After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve we...After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve weather observations,quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction(NWP) models.In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation.展开更多
Background: Intraductal administration of cytotoxic agents has been shown to inhibit the development of breast cancer in animal models. The object of this study was to demonstrate the safety of intraductal delivery c...Background: Intraductal administration of cytotoxic agents has been shown to inhibit the development of breast cancer in animal models. The object of this study was to demonstrate the safety of intraductal delivery cytotoxic agents in patients prior to mastectomy. This method is hopeful to be developed as a chemoprevention approach in patients with pre-malignant or non-invasive ductal lesions to prevent breast cancer which will be further developed.Methods: Two drugs, pegylated liposomal doxorubicin(PLD) and carboplatin were administered at three dose levels(PLD: 10, 20, 50 mg and carboplatin 60, 120, 300 mg). There were five subjects in each group with 15 subjects treated with each drug once. Venous blood samples were obtained for pharmacokinetic analysis. The breast was removed surgically 2-5 days post administration and the treated ducts were marked to enable identification on pathological evaluation. Results: Intraductal administration was generally well-tolerated with mild, transient breast discomfort. In the carboplatin arm, three women at the 300 mg dose experienced mild nausea and vomiting. In the PLD arm most women had mild erythema and swelling of the breast over the 72 hours following the drug administration. Patients receiving the 50 mg dose experienced local erythema until the time of surgery. Pharmacokinetic analysis showed that carboplatin rapidly entered systemic circulation with an early peak time(T max -30 min) with a corresponding plasma ultrafiltrate area under the curve(AUC) consistent with the Calvert Formula using estimated glomerular filtration rate(GFR). Total plasma doxorubicin had delayed peak concentration times(T max 48 hours) with a linear dose response and peak concentrations substantially lower than expected from equivalent intravenous injection dosing. No doxorubicinol metabolite was detected in the plasma. Conclusions: This study demonstrates that cytotoxic drugs can be safely administered into breast ducts with minimal toxicity.展开更多
Objective: In patients with chemotherapy-induced amenorrhea (CIA), the menopausal status is ambiguous anddifficult to evaluate. This study aimed to establish a discriminative model to predict and classify the menop...Objective: In patients with chemotherapy-induced amenorrhea (CIA), the menopausal status is ambiguous anddifficult to evaluate. This study aimed to establish a discriminative model to predict and classify the menopausalstatus of breast cancer patients with CIA.Methods: This is a single center hospital-based study from 2013 to 2016. The menopausal age distribution andaccumulated incidence rate of CIA are described. Multivariate models were adjusted for established and potentialconfounding factors including age, serum concentration of estradiol (E2) and follicle-stimulating hormone (FSH),feeding, pregnancy, parity, abortions, and body mass index (BMI). The odds ratio (OR) and 95% confidenceinterval (95% CI) of different risk factors were estimated.Results: A total of 1,796 breast cancer patients were included in this study, among whom, 1,175 (65.42%) werepremenopausal patients and 621 (34.58%) were post-menopause patients. Five hundred and fifty patients wereincluded in CIA analysis, and a cumulative CIA rate of 81.64% was found in them. Age (OR: 1.856, 95% CI:1.732-1.990), serum concentration of E2 (OR: 0.976, 95% CI: 0.972-0.980) and FSH (OR: 1.060, 95% CI:1.053-i.066), and menarche age (OR: 1.074, 95% CI: 1.009-1.144) were found to be associated with the patients'menopausal status. According to multivariate analysis, the discriminative model to predict the menopausal status isLogit (P)=-28.396+0.536Age-0.014E2+0.031FSH. The sensitivities for this model were higher than 85%, and itsspecificities were higher than 89%.Conclusions: The discriminative model obtained from this study for predicting menstrual state is important forpremenopausal patients with CIA. This model has high specificity and sensitivity and should be prudently used.展开更多
