Weather forecasts from numerical weather prediction models play a central role in solar energy forecasting,where a cascade of physics-based models is used in a model chain approach to convert forecasts of solar irradi...Weather forecasts from numerical weather prediction models play a central role in solar energy forecasting,where a cascade of physics-based models is used in a model chain approach to convert forecasts of solar irradiance to solar power production.Ensemble simulations from such weather models aim to quantify uncertainty in the future development of the weather,and can be used to propagate this uncertainty through the model chain to generate probabilistic solar energy predictions.However,ensemble prediction systems are known to exhibit systematic errors,and thus require post-processing to obtain accurate and reliable probabilistic forecasts.The overarching aim of our study is to systematically evaluate different strategies to apply post-processing in model chain approaches with a specific focus on solar energy:not applying any post-processing at all;post-processing only the irradiance predictions before the conversion;post-processing only the solar power predictions obtained from the model chain;or applying post-processing in both steps.In a case study based on a benchmark dataset for the Jacumba solar plant in the U.S.,we develop statistical and machine learning methods for postprocessing ensemble predictions of global horizontal irradiance(GHI)and solar power generation.Further,we propose a neural-network-based model for direct solar power forecasting that bypasses the model chain.Our results indicate that postprocessing substantially improves the solar power generation forecasts,in particular when post-processing is applied to the power predictions.The machine learning methods for post-processing slightly outperform the statistical methods,and the direct forecasting approach performs comparably to the post-processing strategies.展开更多
AIM:To investigate the effects of chronic alcohol consumption on retinal microcirculation by comparing different alcohol-consuming groups using optical coherence tomography(OCT)and OCT angiography(OCTA).METHODS:This o...AIM:To investigate the effects of chronic alcohol consumption on retinal microcirculation by comparing different alcohol-consuming groups using optical coherence tomography(OCT)and OCT angiography(OCTA).METHODS:This observational clinical study utilized a cross-sectional and prospective design,focusing on chronic alcohol consumers alongside a non-consuming control group.OCT/OCTA imaging parameters including central retinal subfield thickness(CST),subfoveal choroidal thickness(SCT),foveal avascular zone(FAZ)and vessel density(VD)in the superficial and deep capillary plexuses in both the macular and optic disc(OD)regions were recorded.Data were analyzed using SPSS 15.0;descriptive statistics were reported,group comparisons were performed with Chisquare,Kruskal–Wallis,and Bonferroni-corrected Mann–Whitney U tests,and relationships were assessed using Spearman correlation,with statistical significance set at P<0.05.RESULTS:A total of 160 eyes of 160 participants(110 females and 50 males with mean age 38.7±9.9y)who don’t smoke were divided into five groups:never,occasional,monthly,weekly and daily drinkers.The mean CST was 216.6±14.2μm and the mean SCT was 358.9±84.5μm.There was no statistically significantly difference in CST and SCT among the groups(P=0.890,0.799).Foveal superficial capillary plexuses(SCPs)VD was higher in monthly drinkers compared to occasional drinkers(P=0.015).Foveal VD in deep capillary plexus was also higher in monthly drinkers than in never and occasional drinkers(P=0.004,0.006).Nasal SCPs VD at the OD was higher in monthly drinkers compared to never drinkers(P=0.005).There was no significant difference FAZ area among the groups(P=0.071).CONCLUSION:Both superficial and deep microvascular structures in the inferior quadrants of macula are positively correlated with frequency of alcohol use.Also in our study results is that the monthly drinker group has uniquely higher VDs in both macula and OD.This leads us to consider moderate alcohol consumption may also have protective effects on retinal microcirculation.展开更多
In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow bas...In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow based on computational or experimental results. Field plots by contours, iso-surfaces, streamlines, vectors and others are traditional post-processing techniques. While the shock wave, as one important and critical flow structure in many aerodynamic problems, can hardly be detected or distinguished in a direct way using these traditional methods, due to possible confusions with other similar discontinuous flow structures like slip line, contact discontinuity, etc. Therefore, method for automatic detection of shock wave in post-processing is of great importance for both academic research and engineering applications. In this paper, the current status of methodologies developed for shock wave detection and implementations in post-processing platform are reviewed, as well as discussions on advantages and limitations of the existing methods and proposals for further studies of shock wave detection method. We also develop an advanced post-processing software, with improved shock detection.展开更多
Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve...Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors＇ responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32× 32 APD array is up to tens of Gbits/s.展开更多
In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflec...In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflect actual situations and facilitate their computation and analyses.Given the importance of model building, further processing methods about traditional seismic interpretation results from Landmark should be studied and the processed result can then be directly used in numerical simulation computations.Through this data conversion procedure, Landmark and FLAC(the international general stress software) are seamlessly connected.Thus, the format conversion between the two systems and the pre-and post-processing in simulation computation is realized.A practical application indicates that this method has many advantages such as simple operation, high accuracy of the element subdivision and high speed, which may definitely satisfy the actual needs of floor grid cutting.展开更多
