AIM: To investigate the impact of RAS and BRAF mutations on the pattern of metastatic disease and carcinoembryonic antigen(CEA) production.METHODS: In this retrospective study, we investigated the impact of RAS and BR...AIM: To investigate the impact of RAS and BRAF mutations on the pattern of metastatic disease and carcinoembryonic antigen(CEA) production.METHODS: In this retrospective study, we investigated the impact of RAS and BRAF mutational status on pattern of metastatic disease and CEA production. Only patients presenting with a newly diagnosed metastatic colorectal cancer(CRC) were included. Patients' characteristics, primary tumor location, site of metastatic disease and CEA at presentation were compared between those with and without RAS and BRAF mutations.RESULTS: Among 174 patients, mutations in KRAS, NRAS and BRAF were detected in 47%, 3% and 6% respectively. RAS mutations(KRAS and NRAS) were more likely to be found in African American patients(87% vs 13%; P value = 0.0158). RAS mutations were associated with a higher likelihood of a normal CEA(< 5 ng/mL) at presentation. BRAF mutations were more likely to occur in females. We were not able to confirm any association between mutational status and site of metastatic disease at initial diagnosis.CONCLUSION: No association was found between RAS and BRAF mutations and sites of metastatic disease at the time of initial diagnosis in our cohort. Patients with RAS mutations were more likely to present with CEA levels < 5 ng/mL. These findings may have clinical implications on surveillance strategies for RAS mutant patients with earlier stages of CRC.展开更多
A new class of compact and lightweight S-band 1 kW traveling-wave tube (TWT) is being developed for a microwave power module (MPM) that will be used for phased antenna array radar applications. The proposed S-band MPM...A new class of compact and lightweight S-band 1 kW traveling-wave tube (TWT) is being developed for a microwave power module (MPM) that will be used for phased antenna array radar applications. The proposed S-band MPM provides a tenfold peak power increase compared to state-of-the-art S-band MPMs. In this paper, the design of the vacuum power booster TWT part of the MPM is presented. The compact and lightweight S-band TWT is driven by a 6 kV, 0.9 A electron beam. The amplifier is predicted by large-signal simulations to generate over 1 kW at S-band with 25 dB saturated gain and over 40% efficiency. The stability from unwanted oscillations has been investigated. To suppress the oscillations, the helix circuit has been coated with carbon composite material. The coaxial input and output antennas have been fabricated. For efficiency enhancement, a multi-stage depressed collector (MDC) has been designed using a 3D particle-in-cell (PIC) simulator, VORPAL. The collector design makes use of a current loop based on a feedback mechanism for effective design process. The integrated designs of a helix circuit, an electron gun, a periodic permanent magnet (PPM), antennas, and a collector are presented.展开更多
The popularization of intelligent healthcare devices and big data analytics significantly boosts the development of Smart Healthcare Networks(SHNs).To enhance the precision of diagnosis,different participants in SHNs ...The popularization of intelligent healthcare devices and big data analytics significantly boosts the development of Smart Healthcare Networks(SHNs).To enhance the precision of diagnosis,different participants in SHNs share health data that contain sensitive information.Therefore,the data exchange process raises privacy concerns,especially when the integration of health data from multiple sources(linkage attack)results in further leakage.Linkage attack is a type of dominant attack in the privacy domain,which can leverage various data sources for private data mining.Furthermore,adversaries launch poisoning attacks to falsify the health data,which leads to misdiagnosing or even physical damage.To protect private health data,we propose a personalized differential privacy model based on the trust levels among users.The trust is evaluated by a defined community density,while the corresponding privacy protection level is mapped to controllable randomized noise constrained by differential privacy.To avoid linkage attacks in personalized differential privacy,we design a noise correlation decoupling mechanism using a Markov stochastic process.In addition,we build the community model on a blockchain,which can mitigate the risk of poisoning attacks during differentially private data transmission over SHNs.Extensive experiments and analysis on real-world datasets have testified the proposed model,and achieved better performance compared with existing research from perspectives of privacy protection and effectiveness.展开更多
An equivalence is made between the exceptional points proposed by the field of non-Hermitian quantum mechanics and the dead band observed in laser gyroscopes.The sensitivity enhancement near this exceptional point is ...An equivalence is made between the exceptional points proposed by the field of non-Hermitian quantum mechanics and the dead band observed in laser gyroscopes.The sensitivity enhancement near this exceptional point is plagued by increased uncertainty due to broadening of the beat-note bandwidth.Also,near the dead band the gyroscope response is caused by Rabi intensity oscillations and not solely by a phase modulation.Finally,a distinction is made between conservative and non-conservative coupling.展开更多
