When an unruptured aneurysm is found, deciding whether to operate or follow up is one of the most important issues. There are guidelines for making the best final decision on treatment, taking into account the effecti...When an unruptured aneurysm is found, deciding whether to operate or follow up is one of the most important issues. There are guidelines for making the best final decision on treatment, taking into account the effectiveness of diagnostic and therapeutic devices and the risk-benefit ratio of patients, caregivers, and healthcare professionals. The guidelines evidence-based of large clinical data for this purpose are presented by national medical societies. As one of the rupture risk indicators, there is the hazard risk ratio derived by the UCAS Japan research group based on the statistical method of 6697 aneurysms in 5720 patients with cerebral aneurysms of 3 mm or more. Therefore, we investigated the biomechanical significance of this hazard risk ratio using a spherical aneurysm model. It was revealed that 1) the reason why the frequency of aneurysm rupture is relatively high up to about 10 mm, 2) the UCAS hazard risk ratio corresponds to stress of the aneurysm wall, and the true stress can be calculated by multiplying the patient’s blood pressure, and 3) the factors that cause the daughter’s sac (irregular protrusion of the aneurysm wall). In addition, our two methods for measuring the strength of the blood vessel wall of an individual patient were described.展开更多
Due to the potential capacity-boosting for wireless communications,radio vortex wireless communication(RowComm)over orthogonal states/modes of orbital angular momentum(OAM)has been paid much attention to in recent yea...Due to the potential capacity-boosting for wireless communications,radio vortex wireless communication(RowComm)over orthogonal states/modes of orbital angular momentum(OAM)has been paid much attention to in recent years.A uniform circular array(UCA),as an efficient and convenient antenna structure,can transmit/receive multiple OAM beams with different OAM-modes simultaneously when the transmitter and receiver are aligned.However,for high-order OAMmodes,the OAM beams are divergent accompanied by severe attenuation.Thus,it is difficult to directly use high-order OAM-modes to achieve high capacity for RowComms.To obtain high capacity potentially offered by OAM-modes,in this paper we transform the singular UCA into the concentric UCAs,where high capacity can be achieved using multiple parallel low-order OAM-modes instead of all high-order OAM-modes,to increase the capacity of transmitter-receiver aligned Row-Comms.In particular,we study two cases:1).concentric UCAs based RowComms without co-mode interference;2).concentric UCAs based RowComms with co-mode interference.We propose a co-mode-interference-free and a co-mode-interference-contained mode-decomposition schemes to recover transmitted signals for these two cases,respectively.Additionally,we develop optimal power allocation schemes to maximize the capacity for these two cases.Numerical simulations are presented to validate and evaluate that our developed concentric UCAs based low-order RowComms can significantly increase the capacity as compared with that of singular UCA based RowComms.展开更多
Recently,uniform circular array(UCA)based orbital angular momentum(OAM)beam steering schemes have been proposed to overcome the limitations of coaxial transmission.Unlike the traditional multiple-input-multiple-output...Recently,uniform circular array(UCA)based orbital angular momentum(OAM)beam steering schemes have been proposed to overcome the limitations of coaxial transmission.Unlike the traditional multiple-input-multiple-output(MIMO)beam steering,OAM beam steering includes both the OAM generation and the beam steering.Generally,the true time delay(TTD)or the phase shifter(PS)are required for beam steering in the radio domain.Previous studies suggest that TTD is preferred for wideband MIMO beam steering to avoid beam squint caused by PS.However,in this paper,we theoretically prove that to generate the OAM beam ideally,PS should be used,while TTD deteriorates the mode orthogonality,which is influenced by the relative bandwidth.Once the ideal OAM beam is generated,TTD is required to prevent beam squint.Based on this analysis,we propose to use the two-stage phase-shifting(TSPS)architecture for OAM beam steering:PS for OAM generation and TTD for beam steering.Simulation results suggest that compared to the spectrum efficiency(SE)of PS based OAM communication,the SE based on the TTD significantly declines as the relative bandwidth increases.Furthermore,OAM beam steering using the TSPS architecture greatly outperforms systems that adopt a single TTD or PS network.展开更多
The published article titled“UCA1 Regulates the Growth and Metastasis of Pancreatic Cancer by Sponging miR-135a”has been retracted from Oncology Research,Vol.25,No.9,2017,pp.1529–1541.DOI:10.3727/096504017X14888987...The published article titled“UCA1 Regulates the Growth and Metastasis of Pancreatic Cancer by Sponging miR-135a”has been retracted from Oncology Research,Vol.25,No.9,2017,pp.1529–1541.DOI:10.3727/096504017X14888987683152 URL:https://www.techscience.com/or/v25n9/56938 Following the publication,concerns have been raised about a number of figures in this article.An unexpected area of similarity was identified in terms of the cellular data,where the results from differently performed experiments were intended to have been shown,although the areas immediately surrounding this area featured comparatively different distributions of cells.展开更多