The travel time data collection method is used to assist the congestion management. The use of traditional sensors (e.g. inductive loops, AVI sensors) or more recent Bluetooth sensors installed on major roads for coll...The travel time data collection method is used to assist the congestion management. The use of traditional sensors (e.g. inductive loops, AVI sensors) or more recent Bluetooth sensors installed on major roads for collecting data is not sufficient because of their limited coverage and expensive costs for installation and maintenance. Application of the Global Positioning Systems (GPS) in travel time and delay data collections is proven to be efficient in terms of accuracy, level of details for the data and required data collection of man-power. While data collection automation is improved by the GPS technique, human errors can easily find their way through the post-processing phase, and therefore data post-processing remains a challenge especially in case of big projects with high amount of data. This paper introduces a stand-alone post-processing tool called GPS Calculator, which provides an easy-to-use environment to carry out data post-processing. This is a Visual Basic application that processes the data files obtained in the field and integrates them into Geographic Information Systems (GIS) for analysis and representation. The results show that this tool obtains similar results to the currently used data post-processing method, reduces the post-processing effort, and also eliminates the need for the second person during the data collection.展开更多
When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive ...When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive numerical data may probably exceed the capacity of available memory,resulting in failure of rendering.Based on the out-of-core technique,this paper proposes a method to effectively utilize external storage and reduce memory usage dramatically,so as to solve the problem of insufficient memory for massive data rendering on general personal computers.Based on this method,a new postprocessor is developed.It is capable to illustrate filling and solidification processes of casting,as well as thermal stess.The new post-processor also provides fast interaction to simulation results.Theoretical analysis as well as several practical examples prove that the memory usage and loading time of the post-processor are independent of the size of the relevant files,but the proportion of the number of cells on surface.Meanwhile,the speed of rendering and fetching of value from the mouse is appreciable,and the demands of real-time and interaction are satisfied.展开更多
To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum...To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.展开更多
Background: Coronary artery disease is the most common form of cardiovascular disease while Atrial fibrillation is the most common sustained arrhythmia. We set out to investigate the prevalence and clinical profile of...Background: Coronary artery disease is the most common form of cardiovascular disease while Atrial fibrillation is the most common sustained arrhythmia. We set out to investigate the prevalence and clinical profile of patients with atrial fibrillation who present for selective coronary angiography and whether this has an effect on the angiogram findings and the treatment options offered to them. Methods and Results: This was a retrospectively collected database of 494 patients presenting for SCAG from 01.11.2010 to 30.11.2010 and 01.04.2010 to 30.04.2010. We collected and analyzed clinical characteristics of patients, their SCAG finding and modes of treatment offered up to discharge. 24.6% of patients had AF. They tended to be older, more commonly women, current or ex-smokers;presented with symptoms of atypical chest pain and were more likely to have a history of congestive heart failure or valvular heart disease. They had a longer hospital stay. Using CHADS-Vasc score, 83.6% were moderate to high risk for CVA. At SCAG, they were more likely to have non-significant coronary artery disease, and hence were more likely to be treated conservatively. Conclusion: AF patients presenting for SCAG constitute a unique subset of patients who despite having a higher likelihood of non-significant coronary stenosis are still prone to suffering from poorly-understood and under-appreciated myocardial ischemia.展开更多
This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids...This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids. The sinusoid which contributes most to the reduction of overall NMR is chosen. Combined with our improved parametric psychoacoustic model and advanced peak riddling techniques, the number of sinusoids required can be greatly reduced and the coding efficiency can be greatly enhanced. A lightweight version is also given to reduce the amount of computation with only little sacrifice of performance. Secondly, we propose two enhancement techniques for sinusoid synthesis: bandwidth enhancement and line enhancement. With little overhead, the effective bandwidth can be extended one more octave; the timbre tends to sound much brighter, thicker and more beautiful.展开更多
Low contrast of Magnetic Resonance(MR)images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis.State-of-the-art contrast boosting techniques intole...Low contrast of Magnetic Resonance(MR)images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis.State-of-the-art contrast boosting techniques intolerably alter inherent features of MR images.Drastic changes in brightness features,induced by post-processing are not appreciated in medical imaging as the grey level values have certain diagnostic meanings.To overcome these issues this paper proposes an algorithm that enhance the contrast of MR images while preserving the underlying features as well.This method termed as Power-law and Logarithmic Modification-based Histogram Equalization(PLMHE)partitions the histogram of the image into two sub histograms after a power-law transformation and a log compression.After a modification intended for improving the dispersion of the sub-histograms and subsequent normalization,cumulative histograms are computed.Enhanced grey level values are computed from the resultant cumulative histograms.The performance of the PLMHE algorithm is comparedwith traditional histogram equalization based algorithms and it has been observed from the results that PLMHE can boost the image contrast without causing dynamic range compression,a significant change in mean brightness,and contrast-overshoot.展开更多
