Hepatocellular carcinoma(HCC)is a common malignancy that is driven by multiple genes and pathways.The aim of this study was to investigate the role and specific mechanism of the actin-interacting protein zyxin(ZYX)in ...Hepatocellular carcinoma(HCC)is a common malignancy that is driven by multiple genes and pathways.The aim of this study was to investigate the role and specific mechanism of the actin-interacting protein zyxin(ZYX)in HCC.We found that the expression of ZYX was significantly higher in HCC tissues compared to that in normal liver tissues.In addition,overexpression of ZYX in hepatoma cell lines(PLC/PRF/5,HCCLM3)enhanced their proliferation,migration and invasion,whereas ZYX knockdown had the opposite effects(SK HEP-1,Huh-7).Furthermore,the change in the expression levels of ZYX also altered that of proteins related to cell cycle,migration and invasion.Similar results were obtained with xenograft models.The AKT/mTOR signaling pathway is one of the key mediators of cancer development.While ZYX overexpression upregulated the levels of phosphorylated AKT/mTOR proteins,its knockdown had the opposite effect.In addition,the AKT inhibitor MK2206 neutralized the pro-oncogenic effects of ZYX on the HCC cells,whereas the AKT activator SC79 restored the proliferation,migration and invasion of HCC cells with ZYX knockdown.Taken together,ZYX promotes the malignant progression of HCC by activating AKT/mTOR signaling pathway,and is a potential therapeutic target in HCC.展开更多
The paper aimed to investigate the concentration variations and evaluate the bioaccumulation as well as the health risk of Cr, Ni, Cu, Zn, As, Cd and Pb in the aquaculture pond ecosystem during a complete breeding cyc...The paper aimed to investigate the concentration variations and evaluate the bioaccumulation as well as the health risk of Cr, Ni, Cu, Zn, As, Cd and Pb in the aquaculture pond ecosystem during a complete breeding cycle. The samples of water, sediment and aquatic organisms were collected from the pond of gull island in the Pearl River Delta, China. In the breeding cycle, the results revealed the metal concentration in the water increased, while the sediment metal concentration showed no significant difference. The heavy metal concentrations in the water were higher than the background values (December 2017) which related to the input of feeds. Sediment metal concentrations (Cr, Ni, Cu, Zn, As and Cd) in the sediment were higher than the background values of Guangdong Province, China, indicating these metal pollutions came from anthropogenic activities. While the concentration of Pb was comparable to the background value, implying that the Pb was mainly from the earth crust. In addition, various metals showed different affinity to fish organs (muscle, skin, bladder, gill, heart, kidney and liver). Zinc was abundant in skin, while As and Cd concentrations were highest in kidneys;Cu was accumulated highest in liver;Cr concentrations was highest in hearts;and Ni was mainly found in bladders, and the Pb was most commonly found in gills. The distribution of heavy metals in the tissues organs was in the sequence of: Zn > Cu > Cr > Ni > Pb > As > Cd. As the fish ages, the Cu and Zn concentration in tissue organs declined, while the Cr, Ni, As, Cd and Pb increased slightly. Estimations of health risks showed no evidence of potential threats to consumers.展开更多
Background and Objective Pulmonary hypertension (PH) is a fatal disease resulting from various causes. Studies from abroad have shown iron deficiency (ID) is closely associated with disease progression.This associatio...Background and Objective Pulmonary hypertension (PH) is a fatal disease resulting from various causes. Studies from abroad have shown iron deficiency (ID) is closely associated with disease progression.This association is common in pulmonary arterial hypertension (PAH)that belongs to World Health Organization group 1 PH. However, ID prevalence in Chinese patients suffering from PH is unclear so far.展开更多
In this work,the characterizations of Cu-SSZ-13 after hydrothermal aging(HTA)and thermal aging(TA)at different temperatures(750,800,and 850°C)are compared,and the differences between those two serious aged sample...In this work,the characterizations of Cu-SSZ-13 after hydrothermal aging(HTA)and thermal aging(TA)at different temperatures(750,800,and 850°C)are compared,and the differences between those two serious aged samples are analyzed.With this data,the effect of steam on catalysts deactivation during hydrothermal aging is analyzed.The TA at 750 and 800°C causes the dealumination and the agglomeration of Cu^(2+)ions to Cu O,resulting in the activity loss of Cu-SSZ-13.The presence of steam upon HTA at750 and 800°C aggravates the catalyst deactivation by increasing the Al detachment and the Cu^(2+)agglomeration.The structure and cupric state are almost the same in the Cu-SSZ-13 after TA and HTA at 850°C,respectively,indicating that the steam has little influence on the deactivation.The formation of CuAl_(2)O_(4) spinel is the primary reason for the deactivation after both HTA and TA at 850°C,probably attributed to the strong interaction between Cu^(2+)ions and framework Al sites at high temperatures.展开更多
