This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electric...This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electrical unit,have a total volume of 306 L and a total mass of 163.8 kg.These compact and robust units can overcome mechanical vibrations and temperature fluctuations during space launch.The laser sources of the optical unit are composed of diode lasers,and the injection locking of slave lasers is automatically performed by a program.In the experiment,a blue magneto-optical trap of cold atoms was achieved,with the atom numbers estimated to be approximately(1.50±0.13)×10^(6) for 87Sr and(8.00±0.56)×10^(6) for 88Sr.This work establishes a foundation for atomic confinement and high-precision interrogation in space-based optical clocks and expands the frontiers of cold atom physics in microgravity.展开更多
Immunomodulatory cancer therapy is witnessing the rise of viral immunotherapy.The oncolytic influenza A virus,although promising in preclinical investigations,remains to be implemented in clinical practice.Recent prog...Immunomodulatory cancer therapy is witnessing the rise of viral immunotherapy.The oncolytic influenza A virus,although promising in preclinical investigations,remains to be implemented in clinical practice.Recent progress in genetic engineering,coupled with experiential insights,offers opportunities to enhance the therapeutic efficacy of the influenza A virus.This review explores the use of the influenza virus,its attenuated forms,and associated vaccines in cancer immunotherapy,highlighting their respective advantages and challenges.We further elucidate methods for engineering influenza viruses and innovative approaches to augment them with cytokines or immune checkpoint inhibitors,aiming to maximize their clinical impact.Our goal is to provide insights essential for refining influenza A virus-based viral tumor immunotherapies.展开更多
Autophagy is a conserved intracellular degradation system that plays a dual role in cell death;thus,therapies targeting autophagy in cancer are somewhat controversial.Ferroptosis is a new form of regulated cell death ...Autophagy is a conserved intracellular degradation system that plays a dual role in cell death;thus,therapies targeting autophagy in cancer are somewhat controversial.Ferroptosis is a new form of regulated cell death featured with the iron-dependent accumulation of lethal lipid ROS.This pathway is morphologically,biochemically and genetically distinct from other forms of cell death.Accumulating studies have revealed crosstalk between autophagy and ferroptosis at the molecular level.In this review,we summarize the mechanisms of ferroptosis and autophagy,and more importantly,their roles in the drug resistance of cancer.Numerous connections between ferroptosis and autophagy have been revealed,and a strong causal relationship exists wherein one process controls the other and can be utilized as potential therapeutic targets for cancer.The elucidation of when and how to modulate their crosstalk using therapeutic strategies depends on an understanding of the fine-tuned switch between ferroptosis and autophagy,and approaches designed to manipulate the intensity of autophagy might be the key.展开更多
With the progress of society, there is an increasing need to tackle disorders of the central nervous system. Human brain tissue, unlike animal tissues, is an irreplaceable resource for the study of neurological diseas...With the progress of society, there is an increasing need to tackle disorders of the central nervous system. Human brain tissue, unlike animal tissues, is an irreplaceable resource for the study of neurological diseases (1)Aimed at scientific research and education, the roles of human brain tissue repositories are to acquire brain tissue from donors, prepare, process, and preserve collected samples,provide tissue to specific eligible facilities, and determine the characteristics of each tissue sample.展开更多
We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord trans...We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord transection injury. After 2 weeks, the number of neurons and BrdU-positive cells in the Nogo-66 receptor gene silencing group was higher than in the bone marrow mesenchymal stem cell group, and significantly greater compared with the model group. After 4 weeks, behavioral performance was signiifcantly enhanced in the model group. Af-ter 8 weeks, the number of horseradish peroxidase-labeled nerve ifbers was higher in the Nogo-66 receptor gene silencing group than in the bone marrow mesenchymal stem cell group, and signiifcantly higher than in the model group. The newly formed nerve ifbers and myelinated ner ve ifbers were detectable in the central transverse plane section in the bone marrow mesenchymal stem cell group and in the Nogo-66 receptor gene silencing group.展开更多
