There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and ...There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and Western countries.The Chinese Society of Clinical Oncology(CSCO)has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually.Taking into account regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China.The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis,treatment,follow-up,and screening of gastric cancer.Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines,this updated guideline integrates the results ofmajor clinical studies from China and overseas for the past year,focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations.For the comprehensive treatment of non-metastatic gastric cancer,attentions were paid to neoadjuvant treatment.The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated.For the comprehensive treatment of metastatic gastric cancer,recommendations for immunotherapy were included,and immune checkpoint inhibitors fromthird-line to the first-line of treatment for different patient groups with detailed notes are provided.展开更多
The understanding of Goss texture in Hi-B electrical steels possesses significant industrial and academic value, thus attracts worldwide attention. The prevailing models for sharp Goss texture formation during seconda...The understanding of Goss texture in Hi-B electrical steels possesses significant industrial and academic value, thus attracts worldwide attention. The prevailing models for sharp Goss texture formation during secondary recrystallization are CSL （coincident site lattice） boundary theory and HE （high energy） boundary theory. These theories stress the key factor of preferred growth and the difference between them only lies in the specific selection manner. This work examined the texture gradient in primarily recrystallized sheet and demonstrated its possible influence on the formation of secondary grains, and then determined the micro- texture during different stages of secondary recrystallization using EI3SD （electron back-scattered diffraction） technique, finally analyzed a special type of secondary grains with near Brass orientation, which were detected in the later stage of secondary recrystallization, and discussed its origin and effect in terms of surface energy effect. The results indicate that texture gradient in primarily recrystallized sheet will lead to a multi-stage formation of Goss texture, namely, early stage of secondary grains with various orientations in subsurface region, intermediate stage of preferred growth of Goss grains into center layer and re-grow back to the surface and the final stage of Goss grain growth by swallowing slowly the island grains with the help of H2 atmosphere.展开更多
The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble die...The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.展开更多
Terahertz(THz)technology offers novel opportunities in biology and medicine,thanks to the unique features of THzwave interactions with tissues and cells.Among them,we particularly notice strong sensitivity of THz wave...Terahertz(THz)technology offers novel opportunities in biology and medicine,thanks to the unique features of THzwave interactions with tissues and cells.Among them,we particularly notice strong sensitivity of THz waves to the tissue water,as a medium for biochemical reactions and a main endogenous marker for THz spectroscopy and imaging.Tissues of the brain have an exceptionally high content of water.This factor,along with the features of the structural organization and biochemistry of neuronal and glial tissues,makes the brain an exciting subject to study in the THz range.In this paper,progress and prospects of THz technology in neurodiagnostics are overviewed,including diagnosis of neurodegenerative disease,myelin deficit,tumors of the central nervous system(with an emphasis on brain gliomas),and traumatic brain injuries.Fundamental and applied challenges in study of the THz-wave–brain tissue interactions and development of the THz biomedical tools and systems for neurodiagnostics are discussed.展开更多
Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which ...Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which enhanced whistler mode waves(~10^(−11) V^(2)/m^(2)/Hz)with frequency of 0.1 f_(ce)-0.5 f_(ce) occurred,based on MAVEN data,exactly corresponding to a significant decrease of suprathermal electron fluxes.The diffusion coefficients are calculated by using the observed electric field wave spectra.The pitch angle diffusion coefficient can approach 10^(−2) s^(−1),which is much larger,by~100 times,than the momentum diffusion coefficient,indicating that pitch angle scattering dominates the whistler-electron resonance process.The current results can successfully explain the dropout of the suprathermal electrons in this event.This study provides direct evidence for whistler-driven electron losses in the Martian magnetosphere.展开更多
Dear Editor,The X-linked gene cyclin-dependent kinase-like 5(CDKL5)encodes a serine/threonine kinase that is associated with CDKL5-deficiency disorder(CDD),a severe developmental and epileptic encephalopathy character...Dear Editor,The X-linked gene cyclin-dependent kinase-like 5(CDKL5)encodes a serine/threonine kinase that is associated with CDKL5-deficiency disorder(CDD),a severe developmental and epileptic encephalopathy characterized by early-onset seizures,gross developmental delay,and motor disabilities[1].The expression of CDKL5 is highly enriched in the brain and is significantly induced during postnatal development[2].展开更多
