Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydro...Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods.展开更多
As the major cell precursors in osteogenesis, mesenchymal stem cells(MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversia...As the major cell precursors in osteogenesis, mesenchymal stem cells(MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversial. Composed of multiple constituent enhancers, super enhancers(SEs) are powerful cis-regulatory elements that identify genes that ensure sequential differentiation. The present study demonstrated that SEs were indispensable for MSC osteogenesis and involved in osteoporosis development. Through integrated analysis, we identified the most common SE-targeted and osteoporosis-related osteogenic gene,ZBTB16. ZBTB16, positively regulated by SEs, promoted MSC osteogenesis but was expressed at lower levels in osteoporosis.Mechanistically, SEs recruited bromodomain containing 4(BRD4) at the site of ZBTB16, which then bound to RNA polymerase IIassociated protein 2(RPAP2) that transported RNA polymerase Ⅱ(POL Ⅱ) into the nucleus. The subsequent synergistic regulation of POL Ⅱ carboxyterminal domain(CTD) phosphorylation by BRD4 and RPAP2 initiated ZBTB16 transcriptional elongation, which facilitated MSC osteogenesis via the key osteogenic transcription factor SP7. Bone-targeting ZBTB16 overexpression had a therapeutic effect on the decreased bone density and remodeling capacity of Brd4^(fl/fl)Prx1-cre mice and osteoporosis(OP) models.Therefore, our study shows that SEs orchestrate the osteogenesis of MSCs by targeting ZBTB16 expression, which provides an attractive focus and therapeutic target for osteoporosis.展开更多
The South Atlantic Anomaly(SAA)is a region where the geomagnetic field is significantly lower than that of the surrounding area.On the basis of the models of CHAOS-7.8,Mass Spectrometer Incoherent Scatter Model(NRLMSI...The South Atlantic Anomaly(SAA)is a region where the geomagnetic field is significantly lower than that of the surrounding area.On the basis of the models of CHAOS-7.8,Mass Spectrometer Incoherent Scatter Model(NRLMSISE-00),and International Reference Ionosphere 2016(IRI-2016),we theoretically investigated the lower and upper boundaries of the ionospheric dynamo region inside the SAA.In the ionospheric dynamo region,electrons are coupled with magnetic field lines,whereas ions are decoupled from magnetic field lines.Our results showed that the ionospheric dynamo region inside the SAA is higher and larger than that outside the SAA.We also studied the boundary variations of the dynamo region inside the SAA depending on the seasons and solar activities.We found that the dynamo region inside the SAA is the highest and largest in the summer of the southern hemisphere at solar maximum.The larger and higher altitude range of the ionospheric dynamo region in the SAA can contribute to the stronger ionospheric currents in this region.展开更多
Since the first laser was invented,the pursuit of high-energy lasers(HELs)has always been enthusiastic.The first revolution of HELs was pushed by the fusion of laser and aerospace in the 1960s,with the chemical rocket...Since the first laser was invented,the pursuit of high-energy lasers(HELs)has always been enthusiastic.The first revolution of HELs was pushed by the fusion of laser and aerospace in the 1960s,with the chemical rocket engines giving fresh impetus to the birth of gas flow and chemical lasers,which finally turned megawatt lasers from dream into reality.Nowadays,the development of HELs has entered the age of electricity as well as the rocket engines.The properties of current electric rocket engines are highly consistent with HELs’goals,including electrical driving,effective heat dissipation,little medium consumption and extremely light weight and size,which inspired a second fusion of laser and aerospace and motivated the exploration for potential HELs.As an exploratory attempt,a new configuration of diode pumped metastable rare gas laser was demonstrated,with the gain generator resembling an electric rocket-engine for improved power scaling ability.展开更多
Objective: In this study, we aimed to estimate the updated incidence and mortality of primary bone cancers based on population-based cancer registration data in 2014, collected by the National Central Cancer Registry ...Objective: In this study, we aimed to estimate the updated incidence and mortality of primary bone cancers based on population-based cancer registration data in 2014, collected by the National Central Cancer Registry of China(NCCRC).Methods: In 2017, 339 registries' data were qualified based on data quality criteria set down by the NCCRC.Cases of primary bone cancers were retrieved from the national database. We estimated numbers of primary bone cancer cases and deaths in China using age-specific rates and corresponding national population stratified by area,sex, age-group(0, 1-4, 5-9, 10-14, …, 85+). Chinese standard population in 2000 and Segi's World population were applied for the calculation of age-standardized incidence and mortality rates.Results: In 2014, 24,000 primary bone cancer cases and 17,200 deaths attributable to primary bone cancers were estimated to have occurred in China. The crude incidence rate of primary bone cancers was 1.76/100,000, with agestandardized incidence rate by Chinese standard population(ASIRC) and by World standard population(ASIRW)being 1.35/100,000 and 1.32/100,000, respectively. The crude mortality rate of primary bone cancers was1.26/100,000, with age-standardized mortality rate by Chinese standard population(ASMRC) and by World standard population(ASMRW) being 0.88/100,000 and 0.86/100,000, respectively. Age-specific incidence curve was bimodally distributed with age, with the first peak occurring in the second decade of the life and the second peak in the elderly. Males had higher crude and age-standardized rates for both incidence and mortality compared with females. Both crude and age-standardized incidence rates were higher in rural areas than in urban areas, so were the crude and age-standardized mortality rates.Conclusions: This population-based study presents the most recently available estimates on primary bone cancers in China, revealing that the males are 1.34 times as much as females suffering from primary bone cancers and the adolescents in puberty and the elderly are predominantly affected groups by these cancers. High-quality cancer registration data are a prerequisite for undertaking further study for gaining insight into the causes and risk factors for primary bone cancers in China.展开更多