A group of Cu（Zr）-based bulk metallic glasses （BMGs） with critical diameter （De） in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14...A group of Cu（Zr）-based bulk metallic glasses （BMGs） with critical diameter （De） in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14 mm was established for Cu-based compositions, and 16 mm for compositions based on equi-atomic CuZr. Additional partial substitution of Hf for Zr further elevated the Dc to 18 mm at Cu42Zr43Hf1.5Y3.5Al10.展开更多
In this work,bending fatigue behavior of thinner Zr_(61)Ti_(2)Cu_(25)Al_(12)(ZT1)BMG beams with thicknesses of 500μm and 100μm were investigated with three-point bending(3PB),to evaluate the reliability and safety o...In this work,bending fatigue behavior of thinner Zr_(61)Ti_(2)Cu_(25)Al_(12)(ZT1)BMG beams with thicknesses of 500μm and 100μm were investigated with three-point bending(3PB),to evaluate the reliability and safety of this potentially material used in compliant mechanisms under cyclic bending load.Fatigue endurance limits(FELs)of ZT1 beams with thicknesses of 500μm and 100μm were determined to be 470 MPa,and~0.3 of its tensile strength.Fatigue life and FEL of ZT1 beams in bending are substantially independent of the beam thickness,in the scale from 500μm down to 100μm.Fatigue cracks of all ZT1 beams initiated at the extrinsic microvoids,either indirectly derived from surface scratches during mechanical polishing or originated from as-cast process.However,fatigue crack propagation behavior is highly related to the magnitude of cyclic stress level.By interrupted fatigue tests,larger proportion about 60-70%of fatigue life was spent on crack propagation under high stress level,while crack initiation occupied larger proportion about 80-85%under low stress level.The medium stress level of about 590 MPa almost shared the crack-initiation life and crack-propagation life.In addition,there are two crack deflection mechanisms during cracks steady propagation stage.One mechanism is crack deflection along the interacted shear bands ahead of crack-tip,the other one is crack"jump"from one shear band to another shear band at a certain angle.These two mechanisms alternate dominate the crack propagation process,generating typical staircase-like crack propagation trajectory.Fatigue endurance limits of ZT1 beams in the form of either stress amplitude or strain amplitude are superior to traditional candidate materials in the field of compliant mechanisms,showing that the better reliability and larger deflection deformation can be achieved for flexible members made by ZT1 BMG even under cyclic loading.展开更多
Alzheimer's disease(AD) is the most common form of dementia in elderly with major symptoms of a general term for memory loss and other intellectual abilities impairment which are serious enough to interfere with d...Alzheimer's disease(AD) is the most common form of dementia in elderly with major symptoms of a general term for memory loss and other intellectual abilities impairment which are serious enough to interfere with daily life.While there is no treatment can prevent and revise the cognitive function impairment in AD,physical activity becomes a potential beneficia intervention for AD.Multiple evidences suggested that exercise in general plays beneficia roles in improving brain function.Most common mechanisms of exercise-induced enhancement of brain function are including alteration of neurogenesis,neuron plasticity,neuronal signaling and receptors,as well as neuronal networks.This mini review includes most recent clinical studies and focuses on the effects of physical exercise,cognitive stimulation,and combination of both physical and cognitive training on protection and rescue cognitive decline in people with AD.展开更多
The fully developed turbulence can be regarded as a nonlinear system,with wave coupling inside,which causes the nonlinear energy to transfer,and drives the turbulence to develop further or be suppressed.Spectral analy...The fully developed turbulence can be regarded as a nonlinear system,with wave coupling inside,which causes the nonlinear energy to transfer,and drives the turbulence to develop further or be suppressed.Spectral analysis is one of the most effective methods to study turbulence system.In order to apply it to the study of the nonlinear wave coupling process of edge plasma turbulence,an efficient algorithm based on spectral analysis technology is proposed to solve the nonlinear wave coupling equation.The algorithm is based on a mandatory temporal static condition with the nonideal spectra separated