In the analysis of high-rise building, traditional displacement-based plane elements are often used to get the in-plane internal forces of the shear walls by stress integration. Limited by the singular problem produce...In the analysis of high-rise building, traditional displacement-based plane elements are often used to get the in-plane internal forces of the shear walls by stress integration. Limited by the singular problem produced by wall holes and the loss of precision induced by using differential method to derive strains, the displacement-based elements cannot always present accuracy enough for design. In this paper, the hybrid post-processing procedure based on the Hellinger-Reissner variational principle is used for improving the stress precision of two quadrilateral plane elements. In order to find the best stress field, three different forms are assumed for the displacement-based plane elements and with drilling DOF. Numerical results show that by using the proposed method, the accuracy of stress solutions of these two displacement-based plane elements can be improved.展开更多
Laser additive manufacturing(LAM)of titanium(Ti)alloys has emerged as a transformative technology with vast potential across multiple industries.To recap the state of the art,Ti alloys processed by two essential LAM t...Laser additive manufacturing(LAM)of titanium(Ti)alloys has emerged as a transformative technology with vast potential across multiple industries.To recap the state of the art,Ti alloys processed by two essential LAM techniques(i.e.,laser powder bed fusion and laser-directed energy deposition)will be reviewed,covering the aspects of processes,materials and post-processing.The impacts of process parameters and strategies for optimizing parameters will be elucidated.Various types of Ti alloys processed by LAM,includingα-Ti,(α+β)-Ti,andβ-Ti alloys,will be overviewed in terms of micro structures and benchmarking properties.Furthermore,the post-processing methods for improving the performance of L AM-processed Ti alloys,including conventional and novel heat treatment,hot isostatic pressing,and surface processing(e.g.,ultrasonic and laser shot peening),will be systematically reviewed and discussed.The review summarizes the process windows,properties,and performance envelopes and benchmarks the research achievements in LAM of Ti alloys.The outlooks of further trends in LAM of Ti alloys are also highlighted at the end of the review.This comprehensive review could serve as a valuable resource for researchers and practitioners,promoting further advancements in LAM-built Ti alloys and their applications.展开更多
AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA scree...AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.展开更多
BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identifica...BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the haemorrhage.AIM To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic findings.METHODS In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were enrolled.Twenty-three(65.7%)patients underwent endoscopy before CTA.Bleeding volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated software.Bleeding rate was obtained from volume change between the two phases and standardised for unit time.Patients were divided into two groups,according to the angiographic signs and their concordance with CTA.RESULTS Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)cases.Despite no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.展开更多
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im...BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.展开更多
Background:Hemoptysis patients with bronchial artery-pulmonary artery fistula(BPF)have a high incidence of poor prog-nosis.This study aimed to evaluate the diagnostic performance of computed tomography angiography(CTA...Background:Hemoptysis patients with bronchial artery-pulmonary artery fistula(BPF)have a high incidence of poor prog-nosis.This study aimed to evaluate the diagnostic performance of computed tomography angiography(CTA)for detecting BPF in hemoptysis patients and to compare the clinical characteristics and computed tomography(CT)findings between patients with and without BPF.Methods:We retrospectively enrolled 201 consecutive patients with hemoptysis who underwent bronchial arterial emboli-zation in our hospital from January 2020 to November 2020.The clinical characteristics,preprocedural CT findings,and digital subtraction angiography(DSA)findings were recorded.Patients were categorized into BPF-positive and BPF-negative groups based on DSA results.The diagnostic accuracy of CTA for BPF detection was evaluated against that of DSA using receiver operating characteristic curve analysis.Differences in clinical and CT parameters between the two groups were assessed.Multivariate logistic regression analysis was used to discover the independent factors associated with the presence of BPF.Results:Among 201 patients with hemoptysis,DSA identified BPF in 75,while CTA identified BPF in 65.The diagnostic agreement between CTA and DSA for BPF detection was excellent(Kappa coefficient:κ=0.825,p<0.001).CTA demonstrated high sensitivity(0.827),specificity(0.976),and accuracy(0.920)for BPF detection.Multivariate logistic analysis identified the severity of pulmonary parenchymal lesion and bronchial artery tortuosity as independent predictors of BPF.Conclusions:Preprocedural CTA is a reliable examination to identify BPF in patients with hemoptysis.Pulmonary lesion severity and bronchial artery tortuosity are independent factors associated with the presence of BPF in patients with hemoptysis.展开更多