The radar ray path equations are used to determine the physical location of each radar measurement. These equations are necessary for mapping radar data to computational grids for diagnosis, display and numerical weat...The radar ray path equations are used to determine the physical location of each radar measurement. These equations are necessary for mapping radar data to computational grids for diagnosis, display and numerical weather prediction (NWP). They are also used to determine the forward operators for assimilation of radar data into forecast models. In this paper, a stepwise ray tracing method is developed. The influence of the atmospheric refractive index on the ray path equations at different locations related to an intense cold front is examined against the ray path derived from the new tracing method. It is shown that the radar ray path is not very sensitive to sharp vertical gradients of refractive index caused by the strong temperature inversion and large moisture gradient in this case. In the paper, the errors caused by using the simplified straight ray path equations are also examined. It is found that there will be significant errors in the physical location of radar measurements if the earth's curvature is not considered, especially at lower elevation angles. A reduced form of the equation for beam height calculation is derived using Taylor series expansion. It is computationally more efficient and also avoids the need to use double precision variables to mitigate the small difference between two large terms in the original form. The accuracy of this reduced form is found to be sufficient for modeling use.展开更多
Because they are most sensitive to atmospheric moisture content, radar refractivity observations can provide high-resolution information about the highly variable low-level moisture field. In this study, simulated rad...Because they are most sensitive to atmospheric moisture content, radar refractivity observations can provide high-resolution information about the highly variable low-level moisture field. In this study, simulated radar refractivity-related phase-change data were created using a radar simulator from realistic highresolution model simulation data for a dryline case. These data were analyzed using the 2DVAR system developed specifically for the phase-change data. Two sets of experiments with the simulated observations were performed, one assuming a uniform target spacing of 250 m and one assuming nonuniform spacing between 250 m to 4 km. Several sources of observation error were considered, and their impacts were examined. They included errors due to ground target position uncertainty, typical random errors associated with radar measurements, and gross error due to phase wrapping. Without any additional information, the 2DVAR system was incapable of dealing with phase-wrapped data directly. When there was no phase wrapping in the data, the 2DVAR produced ex- cellent analyses, even in the presence of both position uncertainty and random radar measurement errors. When a separate pre-processing step was applied to unwrap the phase-wrapped data, quality moisture anal- yses were again obtained, although the analyses were smoother due to the reduced effective resolution of the observations by interpolation and smoothing involved in the unwrapping procedure. The unwrapping procedure was effective even when significant differences existed between the analyzed state and the state at a reference time. The results affirm the promise of using radar refractivity phase-change measurements for near-surface moisture analysis.展开更多
Many weather radar networks in the world have now provided polarimetric radar data(PRD)that have the potential to improve our understanding of cloud and precipitation microphysics,and numerical weather prediction(NWP)...Many weather radar networks in the world have now provided polarimetric radar data(PRD)that have the potential to improve our understanding of cloud and precipitation microphysics,and numerical weather prediction(NWP).To realize this potential,an accurate and efficient set of polarimetric observation operators are needed to simulate and assimilate the PRD with an NWP model for an accurate analysis of the model state variables.For this purpose,a set of parameterized observation operators are developed to simulate and assimilate polarimetric radar data from NWP model-predicted hydrometeor mixing ratios and number concentrations of rain,snow,hail,and graupel.The polarimetric radar variables are calculated based on the T-matrix calculation of wave scattering and integrations of the scattering weighted by the particle size distribution.The calculated polarimetric variables are then fitted to simple functions of water content and volumeweighted mean diameter of the hydrometeor particle size distribution.The parameterized PRD operators are applied to an ideal case and a real case predicted by the Weather Research and Forecasting(WRF)model to have simulated PRD,which are compared with existing operators and real observations to show their validity and applicability.The new PRD operators use less than one percent of the computing time of the old operators to complete the same simulations,making it efficient in PRD simulation and assimilation usage.展开更多
