L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正...L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。展开更多
针对L波段数字航空通信系统(L-band digital aeronautic communication system,LDACS)可用频谱资源有限且易受大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出一种基于降维循环谱和残差神经网络的频谱感知方法。首...针对L波段数字航空通信系统(L-band digital aeronautic communication system,LDACS)可用频谱资源有限且易受大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出一种基于降维循环谱和残差神经网络的频谱感知方法。首先理论推导分析了DME信号的循环谱特征;然后利用Fisher判别率(Fisher discriminant rate,FDR)提取循环频率能量最大的向量,通过主成分分析(principal component analysis,PCA)进行预处理特征增强;最后给出数据处理后的循环谱向量与卷积神经网络相结合的实现过程,实现了DME信号的有效检测。仿真结果表明,该方法对噪声不敏感,当信噪比不低于-15 dB时,平均检测概率大于90%。当信噪比不低于-14 dB,检测概率接近100%。展开更多
This work analyzes the photometric data of the Oort spike comets C/2019 L3(ATLAS)and C/2019 O3(Palomar)obtained between 2016 and 2023 by the ATLAS network and the Belgian Olmen Observatory.The comets Palomar and ATLAS...This work analyzes the photometric data of the Oort spike comets C/2019 L3(ATLAS)and C/2019 O3(Palomar)obtained between 2016 and 2023 by the ATLAS network and the Belgian Olmen Observatory.The comets Palomar and ATLAS have a typical and unusually high activity level,respectively,based on the Afρparameter corrected to phase angle zero at perihelion.The absolute magnitude of comets ATLAS and Palomar in the o-band is 4.71±0.05 and 4.16±0.02 respectively.The cometary activity of comets ATLAS and Palomar probably began at r>13 au before perihelion and will end at r>14 au after perihelion,which means that they could remain active until the second half of 2026.The nucleus of comet ATLAS has a minimum radius of 7.9 km,and the nucleus of comet Palomar could be a little larger.The c-o colors of the comets ATLAS and Palomar are redder and bluer,respectively,at perihelion than the solar twin YBP 1194.These comets showed a bluish trend in the coma color with decreasing heliocentric distance.Comet Palomar probably had two outbursts after its perihelion,each releasing about 10^(8)kg of dust.The slopes of the photometric profile of the comae of these comets were between 1and 1.5,indicating a steady state during the observation campaign.展开更多
In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries fa...In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. This challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the Taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. The Taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. The proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. Three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the Taguchi analysis. The results revealed that the Taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. This indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. The identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17 W during charging were designed and simulated in the range of 0-12000 s using COMSOL Multiphysics software. This study efficiently employs the Taguchi optimization technique to develop lithium-ion batteries capable of storing a predetermined average electric power during the charging phase. Therefore, this method enables the battery to achieve complete charging within a specific timeframe tailored to a specificapplication. The implementation of this method can save costs, time, and materials compared with other alternative methods, such as the trial-and-error approach.展开更多
A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidat...A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidation determined the planar structure of 1.Subsequent electronic circular dichroism(ECD)experiment assigned the absolute configuration of 1.Compounds 1,2,4–6,and 10 displayed different degrees of neuroprotective activities on human neuroblastoma cells SH-SY5Y.Five compounds(1,3–5,and 13)emerged resistance to protein tyrosine phosphatase 1B(PTP1B),further kinetic analysis and molecular docking study indicated that the most potent compound 13(IC50value of 10.74±0.61μmol/L)was found as a noncompetitive inhibitor for PTP1B.Surface plasmon resonance(SPR)and molecular docking studies also demonstrated the interaction between compound 12 and Niemann-Pick C1 Like 1(NPC1L1),which has been identified as significant therapeutic target for hypercholesteremia.In addition,compounds 3,6,and 14 showed attractive inhibitory activity against the phytopathogenic fungi:Colletotrichum capsici.Therefore,library of Cladosporium metabolites is enriched and new active uses of known compounds are explored.展开更多
