AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still ...AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still images, comprising twin pictures (surface enhancement and tone enhancement), collected at our university hospital. We defined endoscopic features of adenomatous and non-adenomatous polyps, according to the following parameters:color, surface pattern and vascular pattern. We familiarized the participating endoscopists on optical diagnosis of colorectal polyps using a 20-min didactic training session. All endoscopists were asked to evaluate an image set of 50 colorectal polyps with regard to polyp histology. We classified the diagnoses into high confidence (i.e., cases in which the endoscopist could assign a diagnosis with certainty) and low confidence diagnoses (i.e., cases in which the endoscopist preferred to send the polyp for formal histology). Mean sensitivity, specificity and accuracy per endoscopist/image were computed and differences between groups tested using independent-samples t tests. High vs low confidence diagnoses were compared using the pairedsamples t test. RESULTS:Eleven endoscopists without previous experience on optical diagnosis evaluated a total of 550 images (396 adenomatous, 154 non-adenomatous). Mean sensitivity, specificity and accuracy for diagnosing adenomas were 79.3%, 85.7% and 81.1%, respectively. No significant differences were found between gastroenterologists and trainees regarding performances of optical diagnosis (mean accuracy 78.0%vs 82.9%,P = 0.098). Diminutive lesions were predicted with a lower mean accuracy as compared to non-diminutive lesions (74.2% vs 93.1%, P = 0.008). A total of 446 (81.1%) diagnoses were made with high confidence. High confidence diagnoses corresponded to a significantly higher mean accuracy than low confidence diagnoses (84.0% vs 64.3%, P = 0.008). A total of 319 (58.0%) images were evaluated as having excellent quality. Considering excellent quality images in conjunction with high confidence diagnosis, overall accuracy increased to 92.8%. CONCLUSION:After a single training session, endoscopists with varying levels of experience can already provide optical diagnosis with an accuracy of 84.0%.展开更多
There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great ...There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.展开更多
Objective This study aimed to compare the performance of standard-definition white-light endoscopy(SD-WL),high-definition white-light endoscopy(HD-WL),and high-definition narrow-band imaging(HD-NBI)in detecting colore...Objective This study aimed to compare the performance of standard-definition white-light endoscopy(SD-WL),high-definition white-light endoscopy(HD-WL),and high-definition narrow-band imaging(HD-NBI)in detecting colorectal lesions in the Chinese population.Methods This was a multicenter,single-blind,randomized,controlled trial with a non-inferiority design.Patients undergoing endoscopy for physical examination,screening,and surveillance were enrolled from July 2017 to December 2020.The primary outcome measure was the adenoma detection rate(ADR),defined as the proportion of patients with at least one adenoma detected.The associated factors for detecting adenomas were assessed using univariate and multivariate logistic regression.Results Out of 653 eligible patients enrolled,data from 596 patients were analyzed.The ADRs were 34.5%in the SD-WL group,33.5%in the HD-WL group,and 37.5%in the HD-NBI group(P=0.72).The advanced neoplasm detection rates(ANDRs)in the three arms were 17.1%,15.5%,and 10.4%(P=0.17).No significant differences were found between the SD group and HD group regarding ADR or ANDR(ADR:34.5%vs.35.6%,P=0.79;ANDR:17.1%vs.13.0%,P=0.16,respectively).Similar results were observed between the HD-WL group and HD-NBI group(ADR:33.5%vs.37.7%,P=0.45;ANDR:15.5%vs.10.4%,P=0.18,respectively).In the univariate and multivariate logistic regression analyses,neither HD-WL nor HD-NBI led to a significant difference in overall adenoma detection compared to SD-WL(HD-WL:OR 0.91,P=0.69;HD-NBI:OR 1.15,P=0.80).Conclusion HD-NBI and HD-WL are comparable to SD-WL for overall adenoma detection among Chinese outpatients.It can be concluded that HD-NBI or HD-WL is not superior to SD-WL,but more effective instruction may be needed to guide the selection of different endoscopic methods in the future.Our study’s conclusions may aid in the efficient allocation and utilization of limited colonoscopy resources,especially advanced imaging technologies.展开更多