In this study, the variation of radio refractivity with respect to temperature and moisture is analyzed. Also, the effects of vertical gradients in temperature and moisture on the propagation paths of electromagnetic ...In this study, the variation of radio refractivity with respect to temperature and moisture is analyzed. Also, the effects of vertical gradients in temperature and moisture on the propagation paths of electromagnetic waves of weather radar are examined for several sites across the United States using several years of sounding data from the National Weather Service. The ray path is important for identifying storm characteristics and for properly using the radar data in initializing numerical weather prediction models. It is found that during the warm season the radio refractivity gradient is more sensitive to moisture gradients than to temperature gradients. Ray paths from the commonly accepted vertical ray path model are compared to a ray path computed from a stepwise ray tracing algorithm using data from actual soundings. For the sample of about 16 000 soundings examined, we find that only a small fraction of the ray paths diverge significantly from those calculated using a ray path model based on the US Standard Atmosphere. While the problem of ray dueting in the presence of a temperature inversion is fairly well known, we identify the presence of a strong vertical moisture gradient as the culprit in the majority of the cases where significant deviations occurred.展开更多
As part of NOAA's "Warn-On-Forecast" initiative, a convective-scale data assimilation and prediction system was developed using the WRF-ARW model and ARPS 3DVAR data assimilation technique. The system was then eval...As part of NOAA's "Warn-On-Forecast" initiative, a convective-scale data assimilation and prediction system was developed using the WRF-ARW model and ARPS 3DVAR data assimilation technique. The system was then evaluated using retrospective short-range ensemble analyses and probabilistic forecasts of the tornadic supercell outbreak event that occurred on 24 May 2011 in Oklahoma, USA. A 36-member multi-physics ensemble system provided the initial and boundary conditions for a 3-km convective-scale ensemble system. Radial velocity and reflectivity observations from four WSR-88 Ds were assimilated into the ensemble using the ARPS 3DVAR technique. Five data assimilation and forecast experiments were conducted to evaluate the sensitivity of the system to data assimilation frequencies, in-cloud temperature adjustment schemes, and fixed- and mixed-microphysics ensembles. The results indicated that the experiment with 5-min assimilation frequency quickly built up the storm and produced a more accurate analysis compared with the 10-min assimilation frequency experiment. The predicted vertical vorticity from the moist-adiabatic in-cloud temperature adjustment scheme was larger in magnitude than that from the latent heat scheme. Cycled data assimilation yielded good forecasts, where the ensemble probability of high vertical vorticity matched reasonably well with the observed tornado damage path. Overall, the results of the study suggest that the 3DVAR analysis and forecast system can provide reasonable forecasts of tornadic supercell storms.展开更多
Most basal-like breast cancers(BLBCs)have a poor prognosis and high crossover with triple-negative breast cancers(TNBCs).However,approximately 50%of TNBC patients develop chemoresistance.^(1) Dexamethasone reportedly ...Most basal-like breast cancers(BLBCs)have a poor prognosis and high crossover with triple-negative breast cancers(TNBCs).However,approximately 50%of TNBC patients develop chemoresistance.^(1) Dexamethasone reportedly induces Krüppel-like factor 5(KLF5)and can cause docetaxel and cisplatin resistance in TNBC.A super-enhancer can maintain the transcription of KLF5.展开更多
FeOx-CeO2 mixed oxides with increasing Fe/(Ce+Fe) atomic ratio (1-20 mol%) were prepared by sol-gel method and characterized by X-ray powder diffraction (XRD), Brunauer-Emrnett-Teller (BET) and Hydrogen tempe...FeOx-CeO2 mixed oxides with increasing Fe/(Ce+Fe) atomic ratio (1-20 mol%) were prepared by sol-gel method and characterized by X-ray powder diffraction (XRD), Brunauer-Emrnett-Teller (BET) and Hydrogen temperature-programmed reduction (H2-TPR) techniques. The dynamic oxygen storage capacity (DOSC) was investigated by mass spectrometry with CO/O2 transient pulses. The powder XRD data following Rietveld refinement revealed that the solubility limit of iron oxides in the CeO2 was 5 mol% based on Fe/(Ce+Fe). The lattice parameters experienced a decrease followed by an increase due to the influence of the maximum solubility limit of iron oxides in the CeO2. TPR analysis revealed that Fe introduction into ceria strongly modified the textual and structural properties, which influenced the oxygen handling properties. DOSC results revealed that Ce-based materials containing Fe oxides with multiple valences contribute to the majority of DOSC. The kinetic analysis indicated that the calculated apparent kinetic parameters obey the compensation effect. The three-way catalytic performance for Pd-only catalysts based on the Fe doping support exhibited the redundant iron species separated out of the CeO2 and interacted with the ceria and Pd species on the surface, which seriously influenced the catalytic properties, especially after hydrothermal aging treatment.展开更多
基金supported by the NOAA (Grant Nos. NA16AOR4320115 and NA11OAR4320072)NSF (Grant No. AGS-1341878)
文摘After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve weather observations,quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction(NWP) models.In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation.
