This research investigates the ecological importance,changes,and status of mangrove wetlands along China’s coastline.Visual interpretation,geological surveys,and ISO clustering unsupervised classification methods are...This research investigates the ecological importance,changes,and status of mangrove wetlands along China’s coastline.Visual interpretation,geological surveys,and ISO clustering unsupervised classification methods are employed to interpret mangrove distribution from remote sensing images from 2021,utilizing ArcGIS software platform.Furthermore,the carbon storage capacity of mangrove wetlands is quantified using the carbon storage module of InVEST model.Results show that the mangrove wetlands in China covered an area of 278.85 km2 in 2021,predominantly distributed in Hainan,Guangxi,Guangdong,Fujian,Zhejiang,Taiwan,Hong Kong,and Macao.The total carbon storage is assessed at 2.11×10^(6) t,with specific regional data provided.Trends since the 1950s reveal periods of increase,decrease,sharp decrease,and slight-steady increases in mangrove areas in China.An important finding is the predominant replacement of natural coastlines adjacent to mangrove wetlands by artificial ones,highlighting the need for creating suitable spaces for mangrove restoration.This study is poised to guide future mangroverelated investigations and conservation strategies.展开更多
To tackle the problem of inaccurate short-term bus load prediction,especially during holidays,a Transformer-based scheme with tailored architectural enhancements is proposed.First,the input data are clustered to reduc...To tackle the problem of inaccurate short-term bus load prediction,especially during holidays,a Transformer-based scheme with tailored architectural enhancements is proposed.First,the input data are clustered to reduce complexity and capture inherent characteristics more effectively.Gated residual connections are then employed to selectively propagate salient features across layers,while an attention mechanism focuses on identifying prominent patterns in multivariate time-series data.Ultimately,a pre-trained structure is incorporated to reduce computational complexity.Experimental results based on extensive data show that the proposed scheme achieves improved prediction accuracy over comparative algorithms by at least 32.00%consistently across all buses evaluated,and the fitting effect of holiday load curves is outstanding.Meanwhile,the pre-trained structure drastically reduces the training time of the proposed algorithm by more than 65.75%.The proposed scheme can efficiently predict bus load results while enhancing robustness for holiday predictions,making it better adapted to real-world prediction scenarios.展开更多
Variations and trends in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, twelve indices of temperature extremes and 11 indices of p...Variations and trends in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, twelve indices of temperature extremes and 11 indices of precipita- tion extremes at 32 meteorological stations in Hengduan Mountains were examined for the period 1961-2008. The re- suits reveal statistically significant increases in the temperature of the warmest and coldest nights and in the frequen- cies of extreme warm days and nights. Decreases of the diurnal temperature range and the numbers of frost days and ice days are statistically significant. Regional averages of growing season length also display the trends consistent and significant with warming. At a large proportion of the stations, patterns of temperature extremes are consistent with warming since 1961： warming trends in minimum temperature indices are greater than those relating to maximum temperature. As the center of the Shaluli Mountain, the warming magnitudes decrease from inner to outer. Changes in precipitation extremes is low： trends are difficult to detect against the larger inter-annual and decadal-scale variability of precipitation, and only the wet day precipitation and the regional trend in consecutive dry days are significant at the 0.05 level. It can be concluded that the variation of extreme precipitation events is not obvious in the Hengduan Mountains, however, the regional trends generally decrease from the south to the north. Overall, the spatial distribution of temporal changes of all extreme climate indices in the Hengduan Mountains illustrated here reflects the climatic complexity in mountainous regions.展开更多
