Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indica...Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indicating that an intense folding and uplifting event took place. During the Triassic, this orogenic belt was strongly eroded, and basins were further developed. Starting from the Jurassic, a within-plate regional extension occurred, forming a series of Jurassic-Paleogene extensional basins in the peneplaned Tianshan region. Since the Neogene, a collision event between the Indian and the Eurasian plates that took place on the southern side of the Tianshan belt has caused a strong intra-continental orogeny, which is characterized by thrusting and folding. Extremely thick coarse conglomerate and sandy conglomerate of the Xiyu Formation of Neogene System were accumulated unconformably on the Tianshan piedmont. Studies have revealed that the strong compression caused by the Indian-Eurasian collision had a profound influence over the orogenic belt in the hinterland, and MesozoiC-Cenozoic brittle deformed structures superposed on the ductile deformed Paleozoic rocks. The Mesozoic extensional basins were converted into Cenozoic compressional basins. The deformation in the basins is featured by step thrusts and fault-related folds. Statistics of joints show that the principal compressive stress since the Neogene is in a N-S direction. Meanwhile, owing to the underthrusting of the basin toward the orogenic belt, the Paleozoic strata were thrust on the Meso-Cenozoic rocks as tectonic slices, revealing distinct kinematic features in different geologic units. The basin-range coupling zones are characterized by intensive compression, folding and thrusting, accompanied by local sub-E-W-trending strike-slip faults. In the Tianshan region, Cenozoic thrusting is the most common basin-range coupling mode. The folding and faulting of Mesozoic sedimentary rocks, spontaneous combustion of Jurassic coal layers and formation of sintered rocks, the Cenozoic earthquakes and active faulting, and the unique mosaic pattern of basin-range framework of Xinjiang are all products of tectonism since the Neogene.展开更多
The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are a...The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.展开更多
Based on the theory of fuzzy logic, the method of obfuscating coefficient and reliability to fuse the information of hand geometry and palm prints for identity discrimination is proposed. The experiment proves that th...Based on the theory of fuzzy logic, the method of obfuscating coefficient and reliability to fuse the information of hand geometry and palm prints for identity discrimination is proposed. The experiment proves that the method is useful and effective. Its identification rate is up to 90%, which is 20%-30% higher than that of using hand geometry or palm prints singly,thus it can be widely used in highly demanded security field, such as finance, entrance guard, etc.展开更多
The crystal structure of ([CuL(H_2O)_2](ClO_4)_2·2H_2O, CuL)(L=N-(5-sulfosalicylidene)-4′-bromoaniline) was determined by means of X-ray crystallography. The interaction between CuL and salmon sperm DNA in a 0.1...The crystal structure of ([CuL(H_2O)_2](ClO_4)_2·2H_2O, CuL)(L=N-(5-sulfosalicylidene)-4′-bromoaniline) was determined by means of X-ray crystallography. The interaction between CuL and salmon sperm DNA in a 0.1 mol/L HOAc-NaOAc buffer solution(pH 5.10) was investigated by cyclic voltammetry and UV-Vis spectroscopy. A couple of redox peaks of CuL in the cyclic voltammograms(CV) can be seen at the glassy carbon electrode. It was found that the peak current of CuL decreased significantly with a negative shift of the peak potential in the presence of DNA compared with that in the absence of DNA. In addition, the decreased absorbance of CuL was observed with increasing the concentration of DNA; the absorption spectrum of an ethidium bromide(EB)-DNA system in the presence of CuL confirms that the binding mode of CuL to DNA is different from the intercalation of EB with DNA. All the experimental results indicate that CuL can bind to DNA by electrostatic binding and form a 1∶1 association complex with a binding constant of 2.72×10 4 L/mol.展开更多
Objective: To study the value of multiple MR imaging techniques in the diagnosis of pancreatic carcinoma and the assessment of resectbility of the lesion. Methods: MR imaging was performed in 18 pa-tients with surgica...Objective: To study the value of multiple MR imaging techniques in the diagnosis of pancreatic carcinoma and the assessment of resectbility of the lesion. Methods: MR imaging was performed in 18 pa-tients with surgically and/or pathologically proven pancreatic carcinoma. GRE T1WI, TSE T2WI, GRE T1WI with fat suppression, delayed enhancement GRE T1WI, MRCP and 3D DCE MRA were used in MR scanning. Tumor involvement of the celiac trunk and its main branches, superior mesenteric artery,the portal, splenic and superior mesenteric veins were prospectively graded on a 0-4 scale based on cir-cumferential contiguity of tumor to vessel. Results: On GRE T1WI and TSE T2WI all the lesions showed slightly hypointense and hyperintense, respectively; On GRE T1WI with fat suppression, all the tumors obviously appeared hypointense; On delayed enhancement GRE T1WI, the lesions displayed