Improving Neural Radiance Field using Near-Surface Sampling with Point Cloud Generation

Neural radiance field (NeRF) is an emerging view synthesis method that samples points in a three-dimensional (3D) space and estimates their existence and color probabilities. The disadvantage of NeRF is that it requires a long training time since it samples many 3D points. In addition, if one samples points from occluded regions or in the space where an object is unlikely to exist, the rendering quality of NeRF can be degraded. These issues can be solved by estimating the geometry of 3D scene. This paper proposes a near-surface sampling framework to improve the rendering quality of NeRF. To this end, the proposed method estimates the surface of a 3D object using depth images of the training set and sampling is performed around there only. To obtain depth information on a novel view, the paper proposes a 3D point cloud generation method and a simple refining method for projected depth from a point cloud. Experimental results show that the proposed near-surface sampling NeRF framework can significantly improve the rendering quality, compared to the original NeRF and a state-of-the-art depth-based NeRF method. In addition, one can significantly accelerate the training time of a NeRF model with the proposed near-surface sampling framework.Comment: 13 figures, 2 table

Anatomical physiological and biochemical processes involved in grapevine rootstock drought tolerance

In order to explore the drought resistance mechanism of grape rootstocks, two grape rootstock species, '1103P' (a drought-tolerant rootstock) and '101-14M' (drought-sensitive), were treated with moderate water deficit (field capacity of 45-50 %). Throughout the experimental period, the leaves of '1103P' showed a higher stomatal conductance (gs), relative water content and photosynthetic rate (Pn) than '101-14M', indicating '1103P' was more resistant to tolerant than '101-14M'. We propose that '1103P' could prevent water loss from leaves under drought conditions based on the discoveries that '1103P' had higher leaf phytohormone abscisic acid (ABA) content and leaf cuticular wax content, and smaller stomata aperture than those of '101-14M'. Additionally, the activities of H2O2-scavenging enzymes in leaves of '1103P' were higher than those of '101-14M' under drought conditions, indicating the lipid peroxidation induced by H2O2 of '1103P' was less serious than that of '101-14M'. Therefore, better water-saving and higher reactive oxygen species (ROS) scavenging abilities contributed together to stronger drought resistance of '1103P' than '101-14M'

Prognostic significance of the neutrophil to lymphocyte ratio in patients with non-small cell lung cancer: a systemic review and metaanalysis,”

Abstract: Neutrophil to Lymphocyte Ratio (NLR) was recently demonstrated as a useful index in predicting the prognosis of Non-Small Cell Lung Cancer (NSCLC). Thus, a meta-analysis was performed to demonstrate the relationship between NLR and overall survival (OS), progress-free survival (PFS) or disease free survival (DFS) in patients with NSCLC. We searched for relevant literatures in PubMed, EMBASE and Cochrane library and pooled the eligible studies and synthesized hazard ratios (HRs) using Stata 12.0. Final analysis of NSCLC patients from 12 eligible studies was performed. Combined HR suggested that high NLR had an unfavorable effect on patients' OS (n=1700 in 11 studies; HR= 1.43, 95% CI: 1.25-1.64; I^2=80.2%, P<0.01) and PFS (n=664 in 5 studies, HR=1.37, 95% CI: 1.07-1.74; I^2=70.8%, P=0.004). Subgroup analysis based on cutoff shown that, compared with other subgroups, the subgroup with a cutoff of 5 had a significantly poorer survival (HR=1.87, 95% CI 1.49-2.34) with less heterogeneity (I^2=21.3%, P=0.28). However, subgroup analysis based on treatment method indicated that the "surgery" subgroup seemed to have not a significant impact on survival (HR=1.32, 95% CI 0.99-1.77; I^2=80.0%, P=0.063) compared with the chemotherapy subgroup (HR=1.61, 95% CI 1.24-2.10; I^2=82.6%, P<0.01). Additionally, combined odds ratio (OR) suggested high NLR was associated inversely with response to treatment (n = 276 in 2 studies; OR = 1.73, 95% CI: 1.04-2.88; I^2=0%, P=0.40). This study suggests high NLR (especially with a cutoff of 5) seems to be associated with a worse prognosis in patients with NSCLC as well as a worse response to treatments

Prediction of steady-state plasma concentrations of olanzapine in Chinese Han in patients based on a retrospective population pharmacokinetic model

Purpose: To develop robust methods of establishing a population pharmacokinetics (Pop-PK) model of olanzapine, using existing hospital in-patient information, in order to predict the steady-state plasma concentration of olanzapine tablets in Chinese Han inpatients, thus providing guidance for individualized therapy for mental disorders.Methods: A retrospective study analyzing and predicting the steady-state plasma olanzapineconcentration was performed using nonlinear mixed-effect modeling (Phoenix® NLME8). The effects of ten potential covariates, including age, gender, Body Mass Index, fasting lipid, family history, alcohol and smoking status in 107 Chinese Han patients with steady-state plasma olanzapine concentration were collected from the hospital information system (HIS) in Wuhan Mental Health Center from Feb 2017 to Jul 2019.Results: The final model was validated using bootstrap and visual predictive check (VPC) and was found to fit the one-compartment mixed error model. Smoking status was found to be the only factor affecting olanzapine tablets clearance. The standard Pop-PK parameters apparent volume of distribution (VL/F) and clearance (CL/F) were 223 L and 12.4 Lꞏh-1, respectively.Conclusion: The Pop-PK model for olanzapine established with the data from HIS is effective inpredicting the plasma olanzapine tablets concentration of individual Chinese in-patients. This Pop-PK model approach can now be adapted to optimize other antipsychotic drugs