In view of the inherent poor tribological properties of copper,the reinforcement of copper matrix composites with WC particles presents a promising research area with significant industrial influence.Therefore,in the ...In view of the inherent poor tribological properties of copper,the reinforcement of copper matrix composites with WC particles presents a promising research area with significant industrial influence.Therefore,in the present study,a molecular dynamics approach is used to simulate the process of repeated friction of diamond grinding balls on WC/Cu composites,and the friction force,friction coefficient,abrasion depth,wear rate,abrasion morphology,von-Mises stress,internal defects,workpiece energy,and performance comparison of different layer thicknesses are systematically investigated in the multiple friction process.It is found that the fluctuation amplitude of friction force,friction coefficient,and abrasion depth are smaller and the fluctuation frequency is larger during the initial friction,whereas near the WC phase,there appears extreme values of the above parameters and the von-Mises stress is highly concentrated while the workpiece energy contonues to increase.In the case of the repeated friction,with the increase of friction times,the friction force,friction coefficient,and abrasion depth fluctuation amplitude increase,the fluctuation frequency decreases,the workpiece energy reaches an extreme value near the WC phase,and a large number of dislocations plug,therefore,the region is strengthened.As the distance between the grinding ball and the WC phase decreases,the more obvious the strengthening effect,the stronger the ability of workpiece to resist the wear will be.展开更多
To segment high-resolution remote sensing images(RSIs)accurately on an object level and meet the precise boundary dividing requirement,an improved superpixel segmentation and region merging algorithm is proposed.Simpl...To segment high-resolution remote sensing images(RSIs)accurately on an object level and meet the precise boundary dividing requirement,an improved superpixel segmentation and region merging algorithm is proposed.Simple linear iterative clustering(SLIC)is widely used because of its advantages in performance and effect;however,it causes over-segmentation,which is very disadvantageous to information extraction.In this proposed method,SLIC is firstly adopted for initial superpixel partition.The second stage follows the iterative merging procedure,which uses a hierarchical clustering algorithm and introduces a local binary pattern(LBP)texture feature operator during the process of merging.The experimental results indicate that the proposed method achieved a good segmentation and region merging performance,and worked effectively on cloud detection preprocessing in high-resolution RSIs with cloud and snow overlap situations.展开更多
Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of ...Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of malignant tumors who underwent SBRT in our hospital(Shaanxi Provincial People’s Hospital)from January 2019 to December 2021 with≤5 metastases,≤3 metastatic organs,and metastases with diameters of≤5 cm.According to the clinical data of patients,the dose-fractionation mode of SBRT is mainly determined according to the pathology of the primary tumor,the location of the metastatic tumor,and the important structures around the tumor.The local control,survival and adverse reactions were observed.Results:A total of 219 oligometastatic lesions in 70 patients were treated with SBRT.The median follow-up time was 24 months(12-40 months).The local control rate(LCR)of all target lesions assessed 3 months after radiotherapy was 94.1%;the 1-,2-,and 3-year LCRs were 88.6%,74.6%,and 64.9%,respectively.The median progression-free survival(PFS)was 11.8 months(95%CI,8.9-14.7 months),and the 1-and 2-year PFS rates were 48.6%and 32.6%,respectively;the median overall survival(OS)was 31.9 month(95%CI 26.0-37.8 months),the 1-year OS rate was 84.3%.The local control time,PFS,and OS of patients with metastases≤3 cm were significantly better than those with metastases>3 cm,and the differences were statistically significant(P<0.05).Acute adverse reactions after SBRT treatment in oligometastatic patients were mainly bone marrow suppression and gastrointestinal reactions,with incidence rates of 48.98%and 30.61%,respectively;chronic adverse reactions were mainly pain(bone,muscle),radiation enteritis,and radiation pneumonitis,with incidence rates of 38.57%,30.00%,and 24.29%,respectively.The treatment-related adverse reactions were mainly grade 1,which were all improved after symptomatic treatment,except for one patient with bone metastases from lung cancer who had grade 4 myelosuppression.No grade 4 or 5 adverse events occurred in the other patients.Conclusion:The application of SBRT in the treatment of extracranial oligometastases is safe,effective,and has high tolerability.展开更多