from the ideal spectra.The realization idea and programing flow are given.According to the characteristics of plasma turbulence,the simulation data are constructed and used to verify the algorithm and its implementation program.The simulation results and experimental results show the accuracy of the algorithm and the corresponding program,which can play a great role in the studying the energy transfer in edge plasma turbulences.As an application,the energy cascade analysis of typical edge plasma turbulence is carried out by using the results of a case calculation.Consequently,a physical picture of the energy transfer in a kind of fully developed turbulence is constructed,which confirms that the energy transfer in this turbulent system develops from lower-frequency region to higher-frequency region and from linear growing wave to damping wave.展开更多
BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evalua...BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evaluate the clinical efficacy of peritoneal drainage in very-low-birth-weight(VLBW)neonates with modified Bell’s stage II NEC.METHODS This was a retrospective analysis of 102 NEC(modified Bell’s stage II)neonates born with VLBW who were treated at the Fujian Children’s Hospital(Fujian Branch of Shanghai Children’s Medical Center)between January 2017 and January 2020;these included 24 cases in the peritoneal drainage group,36 cases in the exploratory laparotomy group,and 42 cases in the conservative treatment group.RESULTS The general characteristics were comparable in the three groups(P>0.05).Compared with conservative treatment,peritoneal drainage was associated with significantly shorter fasting time,abdominal distension relief time,fecal occult blood(OB)negative conversion time,and reduced hospital length of stay(HLOS)(P<0.05 for all).Despite some advantages of peritoneal drainage over conservative treatment in terms of cure,conversion to laparotomy,intestinal perforation,intestinal stenosis,and abdominal abscess rates,the differences were not statistically significant(P>0.05).Compared to exploratory laparotomy,the fecal OB negative conversion time was significantly shorter in the peritoneal drainage group(P<0.05);similarly,the exploratory laparotomy group showed longer fasting time,abdominal distension relief time,HLOS,and higher complication rate compared to peritoneal drainage group,but the between-group differences were not statistically significant(P>0.05).CONCLUSION Peritoneal drainage,an easy-to-operate procedure,can improve the clinical symptoms of VLBW neonates with Bell’s stage II NEC and help reduce the HLOS.展开更多
Four new diterpenoid alkaloids,nagaconitines A-D（1-4）,were isolated from the roots of Aconitum nagarum var.heterotrichum.Their structures were elucidated as 8-（4＇-hydroxylbutyryl） aconitine（1）,15-oxo-13-deoxylu...Four new diterpenoid alkaloids,nagaconitines A-D（1-4）,were isolated from the roots of Aconitum nagarum var.heterotrichum.Their structures were elucidated as 8-（4＇-hydroxylbutyryl） aconitine（1）,15-oxo-13-deoxyludaconitine（2）,15-hydroxyldelphisine（3）,and 14-hydroxyl-2- acetoxyspiradine C（4）based on extensive UV,IR,MS,1D NMR and 2D NMR analyses.Compounds 3-4 showed inhibition of cancer cell line SK-OV-3 with 31%（IC_（50） 43.78 μmol/L） and 24%（IC_（50） 32.14 μmol/L）,respectively.展开更多
Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in ...Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.展开更多
Background： Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate（HMB） could improve the performance of weaning pigs, but there were little information in the muscle fi...Background： Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate（HMB） could improve the performance of weaning pigs, but there were little information in the muscle fiber type transformation of the offspring and the subsequent performance in pigs from weaning through finishing in response to maternal HMB consumption. The purpose of this study was to determine the effect of supplementing lactating sows with HMB on skeletal muscle fiber type transformation and growth of the offspring during d 28 and180 after birth. A total of 20 sows according to their body weight were divided into the control（CON, n = 10） or HMB groups（HMB, n = 10）. Sows in the HMB group were supplemented with β-hydroxy-β-methylbutyrate calcium（HMB-Ca） 2 g/kg feed during d 1 to 27 of lactation. After weaning, 48 mixed sex piglets were blocked by sow treatment and fed standard diets for post-weaning, growing, finishing periods. Growth performance was recorded during d 28 to 180 after birth. Pigs were slaughtered on d 28（n = 6/treatment） and 180（n = 6/treatment） postnatal and the longissimus dorsi（LD） was