152 research outputs found
Efficient Halftoning via Deep Reinforcement Learning
Halftoning aims to reproduce a continuous-tone image with pixels whose
intensities are constrained to two discrete levels. This technique has been
deployed on every printer, and the majority of them adopt fast methods (e.g.,
ordered dithering, error diffusion) that fail to render structural details,
which determine halftone's quality. Other prior methods of pursuing visual
pleasure by searching for the optimal halftone solution, on the contrary,
suffer from their high computational cost. In this paper, we propose a fast and
structure-aware halftoning method via a data-driven approach. Specifically, we
formulate halftoning as a reinforcement learning problem, in which each binary
pixel's value is regarded as an action chosen by a virtual agent with a shared
fully convolutional neural network (CNN) policy. In the offline phase, an
effective gradient estimator is utilized to train the agents in producing
high-quality halftones in one action step. Then, halftones can be generated
online by one fast CNN inference. Besides, we propose a novel anisotropy
suppressing loss function, which brings the desirable blue-noise property.
Finally, we find that optimizing SSIM could result in holes in flat areas,
which can be avoided by weighting the metric with the contone's contrast map.
Experiments show that our framework can effectively train a light-weight CNN,
which is 15x faster than previous structure-aware methods, to generate
blue-noise halftones with satisfactory visual quality. We also present a
prototype of deep multitoning to demonstrate the extensibility of our method
Supercurrent, Multiple Andreev Reflections and Shapiro Steps in InAs Nanosheet Josephson Junctions
High-quality free-standing InAs nanosheets are emerging layered semiconductor
materials with potentials in designing planar Josephson junction devices for
novel physics studies due to their unique properties including strong
spin-orbit couplings, large Land\'e g-factors and the two dimensional nature.
Here, we report an experimental study of proximity induced superconductivity in
planar Josephson junction devices made from free-standing InAs nanosheets. The
nanosheets are grown by molecular beam epitaxy and the Josephson junction
devices are fabricated by directly contacting the nanosheets with
superconductor Al electrodes. The fabricated devices are explored by
low-temperature carrier transport measurements. The measurements show that the
devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and
a good quality superconductor-semiconductor interface. The superconducting
characteristics of the Josephson junctions are investigated at different
magnetic fields and temperatures, and are analyzed based on the
Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of ac Josephson effect
are also conducted under microwave radiations with different radiation powers
and frequencies, and integer Shapiro steps are observed. Our work demonstrates
that InAs nanosheet based hybrid devices are desired systems for investigating
forefront physics, such as the two-dimensional topological superconductivity
Multiparametric MRI combined with liver volume for quantitative evaluation of liver function in patients with cirrhosis
PURPOSEWe aimed to establish a liver function evaluation model by combining multiparametric magnetic resonance imaging (MRI) with liver volume (LV) and further verify the effectiveness of the model to evaluate liver function.METHODSThis retrospective study included 101 consecutive cirrhosis patients (69 cases for modeling group and 32 cases for validation group) who underwent gadoxetic acid-enhanced MRI. Five signal intensity parameters were obtained by measuring the signal intensities of the liver, spleen, and erector spinae before and 20 minutes after gadoxetic acid disodium enhancement. The diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were obtained from intravoxel incoherent motion diffusion-weighted imaging. The LV parameters (Vliver, Vspleen, and Vliver/Vspleen) were obtained using 3-dimensional image generation software. The most effective parameter was selected from each of the 3 methods, and a multivariate regression model for liver function evaluation was established and validated.RESULTSIn the modeling group, relative enhancement (RE), D*, and Vliver/Vspleen showed significant differences among the different liver function groups (P < .001). Receiver operating characteristic analysis showed that these parameters had the highest area under the curve (AUC) values for distinguishing Child-Pugh A from Child-Pugh B and C groups (0.917, 0.929, and 0.885, respectively). The following liver function model was obtained by multivariate regression analysis: F(x)=3.96 − 1.243 (RE) − 0.034 (D*) − 0.080 (Vliver/Vspleen) (R2=0.811, P < .001). In the patients with cirrhosis, the F(x) of Child-Pugh A, B, and C were 1.16 ± 0.44, 1.95 ± 0.29, and 2.79 ± 0.38, respectively. In the validation group, the AUC for F(x) to distinguish Child-Pugh A from Child-Pugh B and C was 0.973.CONCLUSIONCombining multiparametric MRI with LV effectively distinguished patients with different ChildPugh grades. This model could hence be useful as a novel radiological marker to estimate the liver function