文摘When an unruptured aneurysm is found, deciding whether to operate or follow up is one of the most important issues. There are guidelines for making the best final decision on treatment, taking into account the effectiveness of diagnostic and therapeutic devices and the risk-benefit ratio of patients, caregivers, and healthcare professionals. The guidelines evidence-based of large clinical data for this purpose are presented by national medical societies. As one of the rupture risk indicators, there is the hazard risk ratio derived by the UCAS Japan research group based on the statistical method of 6697 aneurysms in 5720 patients with cerebral aneurysms of 3 mm or more. Therefore, we investigated the biomechanical significance of this hazard risk ratio using a spherical aneurysm model. It was revealed that 1) the reason why the frequency of aneurysm rupture is relatively high up to about 10 mm, 2) the UCAS hazard risk ratio corresponds to stress of the aneurysm wall, and the true stress can be calculated by multiplying the patient’s blood pressure, and 3) the factors that cause the daughter’s sac (irregular protrusion of the aneurysm wall). In addition, our two methods for measuring the strength of the blood vessel wall of an individual patient were described.
文摘Due to the potential capacity-boosting for wireless communications,radio vortex wireless communication(RowComm)over orthogonal states/modes of orbital angular momentum(OAM)has been paid much attention to in recent years.A uniform circular array(UCA),as an efficient and convenient antenna structure,can transmit/receive multiple OAM beams with different OAM-modes simultaneously when the transmitter and receiver are aligned.However,for high-order OAMmodes,the OAM beams are divergent accompanied by severe attenuation.Thus,it is difficult to directly use high-order OAM-modes to achieve high capacity for RowComms.To obtain high capacity potentially offered by OAM-modes,in this paper we transform the singular UCA into the concentric UCAs,where high capacity can be achieved using multiple parallel low-order OAM-modes instead of all high-order OAM-modes,to increase the capacity of transmitter-receiver aligned Row-Comms.In particular,we study two cases:1).concentric UCAs based RowComms without co-mode interference;2).concentric UCAs based RowComms with co-mode interference.We propose a co-mode-interference-free and a co-mode-interference-contained mode-decomposition schemes to recover transmitted signals for these two cases,respectively.Additionally,we develop optimal power allocation schemes to maximize the capacity for these two cases.Numerical simulations are presented to validate and evaluate that our developed concentric UCAs based low-order RowComms can significantly increase the capacity as compared with that of singular UCA based RowComms.
基金Shanghai 20246G Technology Innovation and Future Industry Development Project under grant 24DP1501204。
文摘Recently,uniform circular array(UCA)based orbital angular momentum(OAM)beam steering schemes have been proposed to overcome the limitations of coaxial transmission.Unlike the traditional multiple-input-multiple-output(MIMO)beam steering,OAM beam steering includes both the OAM generation and the beam steering.Generally,the true time delay(TTD)or the phase shifter(PS)are required for beam steering in the radio domain.Previous studies suggest that TTD is preferred for wideband MIMO beam steering to avoid beam squint caused by PS.However,in this paper,we theoretically prove that to generate the OAM beam ideally,PS should be used,while TTD deteriorates the mode orthogonality,which is influenced by the relative bandwidth.Once the ideal OAM beam is generated,TTD is required to prevent beam squint.Based on this analysis,we propose to use the two-stage phase-shifting(TSPS)architecture for OAM beam steering:PS for OAM generation and TTD for beam steering.Simulation results suggest that compared to the spectrum efficiency(SE)of PS based OAM communication,the SE based on the TTD significantly declines as the relative bandwidth increases.Furthermore,OAM beam steering using the TSPS architecture greatly outperforms systems that adopt a single TTD or PS network.
文摘The published article titled“UCA1 Regulates the Growth and Metastasis of Pancreatic Cancer by Sponging miR-135a”has been retracted from Oncology Research,Vol.25,No.9,2017,pp.1529–1541.DOI:10.3727/096504017X14888987683152 URL:https://www.techscience.com/or/v25n9/56938 Following the publication,concerns have been raised about a number of figures in this article.An unexpected area of similarity was identified in terms of the cellular data,where the results from differently performed experiments were intended to have been shown,although the areas immediately surrounding this area featured comparatively different distributions of cells.