Objective To evaluate the prevalence and one-year prognosis associated with frailty in a contemporary cohort of older patients with non-ST-elevation acute coronary syndrome(NSTEACS).Methods The IMPACT-TIMING-GO regist...Objective To evaluate the prevalence and one-year prognosis associated with frailty in a contemporary cohort of older patients with non-ST-elevation acute coronary syndrome(NSTEACS).Methods The IMPACT-TIMING-GO registry(IMPACT of Time of Intervention in patients with Myocardial Infarction with Non-ST seGment elevation.ManaGement and Outcomes)prospectively included 1020 patients with NSTEACS undergoing invasive coronary angiography between April and May 2021.For this sub-study,patients≥65 years were selected.Frailty was assessed according to FRAIL scale.We studied all-cause mortality and the composite of all-cause mortality or all-cause hospitalizations at one-year follow-up after discharge.Results Five hundred and sixty seven patients(mean age:75.8±6.7 years,28.2%women)were included:316(55.7%)were robust,183(32.3%)prefrail,and 68(12.0%)frail.Frail patients were significantly older,more often women,and presented a worse baseline clinical profile.There were no differences among groups regarding pretreatment with a P2Y12 inhibitor.An urgent angiography(<24 h)was less frequently performed in frail patients,with no differences regarding revascularization approach or in main in-hospital adverse events,although acute kidney disease occurred more frequently in frail patients.At 1-year follow-up,20 patients died(3.6%).Chronic kidney disease was independently associated with 1-year all-cause death,although a trend towards higher mortality was observed in frail patients(HR=3.01;95%CI:0.93-9.78;P=0.065).Frailty was independently associated with higher 1-year all-cause mortality or all-cause rehospitalizations(HR=2.23;95%CI:1.43-3.46;P<0.001)Conclusions In older patients with NSTEACS,frailty independently associates higher all-cause mortality or all-cause hospital admissions at one-year follow-up.展开更多
Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hinder...Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hindered by the trade-off between transverse sampling rate and signal-to-noise ratio(SNR).This trade-off results in either a limited field of view(FOV)to maintain sampling density or loss of capillary details to fulfil FOV requirement.It also restricts microvascular quantifications,including flow velocimetry,which typically demand higher transverse sampling rate and SNR compared with standard qualitative OCTA.We introduce spectrally extended line field OCTA(SELF-OCTA),a cost-effective imag-ing modality that improves transverse sampling rate and SNR through spectrally encoded parallel sampling and in-creased signal acquired over longer periods,respectively.In the human skin and retina in vivo,we demonstrate its ad-vantages in achieving significantly extended FOV without sacrificing microvascular resolution,high sensitivity to slower flow without compromising FOV,and flow velocity quantification with the highest dynamic range,emphasizing that these features can be achieved with readily available and standard OCTA hardware settings.SELF-OCTA has the potential to make wide-field,high-resolution,quantitative angiographic imaging accessible to a wider population,thereby facilitating the early detection and follow-up of vascular-related diseases.展开更多
BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch a...BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch and central retinal arteries and veins,alongside anterior and posterior ischemic optic neuropathy.With the advent of optical coherence tomography angiography(OCTA),it is easy to identify these macular subclinical microvascular and structural changes.AIM To evaluate macular and peripapillary structural and microvasculature changes in patients with migraine with aura(MA),migraine without aura(MW),and healthy control(HC)participants using OCTA.METHODS In this observational cross-sectional study,we studied a total of 100 eyes:(1)32 eyes of 16 patients with MA;(2)36 eyes of 18 patients with MW,recruited based on the International Classification of Headache Disorders;and(3)32 eyes of 16 age and sex-matched healthy participants.Foveal flux,foveal avascular zone(FAZ),peripapillary flux obtained from OCTA,and foveal and peripapillary ganglion cell layer(GCL)thickness calculated via optical coherence tomography were compared among the groups.RESULTS The mean FAZ area measured in patients with MA and MW was significantly larger than that in the control participants(P=0.002).However,there was no significant difference between the FAZ of the MA and MW groups.Macular perfusion in the superficial capillary plexus in patients with MA was significantly lower compared to MW(P=0.0018)and HCs(P=0.002).There was also significant thinning of the GCL in patients with MA and MW(P=0.001)compared to HCs.However,there was no significant difference in temporal GCL thickness between the MA and MW groups.CONCLUSION Significant changes have been found in structural and microvascular parameters in patients with migraines compared with HCs.OCTA can serve as a valuable non-invasive imaging technique for identifying microcirculatory disturbances,aiding in better understanding the pathogenesis of different types of migraine and establishing their link with other ischemic retinal and systemic pathologies.展开更多
基金the Young Investigator Group“Artificial Intelligence for Probabilistic Weather Forecasting”funded by the Vector Stiftungfunding from the Federal Ministry of Education and Research(BMBF)and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments。
文摘Weather forecasts from numerical weather prediction models play a central role in solar energy forecasting,where a cascade of physics-based models is used in a model chain approach to convert forecasts of solar irradiance to solar power production.Ensemble simulations from such weather models aim to quantify uncertainty in the future development of the weather,and can be used to propagate this uncertainty through the model chain to generate probabilistic solar energy predictions.However,ensemble prediction systems are known to exhibit systematic errors,and thus require post-processing to obtain accurate and reliable probabilistic forecasts.The overarching aim of our study is to systematically evaluate different strategies to apply post-processing in model chain approaches with a specific focus on solar energy:not applying any post-processing at all;post-processing only the irradiance predictions before the conversion;post-processing only the solar power predictions obtained from the model chain;or applying post-processing in both steps.In a case study based on a benchmark dataset for the Jacumba solar plant in the U.S.,we develop statistical and machine learning methods for postprocessing ensemble predictions of global horizontal irradiance(GHI)and solar power generation.Further,we propose a neural-network-based model for direct solar power forecasting that bypasses the model chain.Our results indicate that postprocessing substantially improves the solar power generation forecasts,in particular when post-processing is applied to the power predictions.The machine learning methods for post-processing slightly outperform the statistical methods,and the direct forecasting approach performs comparably to the post-processing strategies.
