The patterns of material accumulation in buildings and infrastructure accompanied by rapid urbanization offer an important,yet hitherto largely missing stock perspective for facilitating urban system engineering and i...The patterns of material accumulation in buildings and infrastructure accompanied by rapid urbanization offer an important,yet hitherto largely missing stock perspective for facilitating urban system engineering and informing urban resources,waste,and climate strategies.However,our existing knowledge on the patterns of built environment stocks across and particularly within cities is limited,largely owing to the lack of sufficient high spatial resolution data.This study leveraged multi-source big geodata,machine learning,and bottom-up stock accounting to characterize the built environment stocks of 50 cities in China at 500 m fine-grained levels.The per capita built environment stock of many cities(261 tonnes per capita on average)is close to that in western cities,despite considerable disparities across cities owing to their varying socioeconomic,geomorphology,and urban form characteristics.This is mainly owing to the construction boom and the building and infrastructure-driven economy of China in the past decades.China’s urban expansion tends to be more“vertical”(with high-rise buildings)than“horizontal”(with expanded road networks).It trades skylines for space,and reflects a concentration-dispersion-concentration pathway for spatialized built environment stocks development within cities in China.These results shed light on future urbanization in developing cities,inform spatial planning,and support circular and low-carbon transitions in cities.展开更多
Acoustic modal behavior is reported for an L-shape hydrophone array during the passage of a strong nonlinear internal wave packet. Acoustic track is nearly parallel to the front of nonlinear internal waves. Through mo...Acoustic modal behavior is reported for an L-shape hydrophone array during the passage of a strong nonlinear internal wave packet. Acoustic track is nearly parallel to the front of nonlinear internal waves. Through modal decomposition at the vertical array, acoustic modes are identified. Modal evolution along the horizontal array then is examined during a passing internal wave. Strong intensity fluctuations of individual modes are observed before and during the internal waves packet passes the fixed acoustic track showing a detailed evolution of the waveguide modal behavior. Acoustic refraction created either uneven distribution of modal energy over the horizontal array or additional returns observable at the entire L-shape array. Acoustic ray-mode simulations are used to phenomenologically explain the observed modal behavior.展开更多
Pilot-assisted channel estimation has been investigated to improve the performance of OFDM based LTE systems. LS and MMSE method do not perform excellently because they do not consider the inherent sparse feature of w...Pilot-assisted channel estimation has been investigated to improve the performance of OFDM based LTE systems. LS and MMSE method do not perform excellently because they do not consider the inherent sparse feature of wireless channel. The sparse feature of channel impulse response satisfies the requirement of using compressive sensing (CS) theory, which has recently gained much attention in signal processing. Result in the application of using compressive sensing to estimate fading channel. And it achieves a much better performance than that with traditional methods. In this paper, we propose heuristic channel estimation based on CS in LTE Downlink channel. According to the feature of recovery algorithm in CS, we design a modified pilot placement method. CS recovery algorithms for channel estimation don’t consider the statistics character of channel. So we proposed an optimization method which combines the CS and noise reduction. First we get initial channel statistics obtained by LS. Let the channel statistics as the heuristic information input of CS recovery algorithm. Then we perform CS recovery algorithm to estimate channel. Simulation results show this approach significantly reduces the complexity of channel estimation and get a better mean square error (MSE) performance.展开更多
