With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G)...With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications.展开更多
Coherent Jamming is one of the Important trends in modern radar electronic warfare. High-speed sampling of wldeband radio frequency （RF） signals and high isolatlon of two receive-transmit antennas are key technologi...Coherent Jamming is one of the Important trends in modern radar electronic warfare. High-speed sampling of wldeband radio frequency （RF） signals and high isolatlon of two receive-transmit antennas are key technologies for the realization of coherent jamming. However, these technologies present significant challenges to enginserlng application. In this paper, a novel repeater Jamming based on interrupted sampling technique is presented. For a Jammer with a receive-transmit time-sharing antenna, a radar signal is sampled with a low rate by the jammer. Then, a train of false targets will be achieved after the Jamming signal feed the matched flltar of a pulse compression radar. For the case of the Ilnser frequency modulated （LFM） pulse compression radars, mathematic principles of the interrupted.sampiing repeater jamming Is developed, and then the efficiency of the jamming is described and stated as expressions of key parameters which are also beneficial to the Jamming design for other coherent radars.展开更多
AIM： To compare the volumetric-modulated arc ther- apy （VMAT） plans with conventional sliding window intensity-modulated radiotherapy （c-IMRT） plans in esophageal cancer （EC）. METHODS： Twenty patients with EC ...AIM： To compare the volumetric-modulated arc ther- apy （VMAT） plans with conventional sliding window intensity-modulated radiotherapy （c-IMRT） plans in esophageal cancer （EC）. METHODS： Twenty patients with EC were selected, including 5 cases located in the cervical, the upper, the middle and the lower thorax, respectively. Five plans were generated with the eclipse planning sys- tem： three using c-IMRT with 5 fields （5F）, 7 fields （7F） and 9 fields （gF）, and two using VMAT with a single arc （1A） and double arcs （2A）. The treatment plans were designed to deliver a dose of 60 Gy to the plan-ning target volume （PTV） with the same constrains in a 2.0 Gy daily fraction, 5 d a week. Plans were normal- ized to 95% of the PTV that received 100% of the pre- scribed dose. We examined the dose-volume histogram parameters of PTV and the organs at risk （OAR） such as lungs, spinal cord and heart. Monitor units （MU） and normal tissue complication probability （NTCP） of OAR were also reported. RESULTS： Both c-IMRT and VMAT plans resulted in abundant dose coverage of PTV for EC of different Io- cations. The dose conformity to PTV was improved as the number of field in c-IMRT or rotating arc in VMAT was increased. The doses to PTV and OAR in VMAT plans were not statistically different in comparison with c-IMRT plans, with the following exceptions： in cervical and upper thoracic EC, the conformity index （CI） was higher in VMAT （1A 0.78 and 2A 0.8） than in c-IMRT （5F 0.62, 7F 0.66 and 9F 0.73） and homogeneity was slightly better in c-IMRT （7F 1.09 and 9F 1.07） than in VMAT （1A 1,1 and 2A 1.09）, Lung V30 was lower in VMAT （1A 12.52 and 2A 12.29） than in c-IMRT （7F 14.35 and 9F 14.81）. The humeral head doses were significantly increased in VMAT as against c-IMRT. In the middle and lower thoracic EC, CI in VMAT （1A 0.76 and 2A 0.74） was higher than in c-IMRT （5F 0.63 Gy and 7F 0.67 Gy）, and homogeneity was almost similar between VMAT and c-IMRT展开更多
Multiple cancer immunotherapies including chimeric antigen receptor T cell and immune checkpoint inhibitors(ICIs)have been successfully developed to treat various cancers by motivating the adaptive anti-tumor immunity...Multiple cancer immunotherapies including chimeric antigen receptor T cell and immune checkpoint inhibitors(ICIs)have been successfully developed to treat various cancers by motivating the adaptive anti-tumor immunity.Particularly,the checkpoint blockade approach has achieved great clinic success as evidenced by several U.S.Food and Drug Administration(FDA)-approved antiprogrammed death receptor 1/ligand 1 or anti-cytotoxic T lymphocyte associated protein 4 antibodies.However,the majority of cancers have low clinical response rates to these ICIs due to poor tumor immunogenicity.Indeed,the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes-TANK-binding kinase 1(cGAS-STING-TBK1)axis is now appreciated as the major signaling pathway in innate immune response across different species.Aberrant signaling of this pathway has been closely linked to multiple diseases,including auto-inflammation,virus infection and cancers.In this perspective,we provide an updated review on the latest progress on the development of small molecule modulators targeting the cGAS-STING-TBK1 signaling pathway and their preclinical and clinical use as a new immune stimulatory therapy.Meanwhile,highlights on the clinical candidates,limitations and challenges,as well as future directions in this field are also discussed.Further,small molecule inhibitors targeting this signaling axis and their potential therapeutic use for various indications are discussed as well.展开更多