Background Cor pulmonale is often associated with changes of structure and function of the right ventricle (RV) and thus further affects functional changes of the left heart.Our study aimed to assess the left ventri...Background Cor pulmonale is often associated with changes of structure and function of the right ventricle (RV) and thus further affects functional changes of the left heart.Our study aimed to assess the left ventricular (LV) and RV function in patients with cor pulmonale using high-definition CT (HDCT).Methods We prospectively studied 18 cor pulmonale patients determined by the pulmonary function test,clinical examination,chest radiograph,electrocardiogram,and echocardiogram.The subject group was compared to a control group consisting of 18 subjects.The RV and LV functions and RV myocardial mass (MM) were obtained by HDCT in the two groups.The results were compared between the two groups using the independent sample t test.Echocardiographic examination for cardiac function analysis was performed on the same day.Results The RV end-diastolic volume (EDV),RV end-systolic volume (ESV) and RV myocardial mass were significantly larger in the 18 cor pulmonale patients than in the control group (P〈0.05).The right ventricular ejection fraction (RVEF) was significantly lower in the 18 cor pulmonale patients than in controls (P〈0.01).The left ventricular EDV (LVEDV) and LVEF were significantly lower in cor pulmonale patients than in controls (P〈0.01).There were strong correlations between MDCT and echocardiography,rRVEF=0.839 and rLVEF=0.916,respectively.Conclusions HDCT can accurately quantify RV and LV function.The right ventricular function is impaired in patients with cor pulmonale,while at the same time the left ventricular function is also impaired.展开更多
High-definition(HD)maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems.A complete ground orthophoto is usually used as the base image ...High-definition(HD)maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems.A complete ground orthophoto is usually used as the base image to construct the HD map.The ground orthophoto is obtained through inverse perspective transformation and image mosaicing.During the image mosaicing,multiple consecutive orthophotos are stitched together using pose information and image registration.In this study,wavelet transform is introduced to the image mosaicing process to alleviate the information loss caused by image overlapping.In the orthophoto wavelet transform,high-frequency and low-frequency components are fused using different strategies to form a complete base image with clearer local details.Experimental results show that the accuracy of the orthophotos generated using this method is improved.展开更多
Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies...Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.展开更多
A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and contr...A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and control, and traffic accident evaluation and prevention. Mapping an HD intersection is time-consuming, labor-intensive, and expensive with conventional methods. In this paper, we used a low-channel roadside light detection and range sensor(LiDAR) to automatically and dynamically generate a lane-level intersection, including the signal phases, geometry, layout, and lane directions. First, a mathematical model was proposed to describe the topology and detail of a lane-level intersection. Second, continuous and discontinuous traffic object trajectories were extracted to identify the signal phases and times. Third, the layout, geometry, and lane direction were identified using the convex hull detection algorithm for trajectories. Fourth, a sliding window algorithm was presented to detect the lane marking and extract the lane, and the virtual lane connecting the inbound and outbound of the intersection were generated using the vehicle trajectories within the intersection and considering the traffic rules. In the field experiment, the mean absolute estimation error is 2 s for signal phase and time identification. The lane marking identification Precision and Recall are96% and 94.12%, respectively. Compared with the satellite-based,MMS-based, and crowdsourcing-based lane mapping methods,the average lane location deviation is 0.2 m and the update period is less than one hour by the proposed method with low-channel roadside LiDAR.展开更多
