In this paper, we establish a sharp function estimate for the multilinear integral operators associated to the pseudo-differential operators. As the application, we obtain the L<sup>p</sup> (1 p norm ...In this paper, we establish a sharp function estimate for the multilinear integral operators associated to the pseudo-differential operators. As the application, we obtain the L<sup>p</sup> (1 p norm inequalities for the multilinear operators.展开更多
The morphology of active layer in bulk heterojunction(BHJ) organic solar cells is decisive to the device performance. Previous works have shown that the solvent engineering is an effective method to optimize the morph...The morphology of active layer in bulk heterojunction(BHJ) organic solar cells is decisive to the device performance. Previous works have shown that the solvent engineering is an effective method to optimize the morphology of active layer. However, screening the proper solvent is a tedious task, and we know very little about how to select a proper solvent for a particular system, especially for polymer/nonfullerene blend systems. Here, we combined the spectroscopic analysis in various solvent mixtures during film-forming process to reveal the relationship among the cosolvent characteristics, film-forming kinetics and film morphology. In this article, P3 HT/O-IDTBR blend was selected as model system due to being facile synthesized under a large-scale. Chlorobenzene(CB) was selected as main solvent, and the cosolvents were grouped into three categories according to its boiling point(bp) compared to CB.The cosolvents with lower bp, like chloroform(CF), can facilitate a faster film-forming process, reducing the domain size but sacrificing the crystallinity of both components. For the cosolvents with higher bp,like o-dichlorobenzene(DCB) and 1,2,4-trichlorobenzene(TCB), the self-organization process of P3 HT and O-IDTBR is separated and its duration was extended, constructing highly crystalline nanointerpenetrating network. However, the cosolvents with very high bp, such as chlornaphthalene(CN),would residue in film and keep P3 HT and O-IDTBR self-organizing for longer time, leading to larger phase separation. This work systematically investigated the effect of cosolvent on the film-forming kinetics, and proposed a guideline of how to select a proper cosolvent according to the crystallinity and domain size of active layer.展开更多
Objective: To study the significance of c-myc and c-erbB-2 oncogene expression in gastric cancer. Methods: 81 gastric cancer specimens were detected for c-myc and c-erbB-2 oncogene amplification using non-radioactive ...Objective: To study the significance of c-myc and c-erbB-2 oncogene expression in gastric cancer. Methods: 81 gastric cancer specimens were detected for c-myc and c-erbB-2 oncogene amplification using non-radioactive in situ hybridization method. Results: The amplification rates for c-myc and c-erbB-2 were 67.9% and 50.6% respectively, and there were significant correlation in the amplification of these two genes (χ2 = 7.26, P Conclusions: The amplification of c-myc and c-erbB-2 may play an important role in gastric cancer development, and these two genes may have synergistic effect.展开更多
Prostate cancer(PCa)is a pernicious tumor with high heterogeneity,which creates a conundrum for making a precise diagnosis and choosing an optimal treatment approach.Multiparametric magnetic resonance imaging(mp-MRI)w...Prostate cancer(PCa)is a pernicious tumor with high heterogeneity,which creates a conundrum for making a precise diagnosis and choosing an optimal treatment approach.Multiparametric magnetic resonance imaging(mp-MRI)with anatomical and functional sequences has evolved as a routine and significant paradigm for the detection and characterization of PCa.Moreover,using radiomics to extract quantitative data has emerged as a promising field due to the rapid growth of artificial intelligence(AI)and image data processing.Radiomics acquires novel imaging biomarkers by extracting imaging signatures and establishes models for precise evaluation.Radiomics models provide a reliable and noninvasive alternative to aid in precision medicine,demonstrating advantages over traditional models based on clinicopathological parameters.The purpose of this review is to provide an overview of related studies of radiomics in PCa,specifically around the development and validation of radiomics models using MRI-derived image features.The current landscape of the literature,focusing mainly on PCa detection,aggressiveness,and prognosis evaluation,is reviewed and summarized.Rather than studies that exclusively focus on image biomarker identification and method optimization,models with high potential for universal clinical implementation are identified.Furthermore,we delve deeper into the critical concerns that can be addressed by different models and the obstacles that may arise in a clinical scenario.This review will encourage researchers to design models based on actual clinical needs,as well as assist urologists in gaining a better understanding of the promising results yielded by radiomics.展开更多
