To understand the strengths of rocks under complex stress states,a generalized nonlinear threedimensional(3D)Hoek‒Brown failure(NGHB)criterion was proposed in this study.This criterion shares the same parameters with ...To understand the strengths of rocks under complex stress states,a generalized nonlinear threedimensional(3D)Hoek‒Brown failure(NGHB)criterion was proposed in this study.This criterion shares the same parameters with the generalized HB(GHB)criterion and inherits the parameter advantages of GHB.Two new parameters,b,and n,were introduced into the NGHB criterion that primarily controls the deviatoric plane shape of the NGHB criterion under triaxial tension and compression,respectively.The NGHB criterion can consider the influence of intermediate principal stress(IPS),where the deviatoric plane shape satisfies the smoothness requirements,while the HB criterion not.This criterion can degenerate into the two modified 3D HB criteria,the Priest criterion under triaxial compression condition and the HB criterion under triaxial compression and tension condition.This criterion was verified using true triaxial test data for different parameters,six types of rocks,and two kinds of in situ rock masses.For comparison,three existing 3D HB criteria were selected for performance comparison research.The result showed that the NGHB criterion gave better prediction performance than other criteria.The prediction errors of the strength of six types of rocks and two kinds of in situ rock masses were in the range of 2.0724%-3.5091%and 1.0144%-3.2321%,respectively.The proposed criterion lays a preliminary theoretical foundation for prediction of engineering rock mass strength under complex in situ stress conditions.展开更多
Strength theory is the basic theory for calculating and designing the strength of engineering materials in civil,hydraulic,mechanical,aerospace,military,and other engineering disciplines.Therefore,the comprehensive st...Strength theory is the basic theory for calculating and designing the strength of engineering materials in civil,hydraulic,mechanical,aerospace,military,and other engineering disciplines.Therefore,the comprehensive study of the generalized nonlinear strength theory(GNST)of geomaterials has significance for the construction of engineering rock strength.This paper reviews the GNST of geomaterials to demonstrate the research status of nonlinear strength characteristics of geomaterials under complex stress paths.First,it systematically summarizes the research progress of GNST(classical and empirical criteria).Then,the latest research the authors conducted over the past five years on the GNST is introduced,and a generalized three-dimensional(3D)nonlinear Hoek‒Brown(HB)criterion(NGHB criterion)is proposed for practical applications.This criterion can be degenerated into the existing three modified HB criteria and has a better prediction performance.The strength prediction errors for six rocks and two in-situ rock masses are 2.0724%-3.5091%and 1.0144%-3.2321%,respectively.Finally,the development and outlook of the GNST are expounded,and a new topic about the building strength index of rock mass and determining the strength of in-situ engineering rock mass is proposed.The summarization of the GNST provides theoretical traceability and optimization for constructing in-situ engineering rock mass strength.展开更多
Measurements of carbon dioxide(CO_(2)),methane(CH_(4)),and carbon monoxide(CO)are of great importance in the Qinghai-Tibetan region,as it is the highest and largest plateau in the world affecting global weather and cl...Measurements of carbon dioxide(CO_(2)),methane(CH_(4)),and carbon monoxide(CO)are of great importance in the Qinghai-Tibetan region,as it is the highest and largest plateau in the world affecting global weather and climate systems.In this study,for the first time,we present CO_(2),CH_(4),and CO column measurements carried out by a Bruker EM27/SUN Fourier-transform infrared spectrometer(FTIR)at Golmud(36.42°E,94.91°N,2808 m)in August 2021.The mean and standard deviation of the column-average dry-air mixing ratio of CO_(2),CH_(4),and CO(XCO_(2),XCH_(4),and XCO)are 409.3±0.4 ppm,1905.5±19.4 ppb,and 103.1±7.7 ppb,respectively.The differences between the FTIR co-located TROPOMI/S5P satellite measurements at Golmud are 0.68±0.64%(13.1±12.2 ppb)for XCH_(4) and 9.81±3.48%(–10.7±3.8 ppb)for XCO,which are within their retrieval uncertainties.High correlations for both XCH_(4) and XCO are observed between the FTIR and S5P satellite measurements.Using the FLEXPART model and satellite measurements,we find that enhanced CH_(4) and CO columns in Golmud are affected by anthropogenic emissions transported from North India.This study provides an insight into the variations of the CO_(2),CH_(4),and CO columns in the Qinghai-Tibetan Plateau.展开更多