Dear Editor,This letter focuses on the problem of remaining useful life(RUL)prediction of equipment. Existing graph neural network(GCN)-based approaches merely provide the point estimation of RUL. However,the estimate...Dear Editor,This letter focuses on the problem of remaining useful life(RUL)prediction of equipment. Existing graph neural network(GCN)-based approaches merely provide the point estimation of RUL. However,the estimated RUL often varies widely due to the model parameters and the noise in data. It is important to know the uncertainty in predictions for reliable risk analysis and maintenance decision making.To map the relationship between noisy condition monitoring data and RUL with uncertainty.展开更多
High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture （{ [10}（001）） of grain oriented （GO） silicon steel...High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture （{ [10}（001）） of grain oriented （GO） silicon steel during secondary recrystallization process, an in situ experiment using hi gh energy X-ray diffraction was designed. The results showed that the secondary recrystallization began when the heating temperature was 1,494 K, and the grains grew rapidly above this temperature. With an increase in annealing temperature, the large grains with 7 orientation [〈111〉//normal direction] formed and gradually occupied the dominant position. As the annealing temperature increased even further, the grains with Goss orientation to a very large size by devouring the 7 orientation grains that formed in the early annealing stage. A single crystal with a Goss orientation was observed in the GO silicon steel when the annealing temperature was 1,540 K.展开更多
Spinal muscular atrophy （SMA） is a genetic neuromuscular disorder characterized by progressive degeneration of the anterior horn cell leading to a lower motor neuron lesion. It is characterized by degeneration of a...Spinal muscular atrophy （SMA） is a genetic neuromuscular disorder characterized by progressive degeneration of the anterior horn cell leading to a lower motor neuron lesion. It is characterized by degeneration of alpha neurons in the anterior horn cells of the spinal cord leading to progressive muscle atrophy and premature death, usually from respiratory failure.1 There are four types according to the symptoms （Table 1）.展开更多
BACKGROUND Endoscopic submucosal dissection(ESD)is an established technique for the treatment of early gastrointestinal neoplasia.Generally,multi-day(M-D)admission is required for patients undergoing ESD due to potent...BACKGROUND Endoscopic submucosal dissection(ESD)is an established technique for the treatment of early gastrointestinal neoplasia.Generally,multi-day(M-D)admission is required for patients undergoing ESD due to potential complications.AIM To evaluate the feasibility of a same-day(S-D)discharge strategy for ESD of the esophagus or stomach.METHODS The data of patients who underwent esophageal or gastric ESD were retrospectively collected from January 2018 to December 2021 at Peking University Cancer Hospital.The propensity score matching(PSM)method was applied to balance the unevenly distributed patient baseline characteristics between the S-D and M-D groups.Intraoperative and postoperative parameters were compared between the matched groups.RESULTS Among the 479 patients reviewed,470 patients,including 91 in the S-D group and 379 in the M-D group,fulfilled the inclusion and exclusion criteria.Following PSM,78 patients in each group were paired using the 1:1 nearest available score match algorithm.No significant difference was found between groups with respect to intraoperative and postprocedural major adverse events(AEs).Tumor size,complete resection rate,and procedural duration were comparable between the groups.The S-D group demonstrated a significantly shorter length of hospital stay(P<0.001)and lower overall medical expenses(P<0.001)compared with the M-D group.CONCLUSION The S-D discharge strategy may be feasible and effective for esophagogastric ESD,and the procedural-related AEs can be managed successfully.展开更多
Metasurfaces have powerful light field manipulation capabilities and have been researched and developed extensively in various fields.With an increasing demand for diverse functionalities,terahertz(THz)metasurfaces ar...Metasurfaces have powerful light field manipulation capabilities and have been researched and developed extensively in various fields.With an increasing demand for diverse functionalities,terahertz(THz)metasurfaces are also expanding their domain.In particular,integrating different functionalities into a single device is a compelling domain in metasurfaces.In this work,we demonstrate a functionally decoupled THz metasurface that can incorporate any two functions into one metasurface and switch dynamically through external excitation.This proposed metasurface is formed by the combination of split-ring resonators and phase change material vanadium dioxide(VO_(2)).It operates in the single-ring resonant mode and double-ring resonant mode with varying VO_(2)in insulating and metallic states,respectively.More importantly,the phase modulation is independent in two operating modes,and both cover a 360°cross-polarized phase with efficient polarization conversion.This characteristic makes it obtain arbitrary independent phase information on the metasurface with different modes to switch dual functions dynamically.Here,we experimentally demonstrate the functions of a tunable focal length and large-angle focus deflection of a THz off-axis parabolic mirror to verify the dual-function switching characteristics of the functionally decoupled metasurface.The functionally decoupled metasurface developed in this work broadens the way for the research and application of multifunctional modulation devices in the THz band.展开更多