irregularly circular enhancement in 14 patients and well-distributed enhancement in 4 patients. MRCP showed exten-sive bile and main pancreatic duct dilatation with typical "double-duct" sign in 8 patients. On 3D DCE MRA, we thought it was unresectable with more than half circumferential involvement of tumor to vessel,so that the portal, splenic and superior mesenteric veins were involved with 56% (10/18), 39% (7/18)and 67% (12/18), respectively. The celiac trunk and its main branches and superior mesenteric arteries were involved with 22% (4/18) and 17% (3/18), respectively. The pancreatic lesions in 2 cases could be completely resected in the evaluation of MR imaging, which was fitted to the findings of operation by pan-creatoduodenectomy. The pancreatic lesions in other 2 cases were partly, resected because there was tumor extension to superior mesenteric vein and/or artery. The tumors in the remaining 14 patients were too large and involved peripancreatic vessels or there were stomach or liver metastases, so these patients were only treated by choledochojejunostomy and gastrojejunstomy. Conclusion: The "all-in-one" MR approach including fast scanning sequences, fat suppression, MRCP and 3D DCE MRA provides the surgeon with diagnosis and assessment of resectability of tlm lesion prior to surgery of pancreatic carcinoma.展开更多
2020年我国伏季休渔期间中国毛虾限额捕捞试点在黄海海州湾实施,2021年该限额捕捞项目继续实施,在此背景下探究夏季海州湾中国毛虾资源分布对其限额捕捞精细化管理至关重要。首先基于2021年海州湾中国毛虾限额捕捞期间北斗渔船监控系统(...2020年我国伏季休渔期间中国毛虾限额捕捞试点在黄海海州湾实施,2021年该限额捕捞项目继续实施,在此背景下探究夏季海州湾中国毛虾资源分布对其限额捕捞精细化管理至关重要。首先基于2021年海州湾中国毛虾限额捕捞期间北斗渔船监控系统(Vessel monitoring system,VMS)数据提取得到各毛虾张网渔船所有捕捞网位点及其捕捞努力量,然后运用具有噪声的密度聚类(Density-based spatial clustering of application with noise,DBSCAN)算法进一步识别含有捕捞产量的网位点,从而探究夏季海州湾中国毛虾资源分布格局。结果显示,含有产量的网位点识别率为97.18%,表明DBSCAN算法能精准识别含有产量的捕捞网位点。含有产量的网位点共有898个,空间上呈聚集性分布。依据捕捞努力量情况探究得到中国毛虾资源主要分布在120°00′E~120°15′E,34°43′N~34°48′N和119°47′E~119°53′E,34°36′N~34°43′N。本研究思路可作为其他渔业捕捞活动中运用VMS数据提取含产量捕捞网位点的科学参考。展开更多
Comparative genome analysis is performed between Shigella flexneri 2a strain 301 and its close relatives, the nonpathogenic E. Coli K-12 strain MG1655. Result shows that there are 136 DNA segments whose size is larger...Comparative genome analysis is performed between Shigella flexneri 2a strain 301 and its close relatives, the nonpathogenic E. Coli K-12 strain MG1655. Result shows that there are 136 DNA segments whose size is larger than 1000 bp absent from Shigella flexneri 2a strain 301, which is up to 717253 bp in total length. These deleted segments altogether contain 670 open reading frames (ORFs). Prediction of these ORFs indicates that there are 40% genes of unknown function. The other genes of definite functions encode metabolic enzymes, structure proteins, transcription regulatory factors and some elements correlated with horizontal transfer. Here we compare the complete genomic sequences of the two closely related species, which differ in pathogenic phenotype. To our knowledge, this not only reveals the difference of genomic sequence between the two important enteric pathogens for the first time, but also provides valuable clues to further researches in its process of physiological activity, pathogenesis and the evolution of enteric bacteria.展开更多
Background Velvet antler polypeptides (VAPs), which are derived from the antler velvets, have been reported to maintain survival and promote growth and differentiation of neural cells and, especially the development ...Background Velvet antler polypeptides (VAPs), which are derived from the antler velvets, have been reported to maintain survival and promote growth and differentiation of neural cells and, especially the development of neural tissues This study was designed to explore the influence of VAPs on neural stem cells in vitro derived from embryonic rat brain Methods Neural stem cells derived from E12 14 rat brain were isolated, cultured, and expanded for 7 days until neural stem cell aggregations and neurospheres were generated The neurospheres were cultured under the condition of different concentration of VAPs followed by immunocytochemistry to detect the differentiation of neural stem cells Results VAPs could remarkablely promote differentiation of neural stem cells and most neural stem cells were induced to differentiate towards the direction of neurons under certain concentration of VAPs Conclusion Neural stem cells can be successfully induced into neurons by VAPs in vitro , which could provide a basis for regeneration of the nervous system展开更多
In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds...In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds number fluid flow applications, a subgrid turbulence model for LBM was introduced based on standard Smagorinsky subgrid model and Lattice Bhatnagar-Gross-Krook (LBGK) model. The subgrid LBGK model was subsequently used to simulate the two-dimensional driven cavity flow at high Reynolds numbers. The simulation results including distribution of stream lines, dimensionless velocities distribution, values of stream function, as well as location of vertex center, were compared with benchmark solutions, with satisfactory agreements.展开更多
基金supports from the National 973 Project on western China No.2001CB409804the key project of National Natural Science Foundation of China No.49832040.
