The high-intensity heavy-ion accelerator facility(HIAF)is under design at the Institute of Modern Physics(IMP)and will provide an intense ion beam for nuclear physics,atomic mass measurement research,and other applica...The high-intensity heavy-ion accelerator facility(HIAF)is under design at the Institute of Modern Physics(IMP)and will provide an intense ion beam for nuclear physics,atomic mass measurement research,and other applications.As the main ring of HIAF,the BRing accumulates beams to high intensity and accelerates them to high energy.To achieve high intensities up to 1×10^(11)(^(238)U^(34+)),the injection gain of the BRing must be as high as 88.However,multiple multiturn injection supported by the electron cooling system takes a long time,causing substantial beam loss under a strong space charge effect.Hence,a two-plane painting injection scheme is proposed for beam accumulation in the BRing.This scheme uses a tilted injection septum and horizontal and vertical bump magnets to paint the beam into horizontal and vertical phase space simultaneously.In this paper,the two-plane painting injection parameters are optimized,and the resulting injection process is simulated using the Objective Ring Beam Injection and Tracking(ORBIT)code.An injection gain of up to 110.3 with a loss rate of 2:3%is achieved,meeting the requirements of BRing.展开更多
Shunt dysfunction is a major complication of transjugular intrahepatic portosystemic shunt(TIPS). Ultrasonography is a preferred method of shunt follow-up after TIPS, but some misjudgments can occur in cases of shunt ...Shunt dysfunction is a major complication of transjugular intrahepatic portosystemic shunt(TIPS). Ultrasonography is a preferred method of shunt follow-up after TIPS, but some misjudgments can occur in cases of shunt dysfunction due to peculiarities of the VIATORR stent. Here we report one case and suggest that the first ultrasound evaluation for patients who received TIPS procedure with VIATORR stent should be performed one month after the procedure.展开更多
Objective: To determine the efficacy in treatment of vertically unstable sacral fractures with pelvic external fixation and skeletal traction. Patients and Methods: The pelvic external fixation and skeletal traction w...Objective: To determine the efficacy in treatment of vertically unstable sacral fractures with pelvic external fixation and skeletal traction. Patients and Methods: The pelvic external fixation and skeletal traction were applied on 12 cases of vertically unstable sacral fracture (eight males and four females, at age of 19 - 52 years, mean 35.2 years) including two cases of Denis Zone I, nine of Zone II, and one of Zone III. All patients were treated with the pelvic external fixation, and pre- and post-operational longitudinal skeletal traction. Results: The mean operation time, skeletal traction time, skeletal traction removal time and full weight bearing time were 38 min, 4.5 weeks, 8.5 weeks, and 10.3 weeks respectively. All these patients were followed up for 12 - 36 months (average, 22.5 months), which showed no associated complication. The function results were rated as excellent in four cases, good in six and fair in two, with a mean score of 84.4 points, according to Majeed scoring system. Conclusion: The anterior pelvic external fixation with continuous skeletal traction can reliably restore and stabilize the vertically unstable sacrum fracture with excellent functional and radiographic outcomes. It is an ideal method to treat unstably vertical sacral fracture.展开更多
A 53.667 MHz CW(continuous-wave) heavy ion IH-DTL has been designed for the SSC-LINAC injector of HIRFL-CSR(Heavy Ions Research Facility at Lanzhou-Cooling Storage Ring). It accelerates ions with maximum mass-to-charg...A 53.667 MHz CW(continuous-wave) heavy ion IH-DTL has been designed for the SSC-LINAC injector of HIRFL-CSR(Heavy Ions Research Facility at Lanzhou-Cooling Storage Ring). It accelerates ions with maximum mass-to-charge ratio of 7.0 from 143 to 295 ke V/u. Low-power RF measurement of the IH-DTL1 has been taken to investigate the RF performance and the quality of the electric field distribution on the beam axis.The measured Q_0 value and the shunt impedance are 10,400 and 198 MX/m, respectively. The electric field distributions on and around the beam axis were evaluated and compared with the design value. By a new approach,the dipole field component is also estimated. The beam dynamics simulation using measured field distribution was presented in this paper. Based on the dynamics analysis in both transverse and longitudinal phase space, the field distribution can meet the design requirement. Finally, the RF conditioning and very first beam commissioning on the IH-DTL1 were finished. The beam test results agree well with the simulation results; what's more, the property of the variable output beam energy about the separated functions DTL was verified.展开更多