Endochondral ossification requires proper control of chondrocyte proliferation,differentiation,survival,and organization.Here we show that knockout ofα-parvin,an integrin-associated focal adhesion protein,from murine...Endochondral ossification requires proper control of chondrocyte proliferation,differentiation,survival,and organization.Here we show that knockout ofα-parvin,an integrin-associated focal adhesion protein,from murine limbs causes defects in endochondral ossification and dwarfism.The mutant long bones were shorter but wider,and the growth plates became disorganized,especially in the proliferative zone.With two-photon time-lapse imaging of bone explant culture,we provide direct evidence showing thatα-parvin regulates chondrocyte rotation,a process essential for chondrocytes to form columnar structure.Furthermore,loss ofα-parvin increased binucleation,elevated cell death,and caused dilation of the resting zones of mature growth plates.Single-cell RNA-seq analyses revealed alterations of transcriptome in all three zones(i.e.,resting,proliferative,and hypertrophic zones)of the growth plates.Our results demonstrate a crucial role ofα-parvin in long bone development and shed light on the cellular mechanism through whichα-parvin regulates the longitudinal growth of long bones.展开更多
Advanced gastric cancer is a common digestive system tumor,and its treatment has always been a difficult problem.In recent years,with the rapid development of immunotherapy,the treatment effect of advanced gastric can...Advanced gastric cancer is a common digestive system tumor,and its treatment has always been a difficult problem.In recent years,with the rapid development of immunotherapy,the treatment effect of advanced gastric cancer has been significantly improved.This article introduces the current status and clinical research progress of immune checkpoint inhibitors in advanced gastric cancer.Commonly used immunotherapy methods include chemical drug therapy,biological therapy,and gene therapy,among which the immune checkpoint inhibitors are currently one of the most popular immunotherapy methods,including nivolumab,pembrolizumab,and atezolizumab,which target programmed death ligand 1(PD-L1)low expression(1%–49%)and PD-L1 high expression(≥50%).The results of clinical studies have shown that immunotherapy can significantly prolong the survival of patients with advanced gastric cancer while having lower toxic side effects and better tolerance.However,immunotherapy also has some problems,such as drug resistance and repeated infection.Future research directions include exploring new immunotherapy methods,combination therapy,and individualized therapy.展开更多
It is of significance to design of stable and cost-effective electrocatalyst for water splitting with high efficiency in an alkaline medium.The major obstacles for practical application of water splitting devices are ...It is of significance to design of stable and cost-effective electrocatalyst for water splitting with high efficiency in an alkaline medium.The major obstacles for practical application of water splitting devices are lack of high-efficiency and low-cost electrocatalysts with low overpotential for both HER and OER.In this paper,we report a NiFe alloy decorated NiCoO2 hollow polyhedron(denoted as Ni Fe–Ni Co O2)by using[NiFe(CN)6]- intercalated NiCo–LDH as precursor.As evidenced by the electrochemical active surface area,the resultant Ni Fe–Ni Co O2 composite shows unique hollow nanostructure,which can not only provide abundant mass transport channels,but also increase the contact area of the NiFe–Ni Co O2 material with the electrolyte.The overpotential(η)demand is 286 mV for OER and 102 mV for HER at the current density of 10 mA/cm2 in an alkaline medium of 1 M KOH for the NiFe/NiCoO2 composite.This work provides a new pathway for preparation of the highly efficient bifunctional electrocatalysts for water splitting.展开更多
With Hemerocallis fulva‘Golden Doll'as an experimental material,the effects of different concentrations of neutral salt( NaCl) and alkaline salt( NaHCO3) stresses on photosynthesis and chlorophyll fluorescence ch...With Hemerocallis fulva‘Golden Doll'as an experimental material,the effects of different concentrations of neutral salt( NaCl) and alkaline salt( NaHCO3) stresses on photosynthesis and chlorophyll fluorescence characteristics in H. fulva seedlings were studied. The results showed that salt stress treatment significantly reduced the photosynthetic capacity of H. fulva. Under the NaCl and NaHCO3 stresses,the photosynthetic characteristics and chlorophyll fluorescence parameters of H. fulva seedlings were basically the same,but the photosynthetic characteristics and chlorophyll fluorescence parameter values of H. fulva seedlings were significantly different under different salt types and salt concentrations. With the extension of days of salt stress and the increase of salt concentration,the initial fluorescence yield( Fo) and non-photochemical quenching coefficient( NPQ) increased;the maximum fluorescence yield( Fm),maximum photochemical efficiency( Fv/Fm),PSII actual photosynthetic quantum yield( Y) and apparent quantum efficiency( AQY) all showed a downward trend;and moreover,with the extension of days of salt stress and the increase of salt concentration,the net photosynthetic rate( Pn) decreased and the intercellular CO2 concentration( Ci) increased. It was speculated that under salt stress,the photosynthetic characteristics of H. fulva leaves were inhibited. On the one hand,the non-stomatal limiting factor,i. e.,the chlorophyll content decreased,which led to the inhibition of photosynthetic characteristics. On the other hand,the decrease in the photosynthetic performance of mesophyll cells led to a decrease in the net photosynthetic rate of H. fulva. The changes of photosynthetic characteristics and chlorophyll fluorescence parameters in H. fulva caused by salt stress were closely related to the types of salts and salt concentration. High salt stress significantly inhibited the photosynthetic capacity of H. fulva‘Golden Doll',and the effect of NaHCO3 on H. fulva seedlings was significantly greater than that of NaCl.展开更多