文摘AIM:To investigate the effects of chronic alcohol consumption on retinal microcirculation by comparing different alcohol-consuming groups using optical coherence tomography(OCT)and OCT angiography(OCTA).METHODS:This observational clinical study utilized a cross-sectional and prospective design,focusing on chronic alcohol consumers alongside a non-consuming control group.OCT/OCTA imaging parameters including central retinal subfield thickness(CST),subfoveal choroidal thickness(SCT),foveal avascular zone(FAZ)and vessel density(VD)in the superficial and deep capillary plexuses in both the macular and optic disc(OD)regions were recorded.Data were analyzed using SPSS 15.0;descriptive statistics were reported,group comparisons were performed with Chisquare,Kruskal–Wallis,and Bonferroni-corrected Mann–Whitney U tests,and relationships were assessed using Spearman correlation,with statistical significance set at P<0.05.RESULTS:A total of 160 eyes of 160 participants(110 females and 50 males with mean age 38.7±9.9y)who don’t smoke were divided into five groups:never,occasional,monthly,weekly and daily drinkers.The mean CST was 216.6±14.2μm and the mean SCT was 358.9±84.5μm.There was no statistically significantly difference in CST and SCT among the groups(P=0.890,0.799).Foveal superficial capillary plexuses(SCPs)VD was higher in monthly drinkers compared to occasional drinkers(P=0.015).Foveal VD in deep capillary plexus was also higher in monthly drinkers than in never and occasional drinkers(P=0.004,0.006).Nasal SCPs VD at the OD was higher in monthly drinkers compared to never drinkers(P=0.005).There was no significant difference FAZ area among the groups(P=0.071).CONCLUSION:Both superficial and deep microvascular structures in the inferior quadrants of macula are positively correlated with frequency of alcohol use.Also in our study results is that the monthly drinker group has uniquely higher VDs in both macula and OD.This leads us to consider moderate alcohol consumption may also have protective effects on retinal microcirculation.
文摘In the present computational fluid dynamics （CFD） community, post-processing is regarded as a procedure to view parameter distribution, detect characteristic structure and reveal physical mechanism of fluid flow based on computational or experimental results. Field plots by contours, iso-surfaces, streamlines, vectors and others are traditional post-processing techniques. While the shock wave, as one important and critical flow structure in many aerodynamic problems, can hardly be detected or distinguished in a direct way using these traditional methods, due to possible confusions with other similar discontinuous flow structures like slip line, contact discontinuity, etc. Therefore, method for automatic detection of shock wave in post-processing is of great importance for both academic research and engineering applications. In this paper, the current status of methodologies developed for shock wave detection and implementations in post-processing platform are reviewed, as well as discussions on advantages and limitations of the existing methods and proposals for further studies of shock wave detection method. We also develop an advanced post-processing software, with improved shock detection.
基金Supported by the Chinese Academy of Sciences Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics,Shanghai Branch,University of Science and Technology of Chinathe National Natural Science Foundation of China under Grant No 11405172
文摘Quantum random number generators adopting single negligible dead time of avalanche photodiodes （APDs） photon detection have been restricted due to the non- We propose a new approach based on an APD array to improve the generation rate of random numbers significantly. This method compares the detectors＇ responses to consecutive optical pulses and generates the random sequence. We implement a demonstration experiment to show its simplicity, compactness and scalability. The generated numbers are proved to be unbiased, post-processing free, ready to use, and their randomness is verified by using the national institute of standard technology statistical test suite. The random bit generation efficiency is as high as 32.8% and the potential generation rate adopting the 32× 32 APD array is up to tens of Gbits/s.