Background:Dual-energy computed tomography(DECT)is purported to accurately distinguish uric acid stones from non-uric acid stones.However,whether DECT can accurately discriminate ammonium urate stones from uric acid s...Background:Dual-energy computed tomography(DECT)is purported to accurately distinguish uric acid stones from non-uric acid stones.However,whether DECT can accurately discriminate ammonium urate stones from uric acid stones remains unknown.Therefore,we aimed to explore whether they can be accurately identified by DECT and to develop a radiomics model to assist in distinguishing them.Methods:This research included two steps.For the first purpose to evaluate the accuracy of DECT in the diagnosis of uric acid stones,178 urolithiasis patients who underwent preoperative DECT between September 2016 and December 2019 were enrolled.For model construction,93,40,and 109 eligible urolithiasis patients treated between February 2013 and October 2022 were assigned to the training,internal validation,and external validation sets,respectively.Radiomics features were extracted from non-contrast CT images,and the least absolute shrinkage and selection operator(LASSO)algorithm was used to develop a radiomics signature.Then,a radiomics model incorporating the radiomics signature and clinical predictors was constructed.The performance of the model(discrimination,calibration,and clinical usefulness)was evaluated.Results:When patients with ammonium urate stones were included in the analysis,the accuracy of DECT in the diagnosis of uric acid stones was significantly decreased.Sixty-two percent of ammonium urate stones were mistakenly diagnosed as uric acid stones by DECT.A radiomics model incorporating the radiomics signature,urine pH value,and urine white blood cell count was constructed.The model achieved good calibration and discrimination{area under the receiver operating characteristic curve(AUC;95%confidence interval[CI]),0.944(0.899-0.989)},which was internally and externally validated with AUCs of 0.895(95%CI,0.796-0.995)and 0.870(95%CI,0.769-0.972),respectively.Decision curve analysis revealed the clinical usefulness of the model.Conclusions:DECT cannot accurately differentiate ammonium urate stones from uric acid stones.Our proposed radiomics model can serve as a complementary diagnostic tool for distinguishing them in vivo.展开更多
Autogenous bone grafts have long been considered the“gold standard”and most effective material in bone regeneration procedures.[1]Autogenous bone grafts are used to repair bone defects caused by nonunion,infection,t...Autogenous bone grafts have long been considered the“gold standard”and most effective material in bone regeneration procedures.[1]Autogenous bone grafts are used to repair bone defects caused by nonunion,infection,tumor resection,and spinal and joint fusion.[2]It has been reported that more than 200,000 autologous bone grafts are performed in the United States each year.[3]Although there are no specific statistics on the annual number of bone grafts performed in China,autologous bone grafting is the most common surgical technique in orthopedics.The iliac crest remains the most common donor site,along with the fibula,ribs,tibial metaphysis,proximal humerus,distal radius,and greater trochanter.[4,5]Various bone-graft options provide different amounts and qualities of cortical,cancellous,and corticocancellous bone.[6,7]Autogenous bone graft is osteogenic,histocompatible,provides structural support.展开更多
Cancer continues to be a major public health issue worldwide.Given the complexity of the etiology and pathophysiology of cancer,challenges always exist at every step of cancer management,including early screening,diag...Cancer continues to be a major public health issue worldwide.Given the complexity of the etiology and pathophysiology of cancer,challenges always exist at every step of cancer management,including early screening,diagnosis,treatment selection,and surveillance.Emerging novel technologies hold promise in addressing a wide range of healthcare problems.Artificial intelligence(AI),which is capable of learning of features from given datasets.展开更多
