Systemic blood circulation is one of life activity’s most important physiological functions.Continuous noninvasive hemodynamicmonitoring is essential for the management of cardiovascular status.However,it is difficul...Systemic blood circulation is one of life activity’s most important physiological functions.Continuous noninvasive hemodynamicmonitoring is essential for the management of cardiovascular status.However,it is difficult to achieve systemichemodynamic monitoring with the daily use of current devices due to the lack of multichannel and time-synchronized operationcapability over the whole body.Here,we utilize a soft microfiber Bragg grating group to monitor spatiotemporalhemodynamics by taking advantage of the high sensitivity,electromagnetic immunity,and great temporal synchronizationbetween multiple remote sensor nodes.A continuous systemic hemodynamic measurement technique is developedusing all-mechanical physiological signals,such as ballistocardiogram signals and pulse waves,to illustrate the actualmechanical process of blood circulation.Multiple hemodynamic parameters,such as systemic pulse transit time,heartrate,blood pressure,and peripheral resistance,are monitored using skin-like microfiber Bragg grating patches conformallyattached at different body locations.Relying on the soft microfiber Bragg grating group,the spatiotemporal hemodynamicmonitoring technique opens up new possibilities in clinical medical diagnosis and daily health management.展开更多
Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with dif...Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with different patterns of liver diseases and high risk populations in different parts of China. Genotypes of HCV in some isolates were further ana- lyzed, based on the data from our laboratory studies and some carefully selected published literatures. Results: The anti-HCV positive rates were 9.7% in patients with acute hepatitis, 13.3% in patients with chronic hepatitis, 18.3% in patients with hepatocel- lular carcinoma, 33.0% in patients with liver cirrho- sis, and 43.2% in patients with posttransfusional hepatitis (average, 16.2% in patients with liver di- seases). The anti-HCV positive rates in the high risk populations were 36.4% in leukemic patients, 43.0% in hemodialysis patients, 12.7% in blood do- nors, 64.1% in drug abusers, 13.1% in prostitutes, and 2.57% in naturally healthy people. At least 4 clades (clades 1, 2, 3 and 6) of HCV were found in China with different geographic and demographic distributions. Genotype 1b was the most widely dis- tributed genotype, and genotype 3 was mainly found in Yunnan Province, Southwest China. Conclusion: China has a high incidence of HCV in- fection. Our results will provide a strategic basis for diagnosis, treatment and possibly prophylaxis of he- patitis C virus diseases.展开更多
To further improve the performance of UKF(Unscented Kalman Filter) algorithm used in BDS/SINS(BeiDou Navigation Satellite System/Strap down Inertial Navigation System), an improved GM-UKF(Gaussian Mixture Unscented Ka...To further improve the performance of UKF(Unscented Kalman Filter) algorithm used in BDS/SINS(BeiDou Navigation Satellite System/Strap down Inertial Navigation System), an improved GM-UKF(Gaussian Mixture Unscented Kalman Filter) considering non-Gaussian distribution is discussed in this paper. This new algorithm using SVD(Singular Value Decomposition) is proposed to alternative covariance square root calculation in UKF sigma point production. And to end the rapidly increasing number of Gaussian distributions, PDF(Probability Density Function) re-approximation is conducted. In principle this efficiency algorithm proposed here can achieve higher computational speed compared with traditional GM-UKF. And simulation experiment result show that, compared with UKF and GM-UKF algorithm, new algorithm implemented in BDS/SINS tightly integrated navigation system is suitable for handling nonlinear/non-Gaussian integrated navigation position calculation, for its lower computational complexity with high accuracy.展开更多
Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) report...Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.展开更多
We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of...We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo source.The electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport measurements.Furthermore,the direct van der Pauw transport also confirms its relatively high carrier mobility.Our study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement results.Such methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.展开更多
Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution. The XRD ...Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution. The XRD pattern and TEM confirm that the uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of Ti-TMS1 prepared with dodecylphosphate and hexadecylphosphate as templates. Furthermore, after the templates were removed, the mesostructure of Ti-TMS1 was preserved to a great degree than that of Ti-TMS2.展开更多
