53 research outputs found
Morphable Diffusion: 3D-Consistent Diffusion for Single-image Avatar Creation
Recent advances in generative diffusion models have enabled the previously
unfeasible capability of generating 3D assets from a single input image or a
text prompt. In this work, we aim to enhance the quality and functionality of
these models for the task of creating controllable, photorealistic human
avatars. We achieve this by integrating a 3D morphable model into the
state-of-the-art multi-view-consistent diffusion approach. We demonstrate that
accurate conditioning of a generative pipeline on the articulated 3D model
enhances the baseline model performance on the task of novel view synthesis
from a single image. More importantly, this integration facilitates a seamless
and accurate incorporation of facial expression and body pose control into the
generation process. To the best of our knowledge, our proposed framework is the
first diffusion model to enable the creation of fully 3D-consistent,
animatable, and photorealistic human avatars from a single image of an unseen
subject; extensive quantitative and qualitative evaluations demonstrate the
advantages of our approach over existing state-of-the-art avatar creation
models on both novel view and novel expression synthesis tasks. The code for
our project is publicly available.Comment: [CVPR 2024] Project page:
https://xiyichen.github.io/morphablediffusion
A Coarse-to-fine Framework for Automated Kidney and Kidney Tumor Segmentation from Volumetric CT Images
Automatic semantic segmentation of kidney and kidney tumor is a promising tool for the treatment of kidney cancer. Due to the wide variety in kidney and kidney tumor morphology, it is still a great challenge to complete accurate segmentation of kidney and kidney tumor. We propose a new framework based on our previous work accepted by MICCAI2019, which is a coarse-to-fine segmentation framework to realize accurate and fast segmentation of kidney and kidney tumor
Development of an integrated cardiac rehabilitation program to improve the adaptation level of patients after acute myocardial infarction
BackgroundIndividual’s adaptation following acute myocardial infarction (AMI) and low attendance of whole-course cardiac rehabilitation (CR) are significant issues. For optimal health post AMI, an integrated CR program aiming at individual’s adaptive behaviors is imperative for improving the CR efficiency and patients’ outcomes. This study aims to develop theory-guided interventions to increase CR attendance and adaptation level of patients post-AMI.MethodsThis study was conducted in a tertiary hospital from July 2021 to September 2022 in Shanghai China. Guided by the theory of adaptation to chronic illness (ACI theory), the study followed the Intervention mapping (IM) framework to develop the interventions for CR program. Four phases included: (1) needs assessment of patients and facilitators using a cross-sectional study and semi-structured, in-depth interviews, (2) identification of implementation outcomes and performance objectives, (3) selection of theoretical methods to explain the mechanism of patients’ adaptive behaviors and to use for behavior change, and (4) development of implementation protocol from the results of the previous phases.ResultsA total of 226 AMI patient-caregivers paired samples were eligible for the data analysis, 30 AMI patients participated in the qualitative inquiry, 16 experts in the CR field evaluated the implementation protocol, and 8 AMI patients commented on the practical interventions. Following the IM framework, an integrated cardiac rehabilitation program using mHealth strategies was developed for AMI patients to facilitate CR attendance and completion, to improve their adaptation level and health outcomes.ConclusionUsing the IM framework and ACI theory, an integrated CR program was developed to help guide the behavior change and improve adaptation among AMI patients. The preliminary findings suggest that further intervention in enhancing the combination of three-stage CR is required. A feasibility study will be conducted to assess the acceptability and effectiveness of this generated CR intervention