Previous studies have demonstrated that sevoflurane postconditioning can provide neuroprotection after hypoxic-ischemic injury and improve learning and memory function in developing rodent brains.The classical Rice-Va...Previous studies have demonstrated that sevoflurane postconditioning can provide neuroprotection after hypoxic-ischemic injury and improve learning and memory function in developing rodent brains.The classical Rice-Vannucci model was used to induce hypoxic-ischemic injury,and newborn(postnatal day 7)rats were treated with 2.4%sevoflurane for 30 minutes after hypoxic-ischemic injury.Our results showed that sevoflurane postconditioning significantly improved the learning and memory function of rats,decreased astrogliosis and glial scar formation,increased numbers of dendritic spines,and protected the histomorphology of the hippocampus.Mechanistically,sevoflurane postconditioning decreased expression of von Hippel-Lindau of hypoxia-inducible factor-1α and increased expression of DJ-1.Injection of 1.52μg of the hypoxia-inducible factor-1αinhibitor YC-1(Lificiguat)into the left lateral ventricle 30 minutes before hypoxic-ischemic injury reversed the neuroprotection induced by sevoflurane.This finding suggests that sevoflurane can effectively alleviate astrogliosis in the hippocampus and reduce learning and memory impairments caused by glial scar formation after hypoxic-ischemic injury.The underlying mechanism may be related to upregulated DJ-1 expression,reduced ubiquitination of hypoxia-inducible factor-1α,and stabilized hypoxiainducible factor-1αexpression.This study was approved by the Laboratory Animal Care Committee of China Medical University,China(approval No.2016PS337K)on November 9,2016.展开更多
An Al−3.6Cu−1Li alloy was subjected to room temperature rolling and cryorolling to investigate their effects on microstructure evolution and mechanical properties.The microstructure and aging characteristics of the ro...An Al−3.6Cu−1Li alloy was subjected to room temperature rolling and cryorolling to investigate their effects on microstructure evolution and mechanical properties.The microstructure and aging characteristics of the room temperature-rolled and the cryorolled alloys with 70%and 90%of thickness reductions were studied by microstructure analysis and mechanical tests.The samples subjected to cryorolling with 90%of thickness reduction have high strength and good toughness.This is mainly due to the inhibition of dynamic recovery and the accumulation of high-density dislocations in cryorolled samples.In addition,the artificial aging reveals that the temperature at which peak hardness is attained is inversely proportional to the deformation amount and directly proportional to the rolling temperature.Moreover,bright field images of cryorolled samples after aging indicate the existence of T1(Al2CuLi)precipitates.This suggests that the high stored strain energy enhances the aging kinetics of the alloy,which further promotes the nucleation of T1 phases.展开更多
Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic...Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic produces neurotoxicity by TRPVI.Methods:U87-MG cells were divided into control group,gene silencing group,empty vector group and TRPV gene up-rcgulation group.For cells in each group,flow cytometry was employed to detect the intracellular calcium ion concentration and mitochondrial membrane potential at different lime point from cellular perspective.Cell apoptosis of U87-MG was assayed by flow cytometry and MTT from a holistic perspective.Results:Calcium ion concentration increased along with time.The concentration in TRPV1 gene up-regulation group was significantly higher than those in other groups at each time point(P<0.05).After adding lidocaine.mitochondrial membrane potential in U87-MG significantly increased(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05).while in TRPV1 gene silencing group,the trend significantly decreased(P<0.05).Flow cytometry result and MTT result both showed that cell apoptosis in each group significantly increased after lidocaine was added(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05),while in TRPV1 gene silencing group,the trend significandy decreased(P<0.05).Moreover,apoptosis was more severe along with the increasing concentration of lidocaine(P<0.05).Conclusions:In this study,it was proved that lidocaine could dose-dependently induce the increase of intracellular calcium ion concentration,mitochondrial membrane potential and apoptosis in U87-MG glioma cell line.The up-regulation of TRPV1 enhanced cytotoxicity of lidocaine,which revealed the correlations between mem.Lidocaine might have increased intracellular calcium ion concentration by activating TRPVI gene and induced apoptosis of U87-GM glioma cell line by up-regulating mitochondrial membrane potential.展开更多
Ultrafine-grained(UFG)AA1060 sheets were fabricated via five-cycle accumulative roll bonding(ARB)and subsequent three-pass cold rolling(298 K),or cryorolling(83 K and 173 K).Microstructures of the aluminum samples wer...Ultrafine-grained(UFG)AA1060 sheets were fabricated via five-cycle accumulative roll bonding(ARB)and subsequent three-pass cold rolling(298 K),or cryorolling(83 K and 173 K).Microstructures of the aluminum samples were examined via transmission electron microscopy,and their mechanical properties were measured via tensile and microhardness testing.Results indicate that ultrafine grains in ARB-processed sheets were further refined by subsequent rolling,and the grain size became finer with reducing rolling temperature.The mean grain size of 666 nm in the sheets subjected to ARB was refined to 346 or 266 nm,respectively,via subsequent cold rolling or cryorolling(83 K).Subsequent cryorolling resulted in ultrafine-grained sheets of higher strength and ductility than those of the sheets subjected to cold rolling.展开更多