文摘Background: Intraductal administration of cytotoxic agents has been shown to inhibit the development of breast cancer in animal models. The object of this study was to demonstrate the safety of intraductal delivery cytotoxic agents in patients prior to mastectomy. This method is hopeful to be developed as a chemoprevention approach in patients with pre-malignant or non-invasive ductal lesions to prevent breast cancer which will be further developed.Methods: Two drugs, pegylated liposomal doxorubicin(PLD) and carboplatin were administered at three dose levels(PLD: 10, 20, 50 mg and carboplatin 60, 120, 300 mg). There were five subjects in each group with 15 subjects treated with each drug once. Venous blood samples were obtained for pharmacokinetic analysis. The breast was removed surgically 2-5 days post administration and the treated ducts were marked to enable identification on pathological evaluation. Results: Intraductal administration was generally well-tolerated with mild, transient breast discomfort. In the carboplatin arm, three women at the 300 mg dose experienced mild nausea and vomiting. In the PLD arm most women had mild erythema and swelling of the breast over the 72 hours following the drug administration. Patients receiving the 50 mg dose experienced local erythema until the time of surgery. Pharmacokinetic analysis showed that carboplatin rapidly entered systemic circulation with an early peak time(T max -30 min) with a corresponding plasma ultrafiltrate area under the curve(AUC) consistent with the Calvert Formula using estimated glomerular filtration rate(GFR). Total plasma doxorubicin had delayed peak concentration times(T max 48 hours) with a linear dose response and peak concentrations substantially lower than expected from equivalent intravenous injection dosing. No doxorubicinol metabolite was detected in the plasma. Conclusions: This study demonstrates that cytotoxic drugs can be safely administered into breast ducts with minimal toxicity.
基金supported by Chinese Medical Foundation (CMF, No. 313.2215)
文摘Objective: In patients with chemotherapy-induced amenorrhea (CIA), the menopausal status is ambiguous anddifficult to evaluate. This study aimed to establish a discriminative model to predict and classify the menopausalstatus of breast cancer patients with CIA.Methods: This is a single center hospital-based study from 2013 to 2016. The menopausal age distribution andaccumulated incidence rate of CIA are described. Multivariate models were adjusted for established and potentialconfounding factors including age, serum concentration of estradiol (E2) and follicle-stimulating hormone (FSH),feeding, pregnancy, parity, abortions, and body mass index (BMI). The odds ratio (OR) and 95% confidenceinterval (95% CI) of different risk factors were estimated.Results: A total of 1,796 breast cancer patients were included in this study, among whom, 1,175 (65.42%) werepremenopausal patients and 621 (34.58%) were post-menopause patients. Five hundred and fifty patients wereincluded in CIA analysis, and a cumulative CIA rate of 81.64% was found in them. Age (OR: 1.856, 95% CI:1.732-1.990), serum concentration of E2 (OR: 0.976, 95% CI: 0.972-0.980) and FSH (OR: 1.060, 95% CI:1.053-i.066), and menarche age (OR: 1.074, 95% CI: 1.009-1.144) were found to be associated with the patients'menopausal status. According to multivariate analysis, the discriminative model to predict the menopausal status isLogit (P)=-28.396+0.536Age-0.014E2+0.031FSH. The sensitivities for this model were higher than 85%, and itsspecificities were higher than 89%.Conclusions: The discriminative model obtained from this study for predicting menstrual state is important forpremenopausal patients with CIA. This model has high specificity and sensitivity and should be prudently used.
基金This work was supported by US NSF ATM-0129892,ATM-0331756,ATM-0331594 and EEC-0313747,and D0T-FAA grant NA17RJ1227-01The first author was also partly supported by the National Natural Science Foundation of China for young investigators(Grant No.40505022)+1 种基金Ming Xue was also supported by the 0utstanding 0verseas Scholars Award of the Chinese Academy of Sciences(Grant No.2004-2-7)Graphic plots were generated by the GNUPL0T graphics package.
文摘The radar ray path equations are used to determine the physical location of each radar measurement. These equations are necessary for mapping radar data to computational grids for diagnosis, display and numerical weather prediction (NWP). They are also used to determine the forward operators for assimilation of radar data into forecast models. In this paper, a stepwise ray tracing method is developed. The influence of the atmospheric refractive index on the ray path equations at different locations related to an intense cold front is examined against the ray path derived from the new tracing method. It is shown that the radar ray path is not very sensitive to sharp vertical gradients of refractive index caused by the strong temperature inversion and large moisture gradient in this case. In the paper, the errors caused by using the simplified straight ray path equations are also examined. It is found that there will be significant errors in the physical location of radar measurements if the earth's curvature is not considered, especially at lower elevation angles. A reduced form of the equation for beam height calculation is derived using Taylor series expansion. It is computationally more efficient and also avoids the need to use double precision variables to mitigate the small difference between two large terms in the original form. The accuracy of this reduced form is found to be sufficient for modeling use.