目的探讨腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)、Yes相关蛋白1(yes-associated protein 1,YAP1)、E-cadherin蛋白在胃癌组织中的表达与临床各病理特征的关系。方法选取2019年1月至2020年1月在宁...目的探讨腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)、Yes相关蛋白1(yes-associated protein 1,YAP1)、E-cadherin蛋白在胃癌组织中的表达与临床各病理特征的关系。方法选取2019年1月至2020年1月在宁夏医科大学总医院行胃癌根治术患者的组织标本60例,采用免疫组化法检测AMPK、YAP1、E-cadherin在胃癌组织和相应癌旁正常组织中的表达,统计各基因在胃癌组织中的表达阳性率,分析其与临床各病理特征的关系;进一步分析胃癌组织中AMPK、YAP1、E-cadherin蛋白表达的相关性。结果60例胃癌组织中,AMPK、YAP1、E-cadherin的蛋白表达阳性率分别为40.00%、80.00%、36.67%,而癌旁正常组织中的表达阳性率分别为85.00%、28.33%、75.00%;AMPK、E-cadherin在胃癌组织中的表达阳性率均低于癌旁组织(P均<0.05),YAP1在胃癌组织中的表达阳性率高于癌旁组织(P<0.05)。AMPK的表达与脉管浸润、肿瘤分化程度、淋巴结转移及TNM分期相关(P均<0.05),而与性别、年龄、肿瘤大小无关(P均>0.05);YAP1的表达与肿瘤大小、脉管浸润、肿瘤分化程度、淋巴结转移及TNM分期相关(P均<0.05),而与性别、年龄无关(P均<0.05);E-cadherin的表达与脉管浸润、淋巴结转移及TNM分期相关(P均<0.05),与性别、年龄、肿瘤大小、肿瘤分化程度无关(P均>0.05)。AMPK与YAP1的表达呈负相关(P<0.01),与E-cadherin的表达呈正相关(P<0.01),YAP1与E-cadherin的表达呈负相关(P<0.01)。结论AMPK、YAP1、E-cadherin蛋白均在胃癌组织中异常表达,与胃癌的进展有一定相关性,联合检测可能对胃癌的诊治具有指导价值。展开更多
To better understand waterlogging effect on leaf senescence in winter rapseed (Brassica napus L.) during flowering stage, experiments were designed to explore foliar K application influences on adverse effects of wate...To better understand waterlogging effect on leaf senescence in winter rapseed (Brassica napus L.) during flowering stage, experiments were designed to explore foliar K application influences on adverse effects of waterlogging stress. Winter rapeseed was sprayed with K after waterlogging at initial flowering stage. Results indicated that waterlogging significantly decreased leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr). It also declined maximum quantum yield of PS II (Fv/Fm), quantum yield of electron transport (ΦPS II) and photochemical quenching (qP), but increased leaf non-photochemical quenching (NPQ) and minimal fluorescence (Fo). Interestingly, exogenous application of K significantly alleviated waterlogging-induced photosynthesis inhibition. Foliar K application increased RuBisCO activation, chlorophyll and soluble protein contents, while significantly decreased MDA content under waterlogging stress. Moreover, K supplementation improved accumulation of K+, Ca2+, Mg2+, N, Zn2+, Mn2+, Fe2+ in leaves. In general, foliar K application is effective inalleviating deleterious effects of waterlogging stress and delays leaf senescence of winter rapeseed.展开更多
BACKGROUND Abnormalities in the melanocortin receptor 4(MC4R)gene often lead to obesity,but are rarely associated with other conditions such as epilepsy and sleep disorder.CASE SUMMARY Here,we present a case of a male...BACKGROUND Abnormalities in the melanocortin receptor 4(MC4R)gene often lead to obesity,but are rarely associated with other conditions such as epilepsy and sleep disorder.CASE SUMMARY Here,we present a case of a male obese child with a heterozygous variant in MC4R(c.494G>A,p.Arg165Gln)inherited from his father,who presented with disordered sleep and abnormal facial movements.Examination through melatonin rhythm testing and electroencephalography led to a diagnosis of sleep disorder and epilepsy,as his melatonin rhythm was markedly distorted and the electroencephalography revealed epileptic discharges.He received treatment with an antiepileptic drug;however,the therapy was ineffective and the sleep disorder appeared to be deteriorating.Subsequently,we initiated adjuvant treatment with melatonin.Upon re-examination,his body mass index had decreased,the sleep disturbance had resolved,and his seizures were well controlled.Electroencephalography review was normal,and a typical melatonin rhythm was restored.CONCLUSION We concluded that,in addition to causing obesity,abnormalities in the MC4R gene may contribute to the development of sleep disorders and epilepsy,and that melatonin can be used as an adjuvant therapy to alleviate these symptoms.展开更多
基金supported by the National Natural Science Foundation of China (71991484,42271471,72088101,and 41830645)Danish Agency for Higher Education and Science (International Network Project,0192-00056B)the Fundamental Research Funds for the Central Universities (Peking University).