The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built i...The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.展开更多
BACKGROUND Solitary rectal ulcer syndrome(SRUS)is a rare rectal disorder characterized by bloody mucus in the stool,difficulty in defecation,pain,and anal swelling.To date,the etiology of this syndrome remains not wel...BACKGROUND Solitary rectal ulcer syndrome(SRUS)is a rare rectal disorder characterized by bloody mucus in the stool,difficulty in defecation,pain,and anal swelling.To date,the etiology of this syndrome remains not well understood and the diagnosis is frequently confused with other disorders,making treatment a clinical challenge.CASE SUMMARY A 50-year-old woman presented to our hospital with a 40-d history of bloody mucus in the stool and anal swelling.SRUS was suspected.Rectoscopy revealed a large,severe ulcerous lesion.Histologically,the lesion was characterized as chronic ulcer without clear tumor cells,and the final diagnosis of SRUS was made.The patient was treated with Chinese medicine therapy,with administration of Tong Xie Yao Fang.After 3 wk of treatment,the symptoms improved significantly.At 2-mo follow-up,rectoscopy in a local hospital showed healed ulcer scars without obvious protrusion 3 cm from the anal verge.CONCLUSION Chinese medicine therapy represents a potential treatment of SRUS with predominant rectal bleeding,mucinous discharge,and anal swelling pain.展开更多
The mechanical performances such as tensile strength and blast property of metal lined SiC/SiC composite cladding tubes were investigated. Nb or Ta was selected as liner material, and the SiC/SiC composite layer was f...The mechanical performances such as tensile strength and blast property of metal lined SiC/SiC composite cladding tubes were investigated. Nb or Ta was selected as liner material, and the SiC/SiC composite layer was fabricated by winding and different precursor impregnation and pyrolysis(PIP) processes. The tensile strengths of different tube samples were measured at room temperature(RT) and 1200 °C, respectively. The blast property was investigated through the maximum water pressure of tubes. And the fracture microstructures were observed by SEM.The highest tensile strength at RT was 150.7 MPa. The blast strength was enhanced with the PIP process increasing from 1 to 4 cycles and the tube of 4 PIP cycles had the highest water pressure of 34.7 MPa. Compared with the metal tubes, the multi-layer structure improved tensile and blast properties significantly. The different processes such as PIP cycles and pyrolytic carbon(PyC) coating were important factors to enhance the mechanical performances of SiC/SiC-based tubes. However, the retention rate of tensile strength was only 18.5% at 1200 °C.展开更多
In the present paper, chiral mesoporous silica nano-cocoon(A-CMSN) functionalized with amino group was synthesized, and its loading and release of indomethacin(IMC), a poorly soluble drug, was studied. Due to the use ...In the present paper, chiral mesoporous silica nano-cocoon(A-CMSN) functionalized with amino group was synthesized, and its loading and release of indomethacin(IMC), a poorly soluble drug, was studied. Due to the use of chiral anionic surfactants as a template, ACMSN possessed 2D hexagonal nano-cocoon morphology with curled channels on its surface, which was quite different from another 2D hexagonal mesoporous silica nanoparticles(MCM-41) with straightway channels. After being loaded into the two silica carriers by hydrogen bond, crystalline IMC converted to amorphous form, leading to the improved drug dissolution. And IMC loading capacity of A-CMSN was higher than MCM-41 because curled loading process originating from curvature chiral channels can hold more drug molecules. Compared with IMC, IMC loaded A-CMSN presented obviously fast release throughout the in vitro release experiment, while IMC loaded MCM-41 released faster than IMC at the initial 5 h then showed controlled slow release afterwards, which was closely related to the mesoporous silica nanoparticles and different channel mesostructures of these two carriers. A-CMSN possessed nano-cocoon morphology with curled 2D hexagonal channel and its channel length was shorter than MCM-41, therefore IMC molecules can easily get rid of the constraint of A-CMSN then to be surrounded by dissolution medium.展开更多
Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of ather...Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of atherosclerosis by increasing endothelial adhesiveness.Here,we sought to investigate whether CTRP1 also influences vascular dilatory functions.展开更多
The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effective...The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.展开更多
基金supported by China Geological Survey(DD20211301).