In order to deal with aliasing distortions of Doppler frequencies shown in time-frequency representation（ TFR） with aspect undersampling,an approach using adaptive segmental compressive sampling according to the asp...In order to deal with aliasing distortions of Doppler frequencies shown in time-frequency representation（ TFR） with aspect undersampling,an approach using adaptive segmental compressive sampling according to the aspect dependencies of the scattering centers is proposed. The random noise problem induced by compressive sampling is solved by employing a series of signal processing techniques of filtering,image transformation and Hough Transform. Three examples are presented to verify the effectiveness of this approach. The comparisons between the built models and the precise scattered fields computed by a well-validated full-wave numerical method are investigated,and the results showgood agreements between each other.展开更多
Stress-induced cardiomyopathy,in contrast to acute myocardial infarction,is a type of acute heart failure characterized by reversible left ventricular dysfunction.Cardiac imaging primarily reveals left ventricle myoca...Stress-induced cardiomyopathy,in contrast to acute myocardial infarction,is a type of acute heart failure characterized by reversible left ventricular dysfunction.Cardiac imaging primarily reveals left ventricle myocardial stunning,81.7%of which is apical type.Emotional or psychological stress usually precedes the onset of stress-induced cardiomyopathy,which is increasingly being recognized as a unique neurogenic myocardial stunning disease.To distinguish between acute myocardial infarction and acute viral or auto-immune myocarditis,this review summarizes specific mechanisms of myocardial stunning in stress-induced cardiomyopathy,such as calcium disorders,metabolic alterations,anatomical and histological variations in different parts of the left ventricle,and microvascular dysfunction.展开更多
Objective: To evaluate the efficacy and safety of terazosin and plasma kinetic resection of the prostate (PKRP) in the treatment of benign prostatic hyperplasia (BPH) patients with coexisting hypertension. Methods: A ...Objective: To evaluate the efficacy and safety of terazosin and plasma kinetic resection of the prostate (PKRP) in the treatment of benign prostatic hyperplasia (BPH) patients with coexisting hypertension. Methods: A total of 205 men who suffered from BPH with concomitant hypertension were enrolled in this study. They all received PKRP surgery and terazosin medication from one week before to 3 months after the operation. The procedures of efficacy and safety were evaluated by analysis of the changes in blood pressures, IPSS, Qmax and the drug related adverse events 4 weeks and 3 months after the operation. Results: The systolic blood pressure decreased from 161 ± 12.33 mmHg at baseline to 148 ± 7.27 mmHg four weeks (P?P?P?P?P?P?展开更多
Internet brings us not only the convenience of communication but also some security risks,such as intercepting information and stealing information.Therefore,some important information needs to be hidden during commun...Internet brings us not only the convenience of communication but also some security risks,such as intercepting information and stealing information.Therefore,some important information needs to be hidden during communication.Steganography is the most common information hiding technology.This paper provides a literature review on digital image steganography.The existing steganography algorithms are classified into traditional algorithms and deep learning-based algorithms.Moreover,their advantages and weaknesses are pointed out.Finally,further research directions are discussed.展开更多