This study aims to discriminate between leucine-rich glioma-inactivated 1(LGI1)antibody encephalitis and gammaaminobutyric acid B(GABAB)receptor antibody encephalitis using a convolutional neural network(CNN)model.A t...This study aims to discriminate between leucine-rich glioma-inactivated 1(LGI1)antibody encephalitis and gammaaminobutyric acid B(GABAB)receptor antibody encephalitis using a convolutional neural network(CNN)model.A total of 81 patients were recruited for this study.ResNet18,VGG16,and ResNet50 were trained and tested separately using 3828 positron emission tomography image slices that contained the medial temporal lobe(MTL)or basal ganglia(BG).Leave-one-out cross-validation at the patient level was used to evaluate the CNN models.The receiver operating characteristic(ROC)curve and the area under the ROC curve(AUC)were generated to evaluate the CNN models.Based on the prediction results at slice level,a decision strategy was employed to evaluate the CNN models’performance at patient level.The ResNet18 model achieved the best performance at the slice(AUC=0.86,accuracy=80.28%)and patient levels(AUC=0.98,accuracy=96.30%).Specifically,at the slice level,73.28%(1445/1972)of image slices with GABAB receptor antibody encephalitis and 87.72%(1628/1856)of image slices with LGI1 antibody encephalitis were accurately detected.At the patient level,94.12%(16/17)of patients with GABAB receptor antibody encephalitis and 96.88%(62/64)of patients with LGI1 antibody encephalitis were accurately detected.Heatmaps of the image slices extracted using gradient-weighted class activation mapping indicated that the model focused on the MTL and BG for classification.In general,the ResNet18 model is a potential approach for discriminating between LGI1 and GABAB receptor antibody encephalitis.Metabolism in the MTL and BG is important for discriminating between these two encephalitis subtypes.展开更多
Majority of type 2 diabetes mellitus(T2DM)patients are highly susceptible to several forms of cognitive impairments,particularly dementia.However,the underlying neural mechanism of these cognitive impairments remains ...Majority of type 2 diabetes mellitus(T2DM)patients are highly susceptible to several forms of cognitive impairments,particularly dementia.However,the underlying neural mechanism of these cognitive impairments remains unclear.We aimed to investigate the correlation between whole brain resting state functional connections(RSFCs)and the cognitive status in 95 patients with T2DM.We constructed an elastic net model to estimate the Montreal Cognitive Assessment(MoCA)scores,which served as an index of the cognitive status of the patients,and to select the RSFCs for further prediction.Subsequently,we utilized a machine learning technique to evaluate the discriminative ability of the connectivity pattern associated with the selected RSFCs.The estimated and chronological MoCA scores were significantly correlated with R=0.81 and the mean absolute error(MAE)=1.20.Additionally,cognitive impairments of patients with T2DM can be identified using the RSFC pattern with classification accuracy of 90.54%and the area under the receiver operating characteristic(ROC)curve(AUC)of 0.9737.This connectivity pattern not only included the connections between regions within the default mode network(DMN),but also the functional connectivity between the task-positive networks and the DMN,as well as those within the task-positive networks.The results suggest that an RSFC pattern could be regarded as a potential biomarker to identify the cognitive status of patients with T2DM.展开更多
To obtain the optimal seedling taking trajectory,this study proposed the adjustment of the total transmission ratio curve by using human-computer interaction.On the basis of this design method,a planetary non-circular...To obtain the optimal seedling taking trajectory,this study proposed the adjustment of the total transmission ratio curve by using human-computer interaction.On the basis of this design method,a planetary non-circular gear mechanism was designed that can realize the twice unequal amplitude transmission ratio to meet the seedling harvesting requirements.The cubic non-uniform B-spline curve was used to fit the twice unequal amplitude transmission ratio curve,and the transmission ratio was freely distributed in two levels.The seedling pick-up mechanism was designed by controlling the seedling taking track and the corresponding attitude directly through the local section of the total transmission