BACKGROUND Quantitative fluorescent polymerase chain reaction(QF-PCR)is a rapid prenatal diagnostic method for abnormalities on chromosomes 21,18,and 13 and sex chromosomal aneuploidy.However,the value of QF-PCR in di...BACKGROUND Quantitative fluorescent polymerase chain reaction(QF-PCR)is a rapid prenatal diagnostic method for abnormalities on chromosomes 21,18,and 13 and sex chromosomal aneuploidy.However,the value of QF-PCR in diagnosing chromosomal structural abnormalities is limited.In this article,we report a confusing QF-PCR finding in a pregnant woman who underwent amniocentesis.CASE SUMMARY The short tandem repeat marker AMXY(Xp22.2/Yp11.2)located on the sex chromosome exhibited a trisomic biallelic pattern,indicating that the karyotype of the fetus might be 47,XYY.Chromosome analysis performed on cultured amniocytes showed a normal male karyotype of the fetus.Copy number variation sequencing confirmed a 500 kb duplication at Yp11.2-Yp11.2(chrY:6610001_7110000)and a 250 kb duplication at Yp11.2-Yp11.2(chrY:7110001_7360000).CONCLUSION In conclusion,the comprehensive application of different methods could achieve a higher detection rate and accuracy for the prenatal diagnosis of chromosomal disorders through chromosomal testing.展开更多
Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing met...Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing methods assume that sufficient samples of each failure mode are available,which may be unrealistic,especially for those modes of low occurrence frequency but with high risk.To address this issue,this work proposes a novel fault diagnosis method that only requires the power signals generated under normal RPS operations in the training stage.Specifically,the failure modes of RPS are distinguished through constructing a reasoning diagram,whose nodes are either binary logic problems or those that can be decomposed into the problems of the binary logic.Then,an unsupervised method for the signal segmentation and a fault detection method are combined to make decisions for each binary logic problem.Based on the results of decisions,the diagnostic rules are established to identify the failure modes.Finally,the data collected from multiple real-world RPSs are used for validation and the results demonstrate that the proposed method outperforms the benchmark in identifying the faults of RPSs.展开更多
Xuefu Zhuyu decoction has been used for treating traumatic brain injury and improving post-traumatic dysfunction, but its mechanism of action needs further investigation. This study established rat models of traumatic...Xuefu Zhuyu decoction has been used for treating traumatic brain injury and improving post-traumatic dysfunction, but its mechanism of action needs further investigation. This study established rat models of traumatic brain injury by controlled cortical impact. Rat models were intragastrically administered 9 and 18 g/kg Xuefu Zhuyu decoction once a day for 14 or 21 days. Changes in neurological function were assessed by modified neurological severity scores and the Morris water maze. Immunohistochemistry, western blot assay, and reverse-transcription polymerase chain reaction were used to analyze synapsin protein and m RNA expression at the injury site of rats. Our results showed that Xuefu Zhuyu decoction visibly improved neurological function of rats with traumatic brain injury. These changes were accompanied by increased expression of synaptophysin, synapsin Ⅰ, and postsynaptic density protein-95 protein and m RNA in a dose-dependent manner. These findings indicate that Xuefu Zhuyu decoction increases synapsin expression and improves neurological deficits after traumatic brain injury.展开更多
Primary esophageal or gastric melanoma is a very rare disease with early metastasis. Due to its atypical symptom and less efficiency of chemotherapy and radiotherapy, the prognosis of esophageal or gastric melanoma is...Primary esophageal or gastric melanoma is a very rare disease with early metastasis. Due to its atypical symptom and less efficiency of chemotherapy and radiotherapy, the prognosis of esophageal or gastric melanoma is still very poor. Surgical resection remains the preferential treatment for esophageal or gastric melanoma. Here we present an extremely rare case of primary advanced esophago-gastric melanoma. Debulking surgery was performed without chemotherapy or radiotherapy. However, abdominal recurrence and hepatic metastases were found within one month by a postoperative follow-up computed tomography. Three and a half months after surgical resection, the patient died of extensive abdominal metastasis.展开更多
Sustainable conversion of waste plastics into valuable carbon materials for diverse applications provides a promising strategy to dispose the municipal and industrial waste plastics.However,it remains a challenge to p...Sustainable conversion of waste plastics into valuable carbon materials for diverse applications provides a promising strategy to dispose the municipal and industrial waste plastics.However,it remains a challenge to precisely control the crosslinking reaction for transforming waste polyesters into N-doped porous carbon (NPC) with well-defined microstructures.Herein,we put forwards a strategy of stepwise crosslinking using melamine and ZnCl_(2)/NaCl eutectic salts to convert poly (ethylene terephthalate)(PET) into NPC at 550℃.We prove that firstly melamine reacts with PET degradation products to form a crosslinking structure,and subsequently ZnCl_(2)/NaCl promote the dehydration and decarboxylation of the crosslinking structure to generate a more thermally stable crosslinking structure.The coordination of two tandem crosslinking reactions is critical to control the microstructure of NPC.Without activations,NPC shows large specific surface area of 1173 m~2g^(-1),abundant N dopants,and rich oxygen-containing groups.These combined features endure NPC with excellent performance in CO_(2) capture and solar steam generation,e.g.,high CO_(2) adsorption capacity of 6.47 mmol g^(-1) and evaporation rate of 1.62 kg m^(-2)h^(-1).More importantly,NPC is compared to or prevails over previous carbon-based CO_(2) adsorbents or photothermal materials.This work will advance the research on “green” reutilization of low-cost polyester wastes to prepare sustainable carbon for solar energy conversion,environmental protection,etc.展开更多