Saccharide sensing is a very meaningful research topic as saccharides are involved in many biological activities.However,it is challenging to design molecular sensors for saccharides because this family of compounds i...Saccharide sensing is a very meaningful research topic as saccharides are involved in many biological activities.However,it is challenging to design molecular sensors for saccharides because this family of compounds is hydromimetic in aqueous solutions and shares a similar chemical structure.In this review,research progress in the development of porphyrin-based saccharide sensors is described with representative examples.We focus on using porphyrin as the signal reporter because porphyrins exhibit unique advantages in high chemical stability,long emission wavelength,and multiple structural modification strategies.Reported literature results have been classified into mainly two sections according to the general working principles of the porphyrin sensor molecules.In the first section,recognition unit,design strategy and sensing performance of traditional porphyrin-based selective saccharide sensors are discussed.While in the second section,development of porphyrin-based sensor arrays for pattern recognition of saccharides has been summarized.Looking through the design strategy and sensing performance of reported achievements,it is reasonable to anticipate a bright future for designing practical porphyrin-based saccharide sensors.展开更多
For the treatment of MRSA-infected wounds,the spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs is a promising strategy.In this study,ROS-responsive HA-PBA/PVA(HPA)hydrogel was prepared...For the treatment of MRSA-infected wounds,the spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs is a promising strategy.In this study,ROS-responsive HA-PBA/PVA(HPA)hydrogel was prepared by phenylborate ester bond cross-linking between hyaluronic acid-grafted 3-amino phenylboronic acid(HA-PBA)and polyvinyl alcohol(PVA)to achieve spatiotemporally controlled release of two kinds of drug to treat MRSA-infected wound.The hydrophilic antibiotic moxifloxacin(M)was directly loaded in the hydrogel.And hydrophobic curcumin(Cur)with anti-inflammatory function was first mixed with Pluronic F127(PF)to form Cur-encapsulated PF micelles(Cur-PF),and then loaded into the HPA hydrogel.Due to the different hydrophilic and hydrophobic nature of moxifloxacin and Cur and their different existing forms in the HPA hydrogel,the final HPA/M&Cur-PF hydrogel can achieve different spatiotemporally sequential delivery of the two drugs.In addition,the swelling,degradation,self-healing,antibacterial,anti-inflammatory,antioxidant property,and biocompatibility of hydrogels were tested.Finally,in the MRSA-infected mouse skin wound,the hydrogel-treated group showed faster wound closure,less inflammation and more collagen deposition.Immunofluorescence experiments further confirmed that the hydrogel promoted better repair by reducing inflammation(TNF-a)and promoting vascular(VEGF)regeneration.In conclusion,this HPA/M&CurPF hydrogel that can spatiotemporally sequential deliver antibacterial and anti-inflammatory drugs showed great potential for the repair of MRSA-infected skin wounds.展开更多
Herein,we report the migratory hydroarylation of unactivated alkenes with aryl iodides using native and weakly coordinating amide directors under mild conditions.Synergistic coordination of the monodentate directing g...Herein,we report the migratory hydroarylation of unactivated alkenes with aryl iodides using native and weakly coordinating amide directors under mild conditions.Synergistic coordination of the monodentate directing group and the ligand enable the highly regioselective migratory hydroarylation via a chain walking process to form the thermodynamically stable five-membered nickelacyle intermediate.The protocol provides a variety of valuableα-aryl-substituted alkylamine products,and exhibited good functional group tolerance.The modification of bioactive compounds such as fenofibrate and indomethacin further highlights the synthetic value of this protocol.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51934003,52334004)Yunnan Major Scientific and Technological Projects(Grant No.202202AG050014)。
文摘To understand the strengths of rocks under complex stress states,a generalized nonlinear threedimensional(3D)Hoek‒Brown failure(NGHB)criterion was proposed in this study.This criterion shares the same parameters with the generalized HB(GHB)criterion and inherits the parameter advantages of GHB.Two new parameters,b,and n,were introduced into the NGHB criterion that primarily controls the deviatoric plane shape of the NGHB criterion under triaxial tension and compression,respectively.The NGHB criterion can consider the influence of intermediate principal stress(IPS),where the deviatoric plane shape satisfies the smoothness requirements,while the HB criterion not.This criterion can degenerate into the two modified 3D HB criteria,the Priest criterion under triaxial compression condition and the HB criterion under triaxial compression and tension condition.This criterion was verified using true triaxial test data for different parameters,six types of rocks,and two kinds of in situ rock masses.For comparison,three existing 3D HB criteria were selected for performance comparison research.The result showed that the NGHB criterion gave better prediction performance than other criteria.The prediction errors of the strength of six types of rocks and two kinds of in situ rock masses were in the range of 2.0724%-3.5091%and 1.0144%-3.2321%,respectively.The proposed criterion lays a preliminary theoretical foundation for prediction of engineering rock mass strength under complex in situ stress conditions.
