Telecom operators are deploying the fifth generation(5G) networks around the world which promises high information transmission rate, wide network coverage, low communication delay, and easy access to a large number o...Telecom operators are deploying the fifth generation(5G) networks around the world which promises high information transmission rate, wide network coverage, low communication delay, and easy access to a large number of devices. However, during the construction and operation of 5G, telecom operators face many challenges, such as insufficient frequency resources, low efficiency of network management, information opacity, risks of data interoperability, and network privacy vulnerabilities. As 5G is generally deployed in heterogeneous networks with massive ubiquitous devices, it is quite necessary to provide secure and decentralized solutions. Blockchain is a distributed system maintained by multiple parties with inherit features including decentralization,traceability and tamperproof. These features collectively contribute to a new application ecosystem where transactions are secure and trustworthy. Therefore,blockchain is expected to integrate with 5G networks to build safer and more reliable mobile network infrastructures. This paper firstly discusses the merits of blockchain technology and the benefits of integrating it with 5G networks. Then a variety of applications of blockchain technology in telecom network operation are reviewed, including spectrum sharing, international roaming settlement, network operation management, number selection management and supply chain management. In the end, we show our recently advance in integrating blockchain in 5G by introducing a multi framework based blockchain service network architecture deployed in real environment.展开更多
Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotub...Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotube buckypaper(S/CoxS/BP)by a facile electrodeposition method and are used as a binder-free high-performance cathode for LSBs.Elemental sulfur is deposited on buckypaper by electrooxidation of a polysulfide solution(-S6^2-).This approach substantially increased the current and time efficiency of sulfur electrochemical deposition on conductive material for LSBs.S/CoxS/BP cathode could deliver an initial discharge capacity as high as 1650 mAh g^-1 at 0.1 C,which is close to the theoretical capacity of sulfur.At current rate of 0.5 C,the S/CoxS/BP has a capacity of 1420 mAh g^-1 at the first cycle and 715 mAh g^-1 after 500 cycles with a fading rate of 0.099%per cycle.The high capacity of S/CoxS/BP is attributed to both the homogeneous dispersion of nanosized sulfur within BP and the presence of CoxS catalyst.The sodium dodecyl sulfate(SDS)pretreatment of BP renders it polarity to bind polysulfides and thus facilitates the good dispersibility of nanosized sulfur within BP.CoxS catalyst accelerates the kinetics of polysulfide conversion and reduces the presence of polysulfide in the cathode,which suppresses the polysulfide diffusion to anode,i.e.,the shuttle effect.The mitigation of the active material loss improves not only the capacity but also the cyclability of S/CoxS/BP.展开更多
Caenorhabditis elegans hid-1 gene was first identified in a screen for mutants with a high-temperature-induced dauer formation(Hid)phenotype.Despite the fact that the hid-1 gene encodes a novel protein(HID-1)which is ...Caenorhabditis elegans hid-1 gene was first identified in a screen for mutants with a high-temperature-induced dauer formation(Hid)phenotype.Despite the fact that the hid-1 gene encodes a novel protein(HID-1)which is highly conserved from Caenorhabditis elegans to mammals,the domain structure,subcellular localization,and exact function of HID-1 remain unknown.Previous studies and various bioinformatic softwares predicted that HID-1 contained many transmembrane domains but no known functional domain.In this study,we revealed that mammalian HID-1 localized to the medial-and transGolgi apparatus as well as the cytosol,and the localization was sensitive to brefeldin A treatment.Next,we demonstrated that HID-1 was a peripheral membrane protein and dynamically shuttled between the Golgi apparatus and the cytosol.Finally,we verified that a conserved N-terminal myristoylation site was required for HID-1 binding to the Golgi apparatus.We propose that HID-1 is probably involved in the intracellular trafficking within the Golgi region.展开更多
Thyroglossal duct carcinoma,which is usually diagnosed postoperatively,is a rare malignant tumor arising in the thyroglossal duct cyst.The definitive diagnosis can be made only after microscopic examination.We retrosp...Thyroglossal duct carcinoma,which is usually diagnosed postoperatively,is a rare malignant tumor arising in the thyroglossal duct cyst.The definitive diagnosis can be made only after microscopic examination.We retrospectively reviewed three cases of thyroglossal duct carcinoma diagnosed in Peking University School and Hospital of Stomatology from January 1986 to August 2006.Clinical and pathological features were investigated and the optimal treatment protocol was proposed.The constituent ratio of thyroglossal duct carcinoma among surgically excised thyroglossal duct lesions was 2.9%.The clinical presentation of thyroglossal duct carcinoma was very similar to that of its benign counterpart.Two cases were diagnosed as thyroglossal duct cyst prior to the operation,the remaining one as dermoid cyst.All three cases were diagnosed as papillary carcinoma of thyroid origin after microscopic examination.Primary thyroglossal duct carcinoma should conform to the following criteria:localization of the carcinoma to a clearly demonstrable thyroglossal duct cyst or tract;clinically or histologically confirmed absence of carcinoma of the thyroid gland.Papillary carcinoma is the most common histological type,which usually develops slowly with an excellent prognosis.The histological characteristics including:formation of papillary structure;nuclear morphological variations such as ground glass nuclei,pseudoinclusions,intranuclear grooves and filaments;concentrically calcified structures termed psammoma bodies which is regarded as a strong indication of papillary carcinoma;and positivity in immunohistological staining for thyroglobin.Sistrunk procedure of excision is the choice for treatment.A close follow-up is needed.In the presence of thyroid gland masses or cervical lymphadenopathy,thyroidectomy or neck dissection should be recommended.The effect of thyroid suppression therapy and radioactive iodine therapy is not conclusive.展开更多
文摘Telecom operators are deploying the fifth generation(5G) networks around the world which promises high information transmission rate, wide network coverage, low communication delay, and easy access to a large number of devices. However, during the construction and operation of 5G, telecom operators face many challenges, such as insufficient frequency resources, low efficiency of network management, information opacity, risks of data interoperability, and network privacy vulnerabilities. As 5G is generally deployed in heterogeneous networks with massive ubiquitous devices, it is quite necessary to provide secure and decentralized solutions. Blockchain is a distributed system maintained by multiple parties with inherit features including decentralization,traceability and tamperproof. These features collectively contribute to a new application ecosystem where transactions are secure and trustworthy. Therefore,blockchain is expected to integrate with 5G networks to build safer and more reliable mobile network infrastructures. This paper firstly discusses the merits of blockchain technology and the benefits of integrating it with 5G networks. Then a variety of applications of blockchain technology in telecom network operation are reviewed, including spectrum sharing, international roaming settlement, network operation management, number selection management and supply chain management. In the end, we show our recently advance in integrating blockchain in 5G by introducing a multi framework based blockchain service network architecture deployed in real environment.