The use of agricultural straw for algal bloom control has been studied for more than 30 years.In this article,we have reviewed the promising potentials of using agricultural straw as source of anti-algal agents,includ...The use of agricultural straw for algal bloom control has been studied for more than 30 years.In this article,we have reviewed the promising potentials of using agricultural straw as source of anti-algal agents,including the effectiveness of each major straw type so far used in this regard,and the investigated algal species.Various pre-treatment methods have also been widely reviewed.Significant progress has been made in natural product chemistry and molecular biology with regards to agricultural straw,especially in relation to the extraction of antialgal allelochemicals,degradation processes of agricultural straws and the mechanisms through which these inhibitions occur.The development of biotechnologies using agricultural straw to successfully inhibit growth of bloom forming algae has been generally accepted as environmentally friendly.The current research status and that of the future should include isolation and discovery of antialgal allelochemicals,development of models that would illustrate the sequence of physiologic events that match the species-specific inhibitor phenomenon,and products fit in the field applications.展开更多
Structural vibrations in Tip-Tilt modes usually affect the closed-loop performance of astronomically optical telescopes.In this paper,the state of art control methods—proportional integral(PI)control,linear quadratic...Structural vibrations in Tip-Tilt modes usually affect the closed-loop performance of astronomically optical telescopes.In this paper,the state of art control methods—proportional integral(PI)control,linear quadratic Gaussian(LQG)control,disturbance feed forward(DFF)control,and disturbance observer control(DOBC)of Tip-Tilt mirror to reject vibrations are first reviewed,and then compared systematically and comprehensively.Some mathematical transformations allow PI,LQG,DFF,and DOBC to be described in a uniform framework of sensitivity function that expresses their advantages and disadvantages.In essence,feed forward control based-inverse model is the main idea of current techniques,which is dependent on accuracies of models in terms of Tip-Tilt mirror and vibrations.DOBC can relax dependences on accuracy model,and therefore this survey concentrates on concise tutorials of this method with clear descriptions of their features in the control area of disturbance rejections.Its applications in various conditions are reviewed with emphasis on the effectiveness.Finally,the open problems,challenges and research prospects of DOBC of Tip-Tilt mirror are discussed.展开更多
In this paper, a cascade acceleration feedback control(AFC) enhanced by a disturbance observation and compensation(DOC) method is proposed to improve the tracking precision of telescope systems.Telescope systems usual...In this paper, a cascade acceleration feedback control(AFC) enhanced by a disturbance observation and compensation(DOC) method is proposed to improve the tracking precision of telescope systems.Telescope systems usually suffer some uncertain disturbances, such as wind load, nonlinear friction and other unknown disturbances. To ensure tracking precision, an acceleration feedback loop which can increase the stiffness of such a system is introduced. Moreover, to further improve the tracking precision, we introduce the DOC method which can accurately estimate the disturbance and compensate it. Furthermore,the analysis of tracking accuracy used by this method is proposed. Finally, a few comparative experimental results show that the proposed control method has excellent performance for reducing the tracking error of a telescope system.展开更多
Objective:Traditional Chinese medicine(TCM)and modern medicine have both been used in arresting malignant transformation of chronic atrophic gastritis(CAG)in China with good therapeutic effect.However,no studies have ...Objective:Traditional Chinese medicine(TCM)and modern medicine have both been used in arresting malignant transformation of chronic atrophic gastritis(CAG)in China with good therapeutic effect.However,no studies have been undertaken to assess the risk of malignant transformation in CAG patients using both modern medicine and TCM features.Our study aimed to develop risk assessment models for malignant transformation of CAG combining indicators of both TCM and modern medicine.These models will facilitate early warning and control of malignant transformation of CAG from the perspective of evidence-based integrative medicine.Methods:In the proposed registry study,a total of 1000 eligible CAG patients will be recruited from four hospitals in China.A 10-year follow-up study will be conducted both on-site and off-site to track the events of malignant transformation.Frequency analysis and chi-squared tests will be used to perform the comparative analysis on the prevalence of malignant transformation events and indicators in TCM or modern medicine in different groups.A multivariate Cox proportional hazard model will be used to perform correlation analyses of malignant transformation events and factors of TCM or modern medicine.Conclusion:The proposed study has been designed with a large sample size and long follow-up period,in which wide-ranging modern medicine and TCM indicators can be gathered over the whole process of malignant transformation of CAG.Based on this study,risk assessment models for malignant transformation ofCAGmaybe constructed fromthe perspective of integrative medicine.This may provide clinicians and patients with an optimized early warning system as well as prevention strategies for malignant transformation of CAG.展开更多
Wood-based bilayer solar evaporators,which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation,low heat conduction,renewability,and high light absorba...Wood-based bilayer solar evaporators,which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation,low heat conduction,renewability,and high light absorbability,hold great promise for water purification.However,previous studies suffer from low evaporation rates and high cost of coatings,and lack a deep understanding how the porous structures of coating layer function.Herein,a novel bilayer solar evaporator is designed through facile surface coating of wood by low-cost porous carbon from controlled carbonization of polyester waste.The porous carbon bears rich oxygen-containing groups,well-controlled micro-/meso-/macropores,and high surface areas(1164 m^(2) g^(−1)).It is proved that porous carbon improves sunlight absorption and promotes the formation of numerous water clusters to reduce water evaporation enthalpy.Owing to these combined features,the bilayer solar evaporator exhibits high evaporation rate(2.38 kg m^(−2) h^(−1)),excellent longterm stability,and good salt resistance.More importantly,a large-scale solar desalination device for outdoor experiments is developed to produce freshwater from seawater.The daily freshwater production amount(3.65 kg m^(−2))per unit area meets the daily water consumption requirement of one adult.These findings will inspire new paradigms toward developing efficient solar steaming technologies for desalination to address global freshwater shortage.展开更多