We propose the construction of a compact linac as the injector of a cancer therapy facility at the Institute of Modern Physics(IMP) of the Chinese Academy of Sciences(CAS). Based on a traditional setup, a new compact ...We propose the construction of a compact linac as the injector of a cancer therapy facility at the Institute of Modern Physics(IMP) of the Chinese Academy of Sciences(CAS). Based on a traditional setup, a new compact fast-bunching design is first introduced to optimize the 600 keV/u RFQ with a 0.05 pm A ^(12)C^(4+) beam. This shortens the RFQ structure length from the standard design value of272–230 cm while effectively regulating the particle loss and emittance growth. In addition, a detailed error analysis was performed after the optimization process. The error sources cover input beam parameters errors, machining errors and alignment errors. The simulation results show that the beam loss and emittance growth of the RFQ are acceptable and within typical ranges of error.展开更多
A new linac injector CSR-LINAC for the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou(HIRFL-CSR) is proposed to improve the performance of the HIRFL. As a key component of the CSRLINAC, the 108.48-M...A new linac injector CSR-LINAC for the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou(HIRFL-CSR) is proposed to improve the performance of the HIRFL. As a key component of the CSRLINAC, the 108.48-MHz radio frequency quadrupole(RFQ) is under design at the Institute of Modern Physics.Heavy ions with mass-to-charge ratios of 3–7 will be accelerated from 4 to 300 keV/u by the RFQ. In the beam dynamics design, the New Four-Section Procedure is adopted to improve the transmission efficiency and obtain a compact structure. In this paper, a transmission efficiency of 98.0% in the 3.07-m-long cavity was obtained. The Interdigital H-type structure is employed because of its mechanical stability and high shunt impedance. The RF performance of the cavity is investigated by the electromagnetic simulation. The optimized results of the electric field to meet the beam dynamics requirements are presented in this paper.展开更多
The scarcity of fresh water resources has become a serious issue hindering the sustainable development of modern civilization.The interfacial solar steam generation(ISSG)system that produces heat on material surface t...The scarcity of fresh water resources has become a serious issue hindering the sustainable development of modern civilization.The interfacial solar steam generation(ISSG)system that produces heat on material surface through photothermal conversion for desalination has been demonstrated as a promising candidate for practical application.Fibrous materials with unique flexibility,durability,processability,practicability,and multifunctionality have attracted considerable attention in the ISSG field.In this review,the basics of fibrous materials,such as their classification,manufacturing methods and flexible fibrous structure,are firstly introduced.Afterward,the outstanding properties of fibrous materials on different dimensions are demonstrated,as well as the versatile morphologies and structures that allow fibrous materials to carry out different roles in ISSG.Moreover,the practicability and multifunctionality of fibrous materials are illustrated in detail by combining specific cases to show their promising potential in practical ISSG application.Finally,existing challenges and future opportunities of fibrous material-based ISSG systems are discussed.展开更多
To date,dynamic sleep environment has been attracted the focus of researchers.Owing to the individual difference on sleep phase and thermal comfort,changes in sleep environment should be occupant-centered,and precise ...To date,dynamic sleep environment has been attracted the focus of researchers.Owing to the individual difference on sleep phase and thermal comfort,changes in sleep environment should be occupant-centered,and precise regulation of the environment required current sleep stages.However,few studies connected occupants and the environment through physiological signal-based model of sleep staging.Therefore,this study tried to develop a data driven sleep staging model with higher accuracy through sleep experiments collecting information.Raw database was processed and selected efficiently according to the characteristics of physiological signals.Finally,the sleep staging model with an average accuracy of 93.9%was built,and other mean indicators(precision:82.5%,recall:83.1%,F1 score:82.8%)performed well.The features adopted by model were found to come from different brain regions,and the global brain signals were suggested to play an important role in the construction of sleep staging model.Moreover,the computational processing of physiology signals should consider their characteristics,i.e.,time domain,frequency domain,time-frequency domain and nonlinear characteristics.The model obtained in this study may deliver a credible reference to advance the research on control of sleep environment.展开更多