In this paper, a substrate removing technique in a silicon Mach–Zehnder modulator(MZM) is proposed and demonstrated to improve modulation bandwidth. Based on the novel and optimized traveling wave electrodes,the elec...In this paper, a substrate removing technique in a silicon Mach–Zehnder modulator(MZM) is proposed and demonstrated to improve modulation bandwidth. Based on the novel and optimized traveling wave electrodes,the electrode transmission loss is reduced, and the electro-optical group index and 50 Ω impedance matching are improved, simultaneously. A 2 mm long substrate removed silicon MZM with the measured and extrapolated 3 dB electro-optical bandwidth of >50 GHz and 60 GHz at the-8 V bias voltage is designed and fabricated.Open optical eye diagrams of up to 90 GBaud∕s NRZ and 56 GBaud∕s four-level pulse amplitude modulation(PAM-4) are experimentally obtained without additional optical or digital compensations. Based on this silicon MZM, the performance in a short-reach transmission system is further investigated. Single-lane 112 Gb∕s and 128 Gb∕s transmissions over different distances of 1 km, 2 km, and 10 km are experimentally achieved based on this high-speed silicon MZM.展开更多
In modern wireless communications,digital information is frstly converted to analog signal by a digital-analog convertor,which is then mixed to high-frequency microwave to be transmitted through a series of devices in...In modern wireless communications,digital information is frstly converted to analog signal by a digital-analog convertor,which is then mixed to high-frequency microwave to be transmitted through a series of devices including modulator,mixer,amplifer,flter,and antenna and is fnally received by terminals via a reversed process.Although the wireless communication systems have evolved signifcantly over the past thirty years,the basic architecture has not been challenged.Here,we propose a method to transmit digital information directly via programmable coding metasurface.Since the coding metasurface is composed of‘0’and‘1’digital units with opposite phase responses,the digital information can be directly modulated to the metasurface with certain coding sequences and sent to space under the illumination of feeding antenna.Te information,being modulated in radiation patterns of the metasurface,can be correctly received by multiple receivers distributed in diferent locations.Tis method provides a completely new architecture for wireless communications without using complicated digital-analog convertor and a series of active/passive microwave devices.We build up a prototype to validate the new architecture experimentally,which may fnd promising applications where information security is highly demanded.展开更多
基金supported by the National High Technology Research and Development Program of China (863 program) of China under Grant No.2011AA010200 supported by the National Natural Science Foundation of China (NSFC) under Grant No.61771116 and No.91738102
文摘With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications.
文摘Coherent Jamming is one of the Important trends in modern radar electronic warfare. High-speed sampling of wldeband radio frequency （RF） signals and high isolatlon of two receive-transmit antennas are key technologies for the realization of coherent jamming. However, these technologies present significant challenges to enginserlng application. In this paper, a novel repeater Jamming based on interrupted sampling technique is presented. For a Jammer with a receive-transmit time-sharing antenna, a radar signal is sampled with a low rate by the jammer. Then, a train of false targets will be achieved after the Jamming signal feed the matched flltar of a pulse compression radar. For the case of the Ilnser frequency modulated （LFM） pulse compression radars, mathematic principles of the interrupted.sampiing repeater jamming Is developed, and then the efficiency of the jamming is described and stated as expressions of key parameters which are also beneficial to the Jamming design for other coherent radars.