CASEarth satellite is the first space Earth science satellite produced by the Chinese Academy of Sciences.The satellite has three payloads:high-definition Thermal Infrared Spectrometer(TIS),highdefinition Glimmer Imag...CASEarth satellite is the first space Earth science satellite produced by the Chinese Academy of Sciences.The satellite has three payloads:high-definition Thermal Infrared Spectrometer(TIS),highdefinition Glimmer Imager for Urbanization(GIU),and high-definition Multispectral Imager for Inshore(MII).These payloads are used to explore the urbanization level and residential layout,the coastal ecosystem,and new methods and approaches of environmental detection during night-time and even under conditions of polar aurora and provide scientific evidence for the refined depiction of human traces.The CASEarth satellite can provide space observation data for A Project on Big Earth Data Science Engineering as well as scientific and application studies inside and outside China.展开更多
The complex composition of herbal metabolites necessitates the development of powerful analytical techniques aimed to identify the bioactive components.The seeds of Descurainia sophia(SDS)are utilized in China as a co...The complex composition of herbal metabolites necessitates the development of powerful analytical techniques aimed to identify the bioactive components.The seeds of Descurainia sophia(SDS)are utilized in China as a cough and asthma relieving agent.Herein,a dimension-enhanced integral approach,by combining ultra-high performance liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(UHPLC/IMQTOF-MS)and intelligent peak annotation,was developed to rapidly characterize the multicomponents from SDS.Good chromatographic separation was achieved within 38 min on a UPLC CSH C18(2.1×100 mm,1.7μm)column which was eluted by 0.1%formic acid in water(water phase)and acetonitrile(organic phase).Collision-induced dissociation-MS^(2)data were acquired by the data-independent high-definition MS^(E)(HDMS^(E))in both the negative and positive electrospray ionization modes.A major components knockout strategy was applied to improve the characterization of those minor ingredients by enhancing the injection volume.Moreover,a self-built chemistry library was established,which could be matched by the UNIFI software enabling automatic peak annotation of the obtained HDMS^(E)data.As a result of applying the intelligent peak annotation workflows and further confirmation process,a total of 53 compounds were identified or tentatively characterized from the SDS,including 29 flavonoids,one uridine derivative,four glucosides,one lignin,one phenolic compound,and 17 others.Notably,four-dimensional information related to the structure(e.g.,retention time,collision cross section,MS^(1)and MS^(2)data)was obtained for each component by the developed integral approach,and the results would greatly benefit the quality control of SDS.展开更多
Objective This study aimed to assess the feasibility and usefulness of transabdominal color Doppler flow imaging(CDFI)technology and the high-definition flow imaging(HDFI)technique in detecting fetal pulmonary veins(P...Objective This study aimed to assess the feasibility and usefulness of transabdominal color Doppler flow imaging(CDFI)technology and the high-definition flow imaging(HDFI)technique in detecting fetal pulmonary veins(PVs)in the first trimester(11–13^(+6)weeks).Methods From December 2018 to October 2019,328 pregnant women with 328 normal singleton fetuses(crown-rump length:45–84 mm)who had undergone CDFI and HDFI scans for fetal heart and vessel examination were enrolled in this study.The cases were divided into three groups according to the gestational age:group A,11^(+0)−11^(+6)weeks;group B,12^(+0)−12^(+6)weeks;and group C,13^(+0)−13^(+6)weeks.Baseline sonograms and CDFI and HDFI images were analyzed by two senior radiologists independently and blindly.The abilities of CDFI and HDFI to display PVs were compared.Results Successful PV display rates via CDFI and HDFI were 2.3%and 68.2%(P<0.01),22.4%and 82.4%(P<0.01),41.5%and 91.2%(P<0.01)for group A,group B,and group C,respectively.The total successful display rates for the two methods were 28.9%(CDFI)and 84.8%(HDFI)(P<0.01).Conclusions The HDFI technique is more valuable than CDFI for detecting PVs in early pregnancy(11–13^(+6)weeks).HDFI can detect at least one PV in all cases and may be used to detect pulmonary venous anomalies early.展开更多