文摘This research investigates the ecological importance,changes,and status of mangrove wetlands along China’s coastline.Visual interpretation,geological surveys,and ISO clustering unsupervised classification methods are employed to interpret mangrove distribution from remote sensing images from 2021,utilizing ArcGIS software platform.Furthermore,the carbon storage capacity of mangrove wetlands is quantified using the carbon storage module of InVEST model.Results show that the mangrove wetlands in China covered an area of 278.85 km2 in 2021,predominantly distributed in Hainan,Guangxi,Guangdong,Fujian,Zhejiang,Taiwan,Hong Kong,and Macao.The total carbon storage is assessed at 2.11×10^(6) t,with specific regional data provided.Trends since the 1950s reveal periods of increase,decrease,sharp decrease,and slight-steady increases in mangrove areas in China.An important finding is the predominant replacement of natural coastlines adjacent to mangrove wetlands by artificial ones,highlighting the need for creating suitable spaces for mangrove restoration.This study is poised to guide future mangroverelated investigations and conservation strategies.
文摘To tackle the problem of inaccurate short-term bus load prediction,especially during holidays,a Transformer-based scheme with tailored architectural enhancements is proposed.First,the input data are clustered to reduce complexity and capture inherent characteristics more effectively.Gated residual connections are then employed to selectively propagate salient features across layers,while an attention mechanism focuses on identifying prominent patterns in multivariate time-series data.Ultimately,a pre-trained structure is incorporated to reduce computational complexity.Experimental results based on extensive data show that the proposed scheme achieves improved prediction accuracy over comparative algorithms by at least 32.00%consistently across all buses evaluated,and the fitting effect of holiday load curves is outstanding.Meanwhile,the pre-trained structure drastically reduces the training time of the proposed algorithm by more than 65.75%.The proposed scheme can efficiently predict bus load results while enhancing robustness for holiday predictions,making it better adapted to real-world prediction scenarios.
基金Under the auspices of West Light Foundation of Chinese Academy of Sciences (No. Y000141001)Key Program ofNational Natural Science Foundation of China (No. 91025002)+1 种基金Program for Incubation of Specialists in Glaciology and Geocryology of National Natural Science Foundation of China (No. 11J0930003)National Natural Science Foundation of China (No. 40725001,30970492)
文摘Variations and trends in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, twelve indices of temperature extremes and 11 indices of precipita- tion extremes at 32 meteorological stations in Hengduan Mountains were examined for the period 1961-2008. The re- suits reveal statistically significant increases in the temperature of the warmest and coldest nights and in the frequen- cies of extreme warm days and nights. Decreases of the diurnal temperature range and the numbers of frost days and ice days are statistically significant. Regional averages of growing season length also display the trends consistent and significant with warming. At a large proportion of the stations, patterns of temperature extremes are consistent with warming since 1961： warming trends in minimum temperature indices are greater than those relating to maximum temperature. As the center of the Shaluli Mountain, the warming magnitudes decrease from inner to outer. Changes in precipitation extremes is low： trends are difficult to detect against the larger inter-annual and decadal-scale variability of precipitation, and only the wet day precipitation and the regional trend in consecutive dry days are significant at the 0.05 level. It can be concluded that the variation of extreme precipitation events is not obvious in the Hengduan Mountains, however, the regional trends generally decrease from the south to the north. Overall, the spatial distribution of temporal changes of all extreme climate indices in the Hengduan Mountains illustrated here reflects the climatic complexity in mountainous regions.