基金Projects 50221402, 50490271 and 50025413 supported by the National Natural Science Foundation of Chinathe National Basic Research Program of China (2009CB219603, 2009 CB724601, 2006CB202209 and 2005CB221500)+1 种基金the Key Project of the Ministry of Education (306002)the Program for Changjiang Scholars and Innovative Research Teams in Universities of MOE (IRT0408)
文摘In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflect actual situations and facilitate their computation and analyses.Given the importance of model building, further processing methods about traditional seismic interpretation results from Landmark should be studied and the processed result can then be directly used in numerical simulation computations.Through this data conversion procedure, Landmark and FLAC(the international general stress software) are seamlessly connected.Thus, the format conversion between the two systems and the pre-and post-processing in simulation computation is realized.A practical application indicates that this method has many advantages such as simple operation, high accuracy of the element subdivision and high speed, which may definitely satisfy the actual needs of floor grid cutting.
文摘The travel time data collection method is used to assist the congestion management. The use of traditional sensors (e.g. inductive loops, AVI sensors) or more recent Bluetooth sensors installed on major roads for collecting data is not sufficient because of their limited coverage and expensive costs for installation and maintenance. Application of the Global Positioning Systems (GPS) in travel time and delay data collections is proven to be efficient in terms of accuracy, level of details for the data and required data collection of man-power. While data collection automation is improved by the GPS technique, human errors can easily find their way through the post-processing phase, and therefore data post-processing remains a challenge especially in case of big projects with high amount of data. This paper introduces a stand-alone post-processing tool called GPS Calculator, which provides an easy-to-use environment to carry out data post-processing. This is a Visual Basic application that processes the data files obtained in the field and integrates them into Geographic Information Systems (GIS) for analysis and representation. The results show that this tool obtains similar results to the currently used data post-processing method, reduces the post-processing effort, and also eliminates the need for the second person during the data collection.
基金supported by the New Century Excellent Talents in University(NCET-09-0396)the National Science&Technology Key Projects of Numerical Control(2012ZX04014-031)+1 种基金the Natural Science Foundation of Hubei Province(2011CDB279)the Foundation for Innovative Research Groups of the Natural Science Foundation of Hubei Province,China(2010CDA067)
文摘When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive numerical data may probably exceed the capacity of available memory,resulting in failure of rendering.Based on the out-of-core technique,this paper proposes a method to effectively utilize external storage and reduce memory usage dramatically,so as to solve the problem of insufficient memory for massive data rendering on general personal computers.Based on this method,a new postprocessor is developed.It is capable to illustrate filling and solidification processes of casting,as well as thermal stess.The new post-processor also provides fast interaction to simulation results.Theoretical analysis as well as several practical examples prove that the memory usage and loading time of the post-processor are independent of the size of the relevant files,but the proportion of the number of cells on surface.Meanwhile,the speed of rendering and fetching of value from the mouse is appreciable,and the demands of real-time and interaction are satisfied.
基金supported by the National Natural Science Foundation of China(51875535)the Natural Science Foundation for Young Scientists of Shanxi Province(201701D221017,201901D211242)。
文摘To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.
文摘Background: Coronary artery disease is the most common form of cardiovascular disease while Atrial fibrillation is the most common sustained arrhythmia. We set out to investigate the prevalence and clinical profile of patients with atrial fibrillation who present for selective coronary angiography and whether this has an effect on the angiogram findings and the treatment options offered to them. Methods and Results: This was a retrospectively collected database of 494 patients presenting for SCAG from 01.11.2010 to 30.11.2010 and 01.04.2010 to 30.04.2010. We collected and analyzed clinical characteristics of patients, their SCAG finding and modes of treatment offered up to discharge. 24.6% of patients had AF. They tended to be older, more commonly women, current or ex-smokers;presented with symptoms of atypical chest pain and were more likely to have a history of congestive heart failure or valvular heart disease. They had a longer hospital stay. Using CHADS-Vasc score, 83.6% were moderate to high risk for CVA. At SCAG, they were more likely to have non-significant coronary artery disease, and hence were more likely to be treated conservatively. Conclusion: AF patients presenting for SCAG constitute a unique subset of patients who despite having a higher likelihood of non-significant coronary stenosis are still prone to suffering from poorly-understood and under-appreciated myocardial ischemia.
文摘This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids. The sinusoid which contributes most to the reduction of overall NMR is chosen. Combined with our improved parametric psychoacoustic model and advanced peak riddling techniques, the number of sinusoids required can be greatly reduced and the coding efficiency can be greatly enhanced. A lightweight version is also given to reduce the amount of computation with only little sacrifice of performance. Secondly, we propose two enhancement techniques for sinusoid synthesis: bandwidth enhancement and line enhancement. With little overhead, the effective bandwidth can be extended one more octave; the timbre tends to sound much brighter, thicker and more beautiful.
基金This work was supported by Taif university Researchers Supporting Project Number(TURSP-2020/114),Taif University,Taif,Saudi Arabia.