ratio,and the gear pitch curve was directly controlled by the transmission ratio.The kinematics model of the seedling pick-up mechanism was also established.Furthermore,the influence of the total transmission ratio on the seedling picking track,the ratio of the wave crest to the amplitude,and the mechanism parameters were discussed.A human-computer interactive optimization software was developed using Matlab,and a set of optimal parameters for the seedling pick-up mechanism was obtained to meet the transplanting requirements.By using the Adams software,the virtual prototype simulation of the seedling pick-up mechanism was completed,and the idle experiment for the track and attitude of the prototype was conducted through high-speed camera technology.The theoretical,simulated,and experimental trajectories were consistent with each other.Results revealed that the success rate of the seedling picking exceeded 90%when the rotation speeds were 40 r/min,50 r/min,and 60 r/min,and the qualified rate of the matrix decreased with the increase in rotating speed.Moreover,the number of damaged plants increased with the increase in rotating speed.The experimental results showed that the seedling pick-up mechanism designed using the proposed method demonstrated a good effect and met the required seedling picking performance.展开更多
The inte rmixed phase is important in effective charge separation due to the formation of cascaded energy landscape between intermixed phase and pure phases in polymer/fullerene solar cells.However,the quantitative re...The inte rmixed phase is important in effective charge separation due to the formation of cascaded energy landscape between intermixed phase and pure phases in polymer/fullerene solar cells.However,the quantitative relationship between the charge separation and the content of intermixed phase has not been investigated clearly so far.Here,we proposed to tune the content of the polymer/PC71BM intermixed phase by cha nging the polymer solution conformatio n.Poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene](PBTTT)and PC71 BM was selected as a model system.The organization of the PBTTT in solution promotes the formation of ordered aggregates as aging time increases,the interdigitation of side-chains restricts the intercalation of PC71 BM.Therefore,the intermixed phase formed by intercalation PC71 BM to PBTTT side chain can be controlled.When the aging time increasing from 0 to 80 min,the extent of inte rcalation gradually from almost complete intercalated phase to almost non-intercalated.As the content of intercalated phase is about 11%,the charge dissociation is most efficie nt and short circuit current(Jsc)increased from 1.60 mA/cm2 to 4.94 mA/cm2,leading to optimized device performance.展开更多
This work aimed at investigating the possibility and effectiveness of osteoinductive calcium phosphate(CaP)ceramics to close the drilled skull holes and prevent the postoperative cerebrospinal fluid(CSF)leaking in chi...This work aimed at investigating the possibility and effectiveness of osteoinductive calcium phosphate(CaP)ceramics to close the drilled skull holes and prevent the postoperative cerebrospinal fluid(CSF)leaking in children’s endoscopic neurosurgery.Five children patients(four boys and one girl,3-to 8-years old)underwent the surgery,in which the endoscopic third ventriculostomy(ETV)was operated in four cases of hydrocephalus,and biopsy and ETV were both performed in one case of pineal tumor.The drilled skull holes were filled with the commercial osteoinductive CaP ceramics.The patients were followed up by CT scan at 1,7 days,3 and 6 months postoperatively.All the five cases were successful,and the holes were closed well after filled with the ceramics.The follow-up survey showed that no CSF leaking or rejection reaction was found.The CT scan indicated that the drilled holes began healing at 7 days postoperatively,and a relatively complete healing happened at 6 months postoperatively.The excellent ability of the CaP ceramics to induce bone regeneration was also confirmed by repairing the skull defects in a monkey model.The results of μ-CT and histological analysis showed that a bony structure with irregular array occurred at the defect area,and the newly formed bone volume density reached 65.7%.In conclusion,the osteoinductive CaP ceramics could be an ideal material to treat the drilled skull holes in children’s endoscopic neurosurgery and prevent CSF leaking afterwards.However,further investigation with more cases and longer follow-up was required to evaluate the clinical effect.展开更多
文摘In this paper, we establish a sharp function estimate for the multilinear integral operators associated to the pseudo-differential operators. As the application, we obtain the L<sup>p</sup> (1 p norm inequalities for the multilinear operators.