基金supported by the National Nature Science Foundation of China,Nos.81671311,81870838the Key Research and Development Program of Liaoning Province of China,No.2018225004the Outstanding Scientific Fund of Shengjing Hospital of China,No.201708(all to PZ).
文摘Previous studies have demonstrated that sevoflurane postconditioning can provide neuroprotection after hypoxic-ischemic injury and improve learning and memory function in developing rodent brains.The classical Rice-Vannucci model was used to induce hypoxic-ischemic injury,and newborn(postnatal day 7)rats were treated with 2.4%sevoflurane for 30 minutes after hypoxic-ischemic injury.Our results showed that sevoflurane postconditioning significantly improved the learning and memory function of rats,decreased astrogliosis and glial scar formation,increased numbers of dendritic spines,and protected the histomorphology of the hippocampus.Mechanistically,sevoflurane postconditioning decreased expression of von Hippel-Lindau of hypoxia-inducible factor-1α and increased expression of DJ-1.Injection of 1.52μg of the hypoxia-inducible factor-1αinhibitor YC-1(Lificiguat)into the left lateral ventricle 30 minutes before hypoxic-ischemic injury reversed the neuroprotection induced by sevoflurane.This finding suggests that sevoflurane can effectively alleviate astrogliosis in the hippocampus and reduce learning and memory impairments caused by glial scar formation after hypoxic-ischemic injury.The underlying mechanism may be related to upregulated DJ-1 expression,reduced ubiquitination of hypoxia-inducible factor-1α,and stabilized hypoxiainducible factor-1αexpression.This study was approved by the Laboratory Animal Care Committee of China Medical University,China(approval No.2016PS337K)on November 9,2016.
基金Project(2019YFB2006500)supported by the National Key Research and Development Program of ChinaProject(51674303)supported by the National Natural Science Foundation of China+2 种基金Project(2018RS3015)supported by the Huxiang High-Level Talent Gathering Project of Hunan Province,ChinaProject(2019CX006)supported by the Innovation Driven Program of Central South University,ChinaProject supported by the Research Fund of the Key Laboratory of High Performance Complex Manufacturing at Central South University,China。
文摘An Al−3.6Cu−1Li alloy was subjected to room temperature rolling and cryorolling to investigate their effects on microstructure evolution and mechanical properties.The microstructure and aging characteristics of the room temperature-rolled and the cryorolled alloys with 70%and 90%of thickness reductions were studied by microstructure analysis and mechanical tests.The samples subjected to cryorolling with 90%of thickness reduction have high strength and good toughness.This is mainly due to the inhibition of dynamic recovery and the accumulation of high-density dislocations in cryorolled samples.In addition,the artificial aging reveals that the temperature at which peak hardness is attained is inversely proportional to the deformation amount and directly proportional to the rolling temperature.Moreover,bright field images of cryorolled samples after aging indicate the existence of T1(Al2CuLi)precipitates.This suggests that the high stored strain energy enhances the aging kinetics of the alloy,which further promotes the nucleation of T1 phases.
