In this paper, the problem of abnormal spectrum usage between satellite spectrum sharing systems is investigated to support multi-satellite spectrum coexistence. Given the cost of monitoring, the mobility of low-orbit...In this paper, the problem of abnormal spectrum usage between satellite spectrum sharing systems is investigated to support multi-satellite spectrum coexistence. Given the cost of monitoring, the mobility of low-orbit satellites, and the directional nature of their signals, traditional monitoring methods are no longer suitable, especially in the case of multiple power level. Mobile crowdsensing(MCS), as a new technology, can make full use of idle resources to complete a variety of perceptual tasks. However, traditional MCS heavily relies on a centralized server and is vulnerable to single point of failure attacks. Therefore, we replace the original centralized server with a blockchain-based distributed service provider to enable its security. Therefore, in this work, we propose a blockchain-based MCS framework, in which we explain in detail how this framework can achieve abnormal frequency behavior monitoring in an inter-satellite spectrum sharing system. Then, under certain false alarm probability, we propose an abnormal spectrum detection algorithm based on mixed hypothesis test to maximize detection probability in single power level and multiple power level scenarios, respectively. Finally, a Bad out of Good(BooG) detector is proposed to ease the computational pressure on the blockchain nodes. Simulation results show the effectiveness of the proposed framework.展开更多
●AIM:To evaluate the role of semaphorin 7A(Sema7A)and its associated regulatory mechanisms in modulating the barrier function of cultured human corneal epithelial cells(HCEs).●METHODS:Barrier models of HCEs were tre...●AIM:To evaluate the role of semaphorin 7A(Sema7A)and its associated regulatory mechanisms in modulating the barrier function of cultured human corneal epithelial cells(HCEs).●METHODS:Barrier models of HCEs were treated with recombinant human Sema7A at concentrations of 0,125,250,or 500 ng/mL for 24,48,or 72h in vitro.Transepithelial electrical resistance(TEER)as well as Dextran-fluorescein isothiocyanate(FITC)permeability assays were conducted to assess barrier function.To quantify tight junctions(TJs)such as occludin and zonula occludens-1(ZO-1)at the mRNA level,reverse transcriptionpolymerase chain reaction(RT-PCR)analysis was performed.Immunoblotting was used to examine the activity of the nuclear factor-kappa B(NF-κB)signaling pathway and the production of TJs proteins.Immunofluorescence analyses were employed to localize the TJs.Enzyme-linked immunosorbent assay(ELISA)and RT-PCR were utilized to observe changes in interleukin(IL)-1βlevels.To investigate the role of NF-κB signaling activation and IL^(-1)βin Sema7A’s anti-barrier mechanism,we employed 0.1μmol/L IκB kinase 2(IKK2)inhibitor IV or 500 ng/mL IL^(-1)receptor(IL-1R)antagonist.●RESULTS:Treatment with Sema7A resulted in decreased TEER and increased permeability of Dextran-FITC in HCEs through down-regulating mRNA and protein levels of TJs in a time-and dose-dependent manner,as well as altering the localization of TJs.Furthermore,Sema7A stimulated the activation of inhibitor of kappa B alpha(IκBα)and expression of IL-1β.The anti-barrier function of Sema7A was significantly suppressed by treatment with IKK2 inhibitor IV or IL-1R antagonists.●CONCLUSION:Sema7A disrupts barrier function through its influence on NF-κB-mediated expression of TJ proteins,as well as the expression of IL-1β.These findings suggest that Sema7A could be a potential therapeutic target for the diseases in corneal epithelium.展开更多
Objective To identify factors affecting the efficacy of steroid-eluting sinus stents implanted after endoscopic sinus surgery(ESS)in patients with chronic rhinosinusitis with nasal polyps(CRSwNP).Methods We performed ...Objective To identify factors affecting the efficacy of steroid-eluting sinus stents implanted after endoscopic sinus surgery(ESS)in patients with chronic rhinosinusitis with nasal polyps(CRSwNP).Methods We performed a post-hoc analysis of a randomized self-controlled clinical trial on post-operative implantation of bioabsorbable steroid-eluting stents in patients with CRSwNP.Univariate logistic regression analysis was conducted to identify which of the following factors affect the response to post-operative stent implantation:sex,serum eosinophil levels,history of prior surgery,endoscopic scores,and comorbid conditions(asthma and allergic rhinitis).The primary outcome was the rate of post-operative intervention on day 30,and the secondary outcome was the rate of polypoid tissue formation(grades 2–3)on days 14,30,and 90.Results A total of 151 patients with CRSwNP were included in the post-hoc analysis.Asthma was identified as the only risk factor for a poor response to steroid-eluting sinus stents on post-operative day 30,with an odds ratio of 23.71(95%CI,2.81,200.16;P=0.004)for the need for post-operative intervention and 19(95%CI,2.20,164.16;P=0.003)for moderate-to-severe polypoid tissue formation.In addition,the asthmatic group showed higher rates of post-operative intervention and polypoid tissue formation than the non-asthmatic group on post-operative day 30.Blood eosinophil levels were not identified as a risk factor for poor outcomes after stent implantation.Conclusion Comorbid asthma,but not blood eosinophil level,impairs the efficacy of steroid-eluting sinus stents in the short term after ESS in patients with CRSwNP.展开更多