Glaciers are crucial water resources for arid inland rivers in Northwest China.In recent decades,glaciers are largely experiencing shrinkage under the climate-warming scenario,thereby exerting tremendous influences on...Glaciers are crucial water resources for arid inland rivers in Northwest China.In recent decades,glaciers are largely experiencing shrinkage under the climate-warming scenario,thereby exerting tremendous influences on regional water resources.The primary role of understudying watershed scale glacier changes under changing climatic conditions is to ensure sustainable utilization of regional water resources,to prevent and mitigate glacier-related disasters.This study maps the current(2020)distribution of glacier boundaries across the Kaidu-Kongque river basin,south slope of Tianshan Mountains,and monitors the spatial evolution of glaciers over five time periods from 2000-2020 through thresholded band ratios approach,using 25 Landsat images at 30 m resolution.In addition,this study attempts to understand the role of climate characteristics for variable response of glacier area.The results show that the total area of glaciers was 398.21 km^(2)in 2020.The glaciers retreated by about 1.17 km^(2)/a(0.26%/a)from 2000 to 2020.The glaciers were reducing at a significantly rapid rate between 2000 and 2005,a slow rate from 2005 to 2015,and an accelerated rate during 2015-2020.The meteorological data shows slight increasing trends of mean annual temperature(0.02℃/a)and annual precipitation(2.07 mm/a).The correlation analysis demonstrates that the role of temperature presents more significant correlation with glacier recession than precipitation.There is a temporal hysteresis in the response of glacier change to climate change.Increasing trend of temperature in summer proves to be the driving force behind the Kaidu-Kongque basin glacier recession during the recent 20 years.展开更多
Signals from lumbar primary afferent fibers are important for modulating locomotion of the hind-limbs.However,silver impregnation techniques,autoradiography,wheat germ agglutinin-horseradish peroxidase and cholera tox...Signals from lumbar primary afferent fibers are important for modulating locomotion of the hind-limbs.However,silver impregnation techniques,autoradiography,wheat germ agglutinin-horseradish peroxidase and cholera toxin B subunit-horseradish peroxidase cannot image the central projections and connections of the dorsal root in detail.Thus,we injected 3-k Da Texas red-dextran amine into the proximal trunks of L4 dorsal roots in adult rats.Confocal microscopy results revealed that numerous labeled arborizations and varicosities extended to the dorsal horn from T12–S4,to Clarke's column from T10–L2,and to the ventral horn from L1–5.The labeled varicosities at the L4 cord level were very dense,particularly in laminae I–Ⅲ,and the density decreased gradually in more rostral and caudal segments.In addition,they were predominately distributed in laminae I–IV,moderately in laminae V–VⅡ and sparsely in laminae VⅢ–X.Furthermore,direct contacts of lumbar afferent fibers with propriospinal neurons were widespread in gray matter.In conclusion,the projection and connection patterns of L4 afferents were illustrated in detail by Texas red-dextran amine-dorsal root tracing.展开更多
A new material is prepared by impregnating the expanded graphite(EG) into ethanol solutions of metal acetate and then drying and reducing it in H2.It contains the EG and the nanoparticles of the magnetic Ni–Fe alloy ...A new material is prepared by impregnating the expanded graphite(EG) into ethanol solutions of metal acetate and then drying and reducing it in H2.It contains the EG and the nanoparticles of the magnetic Ni–Fe alloy for the electromagnetic shielding.Its morphology,phase structure,magnetic properties,and electromagnetic shielding effectiveness(SE) are investigated in our experiment.It shows that the morphology,the phase structure,and the magnetic property of the composite can be modified by altering the Ni content in the alloy nanoparticles.Interestingly,the SE can be enhanced to 54–70 d B at low frequencies(300 kHz–10 MHz) by dispersing the magnetic nanoparticles onto EG.展开更多
This paper proposes a dual-motor configuration to enhance closed-loop performance of a telescope control system. Two identical motors are mounted on each side of a U-type frame to drive the telescope elevation axis in...This paper proposes a dual-motor configuration to enhance closed-loop performance of a telescope control system. Two identical motors are mounted on each side of a U-type frame to drive the telescope elevation axis instead of a single motor drive, which is usually used in a classical design. This new configuration and mechanism can reduce the motor to half the size used in the former design, and it also provides some other advantages. A master-slave current control mode is employed to synchronize the two motors. Acceleration feedback control is utilized to further enhance the servo performance. Extensive experiments are used to validate the effectiveness of the proposed control algorithm in synchronization, disturbance attenuation and low-velocity tracking.展开更多
Porous carbon materials have exhibited a series of promising applications in supercapacitors and other research fields,yet still confronting the complicated synthetic procedures and massive usage of toxic reagents.Her...Porous carbon materials have exhibited a series of promising applications in supercapacitors and other research fields,yet still confronting the complicated synthetic procedures and massive usage of toxic reagents.Herein,we propose a green and one-pot method to produce heteroatomdoped hierarchical porous carbon materials in large-scale without any toxic reagents employed.Eventually,the as-prepared nitrogen-doped porous carbon(NPC)displays a high specific surface area of 2018 m^(2)g^(-1)together with abundant heteroatom dopants(14.8 wt%O and 1.03 wt%N).The potassium carbonate template can be recycled via a simple rinsing and re-precipitation process.Furthermore,the as-prepared nitrogen-doped porous carbon delivers a high specific capacitance of 361 F g^(-1)at 0.5 A g^(-1)and excellent rate capability of 240 F g^(-1)at 20 A g^(-1)(66.5%capacitance retention).Finally,considering the low-price raw materials and facile green synthesis procedure,the present approach can be easily scalable to prepare biomass-derived heteroatoms doped porous carbon,which is not only applicable for supercapacitor but also for other research fields.展开更多