Bamboo forest is an important forest type in subtropical China and is characterized by fast growth and high carbon sequestration capacity. However, the dynamics of carbon fluxes during the fast growing period of bambo...Bamboo forest is an important forest type in subtropical China and is characterized by fast growth and high carbon sequestration capacity. However, the dynamics of carbon fluxes during the fast growing period of bamboo shoots and their correlation with environment factors are poorly understood. We measured carbon dioxide exchange and climate variables using open-path eddy covariance methods during the 2011 growing season in a Moso bamboo forest(MB, Phyllostchys edulis) and a Lei bamboo forest(LB, Phyllostachys violascens) in Zhejiang province,China. The bamboo forests were carbon sinks during the growing season. The minimum diurnal net ecosystem exchange(NEE) at MB and LB sites were-0.64 and-0.66 mg C m^(-2) s^(-1), respectively. The minimum monthly NEE, ecosystem respiration(RE), and gross ecosystem exchange(GEE) were-99.3 ± 4.03, 76.2 ±2.46, and^(-1)91.5 ± 4.98 g C m^(-2) month^(-1), respectively,at MB site, compared with-31.8 ± 3.44, 70.4 ± 1.41,and^(-1)57.9 ± 4.86 g C m^(-2) month^(-1), respectively, at LB site. Maximum RE was 92.1 ± 1.32 g C m^(-2) month^(-1) at MB site and 151.0 ± 2.38 g C m^(-2) month^(-1) at LB site.Key control factors varied by month during the growing season, but across the whole growing season, NEE and GEE at both sites showed similar trends in sensitivities to photosynthetic active radiation and vapor pressure deficit,and air temperature had the strongest correlation with RE at both sites. Carbon fluxes at LB site were more sensitive to soil water content compared to those at MB site. Both onyear(years when many new shoots are produced) and offyear(years when none or few new shoots are produced)should be studied in bamboo forests to better understand their role in global carbon cycling.展开更多
The quality and safety crisis of agricultural products on the one hand is the crisis of harm of agricultural products,and on the other hand is the crisis of information dissemination. This paper analyzed the character...The quality and safety crisis of agricultural products on the one hand is the crisis of harm of agricultural products,and on the other hand is the crisis of information dissemination. This paper analyzed the characteristics of content of the quality and safety crisis information of tropical agricultural products. On the basis of these characteristics,it came up with strategies and recommendations for solving the problems of quality and safety of tropical agricultural products,including establishing the emergency response system for quality and safety crisis of tropical agricultural products,bringing into play the social responsibilities of scientific research institutions,and bringing into play authoritative effect of scientific experts.展开更多
The major impacts of climate change play a substantial role in triggering human migration, especially in the coastal areas. The individual or combined effects of climate change are likely to trigger mass human movemen...The major impacts of climate change play a substantial role in triggering human migration, especially in the coastal areas. The individual or combined effects of climate change are likely to trigger mass human movement both within and across international borders. People rarely move for a single reason;the motivation to migrate is complex of many factors. The main goal of this article is to identify the factors related to the decision to migrate taken by refugees in the coastal area. To assess this objective we employ exploratory factor analysis and structural equation modeling (SEM) and find that different factors influence refugees’ migration decision differently. From the findings, it is seen that loss of shelter, extreme events, decreasing soil fertility and food shortage, variability in temperature patterns and exhaustion of natural resources are the most important environmental factors that affect the decision to migrate of climate refugees. Low income, increasing price, decreasing purchasing power are the most important economic factors that influence migration decision. No social factors have significant effect on migration decision while safety as a political factor has a moderate influence on refugees’ decision to migrate. Finally, this article provides some recommendations for recognition of and protection for migrants forced to move to safer places due to certain direct impacts of climate change, notwithstanding the existence of multi-causality.展开更多
We perform a statistical analysis of data from the Mars Atmosphere and Volatile Evolution (MAVEN) project on the global distribution of protons in the Martian magnetosheath. Our results show that the proton number den...We perform a statistical analysis of data from the Mars Atmosphere and Volatile Evolution (MAVEN) project on the global distribution of protons in the Martian magnetosheath. Our results show that the proton number density distribution has a south-north asymmetry. This south-north asymmetry is most likely caused by the south-north asymmetric distributions of the crustal magnetic fields at Mars. The strong crustal magnetic fields push the inner boundary of magnetosheath to a higher altitude in the southern hemisphere. Due to the outward movement of the inner boundary of the magnetosheath, a compressed magnetosheath forms, causing subsequent increases in proton number density, thermal pressure, and total pressure. Eventually, a balance is reached between the increased total pressure inside the magnetosheath and the increased magnetic pressure inside the induced magnetosphere. Our statistical study suggests that the Martian crustal magnetic fields can strongly affect the proton number density distribution in the Martian magnetosheath.展开更多
The Martian hydrogen exosphere extends out of the bow shock, forming a "hydrogen corona". The solar wind interacts directly with the hydrogen corona. During an ICME event on 7 March 2015, the SWIA instrument...The Martian hydrogen exosphere extends out of the bow shock, forming a "hydrogen corona". The solar wind interacts directly with the hydrogen corona. During an ICME event on 7 March 2015, the SWIA instrument onboard Mars Atmosphere and Volatile Evolution mission (MAVEN) observed that the pick-up H+ fluxes in upstream solar wind were enhanced. Also increased were the penetrating H+ fluxes in the Martian atmosphere. Quantitatively, these penetrating H+ fluxes cannot increase by a factor of 5 simply due to a factor of 3 increase in the solar wind density, suggesting that the increased abundance of exospheric hydrogen upstream of the bow shock was a consequence of the passage of the ICME. A denser outer hydrogen corona at high altitudes suggests that the expansion of the neutral atmosphere was caused by the ICME. The excited and heated hydrogen exosphere probably indicates an elevated hydrogen escape rate during an ICME.展开更多