文摘Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indicating that an intense folding and uplifting event took place. During the Triassic, this orogenic belt was strongly eroded, and basins were further developed. Starting from the Jurassic, a within-plate regional extension occurred, forming a series of Jurassic-Paleogene extensional basins in the peneplaned Tianshan region. Since the Neogene, a collision event between the Indian and the Eurasian plates that took place on the southern side of the Tianshan belt has caused a strong intra-continental orogeny, which is characterized by thrusting and folding. Extremely thick coarse conglomerate and sandy conglomerate of the Xiyu Formation of Neogene System were accumulated unconformably on the Tianshan piedmont. Studies have revealed that the strong compression caused by the Indian-Eurasian collision had a profound influence over the orogenic belt in the hinterland, and MesozoiC-Cenozoic brittle deformed structures superposed on the ductile deformed Paleozoic rocks. The Mesozoic extensional basins were converted into Cenozoic compressional basins. The deformation in the basins is featured by step thrusts and fault-related folds. Statistics of joints show that the principal compressive stress since the Neogene is in a N-S direction. Meanwhile, owing to the underthrusting of the basin toward the orogenic belt, the Paleozoic strata were thrust on the Meso-Cenozoic rocks as tectonic slices, revealing distinct kinematic features in different geologic units. The basin-range coupling zones are characterized by intensive compression, folding and thrusting, accompanied by local sub-E-W-trending strike-slip faults. In the Tianshan region, Cenozoic thrusting is the most common basin-range coupling mode. The folding and faulting of Mesozoic sedimentary rocks, spontaneous combustion of Jurassic coal layers and formation of sintered rocks, the Cenozoic earthquakes and active faulting, and the unique mosaic pattern of basin-range framework of Xinjiang are all products of tectonism since the Neogene.
文摘The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.
文摘Based on the theory of fuzzy logic, the method of obfuscating coefficient and reliability to fuse the information of hand geometry and palm prints for identity discrimination is proposed. The experiment proves that the method is useful and effective. Its identification rate is up to 90%, which is 20%-30% higher than that of using hand geometry or palm prints singly,thus it can be widely used in highly demanded security field, such as finance, entrance guard, etc.
文摘The crystal structure of ([CuL(H_2O)_2](ClO_4)_2·2H_2O, CuL)(L=N-(5-sulfosalicylidene)-4′-bromoaniline) was determined by means of X-ray crystallography. The interaction between CuL and salmon sperm DNA in a 0.1 mol/L HOAc-NaOAc buffer solution(pH 5.10) was investigated by cyclic voltammetry and UV-Vis spectroscopy. A couple of redox peaks of CuL in the cyclic voltammograms(CV) can be seen at the glassy carbon electrode. It was found that the peak current of CuL decreased significantly with a negative shift of the peak potential in the presence of DNA compared with that in the absence of DNA. In addition, the decreased absorbance of CuL was observed with increasing the concentration of DNA; the absorption spectrum of an ethidium bromide(EB)-DNA system in the presence of CuL confirms that the binding mode of CuL to DNA is different from the intercalation of EB with DNA. All the experimental results indicate that CuL can bind to DNA by electrostatic binding and form a 1∶1 association complex with a binding constant of 2.72×10 4 L/mol.