BACKGROUND The TGF-β/SMAD3 and VEGFR-1 signaling pathways play important roles in gastric cancer metastasis.SMAD3 phosphorylation is a crucial prognostic marker in gastric cancer.AIM To determine the prognostic value...BACKGROUND The TGF-β/SMAD3 and VEGFR-1 signaling pathways play important roles in gastric cancer metastasis.SMAD3 phosphorylation is a crucial prognostic marker in gastric cancer.AIM To determine the prognostic value and relationship of SMAD3 phospho-isoforms and VEGFR-1 in gastric cancer.METHODS This was a single-center observational study which enrolled 98 gastric cancer patients and 82 adjacent normal gastric tissues from patients aged 32-84 years(median age 65)between July 2006 and April 2007.Patients were followed up until death or the study ended(median follow-up duration of 28.5 mo).The samples were used to generate tissue microarrays(TMAs)for immunohistochemical(IHC)staining.The expressions of TGF-β1,pSMAD3C(S423/425),pSMAD3L(S204),and VEGFR-1 in gastric cancer(GC)tumor tissue and normal tissue were measured by IHC staining using TMAs obtained from 98 GC patients.Prognosis and survival information of the patients was recorded by Outdo Biotech from May 2007 to July 2015.The relationship between TGF-β1,pSMAD3C(S423/425),pSMAD3L(S204),and VEGFR-1 protein expression levels was analyzed using Pearson's correlation coefficient.The relationship between protein expression levels and clinicopathological parameters was analyzed using the Chi-squared test.A survival curve was generated using the Kaplan-Meier survival analysis.RESULTS TGFβ-1 and VEGFR-1 expression was significantly upregulated in gastric cancer tissue compared to adjacent noncancerous tissue.The positive expression of phosphorylated isoforms of Smad3 varied depending on the phosphorylation site[pSMAD3C(S423/425):51.0%and pSMAD3L(S204):31.6%].High expression of pSMAD-3L(S204)was significantly correlated with larger tumors(P=0.038)and later N stages(P=0.035).Additionally,high expression of VEGFR-1 was closely correlated with tumor size(P=0.015)and pathological grading(P=0.013).High expression of both pSMAD3L(S204)and VEGFR-1 was associated with unfavorable outcomes in terms of overall survival(OS).Multivariate analysis indicated that high expression of pSMAD3L(S204)and VEGFR-1 were independent risk factors for prognosis in GC patients.VEGFR-1 protein expression was correlated with TGF-β1(r=0.220,P=0.029),pSMAD3C(S423/425)(r=0.302,P=0.002),and pSMAD3L(S204)(r=0.201,P=0.047),respectively.Simultaneous overexpression of pSMAD3L(S204)and VEGFR-1 was associated with poor OS in gastric cancer patients.CONCLUSION Co-upregulation of pSMAD3L(S204)and VEGFR-1 can serve as a predictive marker for poor gastric cancer prognosis,and pSMAD3L(204)may be involved in enhanced gastric cancer metastasis in a VEGFR-1-dependent manner.展开更多
A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a...A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a coastal location and to characterize their properties and behaviors. Primary and secondary field observation methods were utilized in this data-centric study. Forensic engineering principles and methodologies guided the study. The challenges set forward were object detection, observation, and characterization, where multispectral electro-optical devices and radar were employed due to limited visual acuity and intermittent presentation of the phenomena. The primary means of detection utilized a 3 cm X-band radar operating in two scan geometries, the X- and Y-axis. Multispectral electro-optical devices were utilized as a secondary means of detection and identification. Data was emphasized using HF and LF detectors and spectrum analyzers incorporating EM, ultrasonic, magnetic, and RF field transducers to record spectral data in these domains. Data collection concentrated on characterizing VIS, NIR, SWIR, LWIR, UVA, UVB, UVC, and the higher energy spectral range of ionizing radiation (alpha, beta, gamma, and X-ray) recorded by Geiger-Müller counters as well as special purpose semiconductor diode sensors.展开更多
目的探讨血清肌酐/半胱氨酸蛋白酶抑制剂C(sCr/CysC)比值对胰腺癌早期诊断和预后评估的价值。方法回顾性分析苏州大学附属第一医院2020年1月至2021年12月收治的60例初诊胰腺癌患者、30例胰腺良性肿瘤患者和30例健康对照者的临床资料。...目的探讨血清肌酐/半胱氨酸蛋白酶抑制剂C(sCr/CysC)比值对胰腺癌早期诊断和预后评估的价值。方法回顾性分析苏州大学附属第一医院2020年1月至2021年12月收治的60例初诊胰腺癌患者、30例胰腺良性肿瘤患者和30例健康对照者的临床资料。比较三组间sCr/CysC比值、C反应蛋白(CRP)、L3骨骼肌指数(L3-SMI)、Alb和CA199水平的差异。采用ROC曲线分析sCr/CysC比值对胰腺癌的诊断效能。根据sCr/CysC比值中位数将胰腺癌患者分为高比值组和低比值组,应用Kaplan-Meier生存曲线和Cox回归模型分析sCr/CysC比值对胰腺癌预后的预测价值。结果与胰腺良性肿瘤组和健康对照组相比,胰腺癌组的sCr/CysC比值和Alb水平显著降低,而CRP水平明显升高(均P<0.05)。与低sCr/CysC比值组相比,高比值组患者的性别构成、年龄和L3 SMI水平差异有统计学意义(均P<0.05)。sCr/CysC比值对胰腺癌的诊断ROC曲线下面积为0.640(95%CI:0.524~0.756,P<0.05),在cut-off值为0.69时敏感性为46.7%,特异性为83.3%。相关分析显示,sCr/CysC比值与L3-SMI呈正相关(r=0.425,P<0.01)。生存分析表明,高sCr/CysC比值组患者的中位生存期显著长于低比值组(379 d vs 210 d,P<0.01)。Cox回归分析确认sCr/CysC比值是胰腺癌预后的独立危险因素(HR=0.151,95%CI:0.028~0.826,P<0.05)。结论sCr/CysC比值可能是胰腺癌早期诊断和预后评估的有效指标,有望为胰腺癌的临床诊疗提供参考。展开更多