Based on the vehicle front crash finite element analysis, it shows that there is a large acceleration, so it needs further optimization. In order to improve the performance of vehicle collision, eight parts were selec...Based on the vehicle front crash finite element analysis, it shows that there is a large acceleration, so it needs further optimization. In order to improve the performance of vehicle collision, eight parts were selected which have large impact for the result, its thickness as design variables to the right of the B-pillar acceleration peak of optimization goal;17 sample points were selected by Latin hypercube sampling method. Many structure parameters are optimized using sequential quadratic program (SQP) based on the surrogate model. The results show that the improved RSM has high accuracy;the right B-pillar acceleration reduced approximately 22.8%, reached the expected objective and was more conducive to the occupant safety.展开更多
Deep eutectic solvents(DESs)have been considered as novel and economic alternatives to traditional lubricants because of their similar physicochemical performance.In this study,choline chloride(ChCl)DESs were successf...Deep eutectic solvents(DESs)have been considered as novel and economic alternatives to traditional lubricants because of their similar physicochemical performance.In this study,choline chloride(ChCl)DESs were successfully synthesized via hydrogen-bonding networks of urea and thiourea as the hydrogen bond donors(HBDs).The as-synthesized ChCl-urea and ChCl-thiourea DESs had excellent thermal stability and displayed good lubrication between steel/steel tribo-pairs.The friction coefficient and wear rate of ChCl-thiourea DES were 50.1%and 80.6%,respectively,lower than those of ChCl-urea DES for GCr15/45 steel tribo-pairs.However,for GCr15/Q45 steel,ChCl-urea DES decreased the wear rate by 85.0%in comparison to ChCl-thiourea DES.Under ChCl-thiourea DES lubrication,the tribo-chemical reaction film composed of FeS formed at the interfaces and contributed to low friction and wear.However,under high von Mises stress,the film could not be stably retained and serious wear was obtained through direct contact of friction pairs.This illustrated that the evolution of the tribo-chemical reaction film was responsible for the anti-friction and anti-wearproperties of the DESs.展开更多
Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in si...Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in situ microscope to assist photoelectron spectroscopy.The configuration of long objective distance of 200 mm with two-mirror reflection has been introduced.Large magnification of 5×to 100×,lateral resolution of 4.08μm,and longitudinal resolution of 4.49μm have been achieved.Meanwhile,the testing result shows larger focal depth of this in situ optical microscope.Similar configurations could also be applied to other electronic microscopes to improve their probing capability.展开更多
Insulin secretion by pancreatic islets plays a vital role in regulating blood glucose levels.Nevertheless,the mech-anism responsible for this dynamic insulin secretion has not been completely understood,particularly a...Insulin secretion by pancreatic islets plays a vital role in regulating blood glucose levels.Nevertheless,the mech-anism responsible for this dynamic insulin secretion has not been completely understood,particularly at the single islet level.In this study,we have successfully developed an easy microfluidic platform that allows for the exploration of dynamic glucose-stimulated insulin secretion(GSIS)at the single islet level.With the utilization of this platform,we evaluated dynamic GSIS from single islets isolated from both normal and diabetic rats.Our results demonstrate that islets can be categorized into three types based on their dynamic GSIS:Type Ⅰ exhibits a biphasic GSIS profile with a fast first phase and flat second phase;Type Ⅱ also has a biphasic GSIS profile with a fast first phase but a slow increased second phase;Type Ⅲ displays only a slowly increased second phase and lacks a fast first phase.RNA sequencing analysis demonstrated that the cell type and exocytosis-specific genes are consistent with the proportion of cells and insulin release kinetics among the three types of islets,respectively.Moreover,our findings suggest that high expression of Atp5pb is anti-correlated with the first phase of insulin secretion.Furthermore,we revealed that diabetic islets exhibit only the type Ⅰ GSIS response,indicating a deliberate impairment of the second phase of insulin secretion.Together,this device serves as a crucial tool in the research field of islets and diabetes,allowing researchers to investigate islet functional heterogeneity and identity at the single islet level.展开更多
The identification of sensitive and specific biomarkers for Parkinson's disease(PD) poses an important clinical challenge. A potential biomarker for early diagnosis and disease monitoring of PD is region-specific ...The identification of sensitive and specific biomarkers for Parkinson's disease(PD) poses an important clinical challenge. A potential biomarker for early diagnosis and disease monitoring of PD is region-specific iron. Iron accumulation in the substantia nigra pars compacta is considered a main characteristic of PD.However, questions remain, such as the relationship between nigral iron and clinical indices of PD(motor impairment or disease duration). Further, previous studies have suggested the influence of iron on other nuclei. Iron quantification using magnetic resonance imaging(MRI)allows for studies of the relationship between regional iron and clinical symptoms in vivo. Thus, in this review we discuss the following topics: the technological development of MRI in measuring brain iron, nigral iron as a potential marker for PD in both clinical and prodromal stages, other influences of regional iron on PD, and clinical translation and future perspectives.展开更多