In marginally twisted bilayer graphene,the Moirépattern consists of the maximized AB(BA)stacking regions,minimized AA stacking regions and triangular networks of domain walls.Here we realize the strain-modulated ...In marginally twisted bilayer graphene,the Moirépattern consists of the maximized AB(BA)stacking regions,minimized AA stacking regions and triangular networks of domain walls.Here we realize the strain-modulated electronic structures of marginally twisted bilayer graphene by scanning tunneling microscopy/spectroscopy and density functional theory(DFT)calculations.The experimental data show four peaks near the Fermi energy at the AA regions.DFT calculations indicate that the two new peaks closer to the Fermi level may originate from the intrinsic heterostrain and the electric field implemented by back gate is likely to account for the observed shift of the four peaks.Furthermore,the d I/d V map across Moirépatterns with different strain strengths exhibits a distinct appearance of the helical edge states.展开更多
A simple and direct method for preparation of N-substituted spirocyclic dieSter of □-amino phosphonic acid (4) in high yield is introduced. The reaction consists of the threecomponent reachon of phenylurea (1), an ar...A simple and direct method for preparation of N-substituted spirocyclic dieSter of □-amino phosphonic acid (4) in high yield is introduced. The reaction consists of the threecomponent reachon of phenylurea (1), an aromatic aldehyde (2), and 3,9-dichloro-2,4,8,10-tetraoxa- 3, 9 -diphosphaspiro [5,5] undecane (3) in anhydrous benzene.展开更多
Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes...Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.展开更多
Morning commute problem has always been concerned by researchers in transportation research field.For the bottleneck existing in the road network between home and school,this paper studies the household travel with di...Morning commute problem has always been concerned by researchers in transportation research field.For the bottleneck existing in the road network between home and school,this paper studies the household travel with different kinds of activities,i.e.,home-school-home trip and home-school-workplace trip.Individuals just send their children to school and then go home,which is named school travel.Individuals need to send their children to school firstly and then go to work,which is named household travel.Firstly,according to the proportions of two types of travelers and school-work start time difference,the possible equilibrium cases are solved and the conditions for the occurrence of each case are revealed.Different from the traditional bottleneck model with a unique equilibrium traffic pattern,the mixed travel case has six possible equilibrium traffic patterns.Secondly,the cost of traveler is analyzed for all possible equilibrium traffic patterns.Result shows that equilibrium trip costs of two types of travelers are more sensitive to the number of travelers in that class than the number in another class in all possible equilibrium cases.Finally,the influence of school-work start time difference on the total travel cost is discussed.Result shows that the total system travel cost can be reduced by appropriately adjusting the difference of school-work start time.展开更多
National Center for Nanoscience and Technology(NCNST),China,established in December 2003,is co-founded by the Chinese Academy of Sciences(CAS)and the Ministry of Education as an institution dedicated to fundamental an...National Center for Nanoscience and Technology(NCNST),China,established in December 2003,is co-founded by the Chinese Academy of Sciences(CAS)and the Ministry of Education as an institution dedicated to fundamental and applied researches in the field of nanoscience and technology,especially those with important potential applications.NCNST is operated under the supervision of the Governing Board and aims to become a world-class research center,as well as public technological platform and young talents training center in the field,and to act as an important bridge for international academic exchange and collaboration.The NCNST currently has three CAS Key Laboratories:the CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety,the CAS Key Laboratory for Standardization and Measurement for Nanotechnology and the CAS Key Laboratory for Nanosystem and Hierarchical Fabrication.In 2020,the CAS Key Laboratory of Nanophotonic Materials and Devices started construction.Besides,there are Division of Nanotechnology Development,Nanofabrication Laboratory,Intelligent Nanosensing Laboratory and Theoretical Laboratory.展开更多