Solar evaporation is recognized as a prospective technique to produce freshwater from non-drinkable water using inexhaustible solar energy.However,it remains a challenge to fabricate low-cost solar evaporators with ob...Solar evaporation is recognized as a prospective technique to produce freshwater from non-drinkable water using inexhaustible solar energy.However,it remains a challenge to fabricate low-cost solar evaporators with obviously reduced water evaporation enthalpy to achieve high evaporation rates.Herein,N,O dual-doped carbon foam(NCF)is fabricated from the lowtemperature carbonization of poly(ethylene terephthalate)(PET)waste by melamine/molten salts at 340℃.During carbonization,melamine reacts with carboxylic acids of PET degradation products to yield a crosslinking network,and then molten salts catalyze the decarboxylation and dehydration to construct a stable framework.Owing to rich N,O-containing groups,3D interconnected pores,super-hydrophilicity,and ultra-low thermal conductivity(0.0599 W m^(−1) K^(−1)),NCF not only achieves high light absorbance(ca.99%)and solar-to-thermal conversion,but also promotes the formation of water cluster to reduce water evaporation enthalpy by ca.37%.Consequently,NCF exhibits a high evaporation rate(2.4 kg m^(−2) h^(−1)),surpassing the-state-of-the-art solar evaporators,and presents good antiacid/basic abilities,long-term salt-resistance,and self-cleaning ability.Importantly,a large-scale NCF-based outdoor solar desalination device is developed to produce freshwater.The daily freshwater production amount per unit area(6.3 kg)meets the two adults’daily water consumption.The trash-to-treasure strategy will give impetus to the development of low-cost,advanced solar evaporators from waste plastics for addressing the global freshwater shortage.展开更多
The represent paper will study the performance of the power plant with the combination of dry and wet cooling systems in different operating conditions. A thermodynamic performance analysis of the steam cycle system w...The represent paper will study the performance of the power plant with the combination of dry and wet cooling systems in different operating conditions. A thermodynamic performance analysis of the steam cycle system was performed by means of a program code dedicated to power plant modeling in design operating condition. Then the off-design behavior was studied by varying not only the ambient temperature and relative humidity but also several parameters connected to the cooling performance, like the exhaust steam flow rate, the air cooling fan load and the number of operating cooling water pumps and cooling towers. The result is an optimum set of variables allowing the dry and wet cooling system be regulated in such a way that the maximum power is achieved and low water consumption.展开更多
Earth’s aurora is a luminescent phenomenon generated by the interaction between magnetospheric precipitating particles and the upper atmosphere;it plays an important role in magnetosphere–ionosphere(M-I)coupling.The...Earth’s aurora is a luminescent phenomenon generated by the interaction between magnetospheric precipitating particles and the upper atmosphere;it plays an important role in magnetosphere–ionosphere(M-I)coupling.The transpolar arc(TPA)is a discrete auroral arc distributed in the noon-midnight direction poleward of the auroral oval and connects the dayside to the nightside sectors of the auroral oval.Studying the seasonal variation of TPA events can help us better understand the long-term variation of the interaction between the solar wind,the magnetosphere,and M-I coupling.However,a statistical study of the seasonal variation of TPA incidence has not previously been carried out.In this paper,we have identified 532 TPA events from the IMAGE database(2000–2005)and the Polar database(1996–2002),and calculated the incidence of TPA events for different months.We find a semiannual variation in TPA incidence.Clear peaks in the incidence of TPAs occur in March and September;a less pronounced peak appears in November.We also examine seasonal variation in the northward interplanetary magnetic field(IMF)over the same time period.The intensity and occurrence rate of the northward IMF exhibit patterns similar to that of the TPA incidence.Having studied IMF Bz before TPA onset,we find that strong and steady northward IMF conditions are favorable for TPA formation.We suggest that the semiannual variation observed in TPA incidence may be related to the Russell–McPherron(R-M)effect due to the projection effect of the IMF By under northward IMF conditions.展开更多
A simple theoretical modeling is made to describe the reflection features of the high power microwave (HPM) in the mixture-atmosphere. The time-space dependent mixture-atmosphere is generated by ionization of the neut...A simple theoretical modeling is made to describe the reflection features of the high power microwave (HPM) in the mixture-atmosphere. The time-space dependent mixture-atmosphere is generated by ionization of the neutral molecules in atmosphere. Reflection will occur when HPM propagates in such mixture-atmosphere. The reflection characteristic of the HPM propagation in the mixture-atmosphere is investigated by FDTD numerical experiments in inhomogeneous medium, the influence on the reflection for different HPM parameters is concluded. An additional stability conditions for the FDTD difference scheme of the HPM mixture-atmosphere propagation model are presented.展开更多
文摘BACKGROUND Quantitative fluorescent polymerase chain reaction(QF-PCR)is a rapid prenatal diagnostic method for abnormalities on chromosomes 21,18,and 13 and sex chromosomal aneuploidy.However,the value of QF-PCR in diagnosing chromosomal structural abnormalities is limited.In this article,we report a confusing QF-PCR finding in a pregnant woman who underwent amniocentesis.CASE SUMMARY The short tandem repeat marker AMXY(Xp22.2/Yp11.2)located on the sex chromosome exhibited a trisomic biallelic pattern,indicating that the karyotype of the fetus might be 47,XYY.Chromosome analysis performed on cultured amniocytes showed a normal male karyotype of the fetus.Copy number variation sequencing confirmed a 500 kb duplication at Yp11.2-Yp11.2(chrY:6610001_7110000)and a 250 kb duplication at Yp11.2-Yp11.2(chrY:7110001_7360000).CONCLUSION In conclusion,the comprehensive application of different methods could achieve a higher detection rate and accuracy for the prenatal diagnosis of chromosomal disorders through chromosomal testing.