Lane detection is essential for many aspects of autonomous driving,such as lane-based navigation and high-definition(HD)map modeling.Although lane detection is challenging especially with complex road conditions,consi...Lane detection is essential for many aspects of autonomous driving,such as lane-based navigation and high-definition(HD)map modeling.Although lane detection is challenging especially with complex road conditions,considerable progress has been witnessed in this area in the past several years.In this survey,we review recent visual-based lane detection datasets and methods.For datasets,we categorize them by annotations,provide detailed descriptions for each category,and show comparisons among them.For methods,we focus on methods based on deep learning and organize them in terms of their detection targets.Moreover,we introduce a new dataset with more detailed annotations for HD map modeling,a new direction for lane detection that is applicable to autonomous driving in complex road conditions,a deep neural network LineNet for lane detection,and show its application to HD map modeling.展开更多
Objective:Zuogui Wan(ZGW)has been used as a typical prescription for tonifying kidney essence in traditional Chinese medicine.The objective of this study is to elucidate the phytochemical constituents of ZGW-treated r...Objective:Zuogui Wan(ZGW)has been used as a typical prescription for tonifying kidney essence in traditional Chinese medicine.The objective of this study is to elucidate the phytochemical constituents of ZGW-treated rat serum(ZGWRS)using ultra-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight high-definition mass spectrometry(UPLC-ESI-Q-TOF-MS).Methods:ZGW was administered to rats,and the phytochemical constituents in rat serum were determined using UPLC-ESI-Q-TOF-MS.MetaboLynx analysis in negative ion mode was adopted to characterize the chemical constituents of ZGWRS.Orthogonal partial least squares discriminant analysis was applied for the discovery of constituents of ZGW that entered the serum of rats.The fertilized eggs collected from the same experiment were randomly divided into four groups,including the normal,40 mmol/L glucose,40 mmol/L glucose 5%control rat serum,and 40 mmol/L glucose 5%ZGWRS groups.They were cultivated at 37°C and 5%CO2 in a saturated humidity CO2 incubator.The blastocyst rate and two-cell rate were used to evaluate the effects of ZGWRS on embryonic development.Results:Thirteen constituents were identified in the ZGWRS,among which sweroside,loganin,morroniside,loganic acid,and 8-epiloganic acid were from Fructus Corni(Shan Zhu Yu).5-Hydroxymethyl-2-furfural-glucuronide,2-H-5-hydroxymethyl-2-furfural-glucuronide,3-hydroxy-2,6,6-trimethyl-1-cyclohexene-1-carboxylic acid,andβ-D-ribofuranuronic acid methyl ester triacetate were from Radix Rehmanniae Preparata(Shu Di Huang).Coumaric acid was from Fructus Lycii(Gou Qi Zi).Kaempferol-3-beta-O-glucuronide and cuscutamine were from Semen Cuscutae(Tu Si Zi).The embryonic development was significantly inhibited using 40 mmol/L glucose.Compared with the normal group,the blastocyst rate of the glucose group was decreased.The blastocyst rate of the 40 mmol/L glucose 5%ZGWRS group was significantly higher than that of the glucose group,indicating that ZGWRS negates the effect of glucose on mouse embryonic development.Conclusion:The results verified that a rapid and robust UPLC-ESI-Q-TOF-MS-based platform had been successful for identifying multiple constituents of ZGW.ZGWRS is rich in active constituents of iridoid glycosides.The results of this study also showed that ZGWRS could negate the effect of glucose on mouse embryonic development.展开更多
This paper presents a hardware efficient high definition television (HDTV) encoder for H.264/AVC. We use a two-level mode decision (MD) mechanism to reduce the complexity and maintain the performance, and design a sha...This paper presents a hardware efficient high definition television (HDTV) encoder for H.264/AVC. We use a two-level mode decision (MD) mechanism to reduce the complexity and maintain the performance, and design a sharable architecture for normal mode fractional motion estimation (NFME), special mode fractional motion estimation (SFME), and luma motion compensation (LMC), to decrease the hardware cost. Based on these technologies, we adopt a four-stage macro-block pipeline scheme using an efficient memory management strategy for the system, which greatly reduces on-chip memory and bandwidth requirements. The proposed encoder uses about 1126k gates with an average Bjontegaard-Delta peak signal-to-noise ratio (BD-PSNR) decrease of 0.5 dB, compared with JM15.0. It can fully satisfy the real-time video encoding for 1080p@30 frames/s of H.264/AVC high profile.展开更多