基金This research was financially supported by the National Natural Science Foundation of China(Nos.51934003,52334004)Yunnan Innovation Team(No.202105AE 160023)+2 种基金Major Science and Technology Special Project of Yunnan Province,China(No.202102AF080001)Yunnan Major Scientific and Technological Projects,China(No.202202AG050014)Key Laboratory of Geohazard Forecast and Geoecological Restoration in Plateau Mountainous Area,MNR,and Yunnan Key Laboratory of Geohazard Forecast and Geoecological Restoration in Plateau Mountainous Area.
文摘Strength theory is the basic theory for calculating and designing the strength of engineering materials in civil,hydraulic,mechanical,aerospace,military,and other engineering disciplines.Therefore,the comprehensive study of the generalized nonlinear strength theory(GNST)of geomaterials has significance for the construction of engineering rock strength.This paper reviews the GNST of geomaterials to demonstrate the research status of nonlinear strength characteristics of geomaterials under complex stress paths.First,it systematically summarizes the research progress of GNST(classical and empirical criteria).Then,the latest research the authors conducted over the past five years on the GNST is introduced,and a generalized three-dimensional(3D)nonlinear Hoek‒Brown(HB)criterion(NGHB criterion)is proposed for practical applications.This criterion can be degenerated into the existing three modified HB criteria and has a better prediction performance.The strength prediction errors for six rocks and two in-situ rock masses are 2.0724%-3.5091%and 1.0144%-3.2321%,respectively.Finally,the development and outlook of the GNST are expounded,and a new topic about the building strength index of rock mass and determining the strength of in-situ engineering rock mass is proposed.The summarization of the GNST provides theoretical traceability and optimization for constructing in-situ engineering rock mass strength.
基金supported by the National Natural Science Foundation of China(Grant No.42205140,41975035)the National Key Research and Development Program of China(2021YFB3901000).
文摘Measurements of carbon dioxide(CO_(2)),methane(CH_(4)),and carbon monoxide(CO)are of great importance in the Qinghai-Tibetan region,as it is the highest and largest plateau in the world affecting global weather and climate systems.In this study,for the first time,we present CO_(2),CH_(4),and CO column measurements carried out by a Bruker EM27/SUN Fourier-transform infrared spectrometer(FTIR)at Golmud(36.42°E,94.91°N,2808 m)in August 2021.The mean and standard deviation of the column-average dry-air mixing ratio of CO_(2),CH_(4),and CO(XCO_(2),XCH_(4),and XCO)are 409.3±0.4 ppm,1905.5±19.4 ppb,and 103.1±7.7 ppb,respectively.The differences between the FTIR co-located TROPOMI/S5P satellite measurements at Golmud are 0.68±0.64%(13.1±12.2 ppb)for XCH_(4) and 9.81±3.48%(–10.7±3.8 ppb)for XCO,which are within their retrieval uncertainties.High correlations for both XCH_(4) and XCO are observed between the FTIR and S5P satellite measurements.Using the FLEXPART model and satellite measurements,we find that enhanced CH_(4) and CO columns in Golmud are affected by anthropogenic emissions transported from North India.This study provides an insight into the variations of the CO_(2),CH_(4),and CO columns in the Qinghai-Tibetan Plateau.
