436 research outputs found
SwIPE: Efficient and Robust Medical Image Segmentation with Implicit Patch Embeddings
Modern medical image segmentation methods primarily use discrete
representations in the form of rasterized masks to learn features and generate
predictions. Although effective, this paradigm is spatially inflexible, scales
poorly to higher-resolution images, and lacks direct understanding of object
shapes. To address these limitations, some recent works utilized implicit
neural representations (INRs) to learn continuous representations for
segmentation. However, these methods often directly adopted components designed
for 3D shape reconstruction. More importantly, these formulations were also
constrained to either point-based or global contexts, lacking contextual
understanding or local fine-grained details, respectively--both critical for
accurate segmentation. To remedy this, we propose a novel approach, SwIPE
(Segmentation with Implicit Patch Embeddings), that leverages the advantages of
INRs and predicts shapes at the patch level--rather than at the point level or
image level--to enable both accurate local boundary delineation and global
shape coherence. Extensive evaluations on two tasks (2D polyp segmentation and
3D abdominal organ segmentation) show that SwIPE significantly improves over
recent implicit approaches and outperforms state-of-the-art discrete methods
with over 10x fewer parameters. Our method also demonstrates superior data
efficiency and improved robustness to data shifts across image resolutions and
datasets. Code is available on Github.Comment: Accepted to 2023 International Conference on Medical Image Computing
and Computer Assisted Intervention (MICCAI'23
Analysis of shallow-groundwater dynamic responses to water supply change in the Haihe River plain
When the middle route of the South-to-North Water Diversion Project is completed, the water supply pattern of the Haihe River plain in North China will change significantly due to the replenishment of water sources and groundwater-exploitation control. The water-cycle-simulation model â MODCYCLE, has been used in simulating the groundwater dynamic balance for 2001â2010. Then different schemes of water supply in 2020 and 2030 were set up to quantitatively simulate the shallow-groundwater dynamic responses in the future. The results show that the total shallow-groundwater recharge is mainly raised by the increases in precipitation infiltration and surface-water irrigation infiltration. Meanwhile, the decrease of groundwater withdrawal contributes to reduce the total discharge. The rechargeâdischarge structure of local groundwater was still in a negative balance but improved gradually. The shallow-groundwater level in most parts was still falling before 2030, but more slowly. This study can benefit the rational exploitation of water resources in the Haihe River plain
A Co9S8 microsphere and N-doped carbon nanotube composite host material for lithium-sulfur batteries
Lithium-sulfur batteries have emerged as extraordinarily favorable energy storage devices due to their high specific capacity and energy density, safety and low cost. Unfortunately, the wide applications of lithium-sulfur batteries are hampered by several issues, such as the low electronic conductivity and slow redox kinetics, serious volumetric expansion and polysulfide âshuttle effectâ. To overcome these issues, in our work, we design and synthesize a composite sulfur host material of Co9S8 microspheres and N-doped carbon nanotubes, where the metallic sulfide Co9S8 with a good conductivity enables the immobilization of the polar lithium polysulfides owing to the strong polar chemisorptive capability, and the one dimensional N-doped carbon nanotubes can provide channels for fast electron and lithium-ion transport. As the lithium polysulfides are well confined, and the redox conversions are promoted, the Co9S8@N-CNTs/S-based lithium-sulfur battery possesses a superior energy storage performance, exhibiting a large specific capacity of 1233 mAh g-1 at 0.1 C and an outstanding cyclic performance, with a low decay of 0.045% per cycle and a Coulombic efficiency of more than 99% after 1000 cycles
Near-Infrared Super Resolution Imaging with Metallic Nanoshell Particle Chain Array
We propose a near-infrared super resolution imaging system without a lens or
a mirror but with an array of metallic nanoshell particle chain. The imaging
array can plasmonically transfer the near-field components of dipole sources in
the incoherent and coherent manners and the super resolution images can be
reconstructed in the output plane. By tunning the parameters of the metallic
nanoshell particle, the plasmon resonance band of the isolate nanoshell
particle red-shifts to the near-infrared region. The near-infrared super
resolution images are obtained subsequently. We calculate the field intensity
distribution at the different planes of imaging process using the finite
element method and find that the array has super resolution imaging capability
at near-infrared wavelengths. We also show that the image formation highly
depends on the coherence of the dipole sources and the image-array distance.Comment: 15 pages, 6 figure
The global epidemiology of hepatitis E virus infection: A systematic review and meta-analysis