This article gives an overview of the development and applications of the surfaceenhanced Raman scattering(SERS)techniques in biomedicine.We first introduce the fundamental principles of the SERS mechanisms.We also pr...This article gives an overview of the development and applications of the surfaceenhanced Raman scattering(SERS)techniques in biomedicine.We first introduce the fundamental principles of the SERS mechanisms.We also present the different fabrication techniques of SERS nanostructures and substrates.Finally,the importance and potential roles of the SERS nanostructures and substrates in biomedical applications are summarized.展开更多
Hafnium disulfide(HfS2) is a promising two-dimensional material for scaling electronic devices due to its higher carrier mobility, in which the combination of two-dimensional materials with traditional semiconductors ...Hafnium disulfide(HfS2) is a promising two-dimensional material for scaling electronic devices due to its higher carrier mobility, in which the combination of two-dimensional materials with traditional semiconductors in the framework of CMOS-compatible technology is necessary. We reported on the deposition of HfS2 nanocrystals by remote plasma enhanced atomic layer deposition at low temperature using Hf(N(CH3)(C2H5))4 and H2S as the reaction precursors. Selflimiting reaction behavior was observed at the deposition temperatures ranging from 150℃ to 350℃, and the film thickness increased linearly with the growth cycles. The uniform HfS2 nanocrystal thin films were obtained with the size of nanocrystal grain up to 27 nm. It was demonstrated that higher deposition temperature could enlarge the grain size and improve the HfS2 crystallinity, while causing crystallization of the mixed HfO2 above 450℃. These results suggested that atomic layer deposition is a low-temperature route to synthesize high quality HfS2 nanocrystals for electronic device or electrochemical applications.展开更多
A near-infrared germanium(Ge)Schottky photodetector(PD)with an ultrathin silicon(Si)barrier enhancement layer between the indium-doped tin oxide(ITO)electrode and Ge epilayer on Si or silicon-on-insulator(SOI)is propo...A near-infrared germanium(Ge)Schottky photodetector(PD)with an ultrathin silicon(Si)barrier enhancement layer between the indium-doped tin oxide(ITO)electrode and Ge epilayer on Si or silicon-on-insulator(SOI)is proposed and fabricated.The well-behaved ITO/Si cap/Ge Schottky junctions without intentional doping process for the Ge epilayer are formed on the Si and SOI substrates.The Si-and SOI-based ITO/Si cap/Ge Schottky PDs exhibit low dark current densities of 33 mA/cm2 and 44 mA/cm2,respectively.Benefited from the high transmissivity of ITO electrode and the reflectivity of SOI substrate,an optical responsivity of 0.19 A/W at 1550 nm wavelength is obtained for the SOI-based ITO/Si cap/Ge Schottky PD.These complementary metal–oxide–semiconductor(CMOS)compatible Si(or SOI)-based ITO/Si cap/Ge Schottky PDs are quite useful for detecting near-infrared wavelengths with high efficiency.展开更多
Objective: On the premise that the image quality meets the requirements of clinical diagnosis, we explored the methods to reduce the radiation dose of coronary artery imaging with Dual-Source CT (DSCT). Methods: We ra...Objective: On the premise that the image quality meets the requirements of clinical diagnosis, we explored the methods to reduce the radiation dose of coronary artery imaging with Dual-Source CT (DSCT). Methods: We randomly selected 200 patients with coronary heat disease (BIM 0.05). The average image noise in group A is (41.76 ± 7.98) HU, in group B the average image noise is (43.97 ± 3.88) HU, the dif- ference between the two groups was not statistically significant (P>0.05). The average CTDIvol of group A and B were (20.63 ± 2.24) mGy, (38.11 ± 10.69) mGy, respectively, then P <0.01. The average DLP of group A and B are (235.75 ± 28.64) mGycm and (492.59 ± 125.49) mGycm respectively, then P <0.01, the dif- ference of radiation dose had statistical significance (P<0.05). Conclusions: For coronary artery imaging with DSCT the heart electric pulse (AUTO) regulation technology can meet the diagnostic requirements and effectively reduce the radiation dose.展开更多
Heart murmur recognition and classification play an important role in the auscultative diagnosis. The method based on hidden markov model (HMM) was presented to recognize the heart murmur. The murmur was isolated on b...Heart murmur recognition and classification play an important role in the auscultative diagnosis. The method based on hidden markov model (HMM) was presented to recognize the heart murmur. The murmur was isolated on basis of the principle of wavelet analysis considering the time-frequency characteristics of the heart murmur. This method uses Mel frequency cepstral coefficient (MFCC) to extract representative features and develops hidden Markov model (HMM) for signal classification. The result shows that this method?is able to recognize the murmur efficiently and superior to BP?neural network (94.2% vs 82.8%). And the findings suggest that the method may have the potential to be used to assist doctors for a more objective diagnosis.展开更多