The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years.However, stimulated Raman scattering(SRS) is still a major factor limiting the further power scaling. Here,...The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years.However, stimulated Raman scattering(SRS) is still a major factor limiting the further power scaling. Here, we have demonstrated the mitigation of SRS in kilowatt-level diode-pumped fiber amplifiers using a chirped and tilted fiber Bragg grating(CTFBG) for the first time. The CTFBG is designed and inscribed in large-mode-area(LMA) fibers, matching with the operating wavelength of the fiber amplifier. With the CTFBG inserted between the seed laser and the amplifier stage, an SRS suppression ratio of ~10 dB is achieved in spectrum at the maximum output laser power of 2.35 kW,and there is no reduction in laser slope efficiency and degradation in beam quality. This work proves the feasibility and practicability of CTFBGs for SRS suppression in high-power fiber lasers, which is very useful for the further power scaling.展开更多
The average power of fiber lasers has been scaled deeply into the kW regime in the past years. However, stimulated Raman scattering(SRS) is still a major factor limiting further power scaling. Here, we have demonstrat...The average power of fiber lasers has been scaled deeply into the kW regime in the past years. However, stimulated Raman scattering(SRS) is still a major factor limiting further power scaling. Here, we have demonstrated for the first time, to the best of our knowledge, the suppression of SRS in a half 10 kW tandem pumping fiber amplifier using chirped and tilted fiber Bragg gratings(CTFBGs). With specially self-designed and manufactured CTFBGs inserted between the seed laser and the amplifier stage, a maximum SRS suppression ratio of >15 dB in spectrum is observed with no reduction in laser efficiency. With one CTFBG, the effective output power is improved to3.9 kW with a beam quality M2 factor of ～1.7 from <3.5 k W with an M2 factor of >2; with two CTFBGs, the effective laser power reaches 4.2 kW with an increasing ratio of 20% and an M2 factor of ～1.8, and further power improvement is limited by the power and performance of the 1018 nm pump sources. This work provides an effective SRS suppression method for high-power all-fiber lasers, which is useful for further power scaling of these systems.展开更多
We used resting-state fMRI to evaluate longitudinal alterations in local spontaneous brain activity in Parkinson's disease(PD) over a 2-year period. Data were acquired from 23 PD patients at baseline and follow-up...We used resting-state fMRI to evaluate longitudinal alterations in local spontaneous brain activity in Parkinson's disease(PD) over a 2-year period. Data were acquired from 23 PD patients at baseline and follow-up,and 27 age-and sex-matched normal controls. Regional homogeneity(ReHo) and voxel-based-morphometry(VBM) were used to identify differences in local spontaneous brain activity and grey matter volume. With disease progression, we observed a progressive decrease in ReHo in the sensorimotor cortex, default-mode network, and left cerebellum, but increased ReHo in the supplementary motor area, bilateral temporal gyrus, and hippocampus.Moreover, there was a significant positive correlation between the rates of ReHo change in the left cerebellum and the rates of change in the Unified Parkinson's Disease Rating Scale-III scores. VBM revealed no significant differences in the grey matter volume among the three sets of acquisitions. We conclude that ReHo may be a suitable non-invasive marker of progression in PD.展开更多
High-peak-power transform-limited narrow-linewidth nanosecond all-fiber lasers are desired in a range of applications.However,their linewidths will be broadened by self-phase modulation(SPM).We propose a novel concept...High-peak-power transform-limited narrow-linewidth nanosecond all-fiber lasers are desired in a range of applications.However,their linewidths will be broadened by self-phase modulation(SPM).We propose a novel concept that generates transform-limited laser pulses by temporally shaping the pulse seed.The impact of the pulse shape on SPM-induced spectral broadening was studied numerically and experimentally.It was found theoretically that the square-shape pulsed laser is immune to SPM-induced spectral broadening.Based on this principle,we built a high-peak-power,linearly polarized,square-shape nanosecond all-fiber laser in a master oscillator power amplifier(MOPA)configuration.Stimulated Brillouin scattering(SBS)limited peak powers of 4.02 kW,5.06 kW,6.52 kW and 9.30 kW were obtained at pulse widths of 8 ns,7 ns,6 ns and 5 ns.Thanks to the square-shape pulsed seed,the linewidths at maximum peak power remained at 129.5 MHz,137.6 MHz,156.2 MHz and 200.1 MHz,respectively,close to the transform-limited values of110.8 MHz,126.6 MHz,147.7 MHz and 177.3 MHz.展开更多
Power scaling based on traditional ytterbium-doped fibers(YDFs)is limited by optical nonlinear effects and transverse mode instability(TMI)in high-power fiber lasers.Here,we propose a novel long tapered fiber with a c...Power scaling based on traditional ytterbium-doped fibers(YDFs)is limited by optical nonlinear effects and transverse mode instability(TMI)in high-power fiber lasers.Here,we propose a novel long tapered fiber with a constant cladding and tapered core(CCTC)along its axis direction.The tapered-core region of the fiber is designed to enhance the stimulated Raman scattering(SRS)threshold and suppress higher-order mode resonance in the laser cavity.The CCTC YDF was fabricated successfully with a modified chemical vapor deposition(MCVD)method combined with solution doping technology,which has a cladding diameter of 400µm and a varying core with a diameter of~24μm at both ends and~31μm in the middle.To test the performance of the CCTC fiber during high-power operation,an all-fiber laser oscillator based on a CCTC YDF was investigated experimentally.As a result,a maximum output power of 3.42 kW was achieved with an optical-to-optical efficiency of 55.2%,although the TMI effect was observed at an output power of~3.12 kW.The measured beam quality(M^(2)factor)was~1.7,and no sign of the Raman component was observed in the spectrum.We believe that CCTC YDF has great potential to simultaneously mitigate the SRS and TMI effects,and further power scaling is promising by optimizing the structure of the YDF.展开更多
基金supported by the Doctoral Research Foundation of Bohai University (05013/0520bs006)the Science and Technology Project of“Unveiling and Commanding”Liaoning Province (2021JH1/10400033)the Scientific Research Project from Education Department of Liaoning Province (LJ2020010)。
文摘Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods.