Purpose:To evaluate the feasibility and efficacy of a transmesenteric vein extrahepatic portosystemic shunt(TmEPS)for the treatment of cavernous transformation of the portal vein(CTPV).Materials and methods:The clinic...Purpose:To evaluate the feasibility and efficacy of a transmesenteric vein extrahepatic portosystemic shunt(TmEPS)for the treatment of cavernous transformation of the portal vein(CTPV).Materials and methods:The clinical data of 20 patients with CTPV who underwent TmEPS between December 2020and January 2022 at Henan Provincial People’s Hospital were retrospectively collected.The superior mesenteric vein(SMV)trunk was patent or partially occluded in these patients.An extrahepatic portosystemic shunt between the inferior vena cava and the SMV was established using a stent graft through an infraumbilical median longitudinal mini-laparotomy.The technical success,efficacy,and complication rates were evaluated,and the preand postoperative SMV pressures were compared.Patients’clinical outcomes and shunt patency were assessed.Results:TmEPS was successfully performed in 20 patients.The initial puncture success rate of the balloon-assisted puncture technique is 95%.The mean SMV pressure decreased from 29.1±2.9 mmHg to 15.6±3.3 mmHg(p<0.001).All symptoms of portal hypertension resolved.No fatal procedural complications occurred.During the follow-up period,hepatic encephalopathy occurred in two patients.The remaining patients remained asymptomatic.All shunts were patent.Conclusions:TmEPS is a feasible,safe,and effective treatment option for patients with CTPV.展开更多
This paper investigates the problem of path tracking control for autonomous ground vehicles(AGVs),where the input saturation,system nonlinearities and uncertainties are considered.Firstly,the nonlinear path tracking s...This paper investigates the problem of path tracking control for autonomous ground vehicles(AGVs),where the input saturation,system nonlinearities and uncertainties are considered.Firstly,the nonlinear path tracking system is formulated as a linear parameter varying(LPV)model where the variation of vehicle velocity is taken into account.Secondly,considering the noise effects on the measurement of lateral offset and heading angle,an observer-based control strategy is proposed,and by analyzing the frequency domain characteristics of the derivative of desired heading angle,a finite frequency H_∞index is proposed to attenuate the effects of the derivative of desired heading angle on path tracking error.Thirdly,sufficient conditions are derived to guarantee robust H_∞performance of the path tracking system,and the calculation of observer and controller gains is converted into solving a convex optimization problem.Finally,simulation examples verify the advantages of the control method proposed in this paper.展开更多
In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at b...In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at beamforming mode,which requires a realistic non-stationary channel environment.For the dynamic propagation emulation,an efficient closed-form probe weighting strategy minimizing the power angular spectrum(PAS)emulation errors is derived,substantially reducing the associated computational complexity.On the other hand,a novel probe selection algorithm is proposed to reproduce a more accurate fading environment.Various standard channel models and setup configurations are comprehensively simulated to validate the capacity of the proposed methods.The simulation results show that more competent active probes are selected with the proposed method compared to the conventional algorithms.Furthermore,the derived closedform probe weighting strategy offers identical accuracy to that obtained with complicated numerical optimization.Moreover,a realistic dynamic channel measured in an indoor environment is reconstructed with the developed methodologies,and 95.6%PAS similarity can be achieved with 6 active probes.The satisfactory results demonstrate that the proposed algorithms are suitable for arbitrary channel emulation.展开更多
L1 is one of the largest offshore gas fields currently under development.In order to optimize the related design,nodal analysis is applied(including proper consideration of the plant productivity,sensitivity to the tu...L1 is one of the largest offshore gas fields currently under development.In order to optimize the related design,nodal analysis is applied(including proper consideration of the plant productivity,sensitivity to the tubing size,erosion effects,liquid carrying performance,and tubing string).As a result of such approach,it is shown that 13Cr material should be chosen as the appropriate tubing material.Moreover,3-1/2 inches 9.3 lb/ft N80 tubing,4-1/2 inches 12.75 lb/ft N80 tubing,5-1/2 inches 17 lb/ft N80 tubing should be used for a gas production rate under 80×10^(4)m^(3)/d,between 80×10^(4)m^(3)/d and 120×10^(4)m^(3)/d and above 120×10^(4)m^(3)/d,respectively.展开更多
Dear Editor,Uveal melanoma(UM)is the most common primary intraocular malignancy in adults[1].We are writing to present a case of recurrent UM.This case presents an important clinical challenge:vision preservation in p...Dear Editor,Uveal melanoma(UM)is the most common primary intraocular malignancy in adults[1].We are writing to present a case of recurrent UM.This case presents an important clinical challenge:vision preservation in patients with recurrent anterior UM,especially in young patients.Informed consent was obtained from the patient.This case study adhered to the tenets of the Declaration of Helsinki and was approved by the Institutional Review Board of Beijing Tongren Hospital(approval number:TRECKY2018-056).展开更多