Objective: To investigate the correlation between radiation dose and radiation risk when patients are scanned by 64-slice spiral CT. Materials and Methods: SPSS 17.0 is used statistically for analyzing the patient’s ...Objective: To investigate the correlation between radiation dose and radiation risk when patients are scanned by 64-slice spiral CT. Materials and Methods: SPSS 17.0 is used statistically for analyzing the patient’s scanning parameters, radiation dose of monitoring and examining the patients who are scanning of their abdomen, chest and pelvic in our affiliated hospital. Results: SPSS statistical analysis shows that the factor related to radiation dose is scanning layer;the basic characteristics such as height and heart rate don’t affect the patient’s scan dose directly. Conclusion: Increasing the delay time after injection can reduce the scan numbers and monitoring layers of the machine, thus reduce the patient’s radiation dose and tube’s exposure time.展开更多
Objective: To observe the changes on skin wheal and erythema of skin prick test for the patients with allergic rhinitis during SLIT. Methods: Since March 2010 the 103 cases of SLIT attacked by allergic rhinitis patien...Objective: To observe the changes on skin wheal and erythema of skin prick test for the patients with allergic rhinitis during SLIT. Methods: Since March 2010 the 103 cases of SLIT attacked by allergic rhinitis patients, divided into four age groups, respectively measured the diameter of skin wheal and erythema before treatment, six months, one year and 2 years after SLIT. The data were analyzed by analysis of variance method;P Results: The results showed that the most changes of skin erythema diameter were statistically significant in N1, N2, N3 age group during test observation compare with the data before SLIT (p Conclusion: Although most of the skin test wheal did not change significantly during the treatment of SLIT, the erythema reaction decreased to a certain extent, indicating that the intensity of histamine release may be reduced during the treatment.展开更多
Passive vibration isolation systems have been widely applied due to their low power consumption and high reliability.Nevertheless,the design of vibration isolators is usually limited by the narrow space of installatio...Passive vibration isolation systems have been widely applied due to their low power consumption and high reliability.Nevertheless,the design of vibration isolators is usually limited by the narrow space of installation,and the requirement of heavy loads needs the high supporting stiffness that leads to the narrow isolation frequency band.To improve the vibration isolation performance of passive isolation systems for dynamic loaded equipment,a novel modular quasi-zero stiffness vibration isolator(MQZS-VI)with high linearity and integrated fluid damping is proposed.The MQZS-VI can achieve high-performance vibration isolation under a constraint mounted space,which is realized by highly integrating a novel combined magnetic negative stiffness mechanism into a damping structure:The stator magnets are integrated into the cylinder block,and the moving magnets providing negative-stiffness force also function as the piston supplying damping force simultaneously.An analytical model of the novel MQZS-VI is established and verified first.The effects of geometric parameters on the characteristics of negative stiffness and damping are then elucidated in detail based on the analytical model,and the design procedure is proposed to provide guidelines for the performance optimization of the MQZS-VI.Finally,static and dynamic experiments are conducted on the prototype.The experimental results demonstrate the proposed analytical model can be effectively utilized in the optimal design of the MQZS-VI,and the optimized MQZS-VI broadened greatly the isolation frequency band and suppressed the resonance peak simultaneously,which presented a substantial potential for application in vibration isolation for dynamic loaded equipment.展开更多