Background and aims: Hepatitis E virus (HEV), as an emerging zoonotic pathogen, is a leading cause of acute viral hepatitis worldwide, with a high risk of developing chronic infection in immunocompromised patients. However, the global epidemiology of HEV infection has not been comprehensively assessed. This study aims to map the global prevalence and identify the risk factors of HEV infection by performing a systematic review and meta-analysis. Methods: A systematic searching of articles published in Medline, Embase, Web of science, Cochrane and Google scholar databases till July 2019 was conducted to identify studies with HEV prevalence data. Pooled prevalence among different countries and continents was estimated. HEV IgG seroprevalence of subgroups was compared and risk factors for HEV infection were evaluated using odd ratios (OR). Results: We identified 419 related studies which comprised of 1Â 519Â 872 individuals. A total of 1Â 099Â 717 participants pooled from 287 studies of general population estimated a global anti-HEV IgG seroprevalence of 12.47% (95% CI 10.42-14.67; I2Â =Â 100%). Notably, the use of ELISA kits from different manufacturers has a substantial impact on the global estimation of anti-HEV IgG seroprevalence. The pooled estimate of anti-HEV IgM seroprevalence based on 98 studies is 1.47% (95% CI 1.14-1.85; I2Â =Â 99%). The overall estimate of HEV viral RNA-positive rate in general population is 0.20% (95% CI 0.15-0.25; I2Â =Â 98%). Consumption of raw meat (PÂ =.0001), exposure to soil (PÂ <.0001), blood transfusion (PÂ =.0138), travelling to endemic areas (PÂ =.0244), contacting with dogs (PÂ =.0416), living in rural areas (PÂ =.0349) and receiving education less than elementary school (PÂ <.0001) were identified as risk factors for anti-HEV IgG positivity. Conclusions: Globally, approximately 939Â million corresponding to 1 in 8 individuals have ever experienced HEV infection. 15-110Â million individuals have recent or ongoing HEV infection. Our study highlights the substantial burden of HEV infection and calls for increasing routine screening and preventive measures
MDA5 against enteric viruses through induction of interferon-like response partially via the JAK-STAT cascade
Enteric viruses including hepatitis E virus (HEV), human norovirus (HuNV), and rotavirus are causing global health issues. The host interferon (IFN) response constitutes the first-line defense against viral infections. Melanoma Differentiation-Associated protein 5 (MDA5) is an important cytoplasmic receptor sensing viral infection to trigger IFN production, and on the other hand it is also an IFN-stimulated gene (ISG). In this study, we investigated the effects and mode-of-action of MDA5 on the infection of enteric viruses. We found that MDA5 potently inhibited HEV, HuNV and rotavirus replication in multiple cell models. Overexpression of MDA5 induced transcription of important antiviral ISGs through IFN-like response, without triggering of functional IFN production. Interestingly, MDA5 activates the expression and phosphorylation of STAT1, which is a central component of the JAK-STAT cascade and a hallmark of antiviral IFN response. However, genetic silencing of STAT1 or pharmacological inhibition of the JAK-STAT cascade only partially attenuated the induction of ISG transcription and the antiviral function of MDA5. Thus, we have demonstrated that MDA5 effectively inhibits HEV, HuNV and rotavirus replication through provoking a non-canonical IFN-like response, which is partially dependent on JAK-STAT cascade
Systematically comparing COVID-19 with the 2009 influenza pandemic for hospitalized patients
Objectives: This study aimed to comprehensively compare the clinical features of hospitalized COVID-19 patients with hospitalized 2009 influenza pandemic patients. Methods: Medline, Embase, Web of Science, Cochrane CENTRAL, and Google scholar were systematically searched to identify studies related to COVID-19 and the 2009 influenza pandemic. The pooled incidence rates of clinical features were estimated using the DerSimonian-Laird random-effects model with the Freeman-Tukey double arcsine transformation method. Results: The incidence rates of fever, cough, shortness of breath, sore throat, rhinorrhea, myalgia/muscle pain, or vomiting were found to be significantly higher in influenza patients when compared with COVID-19 patients. The incidence rates of comorbidities, including cardiovascular disease/hypertension and diabetes, were significantly higher in COVID-19 compared with influenza patients. In contrast, comorbidities such as asthma, chronic obstructive pulmonary disease, and immunocompromised conditions were significantly more common in influenza compared with COVID-19 patients. Unexpectedly, the estimated rates of intensive care unit admission, treatment with extracorporeal membrane oxygenation, treatment with antibiotics, and fatality were comparable between hospitalized COVID-19 and 2009 influenza pandemic patients. Conclusions: This study comprehensively estimated the differences and similarities of the clinical features and burdens of hospitalized COVID-19 and 2009 influenza pandemic patients. This information will be important to better understand the current COVID-19 pandemic
CDK5RAP2 stimulates microtubule nucleation by the Îł-tubulin ring complex
A conserved Îł-tubulin complexâbinding domain in CDK5RAP2 stimulates the microtubule-nucleating activity of Îł-TuRC
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