基金supported by the National Natural Science Foundation of China Grant 82273308,Inno HK@Health,Theme-based Research Scheme (Tl3-602/21-N)Guangdong-Dongguan Joint Research Scheme Guangdong-Hong Kong-Macao Program (2021B1515130004)+4 种基金the Natural Science Foundation of Guangdong Province Grant 2017B030301018the Special Support Program for Training High-Level Talents in Guangdong Grant 2019TQ05Y518the Shenzhen Innovation Committee of Science and Technology Grant JCYJ20220530112817040,ZDSYS20220606101604009the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital&Shenzhen Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Shenzhen E010122002supported by the Lombardi and Shinozuka Experimental Pathology Research Endowment Fund,University of Pittsburgh。
文摘Endochondral ossification requires proper control of chondrocyte proliferation,differentiation,survival,and organization.Here we show that knockout ofα-parvin,an integrin-associated focal adhesion protein,from murine limbs causes defects in endochondral ossification and dwarfism.The mutant long bones were shorter but wider,and the growth plates became disorganized,especially in the proliferative zone.With two-photon time-lapse imaging of bone explant culture,we provide direct evidence showing thatα-parvin regulates chondrocyte rotation,a process essential for chondrocytes to form columnar structure.Furthermore,loss ofα-parvin increased binucleation,elevated cell death,and caused dilation of the resting zones of mature growth plates.Single-cell RNA-seq analyses revealed alterations of transcriptome in all three zones(i.e.,resting,proliferative,and hypertrophic zones)of the growth plates.Our results demonstrate a crucial role ofα-parvin in long bone development and shed light on the cellular mechanism through whichα-parvin regulates the longitudinal growth of long bones.
文摘Advanced gastric cancer is a common digestive system tumor,and its treatment has always been a difficult problem.In recent years,with the rapid development of immunotherapy,the treatment effect of advanced gastric cancer has been significantly improved.This article introduces the current status and clinical research progress of immune checkpoint inhibitors in advanced gastric cancer.Commonly used immunotherapy methods include chemical drug therapy,biological therapy,and gene therapy,among which the immune checkpoint inhibitors are currently one of the most popular immunotherapy methods,including nivolumab,pembrolizumab,and atezolizumab,which target programmed death ligand 1(PD-L1)low expression(1%–49%)and PD-L1 high expression(≥50%).The results of clinical studies have shown that immunotherapy can significantly prolong the survival of patients with advanced gastric cancer while having lower toxic side effects and better tolerance.However,immunotherapy also has some problems,such as drug resistance and repeated infection.Future research directions include exploring new immunotherapy methods,combination therapy,and individualized therapy.
基金supported by the National Nature Science Foundation of China (U1707603, 21625101, 21521005, U1507102)the National Key Research and Development Program of China (2017YFB0307303)+2 种基金the 973 program (Grant No. 2014CB932104)Beijing Natural Science Foundation (2182047)the Fundamental Research Funds for the Central Universities (ZY1709)
文摘It is of significance to design of stable and cost-effective electrocatalyst for water splitting with high efficiency in an alkaline medium.The major obstacles for practical application of water splitting devices are lack of high-efficiency and low-cost electrocatalysts with low overpotential for both HER and OER.In this paper,we report a NiFe alloy decorated NiCoO2 hollow polyhedron(denoted as Ni Fe–Ni Co O2)by using[NiFe(CN)6]- intercalated NiCo–LDH as precursor.As evidenced by the electrochemical active surface area,the resultant Ni Fe–Ni Co O2 composite shows unique hollow nanostructure,which can not only provide abundant mass transport channels,but also increase the contact area of the NiFe–Ni Co O2 material with the electrolyte.The overpotential(η)demand is 286 mV for OER and 102 mV for HER at the current density of 10 mA/cm2 in an alkaline medium of 1 M KOH for the NiFe/NiCoO2 composite.This work provides a new pathway for preparation of the highly efficient bifunctional electrocatalysts for water splitting.