Al_(2)O_(3)-supported monometallic Ni,Co,and bimetallic Ni-Co nanocatalysts originated from layered double hydroxide precursors were synthesized by co-precipitation method,and used for the synthesis of useful 5-amino-...Al_(2)O_(3)-supported monometallic Ni,Co,and bimetallic Ni-Co nanocatalysts originated from layered double hydroxide precursors were synthesized by co-precipitation method,and used for the synthesis of useful 5-amino-1-pentanol(5-AP)and 1,5-pentanediol(1,5-PD)by reductive amination(RA)or direct hydrogenation of biofurfuralderived 2-hydroxytetrahydropyran(2-HTHP),respectively.In both reactions,the yield of the target products decreased monotonously with the increasing amounts of Co in the NiCo/Al_(2)O_(3)catalysts,owing probably to the replacement of highly reactive Ni by Co component with inferior hydrogenation activity at the low reaction temperature of 60℃.However,the incorporation of Co could improve the reducibility of the NiCo/Al_(2)O_(3)bimetallic catalysts and promote the reaction stability of the catalysts,especially for Ni_(2)Co1/Al_(2)O_(3),in both reactions with over 180 h time-on-stream.Characterization of the catalysts before and after the reaction showed that the incorporating Co could inhibit the sintering of metal particles and hinder the surface oxidation of the more reactive Ni0species,thanks to the formation of Ni-Co alloy in the bimetallic catalysts.DFT-based modeling of the reaction mechanisms is also performed,supporting the reaction pathway proposed previously and also the much higher activity of Ni in the RA of 2-HTHP as compared with Co.展开更多
The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots...The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots of challenges.Herein,natural attapulgite(ATP)was applied as support for the fabrication of active Ni catalysts with different Ni loadings(5–30 wt%)by the deposition-precipitation method.The Ni/ATP-550 catalyst with 10–15 wt%Ni loadings was found to present the highest catalytic performance for the synthesis of valuable 5-amino-1-pentanol(5-AP)via reductive amination of biofurfural-derived 2-hydroxytetrahydropyran among a variety of commonly used oxide supports loaded Ni catalysts,as well as ATP supported nickel catalysts with other loadings,achieving 5-AP yield up to 94%.The intrinsic activity of the Ni/ATP catalysts was found to depend strongly on the Ni^(0) crystallite size and Ni^(0) fraction of the catalysts,which generally increased with increasing Ni^(0) crystallite size and fraction,owing probably to the hydrogenation of imine intermediate is a structure-sensitive reaction.The efficient 10Ni/ATP-550 catalyst also exhibited good activity and stability in the reductive amination of several other biomass-derived aldehydes and ketones to their corresponding primary amines with good to excellent yields(81%–99%).This work provided a clean and efficient natural ATP-supported non-noble metal nickel-based catalytic system for the reductive amination of aldehydes and ketones to synthesize high-value-added primary amines,which could be a promising candidate for the industrial production of amines.展开更多
The global Coronavirus disease 2019(COVID-19)pandemic caused by SARS-CoV-2 has affected more than eight million people.There is an urgent need to investigate how the adaptive immunity is established in COVID-19 patien...The global Coronavirus disease 2019(COVID-19)pandemic caused by SARS-CoV-2 has affected more than eight million people.There is an urgent need to investigate how the adaptive immunity is established in COVID-19 patients.In this study,we proled adaptive immune cells of PBMCs from recovered COVID-19 patients with varying disease severity using single-cell RNA and TCR/BCR V(D)J sequencing.The sequencing data revealed SARS-CoV-2-specic shufing of adaptive immune repertories and COVID-19-induced remodeling of peripheral lymphocytes.Characterization of variations in the peripheral T and B cells from the COVID-19 patients revealed a positive correlation of humoral immune response and T-cell immune memory with disease severity.Sequencing and functional data revealed SARS-CoV-2-specic T-cell immune memory in the convalescent COVID-19 patients.Furthermore,we also identied novel antigens that are responsive in the convalescent patients.Altogether,our study reveals adaptive immune repertories underlying pathogenesis and recovery in severe versus mild COVID-19 patients,providing valuable information for potential vaccine and therapeutic development against SARS-CoV-2 infection.展开更多
Although solid-phase extraction is a useful approach for metal ion separation from aqueous solutions,existing sorbents suffer from low extraction effici-encies and/or instability when in contact with strong acidic med...Although solid-phase extraction is a useful approach for metal ion separation from aqueous solutions,existing sorbents suffer from low extraction effici-encies and/or instability when in contact with strong acidic media.We report here the first study on rational design and fabrication of phosphonate-decorated covalent organic frameworks,COF-IHEP1 and COF-IHEP2,for efficient and selective extraction of of uranium(VI)[U(VI)]and plutonium(IV)[Pu(IV)]from highly acidic solutions.展开更多
基金supported by the National Natural Science Foundation of China(No.82170587)the National Natural Science Foundation of China(No.82100647)+3 种基金Luzhou Municipal People’s Government-Southwest Medical University Science and Technology Strategic Cooperation Project(No.2021LZXNYD-Z01)Sichuan Province International Science and Technology Innovation Cooperation Project(No.2023YFH0078)Sichuan Science and Technology Program(2022YFS0625)the Talent Development Project of the Affiliated Hospital of Southwest Medical University.