基金supported by the National Natural Science Foundation of China [82172385 to H.S., 82172349 to Y.W.]the Key-Area Research and Development Program of Guangdong Province [2019B020236001 to H.S.]+3 种基金the Shenzhen Key Medical Discipline Construction Fund [ZDSYS20190902092851024 to H.S.]the Natural Science Foundation of Guangdong Province [2020A1515010097 to Z.X.]the Shenzhen Outstanding Science and Technology Innovation Talents-Outstanding Youth Fund project [RCYX20210706092106042 to Z.X.]Funding for open access charge:Shenzhen Key Medical Discipline Construction Fund。
文摘As the major cell precursors in osteogenesis, mesenchymal stem cells(MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversial. Composed of multiple constituent enhancers, super enhancers(SEs) are powerful cis-regulatory elements that identify genes that ensure sequential differentiation. The present study demonstrated that SEs were indispensable for MSC osteogenesis and involved in osteoporosis development. Through integrated analysis, we identified the most common SE-targeted and osteoporosis-related osteogenic gene,ZBTB16. ZBTB16, positively regulated by SEs, promoted MSC osteogenesis but was expressed at lower levels in osteoporosis.Mechanistically, SEs recruited bromodomain containing 4(BRD4) at the site of ZBTB16, which then bound to RNA polymerase IIassociated protein 2(RPAP2) that transported RNA polymerase Ⅱ(POL Ⅱ) into the nucleus. The subsequent synergistic regulation of POL Ⅱ carboxyterminal domain(CTD) phosphorylation by BRD4 and RPAP2 initiated ZBTB16 transcriptional elongation, which facilitated MSC osteogenesis via the key osteogenic transcription factor SP7. Bone-targeting ZBTB16 overexpression had a therapeutic effect on the decreased bone density and remodeling capacity of Brd4^(fl/fl)Prx1-cre mice and osteoporosis(OP) models.Therefore, our study shows that SEs orchestrate the osteogenesis of MSCs by targeting ZBTB16 expression, which provides an attractive focus and therapeutic target for osteoporosis.
基金supported by the National Natural Science Foundation of China(undergrant no.42122061)Macao Foundation+1 种基金the Project of Civil Aerospace“13th Five Year Plan”Preliminary Research in Space Science(grant nos.D020308 and D020301)the international partnership program of the Chinese Academy of Sciences(grant no.183311KYSB20200017)。
文摘The South Atlantic Anomaly(SAA)is a region where the geomagnetic field is significantly lower than that of the surrounding area.On the basis of the models of CHAOS-7.8,Mass Spectrometer Incoherent Scatter Model(NRLMSISE-00),and International Reference Ionosphere 2016(IRI-2016),we theoretically investigated the lower and upper boundaries of the ionospheric dynamo region inside the SAA.In the ionospheric dynamo region,electrons are coupled with magnetic field lines,whereas ions are decoupled from magnetic field lines.Our results showed that the ionospheric dynamo region inside the SAA is higher and larger than that outside the SAA.We also studied the boundary variations of the dynamo region inside the SAA depending on the seasons and solar activities.We found that the dynamo region inside the SAA is the highest and largest in the summer of the southern hemisphere at solar maximum.The larger and higher altitude range of the ionospheric dynamo region in the SAA can contribute to the stronger ionospheric currents in this region.
文摘Since the first laser was invented,the pursuit of high-energy lasers(HELs)has always been enthusiastic.The first revolution of HELs was pushed by the fusion of laser and aerospace in the 1960s,with the chemical rocket engines giving fresh impetus to the birth of gas flow and chemical lasers,which finally turned megawatt lasers from dream into reality.Nowadays,the development of HELs has entered the age of electricity as well as the rocket engines.The properties of current electric rocket engines are highly consistent with HELs’goals,including electrical driving,effective heat dissipation,little medium consumption and extremely light weight and size,which inspired a second fusion of laser and aerospace and motivated the exploration for potential HELs.As an exploratory attempt,a new configuration of diode pumped metastable rare gas laser was demonstrated,with the gain generator resembling an electric rocket-engine for improved power scaling ability.
文摘Objective: In this study, we aimed to estimate the updated incidence and mortality of primary bone cancers based on population-based cancer registration data in 2014, collected by the National Central Cancer Registry of China(NCCRC).Methods: In 2017, 339 registries' data were qualified based on data quality criteria set down by the NCCRC.Cases of primary bone cancers were retrieved from the national database. We estimated numbers of primary bone cancer cases and deaths in China using age-specific rates and corresponding national population stratified by area,sex, age-group(0, 1-4, 5-9, 10-14, …, 85+). Chinese standard population in 2000 and Segi's World population were applied for the calculation of age-standardized incidence and mortality rates.Results: In 2014, 24,000 primary bone cancer cases and 17,200 deaths attributable to primary bone cancers were estimated to have occurred in China. The crude incidence rate of primary bone cancers was 1.76/100,000, with agestandardized incidence rate by Chinese standard population(ASIRC) and by World standard population(ASIRW)being 1.35/100,000 and 1.32/100,000, respectively. The crude mortality rate of primary bone cancers was1.26/100,000, with age-standardized mortality rate by Chinese standard population(ASMRC) and by World standard population(ASMRW) being 0.88/100,000 and 0.86/100,000, respectively. Age-specific incidence curve was bimodally distributed with age, with the first peak occurring in the second decade of the life and the second peak in the elderly. Males had higher crude and age-standardized rates for both incidence and mortality compared with females. Both crude and age-standardized incidence rates were higher in rural areas than in urban areas, so were the crude and age-standardized mortality rates.Conclusions: This population-based study presents the most recently available estimates on primary bone cancers in China, revealing that the males are 1.34 times as much as females suffering from primary bone cancers and the adolescents in puberty and the elderly are predominantly affected groups by these cancers. High-quality cancer registration data are a prerequisite for undertaking further study for gaining insight into the causes and risk factors for primary bone cancers in China.