Diisononyl phthalate （DINP）, considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP ex...Diisononyl phthalate （DINP）, considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP exposure. Research into the mechanisms underlying these effects is urgently needed. In this study we examined the exacerbation effect of long-term dermal exposure to DINP in flnorescein isothiocyanate （FITC）-induced contact hypersensitivity （CHS） in mice, and sought the potential molecular mechanisms. Forty-nine male Balb/c mice were subjected to a 40-day dermal exposure to saline or one of three concentrations of DINP and then three rounds of sensitization with vehicle or 0.5% FITC. The results of a histopathological examination and measurement of ear swelling as well as immunological and inflammatory biomarkers （total-immunoglobulin （Ig）E and Th cytokines） supported the notion that high doses of DINP may aggravate atopic dermatitis. We also showed that melatonin, an antioxidant, could decrease the levels of oxidative stress and alleviate FITC-induced CHS suggesting that oxidative stress may be one of the molecular mechanisms to explain the exacerbation effect induced by DINP.展开更多
The direct addition of aryl C—H bond to carbon-heteroatom double bond by transition-metal-catalyzed C—H activation has been extensively investigated in the past decade. However, the enantioselective intermolecular C...The direct addition of aryl C—H bond to carbon-heteroatom double bond by transition-metal-catalyzed C—H activation has been extensively investigated in the past decade. However, the enantioselective intermolecular C—H addition to aldehyde has not yet been reported and is of significant challenge. Rh(III)-catalyzed highly enantioselective intermolecular C—H addition of aryl oxime ethers to glyoxylates is reported. Chiral mandelic acid esters were obtained in excellent yields (up to 98%) and enantioselectivity (up to 99% ee) in the presence of a chiral CpRh(III) catalyst under mild conditions. The substituents on the Cp ring and BINOL skeleton were responsible for the high enantioselectivity observed. The method displays a broad substrate scope and good functionality tolerance. These results provide not only a promising C—H addition approach but also a proof of concept for developing broader asymmetric C—H addition reactions.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.52005236)the Natural Science Foundation of Gansu Province,China(Grant No.20JR5RA442)。
文摘In view of the inherent poor tribological properties of copper,the reinforcement of copper matrix composites with WC particles presents a promising research area with significant industrial influence.Therefore,in the present study,a molecular dynamics approach is used to simulate the process of repeated friction of diamond grinding balls on WC/Cu composites,and the friction force,friction coefficient,abrasion depth,wear rate,abrasion morphology,von-Mises stress,internal defects,workpiece energy,and performance comparison of different layer thicknesses are systematically investigated in the multiple friction process.It is found that the fluctuation amplitude of friction force,friction coefficient,and abrasion depth are smaller and the fluctuation frequency is larger during the initial friction,whereas near the WC phase,there appears extreme values of the above parameters and the von-Mises stress is highly concentrated while the workpiece energy contonues to increase.In the case of the repeated friction,with the increase of friction times,the friction force,friction coefficient,and abrasion depth fluctuation amplitude increase,the fluctuation frequency decreases,the workpiece energy reaches an extreme value near the WC phase,and a large number of dislocations plug,therefore,the region is strengthened.As the distance between the grinding ball and the WC phase decreases,the more obvious the strengthening effect,the stronger the ability of workpiece to resist the wear will be.
文摘To segment high-resolution remote sensing images(RSIs)accurately on an object level and meet the precise boundary dividing requirement,an improved superpixel segmentation and region merging algorithm is proposed.Simple linear iterative clustering(SLIC)is widely used because of its advantages in performance and effect;however,it causes over-segmentation,which is very disadvantageous to information extraction.In this proposed method,SLIC is firstly adopted for initial superpixel partition.The second stage follows the iterative merging procedure,which uses a hierarchical clustering algorithm and introduces a local binary pattern(LBP)texture feature operator during the process of merging.The experimental results indicate that the proposed method achieved a good segmentation and region merging performance,and worked effectively on cloud detection preprocessing in high-resolution RSIs with cloud and snow overlap situations.