Objective To investigate the influence of vitamin D receptor (VDR) gene polymorphisms on susceptibility to type 1 diabetes mellitus (T1DM) in the Chinese Han population. Method One hundred and thirty-six Chinese Han p...Objective To investigate the influence of vitamin D receptor (VDR) gene polymorphisms on susceptibility to type 1 diabetes mellitus (T1DM) in the Chinese Han population. Method One hundred and thirty-six Chinese Han people, including 54 T1DM patients and 82 unrelated healthy subjects as control were genotyped by polymerase chain reaction-restriction fragment length polymorphism for three restriction sites in the VDR gene, which were ApaI, TaqI, and BamI. Results The frequency of B allele of BsmI site in VDR gene was significantly higher in T1DM patients than in healthy subjects (P = 0.033) while no difference was found between the two groups in the distribution of ApaI and TaqI polymorphisms. Conclusion The BsmI polymorphism of VDR gene may be associated with the susceptibility to T1DM in the Chinese Han population of Beijing.展开更多
The chrysanthemum genome harbors three FT-like genes:CmFTL1 and CmFTL3 are thought to act as regulators of floral induction under long-day(LD)and short-day(SD)conditions,respectively,whereas the function of CmFTL2 is ...The chrysanthemum genome harbors three FT-like genes:CmFTL1 and CmFTL3 are thought to act as regulators of floral induction under long-day(LD)and short-day(SD)conditions,respectively,whereas the function of CmFTL2 is currently unclear.The objective of the present research was to explore the function of CmFTL2 in the determination of flowering time of the photo-insensitive chrysanthemum cultivar‘Floral Yuuka’,both in response to variation in the photoperiod and to the exogenous provision of sucrose.Spraying leaves of‘Floral Yuuka’plants with 50 mM sucrose accelerated flowering and increased the level of CmFTL2 transcription in the leaf more strongly than either CmFTL1 or FTL3 under both long and SD conditions.Transcription profiling indicated that all three CmFTL genes were upregulated during floral induction.The relationship of the CmFTL2 sequence with that of other members of the PEBP family suggested that its product contributes to the florigen rather than to the anti-florigen complex.The heterologous expression of CmFTL2 in the Arabidopsis thaliana ft-10 mutant rescued the mutant phenotype,showing that CmFTL2 could compensate for the absence of FT.These results suggest that CmFTL2 acts as a regulator of floral transition and responds to both the photoperiod and sucrose.展开更多
AIM: To study the role of luteolin(LUT) in the expression of toll-like receptors 3(TLR3) ligand poly I:C stimulated inflammatory factors in human corneal fibroblasts(HCFs).METHODS: HCFs cells were cultivated with or w...AIM: To study the role of luteolin(LUT) in the expression of toll-like receptors 3(TLR3) ligand poly I:C stimulated inflammatory factors in human corneal fibroblasts(HCFs).METHODS: HCFs cells were cultivated with or without LUT or poly I:C.The expression levels of interleukin(IL)-6, IL-8, monocyte chemotactic protein-1(MCP-1), vascular cell adhesion molecule(VCAM)-1, as well as intercellular adhesion molecule(ICAM)-1 were measured using enzymelinked immunosorbent assay(ELISA), immunoblotting or reverse transcription-quantitative polymerase chain reaction(PCR) analyses.Immunoblotting was used to assess toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-β(TRIF), TLR3, transforming growth factor-bactivated kinase 1(TAK1), tumor necrosis factor receptor-associated factor 6(TRAF6), the transcription factor AP-1, as well as transcription factor nuclear factor(NF-κB)–inhibitory protein IκB-α degradation and phosphorylation.Immunofluorescence assays were used to localize the cellular location of the p65 subunit of NF-κB.RESULTS: Corneal fibroblasts exposed to poly I:C demonstrated decreased VCAM-1, ICAM-1, MCP-1, IL-6, and IL-8 expression levels upon exposure to LUT in a time-dependent and concentration-dependent manner.LUT was observed to suppress poly I:C-triggered expression of TLR3, the translocation of NF-κB p65 into cell nuclei, as well as the phosphorylation of TAK, c-Jun, and IκB-α, while no impact on the expression levels of TRIF and TRAF6 were observed.CONCLUSION: LUT suppress the expression of proinflammatory adhesion molecules, chemokines, and cytokines in poly I:C exposed HCFs.These effects are likely mediated through TAK/NF-κB signal attenuation.Therefore, LUT is a candidate molecule that can prevent the TLR3-mediated inflammation response associated with corneal viral infection.展开更多
Natural and human-induced changes may exert considerable impacts on the seasonal and nodal dynamics of M2 and K1 tidal constituents.Therefore,quantifying the influences of these factors on tidal regime changes is esse...Natural and human-induced changes may exert considerable impacts on the seasonal and nodal dynamics of M2 and K1 tidal constituents.Therefore,quantifying the influences of these factors on tidal regime changes is essential for sustainable water resources management in coastal environments.In this study,the enhanced harmonic analysis was applied to extract the seasonal variability of the M2 and K1 tidal amplitudes and phases at three gauging stations along Lingdingyang Bay of the Zhujiang River Delta.The seasonal dynamics in terms of tidal wave celerity and amplification/damping rate were used to quantify the impacts of human-induced estuarine morphological alterations on M2 and K1 tidal hydrodynamics in inner and outer Lingdingyang Bay.The results show that both tidal amplification/damping rate and wave celerity were considerably increased from the pre-anthropogenic activity