O2ATH: An OpenMP Offloading Toolkit for the Sunway Heterogeneous Manycore Platform
The next generation Sunway supercomputer employs the SW26010pro processor,
which features a specialized on-chip heterogeneous architecture. Applications
with significant hotspots can benefit from the great computation capacity
improvement of Sunway many-core architectures by carefully making intensive
manual many-core parallelization efforts. However, some legacy projects with
large codebases, such as CESM, ROMS and WRF, contain numerous lines of code and
do not have significant hotspots. The cost of manually porting such
applications to the Sunway architecture is almost unaffordable. To overcome
such a challenge, we have developed a toolkit named O2ATH. O2ATH forwards GNU
OpenMP runtime library calls to Sunway's Athread library, which greatly
simplifies the parallelization work on the Sunway architecture.O2ATH enables
users to write both MPE and CPE code in a single file, and parallelization can
be achieved by utilizing OpenMP directives and attributes. In practice, O2ATH
has helped us to port two large projects, CESM and ROMS, to the CPEs of the
next generation Sunway supercomputers via the OpenMP offload method. In the
experiments, kernel speedups range from 3 to 15 times, resulting in 3 to 6
times whole application speedups.Furthermore, O2ATH requires significantly
fewer code modifications compared to manually crafting CPE functions.This
indicates that O2ATH can greatly enhance development efficiency when porting or
optimizing large software projects on Sunway supercomputers.Comment: 15 pages, 6 figures, 5 tables
Isolation and Identification of Pediococcus lactis in Human Intestinal Tract and Its Performance Analysis of Fermented Goji Berry Juice
In order to obtain candidate strains with strong colonization ability and excellent fermentation performance of goji berry juice, 3 strains of lactic acid bacteria were isolated and screened from human intestinal tract. They were identified by morphological, physiological and biochemical, 16S rDNA sequence analysis and phylogenetic tree construction, and their acid resistance, bile salt resistance, artificial gastric fluid, intestinal fluid resistance and fermentation performance were studied. The results showed that all three strains were identified as Pediococcus lactis, numbered NXU_220218, NXU_220219 and NXU_220220, respectively. The growth rate from 2 to 8 h, the ability of NXU 220218 to produce acid was stronger, and the tolerance to acid, bile salt and artificial gastric juice was better than NXU 220219 and NXU 220220. The survival rate of NXU_220218 was 67% at pH2, 65% in bovine bile salt at 0.3% concentration, 72% tolerance to artificial gastric juice, and 95% tolerance to artificial intestinal juice. Finally, the NXU_220218 strain was inoculated and used in the preparation of fermented goji berry juice. It was found that the reducing sugar content and the free radical scavenging rate in the fermented goji berry juice were significantly reduced and increased, respectively, compared with the unfermented goji berry juice, indicating that the NXU_220218 strain had good fermentation performance for goji berry juice and could be used as a candidate strain of lactic acid bacteria for the fermentation of goji berry juice
Evaluating the importation of yellow fever cases into China in 2016 and strategies used to prevent and control the spread of the disease
During the yellow fever epidemic in Angola in 2016, cases of yellow fever were reported in China for the first time. The 11 cases, all Chinese nationals returning from Angola, were identified in March and April 2016, one to two weeks after the peak of the Angolan epidemic. One patient died; the other 10 cases recovered after treatment. This paper reviews the epidemiological characteristics of the 11 yellow fever cases imported into China. It examines case detection and disease control and surveillance, and presents recommendations for further action to prevent additional importation of yellow fever into China
Bibliometric analysis of ferroptosis: a comprehensive evaluation of its contribution to cancer immunity and immunotherapy