collected, respectively.Results： The HMB-fed sows during lactation showed increased HMB concentration（P ＆lt; 0.05） in milk and LD of weaning piglets（P ＆lt; 0.05）. In addition, offsprings in HMB group had a higher finishing BW and lean percentage than did pigs in CON group（P ＆lt; 0.05）, meanwhile, compared with pigs from sows fed the CON diet, pigs from sows fed HMB diet showed higher type Ⅱ muscle fiber cross-sectional area（CSA）, elevated myosin heavy chain（MyHC） Ⅱb and Sox6 mRNA, and fast-MyHC protein levels in LD（P ＆lt; 0.05）.Conclusions： HMB supplemented to sow diets throughout lactation increases the levels of HMB in maternal milk and skeletal muscle of pigs during d 28 after birth and promotes subsequent performance of pigs between d 28 and 180 of age by enhancing glycolytic muscle fiber transformation.展开更多
Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. S...Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization（SI-ROP） of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.展开更多
Nanoporous metals have attracted signifi cant attention owing to their excellent physical,chemical,and biological properties.However,preparing ultrafi ne nanoporous metal particles(1–5μm)with specifi c geometries re...Nanoporous metals have attracted signifi cant attention owing to their excellent physical,chemical,and biological properties.However,preparing ultrafi ne nanoporous metal particles(1–5μm)with specifi c geometries remains challenging.Herein,we report a simple strategy to prepare ultrafi ne fl aky hexagonal nanoporous Au-Cu and Au particles via dealloying.Mg-based alloy ribbons with ultrafi ne fl aky hexagonal Mg-Au(Cu)-Gd particles dispersed in a Mg-Cu(Au)-Gd metallic glassy matrix were prepared.The size and morphology of the precipitated fl aky hexagonal Mg-Au(Cu)-Gd particles were controlled by the solidifi cation process of a Mg 61 Cu 21 Au 7 Gd 11 alloy melt.Ultrafi ne fl aky hexagonal nanoporous Au-Cu particles(diagonal diameter 2.58±0.44μm,ligament size~28 nm),Au-1 particles(diagonal diameter 2.38±0.35μm,ligament size~83 nm)and Au-2 particles(diagonal diameter 2.39±0.44μm,ligament size~66 nm)were prepared via ultrasonic-assisted dealloying of Mg 61 Cu 21 Au 7 Gd 11 alloy ribbons in 0.25 M HCl/ethanol,1 M HCl/ethanol and 0.25 M HNO 3/ethanol solutions,respectively.The ultrafi ne fl aky hexagonal nanoporous Au-Cu and Au particles with a large specifi c surface area have a uniform particle size and shape,implying that they possess adequate powder fl uidity and excellent catalytic properties.Moreover,the formation mechanism of the MgAu(Cu)Gd phase in solidifi ed Mg-Cu-Au-Gd alloys was discussed.This study provides a novel approach for synthesizing nanoporous metal particles with a specifi c geometry.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB35010202)the National Natural Science Foundation of China(Grants No.62275268)。
文摘This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electrical unit,have a total volume of 306 L and a total mass of 163.8 kg.These compact and robust units can overcome mechanical vibrations and temperature fluctuations during space launch.The laser sources of the optical unit are composed of diode lasers,and the injection locking of slave lasers is automatically performed by a program.In the experiment,a blue magneto-optical trap of cold atoms was achieved,with the atom numbers estimated to be approximately(1.50±0.13)×10^(6) for 87Sr and(8.00±0.56)×10^(6) for 88Sr.This work establishes a foundation for atomic confinement and high-precision interrogation in space-based optical clocks and expands the frontiers of cold atom physics in microgravity.
基金supported by the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2022R01002)the National Natural Science Foundation of China(Nos.82272300 and 82102893)the Fundamental Research Funds for the Central Universities(No.226-2024-00062),China.
文摘Immunomodulatory cancer therapy is witnessing the rise of viral immunotherapy.The oncolytic influenza A virus,although promising in preclinical investigations,remains to be implemented in clinical practice.Recent progress in genetic engineering,coupled with experiential insights,offers opportunities to enhance the therapeutic efficacy of the influenza A virus.This review explores the use of the influenza virus,its attenuated forms,and associated vaccines in cancer immunotherapy,highlighting their respective advantages and challenges.We further elucidate methods for engineering influenza viruses and innovative approaches to augment them with cytokines or immune checkpoint inhibitors,aiming to maximize their clinical impact.Our goal is to provide insights essential for refining influenza A virus-based viral tumor immunotherapies.