Determining required sample size is one of the critical pathways to reproducible,reliable and robust results in human-related studies.This paper aims to answer a fundamental but often overlooked question:what sample s...Determining required sample size is one of the critical pathways to reproducible,reliable and robust results in human-related studies.This paper aims to answer a fundamental but often overlooked question:what sample size is required in surveys of occupant responses to indoor environmental quality(IEQ).The statistical models are introduced in order to promote determining required sample size for various types of data analysis methods commonly used in IEQ field studies.The Monte Carlo simulations are performed to verify the statistical methods and to illustrate the impact of sample size on the study accuracy and reliability.Several examples are presented to illustrate how to determine the value of the parameters in the statistical models based on previous similar research or existing databases.The required sample size including“worst”and“optimal”cases in each condition is obtained by this method and references.It is indicated that 385 is a“worst case”sample size to be adequate for a subgroup analysis,while if the researcher has an estimate of the study design and outcome,the“optimal case”sample size can potentially be reduced.When the required sample size is not achievable,the uncertainty in the result can properly interpret via a confidence interval.It is hoped that this paper would fill in the gap between statistical analysis of sample size and IEQ field research,and it can provide a useful reference for researchers when planning their own studies.展开更多
Mouse cortical radial glial cells(RGCs)are primary neural stem cells that give rise to cortical oligodendrocytes,astrocytes,and olfactory bulb(OB)GABAergic interneurons in late embryogenesis.There are fundamental gaps...Mouse cortical radial glial cells(RGCs)are primary neural stem cells that give rise to cortical oligodendrocytes,astrocytes,and olfactory bulb(OB)GABAergic interneurons in late embryogenesis.There are fundamental gaps in understanding how these diverse cell subtypes are generated.Here,by combining single-cell RNA-Seq with intersectional lineage analyses,we show that beginning at around E16.5,neocortical RGCs start to generate ASCL1^(+)EGFR^(+)apical multipotent intermediate progenitors(MIPCs),which then differentiate into basal MIPCs that express ASCL1,EGFR,OLIG2,and MKI67.These basal MIPCs undergo several rounds of divisions to generate most of the cortical oligodendrocytes and astrocytes and a subpopulation of OB interneurons.Finally,single-cell ATAC-Seq supported our model for the genetic logic underlying the specification and differentiation of cortical glial cells and OB interneurons.Taken together,this work reveals the process of cortical radial glial cell lineage progression and the developmental origins of cortical astrocytes and oligodendrocytes.展开更多
In order to prevent the microwave leakage and mutual interference,more and more microwave absorbing devices are added into the design of electronic products to ensure its routine operation.In this work,we have success...In order to prevent the microwave leakage and mutual interference,more and more microwave absorbing devices are added into the design of electronic products to ensure its routine operation.In this work,we have successfully prepared MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) hierarchical composites by one-pot hydrothermal method and focused on the relationship between structures and electromagnetic absorbing properties.Supported by comprehensive characterizations,M0S_(2) nanosheets were proved to be anchored on the surface and interlayer of Ti_(3)C_(2)T_(x) through a hydrothermal process.Additionally,TiO_(2) nanoparticles were obtained in situ.Due to these hierarchical structures,the MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites showed greatly enhanced microwave absorbing performance.The MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites exhibit a maximum reflection loss value of -33.5 dB at 10.24 GHz and the effective absorption bandwidth covers 3.1GHz(13.9-17 GHz)at the thickness of 1.0 mm,implying the features of wide frequency and light weight.This work in the hierarchical structure of MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites opens a promising door to the exploration of constructing extraordinary electromagnetic wave absorbents.展开更多
Medium spiny neurons(MSNs)in the striatum,which can be divided into D1 and D2 MSNs,originate from the lateral ganglionic eminence(LGE).Previously,we reported that Six3 is a downstream target of Sp8/Sp9 in the transcri...Medium spiny neurons(MSNs)in the striatum,which can be divided into D1 and D2 MSNs,originate from the lateral ganglionic eminence(LGE).Previously,we reported that Six3 is a downstream target of Sp8/Sp9 in the transcriptional regulatory cascade of D2 MSN development and that conditionally knocking out Six3 leads to a severe loss of D2 MSNs.Here,we showed that Six3 mainly functions in D2 MSN precursor cells and gradually loses its function as D2 MSNs mature.Conditional deletion of Six3 had little effect on cell proliferation but blocked the differentiation of D2 MSN precursor cells.In addition,conditional overexpression of Six3 promoted the differentiation of precursor cells in the LGE.We measured an increase of apoptosis in the postnatal striatum of conditional Six3-knockout mice.This suggests that,in the absence of Six3,abnormally differentiated D2 MSNs are eliminated by programmed cell death.These results further identify Six3 as an important regulatory element during D2 MSN differentiation.展开更多