文摘Hepatocellular carcinoma(HCC)is a common malignancy that is driven by multiple genes and pathways.The aim of this study was to investigate the role and specific mechanism of the actin-interacting protein zyxin(ZYX)in HCC.We found that the expression of ZYX was significantly higher in HCC tissues compared to that in normal liver tissues.In addition,overexpression of ZYX in hepatoma cell lines(PLC/PRF/5,HCCLM3)enhanced their proliferation,migration and invasion,whereas ZYX knockdown had the opposite effects(SK HEP-1,Huh-7).Furthermore,the change in the expression levels of ZYX also altered that of proteins related to cell cycle,migration and invasion.Similar results were obtained with xenograft models.The AKT/mTOR signaling pathway is one of the key mediators of cancer development.While ZYX overexpression upregulated the levels of phosphorylated AKT/mTOR proteins,its knockdown had the opposite effect.In addition,the AKT inhibitor MK2206 neutralized the pro-oncogenic effects of ZYX on the HCC cells,whereas the AKT activator SC79 restored the proliferation,migration and invasion of HCC cells with ZYX knockdown.Taken together,ZYX promotes the malignant progression of HCC by activating AKT/mTOR signaling pathway,and is a potential therapeutic target in HCC.
文摘The paper aimed to investigate the concentration variations and evaluate the bioaccumulation as well as the health risk of Cr, Ni, Cu, Zn, As, Cd and Pb in the aquaculture pond ecosystem during a complete breeding cycle. The samples of water, sediment and aquatic organisms were collected from the pond of gull island in the Pearl River Delta, China. In the breeding cycle, the results revealed the metal concentration in the water increased, while the sediment metal concentration showed no significant difference. The heavy metal concentrations in the water were higher than the background values (December 2017) which related to the input of feeds. Sediment metal concentrations (Cr, Ni, Cu, Zn, As and Cd) in the sediment were higher than the background values of Guangdong Province, China, indicating these metal pollutions came from anthropogenic activities. While the concentration of Pb was comparable to the background value, implying that the Pb was mainly from the earth crust. In addition, various metals showed different affinity to fish organs (muscle, skin, bladder, gill, heart, kidney and liver). Zinc was abundant in skin, while As and Cd concentrations were highest in kidneys;Cu was accumulated highest in liver;Cr concentrations was highest in hearts;and Ni was mainly found in bladders, and the Pb was most commonly found in gills. The distribution of heavy metals in the tissues organs was in the sequence of: Zn > Cu > Cr > Ni > Pb > As > Cd. As the fish ages, the Cu and Zn concentration in tissue organs declined, while the Cr, Ni, As, Cd and Pb increased slightly. Estimations of health risks showed no evidence of potential threats to consumers.
文摘Background and Objective Pulmonary hypertension (PH) is a fatal disease resulting from various causes. Studies from abroad have shown iron deficiency (ID) is closely associated with disease progression.This association is common in pulmonary arterial hypertension (PAH)that belongs to World Health Organization group 1 PH. However, ID prevalence in Chinese patients suffering from PH is unclear so far.
基金supported by the National Key Research and Development Program of China (2018YFC0214103)the National Natural Science Foundation of China (22006044)the Scientific Research Funds of Huaqiao University (605-50Y200270001)。
文摘In this work,the characterizations of Cu-SSZ-13 after hydrothermal aging(HTA)and thermal aging(TA)at different temperatures(750,800,and 850°C)are compared,and the differences between those two serious aged samples are analyzed.With this data,the effect of steam on catalysts deactivation during hydrothermal aging is analyzed.The TA at 750 and 800°C causes the dealumination and the agglomeration of Cu^(2+)ions to Cu O,resulting in the activity loss of Cu-SSZ-13.The presence of steam upon HTA at750 and 800°C aggravates the catalyst deactivation by increasing the Al detachment and the Cu^(2+)agglomeration.The structure and cupric state are almost the same in the Cu-SSZ-13 after TA and HTA at 850°C,respectively,indicating that the steam has little influence on the deactivation.The formation of CuAl_(2)O_(4) spinel is the primary reason for the deactivation after both HTA and TA at 850°C,probably attributed to the strong interaction between Cu^(2+)ions and framework Al sites at high temperatures.