基金Supported by The National Natural Science Foundation of China, No. 30870738
文摘AIM： To compare the volumetric-modulated arc ther- apy （VMAT） plans with conventional sliding window intensity-modulated radiotherapy （c-IMRT） plans in esophageal cancer （EC）. METHODS： Twenty patients with EC were selected, including 5 cases located in the cervical, the upper, the middle and the lower thorax, respectively. Five plans were generated with the eclipse planning sys- tem： three using c-IMRT with 5 fields （5F）, 7 fields （7F） and 9 fields （gF）, and two using VMAT with a single arc （1A） and double arcs （2A）. The treatment plans were designed to deliver a dose of 60 Gy to the plan-ning target volume （PTV） with the same constrains in a 2.0 Gy daily fraction, 5 d a week. Plans were normal- ized to 95% of the PTV that received 100% of the pre- scribed dose. We examined the dose-volume histogram parameters of PTV and the organs at risk （OAR） such as lungs, spinal cord and heart. Monitor units （MU） and normal tissue complication probability （NTCP） of OAR were also reported. RESULTS： Both c-IMRT and VMAT plans resulted in abundant dose coverage of PTV for EC of different Io- cations. The dose conformity to PTV was improved as the number of field in c-IMRT or rotating arc in VMAT was increased. The doses to PTV and OAR in VMAT plans were not statistically different in comparison with c-IMRT plans, with the following exceptions： in cervical and upper thoracic EC, the conformity index （CI） was higher in VMAT （1A 0.78 and 2A 0.8） than in c-IMRT （5F 0.62, 7F 0.66 and 9F 0.73） and homogeneity was slightly better in c-IMRT （7F 1.09 and 9F 1.07） than in VMAT （1A 1,1 and 2A 1.09）, Lung V30 was lower in VMAT （1A 12.52 and 2A 12.29） than in c-IMRT （7F 14.35 and 9F 14.81）. The humeral head doses were significantly increased in VMAT as against c-IMRT. In the middle and lower thoracic EC, CI in VMAT （1A 0.76 and 2A 0.74） was higher than in c-IMRT （5F 0.63 Gy and 7F 0.67 Gy）, and homogeneity was almost similar between VMAT and c-IMRT
基金supported by grants from Natural Science Foundation of China(Nos.81773565,21877120,81703327,81430080,81573452,and 81773767,China)Supporting grants from the Key Program of the Frontier Science of the Chinese Academy of Sciences(No.160621,China)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA12020374,China)a start-up grant to the Research Laboratory of Medicinal Chemical Biology&Frontiers on Drug Discovery from Shanghai Jiao Tong University(China)are also appreciated
文摘Multiple cancer immunotherapies including chimeric antigen receptor T cell and immune checkpoint inhibitors(ICIs)have been successfully developed to treat various cancers by motivating the adaptive anti-tumor immunity.Particularly,the checkpoint blockade approach has achieved great clinic success as evidenced by several U.S.Food and Drug Administration(FDA)-approved antiprogrammed death receptor 1/ligand 1 or anti-cytotoxic T lymphocyte associated protein 4 antibodies.However,the majority of cancers have low clinical response rates to these ICIs due to poor tumor immunogenicity.Indeed,the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes-TANK-binding kinase 1(cGAS-STING-TBK1)axis is now appreciated as the major signaling pathway in innate immune response across different species.Aberrant signaling of this pathway has been closely linked to multiple diseases,including auto-inflammation,virus infection and cancers.In this perspective,we provide an updated review on the latest progress on the development of small molecule modulators targeting the cGAS-STING-TBK1 signaling pathway and their preclinical and clinical use as a new immune stimulatory therapy.Meanwhile,highlights on the clinical candidates,limitations and challenges,as well as future directions in this field are also discussed.Further,small molecule inhibitors targeting this signaling axis and their potential therapeutic use for various indications are discussed as well.
文摘In this paper, a substrate removing technique in a silicon Mach–Zehnder modulator(MZM) is proposed and demonstrated to improve modulation bandwidth. Based on the novel and optimized traveling wave electrodes,the electrode transmission loss is reduced, and the electro-optical group index and 50 Ω impedance matching are improved, simultaneously. A 2 mm long substrate removed silicon MZM with the measured and extrapolated 3 dB electro-optical bandwidth of >50 GHz and 60 GHz at the-8 V bias voltage is designed and fabricated.Open optical eye diagrams of up to 90 GBaud∕s NRZ and 56 GBaud∕s four-level pulse amplitude modulation(PAM-4) are experimentally obtained without additional optical or digital compensations. Based on this silicon MZM, the performance in a short-reach transmission system is further investigated. Single-lane 112 Gb∕s and 128 Gb∕s transmissions over different distances of 1 km, 2 km, and 10 km are experimentally achieved based on this high-speed silicon MZM.
基金The authors acknowledge supports by National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)National Natural Science Foundation of China(61631007,61571117,61501112,61501117,61522106,61731010,61735010,61722106,61701107,and 61701108)111 Project(No.111-2-05).
文摘In modern wireless communications,digital information is frstly converted to analog signal by a digital-analog convertor,which is then mixed to high-frequency microwave to be transmitted through a series of devices including modulator,mixer,amplifer,flter,and antenna and is fnally received by terminals via a reversed process.Although the wireless communication systems have evolved signifcantly over the past thirty years,the basic architecture has not been challenged.Here,we propose a method to transmit digital information directly via programmable coding metasurface.Since the coding metasurface is composed of‘0’and‘1’digital units with opposite phase responses,the digital information can be directly modulated to the metasurface with certain coding sequences and sent to space under the illumination of feeding antenna.Te information,being modulated in radiation patterns of the metasurface,can be correctly received by multiple receivers distributed in diferent locations.Tis method provides a completely new architecture for wireless communications without using complicated digital-analog convertor and a series of active/passive microwave devices.We build up a prototype to validate the new architecture experimentally,which may fnd promising applications where information security is highly demanded.