基金supported by Natural Science Foundation of Zhejiang Province(No.LR14C160001)National Natural Science Foundation(No.61190114,31370637,31500520)+3 种基金Joint Research fund of Department of Forestry of Zhejiang Province and Chinese Academy of Forestry(No.2017SY04)Key Discipline of Forestry of Creative Technology Project of Zhejiang Province(No.201511)Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-efficiency Utilization(No.S2017011)Startup Scientific Research Fund for Scholars of Zhejiang A&F University(No.2034020075)
文摘Bamboo forest is an important forest type in subtropical China and is characterized by fast growth and high carbon sequestration capacity. However, the dynamics of carbon fluxes during the fast growing period of bamboo shoots and their correlation with environment factors are poorly understood. We measured carbon dioxide exchange and climate variables using open-path eddy covariance methods during the 2011 growing season in a Moso bamboo forest(MB, Phyllostchys edulis) and a Lei bamboo forest(LB, Phyllostachys violascens) in Zhejiang province,China. The bamboo forests were carbon sinks during the growing season. The minimum diurnal net ecosystem exchange(NEE) at MB and LB sites were-0.64 and-0.66 mg C m^(-2) s^(-1), respectively. The minimum monthly NEE, ecosystem respiration(RE), and gross ecosystem exchange(GEE) were-99.3 ± 4.03, 76.2 ±2.46, and^(-1)91.5 ± 4.98 g C m^(-2) month^(-1), respectively,at MB site, compared with-31.8 ± 3.44, 70.4 ± 1.41,and^(-1)57.9 ± 4.86 g C m^(-2) month^(-1), respectively, at LB site. Maximum RE was 92.1 ± 1.32 g C m^(-2) month^(-1) at MB site and 151.0 ± 2.38 g C m^(-2) month^(-1) at LB site.Key control factors varied by month during the growing season, but across the whole growing season, NEE and GEE at both sites showed similar trends in sensitivities to photosynthetic active radiation and vapor pressure deficit,and air temperature had the strongest correlation with RE at both sites. Carbon fluxes at LB site were more sensitive to soil water content compared to those at MB site. Both onyear(years when many new shoots are produced) and offyear(years when none or few new shoots are produced)should be studied in bamboo forests to better understand their role in global carbon cycling.
基金Supported by Special Project of Fundamental Research Funds for Central Public Welfare Research Institutes in Chinese Academy of Tropical Agricultural Sciences(1630012015021)Project of Natural Science Foundation of Hainan Province(714282)
文摘The quality and safety crisis of agricultural products on the one hand is the crisis of harm of agricultural products,and on the other hand is the crisis of information dissemination. This paper analyzed the characteristics of content of the quality and safety crisis information of tropical agricultural products. On the basis of these characteristics,it came up with strategies and recommendations for solving the problems of quality and safety of tropical agricultural products,including establishing the emergency response system for quality and safety crisis of tropical agricultural products,bringing into play the social responsibilities of scientific research institutions,and bringing into play authoritative effect of scientific experts.
文摘The major impacts of climate change play a substantial role in triggering human migration, especially in the coastal areas. The individual or combined effects of climate change are likely to trigger mass human movement both within and across international borders. People rarely move for a single reason;the motivation to migrate is complex of many factors. The main goal of this article is to identify the factors related to the decision to migrate taken by refugees in the coastal area. To assess this objective we employ exploratory factor analysis and structural equation modeling (SEM) and find that different factors influence refugees’ migration decision differently. From the findings, it is seen that loss of shelter, extreme events, decreasing soil fertility and food shortage, variability in temperature patterns and exhaustion of natural resources are the most important environmental factors that affect the decision to migrate of climate refugees. Low income, increasing price, decreasing purchasing power are the most important economic factors that influence migration decision. No social factors have significant effect on migration decision while safety as a political factor has a moderate influence on refugees’ decision to migrate. Finally, this article provides some recommendations for recognition of and protection for migrants forced to move to safer places due to certain direct impacts of climate change, notwithstanding the existence of multi-causality.
基金funded by the Science and Technology Development Fund, Macao SAR (File no.0035/2018/AFJ)the National Natural Science Foundation of China (NSFC) under grants 41564007 and 41731067
文摘We perform a statistical analysis of data from the Mars Atmosphere and Volatile Evolution (MAVEN) project on the global distribution of protons in the Martian magnetosheath. Our results show that the proton number density distribution has a south-north asymmetry. This south-north asymmetry is most likely caused by the south-north asymmetric distributions of the crustal magnetic fields at Mars. The strong crustal magnetic fields push the inner boundary of magnetosheath to a higher altitude in the southern hemisphere. Due to the outward movement of the inner boundary of the magnetosheath, a compressed magnetosheath forms, causing subsequent increases in proton number density, thermal pressure, and total pressure. Eventually, a balance is reached between the increased total pressure inside the magnetosheath and the increased magnetic pressure inside the induced magnetosphere. Our statistical study suggests that the Martian crustal magnetic fields can strongly affect the proton number density distribution in the Martian magnetosheath.