基金Supported by Science and Technology Research Project of Institutions of Higher Education in Hebei Province (BJ2017102)Tangshan Normal University Doctoral Fund (2014A06)。
文摘With Hemerocallis fulva‘Golden Doll'as an experimental material,the effects of different concentrations of neutral salt( NaCl) and alkaline salt( NaHCO3) stresses on photosynthesis and chlorophyll fluorescence characteristics in H. fulva seedlings were studied. The results showed that salt stress treatment significantly reduced the photosynthetic capacity of H. fulva. Under the NaCl and NaHCO3 stresses,the photosynthetic characteristics and chlorophyll fluorescence parameters of H. fulva seedlings were basically the same,but the photosynthetic characteristics and chlorophyll fluorescence parameter values of H. fulva seedlings were significantly different under different salt types and salt concentrations. With the extension of days of salt stress and the increase of salt concentration,the initial fluorescence yield( Fo) and non-photochemical quenching coefficient( NPQ) increased;the maximum fluorescence yield( Fm),maximum photochemical efficiency( Fv/Fm),PSII actual photosynthetic quantum yield( Y) and apparent quantum efficiency( AQY) all showed a downward trend;and moreover,with the extension of days of salt stress and the increase of salt concentration,the net photosynthetic rate( Pn) decreased and the intercellular CO2 concentration( Ci) increased. It was speculated that under salt stress,the photosynthetic characteristics of H. fulva leaves were inhibited. On the one hand,the non-stomatal limiting factor,i. e.,the chlorophyll content decreased,which led to the inhibition of photosynthetic characteristics. On the other hand,the decrease in the photosynthetic performance of mesophyll cells led to a decrease in the net photosynthetic rate of H. fulva. The changes of photosynthetic characteristics and chlorophyll fluorescence parameters in H. fulva caused by salt stress were closely related to the types of salts and salt concentration. High salt stress significantly inhibited the photosynthetic capacity of H. fulva‘Golden Doll',and the effect of NaHCO3 on H. fulva seedlings was significantly greater than that of NaCl.
基金Supported by the National Natural Science Foundation of China(61421001,61471041,61671059)
文摘In order to deal with aliasing distortions of Doppler frequencies shown in time-frequency representation（ TFR） with aspect undersampling,an approach using adaptive segmental compressive sampling according to the aspect dependencies of the scattering centers is proposed. The random noise problem induced by compressive sampling is solved by employing a series of signal processing techniques of filtering,image transformation and Hough Transform. Three examples are presented to verify the effectiveness of this approach. The comparisons between the built models and the precise scattered fields computed by a well-validated full-wave numerical method are investigated,and the results showgood agreements between each other.
基金supported primarily by the Distinguished Young Foundations of the First Affiliated Hospital of Harbin Medical University(HYD2020JQ002 to Dr Yin)The Science Foundation of the First Affiliated Hospital of Harbin Medical University(2018 L001 to Dr Yin).
文摘Stress-induced cardiomyopathy,in contrast to acute myocardial infarction,is a type of acute heart failure characterized by reversible left ventricular dysfunction.Cardiac imaging primarily reveals left ventricle myocardial stunning,81.7%of which is apical type.Emotional or psychological stress usually precedes the onset of stress-induced cardiomyopathy,which is increasingly being recognized as a unique neurogenic myocardial stunning disease.To distinguish between acute myocardial infarction and acute viral or auto-immune myocarditis,this review summarizes specific mechanisms of myocardial stunning in stress-induced cardiomyopathy,such as calcium disorders,metabolic alterations,anatomical and histological variations in different parts of the left ventricle,and microvascular dysfunction.
文摘Objective: To evaluate the efficacy and safety of terazosin and plasma kinetic resection of the prostate (PKRP) in the treatment of benign prostatic hyperplasia (BPH) patients with coexisting hypertension. Methods: A total of 205 men who suffered from BPH with concomitant hypertension were enrolled in this study. They all received PKRP surgery and terazosin medication from one week before to 3 months after the operation. The procedures of efficacy and safety were evaluated by analysis of the changes in blood pressures, IPSS, Qmax and the drug related adverse events 4 weeks and 3 months after the operation. Results: The systolic blood pressure decreased from 161 ± 12.33 mmHg at baseline to 148 ± 7.27 mmHg four weeks (P?P?P?P?P?P?