We aimed to assess the associations of large artery stenosis(LAS)and cerebral small vessel disease(CSVD)with the risk of ischemic stroke and to investigate their respective and combined contributions.In the prospectiv...We aimed to assess the associations of large artery stenosis(LAS)and cerebral small vessel disease(CSVD)with the risk of ischemic stroke and to investigate their respective and combined contributions.In the prospective population-based Shunyi Study,1,082 stroke-free participants aged 55.9±9.1 years were included.Participants were followed for incident stroke throughout the study period(2013-2019).Total small vessel disease score was used to measure CSVD burden.Cervico-cerebral large artery stenosis was evaluated via brain magnetic resonance angiography and carotid ultrasound.We estimated the risk of ischemic stroke in relation to LAS and CSVD with Cox regression models.During a mean follow-up of 4.2 years,34 participants(3.1%)experienced at least one ischemic stroke.Severe LAS(≥50% stenosis versus no stenosis:HR=3.27(95%CI:1.31-8.18))and high CSVD burden(total small vessel disease score 2-4 versus 0 point:HR=12.73(4.83-33.53))were associated with increased stroke risk independently.In multivariate models,CSVD burden(7.72%)explained a larger portion of the variation in stroke risk than severity of LAS(3.49%).Our findings identified that both LAS and CSVD were associated with future ischemic stroke in asymptomatic subjects,while those with high CSVD burden deserve more attention in primary prevention of stroke.展开更多
Identification of a suitable nonhuman primate(NHP)model of COVID-19 remains challenging.Here,we characterized severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in three NHP species:Old World monkeys...Identification of a suitable nonhuman primate(NHP)model of COVID-19 remains challenging.Here,we characterized severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in three NHP species:Old World monkeys Macaca mulatta(M.mulatta)and Macaca fascicularis(M.fascicularis)and New World monkey Callithrix jacchus(C.jacchus).Infected M.mulatta and M.fascicularis showed abnormal chest radiographs,an increased body temperature and a decreased body weight.Viral genomes were detected in swab and blood samples from all animals.Viral load was detected in the pulmonary tissues of M.mulatta and M.fascicularis but not C.jacchus.Furthermore,among the three animal species,M.mulatta showed the strongest response to SARS-CoV-2,including increased inflammatory cytokine expression and pathological changes in the pulmonary tissues.Collectively,these data revealed the different susceptibilities of Old World and New World monkeys to SARS-CoV-2 and identified M.mulatta as the most suitable for modeling COVID-19.展开更多
Monitoring the chemical and structural changes in protein side chains and endpoints by infrared(IR)spectroscopy is important for studying the chemical reaction and physical adsorption process of proteins.However,the d...Monitoring the chemical and structural changes in protein side chains and endpoints by infrared(IR)spectroscopy is important for studying the chemical reaction and physical adsorption process of proteins.However,the detection of side chains and endpoints in nanoscale proteins is still challenging due to its weak IR response.Here,by designing a double layered graphene plasmon sensor on MgF2/Si substrate in the IR fingerprint region,we detect the vibrational modes in side chains and endpoints(1397 cm^-1 and 1458 cm^-1)of monolayer protein.The sensor could be applied on biochemistry to investigate the physical and chemical reaction of biomolecules.展开更多
Saliva has recently attracted increasing interest for disease diagnosis since it presents a rich pool of biological markers such as proteins,DNA,RNA,hormones,microorganisms.Notably,saliva collection is convenient and ...Saliva has recently attracted increasing interest for disease diagnosis since it presents a rich pool of biological markers such as proteins,DNA,RNA,hormones,microorganisms.Notably,saliva collection is convenient and safe,making it a perfect candidate for point-of-care testing(POCT)techniques.Several saliva-based POCT devices have been developed for large-scale pandemic screening,self-diagnosis,daily health monitoring.展开更多
基金supported by the National Key R&D Program of China(2021YFA1401103)the National Natural Science Foundation of China(61925502 and 51772145).
文摘Systemic blood circulation is one of life activity’s most important physiological functions.Continuous noninvasive hemodynamicmonitoring is essential for the management of cardiovascular status.However,it is difficult to achieve systemichemodynamic monitoring with the daily use of current devices due to the lack of multichannel and time-synchronized operationcapability over the whole body.Here,we utilize a soft microfiber Bragg grating group to monitor spatiotemporalhemodynamics by taking advantage of the high sensitivity,electromagnetic immunity,and great temporal synchronizationbetween multiple remote sensor nodes.A continuous systemic hemodynamic measurement technique is developedusing all-mechanical physiological signals,such as ballistocardiogram signals and pulse waves,to illustrate the actualmechanical process of blood circulation.Multiple hemodynamic parameters,such as systemic pulse transit time,heartrate,blood pressure,and peripheral resistance,are monitored using skin-like microfiber Bragg grating patches conformallyattached at different body locations.Relying on the soft microfiber Bragg grating group,the spatiotemporal hemodynamicmonitoring technique opens up new possibilities in clinical medical diagnosis and daily health management.
