducted to amplify the complete coding region of hPMS2 gene firstly. Then 1/8 of the PCR productswere used as template to amplify the individual exon respectively and DNA sequencing was done. Direct DNA sequencing of the conventional PCR products of exon 6, 7, 8 and 10 of hPMS2 gene was performed. The same analysis was made in 130 healthy persons without family histories of HNPCC to further investigate the pathological effects of the detected missense mutation. RESULTS: One HNPCC proband fulf illed Bethesda guidelines and was found to carry the germline mutation of hPMS2 gene, which has not been reported in Chinese HNPCC families. It was a missense mutation at c.1532C>T of exon 11. It was detected in three controls as well with an occurrence rate of 2.3% (3/130). Since it could not be found in the PMS2-single nucleotide polymorphism (SNP) database, this missense mutation is a new SNP unreported up to date. Meanwhile, 260 reported SNPs of hPMS2 gene were detected in the 26 HNPCC probands. The 2nd and 5th exons were probably the hot SNP regions of hPMS2 gene in Chinese HNPCC families involving 53.1% of all reported SNP. CONCLUSION: The germline mutation of hPMS2 gene may be rare in Chinese HNPCC families. The 2nd and 5th exons are hot SNP regions of hPMS2 gene. | Xia Sheng, Xiao-Yan Zhou, Xiang Du, Tai-Ming Zhang, WeiQi Sheng, Da-Ren Shi, Department of Pathology, Shanghai Cancer Center, Fudan University, Shanghai 200032, China Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China Heng-Hua Zhou, Department of Pathology, Shanghai Ninth People’s Hospital Affi liated to Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China San-Jun Cai, Department of Abdominal Surgery, Cancer Center, Fudan University, Shanghai 200032, China | 2010 | World Journal of Gastroenterology2010，16，30： | 6 |
| 17 | High Expression of NKG2A/CD94 and Low Expression of Granzyme B Are Associated with Reduced Cord Blood NK Cell Activity显示文摘Human umbilical cord blood (CB) has recently been used as a source of stem cells in transplantation. NK cells derived from CB are the key effector cells involved in graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL). It was reported that the activity of CB NK cells was lower than that of adult peripheral blood (PB) NK cells. In this study,we analyzed the expression of some NK cell receptors and cytotoxicity-related molecules in CB and PB NK cells. The expressions of activating NK receptors,CD16,NKG2D and NKp46,did not show significant difference between CB and PB NK cells. But the expression of inhibitory receptor NKG2A/CD94 was significantly higher on CB NK cells. As to the effector function molecules,granzyme B was expressed significantly lower in CB NK cells,but the expressions of intracellular perforin,IFN-γ,TNF-α and cell surface FasL and TRAIL did not show difference between CB and PB NK cells. The results indicated that the high expression of NKG2A/CD94 and low expression of granzyme B may be related with the reduced activity of CB NK cells. | Yanyan Wang1,2,Han Xu1,2,Xiaodong Zheng1,Haiming Wei1,Rui Sun1 and Zhigang Tian1,31Institute of Immunology,Hefei National Laboratory for Physical Materials at Microscale and School of Life Sciences,University of Science and Technology of China,Hefei 230027,China 2Yanyan Wang and Han Xu equally contributed to the present study | 2007 | Cellular & Molecular Immunology2007，4，5： | 5 |
| 18 | Synthesis of vertically aligned carbon nanotube arrays on silicon substrates显示文摘The growth of well-aligned carbon nanotube (CNT) arrays using a heat chemical vapor deposition system on silicon substrates is reported. The growth properties of CNT arrays are studied as a function of synthesis conditions. It is found that 750℃ and 10 nm Fe film are suitable conditions for the growth of well-aligned CNT arrays. CNT arrays with a uniform diameter, thick tube wall and firm cohesion to the Si substrate can be grown for C2H2 concentration of 27%. Based on the experiment, the processes of improving the alignment of CNT arrays and cohesion between CNT arrays and Si substrates are discussed. | ZHENG Ruiting1, CHENG Guoan1, PENG Yibin1, 2, ZHAO Yong1, 3, LIU Huaping1 & LIANG Changlin1 1. Key Laboratory of Radiation Beam Technology and Materials Modification of Ministry of Education, Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875, China 2. School of Science, Civil Aviation University of China, Tianjin 300300, China 3. Department of Physics, Nanchang University, Nanchang 330047, China Correspondence should be addressed to Zheng Ruiting | 2004 | Science China(Technological Sciences)2004，47，5： | 4 |