基金supported by the National Natural Science Foundation of China (Grant No. 81602471, 81672729, 81672729, 81874380 and 81672932)Zhejiang Provincial Natural Science Foundation of China under Grants (Grant No. LY19H160055, LY19H160059)+5 种基金by Zheng Shu Medical Elite Scholarship Fundby grant from sub-project of China National Program on Key Basic Research Project (973 Program) (Grant No. 2014CB744505)Zhejiang Provincial Natural Science Foundation of China for Distinguished Young Scholars (Grant No. LR18H160001)Zhejiang Province Medical Science and Technology Project (Grant No. 2017RC007)Talent Project of Zhejiang Association for Science and Technology (Grant No. 2017YCGC002)Zhejiang Province Science and Technology Project of TCM (Grant No. 2019ZZ016)
文摘Autophagy is a conserved intracellular degradation system that plays a dual role in cell death;thus,therapies targeting autophagy in cancer are somewhat controversial.Ferroptosis is a new form of regulated cell death featured with the iron-dependent accumulation of lethal lipid ROS.This pathway is morphologically,biochemically and genetically distinct from other forms of cell death.Accumulating studies have revealed crosstalk between autophagy and ferroptosis at the molecular level.In this review,we summarize the mechanisms of ferroptosis and autophagy,and more importantly,their roles in the drug resistance of cancer.Numerous connections between ferroptosis and autophagy have been revealed,and a strong causal relationship exists wherein one process controls the other and can be utilized as potential therapeutic targets for cancer.The elucidation of when and how to modulate their crosstalk using therapeutic strategies depends on an understanding of the fine-tuned switch between ferroptosis and autophagy,and approaches designed to manipulate the intensity of autophagy might be the key.
文摘With the progress of society, there is an increasing need to tackle disorders of the central nervous system. Human brain tissue, unlike animal tissues, is an irreplaceable resource for the study of neurological diseases (1)Aimed at scientific research and education, the roles of human brain tissue repositories are to acquire brain tissue from donors, prepare, process, and preserve collected samples,provide tissue to specific eligible facilities, and determine the characteristics of each tissue sample.
文摘We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord transection injury. After 2 weeks, the number of neurons and BrdU-positive cells in the Nogo-66 receptor gene silencing group was higher than in the bone marrow mesenchymal stem cell group, and significantly greater compared with the model group. After 4 weeks, behavioral performance was signiifcantly enhanced in the model group. Af-ter 8 weeks, the number of horseradish peroxidase-labeled nerve ifbers was higher in the Nogo-66 receptor gene silencing group than in the bone marrow mesenchymal stem cell group, and signiifcantly higher than in the model group. The newly formed nerve ifbers and myelinated ner ve ifbers were detectable in the central transverse plane section in the bone marrow mesenchymal stem cell group and in the Nogo-66 receptor gene silencing group.
基金supported by the National Natural Science Foundation of China under Grants Nos.50671105 and 50621091.
文摘A group of Cu（Zr）-based bulk metallic glasses （BMGs） with critical diameter （De） in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14 mm was established for Cu-based compositions, and 16 mm for compositions based on equi-atomic CuZr. Additional partial substitution of Hf for Zr further elevated the Dc to 18 mm at Cu42Zr43Hf1.5Y3.5Al10.
基金supported by the National Natural Science Foundation of China under Grant No.51571192。
文摘In this work,bending fatigue behavior of thinner Zr_(61)Ti_(2)Cu_(25)Al_(12)(ZT1)BMG beams with thicknesses of 500μm and 100μm were investigated with three-point bending(3PB),to evaluate the reliability and safety of this potentially material used in compliant mechanisms under cyclic bending load.Fatigue endurance limits(FELs)of ZT1 beams with thicknesses of 500μm and 100μm were determined to be 470 MPa,and~0.3 of its tensile strength.Fatigue life and FEL of ZT1 beams in bending are substantially independent of the beam thickness,in the scale from 500μm down to 100μm.Fatigue cracks of all ZT1 beams initiated at the extrinsic microvoids,either indirectly derived from surface scratches during mechanical polishing or originated from as-cast process.However,fatigue crack propagation behavior is highly related to the magnitude of cyclic stress level.By interrupted fatigue tests,larger proportion about 60-70%of fatigue life was spent on crack propagation under high stress level,while crack initiation occupied larger proportion about 80-85%under low stress level.The medium stress level of about 590 MPa almost shared the crack-initiation life and crack-propagation life.In addition,there are two crack deflection mechanisms during cracks steady propagation stage.One mechanism is crack deflection along the interacted shear bands ahead of crack-tip,the other one is crack"jump"from one shear band to another shear band at a certain angle.These two mechanisms alternate dominate the crack propagation process,generating typical staircase-like crack propagation trajectory.Fatigue endurance limits of ZT1 beams in the form of either stress amplitude or strain amplitude are superior to traditional candidate materials in the field of compliant mechanisms,showing that the better reliability and larger deflection deformation can be achieved for flexible members made by ZT1 BMG even under cyclic loading.