The cold rolling deformation textural evolution of an interstitial-free （IF） steel sheet is investigated by experiment and simulation. The microstructure of the IF steel is observed by transmission electron microsco...The cold rolling deformation textural evolution of an interstitial-free （IF） steel sheet is investigated by experiment and simulation. The microstructure of the IF steel is observed by transmission electron microscopy （TEM）. The relationship between the deformation behavior of individual grain and the grain orientation are connected by Taylor factor M. The results show that the grains with higher Taylor factor are deformed slighter than those with lower ones. By considering the heterogeneous deformation, the texture simulation result can be greatly improved.展开更多
We study the field-aligned propagating magnetospheric chorus wave instability using a fully relativistic wave growth formula,the previously developed relativistic Kappa-type(KT) distribution and the regular Kappa dist...We study the field-aligned propagating magnetospheric chorus wave instability using a fully relativistic wave growth formula,the previously developed relativistic Kappa-type(KT) distribution and the regular Kappa distribution of energetic electrons.We demonstrate that the peak growth rate using the nonrelativistic Kappa simulation is higher than that using either the relativistic KT or the Kappa simulation at/above 100 keV, because the significant relativistic effect yields a reduction in the relativistic anisotropy. The relativistic anisotropy Arel basically decreases as the thermal parameter θ2 increases, allowing the peak growth by relativistic KT or Kappa distribution to stay at the lower frequency region. The growth rates tend to increase with the loss-cone parameter l because the overall anisotropy increases. Moreover, at high energy ~1.0 MeV, both the growth rate and the upper cutoff frequency become smaller as l increases for the relativistic KT calculation because the significant relativistic effect reduces both the resonant anisotropy and the number of the hot electrons, which is in contrast to the relativistic and nonrelativistic Kappa distribution calculations because the less relativistic or non-relativistic effect enhances the resonant anisotropy as l increases. The above results can be applied to the whistler-mode wave instability in the outer radiation belts of the Earth, the Jovian inner magnetosphere and other astrophysical plasmas where relativistic electrons often exist.展开更多
With the worldwide development of nuclear power plant and requirement of saving energy and resource, high thermal efficiency and economical competitiveness are achieved by using supercritical COR2R with spe-cial therm...With the worldwide development of nuclear power plant and requirement of saving energy and resource, high thermal efficiency and economical competitiveness are achieved by using supercritical COR2R with spe-cial thermal properties and better flow and heat transfer characters. In this paper, heat transfer of supercritical COR2R has been investigated in square and triangle array tube-bundle of cooled system in reactor using com-putational fluid dynamics (CFD) code FLUENT, and the basic knowledge of heat transfer of supercritical COR2R and first experience of CFD simulation are obtained. The effect of mesh structures, turbulence models, as well as flow channel size is analyzed. The choice of turbulence model adopted in simulating supercritical COR2R is recommended. Comparing the effect of heat transfer with supercritical COR2R and supercritical water as cooled medium, the results show that the former was higher. The new idea is provided for choice of cooled medium and improving thermal efficiency this paper.展开更多
With the enhancement of environmental protection consciousness,concerns have been raised about non-toxic and biodegradable leather retanning agents.According to the European standard 2002/231/EC,the free formaldehyde ...With the enhancement of environmental protection consciousness,concerns have been raised about non-toxic and biodegradable leather retanning agents.According to the European standard 2002/231/EC,the free formaldehyde content of leather products should be less than 150 mg/kg.As one of the retanning agents in the market,the content of free formaldehyde in the Multifunctional retanning agent(MTA)is 372.22 mg/kg and higher than the limit value.In this work,glutaraldehyde as an alternative of formaldehyde was used to modify acrylic polymer and an amphoteric acrylic retanning agent was prepared.Then it was used in retanning process,and its retanning and assistant-dyeing properties were investigated.The results showed that the free formaldehyde content of amphoteric acrylic retanning agent modified with glutaraldehyde was only 4.17mg/kg.Meanwhile,the presence of amino groups in the amphoteric acrylic retanning agent improved the dyeing properties of leather by electrostatic attraction.Compared with the leather treated with anionic acrylic retanning agent,the residual dye concentration of the dyeing effluent of the retanned leather with amphoteric acrylic retanning agent decreased from 17.4mg/L to 10.0mg/L,and the dyed leather had better resistances to friction and water-washing.In addition,the BOD 5/COD value of the wastewater after Mannich base polymer retanning was only 0.32,indicating that the retanning agent was biodegradable.Moreover,the leather retanned with amphoteric acrylic retanning agent had good thermal stability,fullness and physical and mechanical properties.展开更多
Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactio...Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.展开更多
Polymer thermal recycling for hydrogen production is a promising process to recover such precious element from plastic waste. In the present work a simple but efficacious high energy milling pretreatment is proposed t...Polymer thermal recycling for hydrogen production is a promising process to recover such precious element from plastic waste. In the present work a simple but efficacious high energy milling pretreatment is proposed to boost H2 generation during polyethylene gasification. The polymer is comilled with calcium and nickel hydroxides and then it is subjected to thermal treatment. Results demonstrate the key role played by the calcium hydroxide that significantly ameliorates hydrogen production. It reacts in solid state with the polyethylene to fonn directly carbonate and hydrogen. In this way, the CO2 is immediately captured in solid fonn, thus shifting the equilibrium toward H2 generation and obtaining high production rate (>25 L/mol CH2). In addition, high amounts of the hydroxide prevent excessive methane fonnation, so the gas product is almost pure hydrogen (~95%).展开更多
Three polymerizable vinyl guaifenesin esters with different acyl donor carbon chain lengths (C4,C6,C10) were regioselectivly synthesized by an alkaline protease from Bacillus subtilis in pyridine at 50C for 1, 3, 5 da...Three polymerizable vinyl guaifenesin esters with different acyl donor carbon chain lengths (C4,C6,C10) were regioselectivly synthesized by an alkaline protease from Bacillus subtilis in pyridine at 50C for 1, 3, 5 days respectively.展开更多
Taxonomic bias is a well-known shortcoming of species occurrence databases.Understanding the causes of taxonomic bias facilitates future biological surveys and addresses current knowledge gaps.Here,we investigate the ...Taxonomic bias is a well-known shortcoming of species occurrence databases.Understanding the causes of taxonomic bias facilitates future biological surveys and addresses current knowledge gaps.Here,we investigate the main drivers of taxonomic bias in occurrence data of angiosperm species in China.We used a database including 5,936,768 records for 28,968 angiosperm species derived from herbarium specimens and literature sources.Generalized additive models(GAMs)were applied to investigate explanatory powers of 17 variables on the variation in record numbers of species.Five explanatory variables were selected for a multi-predictor GAM that explained 69%of the variation in record numbers:plant height,range size,elevational range,numbers of scientific publications and web pages.Range size was the most important predictor in the model and positively correlated with number of records.Morphological and phenological traits and social-economic factors including economic values and conservation status had weak explanatory powers on record numbers of plant species,which differs from the findings in animals,suggesting that causes of taxonomic bias in occurrence databases may vary between taxonomic groups.Our results suggest that future floristic surveys in China should more focus on range-restricted and socially or scientifically less"interesting"species.展开更多
In this paper, we propose a new multicast wavelength assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated int...In this paper, we propose a new multicast wavelength assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated into two phases: the partial wavelength assignment phase and the complete wavelength assignment phase. It tries to minimize the total number of wavelength conversions of the multicast tree. Meanwhile, the number of different wavelengths used is minimized locally. Through illustrative example and simulation experiments, it is proved that the NGWA algorithm works well and achieves satisfactory performance in terms of the average number of wavelength conversions and the average blocking probability.展开更多
文摘There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and Western countries.The Chinese Society of Clinical Oncology(CSCO)has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually.Taking into account regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China.The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis,treatment,follow-up,and screening of gastric cancer.Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines,this updated guideline integrates the results ofmajor clinical studies from China and overseas for the past year,focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations.For the comprehensive treatment of non-metastatic gastric cancer,attentions were paid to neoadjuvant treatment.The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated.For the comprehensive treatment of metastatic gastric cancer,recommendations for immunotherapy were included,and immune checkpoint inhibitors fromthird-line to the first-line of treatment for different patient groups with detailed notes are provided.