基金supported by National Key R&D Program of China(2022YFB2602203)Talent Fund of Beijing Jiaotong University(2021RC274,I22L00131)National Natural Science Foundation of China(U1934219,52202392,52022010,U22A2046,52172322,62271486,62120106011,52172323)。
文摘Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing methods assume that sufficient samples of each failure mode are available,which may be unrealistic,especially for those modes of low occurrence frequency but with high risk.To address this issue,this work proposes a novel fault diagnosis method that only requires the power signals generated under normal RPS operations in the training stage.Specifically,the failure modes of RPS are distinguished through constructing a reasoning diagram,whose nodes are either binary logic problems or those that can be decomposed into the problems of the binary logic.Then,an unsupervised method for the signal segmentation and a fault detection method are combined to make decisions for each binary logic problem.Based on the results of decisions,the diagnostic rules are established to identify the failure modes.Finally,the data collected from multiple real-world RPSs are used for validation and the results demonstrate that the proposed method outperforms the benchmark in identifying the faults of RPSs.
基金supported by the National Natural Science Foundation of China,No.81673719,81173175 and 81303074a grant from China Postdoctoral Science Foundation,No.2016M600639 and 2017T100614
文摘Xuefu Zhuyu decoction has been used for treating traumatic brain injury and improving post-traumatic dysfunction, but its mechanism of action needs further investigation. This study established rat models of traumatic brain injury by controlled cortical impact. Rat models were intragastrically administered 9 and 18 g/kg Xuefu Zhuyu decoction once a day for 14 or 21 days. Changes in neurological function were assessed by modified neurological severity scores and the Morris water maze. Immunohistochemistry, western blot assay, and reverse-transcription polymerase chain reaction were used to analyze synapsin protein and m RNA expression at the injury site of rats. Our results showed that Xuefu Zhuyu decoction visibly improved neurological function of rats with traumatic brain injury. These changes were accompanied by increased expression of synaptophysin, synapsin Ⅰ, and postsynaptic density protein-95 protein and m RNA in a dose-dependent manner. These findings indicate that Xuefu Zhuyu decoction increases synapsin expression and improves neurological deficits after traumatic brain injury.
文摘Primary esophageal or gastric melanoma is a very rare disease with early metastasis. Due to its atypical symptom and less efficiency of chemotherapy and radiotherapy, the prognosis of esophageal or gastric melanoma is still very poor. Surgical resection remains the preferential treatment for esophageal or gastric melanoma. Here we present an extremely rare case of primary advanced esophago-gastric melanoma. Debulking surgery was performed without chemotherapy or radiotherapy. However, abdominal recurrence and hepatic metastases were found within one month by a postoperative follow-up computed tomography. Three and a half months after surgical resection, the patient died of extensive abdominal metastasis.
基金financially supported by the National Natural Science Foundation of China (No. 51903099)Huazhong University of Science and Technology (No. 3004013134)+1 种基金the 100 Talents Program of the Hubei Provincial Governmentthe Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences。
文摘Sustainable conversion of waste plastics into valuable carbon materials for diverse applications provides a promising strategy to dispose the municipal and industrial waste plastics.However,it remains a challenge to precisely control the crosslinking reaction for transforming waste polyesters into N-doped porous carbon (NPC) with well-defined microstructures.Herein,we put forwards a strategy of stepwise crosslinking using melamine and ZnCl_(2)/NaCl eutectic salts to convert poly (ethylene terephthalate)(PET) into NPC at 550℃.We prove that firstly melamine reacts with PET degradation products to form a crosslinking structure,and subsequently ZnCl_(2)/NaCl promote the dehydration and decarboxylation of the crosslinking structure to generate a more thermally stable crosslinking structure.The coordination of two tandem crosslinking reactions is critical to control the microstructure of NPC.Without activations,NPC shows large specific surface area of 1173 m~2g^(-1),abundant N dopants,and rich oxygen-containing groups.These combined features endure NPC with excellent performance in CO_(2) capture and solar steam generation,e.g.,high CO_(2) adsorption capacity of 6.47 mmol g^(-1) and evaporation rate of 1.62 kg m^(-2)h^(-1).More importantly,NPC is compared to or prevails over previous carbon-based CO_(2) adsorbents or photothermal materials.This work will advance the research on “green” reutilization of low-cost polyester wastes to prepare sustainable carbon for solar energy conversion,environmental protection,etc.