基金supported by the Academic Research Fund from the Ministry of Education,the Biomedical Research Council,the National Medical Research Council,and the Faculty Research Fund from the National University of Singapore.
文摘This article gives an overview of the development and applications of the surfaceenhanced Raman scattering(SERS)techniques in biomedicine.We first introduce the fundamental principles of the SERS mechanisms.We also present the different fabrication techniques of SERS nanostructures and substrates.Finally,the importance and potential roles of the SERS nanostructures and substrates in biomedical applications are summarized.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFB2200103)。
文摘Hafnium disulfide(HfS2) is a promising two-dimensional material for scaling electronic devices due to its higher carrier mobility, in which the combination of two-dimensional materials with traditional semiconductors in the framework of CMOS-compatible technology is necessary. We reported on the deposition of HfS2 nanocrystals by remote plasma enhanced atomic layer deposition at low temperature using Hf(N(CH3)(C2H5))4 and H2S as the reaction precursors. Selflimiting reaction behavior was observed at the deposition temperatures ranging from 150℃ to 350℃, and the film thickness increased linearly with the growth cycles. The uniform HfS2 nanocrystal thin films were obtained with the size of nanocrystal grain up to 27 nm. It was demonstrated that higher deposition temperature could enlarge the grain size and improve the HfS2 crystallinity, while causing crystallization of the mixed HfO2 above 450℃. These results suggested that atomic layer deposition is a low-temperature route to synthesize high quality HfS2 nanocrystals for electronic device or electrochemical applications.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFB2200103)the National Natural Science Foundation of China(Grant No.61474094)Principal Fund of Minnan Normal University(Grant No.KJ2020006).
文摘A near-infrared germanium(Ge)Schottky photodetector(PD)with an ultrathin silicon(Si)barrier enhancement layer between the indium-doped tin oxide(ITO)electrode and Ge epilayer on Si or silicon-on-insulator(SOI)is proposed and fabricated.The well-behaved ITO/Si cap/Ge Schottky junctions without intentional doping process for the Ge epilayer are formed on the Si and SOI substrates.The Si-and SOI-based ITO/Si cap/Ge Schottky PDs exhibit low dark current densities of 33 mA/cm2 and 44 mA/cm2,respectively.Benefited from the high transmissivity of ITO electrode and the reflectivity of SOI substrate,an optical responsivity of 0.19 A/W at 1550 nm wavelength is obtained for the SOI-based ITO/Si cap/Ge Schottky PD.These complementary metal–oxide–semiconductor(CMOS)compatible Si(or SOI)-based ITO/Si cap/Ge Schottky PDs are quite useful for detecting near-infrared wavelengths with high efficiency.
文摘Objective: On the premise that the image quality meets the requirements of clinical diagnosis, we explored the methods to reduce the radiation dose of coronary artery imaging with Dual-Source CT (DSCT). Methods: We randomly selected 200 patients with coronary heat disease (BIM 0.05). The average image noise in group A is (41.76 ± 7.98) HU, in group B the average image noise is (43.97 ± 3.88) HU, the dif- ference between the two groups was not statistically significant (P>0.05). The average CTDIvol of group A and B were (20.63 ± 2.24) mGy, (38.11 ± 10.69) mGy, respectively, then P <0.01. The average DLP of group A and B are (235.75 ± 28.64) mGycm and (492.59 ± 125.49) mGycm respectively, then P <0.01, the dif- ference of radiation dose had statistical significance (P<0.05). Conclusions: For coronary artery imaging with DSCT the heart electric pulse (AUTO) regulation technology can meet the diagnostic requirements and effectively reduce the radiation dose.
文摘Heart murmur recognition and classification play an important role in the auscultative diagnosis. The method based on hidden markov model (HMM) was presented to recognize the heart murmur. The murmur was isolated on basis of the principle of wavelet analysis considering the time-frequency characteristics of the heart murmur. This method uses Mel frequency cepstral coefficient (MFCC) to extract representative features and develops hidden Markov model (HMM) for signal classification. The result shows that this method?is able to recognize the murmur efficiently and superior to BP?neural network (94.2% vs 82.8%). And the findings suggest that the method may have the potential to be used to assist doctors for a more objective diagnosis.