基金supported by the National Natural Science Foundation of China (51773203, 51903211)the Fundamental Research Funds for the Central Universities (D5000200273)。
文摘The morphology of active layer in bulk heterojunction(BHJ) organic solar cells is decisive to the device performance. Previous works have shown that the solvent engineering is an effective method to optimize the morphology of active layer. However, screening the proper solvent is a tedious task, and we know very little about how to select a proper solvent for a particular system, especially for polymer/nonfullerene blend systems. Here, we combined the spectroscopic analysis in various solvent mixtures during film-forming process to reveal the relationship among the cosolvent characteristics, film-forming kinetics and film morphology. In this article, P3 HT/O-IDTBR blend was selected as model system due to being facile synthesized under a large-scale. Chlorobenzene(CB) was selected as main solvent, and the cosolvents were grouped into three categories according to its boiling point(bp) compared to CB.The cosolvents with lower bp, like chloroform(CF), can facilitate a faster film-forming process, reducing the domain size but sacrificing the crystallinity of both components. For the cosolvents with higher bp,like o-dichlorobenzene(DCB) and 1,2,4-trichlorobenzene(TCB), the self-organization process of P3 HT and O-IDTBR is separated and its duration was extended, constructing highly crystalline nanointerpenetrating network. However, the cosolvents with very high bp, such as chlornaphthalene(CN),would residue in film and keep P3 HT and O-IDTBR self-organizing for longer time, leading to larger phase separation. This work systematically investigated the effect of cosolvent on the film-forming kinetics, and proposed a guideline of how to select a proper cosolvent according to the crystallinity and domain size of active layer.
文摘Objective: To study the significance of c-myc and c-erbB-2 oncogene expression in gastric cancer. Methods: 81 gastric cancer specimens were detected for c-myc and c-erbB-2 oncogene amplification using non-radioactive in situ hybridization method. Results: The amplification rates for c-myc and c-erbB-2 were 67.9% and 50.6% respectively, and there were significant correlation in the amplification of these two genes (χ2 = 7.26, P Conclusions: The amplification of c-myc and c-erbB-2 may play an important role in gastric cancer development, and these two genes may have synergistic effect.
基金supported by the Beijing Natural Science Foundation(Nos.Z200027 and L212051)the Cohort Construction Project of Peking University Third Hospital(No.BYSYDL2021012),the Medicine-X Project of Peking University Health Science Center(No.BMU2022MX014)the National Natural Science Foundation of China(No.61871004).
文摘Prostate cancer(PCa)is a pernicious tumor with high heterogeneity,which creates a conundrum for making a precise diagnosis and choosing an optimal treatment approach.Multiparametric magnetic resonance imaging(mp-MRI)with anatomical and functional sequences has evolved as a routine and significant paradigm for the detection and characterization of PCa.Moreover,using radiomics to extract quantitative data has emerged as a promising field due to the rapid growth of artificial intelligence(AI)and image data processing.Radiomics acquires novel imaging biomarkers by extracting imaging signatures and establishes models for precise evaluation.Radiomics models provide a reliable and noninvasive alternative to aid in precision medicine,demonstrating advantages over traditional models based on clinicopathological parameters.The purpose of this review is to provide an overview of related studies of radiomics in PCa,specifically around the development and validation of radiomics models using MRI-derived image features.The current landscape of the literature,focusing mainly on PCa detection,aggressiveness,and prognosis evaluation,is reviewed and summarized.Rather than studies that exclusively focus on image biomarker identification and method optimization,models with high potential for universal clinical implementation are identified.Furthermore,we delve deeper into the critical concerns that can be addressed by different models and the obstacles that may arise in a clinical scenario.This review will encourage researchers to design models based on actual clinical needs,as well as assist urologists in gaining a better understanding of the promising results yielded by radiomics.