基金financially supported by the Major Science and Technology Program forWater Pollution Control and Treatment(2018ZX07208-009)the National Natural Science Foundation of China(21677122 and 21876148)+4 种基金the open fund of the Key Laboratory of Marine Eco-monitoring and Remediation Technology,Ministry of Natural Resources(MATHAB201809)the open fund of the Key Laboratory of Marine Ecosystem Dynamics,Second Institute of Oceanography,Ministry of Natural Resources(LMEB201709)Key Projects of Philosophy and Social Sciences Research,Ministry of Education(18JZD059)Fundamental Research Funds for the Central Universities(2019QNA4051)the China Scholarship Council(201806325035).
文摘The use of agricultural straw for algal bloom control has been studied for more than 30 years.In this article,we have reviewed the promising potentials of using agricultural straw as source of anti-algal agents,including the effectiveness of each major straw type so far used in this regard,and the investigated algal species.Various pre-treatment methods have also been widely reviewed.Significant progress has been made in natural product chemistry and molecular biology with regards to agricultural straw,especially in relation to the extraction of antialgal allelochemicals,degradation processes of agricultural straws and the mechanisms through which these inhibitions occur.The development of biotechnologies using agricultural straw to successfully inhibit growth of bloom forming algae has been generally accepted as environmentally friendly.The current research status and that of the future should include isolation and discovery of antialgal allelochemicals,development of models that would illustrate the sequence of physiologic events that match the species-specific inhibitor phenomenon,and products fit in the field applications.
文摘Structural vibrations in Tip-Tilt modes usually affect the closed-loop performance of astronomically optical telescopes.In this paper,the state of art control methods—proportional integral(PI)control,linear quadratic Gaussian(LQG)control,disturbance feed forward(DFF)control,and disturbance observer control(DOBC)of Tip-Tilt mirror to reject vibrations are first reviewed,and then compared systematically and comprehensively.Some mathematical transformations allow PI,LQG,DFF,and DOBC to be described in a uniform framework of sensitivity function that expresses their advantages and disadvantages.In essence,feed forward control based-inverse model is the main idea of current techniques,which is dependent on accuracies of models in terms of Tip-Tilt mirror and vibrations.DOBC can relax dependences on accuracy model,and therefore this survey concentrates on concise tutorials of this method with clear descriptions of their features in the control area of disturbance rejections.Its applications in various conditions are reviewed with emphasis on the effectiveness.Finally,the open problems,challenges and research prospects of DOBC of Tip-Tilt mirror are discussed.
基金supported by the Quantum Communication Project,one of the Strategic Pilot Projects,Chinese Academy of Sciences
文摘In this paper, a cascade acceleration feedback control(AFC) enhanced by a disturbance observation and compensation(DOC) method is proposed to improve the tracking precision of telescope systems.Telescope systems usually suffer some uncertain disturbances, such as wind load, nonlinear friction and other unknown disturbances. To ensure tracking precision, an acceleration feedback loop which can increase the stiffness of such a system is introduced. Moreover, to further improve the tracking precision, we introduce the DOC method which can accurately estimate the disturbance and compensate it. Furthermore,the analysis of tracking accuracy used by this method is proposed. Finally, a few comparative experimental results show that the proposed control method has excellent performance for reducing the tracking error of a telescope system.
基金This study will be supported by grants from the National Natural Science Foundation of China(No.81630080,91129714,81270466,81173424 and 81373796)the Science Research Foundation of BUCM(No.2014-JYBZZ-XS-134)+1 种基金the Research Foundation of the Doctoral Program of Higher Education of China(No.20120013110014)the National Undergraduates Innovating Experimentation Project of the Ministry of Education of China(No.081002609).
文摘Objective:Traditional Chinese medicine(TCM)and modern medicine have both been used in arresting malignant transformation of chronic atrophic gastritis(CAG)in China with good therapeutic effect.However,no studies have been undertaken to assess the risk of malignant transformation in CAG patients using both modern medicine and TCM features.Our study aimed to develop risk assessment models for malignant transformation of CAG combining indicators of both TCM and modern medicine.These models will facilitate early warning and control of malignant transformation of CAG from the perspective of evidence-based integrative medicine.Methods:In the proposed registry study,a total of 1000 eligible CAG patients will be recruited from four hospitals in China.A 10-year follow-up study will be conducted both on-site and off-site to track the events of malignant transformation.Frequency analysis and chi-squared tests will be used to perform the comparative analysis on the prevalence of malignant transformation events and indicators in TCM or modern medicine in different groups.A multivariate Cox proportional hazard model will be used to perform correlation analyses of malignant transformation events and factors of TCM or modern medicine.Conclusion:The proposed study has been designed with a large sample size and long follow-up period,in which wide-ranging modern medicine and TCM indicators can be gathered over the whole process of malignant transformation of CAG.Based on this study,risk assessment models for malignant transformation ofCAGmaybe constructed fromthe perspective of integrative medicine.This may provide clinicians and patients with an optimized early warning system as well as prevention strategies for malignant transformation of CAG.
基金supported by the National Natural Science Foundation of China(No.51903099 and 51991353)Huazhong University of Science and Technology(No.3004013134)the 100 Talents Program of the Hubei Provincial Government,and the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003).