基金supported by the National Natural Science Foundation(NO.81260176)
文摘Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic produces neurotoxicity by TRPVI.Methods:U87-MG cells were divided into control group,gene silencing group,empty vector group and TRPV gene up-rcgulation group.For cells in each group,flow cytometry was employed to detect the intracellular calcium ion concentration and mitochondrial membrane potential at different lime point from cellular perspective.Cell apoptosis of U87-MG was assayed by flow cytometry and MTT from a holistic perspective.Results:Calcium ion concentration increased along with time.The concentration in TRPV1 gene up-regulation group was significantly higher than those in other groups at each time point(P<0.05).After adding lidocaine.mitochondrial membrane potential in U87-MG significantly increased(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05).while in TRPV1 gene silencing group,the trend significantly decreased(P<0.05).Flow cytometry result and MTT result both showed that cell apoptosis in each group significantly increased after lidocaine was added(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05),while in TRPV1 gene silencing group,the trend significandy decreased(P<0.05).Moreover,apoptosis was more severe along with the increasing concentration of lidocaine(P<0.05).Conclusions:In this study,it was proved that lidocaine could dose-dependently induce the increase of intracellular calcium ion concentration,mitochondrial membrane potential and apoptosis in U87-MG glioma cell line.The up-regulation of TRPV1 enhanced cytotoxicity of lidocaine,which revealed the correlations between mem.Lidocaine might have increased intracellular calcium ion concentration by activating TRPVI gene and induced apoptosis of U87-GM glioma cell line by up-regulating mitochondrial membrane potential.
基金financial supports from the National Key Research and Development Program of China (No. 2019YFB2006500)the National Natural Science Foundation of China (No. 51674303)+2 种基金the Huxiang High-level Talent Gathering Project of Hunan Province, China (No. 2018RS3015)the Innovation Driven Program of Central South University, China (No. 2019CX006)the Research Fund of the Key Laboratory of High Performance Complex Manufacturing at Central South University, China。
文摘Ultrafine-grained(UFG)AA1060 sheets were fabricated via five-cycle accumulative roll bonding(ARB)and subsequent three-pass cold rolling(298 K),or cryorolling(83 K and 173 K).Microstructures of the aluminum samples were examined via transmission electron microscopy,and their mechanical properties were measured via tensile and microhardness testing.Results indicate that ultrafine grains in ARB-processed sheets were further refined by subsequent rolling,and the grain size became finer with reducing rolling temperature.The mean grain size of 666 nm in the sheets subjected to ARB was refined to 346 or 266 nm,respectively,via subsequent cold rolling or cryorolling(83 K).Subsequent cryorolling resulted in ultrafine-grained sheets of higher strength and ductility than those of the sheets subjected to cold rolling.
基金financially supported by the National Key R&D Program of China(2018YFF0212503,2019YFF0216303,and 2016YFF0200502)the National Natural Science Foundation of China(21927812)the Research Project of the National Institute of Metrology(AKY1934)。
文摘The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance.In this study,a quadrupole-linear ion trap(Q-LIT)tandem mass spectrometer was designed and built in our laboratory.Target precursor ions were first selected in the quadrupole,and then injected,trapped,and fragmented simultaneously in the linear ion trap(LIT)to reduce the space charge effect,enrich the target product ions,and promote sensitivity.The targeted analytes were measured with selected reaction monitoring using a positive scan mode with electrospray ionization(ESI).Ions with a mass-to-charge ratio(m/z)ranging from 195 to 2022 were demonstrated.When scanning at 1218amu.s^(-1),unit resolution and an accuracy of higher than m/z 0.28 was obtained for m/z up to 2000.The dimensionless Mathieu parameter(q)value used in this study was 0.40 for collision-induced dissociation(CID),which was activated by resonance excitation.And an overall CID efficiency of 64%was achieved(activation time,50 ms).Guanidinoacetic acid(GAA)and creatine(CRE)were used as model compounds for small molecule clinical biomarkers.The limits of quantification were 1.0 and 0.2 nmol.L^(-1)for GAA and CRE,respectively.A total of 77 actual samples were successfully analyzed by the home-built ESI-Q-LIT tandem mass spectrometry system.The developed method can reduce matrix interference,minimize space charge effects,and avoid the chromatographic separation of complex samples to simplify the pretreatment process.This novel Q-LIT system is expected to be a good candidate for the determination of biomarkers in clinical diagnosis and therapeutics.