文摘Objective: To study the value of multiple MR imaging techniques in the diagnosis of pancreatic carcinoma and the assessment of resectbility of the lesion. Methods: MR imaging was performed in 18 pa-tients with surgically and/or pathologically proven pancreatic carcinoma. GRE T1WI, TSE T2WI, GRE T1WI with fat suppression, delayed enhancement GRE T1WI, MRCP and 3D DCE MRA were used in MR scanning. Tumor involvement of the celiac trunk and its main branches, superior mesenteric artery,the portal, splenic and superior mesenteric veins were prospectively graded on a 0-4 scale based on cir-cumferential contiguity of tumor to vessel. Results: On GRE T1WI and TSE T2WI all the lesions showed slightly hypointense and hyperintense, respectively; On GRE T1WI with fat suppression, all the tumors obviously appeared hypointense; On delayed enhancement GRE T1WI, the lesions displayed irregularly circular enhancement in 14 patients and well-distributed enhancement in 4 patients. MRCP showed exten-sive bile and main pancreatic duct dilatation with typical "double-duct" sign in 8 patients. On 3D DCE MRA, we thought it was unresectable with more than half circumferential involvement of tumor to vessel,so that the portal, splenic and superior mesenteric veins were involved with 56% (10/18), 39% (7/18)and 67% (12/18), respectively. The celiac trunk and its main branches and superior mesenteric arteries were involved with 22% (4/18) and 17% (3/18), respectively. The pancreatic lesions in 2 cases could be completely resected in the evaluation of MR imaging, which was fitted to the findings of operation by pan-creatoduodenectomy. The pancreatic lesions in other 2 cases were partly, resected because there was tumor extension to superior mesenteric vein and/or artery. The tumors in the remaining 14 patients were too large and involved peripancreatic vessels or there were stomach or liver metastases, so these patients were only treated by choledochojejunostomy and gastrojejunstomy. Conclusion: The "all-in-one" MR approach including fast scanning sequences, fat suppression, MRCP and 3D DCE MRA provides the surgeon with diagnosis and assessment of resectability of tlm lesion prior to surgery of pancreatic carcinoma.
文摘2020年我国伏季休渔期间中国毛虾限额捕捞试点在黄海海州湾实施,2021年该限额捕捞项目继续实施,在此背景下探究夏季海州湾中国毛虾资源分布对其限额捕捞精细化管理至关重要。首先基于2021年海州湾中国毛虾限额捕捞期间北斗渔船监控系统(Vessel monitoring system,VMS)数据提取得到各毛虾张网渔船所有捕捞网位点及其捕捞努力量,然后运用具有噪声的密度聚类(Density-based spatial clustering of application with noise,DBSCAN)算法进一步识别含有捕捞产量的网位点,从而探究夏季海州湾中国毛虾资源分布格局。结果显示,含有产量的网位点识别率为97.18%,表明DBSCAN算法能精准识别含有产量的捕捞网位点。含有产量的网位点共有898个,空间上呈聚集性分布。依据捕捞努力量情况探究得到中国毛虾资源主要分布在120°00′E~120°15′E,34°43′N~34°48′N和119°47′E~119°53′E,34°36′N~34°43′N。本研究思路可作为其他渔业捕捞活动中运用VMS数据提取含产量捕捞网位点的科学参考。
基金supported by the State“973”Key Basic Research Program(Grant No.G1999054103)the State“863”High-Tech Project(Grant No.Z19-02-05-01)+1 种基金Beijing Innovation Engineering(Grant No.955020700)the North China Pharmaceutical Corporation(NCPC)
文摘Comparative genome analysis is performed between Shigella flexneri 2a strain 301 and its close relatives, the nonpathogenic E. Coli K-12 strain MG1655. Result shows that there are 136 DNA segments whose size is larger than 1000 bp absent from Shigella flexneri 2a strain 301, which is up to 717253 bp in total length. These deleted segments altogether contain 670 open reading frames (ORFs). Prediction of these ORFs indicates that there are 40% genes of unknown function. The other genes of definite functions encode metabolic enzymes, structure proteins, transcription regulatory factors and some elements correlated with horizontal transfer. Here we compare the complete genomic sequences of the two closely related species, which differ in pathogenic phenotype. To our knowledge, this not only reveals the difference of genomic sequence between the two important enteric pathogens for the first time, but also provides valuable clues to further researches in its process of physiological activity, pathogenesis and the evolution of enteric bacteria.
文摘Background Velvet antler polypeptides (VAPs), which are derived from the antler velvets, have been reported to maintain survival and promote growth and differentiation of neural cells and, especially the development of neural tissues This study was designed to explore the influence of VAPs on neural stem cells in vitro derived from embryonic rat brain Methods Neural stem cells derived from E12 14 rat brain were isolated, cultured, and expanded for 7 days until neural stem cell aggregations and neurospheres were generated The neurospheres were cultured under the condition of different concentration of VAPs followed by immunocytochemistry to detect the differentiation of neural stem cells Results VAPs could remarkablely promote differentiation of neural stem cells and most neural stem cells were induced to differentiate towards the direction of neurons under certain concentration of VAPs Conclusion Neural stem cells can be successfully induced into neurons by VAPs in vitro , which could provide a basis for regeneration of the nervous system
文摘In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds number fluid flow applications, a subgrid turbulence model for LBM was introduced based on standard Smagorinsky subgrid model and Lattice Bhatnagar-Gross-Krook (LBGK) model. The subgrid LBGK model was subsequently used to simulate the two-dimensional driven cavity flow at high Reynolds numbers. The simulation results including distribution of stream lines, dimensionless velocities distribution, values of stream function, as well as location of vertex center, were compared with benchmark solutions, with satisfactory agreements.