period(Pre-AAP)to the post-anthropogenic activity period(Post-AAP)excepting the tidal amplification/damping rate in outer Lingdingyang Bay,and the variations in outer Lingdingyang Bay was larger than those in inner Lingdingyang Bay.The alterations in these two parameters were more significant in flood season than in dry season in both inner and outer Lingdingyang Bay.The seasonal variability of M2 and K1 tidal amplitudes were further quantified using a regression model accounting for the 18.61-year lunar nodal modulation,where this study observes a considerable alteration in M2 constituent owing to human interventions.During the Post-AAP,the M2 amplitudes at the downstream station were larger than those that would have occurred in the absence of strong human interventions,whereas the opposite was true for the upstream station,leading to a substantial decrease in tidal amplification in outer Lingdingyang Bay.However,it is opposite in inner Lingdingyang Bay.The underlying mechanism can be primarily attributed to channel deepening and narrowing caused by human interventions,that resulted in substantial enlargement of the bay volume and reduced the effective bottom friction,leading to faster wave celerity and stronger amplified waves.展开更多
Command, control, communication, computing, intelligence, surveillance and reconnaissance(C4ISR) in information age is a complex system whose structure always changes actively or passively during the warfare. Therefor...Command, control, communication, computing, intelligence, surveillance and reconnaissance(C4ISR) in information age is a complex system whose structure always changes actively or passively during the warfare. Therefore, it is important to optimize the structure, especially in ambiguous and quick-tempo modern warfare. This paper proposes an adaptive evolvement mechanism for the C4ISR structure to survive the changeable warfare. Firstly, the information age C4ISR structure is defined and modeled based on the complex network theory. Secondly,taking the observe, orient, decide and act(OODA) model into consideration, four kinds of loops in the C4ISR structure are proposed and their coefficient of networked effects(CNE) is further defined. Then, the adaptive evolvement mechanisms of the four kinds of loops are presented respectively. Finally, taking the joint air-defense C4ISR as an example, simulation experiments are implemented, which validate the evolvement mechanism and show that the information age C4ISR structure has some characteristics of small-world network and scale-free network.展开更多
Salamanders are unique among tetrapods in their ability to regenerate the limbs throughout life.Like other poikilothermic amphibians,salamanders also show a remarkable capacity to survive long periods of starvation.Wh...Salamanders are unique among tetrapods in their ability to regenerate the limbs throughout life.Like other poikilothermic amphibians,salamanders also show a remarkable capacity to survive long periods of starvation.Whether the physiological reserves necessary for tissue regeneration are preserved or sacrificed in starved salamanders is unknown.In the current study,we maintained Iberian ribbed newts(Pleurodeles waltl)under extreme physiological stress to assess the extent of regeneration and identify the molecular and cellular changes that may occur under such conditions.After 19 months of complete food deprivation,the animals exhibited extensive morphological and physiological adaptations but remained behaviorally active and vigilant.Autophagy was elevated in different tissues and the transformed gut microbiota indicated remodeling of the intestinal tract related to autophagy.Upon limb amputation in animals starved for 21 months,regeneration proceeded with progenitor cell proliferation and migration,leading to limb blastema formation.However,limb outgrowth and patterning were substantially attenuated.Blockage of autophagy inhibited cell proliferation and blastema formation in starved animals,but not in fed animals.Hence,tissue autophagy and the regenerative response were tightly coupled only when animals were under stress.Our results demonstrate that under adverse conditions,salamanders can exploit alternative strategies to secure blastema formation for limb regeneration.展开更多
文摘In this paper, the problem of abnormal spectrum usage between satellite spectrum sharing systems is investigated to support multi-satellite spectrum coexistence. Given the cost of monitoring, the mobility of low-orbit satellites, and the directional nature of their signals, traditional monitoring methods are no longer suitable, especially in the case of multiple power level. Mobile crowdsensing(MCS), as a new technology, can make full use of idle resources to complete a variety of perceptual tasks. However, traditional MCS heavily relies on a centralized server and is vulnerable to single point of failure attacks. Therefore, we replace the original centralized server with a blockchain-based distributed service provider to enable its security. Therefore, in this work, we propose a blockchain-based MCS framework, in which we explain in detail how this framework can achieve abnormal frequency behavior monitoring in an inter-satellite spectrum sharing system. Then, under certain false alarm probability, we propose an abnormal spectrum detection algorithm based on mixed hypothesis test to maximize detection probability in single power level and multiple power level scenarios, respectively. Finally, a Bad out of Good(BooG) detector is proposed to ease the computational pressure on the blockchain nodes. Simulation results show the effectiveness of the proposed framework.