文摘Objective: To investigate the correlation between radiation dose and radiation risk when patients are scanned by 64-slice spiral CT. Materials and Methods: SPSS 17.0 is used statistically for analyzing the patient’s scanning parameters, radiation dose of monitoring and examining the patients who are scanning of their abdomen, chest and pelvic in our affiliated hospital. Results: SPSS statistical analysis shows that the factor related to radiation dose is scanning layer;the basic characteristics such as height and heart rate don’t affect the patient’s scan dose directly. Conclusion: Increasing the delay time after injection can reduce the scan numbers and monitoring layers of the machine, thus reduce the patient’s radiation dose and tube’s exposure time.
文摘Objective: To observe the changes on skin wheal and erythema of skin prick test for the patients with allergic rhinitis during SLIT. Methods: Since March 2010 the 103 cases of SLIT attacked by allergic rhinitis patients, divided into four age groups, respectively measured the diameter of skin wheal and erythema before treatment, six months, one year and 2 years after SLIT. The data were analyzed by analysis of variance method;P Results: The results showed that the most changes of skin erythema diameter were statistically significant in N1, N2, N3 age group during test observation compare with the data before SLIT (p Conclusion: Although most of the skin test wheal did not change significantly during the treatment of SLIT, the erythema reaction decreased to a certain extent, indicating that the intensity of histamine release may be reduced during the treatment.
基金supported by the National Key R&D Program of China(Grant Nos.2020YFB2007300 and 2020YFB2007601)the National Natural Science Foundation of China(Grant Nos.52075193,52305107,and 52275112)+1 种基金the National Science and Technology Major Project of China(Grant No.2017ZX02101007-002)the Postdoctoral Science Foundation of China(Grant No.2022M711250).
文摘Passive vibration isolation systems have been widely applied due to their low power consumption and high reliability.Nevertheless,the design of vibration isolators is usually limited by the narrow space of installation,and the requirement of heavy loads needs the high supporting stiffness that leads to the narrow isolation frequency band.To improve the vibration isolation performance of passive isolation systems for dynamic loaded equipment,a novel modular quasi-zero stiffness vibration isolator(MQZS-VI)with high linearity and integrated fluid damping is proposed.The MQZS-VI can achieve high-performance vibration isolation under a constraint mounted space,which is realized by highly integrating a novel combined magnetic negative stiffness mechanism into a damping structure:The stator magnets are integrated into the cylinder block,and the moving magnets providing negative-stiffness force also function as the piston supplying damping force simultaneously.An analytical model of the novel MQZS-VI is established and verified first.The effects of geometric parameters on the characteristics of negative stiffness and damping are then elucidated in detail based on the analytical model,and the design procedure is proposed to provide guidelines for the performance optimization of the MQZS-VI.Finally,static and dynamic experiments are conducted on the prototype.The experimental results demonstrate the proposed analytical model can be effectively utilized in the optimal design of the MQZS-VI,and the optimized MQZS-VI broadened greatly the isolation frequency band and suppressed the resonance peak simultaneously,which presented a substantial potential for application in vibration isolation for dynamic loaded equipment.
基金financially supported by the National Natural Science Foundation of China(21872155,22102198,and 22272187)the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences(XDA21010700)the CAS"Light of West China"Program
文摘Al_(2)O_(3)-supported monometallic Ni,Co,and bimetallic Ni-Co nanocatalysts originated from layered double hydroxide precursors were synthesized by co-precipitation method,and used for the synthesis of useful 5-amino-1-pentanol(5-AP)and 1,5-pentanediol(1,5-PD)by reductive amination(RA)or direct hydrogenation of biofurfuralderived 2-hydroxytetrahydropyran(2-HTHP),respectively.In both reactions,the yield of the target products decreased monotonously with the increasing amounts of Co in the NiCo/Al_(2)O_(3)catalysts,owing probably to the replacement of highly reactive Ni by Co component with inferior hydrogenation activity at the low reaction temperature of 60℃.However,the incorporation of Co could improve the reducibility of the NiCo/Al_(2)O_(3)bimetallic catalysts and promote the reaction stability of the catalysts,especially for Ni_(2)Co1/Al_(2)O_(3),in both reactions with over 180 h time-on-stream.Characterization of the catalysts before and after the reaction showed that the incorporating Co could inhibit the sintering of metal particles and hinder the surface oxidation of the more reactive Ni0species,thanks to the formation of Ni-Co alloy in the bimetallic catalysts.DFT-based modeling of the reaction mechanisms is also performed,supporting the reaction pathway proposed previously and also the much higher activity of Ni in the RA of 2-HTHP as compared with Co.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21872155 and 22102198)the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences(No.XDA21010700)the Western Young Scholar Program of the Chinese Academy of Sciences and the Open Project of Key Laboratory of Clay Mineral Applied Research of Gansu Province.