基金supported by the National Natural Science Foundation of China under Grant No. 51071024
文摘The understanding of Goss texture in Hi-B electrical steels possesses significant industrial and academic value, thus attracts worldwide attention. The prevailing models for sharp Goss texture formation during secondary recrystallization are CSL （coincident site lattice） boundary theory and HE （high energy） boundary theory. These theories stress the key factor of preferred growth and the difference between them only lies in the specific selection manner. This work examined the texture gradient in primarily recrystallized sheet and demonstrated its possible influence on the formation of secondary grains, and then determined the micro- texture during different stages of secondary recrystallization using EI3SD （electron back-scattered diffraction） technique, finally analyzed a special type of secondary grains with near Brass orientation, which were detected in the later stage of secondary recrystallization, and discussed its origin and effect in terms of surface energy effect. The results indicate that texture gradient in primarily recrystallized sheet will lead to a multi-stage formation of Goss texture, namely, early stage of secondary grains with various orientations in subsurface region, intermediate stage of preferred growth of Goss grains into center layer and re-grow back to the surface and the final stage of Goss grain growth by swallowing slowly the island grains with the help of H2 atmosphere.
基金financially supported by the National Key Technology R&D Program in the 11th Five Yr Plan of China(2006BAD12B01)Special Public Sector Fund in Agriculture(200903006)
文摘The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.
基金The work was supported by the Russian Science Foundation,Project#22-22-00596.
文摘Terahertz(THz)technology offers novel opportunities in biology and medicine,thanks to the unique features of THzwave interactions with tissues and cells.Among them,we particularly notice strong sensitivity of THz waves to the tissue water,as a medium for biochemical reactions and a main endogenous marker for THz spectroscopy and imaging.Tissues of the brain have an exceptionally high content of water.This factor,along with the features of the structural organization and biochemistry of neuronal and glial tissues,makes the brain an exciting subject to study in the THz range.In this paper,progress and prospects of THz technology in neurodiagnostics are overviewed,including diagnosis of neurodegenerative disease,myelin deficit,tumors of the central nervous system(with an emphasis on brain gliomas),and traumatic brain injuries.Fundamental and applied challenges in study of the THz-wave–brain tissue interactions and development of the THz biomedical tools and systems for neurodiagnostics are discussed.
基金the National Natural Science Foundation of China grants 42230209, 42241136, 42374199, 42204171, 42274212the Natural Science Foundation of Hunan province Grant 2021JJ20010, 2023JJ20038
文摘Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which enhanced whistler mode waves(~10^(−11) V^(2)/m^(2)/Hz)with frequency of 0.1 f_(ce)-0.5 f_(ce) occurred,based on MAVEN data,exactly corresponding to a significant decrease of suprathermal electron fluxes.The diffusion coefficients are calculated by using the observed electric field wave spectra.The pitch angle diffusion coefficient can approach 10^(−2) s^(−1),which is much larger,by~100 times,than the momentum diffusion coefficient,indicating that pitch angle scattering dominates the whistler-electron resonance process.The current results can successfully explain the dropout of the suprathermal electrons in this event.This study provides direct evidence for whistler-driven electron losses in the Martian magnetosphere.
基金This work was supported by the Ministry of Science and Technology(2018YFA0801404)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX05).