基金Supported by the National Natural Science Foundation of China(No.81770889)Zhuhai Science and Technology Program(No.ZH22036201210134PWC).
文摘●AIM:To evaluate the role of semaphorin 7A(Sema7A)and its associated regulatory mechanisms in modulating the barrier function of cultured human corneal epithelial cells(HCEs).●METHODS:Barrier models of HCEs were treated with recombinant human Sema7A at concentrations of 0,125,250,or 500 ng/mL for 24,48,or 72h in vitro.Transepithelial electrical resistance(TEER)as well as Dextran-fluorescein isothiocyanate(FITC)permeability assays were conducted to assess barrier function.To quantify tight junctions(TJs)such as occludin and zonula occludens-1(ZO-1)at the mRNA level,reverse transcriptionpolymerase chain reaction(RT-PCR)analysis was performed.Immunoblotting was used to examine the activity of the nuclear factor-kappa B(NF-κB)signaling pathway and the production of TJs proteins.Immunofluorescence analyses were employed to localize the TJs.Enzyme-linked immunosorbent assay(ELISA)and RT-PCR were utilized to observe changes in interleukin(IL)-1βlevels.To investigate the role of NF-κB signaling activation and IL^(-1)βin Sema7A’s anti-barrier mechanism,we employed 0.1μmol/L IκB kinase 2(IKK2)inhibitor IV or 500 ng/mL IL^(-1)receptor(IL-1R)antagonist.●RESULTS:Treatment with Sema7A resulted in decreased TEER and increased permeability of Dextran-FITC in HCEs through down-regulating mRNA and protein levels of TJs in a time-and dose-dependent manner,as well as altering the localization of TJs.Furthermore,Sema7A stimulated the activation of inhibitor of kappa B alpha(IκBα)and expression of IL-1β.The anti-barrier function of Sema7A was significantly suppressed by treatment with IKK2 inhibitor IV or IL-1R antagonists.●CONCLUSION:Sema7A disrupts barrier function through its influence on NF-κB-mediated expression of TJ proteins,as well as the expression of IL-1β.These findings suggest that Sema7A could be a potential therapeutic target for the diseases in corneal epithelium.
基金supported by grants from the National Natural Science Foundation of China(No.81873694)the Key Research and Development Program of Hubei Province(No.2021BCA119 and No.2022BCA005)Knowledge Innovation Program of Wuhan-Basic Research(No.2022020801010446).
文摘Objective To identify factors affecting the efficacy of steroid-eluting sinus stents implanted after endoscopic sinus surgery(ESS)in patients with chronic rhinosinusitis with nasal polyps(CRSwNP).Methods We performed a post-hoc analysis of a randomized self-controlled clinical trial on post-operative implantation of bioabsorbable steroid-eluting stents in patients with CRSwNP.Univariate logistic regression analysis was conducted to identify which of the following factors affect the response to post-operative stent implantation:sex,serum eosinophil levels,history of prior surgery,endoscopic scores,and comorbid conditions(asthma and allergic rhinitis).The primary outcome was the rate of post-operative intervention on day 30,and the secondary outcome was the rate of polypoid tissue formation(grades 2–3)on days 14,30,and 90.Results A total of 151 patients with CRSwNP were included in the post-hoc analysis.Asthma was identified as the only risk factor for a poor response to steroid-eluting sinus stents on post-operative day 30,with an odds ratio of 23.71(95%CI,2.81,200.16;P=0.004)for the need for post-operative intervention and 19(95%CI,2.20,164.16;P=0.003)for moderate-to-severe polypoid tissue formation.In addition,the asthmatic group showed higher rates of post-operative intervention and polypoid tissue formation than the non-asthmatic group on post-operative day 30.Blood eosinophil levels were not identified as a risk factor for poor outcomes after stent implantation.Conclusion Comorbid asthma,but not blood eosinophil level,impairs the efficacy of steroid-eluting sinus stents in the short term after ESS in patients with CRSwNP.