BackgroundIn the past 5 years, ferroptosis-associated cancer immunity has been attracted significant research interest.ObjectiveThis study was performed to identify and analyze the global output trend for ferroptosis in cancer immunity.MethodsRelevant studies were retrieved from the Web of Science Core Collection on Feb 10th, 2023. The VOSviewer and Histcite softwares were utilized to perform the visual bibliometric and deep mining analyses.ResultsA total of 694 studies (530 articles (76.4%) and 164 (23.6%) review articles) were retrieved from the Web of Science Core Collection for visualization analyses. The top 3 key keywords were ferroptosis, prognosis and immunotherapy. The top 30 local citation score (LCS) authors were all collaborators of Zou Weiping. Deep mining of 51 nanoparticle-related articles showed that BIOMATERIALS was the most popular journal. The primary goal of gene signatures related to ferroptosis and cancer immunity was to establish prognostic predictions.ConclusionThere has been a significant increase in ferroptosis-associated immune publications in the recent 3 years. The key research hotspots include mechanisms, prediction and therapeutic outcomes. The most influential article was from the Zou Weiping’s group, which proposed that system xc-mediated ferroptosis is induced by CD8(+) T cell-secreted IFNγ after PD-L1 blockage for immunotherapy. The frontier of research in the field of ferroptosis-associated immune is the study on nanoparticle and gene signature The limitation of this bibliometric study is that publications on this topic are few
Forest Fire Prevention Early Warning Method Based on Fuzzy Bayesian Network
In the environment of large forest, the factors causing fire are nonlinear and uncertain. If the data collected by the sensor is simply analyzed and compared, the false alarm rate will be higher. How to combine the data of several sensors for effective fire warning is a difficult point. In order to improve the accuracy of prediction, aiming at the shortcomings of traditional forest fire prevention early warning system, we propose a forest fire prevention early warning method based on fuzzy Bayesian network. Firstly, we combine the fuzzy control system and the Bayesian network in series, and pre-process the collected sensor data. The pre-processed data is sent to the previously trained Bayesian network for processing. Then the calculated open fire probability, smoldering fire probability, and no fire probability are used as input data of fuzzy control system, and fuzzy inference is performed. Finally, we de-fuzzify the results of fuzzy reasoning and get the probability of fire. Simulation results show that our method can effectively combine the data collected by multiple sensors, quickly and accurately determine fire occurrence probability, improve the accuracy of forest fire prevention warning, and reduce the false positive rate
Chemotherapy combined with radiotherapy can benefit more unresectable HCC patients with portal and/or hepatic vein invasion: a retrospective analysis of the SEER database
BackgroundThe purpose of this study is to evaluate the effects of chemotherapy and radiotherapy on the prognosis of unresectable HCC patients with portal and/or hepatic vein invasion.MethodsA retrospective analysis of unresectable HCC patients with portal and/or hepatic vein invasion registered in the Surveillance, Epidemiology, End Results (SEER) database was performed. The propensity score-matching (PSM) method was used to balance differences between groups. Overall survival (OS) and cancer-specific survival (CSS) were the interesting endpoints. OS was calculated from the date of diagnosis to the date of death caused by any cause or the last follow-up. CSS was defined as the interval between the date of diagnosis and date of death due only to HCC or last follow-up. OS and CSS were analyzed by using Kaplan-Meier analysis, Cox proportional hazards model, and Fine-Gray competing-risk model.ResultsA total of 2,614 patients were included. 50.2% patients received chemotherapy or radiotherapy and 7.5% patients received both chemotherapy and radiotherapy. Compared to the untreated group, chemotherapy or radiotherapy (COR) (HR = 0.538, 95% CI 0.495-0.585, p < 0.001) and chemotherapy and radiotherapy (CAR) (HR = 0.371, 95% CI 0.316-0.436, p < 0.001) showed better OS. In the COR group, Cox analysis results showed AFP, tumor size, N stage and M stage were independent risk factor of OS. Competing-risk analysis results showed AFP, tumor size and M stage were independent risk factor of CSS. In the CAR group, AFP and M stage were independent risk factors of OS. Competing-risk analysis results showed M stage were independent risk factor of CSS. Kaplan Meier analysis showed chemotherapy combined with radiotherapy significantly improves OS (10.0 vs. 5.0 months, p < 0.001) and CSS (10.0 vs. 6.0 months, p = 0.006) than monotherapy.ConclusionAFP positive and distant metastasis are the main risk factors affecting OS and CSS of unresectable HCC patients with portal and/or hepatic vein invasion. Chemotherapy combined with radiotherapy significantly improves OS and CSS of unresectable HCC patients with portal and/or hepatic vein invasion
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