文摘Alzheimer's disease(AD) is the most common form of dementia in elderly with major symptoms of a general term for memory loss and other intellectual abilities impairment which are serious enough to interfere with daily life.While there is no treatment can prevent and revise the cognitive function impairment in AD,physical activity becomes a potential beneficia intervention for AD.Multiple evidences suggested that exercise in general plays beneficia roles in improving brain function.Most common mechanisms of exercise-induced enhancement of brain function are including alteration of neurogenesis,neuron plasticity,neuronal signaling and receptors,as well as neuronal networks.This mini review includes most recent clinical studies and focuses on the effects of physical exercise,cognitive stimulation,and combination of both physical and cognitive training on protection and rescue cognitive decline in people with AD.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFE0301200)the National Natural Science Foundation of China(Grant Nos.12075077 and 12175055)the Science and Technology Project of Sichuan Pprovince,China(Grant No.2020YJ0464)。
文摘The fully developed turbulence can be regarded as a nonlinear system,with wave coupling inside,which causes the nonlinear energy to transfer,and drives the turbulence to develop further or be suppressed.Spectral analysis is one of the most effective methods to study turbulence system.In order to apply it to the study of the nonlinear wave coupling process of edge plasma turbulence,an efficient algorithm based on spectral analysis technology is proposed to solve the nonlinear wave coupling equation.The algorithm is based on a mandatory temporal static condition with the nonideal spectra separated from the ideal spectra.The realization idea and programing flow are given.According to the characteristics of plasma turbulence,the simulation data are constructed and used to verify the algorithm and its implementation program.The simulation results and experimental results show the accuracy of the algorithm and the corresponding program,which can play a great role in the studying the energy transfer in edge plasma turbulences.As an application,the energy cascade analysis of typical edge plasma turbulence is carried out by using the results of a case calculation.Consequently,a physical picture of the energy transfer in a kind of fully developed turbulence is constructed,which confirms that the energy transfer in this turbulent system develops from lower-frequency region to higher-frequency region and from linear growing wave to damping wave.
文摘BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evaluate the clinical efficacy of peritoneal drainage in very-low-birth-weight(VLBW)neonates with modified Bell’s stage II NEC.METHODS This was a retrospective analysis of 102 NEC(modified Bell’s stage II)neonates born with VLBW who were treated at the Fujian Children’s Hospital(Fujian Branch of Shanghai Children’s Medical Center)between January 2017 and January 2020;these included 24 cases in the peritoneal drainage group,36 cases in the exploratory laparotomy group,and 42 cases in the conservative treatment group.RESULTS The general characteristics were comparable in the three groups(P>0.05).Compared with conservative treatment,peritoneal drainage was associated with significantly shorter fasting time,abdominal distension relief time,fecal occult blood(OB)negative conversion time,and reduced hospital length of stay(HLOS)(P<0.05 for all).Despite some advantages of peritoneal drainage over conservative treatment in terms of cure,conversion to laparotomy,intestinal perforation,intestinal stenosis,and abdominal abscess rates,the differences were not statistically significant(P>0.05).Compared to exploratory laparotomy,the fecal OB negative conversion time was significantly shorter in the peritoneal drainage group(P<0.05);similarly,the exploratory laparotomy group showed longer fasting time,abdominal distension relief time,HLOS,and higher complication rate compared to peritoneal drainage group,but the between-group differences were not statistically significant(P>0.05).CONCLUSION Peritoneal drainage,an easy-to-operate procedure,can improve the clinical symptoms of VLBW neonates with Bell’s stage II NEC and help reduce the HLOS.
基金supported by the National Natural Science Foundation of China (Nos. 21362045, 81560622)the project of Sciences and Technology Department of Yunnan Province (No. 2012CG007)
文摘Four new diterpenoid alkaloids,nagaconitines A-D（1-4）,were isolated from the roots of Aconitum nagarum var.heterotrichum.Their structures were elucidated as 8-（4＇-hydroxylbutyryl） aconitine（1）,15-oxo-13-deoxyludaconitine（2）,15-hydroxyldelphisine（3）,and 14-hydroxyl-2- acetoxyspiradine C（4）based on extensive UV,IR,MS,1D NMR and 2D NMR analyses.Compounds 3-4 showed inhibition of cancer cell line SK-OV-3 with 31%（IC_（50） 43.78 μmol/L） and 24%（IC_（50） 32.14 μmol/L）,respectively.
基金The National Natural Science Foundation of China(Grant No.11274172)supported this work.
文摘Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.