文摘AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still images, comprising twin pictures (surface enhancement and tone enhancement), collected at our university hospital. We defined endoscopic features of adenomatous and non-adenomatous polyps, according to the following parameters:color, surface pattern and vascular pattern. We familiarized the participating endoscopists on optical diagnosis of colorectal polyps using a 20-min didactic training session. All endoscopists were asked to evaluate an image set of 50 colorectal polyps with regard to polyp histology. We classified the diagnoses into high confidence (i.e., cases in which the endoscopist could assign a diagnosis with certainty) and low confidence diagnoses (i.e., cases in which the endoscopist preferred to send the polyp for formal histology). Mean sensitivity, specificity and accuracy per endoscopist/image were computed and differences between groups tested using independent-samples t tests. High vs low confidence diagnoses were compared using the pairedsamples t test. RESULTS:Eleven endoscopists without previous experience on optical diagnosis evaluated a total of 550 images (396 adenomatous, 154 non-adenomatous). Mean sensitivity, specificity and accuracy for diagnosing adenomas were 79.3%, 85.7% and 81.1%, respectively. No significant differences were found between gastroenterologists and trainees regarding performances of optical diagnosis (mean accuracy 78.0%vs 82.9%,P = 0.098). Diminutive lesions were predicted with a lower mean accuracy as compared to non-diminutive lesions (74.2% vs 93.1%, P = 0.008). A total of 446 (81.1%) diagnoses were made with high confidence. High confidence diagnoses corresponded to a significantly higher mean accuracy than low confidence diagnoses (84.0% vs 64.3%, P = 0.008). A total of 319 (58.0%) images were evaluated as having excellent quality. Considering excellent quality images in conjunction with high confidence diagnosis, overall accuracy increased to 92.8%. CONCLUSION:After a single training session, endoscopists with varying levels of experience can already provide optical diagnosis with an accuracy of 84.0%.
文摘There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.
基金supported by the Beijing Municipal Science and Technology Commission(BMSTC,No.D171100002617001).
文摘Objective This study aimed to compare the performance of standard-definition white-light endoscopy(SD-WL),high-definition white-light endoscopy(HD-WL),and high-definition narrow-band imaging(HD-NBI)in detecting colorectal lesions in the Chinese population.Methods This was a multicenter,single-blind,randomized,controlled trial with a non-inferiority design.Patients undergoing endoscopy for physical examination,screening,and surveillance were enrolled from July 2017 to December 2020.The primary outcome measure was the adenoma detection rate(ADR),defined as the proportion of patients with at least one adenoma detected.The associated factors for detecting adenomas were assessed using univariate and multivariate logistic regression.Results Out of 653 eligible patients enrolled,data from 596 patients were analyzed.The ADRs were 34.5%in the SD-WL group,33.5%in the HD-WL group,and 37.5%in the HD-NBI group(P=0.72).The advanced neoplasm detection rates(ANDRs)in the three arms were 17.1%,15.5%,and 10.4%(P=0.17).No significant differences were found between the SD group and HD group regarding ADR or ANDR(ADR:34.5%vs.35.6%,P=0.79;ANDR:17.1%vs.13.0%,P=0.16,respectively).Similar results were observed between the HD-WL group and HD-NBI group(ADR:33.5%vs.37.7%,P=0.45;ANDR:15.5%vs.10.4%,P=0.18,respectively).In the univariate and multivariate logistic regression analyses,neither HD-WL nor HD-NBI led to a significant difference in overall adenoma detection compared to SD-WL(HD-WL:OR 0.91,P=0.69;HD-NBI:OR 1.15,P=0.80).Conclusion HD-NBI and HD-WL are comparable to SD-WL for overall adenoma detection among Chinese outpatients.It can be concluded that HD-NBI or HD-WL is not superior to SD-WL,but more effective instruction may be needed to guide the selection of different endoscopic methods in the future.Our study’s conclusions may aid in the efficient allocation and utilization of limited colonoscopy resources,especially advanced imaging technologies.