基金funded by the Science and Technology Development Fund, Macao SAR (File no.0002/2019/A1)National Natural Science Foundation of China (NSFC) under grant 41731067supported by CNRS, CNES, Observatoire de Paris and Université Paul Sabatier, Toulouse
文摘The Martian hydrogen exosphere extends out of the bow shock, forming a "hydrogen corona". The solar wind interacts directly with the hydrogen corona. During an ICME event on 7 March 2015, the SWIA instrument onboard Mars Atmosphere and Volatile Evolution mission (MAVEN) observed that the pick-up H+ fluxes in upstream solar wind were enhanced. Also increased were the penetrating H+ fluxes in the Martian atmosphere. Quantitatively, these penetrating H+ fluxes cannot increase by a factor of 5 simply due to a factor of 3 increase in the solar wind density, suggesting that the increased abundance of exospheric hydrogen upstream of the bow shock was a consequence of the passage of the ICME. A denser outer hydrogen corona at high altitudes suggests that the expansion of the neutral atmosphere was caused by the ICME. The excited and heated hydrogen exosphere probably indicates an elevated hydrogen escape rate during an ICME.
文摘Based on the vehicle front crash finite element analysis, it shows that there is a large acceleration, so it needs further optimization. In order to improve the performance of vehicle collision, eight parts were selected which have large impact for the result, its thickness as design variables to the right of the B-pillar acceleration peak of optimization goal;17 sample points were selected by Latin hypercube sampling method. Many structure parameters are optimized using sequential quadratic program (SQP) based on the surrogate model. The results show that the improved RSM has high accuracy;the right B-pillar acceleration reduced approximately 22.8%, reached the expected objective and was more conducive to the occupant safety.
基金The authors acknowledge the supports from the National Natural Science Foundation of China(No.51805455)Sichuan Science and Technology Program(Nos.2019YFG0306 and 2019YFSY0012)the Fundamental Research Funds for the Central Universities(No.2682020CX04).
文摘Deep eutectic solvents(DESs)have been considered as novel and economic alternatives to traditional lubricants because of their similar physicochemical performance.In this study,choline chloride(ChCl)DESs were successfully synthesized via hydrogen-bonding networks of urea and thiourea as the hydrogen bond donors(HBDs).The as-synthesized ChCl-urea and ChCl-thiourea DESs had excellent thermal stability and displayed good lubrication between steel/steel tribo-pairs.The friction coefficient and wear rate of ChCl-thiourea DES were 50.1%and 80.6%,respectively,lower than those of ChCl-urea DES for GCr15/45 steel tribo-pairs.However,for GCr15/Q45 steel,ChCl-urea DES decreased the wear rate by 85.0%in comparison to ChCl-thiourea DES.Under ChCl-thiourea DES lubrication,the tribo-chemical reaction film composed of FeS formed at the interfaces and contributed to low friction and wear.However,under high von Mises stress,the film could not be stably retained and serious wear was obtained through direct contact of friction pairs.This illustrated that the evolution of the tribo-chemical reaction film was responsible for the anti-friction and anti-wearproperties of the DESs.
基金supported by the National Natural Science Foundation of China(No.11774427)。
文摘Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in situ microscope to assist photoelectron spectroscopy.The configuration of long objective distance of 200 mm with two-mirror reflection has been introduced.Large magnification of 5×to 100×,lateral resolution of 4.08μm,and longitudinal resolution of 4.49μm have been achieved.Meanwhile,the testing result shows larger focal depth of this in situ optical microscope.Similar configurations could also be applied to other electronic microscopes to improve their probing capability.
基金the financial supports from the National Key Research and Development Program of China(2020YFA0908200,2021YFA1101300)China Postdoctoral Science Foundation(2021M703418)technique support from Advanced Cell Technology Core facility and Imaging Core facility.
文摘Insulin secretion by pancreatic islets plays a vital role in regulating blood glucose levels.Nevertheless,the mech-anism responsible for this dynamic insulin secretion has not been completely understood,particularly at the single islet level.In this study,we have successfully developed an easy microfluidic platform that allows for the exploration of dynamic glucose-stimulated insulin secretion(GSIS)at the single islet level.With the utilization of this platform,we evaluated dynamic GSIS from single islets isolated from both normal and diabetic rats.Our results demonstrate that islets can be categorized into three types based on their dynamic GSIS:Type Ⅰ exhibits a biphasic GSIS profile with a fast first phase and flat second phase;Type Ⅱ also has a biphasic GSIS profile with a fast first phase but a slow increased second phase;Type Ⅲ displays only a slowly increased second phase and lacks a fast first phase.RNA sequencing analysis demonstrated that the cell type and exocytosis-specific genes are consistent with the proportion of cells and insulin release kinetics among the three types of islets,respectively.Moreover,our findings suggest that high expression of Atp5pb is anti-correlated with the first phase of insulin secretion.Furthermore,we revealed that diabetic islets exhibit only the type Ⅰ GSIS response,indicating a deliberate impairment of the second phase of insulin secretion.Together,this device serves as a crucial tool in the research field of islets and diabetes,allowing researchers to investigate islet functional heterogeneity and identity at the single islet level.
基金supported by the 13th Fiveyear Plan for the National Key Research and Development Program of China (2016YFC1306600)the Fundamental Research Funds for the Central Universities of China (2017XZZX001-01)+1 种基金the 12th Fiveyear Plan for the National Science and Technology Supporting Program of China (2012BAI10B04)the National Natural Science Foundation of China (81571654, 81371519, and 81301190)
文摘The identification of sensitive and specific biomarkers for Parkinson's disease(PD) poses an important clinical challenge. A potential biomarker for early diagnosis and disease monitoring of PD is region-specific iron. Iron accumulation in the substantia nigra pars compacta is considered a main characteristic of PD.However, questions remain, such as the relationship between nigral iron and clinical indices of PD(motor impairment or disease duration). Further, previous studies have suggested the influence of iron on other nuclei. Iron quantification using magnetic resonance imaging(MRI)allows for studies of the relationship between regional iron and clinical symptoms in vivo. Thus, in this review we discuss the following topics: the technological development of MRI in measuring brain iron, nigral iron as a potential marker for PD in both clinical and prodromal stages, other influences of regional iron on PD, and clinical translation and future perspectives.