基金conducted by Nanomaterials for Energy and Energy-Water Nexus(NEW)Programme under Singapore-HUJ Alliance for Research and Enterprise(SHARE)in the Campus for Research Excellence and Technological Enterprise(CREATE)that is supported by the National Research Foundation,Prime Minister’s O ce,Singaporesupported also by the Israel National Research Center for Electrochemical Propulsion(INREP)。
文摘Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotube buckypaper(S/CoxS/BP)by a facile electrodeposition method and are used as a binder-free high-performance cathode for LSBs.Elemental sulfur is deposited on buckypaper by electrooxidation of a polysulfide solution(-S6^2-).This approach substantially increased the current and time efficiency of sulfur electrochemical deposition on conductive material for LSBs.S/CoxS/BP cathode could deliver an initial discharge capacity as high as 1650 mAh g^-1 at 0.1 C,which is close to the theoretical capacity of sulfur.At current rate of 0.5 C,the S/CoxS/BP has a capacity of 1420 mAh g^-1 at the first cycle and 715 mAh g^-1 after 500 cycles with a fading rate of 0.099%per cycle.The high capacity of S/CoxS/BP is attributed to both the homogeneous dispersion of nanosized sulfur within BP and the presence of CoxS catalyst.The sodium dodecyl sulfate(SDS)pretreatment of BP renders it polarity to bind polysulfides and thus facilitates the good dispersibility of nanosized sulfur within BP.CoxS catalyst accelerates the kinetics of polysulfide conversion and reduces the presence of polysulfide in the cathode,which suppresses the polysulfide diffusion to anode,i.e.,the shuttle effect.The mitigation of the active material loss improves not only the capacity but also the cyclability of S/CoxS/BP.
基金the National Science Foundation of China(Grant Nos.30870564,and 30900268),The Beijing Natural Science Foundation(No.5092017)the Major State Basic Research Program of China(No.2010CB833701)the CAS Project(KSCX2-SW-224 and Novo Nordisk-CAS to P Xu).
文摘Caenorhabditis elegans hid-1 gene was first identified in a screen for mutants with a high-temperature-induced dauer formation(Hid)phenotype.Despite the fact that the hid-1 gene encodes a novel protein(HID-1)which is highly conserved from Caenorhabditis elegans to mammals,the domain structure,subcellular localization,and exact function of HID-1 remain unknown.Previous studies and various bioinformatic softwares predicted that HID-1 contained many transmembrane domains but no known functional domain.In this study,we revealed that mammalian HID-1 localized to the medial-and transGolgi apparatus as well as the cytosol,and the localization was sensitive to brefeldin A treatment.Next,we demonstrated that HID-1 was a peripheral membrane protein and dynamically shuttled between the Golgi apparatus and the cytosol.Finally,we verified that a conserved N-terminal myristoylation site was required for HID-1 binding to the Golgi apparatus.We propose that HID-1 is probably involved in the intracellular trafficking within the Golgi region.
文摘Thyroglossal duct carcinoma,which is usually diagnosed postoperatively,is a rare malignant tumor arising in the thyroglossal duct cyst.The definitive diagnosis can be made only after microscopic examination.We retrospectively reviewed three cases of thyroglossal duct carcinoma diagnosed in Peking University School and Hospital of Stomatology from January 1986 to August 2006.Clinical and pathological features were investigated and the optimal treatment protocol was proposed.The constituent ratio of thyroglossal duct carcinoma among surgically excised thyroglossal duct lesions was 2.9%.The clinical presentation of thyroglossal duct carcinoma was very similar to that of its benign counterpart.Two cases were diagnosed as thyroglossal duct cyst prior to the operation,the remaining one as dermoid cyst.All three cases were diagnosed as papillary carcinoma of thyroid origin after microscopic examination.Primary thyroglossal duct carcinoma should conform to the following criteria:localization of the carcinoma to a clearly demonstrable thyroglossal duct cyst or tract;clinically or histologically confirmed absence of carcinoma of the thyroid gland.Papillary carcinoma is the most common histological type,which usually develops slowly with an excellent prognosis.The histological characteristics including:formation of papillary structure;nuclear morphological variations such as ground glass nuclei,pseudoinclusions,intranuclear grooves and filaments;concentrically calcified structures termed psammoma bodies which is regarded as a strong indication of papillary carcinoma;and positivity in immunohistological staining for thyroglobin.Sistrunk procedure of excision is the choice for treatment.A close follow-up is needed.In the presence of thyroid gland masses or cervical lymphadenopathy,thyroidectomy or neck dissection should be recommended.The effect of thyroid suppression therapy and radioactive iodine therapy is not conclusive.