基金supported by the National Special Research Fund for Non-Profit Sector(Agriculture)(No.201203015)Academy of Kechuang Feed Industry in Sichuan(2013NZ0056)+1 种基金Research Team of Youth Scientific and Technical Innovation of Sichuan(13CXTD0004)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13083)
文摘Background： Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate（HMB） could improve the performance of weaning pigs, but there were little information in the muscle fiber type transformation of the offspring and the subsequent performance in pigs from weaning through finishing in response to maternal HMB consumption. The purpose of this study was to determine the effect of supplementing lactating sows with HMB on skeletal muscle fiber type transformation and growth of the offspring during d 28 and180 after birth. A total of 20 sows according to their body weight were divided into the control（CON, n = 10） or HMB groups（HMB, n = 10）. Sows in the HMB group were supplemented with β-hydroxy-β-methylbutyrate calcium（HMB-Ca） 2 g/kg feed during d 1 to 27 of lactation. After weaning, 48 mixed sex piglets were blocked by sow treatment and fed standard diets for post-weaning, growing, finishing periods. Growth performance was recorded during d 28 to 180 after birth. Pigs were slaughtered on d 28（n = 6/treatment） and 180（n = 6/treatment） postnatal and the longissimus dorsi（LD） was collected, respectively.Results： The HMB-fed sows during lactation showed increased HMB concentration（P ＆lt; 0.05） in milk and LD of weaning piglets（P ＆lt; 0.05）. In addition, offsprings in HMB group had a higher finishing BW and lean percentage than did pigs in CON group（P ＆lt; 0.05）, meanwhile, compared with pigs from sows fed the CON diet, pigs from sows fed HMB diet showed higher type Ⅱ muscle fiber cross-sectional area（CSA）, elevated myosin heavy chain（MyHC） Ⅱb and Sox6 mRNA, and fast-MyHC protein levels in LD（P ＆lt; 0.05）.Conclusions： HMB supplemented to sow diets throughout lactation increases the levels of HMB in maternal milk and skeletal muscle of pigs during d 28 after birth and promotes subsequent performance of pigs between d 28 and 180 of age by enhancing glycolytic muscle fiber transformation.
基金financially supported by the Sino-Swiss Science and Technology Cooperation(No.EG41-092011)as well as the Chinese Academy of Sciences(Visiting Professorship for Senior International Scientists to H.A.K.)
文摘Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization（SI-ROP） of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3800504)the Tianshan Innovation Team Program of Xinjiang Uygur Autonomous Region(Grand No.2020D14038)+1 种基金the Department of Education of Guangdong in China(Nos.2021KCXTD050,2018KZDXM069)the National Natural Science Foundation of China(Grant No.51871056)。
文摘Nanoporous metals have attracted signifi cant attention owing to their excellent physical,chemical,and biological properties.However,preparing ultrafi ne nanoporous metal particles(1–5μm)with specifi c geometries remains challenging.Herein,we report a simple strategy to prepare ultrafi ne fl aky hexagonal nanoporous Au-Cu and Au particles via dealloying.Mg-based alloy ribbons with ultrafi ne fl aky hexagonal Mg-Au(Cu)-Gd particles dispersed in a Mg-Cu(Au)-Gd metallic glassy matrix were prepared.The size and morphology of the precipitated fl aky hexagonal Mg-Au(Cu)-Gd particles were controlled by the solidifi cation process of a Mg 61 Cu 21 Au 7 Gd 11 alloy melt.Ultrafi ne fl aky hexagonal nanoporous Au-Cu particles(diagonal diameter 2.58±0.44μm,ligament size~28 nm),Au-1 particles(diagonal diameter 2.38±0.35μm,ligament size~83 nm)and Au-2 particles(diagonal diameter 2.39±0.44μm,ligament size~66 nm)were prepared via ultrasonic-assisted dealloying of Mg 61 Cu 21 Au 7 Gd 11 alloy ribbons in 0.25 M HCl/ethanol,1 M HCl/ethanol and 0.25 M HNO 3/ethanol solutions,respectively.The ultrafi ne fl aky hexagonal nanoporous Au-Cu and Au particles with a large specifi c surface area have a uniform particle size and shape,implying that they possess adequate powder fl uidity and excellent catalytic properties.Moreover,the formation mechanism of the MgAu(Cu)Gd phase in solidifi ed Mg-Cu-Au-Gd alloys was discussed.This study provides a novel approach for synthesizing nanoporous metal particles with a specifi c geometry.