文摘Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with different patterns of liver diseases and high risk populations in different parts of China. Genotypes of HCV in some isolates were further ana- lyzed, based on the data from our laboratory studies and some carefully selected published literatures. Results: The anti-HCV positive rates were 9.7% in patients with acute hepatitis, 13.3% in patients with chronic hepatitis, 18.3% in patients with hepatocel- lular carcinoma, 33.0% in patients with liver cirrho- sis, and 43.2% in patients with posttransfusional hepatitis (average, 16.2% in patients with liver di- seases). The anti-HCV positive rates in the high risk populations were 36.4% in leukemic patients, 43.0% in hemodialysis patients, 12.7% in blood do- nors, 64.1% in drug abusers, 13.1% in prostitutes, and 2.57% in naturally healthy people. At least 4 clades (clades 1, 2, 3 and 6) of HCV were found in China with different geographic and demographic distributions. Genotype 1b was the most widely dis- tributed genotype, and genotype 3 was mainly found in Yunnan Province, Southwest China. Conclusion: China has a high incidence of HCV in- fection. Our results will provide a strategic basis for diagnosis, treatment and possibly prophylaxis of he- patitis C virus diseases.
基金supported by Chinese National Natural ScienceFoundation (41674016 and 41274016)
文摘To further improve the performance of UKF(Unscented Kalman Filter) algorithm used in BDS/SINS(BeiDou Navigation Satellite System/Strap down Inertial Navigation System), an improved GM-UKF(Gaussian Mixture Unscented Kalman Filter) considering non-Gaussian distribution is discussed in this paper. This new algorithm using SVD(Singular Value Decomposition) is proposed to alternative covariance square root calculation in UKF sigma point production. And to end the rapidly increasing number of Gaussian distributions, PDF(Probability Density Function) re-approximation is conducted. In principle this efficiency algorithm proposed here can achieve higher computational speed compared with traditional GM-UKF. And simulation experiment result show that, compared with UKF and GM-UKF algorithm, new algorithm implemented in BDS/SINS tightly integrated navigation system is suitable for handling nonlinear/non-Gaussian integrated navigation position calculation, for its lower computational complexity with high accuracy.
基金This study was supported by research grants from ICGEB Collaborative Research Program (CRP/CHN96-05) and from China Yunnan Provincial Science & Technology Commission International Collaborative Research Program (97C009).
文摘Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.
基金Project supported by the National Natural Science Foundation of China(Grant No.61888102)the National Natural Science Foundation of China(Grant No.12004417)+5 种基金the National Key Research and Development Program of China(Grant Nos.2018YFA0305800 and 2019YFA0308500)the National Natural Science Foundation of China(Grant No.U2032206)Chinese Academy of Sciences(Grant Nos.XDB36000000,YSBR-003,and 112111KYSB20160061)Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(Grant Nos.XDB30000000 and XDB28000000)Youth Innovation Promotion Association of CAS(Grant No.Y201902)CAS Project for Young Scientists in Basic Research(Grant No.YSBR-003)。
文摘We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo source.The electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport measurements.Furthermore,the direct van der Pauw transport also confirms its relatively high carrier mobility.Our study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement results.Such methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.
文摘Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution. The XRD pattern and TEM confirm that the uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of Ti-TMS1 prepared with dodecylphosphate and hexadecylphosphate as templates. Furthermore, after the templates were removed, the mesostructure of Ti-TMS1 was preserved to a great degree than that of Ti-TMS2.