基金grants from the Beijing Natural Science Foundation-Haidian Original Innovation Joint Foundation,No.L222033the National Key Research and Development Program of China“Common Disease Prevention and Control Research”Key Project,No.2022YFC2503800+2 种基金the National Natural Science Foundation of China,No.81771143the Beijing Natural Science Foundation,No.7192054and the National Key Research and Development Program of China,No.2018YFC1315201.
文摘This study aims to discriminate between leucine-rich glioma-inactivated 1(LGI1)antibody encephalitis and gammaaminobutyric acid B(GABAB)receptor antibody encephalitis using a convolutional neural network(CNN)model.A total of 81 patients were recruited for this study.ResNet18,VGG16,and ResNet50 were trained and tested separately using 3828 positron emission tomography image slices that contained the medial temporal lobe(MTL)or basal ganglia(BG).Leave-one-out cross-validation at the patient level was used to evaluate the CNN models.The receiver operating characteristic(ROC)curve and the area under the ROC curve(AUC)were generated to evaluate the CNN models.Based on the prediction results at slice level,a decision strategy was employed to evaluate the CNN models’performance at patient level.The ResNet18 model achieved the best performance at the slice(AUC=0.86,accuracy=80.28%)and patient levels(AUC=0.98,accuracy=96.30%).Specifically,at the slice level,73.28%(1445/1972)of image slices with GABAB receptor antibody encephalitis and 87.72%(1628/1856)of image slices with LGI1 antibody encephalitis were accurately detected.At the patient level,94.12%(16/17)of patients with GABAB receptor antibody encephalitis and 96.88%(62/64)of patients with LGI1 antibody encephalitis were accurately detected.Heatmaps of the image slices extracted using gradient-weighted class activation mapping indicated that the model focused on the MTL and BG for classification.In general,the ResNet18 model is a potential approach for discriminating between LGI1 and GABAB receptor antibody encephalitis.Metabolism in the MTL and BG is important for discriminating between these two encephalitis subtypes.
基金supported by the National Natural Science Foundation of China(Grant Nos.81772012,81227901,61673051,81641168,31470047,81271565,81527805,and61231004)the National Key R&D Program of China(Grant No.2017YFA0205200)the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.2019136)
文摘Majority of type 2 diabetes mellitus(T2DM)patients are highly susceptible to several forms of cognitive impairments,particularly dementia.However,the underlying neural mechanism of these cognitive impairments remains unclear.We aimed to investigate the correlation between whole brain resting state functional connections(RSFCs)and the cognitive status in 95 patients with T2DM.We constructed an elastic net model to estimate the Montreal Cognitive Assessment(MoCA)scores,which served as an index of the cognitive status of the patients,and to select the RSFCs for further prediction.Subsequently,we utilized a machine learning technique to evaluate the discriminative ability of the connectivity pattern associated with the selected RSFCs.The estimated and chronological MoCA scores were significantly correlated with R=0.81 and the mean absolute error(MAE)=1.20.Additionally,cognitive impairments of patients with T2DM can be identified using the RSFC pattern with classification accuracy of 90.54%and the area under the receiver operating characteristic(ROC)curve(AUC)of 0.9737.This connectivity pattern not only included the connections between regions within the default mode network(DMN),but also the functional connectivity between the task-positive networks and the DMN,as well as those within the task-positive networks.The results suggest that an RSFC pattern could be regarded as a potential biomarker to identify the cognitive status of patients with T2DM.
基金the National Natural Science Foundation of China(Grant No.52075497,No.51775512)the National Key Research and Development Program of China(Grant No.2017YFD0700800)the Key Research and Development Projects in Zhejiang Province(Grant No.2018C02046).