基金supported by the National Natural Science Foundation of China(No.11274385)
文摘The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years.However, stimulated Raman scattering(SRS) is still a major factor limiting the further power scaling. Here, we have demonstrated the mitigation of SRS in kilowatt-level diode-pumped fiber amplifiers using a chirped and tilted fiber Bragg grating(CTFBG) for the first time. The CTFBG is designed and inscribed in large-mode-area(LMA) fibers, matching with the operating wavelength of the fiber amplifier. With the CTFBG inserted between the seed laser and the amplifier stage, an SRS suppression ratio of ~10 dB is achieved in spectrum at the maximum output laser power of 2.35 kW,and there is no reduction in laser slope efficiency and degradation in beam quality. This work proves the feasibility and practicability of CTFBGs for SRS suppression in high-power fiber lasers, which is very useful for the further power scaling.
基金National Natural Science Foundation of China(NSFC)(11274385)
文摘The average power of fiber lasers has been scaled deeply into the kW regime in the past years. However, stimulated Raman scattering(SRS) is still a major factor limiting further power scaling. Here, we have demonstrated for the first time, to the best of our knowledge, the suppression of SRS in a half 10 kW tandem pumping fiber amplifier using chirped and tilted fiber Bragg gratings(CTFBGs). With specially self-designed and manufactured CTFBGs inserted between the seed laser and the amplifier stage, a maximum SRS suppression ratio of >15 dB in spectrum is observed with no reduction in laser efficiency. With one CTFBG, the effective output power is improved to3.9 kW with a beam quality M2 factor of ～1.7 from <3.5 k W with an M2 factor of >2; with two CTFBGs, the effective laser power reaches 4.2 kW with an increasing ratio of 20% and an M2 factor of ～1.8, and further power improvement is limited by the power and performance of the 1018 nm pump sources. This work provides an effective SRS suppression method for high-power all-fiber lasers, which is useful for further power scaling of these systems.
基金supported by the 13th Five-year Plan for National Key Research and Development Program of China (2016YFC1306600)the 12th Five-year Plan for National Science and Technology Supporting Program of China (2012BAI10B04)the National Natural Science Foundation of China (81571654, 81371519, and 81301190)
文摘We used resting-state fMRI to evaluate longitudinal alterations in local spontaneous brain activity in Parkinson's disease(PD) over a 2-year period. Data were acquired from 23 PD patients at baseline and follow-up,and 27 age-and sex-matched normal controls. Regional homogeneity(ReHo) and voxel-based-morphometry(VBM) were used to identify differences in local spontaneous brain activity and grey matter volume. With disease progression, we observed a progressive decrease in ReHo in the sensorimotor cortex, default-mode network, and left cerebellum, but increased ReHo in the supplementary motor area, bilateral temporal gyrus, and hippocampus.Moreover, there was a significant positive correlation between the rates of ReHo change in the left cerebellum and the rates of change in the Unified Parkinson's Disease Rating Scale-III scores. VBM revealed no significant differences in the grey matter volume among the three sets of acquisitions. We conclude that ReHo may be a suitable non-invasive marker of progression in PD.
基金supported by the National Natural Science Foundation of China(Nos.61705265 and 61705264)the National Key R&D Programme of China(No.2017YFF0104603)the China Postdoctoral Science Foundation(No.2017M620070)
文摘High-peak-power transform-limited narrow-linewidth nanosecond all-fiber lasers are desired in a range of applications.However,their linewidths will be broadened by self-phase modulation(SPM).We propose a novel concept that generates transform-limited laser pulses by temporally shaping the pulse seed.The impact of the pulse shape on SPM-induced spectral broadening was studied numerically and experimentally.It was found theoretically that the square-shape pulsed laser is immune to SPM-induced spectral broadening.Based on this principle,we built a high-peak-power,linearly polarized,square-shape nanosecond all-fiber laser in a master oscillator power amplifier(MOPA)configuration.Stimulated Brillouin scattering(SBS)limited peak powers of 4.02 kW,5.06 kW,6.52 kW and 9.30 kW were obtained at pulse widths of 8 ns,7 ns,6 ns and 5 ns.Thanks to the square-shape pulsed seed,the linewidths at maximum peak power remained at 129.5 MHz,137.6 MHz,156.2 MHz and 200.1 MHz,respectively,close to the transform-limited values of110.8 MHz,126.6 MHz,147.7 MHz and 177.3 MHz.
基金the National Natural Science Foundation of China(Nos.61735007 and 61705266).
文摘Power scaling based on traditional ytterbium-doped fibers(YDFs)is limited by optical nonlinear effects and transverse mode instability(TMI)in high-power fiber lasers.Here,we propose a novel long tapered fiber with a constant cladding and tapered core(CCTC)along its axis direction.The tapered-core region of the fiber is designed to enhance the stimulated Raman scattering(SRS)threshold and suppress higher-order mode resonance in the laser cavity.The CCTC YDF was fabricated successfully with a modified chemical vapor deposition(MCVD)method combined with solution doping technology,which has a cladding diameter of 400µm and a varying core with a diameter of~24μm at both ends and~31μm in the middle.To test the performance of the CCTC fiber during high-power operation,an all-fiber laser oscillator based on a CCTC YDF was investigated experimentally.As a result,a maximum output power of 3.42 kW was achieved with an optical-to-optical efficiency of 55.2%,although the TMI effect was observed at an output power of~3.12 kW.The measured beam quality(M^(2)factor)was~1.7,and no sign of the Raman component was observed in the spectrum.We believe that CCTC YDF has great potential to simultaneously mitigate the SRS and TMI effects,and further power scaling is promising by optimizing the structure of the YDF.