| 19 | Split liver transplantation: a reliable approach to expand donor pool显示文摘Orthotopic liver transplantation as a successful treatment of end-stage liver disease is hampered by a persistent lack of cadaveric organs. Split liver transplantation, which was first successfully performed by Medical School of Hannover in 1988, has become a mature surgical technique to expand the donor pool. Between 1993 and 1999, split liver transplantation activities have increased in Europe from 1. 2% to 10. 4% in all performed liver transplantations. Current data have strongly supported that the survival rate of patients after split liver transplantation is not significantly different from that of patients after whole-size orthotopic liver transplantation. The most important step of donor graft selection is surgeon’ s observation judged by the experience of individual transplant center. The paper aims to provide the guideline of donor selection, hepatic graft splitting, and recipient management as well. DATA SOURCES: Medical School of Hannover has accumulated plentiful experience of split liver transplantation for more than 10 cases ever since 1998. Besides that, we also reviewed a variety of literatures from other famous European and American centers specialized in this field for many years. RESULTS:According to our experience combined with the view points of others, the donor should meet the following criteria as well: (1) age less than 50 years; (2) hemodynamics stable; (3) ICU less than 5 days; (4) Na less than 170 mmol/L or better if less than 150 mmol/L. In 1996 and 1997, the Hamburg group and the UCLA group separately introduced a breakthrough technique performing split liver transplantation in situ. Evidently, the in situ technique has been limited by prolonged time of donor organ procurement , coordination with other organ procurement teams, and even extra burden on donor hospital. Some groups, therefore, have restored the ex situ or bench splitting technique , and fortunately the transplant outcomes of the ex situ technique are equivalent to those of the in situ one. Recently some new techniques have been introduced to split the liver for two adult patients, including the split-cava technique. CONCLUSIONS:It is clear that the most important factor for determining the prognosis of the patient is the time of receiving liver transplantation, not the type of liver transplantation. We still need to pay close attention to the graft to recipient weight ratio (GRWR) and the UNOS classification or MELD score before the patient is subjected to split liver transplantation. | Ji-Qi Yan, Thomas Becker, Cheng-Hong Peng, Hong-Wei Li and Juergen Klempnauer Department of Surgery, Ruijin Hospital Affiliated to Shanghai Second Medical University, Shanghai 200025, China ( Yan JQ, Peng CH and Li HW) Department of Abdominal and Transplant Surgery, Medical School of Hannover, Carl-Neuberg-Str. 1 , 30625 Hannover, Germany | 2005 | Hepatobiliary & Pancreatic Diseases International2005，4，3： | 3 |
| 20 | Origin and evolution of new exons in the rodent zinc fingerprotein 39 gene显示文摘The origin of new structures and functions is an important process in evolution. In the past decades, we have obtained some preliminary knowledge of the origin and evo- lution of new genes. However, as the basic unit of genes, the origin and evolution of exons remain unclear. Because young exons retain the footprints of origination, they can be good materials for studying origin and evolution of new exons. In this paper, we report two young exons in a zinc finger protein gene of rodents. Since they are unique sequences in mouse and rat genome and no homologous sequences were found in the orthologous genes of human and pig, the young exons might originate after the divergence of primates and rodents through exonization of intronic sequences. Strong positive selection was detected in the new exons between mouse and rat, suggesting that these exons have undergone significant functional divergence after the separation of the two species. On the other hand, population genetics data of mouse dem- onstrate that the new exons have been subject to functional constraint, indicating an important function of the new exons in mouse. Functional analyses suggest that these new exons encode a nuclear localization signal peptide, which may me- diate new ways of nuclear protein transport. To our knowl- edge, this is the first example of the origin and evolution of young exons. | PENG Lixin1,2*, ZHENG Hongkun3*, LI Xin1,2, YANG Shuang2,4, CHEN Hong1,5 & WANG Wen2 1. College of Animal Science and Technology, Northwest Sci-Tech Uni- versity of Agriculture and Forestry, Yangling 712100, China 2. CAS-Max Planck Junior Scientist Group, Key Laboratory of Cellular and Molecular Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China 3. Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 101300, China 4. Graduate School of the Chinese Academy of Sciences, Beijing 100039 China 5. Institute of Cellular and Molecular Biology, Xuzhou Normal Univer- sity, Xuzhou 221116, China Correspondence should be addressed to Wang Wen (email: wwang@ mail.kiz.ac.cn) | 2005 | Chinese Science Bulletin2005，50，11： | 3 |
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