文摘Dear Editor,The X-linked gene cyclin-dependent kinase-like 5(CDKL5)encodes a serine/threonine kinase that is associated with CDKL5-deficiency disorder(CDD),a severe developmental and epileptic encephalopathy characterized by early-onset seizures,gross developmental delay,and motor disabilities[1].The expression of CDKL5 is highly enriched in the brain and is significantly induced during postnatal development[2].
基金supported by the Major Special Program of Chongqing Science&Technology Commission(CSTC 2019jscx-zdztzx X0031)Graduate Scientific Research and Innovation Foundation of Chongqing(CYB21068,CYS22128)。
文摘Dear Editor,This letter focuses on the problem of remaining useful life(RUL)prediction of equipment. Existing graph neural network(GCN)-based approaches merely provide the point estimation of RUL. However,the estimated RUL often varies widely due to the model parameters and the noise in data. It is important to know the uncertainty in predictions for reliable risk analysis and maintenance decision making.To map the relationship between noisy condition monitoring data and RUL with uncertainty.
基金supported by the Key Projects of the National Science & Technology Pillar Program (No. 2011BAE13B03)the Fundamental Research Funds for the Central Universities (No. N110502001)
文摘High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture （{ [10}（001）） of grain oriented （GO） silicon steel during secondary recrystallization process, an in situ experiment using hi gh energy X-ray diffraction was designed. The results showed that the secondary recrystallization began when the heating temperature was 1,494 K, and the grains grew rapidly above this temperature. With an increase in annealing temperature, the large grains with 7 orientation [〈111〉//normal direction] formed and gradually occupied the dominant position. As the annealing temperature increased even further, the grains with Goss orientation to a very large size by devouring the 7 orientation grains that formed in the early annealing stage. A single crystal with a Goss orientation was observed in the GO silicon steel when the annealing temperature was 1,540 K.
文摘Spinal muscular atrophy （SMA） is a genetic neuromuscular disorder characterized by progressive degeneration of the anterior horn cell leading to a lower motor neuron lesion. It is characterized by degeneration of alpha neurons in the anterior horn cells of the spinal cord leading to progressive muscle atrophy and premature death, usually from respiratory failure.1 There are four types according to the symptoms （Table 1）.
基金Wu Jie-Ping Medical Foundation Special Fund for Clinical Research,No.320.6750.2021-04-71Open Research Fund of NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases,No.KF202101+3 种基金Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences,No.2020-PT330-003Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support,No.XMLX202143Capital’s Funds for Health Improvement and Research,No.2020-2-2155Beijing Municipal Administration of Hospitals Incubating Program,No.PX2020047.
文摘BACKGROUND Endoscopic submucosal dissection(ESD)is an established technique for the treatment of early gastrointestinal neoplasia.Generally,multi-day(M-D)admission is required for patients undergoing ESD due to potential complications.AIM To evaluate the feasibility of a same-day(S-D)discharge strategy for ESD of the esophagus or stomach.METHODS The data of patients who underwent esophageal or gastric ESD were retrospectively collected from January 2018 to December 2021 at Peking University Cancer Hospital.The propensity score matching(PSM)method was applied to balance the unevenly distributed patient baseline characteristics between the S-D and M-D groups.Intraoperative and postoperative parameters were compared between the matched groups.RESULTS Among the 479 patients reviewed,470 patients,including 91 in the S-D group and 379 in the M-D group,fulfilled the inclusion and exclusion criteria.Following PSM,78 patients in each group were paired using the 1:1 nearest available score match algorithm.No significant difference was found between groups with respect to intraoperative and postprocedural major adverse events(AEs).Tumor size,complete resection rate,and procedural duration were comparable between the groups.The S-D group demonstrated a significantly shorter length of hospital stay(P<0.001)and lower overall medical expenses(P<0.001)compared with the M-D group.CONCLUSION The S-D discharge strategy may be feasible and effective for esophagogastric ESD,and the procedural-related AEs can be managed successfully.