Sleep thermal environment has a great effect on occupants7 sleep quality.The purpose of this study was to explore the relationships between sleep thermal environment parameters and sleep quality in winter and summer.T...Sleep thermal environment has a great effect on occupants7 sleep quality.The purpose of this study was to explore the relationships between sleep thermal environment parameters and sleep quality in winter and summer.The whole experiments involved indoor ambient temperatures(winter:17℃,20℃,23℃;summer:23℃,26℃,29℃)and relative humidity(RH;winter:40%,55%,70%;summer:40%,60%,80%).A total of 18 young subjects(23±2 years old)were divided into the two different season groups to experience the corresponding environmental conditions.Their subjective environmental perception and objective physiological signals were monitored.The results showed that thermal sensations at 20℃in winter,as well as 26℃in summer,were considered as the thermal neutral states.Humid sensation in winter before sleep was susceptible to SET*,while the middle value of SET*(32℃)related to the middle indoor air temperature(26℃)and air humidity(60%)before and after sleep could be the summer combination of neutral thermal environment.Furthermore,cold and wet environment in winter was found to seriously affect the deep sleep.In summer,mild temperature contributing to good sleep quality might weaken the effect of humidity on sleep.Through combining the sleep environmental perception result with contour line and regression analysis on objective sleep quality,the suggested values of thermal environment parameters for young adults(21-25 years old)were as follows:20.3℃and 56%RH in winter,as well as 26.1℃and 52%RH in summer.展开更多
Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac...Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac is operated at the frequency of 53.667 MHz,which is the four times of the SSC operating frequency.In order to improve the longitudinal capture efficiency and increase the beam current extracted from the SSC,an independent multi-harmonics buncher(MHB)operating at a fundamental frequency of 13.417 MHz had been designed and manufactured.Method This buncher adopts the dual-gap structure and sawtooth waveform is generated by multi-harmonics synthetized technology.Beam dynamics simulation with MHB was carried out and discussed in this paper.Furthermore,the beam commissioning using 84Kr14+had been performed on SSC-Linac.Results and conclusion The measured maximum capture efficiency 86.5%was obtained,which was well agreed with the simulation results.Due to the successful commissioning of MHB and the outstanding-performance of SSC-Linac,the extracted beam current from SSC has been improved one order of magnitude higher than before.展开更多
基金supported by the National Natural Science Foundation of China(No.11505256)
文摘The high-intensity heavy-ion accelerator facility(HIAF)is under design at the Institute of Modern Physics(IMP)and will provide an intense ion beam for nuclear physics,atomic mass measurement research,and other applications.As the main ring of HIAF,the BRing accumulates beams to high intensity and accelerates them to high energy.To achieve high intensities up to 1×10^(11)(^(238)U^(34+)),the injection gain of the BRing must be as high as 88.However,multiple multiturn injection supported by the electron cooling system takes a long time,causing substantial beam loss under a strong space charge effect.Hence,a two-plane painting injection scheme is proposed for beam accumulation in the BRing.This scheme uses a tilted injection septum and horizontal and vertical bump magnets to paint the beam into horizontal and vertical phase space simultaneously.In this paper,the two-plane painting injection parameters are optimized,and the resulting injection process is simulated using the Objective Ring Beam Injection and Tracking(ORBIT)code.An injection gain of up to 110.3 with a loss rate of 2:3%is achieved,meeting the requirements of BRing.
基金Medical scientific research project of Sichuan province,China (No.S18014)
文摘Shunt dysfunction is a major complication of transjugular intrahepatic portosystemic shunt(TIPS). Ultrasonography is a preferred method of shunt follow-up after TIPS, but some misjudgments can occur in cases of shunt dysfunction due to peculiarities of the VIATORR stent. Here we report one case and suggest that the first ultrasound evaluation for patients who received TIPS procedure with VIATORR stent should be performed one month after the procedure.