文摘The patterns of material accumulation in buildings and infrastructure accompanied by rapid urbanization offer an important,yet hitherto largely missing stock perspective for facilitating urban system engineering and informing urban resources,waste,and climate strategies.However,our existing knowledge on the patterns of built environment stocks across and particularly within cities is limited,largely owing to the lack of sufficient high spatial resolution data.This study leveraged multi-source big geodata,machine learning,and bottom-up stock accounting to characterize the built environment stocks of 50 cities in China at 500 m fine-grained levels.The per capita built environment stock of many cities(261 tonnes per capita on average)is close to that in western cities,despite considerable disparities across cities owing to their varying socioeconomic,geomorphology,and urban form characteristics.This is mainly owing to the construction boom and the building and infrastructure-driven economy of China in the past decades.China’s urban expansion tends to be more“vertical”(with high-rise buildings)than“horizontal”(with expanded road networks).It trades skylines for space,and reflects a concentration-dispersion-concentration pathway for spatialized built environment stocks development within cities in China.These results shed light on future urbanization in developing cities,inform spatial planning,and support circular and low-carbon transitions in cities.
基金Supported by U.S. Office of Naval Research,Ocean Acoustics Program(322OA)under Nos.N00014-11-1-0701 and N00014-13-1-0306
文摘Acoustic modal behavior is reported for an L-shape hydrophone array during the passage of a strong nonlinear internal wave packet. Acoustic track is nearly parallel to the front of nonlinear internal waves. Through modal decomposition at the vertical array, acoustic modes are identified. Modal evolution along the horizontal array then is examined during a passing internal wave. Strong intensity fluctuations of individual modes are observed before and during the internal waves packet passes the fixed acoustic track showing a detailed evolution of the waveguide modal behavior. Acoustic refraction created either uneven distribution of modal energy over the horizontal array or additional returns observable at the entire L-shape array. Acoustic ray-mode simulations are used to phenomenologically explain the observed modal behavior.
文摘Pilot-assisted channel estimation has been investigated to improve the performance of OFDM based LTE systems. LS and MMSE method do not perform excellently because they do not consider the inherent sparse feature of wireless channel. The sparse feature of channel impulse response satisfies the requirement of using compressive sensing (CS) theory, which has recently gained much attention in signal processing. Result in the application of using compressive sensing to estimate fading channel. And it achieves a much better performance than that with traditional methods. In this paper, we propose heuristic channel estimation based on CS in LTE Downlink channel. According to the feature of recovery algorithm in CS, we design a modified pilot placement method. CS recovery algorithms for channel estimation don’t consider the statistics character of channel. So we proposed an optimization method which combines the CS and noise reduction. First we get initial channel statistics obtained by LS. Let the channel statistics as the heuristic information input of CS recovery algorithm. Then we perform CS recovery algorithm to estimate channel. Simulation results show this approach significantly reduces the complexity of channel estimation and get a better mean square error (MSE) performance.