基金National Key Research and Development Program of China(2021YFB1401000,2018YFB1801503)National Natural Science Foundation of China(62101111,61931006,U20A20212,61901093,61871419,61771327,61921002)+1 种基金Sichuan Science and Technology Program(2020JDRC0028)China Postdoctoral Science Foundation(2020M683285)。
文摘Metasurfaces have powerful light field manipulation capabilities and have been researched and developed extensively in various fields.With an increasing demand for diverse functionalities,terahertz(THz)metasurfaces are also expanding their domain.In particular,integrating different functionalities into a single device is a compelling domain in metasurfaces.In this work,we demonstrate a functionally decoupled THz metasurface that can incorporate any two functions into one metasurface and switch dynamically through external excitation.This proposed metasurface is formed by the combination of split-ring resonators and phase change material vanadium dioxide(VO_(2)).It operates in the single-ring resonant mode and double-ring resonant mode with varying VO_(2)in insulating and metallic states,respectively.More importantly,the phase modulation is independent in two operating modes,and both cover a 360°cross-polarized phase with efficient polarization conversion.This characteristic makes it obtain arbitrary independent phase information on the metasurface with different modes to switch dual functions dynamically.Here,we experimentally demonstrate the functions of a tunable focal length and large-angle focus deflection of a THz off-axis parabolic mirror to verify the dual-function switching characteristics of the functionally decoupled metasurface.The functionally decoupled metasurface developed in this work broadens the way for the research and application of multifunctional modulation devices in the THz band.
基金the National Natural Science Foundation of China （Grant No. 50671021） Program for New Century Excellent Talents in University （Grant No. NCET-06-0287）.
文摘The cold rolling deformation textural evolution of an interstitial-free （IF） steel sheet is investigated by experiment and simulation. The microstructure of the IF steel is observed by transmission electron microscopy （TEM）. The relationship between the deformation behavior of individual grain and the grain orientation are connected by Taylor factor M. The results show that the grains with higher Taylor factor are deformed slighter than those with lower ones. By considering the heterogeneous deformation, the texture simulation result can be greatly improved.
基金supported by the National Natural Science Foundation of China(Grant Nos.41531072,41274165,41404130,41204114&41504125)
文摘We study the field-aligned propagating magnetospheric chorus wave instability using a fully relativistic wave growth formula,the previously developed relativistic Kappa-type(KT) distribution and the regular Kappa distribution of energetic electrons.We demonstrate that the peak growth rate using the nonrelativistic Kappa simulation is higher than that using either the relativistic KT or the Kappa simulation at/above 100 keV, because the significant relativistic effect yields a reduction in the relativistic anisotropy. The relativistic anisotropy Arel basically decreases as the thermal parameter θ2 increases, allowing the peak growth by relativistic KT or Kappa distribution to stay at the lower frequency region. The growth rates tend to increase with the loss-cone parameter l because the overall anisotropy increases. Moreover, at high energy ~1.0 MeV, both the growth rate and the upper cutoff frequency become smaller as l increases for the relativistic KT calculation because the significant relativistic effect reduces both the resonant anisotropy and the number of the hot electrons, which is in contrast to the relativistic and nonrelativistic Kappa distribution calculations because the less relativistic or non-relativistic effect enhances the resonant anisotropy as l increases. The above results can be applied to the whistler-mode wave instability in the outer radiation belts of the Earth, the Jovian inner magnetosphere and other astrophysical plasmas where relativistic electrons often exist.
文摘With the worldwide development of nuclear power plant and requirement of saving energy and resource, high thermal efficiency and economical competitiveness are achieved by using supercritical COR2R with spe-cial thermal properties and better flow and heat transfer characters. In this paper, heat transfer of supercritical COR2R has been investigated in square and triangle array tube-bundle of cooled system in reactor using com-putational fluid dynamics (CFD) code FLUENT, and the basic knowledge of heat transfer of supercritical COR2R and first experience of CFD simulation are obtained. The effect of mesh structures, turbulence models, as well as flow channel size is analyzed. The choice of turbulence model adopted in simulating supercritical COR2R is recommended. Comparing the effect of heat transfer with supercritical COR2R and supercritical water as cooled medium, the results show that the former was higher. The new idea is provided for choice of cooled medium and improving thermal efficiency this paper.