基金supported by the Henan medical science and technology research projects(222102310014)
文摘Purpose:To evaluate the feasibility and efficacy of a transmesenteric vein extrahepatic portosystemic shunt(TmEPS)for the treatment of cavernous transformation of the portal vein(CTPV).Materials and methods:The clinical data of 20 patients with CTPV who underwent TmEPS between December 2020and January 2022 at Henan Provincial People’s Hospital were retrospectively collected.The superior mesenteric vein(SMV)trunk was patent or partially occluded in these patients.An extrahepatic portosystemic shunt between the inferior vena cava and the SMV was established using a stent graft through an infraumbilical median longitudinal mini-laparotomy.The technical success,efficacy,and complication rates were evaluated,and the preand postoperative SMV pressures were compared.Patients’clinical outcomes and shunt patency were assessed.Results:TmEPS was successfully performed in 20 patients.The initial puncture success rate of the balloon-assisted puncture technique is 95%.The mean SMV pressure decreased from 29.1±2.9 mmHg to 15.6±3.3 mmHg(p<0.001).All symptoms of portal hypertension resolved.No fatal procedural complications occurred.During the follow-up period,hepatic encephalopathy occurred in two patients.The remaining patients remained asymptomatic.All shunts were patent.Conclusions:TmEPS is a feasible,safe,and effective treatment option for patients with CTPV.
基金supported by the National Natural Science Foundation of China(62173029,62273033,U20A20225)the Fundamental Research Funds for the Central Universities,China(FRF-BD-19-002A)。
文摘This paper investigates the problem of path tracking control for autonomous ground vehicles(AGVs),where the input saturation,system nonlinearities and uncertainties are considered.Firstly,the nonlinear path tracking system is formulated as a linear parameter varying(LPV)model where the variation of vehicle velocity is taken into account.Secondly,considering the noise effects on the measurement of lateral offset and heading angle,an observer-based control strategy is proposed,and by analyzing the frequency domain characteristics of the derivative of desired heading angle,a finite frequency H_∞index is proposed to attenuate the effects of the derivative of desired heading angle on path tracking error.Thirdly,sufficient conditions are derived to guarantee robust H_∞performance of the path tracking system,and the calculation of observer and controller gains is converted into solving a convex optimization problem.Finally,simulation examples verify the advantages of the control method proposed in this paper.
基金supported by National Natural Science Foundation of China(No.62090015,No.61821001)BUPT Excellent Ph.D.Students Foundation under Grant(CX2021216)。
文摘In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at beamforming mode,which requires a realistic non-stationary channel environment.For the dynamic propagation emulation,an efficient closed-form probe weighting strategy minimizing the power angular spectrum(PAS)emulation errors is derived,substantially reducing the associated computational complexity.On the other hand,a novel probe selection algorithm is proposed to reproduce a more accurate fading environment.Various standard channel models and setup configurations are comprehensively simulated to validate the capacity of the proposed methods.The simulation results show that more competent active probes are selected with the proposed method compared to the conventional algorithms.Furthermore,the derived closedform probe weighting strategy offers identical accuracy to that obtained with complicated numerical optimization.Moreover,a realistic dynamic channel measured in an indoor environment is reconstructed with the developed methodologies,and 95.6%PAS similarity can be achieved with 6 active probes.The satisfactory results demonstrate that the proposed algorithms are suitable for arbitrary channel emulation.
基金supported by the National Natural Science Foundation of China(Grant No.52174015)the Scientific Research Project of CNOOC(China)Co.,Ltd.“Research on key technologies for drilling and completion of 20 million cubic meters in Western Nanhai Oilfield”(No.CNOOC-KJ135ZDXM38ZJ05ZJ).
文摘L1 is one of the largest offshore gas fields currently under development.In order to optimize the related design,nodal analysis is applied(including proper consideration of the plant productivity,sensitivity to the tubing size,erosion effects,liquid carrying performance,and tubing string).As a result of such approach,it is shown that 13Cr material should be chosen as the appropriate tubing material.Moreover,3-1/2 inches 9.3 lb/ft N80 tubing,4-1/2 inches 12.75 lb/ft N80 tubing,5-1/2 inches 17 lb/ft N80 tubing should be used for a gas production rate under 80×10^(4)m^(3)/d,between 80×10^(4)m^(3)/d and 120×10^(4)m^(3)/d and above 120×10^(4)m^(3)/d,respectively.