基金Supported by the Start-up Fund from Beijing University of Chinese Medicine,No.1000061020044
文摘BACKGROUND Solitary rectal ulcer syndrome(SRUS)is a rare rectal disorder characterized by bloody mucus in the stool,difficulty in defecation,pain,and anal swelling.To date,the etiology of this syndrome remains not well understood and the diagnosis is frequently confused with other disorders,making treatment a clinical challenge.CASE SUMMARY A 50-year-old woman presented to our hospital with a 40-d history of bloody mucus in the stool and anal swelling.SRUS was suspected.Rectoscopy revealed a large,severe ulcerous lesion.Histologically,the lesion was characterized as chronic ulcer without clear tumor cells,and the final diagnosis of SRUS was made.The patient was treated with Chinese medicine therapy,with administration of Tong Xie Yao Fang.After 3 wk of treatment,the symptoms improved significantly.At 2-mo follow-up,rectoscopy in a local hospital showed healed ulcer scars without obvious protrusion 3 cm from the anal verge.CONCLUSION Chinese medicine therapy represents a potential treatment of SRUS with predominant rectal bleeding,mucinous discharge,and anal swelling pain.
基金supported by the National Key R&D Program of China (No. 2018YFB1900603)the Natural Science Foundation of Hunan Province, China (No. 2020JJ4667)。
文摘The mechanical performances such as tensile strength and blast property of metal lined SiC/SiC composite cladding tubes were investigated. Nb or Ta was selected as liner material, and the SiC/SiC composite layer was fabricated by winding and different precursor impregnation and pyrolysis(PIP) processes. The tensile strengths of different tube samples were measured at room temperature(RT) and 1200 °C, respectively. The blast property was investigated through the maximum water pressure of tubes. And the fracture microstructures were observed by SEM.The highest tensile strength at RT was 150.7 MPa. The blast strength was enhanced with the PIP process increasing from 1 to 4 cycles and the tube of 4 PIP cycles had the highest water pressure of 34.7 MPa. Compared with the metal tubes, the multi-layer structure improved tensile and blast properties significantly. The different processes such as PIP cycles and pyrolytic carbon(PyC) coating were important factors to enhance the mechanical performances of SiC/SiC-based tubes. However, the retention rate of tensile strength was only 18.5% at 1200 °C.
基金supported by Postdoctoral Science Foundation of China 2017M611268
文摘In the present paper, chiral mesoporous silica nano-cocoon(A-CMSN) functionalized with amino group was synthesized, and its loading and release of indomethacin(IMC), a poorly soluble drug, was studied. Due to the use of chiral anionic surfactants as a template, ACMSN possessed 2D hexagonal nano-cocoon morphology with curled channels on its surface, which was quite different from another 2D hexagonal mesoporous silica nanoparticles(MCM-41) with straightway channels. After being loaded into the two silica carriers by hydrogen bond, crystalline IMC converted to amorphous form, leading to the improved drug dissolution. And IMC loading capacity of A-CMSN was higher than MCM-41 because curled loading process originating from curvature chiral channels can hold more drug molecules. Compared with IMC, IMC loaded A-CMSN presented obviously fast release throughout the in vitro release experiment, while IMC loaded MCM-41 released faster than IMC at the initial 5 h then showed controlled slow release afterwards, which was closely related to the mesoporous silica nanoparticles and different channel mesostructures of these two carriers. A-CMSN possessed nano-cocoon morphology with curled 2D hexagonal channel and its channel length was shorter than MCM-41, therefore IMC molecules can easily get rid of the constraint of A-CMSN then to be surrounded by dissolution medium.
文摘Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of atherosclerosis by increasing endothelial adhesiveness.Here,we sought to investigate whether CTRP1 also influences vascular dilatory functions.
基金the National Key R&D Program of China(2019YFD1101200,2019YFD1101204)Natural Science Foundation of China(51772150)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Provincial Key Research and Development Program(BE2018008-1).
文摘The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.