基金The financial support of this study was from the Key Program of National Natural Science Foundation of China(No.21838007)National Natural Science Foundation of China(No.21706151).
文摘With the enhancement of environmental protection consciousness,concerns have been raised about non-toxic and biodegradable leather retanning agents.According to the European standard 2002/231/EC,the free formaldehyde content of leather products should be less than 150 mg/kg.As one of the retanning agents in the market,the content of free formaldehyde in the Multifunctional retanning agent(MTA)is 372.22 mg/kg and higher than the limit value.In this work,glutaraldehyde as an alternative of formaldehyde was used to modify acrylic polymer and an amphoteric acrylic retanning agent was prepared.Then it was used in retanning process,and its retanning and assistant-dyeing properties were investigated.The results showed that the free formaldehyde content of amphoteric acrylic retanning agent modified with glutaraldehyde was only 4.17mg/kg.Meanwhile,the presence of amino groups in the amphoteric acrylic retanning agent improved the dyeing properties of leather by electrostatic attraction.Compared with the leather treated with anionic acrylic retanning agent,the residual dye concentration of the dyeing effluent of the retanned leather with amphoteric acrylic retanning agent decreased from 17.4mg/L to 10.0mg/L,and the dyed leather had better resistances to friction and water-washing.In addition,the BOD 5/COD value of the wastewater after Mannich base polymer retanning was only 0.32,indicating that the retanning agent was biodegradable.Moreover,the leather retanned with amphoteric acrylic retanning agent had good thermal stability,fullness and physical and mechanical properties.
基金National Natural Science Foundation of China(grant no.30600070)the National Basic Research program of China(grant no.2005CB422005).
文摘Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.
文摘Polymer thermal recycling for hydrogen production is a promising process to recover such precious element from plastic waste. In the present work a simple but efficacious high energy milling pretreatment is proposed to boost H2 generation during polyethylene gasification. The polymer is comilled with calcium and nickel hydroxides and then it is subjected to thermal treatment. Results demonstrate the key role played by the calcium hydroxide that significantly ameliorates hydrogen production. It reacts in solid state with the polyethylene to fonn directly carbonate and hydrogen. In this way, the CO2 is immediately captured in solid fonn, thus shifting the equilibrium toward H2 generation and obtaining high production rate (>25 L/mol CH2). In addition, high amounts of the hydroxide prevent excessive methane fonnation, so the gas product is almost pure hydrogen (~95%).
文摘Three polymerizable vinyl guaifenesin esters with different acyl donor carbon chain lengths (C4,C6,C10) were regioselectivly synthesized by an alkaline protease from Bacillus subtilis in pyridine at 50C for 1, 3, 5 days respectively.
基金supported by the National Natural Science Foundation of China(41967055,41561097)。
文摘Taxonomic bias is a well-known shortcoming of species occurrence databases.Understanding the causes of taxonomic bias facilitates future biological surveys and addresses current knowledge gaps.Here,we investigate the main drivers of taxonomic bias in occurrence data of angiosperm species in China.We used a database including 5,936,768 records for 28,968 angiosperm species derived from herbarium specimens and literature sources.Generalized additive models(GAMs)were applied to investigate explanatory powers of 17 variables on the variation in record numbers of species.Five explanatory variables were selected for a multi-predictor GAM that explained 69%of the variation in record numbers:plant height,range size,elevational range,numbers of scientific publications and web pages.Range size was the most important predictor in the model and positively correlated with number of records.Morphological and phenological traits and social-economic factors including economic values and conservation status had weak explanatory powers on record numbers of plant species,which differs from the findings in animals,suggesting that causes of taxonomic bias in occurrence databases may vary between taxonomic groups.Our results suggest that future floristic surveys in China should more focus on range-restricted and socially or scientifically less"interesting"species.
文摘In this paper, we propose a new multicast wavelength assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated into two phases: the partial wavelength assignment phase and the complete wavelength assignment phase. It tries to minimize the total number of wavelength conversions of the multicast tree. Meanwhile, the number of different wavelengths used is minimized locally. Through illustrative example and simulation experiments, it is proved that the NGWA algorithm works well and achieves satisfactory performance in terms of the average number of wavelength conversions and the average blocking probability.