Ultrafast Dynamics for Electron Photodetachment from Aqueous Hydroxide
Charge-transfer-to-solvent (CTTS) reactions of hydroxide induced by 200 nm
monophotonic or 337 nm and 389 nm biphotonic excitation of this anion in
aqueous solution have been studied by means of pump-probe ultrafast laser
spectroscopy. Transient absorption kinetics of the hydrated electron, eaq-,
have been observed, from a few hundred femtoseconds out to 600 ps, and studied
as function of hydroxide concentration and temperature. The geminate decay
kinetics are bimodal, with a fast exponential component (ca. 13 ps) and a
slower power "tail" due to the diffusional escape of the electrons. For the
biphotonic excitation, the extrapolated fraction of escaped electrons is 1.8
times higher than for the monophotonic 200 nm excitation (31% vs. 17.5% at 25
oC, respectively), due to the broadening of the electron distribution. The
biphotonic electron detachment is very inefficient; the corresponding
absorption coefficient at 400 nm is < 4 cm TW-1 M-1 (assuming unity quantum
efficiency for the photodetachment). For [OH-] between 10 mM and 10 M, almost
no concentration dependence of the time profiles of solvated electron kinetics
was observed. At higher temperature, the escape fraction of the electrons
increases with a slope of 3x10-3 K-1 and the recombination and
diffusion-controlled dissociation of the close pairs become faster. Activation
energies of 8.3 and 22.3 kJ/mol for these two processes were obtained. The
semianalytical theory of Shushin for diffusion controlled reactions in the
central force field was used to model the geminate dynamics. The implications
of these results for photoionization of water are discussed.Comment: 44 pages, 9 figures; supplement: 4 pages, 7 figures; to be submitted
to J. Chem. Phy
Selective oxidation of methane to C2+ products over Au-CeO2 by photon-phonon co-driven catalysis.
Direct methane conversion to high-value chemicals under mild conditions is attractive yet challenging due to the inertness of methane and the high reactivity of valuable products. This work presents an efficient and selective strategy to achieve direct methane conversion through the oxidative coupling of methane over a visible-responsive Au-loaded CeO2 by photon-phonon co-driven catalysis. A record-high ethane yield of 755 μmol h−1 (15,100 μmol g−1 h−1) and selectivity of 93% are achieved under optimised reaction conditions, corresponding to an apparent quantum efficiency of 12% at 365 nm. Moreover, the high activity of the photocatalyst can be maintained for at least 120 h without noticeable decay. The pre-treatment of the catalyst at relatively high temperatures introduces oxygen vacancies, which improves oxygen adsorption and activation. Furthermore, Au, serving as a hole acceptor, facilitates charge separation, inhibits overoxidation and promotes the C-C coupling reaction. All these enhance photon efficiency and product yield
Electron Photodetachment from Aqueous Anions. II. Ionic Strength Effect on Geminate Recombination Dynamics and Quantum Yield for Hydrated Electron
In concentrated solutions of NaClO4 and Na2SO4, the quantum yield for free
electron generated by detachment from photoexcited anions (such as I-, OH-,
ClO^4-, and [SO3]^2-) linearly decreases by 6-12% per 1 M ionic strength. In 9
M sodium perchlorate solution, this quantum yield decreases by roughly an order
of magnitude. Ultrafast kinetic studies of 200 nm photon induced electron
detachment from Br-, HO- and [SO3]^2- suggest that the prompt yield of
thermalized electron does not change in these solutions; rather, the ionic
strength effect originates in more efficient recombination of geminate pairs.