文摘Background Cor pulmonale is often associated with changes of structure and function of the right ventricle (RV) and thus further affects functional changes of the left heart.Our study aimed to assess the left ventricular (LV) and RV function in patients with cor pulmonale using high-definition CT (HDCT).Methods We prospectively studied 18 cor pulmonale patients determined by the pulmonary function test,clinical examination,chest radiograph,electrocardiogram,and echocardiogram.The subject group was compared to a control group consisting of 18 subjects.The RV and LV functions and RV myocardial mass (MM) were obtained by HDCT in the two groups.The results were compared between the two groups using the independent sample t test.Echocardiographic examination for cardiac function analysis was performed on the same day.Results The RV end-diastolic volume (EDV),RV end-systolic volume (ESV) and RV myocardial mass were significantly larger in the 18 cor pulmonale patients than in the control group (P〈0.05).The right ventricular ejection fraction (RVEF) was significantly lower in the 18 cor pulmonale patients than in controls (P〈0.01).The left ventricular EDV (LVEDV) and LVEF were significantly lower in cor pulmonale patients than in controls (P〈0.01).There were strong correlations between MDCT and echocardiography,rRVEF=0.839 and rLVEF=0.916,respectively.Conclusions HDCT can accurately quantify RV and LV function.The right ventricular function is impaired in patients with cor pulmonale,while at the same time the left ventricular function is also impaired.
基金the National Natural Science Foundation of China(No.U1764264/61873165)the Shanghai Automotive Industry Science and Technology Development Foundation(No.1807)the Guangxi Key Laboratory of Automobile Components and Vehicle Technology Research Project(No.2020GKLACVTKF02)。
文摘High-definition(HD)maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems.A complete ground orthophoto is usually used as the base image to construct the HD map.The ground orthophoto is obtained through inverse perspective transformation and image mosaicing.During the image mosaicing,multiple consecutive orthophotos are stitched together using pose information and image registration.In this study,wavelet transform is introduced to the image mosaicing process to alleviate the information loss caused by image overlapping.In the orthophoto wavelet transform,high-frequency and low-frequency components are fused using different strategies to form a complete base image with clearer local details.Experimental results show that the accuracy of the orthophotos generated using this method is improved.
文摘Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.
基金supported in part by the Scientific Research Project of the Education Department of Jilin Province (JJKH20221020KJ)the National Natural Science Foundation of China (51408257)the Graduate Innovation Fund of Jilin University (101832020CX150)。
文摘A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and control, and traffic accident evaluation and prevention. Mapping an HD intersection is time-consuming, labor-intensive, and expensive with conventional methods. In this paper, we used a low-channel roadside light detection and range sensor(LiDAR) to automatically and dynamically generate a lane-level intersection, including the signal phases, geometry, layout, and lane directions. First, a mathematical model was proposed to describe the topology and detail of a lane-level intersection. Second, continuous and discontinuous traffic object trajectories were extracted to identify the signal phases and times. Third, the layout, geometry, and lane direction were identified using the convex hull detection algorithm for trajectories. Fourth, a sliding window algorithm was presented to detect the lane marking and extract the lane, and the virtual lane connecting the inbound and outbound of the intersection were generated using the vehicle trajectories within the intersection and considering the traffic rules. In the field experiment, the mean absolute estimation error is 2 s for signal phase and time identification. The lane marking identification Precision and Recall are96% and 94.12%, respectively. Compared with the satellite-based,MMS-based, and crowdsourcing-based lane mapping methods,the average lane location deviation is 0.2 m and the update period is less than one hour by the proposed method with low-channel roadside LiDAR.
基金Supported by Chinese Academy of Sciences Strategic Leading Science and Technology Project(XDA19010000)。
文摘CASEarth satellite is the first space Earth science satellite produced by the Chinese Academy of Sciences.The satellite has three payloads:high-definition Thermal Infrared Spectrometer(TIS),highdefinition Glimmer Imager for Urbanization(GIU),and high-definition Multispectral Imager for Inshore(MII).These payloads are used to explore the urbanization level and residential layout,the coastal ecosystem,and new methods and approaches of environmental detection during night-time and even under conditions of polar aurora and provide scientific evidence for the refined depiction of human traces.The CASEarth satellite can provide space observation data for A Project on Big Earth Data Science Engineering as well as scientific and application studies inside and outside China.