文摘目的探讨腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)、Yes相关蛋白1(yes-associated protein 1,YAP1)、E-cadherin蛋白在胃癌组织中的表达与临床各病理特征的关系。方法选取2019年1月至2020年1月在宁夏医科大学总医院行胃癌根治术患者的组织标本60例,采用免疫组化法检测AMPK、YAP1、E-cadherin在胃癌组织和相应癌旁正常组织中的表达,统计各基因在胃癌组织中的表达阳性率,分析其与临床各病理特征的关系;进一步分析胃癌组织中AMPK、YAP1、E-cadherin蛋白表达的相关性。结果60例胃癌组织中,AMPK、YAP1、E-cadherin的蛋白表达阳性率分别为40.00%、80.00%、36.67%,而癌旁正常组织中的表达阳性率分别为85.00%、28.33%、75.00%;AMPK、E-cadherin在胃癌组织中的表达阳性率均低于癌旁组织(P均<0.05),YAP1在胃癌组织中的表达阳性率高于癌旁组织(P<0.05)。AMPK的表达与脉管浸润、肿瘤分化程度、淋巴结转移及TNM分期相关(P均<0.05),而与性别、年龄、肿瘤大小无关(P均>0.05);YAP1的表达与肿瘤大小、脉管浸润、肿瘤分化程度、淋巴结转移及TNM分期相关(P均<0.05),而与性别、年龄无关(P均<0.05);E-cadherin的表达与脉管浸润、淋巴结转移及TNM分期相关(P均<0.05),与性别、年龄、肿瘤大小、肿瘤分化程度无关(P均>0.05)。AMPK与YAP1的表达呈负相关(P<0.01),与E-cadherin的表达呈正相关(P<0.01),YAP1与E-cadherin的表达呈负相关(P<0.01)。结论AMPK、YAP1、E-cadherin蛋白均在胃癌组织中异常表达,与胃癌的进展有一定相关性,联合检测可能对胃癌的诊治具有指导价值。
文摘To better understand waterlogging effect on leaf senescence in winter rapseed (Brassica napus L.) during flowering stage, experiments were designed to explore foliar K application influences on adverse effects of waterlogging stress. Winter rapeseed was sprayed with K after waterlogging at initial flowering stage. Results indicated that waterlogging significantly decreased leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr). It also declined maximum quantum yield of PS II (Fv/Fm), quantum yield of electron transport (ΦPS II) and photochemical quenching (qP), but increased leaf non-photochemical quenching (NPQ) and minimal fluorescence (Fo). Interestingly, exogenous application of K significantly alleviated waterlogging-induced photosynthesis inhibition. Foliar K application increased RuBisCO activation, chlorophyll and soluble protein contents, while significantly decreased MDA content under waterlogging stress. Moreover, K supplementation improved accumulation of K+, Ca2+, Mg2+, N, Zn2+, Mn2+, Fe2+ in leaves. In general, foliar K application is effective inalleviating deleterious effects of waterlogging stress and delays leaf senescence of winter rapeseed.
基金National Natural Science Foundation of China,No.81671279Big Data and Artificial Intelligence Research and Development Project of the Chinese PLA General Hospital,No.2019MBD-004.
文摘BACKGROUND Abnormalities in the melanocortin receptor 4(MC4R)gene often lead to obesity,but are rarely associated with other conditions such as epilepsy and sleep disorder.CASE SUMMARY Here,we present a case of a male obese child with a heterozygous variant in MC4R(c.494G>A,p.Arg165Gln)inherited from his father,who presented with disordered sleep and abnormal facial movements.Examination through melatonin rhythm testing and electroencephalography led to a diagnosis of sleep disorder and epilepsy,as his melatonin rhythm was markedly distorted and the electroencephalography revealed epileptic discharges.He received treatment with an antiepileptic drug;however,the therapy was ineffective and the sleep disorder appeared to be deteriorating.Subsequently,we initiated adjuvant treatment with melatonin.Upon re-examination,his body mass index had decreased,the sleep disturbance had resolved,and his seizures were well controlled.Electroencephalography review was normal,and a typical melatonin rhythm was restored.CONCLUSION We concluded that,in addition to causing obesity,abnormalities in the MC4R gene may contribute to the development of sleep disorders and epilepsy,and that melatonin can be used as an adjuvant therapy to alleviate these symptoms.