基金Shaanxi Provincial People’s Hospital 2022 Science and Technology Talent Support Program Funding Project-Elite Talents(2022JY-08)Shaanxi Province Key Research and Development Plan(2021SF-306)。
文摘Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of malignant tumors who underwent SBRT in our hospital(Shaanxi Provincial People’s Hospital)from January 2019 to December 2021 with≤5 metastases,≤3 metastatic organs,and metastases with diameters of≤5 cm.According to the clinical data of patients,the dose-fractionation mode of SBRT is mainly determined according to the pathology of the primary tumor,the location of the metastatic tumor,and the important structures around the tumor.The local control,survival and adverse reactions were observed.Results:A total of 219 oligometastatic lesions in 70 patients were treated with SBRT.The median follow-up time was 24 months(12-40 months).The local control rate(LCR)of all target lesions assessed 3 months after radiotherapy was 94.1%;the 1-,2-,and 3-year LCRs were 88.6%,74.6%,and 64.9%,respectively.The median progression-free survival(PFS)was 11.8 months(95%CI,8.9-14.7 months),and the 1-and 2-year PFS rates were 48.6%and 32.6%,respectively;the median overall survival(OS)was 31.9 month(95%CI 26.0-37.8 months),the 1-year OS rate was 84.3%.The local control time,PFS,and OS of patients with metastases≤3 cm were significantly better than those with metastases>3 cm,and the differences were statistically significant(P<0.05).Acute adverse reactions after SBRT treatment in oligometastatic patients were mainly bone marrow suppression and gastrointestinal reactions,with incidence rates of 48.98%and 30.61%,respectively;chronic adverse reactions were mainly pain(bone,muscle),radiation enteritis,and radiation pneumonitis,with incidence rates of 38.57%,30.00%,and 24.29%,respectively.The treatment-related adverse reactions were mainly grade 1,which were all improved after symptomatic treatment,except for one patient with bone metastases from lung cancer who had grade 4 myelosuppression.No grade 4 or 5 adverse events occurred in the other patients.Conclusion:The application of SBRT in the treatment of extracranial oligometastases is safe,effective,and has high tolerability.
基金supported by the China Postdoctoral Science Foundation(Nos.2021TQ0387,2022M713625,and 2021M703709)the National Natural Science Foundation of China(Nos.82203188 and 81825016)+1 种基金Guangdong Provincial Clinical Research Center for Urological Diseases(No.2020B1111170006)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515111119)
文摘Background:Dual-energy computed tomography(DECT)is purported to accurately distinguish uric acid stones from non-uric acid stones.However,whether DECT can accurately discriminate ammonium urate stones from uric acid stones remains unknown.Therefore,we aimed to explore whether they can be accurately identified by DECT and to develop a radiomics model to assist in distinguishing them.Methods:This research included two steps.For the first purpose to evaluate the accuracy of DECT in the diagnosis of uric acid stones,178 urolithiasis patients who underwent preoperative DECT between September 2016 and December 2019 were enrolled.For model construction,93,40,and 109 eligible urolithiasis patients treated between February 2013 and October 2022 were assigned to the training,internal validation,and external validation sets,respectively.Radiomics features were extracted from non-contrast CT images,and the least absolute shrinkage and selection operator(LASSO)algorithm was used to develop a radiomics signature.Then,a radiomics model incorporating the radiomics signature and clinical predictors was constructed.The performance of the model(discrimination,calibration,and clinical usefulness)was evaluated.Results:When patients with ammonium urate stones were included in the analysis,the accuracy of DECT in the diagnosis of uric acid stones was significantly decreased.Sixty-two percent of ammonium urate stones were mistakenly diagnosed as uric acid stones by DECT.A radiomics model incorporating the radiomics signature,urine pH value,and urine white blood cell count was constructed.The model achieved good calibration and discrimination{area under the receiver operating characteristic curve(AUC;95%confidence interval[CI]),0.944(0.899-0.989)},which was internally and externally validated with AUCs of 0.895(95%CI,0.796-0.995)and 0.870(95%CI,0.769-0.972),respectively.Decision curve analysis revealed the clinical usefulness of the model.Conclusions:DECT cannot accurately differentiate ammonium urate stones from uric acid stones.Our proposed radiomics model can serve as a complementary diagnostic tool for distinguishing them in vivo.