基金supported by the National Natural Science Foundation of China(Grant Nos.61888102 and U2032206)the National Key Research and Development Program of China(Grant Nos.2018YFA0305800 and 2019YFA0308500)+1 种基金Chinese Academy of Sciences(Grant Nos.XDB30000000,XDB36000000,YSBR003,and 112111KYSB20160061)the Fundamental Research Funds for the Central Universities,China。
文摘In marginally twisted bilayer graphene,the Moirépattern consists of the maximized AB(BA)stacking regions,minimized AA stacking regions and triangular networks of domain walls.Here we realize the strain-modulated electronic structures of marginally twisted bilayer graphene by scanning tunneling microscopy/spectroscopy and density functional theory(DFT)calculations.The experimental data show four peaks near the Fermi energy at the AA regions.DFT calculations indicate that the two new peaks closer to the Fermi level may originate from the intrinsic heterostrain and the electric field implemented by back gate is likely to account for the observed shift of the four peaks.Furthermore,the d I/d V map across Moirépatterns with different strain strengths exhibits a distinct appearance of the helical edge states.
文摘A simple and direct method for preparation of N-substituted spirocyclic dieSter of □-amino phosphonic acid (4) in high yield is introduced. The reaction consists of the threecomponent reachon of phenylurea (1), an aromatic aldehyde (2), and 3,9-dichloro-2,4,8,10-tetraoxa- 3, 9 -diphosphaspiro [5,5] undecane (3) in anhydrous benzene.
基金the financial support of the National Natural Science Foundation of China(Nos.22075276,U19A2016,U22B6012)CAS Strategic Leading Science&Technology Program(A)(No.XDA21070000)+2 种基金Dalian High Level Talent Innovation Support Program(No.2020RD05)the Development of Scientic and Technological Project of the Jilin Province(No.20210101126JC)International Partnership Program of Chinese Academy of Sciences(No.121421KYSB20210028)。
文摘Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.
文摘Morning commute problem has always been concerned by researchers in transportation research field.For the bottleneck existing in the road network between home and school,this paper studies the household travel with different kinds of activities,i.e.,home-school-home trip and home-school-workplace trip.Individuals just send their children to school and then go home,which is named school travel.Individuals need to send their children to school firstly and then go to work,which is named household travel.Firstly,according to the proportions of two types of travelers and school-work start time difference,the possible equilibrium cases are solved and the conditions for the occurrence of each case are revealed.Different from the traditional bottleneck model with a unique equilibrium traffic pattern,the mixed travel case has six possible equilibrium traffic patterns.Secondly,the cost of traveler is analyzed for all possible equilibrium traffic patterns.Result shows that equilibrium trip costs of two types of travelers are more sensitive to the number of travelers in that class than the number in another class in all possible equilibrium cases.Finally,the influence of school-work start time difference on the total travel cost is discussed.Result shows that the total system travel cost can be reduced by appropriately adjusting the difference of school-work start time.
文摘National Center for Nanoscience and Technology(NCNST),China,established in December 2003,is co-founded by the Chinese Academy of Sciences(CAS)and the Ministry of Education as an institution dedicated to fundamental and applied researches in the field of nanoscience and technology,especially those with important potential applications.NCNST is operated under the supervision of the Governing Board and aims to become a world-class research center,as well as public technological platform and young talents training center in the field,and to act as an important bridge for international academic exchange and collaboration.The NCNST currently has three CAS Key Laboratories:the CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety,the CAS Key Laboratory for Standardization and Measurement for Nanotechnology and the CAS Key Laboratory for Nanosystem and Hierarchical Fabrication.In 2020,the CAS Key Laboratory of Nanophotonic Materials and Devices started construction.Besides,there are Division of Nanotechnology Development,Nanofabrication Laboratory,Intelligent Nanosensing Laboratory and Theoretical Laboratory.