基金Supported by National Natural Science Foundation of China(No.82141128)the Capital Health Research and Development of Special(No.2020-1-2052)+4 种基金Beijing Natural Science Foundation(No.7204245)Science&Technology Project of Beijing Municipal Science&Technology Commission(No.Z201100005520045,No.Z181100001818003)Scientific Research Common Program of Beijing Municipal Commission of Education(No.KM202010025018)Beijing Municipal Administration of Hospitals’Youth Programme(No.QML20190202)Beijing Dongcheng District Outstanding Talents Cultivating Plan(No.2018).
文摘Dear Editor,Uveal melanoma(UM)is the most common primary intraocular malignancy in adults[1].We are writing to present a case of recurrent UM.This case presents an important clinical challenge:vision preservation in patients with recurrent anterior UM,especially in young patients.Informed consent was obtained from the patient.This case study adhered to the tenets of the Declaration of Helsinki and was approved by the Institutional Review Board of Beijing Tongren Hospital(approval number:TRECKY2018-056).
基金supported by the National Natural Science Foundation of China (21771070, 21571071)the Fundamental Research Funds for the Central Universities (2018KFYYXJJ120, 2019KFYRCPY104)~~
文摘Objective To investigate the influence of vitamin D receptor (VDR) gene polymorphisms on susceptibility to type 1 diabetes mellitus (T1DM) in the Chinese Han population. Method One hundred and thirty-six Chinese Han people, including 54 T1DM patients and 82 unrelated healthy subjects as control were genotyped by polymerase chain reaction-restriction fragment length polymorphism for three restriction sites in the VDR gene, which were ApaI, TaqI, and BamI. Results The frequency of B allele of BsmI site in VDR gene was significantly higher in T1DM patients than in healthy subjects (P = 0.033) while no difference was found between the two groups in the distribution of ApaI and TaqI polymorphisms. Conclusion The BsmI polymorphism of VDR gene may be associated with the susceptibility to T1DM in the Chinese Han population of Beijing.
基金This work was supported by funding from the National Natural Science Foundation of China(31372100)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsby‘Programs of Innovation and Entrepreneurship Talents’of Jiangsu Province.
文摘The chrysanthemum genome harbors three FT-like genes:CmFTL1 and CmFTL3 are thought to act as regulators of floral induction under long-day(LD)and short-day(SD)conditions,respectively,whereas the function of CmFTL2 is currently unclear.The objective of the present research was to explore the function of CmFTL2 in the determination of flowering time of the photo-insensitive chrysanthemum cultivar‘Floral Yuuka’,both in response to variation in the photoperiod and to the exogenous provision of sucrose.Spraying leaves of‘Floral Yuuka’plants with 50 mM sucrose accelerated flowering and increased the level of CmFTL2 transcription in the leaf more strongly than either CmFTL1 or FTL3 under both long and SD conditions.Transcription profiling indicated that all three CmFTL genes were upregulated during floral induction.The relationship of the CmFTL2 sequence with that of other members of the PEBP family suggested that its product contributes to the florigen rather than to the anti-florigen complex.The heterologous expression of CmFTL2 in the Arabidopsis thaliana ft-10 mutant rescued the mutant phenotype,showing that CmFTL2 could compensate for the absence of FT.These results suggest that CmFTL2 acts as a regulator of floral transition and responds to both the photoperiod and sucrose.
基金Supported by the National Natural Science Foundation of China (No.81770889)Administration of Traditional Chinese Medicine of Guangdong Province (No.20201070)。
文摘AIM: To study the role of luteolin(LUT) in the expression of toll-like receptors 3(TLR3) ligand poly I:C stimulated inflammatory factors in human corneal fibroblasts(HCFs).METHODS: HCFs cells were cultivated with or without LUT or poly I:C.The expression levels of interleukin(IL)-6, IL-8, monocyte chemotactic protein-1(MCP-1), vascular cell adhesion molecule(VCAM)-1, as well as intercellular adhesion molecule(ICAM)-1 were measured using enzymelinked immunosorbent assay(ELISA), immunoblotting or reverse transcription-quantitative polymerase chain reaction(PCR) analyses.Immunoblotting was used to assess toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-β(TRIF), TLR3, transforming growth factor-bactivated kinase 1(TAK1), tumor necrosis factor receptor-associated factor 6(TRAF6), the transcription factor AP-1, as well as transcription factor nuclear factor(NF-κB)–inhibitory protein IκB-α degradation and phosphorylation.Immunofluorescence assays were used to localize the cellular location of the p65 subunit of NF-κB.RESULTS: Corneal fibroblasts exposed to poly I:C demonstrated decreased VCAM-1, ICAM-1, MCP-1, IL-6, and IL-8 expression levels upon exposure to LUT in a time-dependent and concentration-dependent manner.LUT was observed to suppress poly I:C-triggered expression of TLR3, the translocation of NF-κB p65 into cell nuclei, as well as the phosphorylation of TAK, c-Jun, and IκB-α, while no impact on the expression levels of TRIF and TRAF6 were observed.CONCLUSION: LUT suppress the expression of proinflammatory adhesion molecules, chemokines, and cytokines in poly I:C exposed HCFs.These effects are likely mediated through TAK/NF-κB signal attenuation.Therefore, LUT is a candidate molecule that can prevent the TLR3-mediated inflammation response associated with corneal viral infection.