文摘Low contrast of Magnetic Resonance(MR)images limits the visibility of subtle structures and adversely affects the outcome of both subjective and automated diagnosis.State-of-the-art contrast boosting techniques intolerably alter inherent features of MR images.Drastic changes in brightness features,induced by post-processing are not appreciated in medical imaging as the grey level values have certain diagnostic meanings.To overcome these issues this paper proposes an algorithm that enhance the contrast of MR images while preserving the underlying features as well.This method termed as Power-law and Logarithmic Modification-based Histogram Equalization(PLMHE)partitions the histogram of the image into two sub histograms after a power-law transformation and a log compression.After a modification intended for improving the dispersion of the sub-histograms and subsequent normalization,cumulative histograms are computed.Enhanced grey level values are computed from the resultant cumulative histograms.The performance of the PLMHE algorithm is comparedwith traditional histogram equalization based algorithms and it has been observed from the results that PLMHE can boost the image contrast without causing dynamic range compression,a significant change in mean brightness,and contrast-overshoot.
文摘In the analysis of high-rise building, traditional displacement-based plane elements are often used to get the in-plane internal forces of the shear walls by stress integration. Limited by the singular problem produced by wall holes and the loss of precision induced by using differential method to derive strains, the displacement-based elements cannot always present accuracy enough for design. In this paper, the hybrid post-processing procedure based on the Hellinger-Reissner variational principle is used for improving the stress precision of two quadrilateral plane elements. In order to find the best stress field, three different forms are assumed for the displacement-based plane elements and with drilling DOF. Numerical results show that by using the proposed method, the accuracy of stress solutions of these two displacement-based plane elements can be improved.
基金financially supported by the 2022 MTC Young Individual Research Grants under Singapore Research,Innovation and Enterprise(RIE)2025 Plan(No.M22K3c0097)the Natural Science Foundation of US(No.DMR-2104933)the sponsorship of the China Scholarship Council(No.202106130051)。
文摘Laser additive manufacturing(LAM)of titanium(Ti)alloys has emerged as a transformative technology with vast potential across multiple industries.To recap the state of the art,Ti alloys processed by two essential LAM techniques(i.e.,laser powder bed fusion and laser-directed energy deposition)will be reviewed,covering the aspects of processes,materials and post-processing.The impacts of process parameters and strategies for optimizing parameters will be elucidated.Various types of Ti alloys processed by LAM,includingα-Ti,(α+β)-Ti,andβ-Ti alloys,will be overviewed in terms of micro structures and benchmarking properties.Furthermore,the post-processing methods for improving the performance of L AM-processed Ti alloys,including conventional and novel heat treatment,hot isostatic pressing,and surface processing(e.g.,ultrasonic and laser shot peening),will be systematically reviewed and discussed.The review summarizes the process windows,properties,and performance envelopes and benchmarks the research achievements in LAM of Ti alloys.The outlooks of further trends in LAM of Ti alloys are also highlighted at the end of the review.This comprehensive review could serve as a valuable resource for researchers and practitioners,promoting further advancements in LAM-built Ti alloys and their applications.
文摘AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.
文摘BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the haemorrhage.AIM To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic findings.METHODS In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were enrolled.Twenty-three(65.7%)patients underwent endoscopy before CTA.Bleeding volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated software.Bleeding rate was obtained from volume change between the two phases and standardised for unit time.Patients were divided into two groups,according to the angiographic signs and their concordance with CTA.RESULTS Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)cases.Despite no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.
文摘BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.
基金supported by the Science and Technology Plan Project of Wenzhou Municipality(Grant Numbers:Y20180769 and Y20220078).
文摘Background:Hemoptysis patients with bronchial artery-pulmonary artery fistula(BPF)have a high incidence of poor prog-nosis.This study aimed to evaluate the diagnostic performance of computed tomography angiography(CTA)for detecting BPF in hemoptysis patients and to compare the clinical characteristics and computed tomography(CT)findings between patients with and without BPF.Methods:We retrospectively enrolled 201 consecutive patients with hemoptysis who underwent bronchial arterial emboli-zation in our hospital from January 2020 to November 2020.The clinical characteristics,preprocedural CT findings,and digital subtraction angiography(DSA)findings were recorded.Patients were categorized into BPF-positive and BPF-negative groups based on DSA results.The diagnostic accuracy of CTA for BPF detection was evaluated against that of DSA using receiver operating characteristic curve analysis.Differences in clinical and CT parameters between the two groups were assessed.Multivariate logistic regression analysis was used to discover the independent factors associated with the presence of BPF.Results:Among 201 patients with hemoptysis,DSA identified BPF in 75,while CTA identified BPF in 65.The diagnostic agreement between CTA and DSA for BPF detection was excellent(Kappa coefficient:κ=0.825,p<0.001).CTA demonstrated high sensitivity(0.827),specificity(0.976),and accuracy(0.920)for BPF detection.Multivariate logistic analysis identified the severity of pulmonary parenchymal lesion and bronchial artery tortuosity as independent predictors of BPF.Conclusions:Preprocedural CTA is a reliable examination to identify BPF in patients with hemoptysis.Pulmonary lesion severity and bronchial artery tortuosity are independent factors associated with the presence of BPF in patients with hemoptysis.