基金supported by the National Science Foundation (Grant No. AGS-0750790)supported by the NSF grants (Grant Nos. AGS-0802888,OCI-0905040,AGS-0941491,AGS-1046171,and AGS-1046081)
文摘Because they are most sensitive to atmospheric moisture content, radar refractivity observations can provide high-resolution information about the highly variable low-level moisture field. In this study, simulated radar refractivity-related phase-change data were created using a radar simulator from realistic highresolution model simulation data for a dryline case. These data were analyzed using the 2DVAR system developed specifically for the phase-change data. Two sets of experiments with the simulated observations were performed, one assuming a uniform target spacing of 250 m and one assuming nonuniform spacing between 250 m to 4 km. Several sources of observation error were considered, and their impacts were examined. They included errors due to ground target position uncertainty, typical random errors associated with radar measurements, and gross error due to phase wrapping. Without any additional information, the 2DVAR system was incapable of dealing with phase-wrapped data directly. When there was no phase wrapping in the data, the 2DVAR produced ex- cellent analyses, even in the presence of both position uncertainty and random radar measurement errors. When a separate pre-processing step was applied to unwrap the phase-wrapped data, quality moisture anal- yses were again obtained, although the analyses were smoother due to the reduced effective resolution of the observations by interpolation and smoothing involved in the unwrapping procedure. The unwrapping procedure was effective even when significant differences existed between the analyzed state and the state at a reference time. The results affirm the promise of using radar refractivity phase-change measurements for near-surface moisture analysis.
基金the University of Oklahoma(OU)Supercomputing Center for Education&Research(OSCER).
文摘Many weather radar networks in the world have now provided polarimetric radar data(PRD)that have the potential to improve our understanding of cloud and precipitation microphysics,and numerical weather prediction(NWP).To realize this potential,an accurate and efficient set of polarimetric observation operators are needed to simulate and assimilate the PRD with an NWP model for an accurate analysis of the model state variables.For this purpose,a set of parameterized observation operators are developed to simulate and assimilate polarimetric radar data from NWP model-predicted hydrometeor mixing ratios and number concentrations of rain,snow,hail,and graupel.The polarimetric radar variables are calculated based on the T-matrix calculation of wave scattering and integrations of the scattering weighted by the particle size distribution.The calculated polarimetric variables are then fitted to simple functions of water content and volumeweighted mean diameter of the hydrometeor particle size distribution.The parameterized PRD operators are applied to an ideal case and a real case predicted by the Weather Research and Forecasting(WRF)model to have simulated PRD,which are compared with existing operators and real observations to show their validity and applicability.The new PRD operators use less than one percent of the computing time of the old operators to complete the same simulations,making it efficient in PRD simulation and assimilation usage.
基金U. S. NSF Grant Nos. ATM-0331756, ATM-0331594, ATM-0530814 and EEC-0313747, and by DOT-FAA Grant NA17RJ1227-01the National Natural Science Foun- dation of China under Grant Nos. 40620120437 and 40505022
文摘In this study, the variation of radio refractivity with respect to temperature and moisture is analyzed. Also, the effects of vertical gradients in temperature and moisture on the propagation paths of electromagnetic waves of weather radar are examined for several sites across the United States using several years of sounding data from the National Weather Service. The ray path is important for identifying storm characteristics and for properly using the radar data in initializing numerical weather prediction models. It is found that during the warm season the radio refractivity gradient is more sensitive to moisture gradients than to temperature gradients. Ray paths from the commonly accepted vertical ray path model are compared to a ray path computed from a stepwise ray tracing algorithm using data from actual soundings. For the sample of about 16 000 soundings examined, we find that only a small fraction of the ray paths diverge significantly from those calculated using a ray path model based on the US Standard Atmosphere. While the problem of ray dueting in the presence of a temperature inversion is fairly well known, we identify the presence of a strong vertical moisture gradient as the culprit in the majority of the cases where significant deviations occurred.