基金The National Key R&D Program of China under contract No.2016YFC0402600the National Natural Science Foundation of China under contract No.51979296the Guangzhou Science and Technology Program of China under contract No.202002030452。
文摘Natural and human-induced changes may exert considerable impacts on the seasonal and nodal dynamics of M2 and K1 tidal constituents.Therefore,quantifying the influences of these factors on tidal regime changes is essential for sustainable water resources management in coastal environments.In this study,the enhanced harmonic analysis was applied to extract the seasonal variability of the M2 and K1 tidal amplitudes and phases at three gauging stations along Lingdingyang Bay of the Zhujiang River Delta.The seasonal dynamics in terms of tidal wave celerity and amplification/damping rate were used to quantify the impacts of human-induced estuarine morphological alterations on M2 and K1 tidal hydrodynamics in inner and outer Lingdingyang Bay.The results show that both tidal amplification/damping rate and wave celerity were considerably increased from the pre-anthropogenic activity period(Pre-AAP)to the post-anthropogenic activity period(Post-AAP)excepting the tidal amplification/damping rate in outer Lingdingyang Bay,and the variations in outer Lingdingyang Bay was larger than those in inner Lingdingyang Bay.The alterations in these two parameters were more significant in flood season than in dry season in both inner and outer Lingdingyang Bay.The seasonal variability of M2 and K1 tidal amplitudes were further quantified using a regression model accounting for the 18.61-year lunar nodal modulation,where this study observes a considerable alteration in M2 constituent owing to human interventions.During the Post-AAP,the M2 amplitudes at the downstream station were larger than those that would have occurred in the absence of strong human interventions,whereas the opposite was true for the upstream station,leading to a substantial decrease in tidal amplification in outer Lingdingyang Bay.However,it is opposite in inner Lingdingyang Bay.The underlying mechanism can be primarily attributed to channel deepening and narrowing caused by human interventions,that resulted in substantial enlargement of the bay volume and reduced the effective bottom friction,leading to faster wave celerity and stronger amplified waves.
基金supported by the National Defense Basic Research Program of China and National Defense Pre-Research Foundation of China
文摘Command, control, communication, computing, intelligence, surveillance and reconnaissance(C4ISR) in information age is a complex system whose structure always changes actively or passively during the warfare. Therefore, it is important to optimize the structure, especially in ambiguous and quick-tempo modern warfare. This paper proposes an adaptive evolvement mechanism for the C4ISR structure to survive the changeable warfare. Firstly, the information age C4ISR structure is defined and modeled based on the complex network theory. Secondly,taking the observe, orient, decide and act(OODA) model into consideration, four kinds of loops in the C4ISR structure are proposed and their coefficient of networked effects(CNE) is further defined. Then, the adaptive evolvement mechanisms of the four kinds of loops are presented respectively. Finally, taking the joint air-defense C4ISR as an example, simulation experiments are implemented, which validate the evolvement mechanism and show that the information age C4ISR structure has some characteristics of small-world network and scale-free network.
基金This study was supported by the National Natural Science Foundation of China(31771617)and HZAU-AGIS Cooperation Fund(SZYJY2021009)。
文摘Salamanders are unique among tetrapods in their ability to regenerate the limbs throughout life.Like other poikilothermic amphibians,salamanders also show a remarkable capacity to survive long periods of starvation.Whether the physiological reserves necessary for tissue regeneration are preserved or sacrificed in starved salamanders is unknown.In the current study,we maintained Iberian ribbed newts(Pleurodeles waltl)under extreme physiological stress to assess the extent of regeneration and identify the molecular and cellular changes that may occur under such conditions.After 19 months of complete food deprivation,the animals exhibited extensive morphological and physiological adaptations but remained behaviorally active and vigilant.Autophagy was elevated in different tissues and the transformed gut microbiota indicated remodeling of the intestinal tract related to autophagy.Upon limb amputation in animals starved for 21 months,regeneration proceeded with progenitor cell proliferation and migration,leading to limb blastema formation.However,limb outgrowth and patterning were substantially attenuated.Blockage of autophagy inhibited cell proliferation and blastema formation in starved animals,but not in fed animals.Hence,tissue autophagy and the regenerative response were tightly coupled only when animals were under stress.Our results demonstrate that under adverse conditions,salamanders can exploit alternative strategies to secure blastema formation for limb regeneration.