文摘Objective To evaluate the prevalence and one-year prognosis associated with frailty in a contemporary cohort of older patients with non-ST-elevation acute coronary syndrome(NSTEACS).Methods The IMPACT-TIMING-GO registry(IMPACT of Time of Intervention in patients with Myocardial Infarction with Non-ST seGment elevation.ManaGement and Outcomes)prospectively included 1020 patients with NSTEACS undergoing invasive coronary angiography between April and May 2021.For this sub-study,patients≥65 years were selected.Frailty was assessed according to FRAIL scale.We studied all-cause mortality and the composite of all-cause mortality or all-cause hospitalizations at one-year follow-up after discharge.Results Five hundred and sixty seven patients(mean age:75.8±6.7 years,28.2%women)were included:316(55.7%)were robust,183(32.3%)prefrail,and 68(12.0%)frail.Frail patients were significantly older,more often women,and presented a worse baseline clinical profile.There were no differences among groups regarding pretreatment with a P2Y12 inhibitor.An urgent angiography(<24 h)was less frequently performed in frail patients,with no differences regarding revascularization approach or in main in-hospital adverse events,although acute kidney disease occurred more frequently in frail patients.At 1-year follow-up,20 patients died(3.6%).Chronic kidney disease was independently associated with 1-year all-cause death,although a trend towards higher mortality was observed in frail patients(HR=3.01;95%CI:0.93-9.78;P=0.065).Frailty was independently associated with higher 1-year all-cause mortality or all-cause rehospitalizations(HR=2.23;95%CI:1.43-3.46;P<0.001)Conclusions In older patients with NSTEACS,frailty independently associates higher all-cause mortality or all-cause hospital admissions at one-year follow-up.
基金support from the Ministry of Education Singapore under its Academic Research Funding Tier 2 grant(MOE-T2EP30120-0001)Academic Research Funding Tier 1 grant(RG35/22)+1 种基金Singapore National Medical Research Council CS-NIG grant(MOH-CNIG24jan-0004)Guangzhou National Laboratory grant(GZNL2025C03014).
文摘Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hindered by the trade-off between transverse sampling rate and signal-to-noise ratio(SNR).This trade-off results in either a limited field of view(FOV)to maintain sampling density or loss of capillary details to fulfil FOV requirement.It also restricts microvascular quantifications,including flow velocimetry,which typically demand higher transverse sampling rate and SNR compared with standard qualitative OCTA.We introduce spectrally extended line field OCTA(SELF-OCTA),a cost-effective imag-ing modality that improves transverse sampling rate and SNR through spectrally encoded parallel sampling and in-creased signal acquired over longer periods,respectively.In the human skin and retina in vivo,we demonstrate its ad-vantages in achieving significantly extended FOV without sacrificing microvascular resolution,high sensitivity to slower flow without compromising FOV,and flow velocity quantification with the highest dynamic range,emphasizing that these features can be achieved with readily available and standard OCTA hardware settings.SELF-OCTA has the potential to make wide-field,high-resolution,quantitative angiographic imaging accessible to a wider population,thereby facilitating the early detection and follow-up of vascular-related diseases.
文摘BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch and central retinal arteries and veins,alongside anterior and posterior ischemic optic neuropathy.With the advent of optical coherence tomography angiography(OCTA),it is easy to identify these macular subclinical microvascular and structural changes.AIM To evaluate macular and peripapillary structural and microvasculature changes in patients with migraine with aura(MA),migraine without aura(MW),and healthy control(HC)participants using OCTA.METHODS In this observational cross-sectional study,we studied a total of 100 eyes:(1)32 eyes of 16 patients with MA;(2)36 eyes of 18 patients with MW,recruited based on the International Classification of Headache Disorders;and(3)32 eyes of 16 age and sex-matched healthy participants.Foveal flux,foveal avascular zone(FAZ),peripapillary flux obtained from OCTA,and foveal and peripapillary ganglion cell layer(GCL)thickness calculated via optical coherence tomography were compared among the groups.RESULTS The mean FAZ area measured in patients with MA and MW was significantly larger than that in the control participants(P=0.002).However,there was no significant difference between the FAZ of the MA and MW groups.Macular perfusion in the superficial capillary plexus in patients with MA was significantly lower compared to MW(P=0.0018)and HCs(P=0.002).There was also significant thinning of the GCL in patients with MA and MW(P=0.001)compared to HCs.However,there was no significant difference in temporal GCL thickness between the MA and MW groups.CONCLUSION Significant changes have been found in structural and microvascular parameters in patients with migraines compared with HCs.OCTA can serve as a valuable non-invasive imaging technique for identifying microcirculatory disturbances,aiding in better understanding the pathogenesis of different types of migraine and establishing their link with other ischemic retinal and systemic pathologies.