基金supported by grants from the Special Project Program of the National Clinical Research Center for Orthopedics,Sports Medicine&Rehabilitation(No.2022-NCRC-000000)Beijing Municipal Natural Science Foundation(No.7232165)
文摘Autogenous bone grafts have long been considered the“gold standard”and most effective material in bone regeneration procedures.[1]Autogenous bone grafts are used to repair bone defects caused by nonunion,infection,tumor resection,and spinal and joint fusion.[2]It has been reported that more than 200,000 autologous bone grafts are performed in the United States each year.[3]Although there are no specific statistics on the annual number of bone grafts performed in China,autologous bone grafting is the most common surgical technique in orthopedics.The iliac crest remains the most common donor site,along with the fibula,ribs,tibial metaphysis,proximal humerus,distal radius,and greater trochanter.[4,5]Various bone-graft options provide different amounts and qualities of cortical,cancellous,and corticocancellous bone.[6,7]Autogenous bone graft is osteogenic,histocompatible,provides structural support.
基金supported by grants from the National Key Research and Development Program of China(2016YFC1302300)the National Natural Science Foundation of China(81621004,81720108029,81930081,91940305)+5 种基金Guangdong Science and Technology Department(2020B1212060018,2020B1212030004)Clinical Innovation Research Program of Bioland Laboratory(2018GZR0201004)Guangzhou Science Technology and Innovation Commission(201803040015)the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(2019BT02Y198)partly supported by Fountain-Valley Life Sciences Fund of University of Chinese Academy of Sciences Education Foundationsupported by the Sun Yat-Sen University Clinical Research 5010 Program(#2018022)。
文摘Cancer continues to be a major public health issue worldwide.Given the complexity of the etiology and pathophysiology of cancer,challenges always exist at every step of cancer management,including early screening,diagnosis,treatment selection,and surveillance.Emerging novel technologies hold promise in addressing a wide range of healthcare problems.Artificial intelligence(AI),which is capable of learning of features from given datasets.
文摘Diisononyl phthalate （DINP）, considered to be an environmentally friendly plasticizer, is now widely used. However, the toxic effects of DINP need to be examined, particularly the effects of long-term dermal DINP exposure. Research into the mechanisms underlying these effects is urgently needed. In this study we examined the exacerbation effect of long-term dermal exposure to DINP in flnorescein isothiocyanate （FITC）-induced contact hypersensitivity （CHS） in mice, and sought the potential molecular mechanisms. Forty-nine male Balb/c mice were subjected to a 40-day dermal exposure to saline or one of three concentrations of DINP and then three rounds of sensitization with vehicle or 0.5% FITC. The results of a histopathological examination and measurement of ear swelling as well as immunological and inflammatory biomarkers （total-immunoglobulin （Ig）E and Th cytokines） supported the notion that high doses of DINP may aggravate atopic dermatitis. We also showed that melatonin, an antioxidant, could decrease the levels of oxidative stress and alleviate FITC-induced CHS suggesting that oxidative stress may be one of the molecular mechanisms to explain the exacerbation effect induced by DINP.
基金National Key R&D Program of China(2021YFA1500100)the National Natural Science Foundation of China(21821002,91856201,22071260)Science and Technology Commission of Shanghai Municipality(21520780100)for generous financial support.
文摘The direct addition of aryl C—H bond to carbon-heteroatom double bond by transition-metal-catalyzed C—H activation has been extensively investigated in the past decade. However, the enantioselective intermolecular C—H addition to aldehyde has not yet been reported and is of significant challenge. Rh(III)-catalyzed highly enantioselective intermolecular C—H addition of aryl oxime ethers to glyoxylates is reported. Chiral mandelic acid esters were obtained in excellent yields (up to 98%) and enantioselectivity (up to 99% ee) in the presence of a chiral CpRh(III) catalyst under mild conditions. The substituents on the Cp ring and BINOL skeleton were responsible for the high enantioselectivity observed. The method displays a broad substrate scope and good functionality tolerance. These results provide not only a promising C—H addition approach but also a proof of concept for developing broader asymmetric C—H addition reactions.