Within the framework of the recently proposed mean force potential (MFP) model
of charge separation dynamics in such photosystems, the observed changes are
interpreted as an increase in the short-range attractive potential between the
geminate partners. Association of sodium cation(s) with the electron and the
parent anion is suggested as the most likely cause for the observed
modification of the MFP. Electron thermalization kinetics suggest that the
cation associated with the parent anion (by ion pairing and/or ionic atmosphere
interaction) is passed to the detached electron in the course of the
photoreaction. The precise atomic-level mechanism for the ionic strength effect
is presently unclear; any further advance is likely to require the development
of an adequate quantum molecular dynamics model.Comment: 40 pages, 10 figures + supplement 2 pages, 9 figures; will be
submitted, in a modified form, to J. Phys. Chem
Diagnostic Value of Methylated Septin9 for Colorectal Cancer Detection
BackgroundMethylated Septin9 (mSEPT9) has been suggested as a reliable biomarker in colorectal cancer (CRC) detection. We aimed to determine the diagnostic value of mSEPT9 for CRC detection in Chinese patients. In addition, we compared the diagnostic efficacy of mSEPT9 to traditional screening method [fecal occult blood test (FOBT)] and two biomarkers [carcinoembryonic antigen (CEA) and carbohydrate antigen-199 (Ca-199)].MethodsOverall 248 subjects including 123 patients with CRC and 125 controls were included. Plasma and fecal samples were collected for CEA, Ca-199, mSEPT9, and FOBT tests. Sensitivity and specificity were calculated to evaluate the diagnostic efficacy of each method; receiver operating characteristic (ROC) curve was plotted for the assessment of diagnostic accuracy, and comparisons among FOBT, mSEPT9, and the combination were assessed through area under the ROC curve (AUC).ResultsmSEPT9 achieved overall sensitivity and specificity of 61.8% [95% confidence interval (CI): 53.0–69.9%] and 89.6% (83.0–93.8%), respectively, with an AUC value of 0.757 (95% CI: 0.701–0.807), superior to FOBT [sensitivity: 61.4% (50.9–70.9%); specificity: 70.3% (59.1–79.5%); AUC: 0.658 (0.578–0.723)], CEA [sensitivity: 35.0% (27.1–43.7%); specificity: 62.6% (53.8–70.7%); AUC: 0.485 (0.411–0.559)], and Ca-199 [sensitivity: 17.9% (12.1–25.6%); specificity: 55.7% (48.9–64.1%); AUC: 0.353 (0.283–0.423)]. The combination of mSEPT9 and FOBT further improved sensitivity and AUC value of 84.1% (75.1–90.3%) and 0.807 (0.752–0.863), respectively, while specificity was declined to 62.2% (50.8–72.4%).ConclusionmSEPT9 demonstrated best diagnostic ability in CRC detection compared with FOBT, CEA, and Ca-199. The combination of mSEPT9 and FOBT further improved diagnostic sensitivity especially for early stage disease, which may provide a new approach for future CRC screening, though further investigations are warranted
Prognosis Prediction of Colorectal Cancer Using Gene Expression Profiles
Background: Investigation on prognostic markers for colorectal cancer (CRC) deserves efforts, but data from China are scarce. This study aimed to build a prognostic algorithm using differentially expressed gene (DEG) profiles and to compare it with the TNM staging system in their predictive accuracy for CRC prognosis in Chinese patients.Methods: DEGs in six paired tumor and corresponding normal tissues were determined using RNA-Sequencing. Subsequently, matched tumor and normal tissues from 127 Chinese patients were assayed for further validation. Univariate and multivariate Cox regressions were used to identify informative DEGs. A predictive index (PI) was derived as a linear combination of the products of the DEGs and their Cox regression coefficients. The combined predictive accuracy of the DEGs-based PI and tumors' TNM stages was also examined by a logistic regression model including the two predictors. The predictive performance was evaluated with the area under the receiver operating characteristics (AUCs).Results: Out of 75 candidate DEGs, we identified 10 DEGs showing statistically significant associations with CRC survival. A PI based on these 10 DEGs (PI-10) predicted CRC survival probability more accurately than the TNM staging system [AUCs for 3-year survival probability 0.73 (95% confidence interval: 0.64, 0.81) vs. 0.68 (0.59, 0.76)] but comparable to a simplified PI (PI-5) using five DEGs (LOC646627, BEST4, KLF9, ATP6V1A, and DNMT3B). The predictive accuracy was improved further by combining PI-5 and the TNM staging system [AUC for 3-year survival probability: 0.72 (0.63, 0.80)].Conclusion: Prognosis prediction based on informative DEGs might yield a higher predictive accuracy in CRC prognosis than the TNM staging system does
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