基金provided by the NOAA/Office of Oceanic and Atmospheric Research under the NOAA–University of Oklahoma Cooperative Agreement#NA17RJ1227the U.S.Department of Commerce+2 种基金NSF AGS-1341878the National Natural Science Foundation of China(Project No.41305092)the International S&T Cooperation Program of China(ISTCP)(Grant No.2011DFG23210)
文摘As part of NOAA's "Warn-On-Forecast" initiative, a convective-scale data assimilation and prediction system was developed using the WRF-ARW model and ARPS 3DVAR data assimilation technique. The system was then evaluated using retrospective short-range ensemble analyses and probabilistic forecasts of the tornadic supercell outbreak event that occurred on 24 May 2011 in Oklahoma, USA. A 36-member multi-physics ensemble system provided the initial and boundary conditions for a 3-km convective-scale ensemble system. Radial velocity and reflectivity observations from four WSR-88 Ds were assimilated into the ensemble using the ARPS 3DVAR technique. Five data assimilation and forecast experiments were conducted to evaluate the sensitivity of the system to data assimilation frequencies, in-cloud temperature adjustment schemes, and fixed- and mixed-microphysics ensembles. The results indicated that the experiment with 5-min assimilation frequency quickly built up the storm and produced a more accurate analysis compared with the 10-min assimilation frequency experiment. The predicted vertical vorticity from the moist-adiabatic in-cloud temperature adjustment scheme was larger in magnitude than that from the latent heat scheme. Cycled data assimilation yielded good forecasts, where the ensemble probability of high vertical vorticity matched reasonably well with the observed tornado damage path. Overall, the results of the study suggest that the 3DVAR analysis and forecast system can provide reasonable forecasts of tornadic supercell storms.
基金supported by the National Key R&D Program of China(No.2020YFA0112300)the National Natural Science Foundation of China(No.81830087,U2102203,82173014,81872414)+5 种基金the Yunnan Fundamental Research Projects(China)(No.202101AS070050,202001AW070018)major projects for fundamental research of Yunnan Province,China(No.202201BC070002)CAS"Light of West China"”Young Scholar Program,and Yunnan Revitalization Talent Support Program(China)(Yunling Shcolar Project and Young Talent Project)the Guangdong Foundation Committee for Basic and Applied Basic Research projects(China)(No.2022A1515012420)the Guangdong Medical University Affiliated Hospital Competitive Clinical Study(China)(No.LCYJ2021B003)the Guangdong Province Characteristic Innovation Projects(China)(No.2021KTSCX037).
文摘Most basal-like breast cancers(BLBCs)have a poor prognosis and high crossover with triple-negative breast cancers(TNBCs).However,approximately 50%of TNBC patients develop chemoresistance.^(1) Dexamethasone reportedly induces Krüppel-like factor 5(KLF5)and can cause docetaxel and cisplatin resistance in TNBC.A super-enhancer can maintain the transcription of KLF5.
基金support the National HighTech Research and Development Program of China (No.2011AA03A405)
文摘FeOx-CeO2 mixed oxides with increasing Fe/(Ce+Fe) atomic ratio (1-20 mol%) were prepared by sol-gel method and characterized by X-ray powder diffraction (XRD), Brunauer-Emrnett-Teller (BET) and Hydrogen temperature-programmed reduction (H2-TPR) techniques. The dynamic oxygen storage capacity (DOSC) was investigated by mass spectrometry with CO/O2 transient pulses. The powder XRD data following Rietveld refinement revealed that the solubility limit of iron oxides in the CeO2 was 5 mol% based on Fe/(Ce+Fe). The lattice parameters experienced a decrease followed by an increase due to the influence of the maximum solubility limit of iron oxides in the CeO2. TPR analysis revealed that Fe introduction into ceria strongly modified the textual and structural properties, which influenced the oxygen handling properties. DOSC results revealed that Ce-based materials containing Fe oxides with multiple valences contribute to the majority of DOSC. The kinetic analysis indicated that the calculated apparent kinetic parameters obey the compensation effect. The three-way catalytic performance for Pd-only catalysts based on the Fe doping support exhibited the redundant iron species separated out of the CeO2 and interacted with the ceria and Pd species on the surface, which seriously influenced the catalytic properties, especially after hydrothermal aging treatment.