基金This work was financially supported by the National Key Research and Development Program of China(Grant No.2018YFC1704500)Tianjin Committee of Science and Technology of China(Grant No.21ZYJDJC00080)National Natural Science Foundation of China(Grant No.81872996).
文摘The complex composition of herbal metabolites necessitates the development of powerful analytical techniques aimed to identify the bioactive components.The seeds of Descurainia sophia(SDS)are utilized in China as a cough and asthma relieving agent.Herein,a dimension-enhanced integral approach,by combining ultra-high performance liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(UHPLC/IMQTOF-MS)and intelligent peak annotation,was developed to rapidly characterize the multicomponents from SDS.Good chromatographic separation was achieved within 38 min on a UPLC CSH C18(2.1×100 mm,1.7μm)column which was eluted by 0.1%formic acid in water(water phase)and acetonitrile(organic phase).Collision-induced dissociation-MS^(2)data were acquired by the data-independent high-definition MS^(E)(HDMS^(E))in both the negative and positive electrospray ionization modes.A major components knockout strategy was applied to improve the characterization of those minor ingredients by enhancing the injection volume.Moreover,a self-built chemistry library was established,which could be matched by the UNIFI software enabling automatic peak annotation of the obtained HDMS^(E)data.As a result of applying the intelligent peak annotation workflows and further confirmation process,a total of 53 compounds were identified or tentatively characterized from the SDS,including 29 flavonoids,one uridine derivative,four glucosides,one lignin,one phenolic compound,and 17 others.Notably,four-dimensional information related to the structure(e.g.,retention time,collision cross section,MS^(1)and MS^(2)data)was obtained for each component by the developed integral approach,and the results would greatly benefit the quality control of SDS.
基金the Clinical Research Foundation of the Seventh Affiliated Hospital of Sun Yat-sen University(No.ZSQYLCKYJJ202010)the General Program of Science and Technology Project of Shenzhen(No.JCYJ20190814170205768)the Foundation of the Key Program of Social Science and Technology Development Project of Dongguan(No.202050715041216).
文摘Objective This study aimed to assess the feasibility and usefulness of transabdominal color Doppler flow imaging(CDFI)technology and the high-definition flow imaging(HDFI)technique in detecting fetal pulmonary veins(PVs)in the first trimester(11–13^(+6)weeks).Methods From December 2018 to October 2019,328 pregnant women with 328 normal singleton fetuses(crown-rump length:45–84 mm)who had undergone CDFI and HDFI scans for fetal heart and vessel examination were enrolled in this study.The cases were divided into three groups according to the gestational age:group A,11^(+0)−11^(+6)weeks;group B,12^(+0)−12^(+6)weeks;and group C,13^(+0)−13^(+6)weeks.Baseline sonograms and CDFI and HDFI images were analyzed by two senior radiologists independently and blindly.The abilities of CDFI and HDFI to display PVs were compared.Results Successful PV display rates via CDFI and HDFI were 2.3%and 68.2%(P<0.01),22.4%and 82.4%(P<0.01),41.5%and 91.2%(P<0.01)for group A,group B,and group C,respectively.The total successful display rates for the two methods were 28.9%(CDFI)and 84.8%(HDFI)(P<0.01).Conclusions The HDFI technique is more valuable than CDFI for detecting PVs in early pregnancy(11–13^(+6)weeks).HDFI can detect at least one PV in all cases and may be used to detect pulmonary venous anomalies early.
基金This work was supported by the National Natural Science Foundation of China under Grant Nos.61902210 and 61521002a research grant from the Beijing Higher Institution Engineering Research Center,and the Tsinghua-Tencent Joint Laboratory for Internet Innovation Technology.