文摘Objective: To determine the efficacy in treatment of vertically unstable sacral fractures with pelvic external fixation and skeletal traction. Patients and Methods: The pelvic external fixation and skeletal traction were applied on 12 cases of vertically unstable sacral fracture (eight males and four females, at age of 19 - 52 years, mean 35.2 years) including two cases of Denis Zone I, nine of Zone II, and one of Zone III. All patients were treated with the pelvic external fixation, and pre- and post-operational longitudinal skeletal traction. Results: The mean operation time, skeletal traction time, skeletal traction removal time and full weight bearing time were 38 min, 4.5 weeks, 8.5 weeks, and 10.3 weeks respectively. All these patients were followed up for 12 - 36 months (average, 22.5 months), which showed no associated complication. The function results were rated as excellent in four cases, good in six and fair in two, with a mean score of 84.4 points, according to Majeed scoring system. Conclusion: The anterior pelvic external fixation with continuous skeletal traction can reliably restore and stabilize the vertically unstable sacrum fracture with excellent functional and radiographic outcomes. It is an ideal method to treat unstably vertical sacral fracture.
基金supported by the National Natural Science Foundation of China(Nos.11375243 and 11405237)the Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06G373)
文摘A 53.667 MHz CW(continuous-wave) heavy ion IH-DTL has been designed for the SSC-LINAC injector of HIRFL-CSR(Heavy Ions Research Facility at Lanzhou-Cooling Storage Ring). It accelerates ions with maximum mass-to-charge ratio of 7.0 from 143 to 295 ke V/u. Low-power RF measurement of the IH-DTL1 has been taken to investigate the RF performance and the quality of the electric field distribution on the beam axis.The measured Q_0 value and the shunt impedance are 10,400 and 198 MX/m, respectively. The electric field distributions on and around the beam axis were evaluated and compared with the design value. By a new approach,the dipole field component is also estimated. The beam dynamics simulation using measured field distribution was presented in this paper. Based on the dynamics analysis in both transverse and longitudinal phase space, the field distribution can meet the design requirement. Finally, the RF conditioning and very first beam commissioning on the IH-DTL1 were finished. The beam test results agree well with the simulation results; what's more, the property of the variable output beam energy about the separated functions DTL was verified.
基金supported by the National Natural Science Foundation of China(No.11375243)the Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06G373)
文摘We propose the construction of a compact linac as the injector of a cancer therapy facility at the Institute of Modern Physics(IMP) of the Chinese Academy of Sciences(CAS). Based on a traditional setup, a new compact fast-bunching design is first introduced to optimize the 600 keV/u RFQ with a 0.05 pm A ^(12)C^(4+) beam. This shortens the RFQ structure length from the standard design value of272–230 cm while effectively regulating the particle loss and emittance growth. In addition, a detailed error analysis was performed after the optimization process. The error sources cover input beam parameters errors, machining errors and alignment errors. The simulation results show that the beam loss and emittance growth of the RFQ are acceptable and within typical ranges of error.
基金supported by the National Natural Science Foundation of China(Nos.11375243,11405237,and 11475235)the Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06G373)
文摘A new linac injector CSR-LINAC for the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou(HIRFL-CSR) is proposed to improve the performance of the HIRFL. As a key component of the CSRLINAC, the 108.48-MHz radio frequency quadrupole(RFQ) is under design at the Institute of Modern Physics.Heavy ions with mass-to-charge ratios of 3–7 will be accelerated from 4 to 300 keV/u by the RFQ. In the beam dynamics design, the New Four-Section Procedure is adopted to improve the transmission efficiency and obtain a compact structure. In this paper, a transmission efficiency of 98.0% in the 3.07-m-long cavity was obtained. The Interdigital H-type structure is employed because of its mechanical stability and high shunt impedance. The RF performance of the cavity is investigated by the electromagnetic simulation. The optimized results of the electric field to meet the beam dynamics requirements are presented in this paper.
基金support from the National Natural Science Foundation of China(52173059,U21A2095)The Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJA540002)The Key Research and Development Program of Hubei Province(2021BAA068).