文摘L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。
基金The ATLAS project is primarily funded to search for near-earth asteroids through NASA grants NN12AR55G,80NSSC18K0284,and 80NSSC18K1575funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889,and STFC grants ST/T000198/1 and ST/S006109/1。
文摘This work analyzes the photometric data of the Oort spike comets C/2019 L3(ATLAS)and C/2019 O3(Palomar)obtained between 2016 and 2023 by the ATLAS network and the Belgian Olmen Observatory.The comets Palomar and ATLAS have a typical and unusually high activity level,respectively,based on the Afρparameter corrected to phase angle zero at perihelion.The absolute magnitude of comets ATLAS and Palomar in the o-band is 4.71±0.05 and 4.16±0.02 respectively.The cometary activity of comets ATLAS and Palomar probably began at r>13 au before perihelion and will end at r>14 au after perihelion,which means that they could remain active until the second half of 2026.The nucleus of comet ATLAS has a minimum radius of 7.9 km,and the nucleus of comet Palomar could be a little larger.The c-o colors of the comets ATLAS and Palomar are redder and bluer,respectively,at perihelion than the solar twin YBP 1194.These comets showed a bluish trend in the coma color with decreasing heliocentric distance.Comet Palomar probably had two outbursts after its perihelion,each releasing about 10^(8)kg of dust.The slopes of the photometric profile of the comae of these comets were between 1and 1.5,indicating a steady state during the observation campaign.
文摘In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. This challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the Taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. The Taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. The proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. Three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the Taguchi analysis. The results revealed that the Taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. This indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. The identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17 W during charging were designed and simulated in the range of 0-12000 s using COMSOL Multiphysics software. This study efficiently employs the Taguchi optimization technique to develop lithium-ion batteries capable of storing a predetermined average electric power during the charging phase. Therefore, this method enables the battery to achieve complete charging within a specific timeframe tailored to a specificapplication. The implementation of this method can save costs, time, and materials compared with other alternative methods, such as the trial-and-error approach.
基金Supported by the China Agriculture Research System of MOF and MARA(CARS-21)the Financial Fund of the Ministry of Agriculture and Rural Affairs,China(No.NFZX2021)the National Natural Science Foundation of China(No.81973568)。
文摘A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidation determined the planar structure of 1.Subsequent electronic circular dichroism(ECD)experiment assigned the absolute configuration of 1.Compounds 1,2,4–6,and 10 displayed different degrees of neuroprotective activities on human neuroblastoma cells SH-SY5Y.Five compounds(1,3–5,and 13)emerged resistance to protein tyrosine phosphatase 1B(PTP1B),further kinetic analysis and molecular docking study indicated that the most potent compound 13(IC50value of 10.74±0.61μmol/L)was found as a noncompetitive inhibitor for PTP1B.Surface plasmon resonance(SPR)and molecular docking studies also demonstrated the interaction between compound 12 and Niemann-Pick C1 Like 1(NPC1L1),which has been identified as significant therapeutic target for hypercholesteremia.In addition,compounds 3,6,and 14 showed attractive inhibitory activity against the phytopathogenic fungi:Colletotrichum capsici.Therefore,library of Cladosporium metabolites is enriched and new active uses of known compounds are explored.
基金Supported by National Nature Science Foundation of China,No.82060450,No.82360517,No.81460374,and No.31460304Nature Science Foundation of Jiangxi Province of China,No.20232BAB206086,No.20192BAB205072,No.20203BBGL73206,No.2017BCB23086,No.2017BAB205062,and No.20181BAB205050.