文摘AIM: To investigate the impact of RAS and BRAF mutations on the pattern of metastatic disease and carcinoembryonic antigen(CEA) production.METHODS: In this retrospective study, we investigated the impact of RAS and BRAF mutational status on pattern of metastatic disease and CEA production. Only patients presenting with a newly diagnosed metastatic colorectal cancer(CRC) were included. Patients' characteristics, primary tumor location, site of metastatic disease and CEA at presentation were compared between those with and without RAS and BRAF mutations.RESULTS: Among 174 patients, mutations in KRAS, NRAS and BRAF were detected in 47%, 3% and 6% respectively. RAS mutations(KRAS and NRAS) were more likely to be found in African American patients(87% vs 13%; P value = 0.0158). RAS mutations were associated with a higher likelihood of a normal CEA(< 5 ng/mL) at presentation. BRAF mutations were more likely to occur in females. We were not able to confirm any association between mutational status and site of metastatic disease at initial diagnosis.CONCLUSION: No association was found between RAS and BRAF mutations and sites of metastatic disease at the time of initial diagnosis in our cohort. Patients with RAS mutations were more likely to present with CEA levels < 5 ng/mL. These findings may have clinical implications on surveillance strategies for RAS mutant patients with earlier stages of CRC.
文摘A new class of compact and lightweight S-band 1 kW traveling-wave tube (TWT) is being developed for a microwave power module (MPM) that will be used for phased antenna array radar applications. The proposed S-band MPM provides a tenfold peak power increase compared to state-of-the-art S-band MPMs. In this paper, the design of the vacuum power booster TWT part of the MPM is presented. The compact and lightweight S-band TWT is driven by a 6 kV, 0.9 A electron beam. The amplifier is predicted by large-signal simulations to generate over 1 kW at S-band with 25 dB saturated gain and over 40% efficiency. The stability from unwanted oscillations has been investigated. To suppress the oscillations, the helix circuit has been coated with carbon composite material. The coaxial input and output antennas have been fabricated. For efficiency enhancement, a multi-stage depressed collector (MDC) has been designed using a 3D particle-in-cell (PIC) simulator, VORPAL. The collector design makes use of a current loop based on a feedback mechanism for effective design process. The integrated designs of a helix circuit, an electron gun, a periodic permanent magnet (PPM), antennas, and a collector are presented.
基金supported by the National Key Research and Development Program of China(No.2021YFF0900400).
文摘The popularization of intelligent healthcare devices and big data analytics significantly boosts the development of Smart Healthcare Networks(SHNs).To enhance the precision of diagnosis,different participants in SHNs share health data that contain sensitive information.Therefore,the data exchange process raises privacy concerns,especially when the integration of health data from multiple sources(linkage attack)results in further leakage.Linkage attack is a type of dominant attack in the privacy domain,which can leverage various data sources for private data mining.Furthermore,adversaries launch poisoning attacks to falsify the health data,which leads to misdiagnosing or even physical damage.To protect private health data,we propose a personalized differential privacy model based on the trust levels among users.The trust is evaluated by a defined community density,while the corresponding privacy protection level is mapped to controllable randomized noise constrained by differential privacy.To avoid linkage attacks in personalized differential privacy,we design a noise correlation decoupling mechanism using a Markov stochastic process.In addition,we build the community model on a blockchain,which can mitigate the risk of poisoning attacks during differentially private data transmission over SHNs.Extensive experiments and analysis on real-world datasets have testified the proposed model,and achieved better performance compared with existing research from perspectives of privacy protection and effectiveness.
基金Marshall Space Flight Center(80MSFC19M0042)NASA SBIR(80NSSC19C0505)。
文摘An equivalence is made between the exceptional points proposed by the field of non-Hermitian quantum mechanics and the dead band observed in laser gyroscopes.The sensitivity enhancement near this exceptional point is plagued by increased uncertainty due to broadening of the beat-note bandwidth.Also,near the dead band the gyroscope response is caused by Rabi intensity oscillations and not solely by a phase modulation.Finally,a distinction is made between conservative and non-conservative coupling.