文摘Wood-based bilayer solar evaporators,which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation,low heat conduction,renewability,and high light absorbability,hold great promise for water purification.However,previous studies suffer from low evaporation rates and high cost of coatings,and lack a deep understanding how the porous structures of coating layer function.Herein,a novel bilayer solar evaporator is designed through facile surface coating of wood by low-cost porous carbon from controlled carbonization of polyester waste.The porous carbon bears rich oxygen-containing groups,well-controlled micro-/meso-/macropores,and high surface areas(1164 m^(2) g^(−1)).It is proved that porous carbon improves sunlight absorption and promotes the formation of numerous water clusters to reduce water evaporation enthalpy.Owing to these combined features,the bilayer solar evaporator exhibits high evaporation rate(2.38 kg m^(−2) h^(−1)),excellent longterm stability,and good salt resistance.More importantly,a large-scale solar desalination device for outdoor experiments is developed to produce freshwater from seawater.The daily freshwater production amount(3.65 kg m^(−2))per unit area meets the daily water consumption requirement of one adult.These findings will inspire new paradigms toward developing efficient solar steaming technologies for desalination to address global freshwater shortage.
基金This work was supported by the project of China Geology Survey(DD20190315)Innovation Capability Support Program of Shaanxi(2019TD-040)+1 种基金“Integration of Groundwater Resources Assessment Results in Key Areas of Northwest China”programKey Laboratory of Groundwater and Ecology in Arid and Semi-arid Areas of China Geological Survey.
文摘Glaciers are crucial water resources for arid inland rivers in Northwest China.In recent decades,glaciers are largely experiencing shrinkage under the climate-warming scenario,thereby exerting tremendous influences on regional water resources.The primary role of understudying watershed scale glacier changes under changing climatic conditions is to ensure sustainable utilization of regional water resources,to prevent and mitigate glacier-related disasters.This study maps the current(2020)distribution of glacier boundaries across the Kaidu-Kongque river basin,south slope of Tianshan Mountains,and monitors the spatial evolution of glaciers over five time periods from 2000-2020 through thresholded band ratios approach,using 25 Landsat images at 30 m resolution.In addition,this study attempts to understand the role of climate characteristics for variable response of glacier area.The results show that the total area of glaciers was 398.21 km^(2)in 2020.The glaciers retreated by about 1.17 km^(2)/a(0.26%/a)from 2000 to 2020.The glaciers were reducing at a significantly rapid rate between 2000 and 2005,a slow rate from 2005 to 2015,and an accelerated rate during 2015-2020.The meteorological data shows slight increasing trends of mean annual temperature(0.02℃/a)and annual precipitation(2.07 mm/a).The correlation analysis demonstrates that the role of temperature presents more significant correlation with glacier recession than precipitation.There is a temporal hysteresis in the response of glacier change to climate change.Increasing trend of temperature in summer proves to be the driving force behind the Kaidu-Kongque basin glacier recession during the recent 20 years.
基金supported by the Medical Sciences Foundation of China,No.14CXZ007
文摘Signals from lumbar primary afferent fibers are important for modulating locomotion of the hind-limbs.However,silver impregnation techniques,autoradiography,wheat germ agglutinin-horseradish peroxidase and cholera toxin B subunit-horseradish peroxidase cannot image the central projections and connections of the dorsal root in detail.Thus,we injected 3-k Da Texas red-dextran amine into the proximal trunks of L4 dorsal roots in adult rats.Confocal microscopy results revealed that numerous labeled arborizations and varicosities extended to the dorsal horn from T12–S4,to Clarke's column from T10–L2,and to the ventral horn from L1–5.The labeled varicosities at the L4 cord level were very dense,particularly in laminae I–Ⅲ,and the density decreased gradually in more rostral and caudal segments.In addition,they were predominately distributed in laminae I–IV,moderately in laminae V–VⅡ and sparsely in laminae VⅢ–X.Furthermore,direct contacts of lumbar afferent fibers with propriospinal neurons were widespread in gray matter.In conclusion,the projection and connection patterns of L4 afferents were illustrated in detail by Texas red-dextran amine-dorsal root tracing.
基金supported by the National Natural Science Foundation of China(Nos.50977042 and 10904061)the“863”program of MSTC(No.2006AA03Z458)the research funds for Nanjing Institute of Technology(No.YKJ201002)
文摘A new material is prepared by impregnating the expanded graphite(EG) into ethanol solutions of metal acetate and then drying and reducing it in H2.It contains the EG and the nanoparticles of the magnetic Ni–Fe alloy for the electromagnetic shielding.Its morphology,phase structure,magnetic properties,and electromagnetic shielding effectiveness(SE) are investigated in our experiment.It shows that the morphology,the phase structure,and the magnetic property of the composite can be modified by altering the Ni content in the alloy nanoparticles.Interestingly,the SE can be enhanced to 54–70 d B at low frequencies(300 kHz–10 MHz) by dispersing the magnetic nanoparticles onto EG.
文摘This paper proposes a dual-motor configuration to enhance closed-loop performance of a telescope control system. Two identical motors are mounted on each side of a U-type frame to drive the telescope elevation axis instead of a single motor drive, which is usually used in a classical design. This new configuration and mechanism can reduce the motor to half the size used in the former design, and it also provides some other advantages. A master-slave current control mode is employed to synchronize the two motors. Acceleration feedback control is utilized to further enhance the servo performance. Extensive experiments are used to validate the effectiveness of the proposed control algorithm in synchronization, disturbance attenuation and low-velocity tracking.