基金supported by the National Key Research and Development Program of China(2016YFB1001402)National Natural Science Foundation of China(81971138)+2 种基金Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS)(2017-I2M-3-008)Strategic Priority Research Program(Pilot study)“Biological basis of aging and therapeutic strategies”of the Chinese Academy of Sciences(XDPB10)Research Foundation for Young Scholars of Peking Union Medical College Hospital(PUMCH201911275)。
文摘We aimed to assess the associations of large artery stenosis(LAS)and cerebral small vessel disease(CSVD)with the risk of ischemic stroke and to investigate their respective and combined contributions.In the prospective population-based Shunyi Study,1,082 stroke-free participants aged 55.9±9.1 years were included.Participants were followed for incident stroke throughout the study period(2013-2019).Total small vessel disease score was used to measure CSVD burden.Cervico-cerebral large artery stenosis was evaluated via brain magnetic resonance angiography and carotid ultrasound.We estimated the risk of ischemic stroke in relation to LAS and CSVD with Cox regression models.During a mean follow-up of 4.2 years,34 participants(3.1%)experienced at least one ischemic stroke.Severe LAS(≥50% stenosis versus no stenosis:HR=3.27(95%CI:1.31-8.18))and high CSVD burden(total small vessel disease score 2-4 versus 0 point:HR=12.73(4.83-33.53))were associated with increased stroke risk independently.In multivariate models,CSVD burden(7.72%)explained a larger portion of the variation in stroke risk than severity of LAS(3.49%).Our findings identified that both LAS and CSVD were associated with future ischemic stroke in asymptomatic subjects,while those with high CSVD burden deserve more attention in primary prevention of stroke.
基金supported by the National Research and Development Project of China(2020YFC0841100,2020YFC0846400,and 2020YFA0707600)CAMS Innovation Fund for Medical Sciences(2016-I2M-2-006 and 2020-I2M-CoV19-012)+1 种基金the Talents Project of Yunnan Province(2017HB068)the Special Funds for High-level Health and Family Planning Technical Personnel training of Yunnan Province(D-201653).
文摘Identification of a suitable nonhuman primate(NHP)model of COVID-19 remains challenging.Here,we characterized severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in three NHP species:Old World monkeys Macaca mulatta(M.mulatta)and Macaca fascicularis(M.fascicularis)and New World monkey Callithrix jacchus(C.jacchus).Infected M.mulatta and M.fascicularis showed abnormal chest radiographs,an increased body temperature and a decreased body weight.Viral genomes were detected in swab and blood samples from all animals.Viral load was detected in the pulmonary tissues of M.mulatta and M.fascicularis but not C.jacchus.Furthermore,among the three animal species,M.mulatta showed the strongest response to SARS-CoV-2,including increased inflammatory cytokine expression and pathological changes in the pulmonary tissues.Collectively,these data revealed the different susceptibilities of Old World and New World monkeys to SARS-CoV-2 and identified M.mulatta as the most suitable for modeling COVID-19.
基金supported by the National Basic Key Research Program of China(No.2015CB932400)the National Key Research and Development Program of China(No.2016YFA0201600)+4 种基金the National Natural Science Foundation of China(Nos.11504063,11674073,11704085,and 11427808)the Bureau of International Cooperationthe Key Program of the Bureau of Frontier Sciences and Education,Chinese Academy of Sciences(No.QYZDB-SSW-SLH021)the Key Project of Chinese Academy of Sciences(No.ZDBS-SSW-JSC002)the Youth Innovation Promotion Association CAS
文摘Monitoring the chemical and structural changes in protein side chains and endpoints by infrared(IR)spectroscopy is important for studying the chemical reaction and physical adsorption process of proteins.However,the detection of side chains and endpoints in nanoscale proteins is still challenging due to its weak IR response.Here,by designing a double layered graphene plasmon sensor on MgF2/Si substrate in the IR fingerprint region,we detect the vibrational modes in side chains and endpoints(1397 cm^-1 and 1458 cm^-1)of monolayer protein.The sensor could be applied on biochemistry to investigate the physical and chemical reaction of biomolecules.
基金supported by the Natural Science Foundation of China(51925203,U2032206)Innovation cross team project of Chinese Academy of Sciences(JCTD-2018-03)Science and Technology Service Network Project(STS Program)of the Chinese Academy of Sciences(KFJ-STS-ZDTP-063)。
文摘Saliva has recently attracted increasing interest for disease diagnosis since it presents a rich pool of biological markers such as proteins,DNA,RNA,hormones,microorganisms.Notably,saliva collection is convenient and safe,making it a perfect candidate for point-of-care testing(POCT)techniques.Several saliva-based POCT devices have been developed for large-scale pandemic screening,self-diagnosis,daily health monitoring.