文摘The scarcity of fresh water resources has become a serious issue hindering the sustainable development of modern civilization.The interfacial solar steam generation(ISSG)system that produces heat on material surface through photothermal conversion for desalination has been demonstrated as a promising candidate for practical application.Fibrous materials with unique flexibility,durability,processability,practicability,and multifunctionality have attracted considerable attention in the ISSG field.In this review,the basics of fibrous materials,such as their classification,manufacturing methods and flexible fibrous structure,are firstly introduced.Afterward,the outstanding properties of fibrous materials on different dimensions are demonstrated,as well as the versatile morphologies and structures that allow fibrous materials to carry out different roles in ISSG.Moreover,the practicability and multifunctionality of fibrous materials are illustrated in detail by combining specific cases to show their promising potential in practical ISSG application.Finally,existing challenges and future opportunities of fibrous material-based ISSG systems are discussed.
基金supported by the National Key R&D Program of China (2022YFC3803201)the National Natural Science Foundation of China (52078291).
文摘To date,dynamic sleep environment has been attracted the focus of researchers.Owing to the individual difference on sleep phase and thermal comfort,changes in sleep environment should be occupant-centered,and precise regulation of the environment required current sleep stages.However,few studies connected occupants and the environment through physiological signal-based model of sleep staging.Therefore,this study tried to develop a data driven sleep staging model with higher accuracy through sleep experiments collecting information.Raw database was processed and selected efficiently according to the characteristics of physiological signals.Finally,the sleep staging model with an average accuracy of 93.9%was built,and other mean indicators(precision:82.5%,recall:83.1%,F1 score:82.8%)performed well.The features adopted by model were found to come from different brain regions,and the global brain signals were suggested to play an important role in the construction of sleep staging model.Moreover,the computational processing of physiology signals should consider their characteristics,i.e.,time domain,frequency domain,time-frequency domain and nonlinear characteristics.The model obtained in this study may deliver a credible reference to advance the research on control of sleep environment.
基金This work is supported by the National Key R&D Program of China(2022YFC3803201)。
文摘Determining required sample size is one of the critical pathways to reproducible,reliable and robust results in human-related studies.This paper aims to answer a fundamental but often overlooked question:what sample size is required in surveys of occupant responses to indoor environmental quality(IEQ).The statistical models are introduced in order to promote determining required sample size for various types of data analysis methods commonly used in IEQ field studies.The Monte Carlo simulations are performed to verify the statistical methods and to illustrate the impact of sample size on the study accuracy and reliability.Several examples are presented to illustrate how to determine the value of the parameters in the statistical models based on previous similar research or existing databases.The required sample size including“worst”and“optimal”cases in each condition is obtained by this method and references.It is indicated that 385 is a“worst case”sample size to be adequate for a subgroup analysis,while if the researcher has an estimate of the study design and outcome,the“optimal case”sample size can potentially be reduced.When the required sample size is not achievable,the uncertainty in the result can properly interpret via a confidence interval.It is hoped that this paper would fill in the gap between statistical analysis of sample size and IEQ field research,and it can provide a useful reference for researchers when planning their own studies.
基金supported by grants from the National Key Research and Development Program of China(2018YFA0108000)the National Natural Science Foundation of China(31630032,31820103006,and 32070971)+1 种基金a Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)ZJLab,and grants from NIH(R01MH094589 and R01NS089777)。
文摘Mouse cortical radial glial cells(RGCs)are primary neural stem cells that give rise to cortical oligodendrocytes,astrocytes,and olfactory bulb(OB)GABAergic interneurons in late embryogenesis.There are fundamental gaps in understanding how these diverse cell subtypes are generated.Here,by combining single-cell RNA-Seq with intersectional lineage analyses,we show that beginning at around E16.5,neocortical RGCs start to generate ASCL1^(+)EGFR^(+)apical multipotent intermediate progenitors(MIPCs),which then differentiate into basal MIPCs that express ASCL1,EGFR,OLIG2,and MKI67.These basal MIPCs undergo several rounds of divisions to generate most of the cortical oligodendrocytes and astrocytes and a subpopulation of OB interneurons.Finally,single-cell ATAC-Seq supported our model for the genetic logic underlying the specification and differentiation of cortical glial cells and OB interneurons.Taken together,this work reveals the process of cortical radial glial cell lineage progression and the developmental origins of cortical astrocytes and oligodendrocytes.
基金financially supported by the National Natural Science Foundation of China(No.U2004177)Outstanding Youth Fund of Henan Province(No.212300410081)Natural Science Research Project of Henan Educational Committee(No.20A43001).