文摘The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots of challenges.Herein,natural attapulgite(ATP)was applied as support for the fabrication of active Ni catalysts with different Ni loadings(5–30 wt%)by the deposition-precipitation method.The Ni/ATP-550 catalyst with 10–15 wt%Ni loadings was found to present the highest catalytic performance for the synthesis of valuable 5-amino-1-pentanol(5-AP)via reductive amination of biofurfural-derived 2-hydroxytetrahydropyran among a variety of commonly used oxide supports loaded Ni catalysts,as well as ATP supported nickel catalysts with other loadings,achieving 5-AP yield up to 94%.The intrinsic activity of the Ni/ATP catalysts was found to depend strongly on the Ni^(0) crystallite size and Ni^(0) fraction of the catalysts,which generally increased with increasing Ni^(0) crystallite size and fraction,owing probably to the hydrogenation of imine intermediate is a structure-sensitive reaction.The efficient 10Ni/ATP-550 catalyst also exhibited good activity and stability in the reductive amination of several other biomass-derived aldehydes and ketones to their corresponding primary amines with good to excellent yields(81%–99%).This work provided a clean and efficient natural ATP-supported non-noble metal nickel-based catalytic system for the reductive amination of aldehydes and ketones to synthesize high-value-added primary amines,which could be a promising candidate for the industrial production of amines.
基金supported by the National Key Research and Development Program of China(2018YFA0702100 and 2018YFB0703600)the National Natural Science Foundation of China(51772012 and 51632005)+5 种基金Shenzhen Peacock Plan team(KQTD2016022619565991)Beijing Natural Science Foundation(JQ18004)China Postdoctoral Science Foundation Grant(2019M650429)111 Project(B17002)the National Science Foundation for Distinguished Young Scholars(51925101)the financial support from Singapore Ministry of Education Tier 1grant(R-284-000-212-114)for Lee Kuan Yew Postdoctoral Fellowship。
基金funded by the National Natural Science Foundation of China grant no.31825008 and 31422014 to Z.H.and grant no.61872117 to F.Z.
文摘The global Coronavirus disease 2019(COVID-19)pandemic caused by SARS-CoV-2 has affected more than eight million people.There is an urgent need to investigate how the adaptive immunity is established in COVID-19 patients.In this study,we proled adaptive immune cells of PBMCs from recovered COVID-19 patients with varying disease severity using single-cell RNA and TCR/BCR V(D)J sequencing.The sequencing data revealed SARS-CoV-2-specic shufing of adaptive immune repertories and COVID-19-induced remodeling of peripheral lymphocytes.Characterization of variations in the peripheral T and B cells from the COVID-19 patients revealed a positive correlation of humoral immune response and T-cell immune memory with disease severity.Sequencing and functional data revealed SARS-CoV-2-specic T-cell immune memory in the convalescent COVID-19 patients.Furthermore,we also identied novel antigens that are responsive in the convalescent patients.Altogether,our study reveals adaptive immune repertories underlying pathogenesis and recovery in severe versus mild COVID-19 patients,providing valuable information for potential vaccine and therapeutic development against SARS-CoV-2 infection.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.21577144,21777161,11575212,and 21806167)the Science Challenge Project(TZ2016004)the Youth Innovation Promotion As-sociation of CAS(2017020).
文摘Although solid-phase extraction is a useful approach for metal ion separation from aqueous solutions,existing sorbents suffer from low extraction effici-encies and/or instability when in contact with strong acidic media.We report here the first study on rational design and fabrication of phosphonate-decorated covalent organic frameworks,COF-IHEP1 and COF-IHEP2,for efficient and selective extraction of of uranium(VI)[U(VI)]and plutonium(IV)[Pu(IV)]from highly acidic solutions.