文摘BACKGROUND The TGF-β/SMAD3 and VEGFR-1 signaling pathways play important roles in gastric cancer metastasis.SMAD3 phosphorylation is a crucial prognostic marker in gastric cancer.AIM To determine the prognostic value and relationship of SMAD3 phospho-isoforms and VEGFR-1 in gastric cancer.METHODS This was a single-center observational study which enrolled 98 gastric cancer patients and 82 adjacent normal gastric tissues from patients aged 32-84 years(median age 65)between July 2006 and April 2007.Patients were followed up until death or the study ended(median follow-up duration of 28.5 mo).The samples were used to generate tissue microarrays(TMAs)for immunohistochemical(IHC)staining.The expressions of TGF-β1,pSMAD3C(S423/425),pSMAD3L(S204),and VEGFR-1 in gastric cancer(GC)tumor tissue and normal tissue were measured by IHC staining using TMAs obtained from 98 GC patients.Prognosis and survival information of the patients was recorded by Outdo Biotech from May 2007 to July 2015.The relationship between TGF-β1,pSMAD3C(S423/425),pSMAD3L(S204),and VEGFR-1 protein expression levels was analyzed using Pearson's correlation coefficient.The relationship between protein expression levels and clinicopathological parameters was analyzed using the Chi-squared test.A survival curve was generated using the Kaplan-Meier survival analysis.RESULTS TGFβ-1 and VEGFR-1 expression was significantly upregulated in gastric cancer tissue compared to adjacent noncancerous tissue.The positive expression of phosphorylated isoforms of Smad3 varied depending on the phosphorylation site[pSMAD3C(S423/425):51.0%and pSMAD3L(S204):31.6%].High expression of pSMAD-3L(S204)was significantly correlated with larger tumors(P=0.038)and later N stages(P=0.035).Additionally,high expression of VEGFR-1 was closely correlated with tumor size(P=0.015)and pathological grading(P=0.013).High expression of both pSMAD3L(S204)and VEGFR-1 was associated with unfavorable outcomes in terms of overall survival(OS).Multivariate analysis indicated that high expression of pSMAD3L(S204)and VEGFR-1 were independent risk factors for prognosis in GC patients.VEGFR-1 protein expression was correlated with TGF-β1(r=0.220,P=0.029),pSMAD3C(S423/425)(r=0.302,P=0.002),and pSMAD3L(S204)(r=0.201,P=0.047),respectively.Simultaneous overexpression of pSMAD3L(S204)and VEGFR-1 was associated with poor OS in gastric cancer patients.CONCLUSION Co-upregulation of pSMAD3L(S204)and VEGFR-1 can serve as a predictive marker for poor gastric cancer prognosis,and pSMAD3L(204)may be involved in enhanced gastric cancer metastasis in a VEGFR-1-dependent manner.
文摘A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a coastal location and to characterize their properties and behaviors. Primary and secondary field observation methods were utilized in this data-centric study. Forensic engineering principles and methodologies guided the study. The challenges set forward were object detection, observation, and characterization, where multispectral electro-optical devices and radar were employed due to limited visual acuity and intermittent presentation of the phenomena. The primary means of detection utilized a 3 cm X-band radar operating in two scan geometries, the X- and Y-axis. Multispectral electro-optical devices were utilized as a secondary means of detection and identification. Data was emphasized using HF and LF detectors and spectrum analyzers incorporating EM, ultrasonic, magnetic, and RF field transducers to record spectral data in these domains. Data collection concentrated on characterizing VIS, NIR, SWIR, LWIR, UVA, UVB, UVC, and the higher energy spectral range of ionizing radiation (alpha, beta, gamma, and X-ray) recorded by Geiger-Müller counters as well as special purpose semiconductor diode sensors.
文摘目的探讨血清肌酐/半胱氨酸蛋白酶抑制剂C(sCr/CysC)比值对胰腺癌早期诊断和预后评估的价值。方法回顾性分析苏州大学附属第一医院2020年1月至2021年12月收治的60例初诊胰腺癌患者、30例胰腺良性肿瘤患者和30例健康对照者的临床资料。比较三组间sCr/CysC比值、C反应蛋白(CRP)、L3骨骼肌指数(L3-SMI)、Alb和CA199水平的差异。采用ROC曲线分析sCr/CysC比值对胰腺癌的诊断效能。根据sCr/CysC比值中位数将胰腺癌患者分为高比值组和低比值组,应用Kaplan-Meier生存曲线和Cox回归模型分析sCr/CysC比值对胰腺癌预后的预测价值。结果与胰腺良性肿瘤组和健康对照组相比,胰腺癌组的sCr/CysC比值和Alb水平显著降低,而CRP水平明显升高(均P<0.05)。与低sCr/CysC比值组相比,高比值组患者的性别构成、年龄和L3 SMI水平差异有统计学意义(均P<0.05)。sCr/CysC比值对胰腺癌的诊断ROC曲线下面积为0.640(95%CI:0.524~0.756,P<0.05),在cut-off值为0.69时敏感性为46.7%,特异性为83.3%。相关分析显示,sCr/CysC比值与L3-SMI呈正相关(r=0.425,P<0.01)。生存分析表明,高sCr/CysC比值组患者的中位生存期显著长于低比值组(379 d vs 210 d,P<0.01)。Cox回归分析确认sCr/CysC比值是胰腺癌预后的独立危险因素(HR=0.151,95%CI:0.028~0.826,P<0.05)。结论sCr/CysC比值可能是胰腺癌早期诊断和预后评估的有效指标,有望为胰腺癌的临床诊疗提供参考。