文摘To obtain the optimal seedling taking trajectory,this study proposed the adjustment of the total transmission ratio curve by using human-computer interaction.On the basis of this design method,a planetary non-circular gear mechanism was designed that can realize the twice unequal amplitude transmission ratio to meet the seedling harvesting requirements.The cubic non-uniform B-spline curve was used to fit the twice unequal amplitude transmission ratio curve,and the transmission ratio was freely distributed in two levels.The seedling pick-up mechanism was designed by controlling the seedling taking track and the corresponding attitude directly through the local section of the total transmission ratio,and the gear pitch curve was directly controlled by the transmission ratio.The kinematics model of the seedling pick-up mechanism was also established.Furthermore,the influence of the total transmission ratio on the seedling picking track,the ratio of the wave crest to the amplitude,and the mechanism parameters were discussed.A human-computer interactive optimization software was developed using Matlab,and a set of optimal parameters for the seedling pick-up mechanism was obtained to meet the transplanting requirements.By using the Adams software,the virtual prototype simulation of the seedling pick-up mechanism was completed,and the idle experiment for the track and attitude of the prototype was conducted through high-speed camera technology.The theoretical,simulated,and experimental trajectories were consistent with each other.Results revealed that the success rate of the seedling picking exceeded 90%when the rotation speeds were 40 r/min,50 r/min,and 60 r/min,and the qualified rate of the matrix decreased with the increase in rotating speed.Moreover,the number of damaged plants increased with the increase in rotating speed.The experimental results showed that the seedling pick-up mechanism designed using the proposed method demonstrated a good effect and met the required seedling picking performance.
基金partly supported by the National Natural Science Foundation of China(Nos. 5189071, 91833306, 51303177)the Strategic Priority Research Program of the Chinese Academy of Sciences(No. XDB12020300)
文摘The inte rmixed phase is important in effective charge separation due to the formation of cascaded energy landscape between intermixed phase and pure phases in polymer/fullerene solar cells.However,the quantitative relationship between the charge separation and the content of intermixed phase has not been investigated clearly so far.Here,we proposed to tune the content of the polymer/PC71BM intermixed phase by cha nging the polymer solution conformatio n.Poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene](PBTTT)and PC71 BM was selected as a model system.The organization of the PBTTT in solution promotes the formation of ordered aggregates as aging time increases,the interdigitation of side-chains restricts the intercalation of PC71 BM.Therefore,the intermixed phase formed by intercalation PC71 BM to PBTTT side chain can be controlled.When the aging time increasing from 0 to 80 min,the extent of inte rcalation gradually from almost complete intercalated phase to almost non-intercalated.As the content of intercalated phase is about 11%,the charge dissociation is most efficie nt and short circuit current(Jsc)increased from 1.60 mA/cm2 to 4.94 mA/cm2,leading to optimized device performance.
基金This work was financially supported by the National Key Research and Development Program of China(2016YFC1102000,2016YFC1102003)the National Natural Science Foundation of China(81190131,31370973)+1 种基金the Provincial Key Technology Support Program of Sichuan(2015SZ0026)the‘111’Project of China(B16033).
文摘This work aimed at investigating the possibility and effectiveness of osteoinductive calcium phosphate(CaP)ceramics to close the drilled skull holes and prevent the postoperative cerebrospinal fluid(CSF)leaking in children’s endoscopic neurosurgery.Five children patients(four boys and one girl,3-to 8-years old)underwent the surgery,in which the endoscopic third ventriculostomy(ETV)was operated in four cases of hydrocephalus,and biopsy and ETV were both performed in one case of pineal tumor.The drilled skull holes were filled with the commercial osteoinductive CaP ceramics.The patients were followed up by CT scan at 1,7 days,3 and 6 months postoperatively.All the five cases were successful,and the holes were closed well after filled with the ceramics.The follow-up survey showed that no CSF leaking or rejection reaction was found.The CT scan indicated that the drilled holes began healing at 7 days postoperatively,and a relatively complete healing happened at 6 months postoperatively.The excellent ability of the CaP ceramics to induce bone regeneration was also confirmed by repairing the skull defects in a monkey model.The results of μ-CT and histological analysis showed that a bony structure with irregular array occurred at the defect area,and the newly formed bone volume density reached 65.7%.In conclusion,the osteoinductive CaP ceramics could be an ideal material to treat the drilled skull holes in children’s endoscopic neurosurgery and prevent CSF leaking afterwards.However,further investigation with more cases and longer follow-up was required to evaluate the clinical effect.