文摘In order to prevent the microwave leakage and mutual interference,more and more microwave absorbing devices are added into the design of electronic products to ensure its routine operation.In this work,we have successfully prepared MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) hierarchical composites by one-pot hydrothermal method and focused on the relationship between structures and electromagnetic absorbing properties.Supported by comprehensive characterizations,M0S_(2) nanosheets were proved to be anchored on the surface and interlayer of Ti_(3)C_(2)T_(x) through a hydrothermal process.Additionally,TiO_(2) nanoparticles were obtained in situ.Due to these hierarchical structures,the MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites showed greatly enhanced microwave absorbing performance.The MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites exhibit a maximum reflection loss value of -33.5 dB at 10.24 GHz and the effective absorption bandwidth covers 3.1GHz(13.9-17 GHz)at the thickness of 1.0 mm,implying the features of wide frequency and light weight.This work in the hierarchical structure of MoS_(2)/TiO_(2)/Ti_(3)C_(2)T_(x) composites opens a promising door to the exploration of constructing extraordinary electromagnetic wave absorbents.
基金the National Key Research and Development Program of China(2018YFAO 108000)the National Natural Science Foundation of China(31630032,81974175,and 31820103006)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX01).
文摘Medium spiny neurons(MSNs)in the striatum,which can be divided into D1 and D2 MSNs,originate from the lateral ganglionic eminence(LGE).Previously,we reported that Six3 is a downstream target of Sp8/Sp9 in the transcriptional regulatory cascade of D2 MSN development and that conditionally knocking out Six3 leads to a severe loss of D2 MSNs.Here,we showed that Six3 mainly functions in D2 MSN precursor cells and gradually loses its function as D2 MSNs mature.Conditional deletion of Six3 had little effect on cell proliferation but blocked the differentiation of D2 MSN precursor cells.In addition,conditional overexpression of Six3 promoted the differentiation of precursor cells in the LGE.We measured an increase of apoptosis in the postnatal striatum of conditional Six3-knockout mice.This suggests that,in the absence of Six3,abnormally differentiated D2 MSNs are eliminated by programmed cell death.These results further identify Six3 as an important regulatory element during D2 MSN differentiation.
基金supported by the National Key R&D Program of China(2018YFC0704503)the National Natural Science Foundation of China(51878405).
文摘Sleep thermal environment has a great effect on occupants7 sleep quality.The purpose of this study was to explore the relationships between sleep thermal environment parameters and sleep quality in winter and summer.The whole experiments involved indoor ambient temperatures(winter:17℃,20℃,23℃;summer:23℃,26℃,29℃)and relative humidity(RH;winter:40%,55%,70%;summer:40%,60%,80%).A total of 18 young subjects(23±2 years old)were divided into the two different season groups to experience the corresponding environmental conditions.Their subjective environmental perception and objective physiological signals were monitored.The results showed that thermal sensations at 20℃in winter,as well as 26℃in summer,were considered as the thermal neutral states.Humid sensation in winter before sleep was susceptible to SET*,while the middle value of SET*(32℃)related to the middle indoor air temperature(26℃)and air humidity(60%)before and after sleep could be the summer combination of neutral thermal environment.Furthermore,cold and wet environment in winter was found to seriously affect the deep sleep.In summer,mild temperature contributing to good sleep quality might weaken the effect of humidity on sleep.Through combining the sleep environmental perception result with contour line and regression analysis on objective sleep quality,the suggested values of thermal environment parameters for young adults(21-25 years old)were as follows:20.3℃and 56%RH in winter,as well as 26.1℃and 52%RH in summer.
基金supported by the National Natural Science Foundation of China(No.11375243)Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06G373).
文摘Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac is operated at the frequency of 53.667 MHz,which is the four times of the SSC operating frequency.In order to improve the longitudinal capture efficiency and increase the beam current extracted from the SSC,an independent multi-harmonics buncher(MHB)operating at a fundamental frequency of 13.417 MHz had been designed and manufactured.Method This buncher adopts the dual-gap structure and sawtooth waveform is generated by multi-harmonics synthetized technology.Beam dynamics simulation with MHB was carried out and discussed in this paper.Furthermore,the beam commissioning using 84Kr14+had been performed on SSC-Linac.Results and conclusion The measured maximum capture efficiency 86.5%was obtained,which was well agreed with the simulation results.Due to the successful commissioning of MHB and the outstanding-performance of SSC-Linac,the extracted beam current from SSC has been improved one order of magnitude higher than before.