基金supported by the National Natural Science Foundation of China(No.51303170)the National Science Centre,Poland within BEETHOVEN UMO-2016/23/G/ST5/04200。
文摘Porous carbon materials have exhibited a series of promising applications in supercapacitors and other research fields,yet still confronting the complicated synthetic procedures and massive usage of toxic reagents.Herein,we propose a green and one-pot method to produce heteroatomdoped hierarchical porous carbon materials in large-scale without any toxic reagents employed.Eventually,the as-prepared nitrogen-doped porous carbon(NPC)displays a high specific surface area of 2018 m^(2)g^(-1)together with abundant heteroatom dopants(14.8 wt%O and 1.03 wt%N).The potassium carbonate template can be recycled via a simple rinsing and re-precipitation process.Furthermore,the as-prepared nitrogen-doped porous carbon delivers a high specific capacitance of 361 F g^(-1)at 0.5 A g^(-1)and excellent rate capability of 240 F g^(-1)at 20 A g^(-1)(66.5%capacitance retention).Finally,considering the low-price raw materials and facile green synthesis procedure,the present approach can be easily scalable to prepare biomass-derived heteroatoms doped porous carbon,which is not only applicable for supercapacitor but also for other research fields.
基金supported by National Natural Science Foundation of China(No.51903099 and 51991353)100 Talents Program of Hubei Provincial Government,Huazhong University of Science and Technology(No.3004013134 and 2021XXJS036)+1 种基金the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003)the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences.
文摘Solar evaporation is recognized as a prospective technique to produce freshwater from non-drinkable water using inexhaustible solar energy.However,it remains a challenge to fabricate low-cost solar evaporators with obviously reduced water evaporation enthalpy to achieve high evaporation rates.Herein,N,O dual-doped carbon foam(NCF)is fabricated from the lowtemperature carbonization of poly(ethylene terephthalate)(PET)waste by melamine/molten salts at 340℃.During carbonization,melamine reacts with carboxylic acids of PET degradation products to yield a crosslinking network,and then molten salts catalyze the decarboxylation and dehydration to construct a stable framework.Owing to rich N,O-containing groups,3D interconnected pores,super-hydrophilicity,and ultra-low thermal conductivity(0.0599 W m^(−1) K^(−1)),NCF not only achieves high light absorbance(ca.99%)and solar-to-thermal conversion,but also promotes the formation of water cluster to reduce water evaporation enthalpy by ca.37%.Consequently,NCF exhibits a high evaporation rate(2.4 kg m^(−2) h^(−1)),surpassing the-state-of-the-art solar evaporators,and presents good antiacid/basic abilities,long-term salt-resistance,and self-cleaning ability.Importantly,a large-scale NCF-based outdoor solar desalination device is developed to produce freshwater.The daily freshwater production amount per unit area(6.3 kg)meets the two adults’daily water consumption.The trash-to-treasure strategy will give impetus to the development of low-cost,advanced solar evaporators from waste plastics for addressing the global freshwater shortage.
文摘The represent paper will study the performance of the power plant with the combination of dry and wet cooling systems in different operating conditions. A thermodynamic performance analysis of the steam cycle system was performed by means of a program code dedicated to power plant modeling in design operating condition. Then the off-design behavior was studied by varying not only the ambient temperature and relative humidity but also several parameters connected to the cooling performance, like the exhaust steam flow rate, the air cooling fan load and the number of operating cooling water pumps and cooling towers. The result is an optimum set of variables allowing the dry and wet cooling system be regulated in such a way that the maximum power is achieved and low water consumption.
基金We acknowledge use of OMNI data obtained from the OMNIWeb service at http://omniweb.gsfc.nasa.gov.We thank the Polar UVI team for providing UV images.The IMAGE FUV data were provided by the NASA Space Science Data Center(NSSDC)This work was supported by the National Natural Science Foundation of China(Grants 41961130382,41731068 and 41941001)+1 种基金the Royal Society NAF\R1\191047,International Space Science Institute(ISSI)the young scholar plan of Shandong University at Weihai(2017WHWLJH08).
文摘Earth’s aurora is a luminescent phenomenon generated by the interaction between magnetospheric precipitating particles and the upper atmosphere;it plays an important role in magnetosphere–ionosphere(M-I)coupling.The transpolar arc(TPA)is a discrete auroral arc distributed in the noon-midnight direction poleward of the auroral oval and connects the dayside to the nightside sectors of the auroral oval.Studying the seasonal variation of TPA events can help us better understand the long-term variation of the interaction between the solar wind,the magnetosphere,and M-I coupling.However,a statistical study of the seasonal variation of TPA incidence has not previously been carried out.In this paper,we have identified 532 TPA events from the IMAGE database(2000–2005)and the Polar database(1996–2002),and calculated the incidence of TPA events for different months.We find a semiannual variation in TPA incidence.Clear peaks in the incidence of TPAs occur in March and September;a less pronounced peak appears in November.We also examine seasonal variation in the northward interplanetary magnetic field(IMF)over the same time period.The intensity and occurrence rate of the northward IMF exhibit patterns similar to that of the TPA incidence.Having studied IMF Bz before TPA onset,we find that strong and steady northward IMF conditions are favorable for TPA formation.We suggest that the semiannual variation observed in TPA incidence may be related to the Russell–McPherron(R-M)effect due to the projection effect of the IMF By under northward IMF conditions.
文摘A simple theoretical modeling is made to describe the reflection features of the high power microwave (HPM) in the mixture-atmosphere. The time-space dependent mixture-atmosphere is generated by ionization of the neutral molecules in atmosphere. Reflection will occur when HPM propagates in such mixture-atmosphere. The reflection characteristic of the HPM propagation in the mixture-atmosphere is investigated by FDTD numerical experiments in inhomogeneous medium, the influence on the reflection for different HPM parameters is concluded. An additional stability conditions for the FDTD difference scheme of the HPM mixture-atmosphere propagation model are presented.