文摘Lane detection is essential for many aspects of autonomous driving,such as lane-based navigation and high-definition(HD)map modeling.Although lane detection is challenging especially with complex road conditions,considerable progress has been witnessed in this area in the past several years.In this survey,we review recent visual-based lane detection datasets and methods.For datasets,we categorize them by annotations,provide detailed descriptions for each category,and show comparisons among them.For methods,we focus on methods based on deep learning and organize them in terms of their detection targets.Moreover,we introduce a new dataset with more detailed annotations for HD map modeling,a new direction for lane detection that is applicable to autonomous driving in complex road conditions,a deep neural network LineNet for lane detection,and show its application to HD map modeling.
基金financially supported by the Shanxi Province Science Foundation for the National International Cooperation(201703D421031)Youth Fund of the National Natural Science Fund project(81903951)TCM discipline construction project of SXTCM(Direction 3)(1008Z3)。
文摘Objective:Zuogui Wan(ZGW)has been used as a typical prescription for tonifying kidney essence in traditional Chinese medicine.The objective of this study is to elucidate the phytochemical constituents of ZGW-treated rat serum(ZGWRS)using ultra-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight high-definition mass spectrometry(UPLC-ESI-Q-TOF-MS).Methods:ZGW was administered to rats,and the phytochemical constituents in rat serum were determined using UPLC-ESI-Q-TOF-MS.MetaboLynx analysis in negative ion mode was adopted to characterize the chemical constituents of ZGWRS.Orthogonal partial least squares discriminant analysis was applied for the discovery of constituents of ZGW that entered the serum of rats.The fertilized eggs collected from the same experiment were randomly divided into four groups,including the normal,40 mmol/L glucose,40 mmol/L glucose 5%control rat serum,and 40 mmol/L glucose 5%ZGWRS groups.They were cultivated at 37°C and 5%CO2 in a saturated humidity CO2 incubator.The blastocyst rate and two-cell rate were used to evaluate the effects of ZGWRS on embryonic development.Results:Thirteen constituents were identified in the ZGWRS,among which sweroside,loganin,morroniside,loganic acid,and 8-epiloganic acid were from Fructus Corni(Shan Zhu Yu).5-Hydroxymethyl-2-furfural-glucuronide,2-H-5-hydroxymethyl-2-furfural-glucuronide,3-hydroxy-2,6,6-trimethyl-1-cyclohexene-1-carboxylic acid,andβ-D-ribofuranuronic acid methyl ester triacetate were from Radix Rehmanniae Preparata(Shu Di Huang).Coumaric acid was from Fructus Lycii(Gou Qi Zi).Kaempferol-3-beta-O-glucuronide and cuscutamine were from Semen Cuscutae(Tu Si Zi).The embryonic development was significantly inhibited using 40 mmol/L glucose.Compared with the normal group,the blastocyst rate of the glucose group was decreased.The blastocyst rate of the 40 mmol/L glucose 5%ZGWRS group was significantly higher than that of the glucose group,indicating that ZGWRS negates the effect of glucose on mouse embryonic development.Conclusion:The results verified that a rapid and robust UPLC-ESI-Q-TOF-MS-based platform had been successful for identifying multiple constituents of ZGW.ZGWRS is rich in active constituents of iridoid glycosides.The results of this study also showed that ZGWRS could negate the effect of glucose on mouse embryonic development.
基金supported by the National Natural Science Foundation of China (No. 61076021)the Program for New Century Excellent Talents in Universities, China
文摘This paper presents a hardware efficient high definition television (HDTV) encoder for H.264/AVC. We use a two-level mode decision (MD) mechanism to reduce the complexity and maintain the performance, and design a sharable architecture for normal mode fractional motion estimation (NFME), special mode fractional motion estimation (SFME), and luma motion compensation (LMC), to decrease the hardware cost. Based on these technologies, we adopt a four-stage macro-block pipeline scheme using an efficient memory management strategy for the system, which greatly reduces on-chip memory and bandwidth requirements. The proposed encoder uses about 1126k gates with an average Bjontegaard-Delta peak signal-to-noise ratio (BD-PSNR) decrease of 0.5 dB, compared with JM15.0. It can fully satisfy the real-time video encoding for 1080p@30 frames/s of H.264/AVC high profile.