基金This work was supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China under Grant 17KJB520021,the PAPD fund,sponsored by Qing Lan Project.
文摘Internet brings us not only the convenience of communication but also some security risks,such as intercepting information and stealing information.Therefore,some important information needs to be hidden during communication.Steganography is the most common information hiding technology.This paper provides a literature review on digital image steganography.The existing steganography algorithms are classified into traditional algorithms and deep learning-based algorithms.Moreover,their advantages and weaknesses are pointed out.Finally,further research directions are discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.22278229,22131005 and 21904066)333 High Level Talent Project of Jiangsu Province.
文摘Saccharide sensing is a very meaningful research topic as saccharides are involved in many biological activities.However,it is challenging to design molecular sensors for saccharides because this family of compounds is hydromimetic in aqueous solutions and shares a similar chemical structure.In this review,research progress in the development of porphyrin-based saccharide sensors is described with representative examples.We focus on using porphyrin as the signal reporter because porphyrins exhibit unique advantages in high chemical stability,long emission wavelength,and multiple structural modification strategies.Reported literature results have been classified into mainly two sections according to the general working principles of the porphyrin sensor molecules.In the first section,recognition unit,design strategy and sensing performance of traditional porphyrin-based selective saccharide sensors are discussed.While in the second section,development of porphyrin-based sensor arrays for pattern recognition of saccharides has been summarized.Looking through the design strategy and sensing performance of reported achievements,it is reasonable to anticipate a bright future for designing practical porphyrin-based saccharide sensors.
基金supported by the National Natural Science Foundation of China(grant numbers 51973172,52273149)supported by 111 Project 2.0(grant number BPO618008)+2 种基金the Natural Science Foundation of Shaanxi Province(grant number 2020JC03)China Postdoctoral Science Foundation(grant number 2022M712498)State Key Laboratory for Mechanical Behavior of Materials,and the World-Class Universities(Disciplines)and the Characteristic Development Guidance Funds for the Central Universities.
文摘For the treatment of MRSA-infected wounds,the spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs is a promising strategy.In this study,ROS-responsive HA-PBA/PVA(HPA)hydrogel was prepared by phenylborate ester bond cross-linking between hyaluronic acid-grafted 3-amino phenylboronic acid(HA-PBA)and polyvinyl alcohol(PVA)to achieve spatiotemporally controlled release of two kinds of drug to treat MRSA-infected wound.The hydrophilic antibiotic moxifloxacin(M)was directly loaded in the hydrogel.And hydrophobic curcumin(Cur)with anti-inflammatory function was first mixed with Pluronic F127(PF)to form Cur-encapsulated PF micelles(Cur-PF),and then loaded into the HPA hydrogel.Due to the different hydrophilic and hydrophobic nature of moxifloxacin and Cur and their different existing forms in the HPA hydrogel,the final HPA/M&Cur-PF hydrogel can achieve different spatiotemporally sequential delivery of the two drugs.In addition,the swelling,degradation,self-healing,antibacterial,anti-inflammatory,antioxidant property,and biocompatibility of hydrogels were tested.Finally,in the MRSA-infected mouse skin wound,the hydrogel-treated group showed faster wound closure,less inflammation and more collagen deposition.Immunofluorescence experiments further confirmed that the hydrogel promoted better repair by reducing inflammation(TNF-a)and promoting vascular(VEGF)regeneration.In conclusion,this HPA/M&CurPF hydrogel that can spatiotemporally sequential deliver antibacterial and anti-inflammatory drugs showed great potential for the repair of MRSA-infected skin wounds.
基金supported by the National Natural Science Foundation of China(Nos.21901185 and 22301216)funds provided by Tianjin Normal University。
文摘Herein,we report the migratory hydroarylation of unactivated alkenes with aryl iodides using native and weakly coordinating amide directors under mild conditions.Synergistic coordination of the monodentate directing group and the ligand enable the highly regioselective migratory hydroarylation via a chain walking process to form the thermodynamically stable five-membered nickelacyle intermediate.The protocol provides a variety of valuableα-aryl-substituted alkylamine products,and exhibited good functional group tolerance.The modification of bioactive compounds such as fenofibrate and indomethacin further highlights the synthetic value of this protocol.
